A sealant and a method for preparing the same

Abstract

The present application relates to a kind of sealant and its preparation method, the raw materials of the sealant include the following components: butyl rubber, polyisobutylene composition, silane end-capped polymer and molecular sieve, the silane end-capped polymer is selected from one or several combinations of silane modified polyolefin, silane modified polyether and silane modified polyisobutylene.The sealant provided by the present application has excellent weather resistance and water vapor barrier performance, the preparation process is simple and safe, and is suitable for industrialization.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials and relates to a sealant and its preparation method. Background Technology

[0002] Butyl sealant is an adhesive with butyl rubber (IIR) as the main material. The raw material butyl rubber is a synthetic rubber composed of isobutylene (97% to 99%) and a small amount of isoprene (1% to 3%). However, rubber itself does not have adhesive properties, so it needs to be mixed with polyisobutylene to improve adhesion, anti-aging properties, weather resistance, etc. The final butyl sealant has high molecular polarity, low unsaturated bond content, and low molecular chain activity, thus exhibiting good chemical and thermal stability.

[0003] In the photovoltaic field, butyl sealant is mainly used for photovoltaic module encapsulation. Butyl sealant has good compatibility with conventional encapsulation materials such as EVA and POE films, and is used in conjunction with these films as an auxiliary encapsulation material. Using butyl sealant for edge sealing significantly improves the module's anti-PID performance, effectively delaying moisture erosion in outdoor high-temperature and high-humidity environments. It is suitable for highly moisture-sensitive HJT and perovskite cells, and can also be used in thin-film photovoltaic modules (CIGS / CdTe / GaAs / a-Si) and flexible modules. However, the iteration of battery technology has placed higher demands on the waterproof performance of module encapsulation. The TCO film layer of HJT has weak adhesion to traditional encapsulation films and is sensitive to moisture. The perovskite absorber layer is unstable, and moisture intrusion easily causes battery degradation. Therefore, these new battery materials are more sensitive to moisture and require better moisture protection; otherwise, moisture will adversely affect the module's output power and lifespan. Because existing encapsulation materials have poor moisture barrier properties, internal electronic components are exposed to moisture in the air and corrode, leading to reduced electrical performance and even affecting module lifespan. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a sealant with excellent weather resistance and water vapor barrier properties, as well as a method for its preparation.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] The first objective of this invention is to provide a sealant, the raw materials for which the sealant is prepared include the following components: butyl rubber, polyisobutylene composition, silane-modified polymer, and molecular sieve, wherein the silane-modified polymer is selected from one or a combination of several of silane-modified polyolefins, silane-modified polyethers, and silane-modified polyisobutylene.

[0007] Preferably, the silane-modified polymer is selected from a combination of silane-modified polyolefin and silane-modified polyisobutylene or silane-modified polyolefin and silane-modified polyether.

[0008] Preferably, the mass ratio of the silane-modified polyolefin to the silane-modified polyisobutylene and the mass ratio of the silane-modified polyolefin to the silane-modified polyether are each and independently 1:(0.1-2), more preferably 1:(0.1-1).

[0009] Preferably, the content of the silane-modified polymer is 5 to 20 parts by weight, more preferably 8 to 15 parts.

[0010] Preferably, the molecular sieve is one or a combination of several of 3A molecular sieve, 4A molecular sieve and 5A molecular sieve, with 5A molecular sieve being the most preferred.

[0011] Preferably, the molecular sieve content is 1 to 10 parts by weight, more preferably 5 to 10 parts.

[0012] Preferably, the raw butyl rubber has a Mooney viscosity ML of [missing value]. 1+8 The range is 46 to 56.

[0013] Preferably, the mass ratio of the butyl rubber to the polyisobutylene composition is 1:(0.1-5), more preferably 1:(0.1-3).

[0014] Preferably, the polyisobutylene composition comprises high molecular weight polyisobutylene, medium molecular weight polyisobutylene, and low molecular weight polyisobutylene.

[0015] Preferably, the high molecular weight polyisobutylene has a number average molecular weight of 500,000 to 1,000,000, the medium molecular weight polyisobutylene has a number average molecular weight of 50,000 to 200,000, and the low molecular weight polyisobutylene has a number average molecular weight of 1,000 to 5,000.

[0016] Preferably, the mass ratio of high molecular weight polyisobutylene, medium molecular weight polyisobutylene and low molecular weight polyisobutylene is 1:(1-10):(0.5-2), more preferably 1:(1-8):(0.5-1).

[0017] Preferably, the content of the polyisobutylene composition is 10 to 35 parts by weight, more preferably 15 to 32 parts.

[0018] Preferably, the raw materials for preparing the sealant further include a tackifying resin, which is selected from one or a combination of several of hydrogenated C5 petroleum resin, terpene phenol resin, styrene monomer resin, hydrogenated C9 petroleum resin, and hydrogenated DCPD resin.

[0019] Preferably, the content of the tackifying resin is 1 to 10 parts by weight, more preferably 5 to 10 parts.

[0020] Preferably, the raw materials for preparing the sealant include inorganic fillers, which are selected from one or a combination of several of activated heavy calcium carbonate, heavy calcium carbonate, light calcium carbonate, silica powder, organic bentonite, talc powder, mica powder and quartz powder.

[0021] Preferably, the inorganic filler content is 20-40 parts by weight, and more preferably 20-30 parts by weight.

[0022] Preferably, the raw materials for preparing the sealant further include reinforcing materials, which are selected from one or a combination of carbon black, fumed silica and nano-calcium carbonate; preferably carbon black and / or nano-calcium carbonate.

[0023] Preferably, the reinforcing material contains 10 to 30 parts by weight, and more preferably 10 to 25 parts by weight.

[0024] Preferably, the raw materials for preparing the sealant include: butyl rubber, medium molecular weight polyisobutylene, high molecular weight polyisobutylene, low molecular weight polyisobutylene, silane-modified polyolefin, silane-modified polyisobutylene and / or silane-modified polyether, terpene phenolic resin, carbon black, nano-calcium carbonate, talc, 5A molecular sieve, and antioxidant, wherein the antioxidant is selected from antioxidant 1010 and / or antioxidant 168.

[0025] Preferably, the raw materials for preparing the sealant consist of butyl rubber, medium molecular weight polyisobutylene, high molecular weight polyisobutylene, low molecular weight polyisobutylene, silane-modified polyolefin, silane-modified polyisobutylene, terpene phenolic resin, carbon black, nano-calcium carbonate, talc powder, 5A molecular sieve, and antioxidant, wherein the antioxidant is selected from antioxidant 1010 and / or antioxidant 168.

[0026] Preferably, the raw materials for preparing the sealant include:

[0027]

[0028]

[0029] Preferably, the raw materials for preparing the sealant include:

[0030]

[0031] A second objective of this invention is to provide a method for preparing the sealant according to any one of the above claims, the method comprising the following steps:

[0032] (1) Add the butyl rubber and polyisobutylene composition to the kneader according to the mass percentage, heat up, knead under inert gas protection, and then add reinforcing material, inorganic filler and antioxidant to the kneader and continue kneading.

[0033] (2) Then add the viscous resin, molecular sieve, and silane-modified polymer to the mixture obtained in step (1) according to the mass percentage, turn off the inert gas and draw a vacuum to knead, and control the vacuum degree to 0.08-0.1 MPa.

[0034] Preferably, before step (1), the inorganic filler, reinforcing material, silane-modified polymer, and molecular sieve are first subjected to drying and dehydration treatment.

[0035] Preferably, the kneading temperature in step (1) is controlled to be 110-130°C and the rotation speed is 20 r / min.

[0036] Preferably, the kneading time in step (1) is 25 to 35 minutes, and more preferably 30 minutes.

[0037] Preferably, the kneading temperature in step (2) is 140-160°C and the rotation speed is 30 r / min.

[0038] Preferably, the kneading time in step (2) is 35 to 45 minutes, and more preferably 40 minutes.

[0039] A third objective of this invention is to provide the application of the sealant described in any of the above-mentioned claims or the product obtained according to the preparation method described therein in the field of photovoltaic cells.

[0040] The effects of the invention

[0041] This invention increases the initial tack, adhesive strength, and bulk strength of polymers by compounding polyisobutylene with butyl rubber of different molecular weights. The addition of specially compounded molecular sieves and silane-terminated polymers enables efficient water vapor barrier through a combination of physical and chemical methods. In particular, its application in the edge encapsulation of photovoltaic cells significantly reduces water vapor permeability. Furthermore, the sealant provided by this invention exhibits excellent weather resistance. The sealant preparation method of this invention is carried out under nitrogen protection, with strict control of stirring time to minimize the contact time between the material and water vapor and oxygen. The stirring in the preparation method provided by this invention is a physical mixing process, and no organic waste gas or waste liquid is generated during the preparation and use of the sealant, making it safe, environmentally friendly, and beneficial for industrial production. Detailed Implementation

[0042] To make the technical solution and beneficial effects of the present invention more apparent and understandable, a detailed description is provided below by listing specific embodiments. Unless otherwise defined, the technical and scientific terms used herein have the same meanings as those in the technical field to which this application pertains.

[0043] Butyl sealant is internationally recognized as a polymer material with the best airtightness and watertightness. Therefore, it can be modified based on butyl hot melt adhesive to further optimize its bonding performance and outdoor weather resistance. Existing encapsulation materials have poor water vapor barrier properties, leading to corrosion of internal electronic components due to contact with airborne moisture, resulting in reduced electrical performance and even affecting module lifespan. Through extensive and in-depth research, the inventors discovered that a sealant composed of butyl rubber, a polyisobutylene composition, silane-modified polymers (preferably one or more of silane-modified polyolefins, silane-modified polyethers, and silane-modified polyisobutylene), molecular sieves, reinforcing materials, inorganic fillers, and antioxidants exhibits low water vapor permeability. In particular, when the silane encapsulation polymer is selected from a blend of silane-modified polyolefins and silane-modified polyisobutylene, and 5A molecular sieves are used for molecular sieve selection, the water vapor barrier performance is optimal. Based on this, this invention was completed. The developed polymer material can be used for edge protection of photovoltaic modules.

[0044] As used herein, the term "and / or" refers to any one of the options or any combination of two or more of the options.

[0045] As used herein, the terms "comprising" or "including" mean including the stated elements, integers, or steps, but do not exclude any other elements, integers, or steps. In this invention, when the terms "comprising" or "including" are used, unless otherwise specified, they also cover situations consisting of the stated elements, integers, or steps.

[0046] As used herein, the term "composed of" means excluding any element or combination of elements that would alter the essential and novel features of the invention, and any amount of any element or combination of elements.

[0047] As used herein, the term "butyl rubber" is understood to mean a homopolymer of isobutylene or a copolymer of isobutylene and isoprene (the butyl rubber being included in a diene elastomer), as well as halogenated derivatives of these homopolymers and halogenated derivatives of the copolymer of isobutylene and isoprene, particularly, said halogenated derivatives are typically brominated or chlorinated derivatives. Examples include isobutylene rubber, copolymers of isobutylene and isoprene (IIR), brominated butyl rubber, such as brominated isobutylene / isoprene copolymer (BIIR), chlorinated butyl rubber, such as chlorinated isobutylene / isoprene copolymer (CIIR), and mixtures thereof.

[0048] As used in this article, "silane-modified olefin polymer" refers to a novel olefin copolymer that is modified with silane after being an amorphous poly-α-olefin copolymer polymerized by the Ziegler method. It can be APAO series products such as APAO206.

[0049] As used herein, the term "filler" refers to any material used to enhance or alter physical properties, impart certain processing properties, or reduce the cost of an elastomer composition.

[0050] As used in this article, an "antioxidant" is a substance that, when present in small amounts in a polymer system, can delay or inhibit the polymer oxidation process, thereby preventing polymer aging and extending its service life.

[0051] The first objective of this invention is to provide a sealant, the raw materials for which the sealant is prepared include the following components: butyl rubber, polyisobutylene composition, silane-modified polymer, and molecular sieve, wherein the silane-modified polymer is selected from one or a combination of several of silane-modified polyolefins, silane-modified polyethers, and silane-modified polyisobutylene.

[0052] In some embodiments, the silane-modified polymer is selected from a combination of silane-modified polyolefins and silane-modified polyisobutylene.

[0053] In some embodiments, the mass ratio of the silane-modified polyolefin to the silane-modified polyisobutylene is 1:(0.1-2), for example 1:0.1, 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1, 1:1.5, etc.

[0054] In some embodiments, the mass ratio of the silane-modified polyolefin to the silane-modified polyisobutylene is 1:(0.1-1).

[0055] In some embodiments, the silane-modified polymer is selected from a combination of silane-modified polyolefins and silane-modified polyethers.

[0056] In some embodiments, the mass ratio of the silane-modified polyolefin to the silane-modified polyether is 1:(0.1-2), for example 1:0.1, 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1, 1:1.5, etc.

[0057] In some embodiments, the mass ratio of the silane-modified polyolefin to the silane-modified polyether is 1:(0.1 to 1).

[0058] In some embodiments, the content of the silane-modified polymer is 5 to 20 parts by weight, for example, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, etc.

[0059] In some embodiments, the content of the silane-modified polymer is 8 to 15 parts.

[0060] In some embodiments, the molecular sieve is selected from one or a combination of 3A molecular sieve, 4A molecular sieve and 5A molecular sieve.

[0061] In some embodiments, the molecular sieve is selected from 5A molecular sieve.

[0062] In some embodiments, the molecular sieve content is 1 to 10 parts by weight, for example, 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, etc.

[0063] In some embodiments, the content of the molecular sieve is 5 to 10 parts by weight.

[0064] In some embodiments, the raw butyl rubber has a Mooney viscosity ML1+8 of 46 to 56.

[0065] In some embodiments, the mass ratio of the butyl rubber to the polyisobutylene composition is 1:(0.1-5), for example 1:0.2, 1:0.4, 1:0.6, 1:0.8, 1:1, 1:1.2, 1:1.4, 1:1.6, 1:1.8, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, etc.

[0066] In some embodiments, the mass ratio of the butyl rubber to the polyisobutylene composition is 1:(0.1-3).

[0067] In some embodiments, the polyisobutylene composition includes high molecular weight polyisobutylene, medium molecular weight polyisobutylene, and low molecular weight polyisobutylene.

[0068] In some embodiments, the high molecular weight polyisobutylene has a number average molecular weight of 500,000 to 1,000,000, the medium molecular weight polyisobutylene has a number average molecular weight of 50,000 to 200,000, and the low molecular weight polyisobutylene has a number average molecular weight of 1,000 to 5,000.

[0069] In some embodiments, the mass ratio of high molecular weight polyisobutylene, medium molecular weight polyisobutylene, and low molecular weight polyisobutylene is 1:(1-10):(0.5-2), for example 1:2:0.5, 1:3:0.5, 1:4:0.5, 1:4:0.5, 1:4:0.6, 1:4:1, 1:4:1.5, 1:2:1, 1:2:1.5, 1:1:1, 1:3.5:1, 1:3.5:1, etc.

[0070] In some embodiments, the mass ratio of the high molecular weight polyisobutylene, the medium molecular weight polyisobutylene, and the low molecular weight polyisobutylene is 1:(1-8):(0.5-1).

[0071] In some embodiments, the content of the polyisobutylene composition is 10 to 35 parts by weight, for example 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, etc.

[0072] In some embodiments, the content of the polyisobutylene composition is 15 to 32 parts by weight.

[0073] In some embodiments, the raw materials for preparing the sealant further include a tackifying resin, which is selected from one or a combination of several of hydrogenated C5 petroleum resin, terpene phenol resin, styrene monomer resin, hydrogenated C9 petroleum resin, and hydrogenated DCPD resin.

[0074] In some embodiments, the tackifying resin is selected from terpene phenol resins and / or hydrogenated DCPD resins.

[0075] In some embodiments, the content of the tackifying resin is 1 to 10 parts by weight, for example, 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, etc.

[0076] In some embodiments, the content of the tackifying resin is 5 to 10 parts by weight.

[0077] In some embodiments, the raw materials for preparing the sealant include inorganic fillers selected from one or more of activated heavy calcium carbonate, heavy calcium carbonate, light calcium carbonate, silica powder, organobentonite, talc powder, mica powder, and quartz powder.

[0078] In some embodiments, the inorganic filler is selected from one or a combination of several of organic bentonite, talc, heavy calcium carbonate, and light calcium carbonate.

[0079] In some embodiments, the inorganic filler is selected from organic bentonite and / or talc.

[0080] In some embodiments, the content of the inorganic filler is 20 to 40 parts by weight, for example, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40 parts, etc.

[0081] In some embodiments, the content of the inorganic filler is 20 to 30 parts by weight.

[0082] In some embodiments, the raw materials for preparing the sealant also include reinforcing materials selected from one or more of carbon black, fumed silica, and nano-calcium carbonate.

[0083] In some embodiments, the reinforcing material is carbon black and / or nano-calcium carbonate.

[0084] In some embodiments, the content of the reinforcing material is 10 to 30 parts by weight, for example 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, etc.

[0085] In some embodiments, the reinforcing material is present in a content of 10 to 25 parts by weight.

[0086] In some embodiments, the raw materials for preparing the sealant include: butyl rubber, medium molecular weight polyisobutylene, high molecular weight polyisobutylene, low molecular weight polyisobutylene, silane-modified polyolefin, silane-modified polyisobutylene and / or silane-modified polyether, terpene phenolic resin, carbon black, nano-calcium carbonate, talc, 5A molecular sieve, and antioxidant, wherein the antioxidant is selected from antioxidant 1010 and / or antioxidant 168.

[0087] In some embodiments, the raw materials for preparing the sealant consist of butyl rubber, medium molecular weight polyisobutylene, high molecular weight polyisobutylene, low molecular weight polyisobutylene, silane-modified polyolefin, silane-modified polyisobutylene, terpene phenolic resin, carbon black, nano-calcium carbonate, talc, 5A molecular sieve, and antioxidant, wherein the antioxidant is selected from antioxidant 1010 and / or antioxidant 168.

[0088] In some embodiments, the raw materials for preparing the sealant include: butyl rubber, medium molecular weight polyisobutylene, high molecular weight polyisobutylene, low molecular weight polyisobutylene, silane-modified polyolefin, silane-modified polyether, terpene phenolic resin, carbon black, nano-calcium carbonate, talc, 5A molecular sieve, and antioxidant, wherein the antioxidant is selected from antioxidant 1010 and / or antioxidant 168.

[0089] In some embodiments, the raw materials for preparing the sealant include:

[0090]

[0091]

[0092] In some embodiments, the raw materials for preparing the sealant include:

[0093]

[0094] In some embodiments, the raw materials for preparing the sealant include:

[0095]

[0096]

[0097] A second objective of this invention is to provide a method for preparing the sealant according to any one of the above claims, the method comprising the following steps:

[0098] (1) Add the butyl rubber and polyisobutylene composition to the kneader according to the mass percentage, heat up, knead under inert gas protection, and then add reinforcing material, inorganic filler and antioxidant to the kneader and continue kneading.

[0099] (2) Then add the viscous resin, molecular sieve, and silane-modified polymer to the mixture obtained in step (1) according to the mass percentage, turn off the inert gas and draw a vacuum to knead, and control the vacuum degree to 0.08-0.1 MPa.

[0100] In some embodiments, the inorganic filler, reinforcing material, silane-modified polymer, and molecular sieve are first dried and dehydrated before step (1). The preparation method provided by this invention can significantly reduce the contact between each component and water and oxygen.

[0101] In some embodiments, the kneading temperature in step (1) is controlled to be 110–130°C and the rotation speed is 20 r / min.

[0102] In some embodiments, the kneading time in step (1) is 25 to 35 minutes, preferably 30 minutes.

[0103] In some embodiments, the kneading temperature in step (2) is controlled to be 140–160°C and the rotation speed is 30 r / min.

[0104] In some embodiments, the kneading time in step (2) is 35 to 45 minutes, preferably 40 minutes.

[0105] A third objective of this invention is to provide the application of the sealant described in any of the above claims or the product obtained according to the preparation method described above in the field of photovoltaic cells.

[0106] The present invention will be further described below with reference to specific embodiments and comparative examples. Unless otherwise specified, specific techniques or conditions in the following embodiments are generally performed according to conventional techniques or conditions described in the literature in the art, or according to the product instructions and the manufacturer's recommendations. Unless otherwise specified, all starting materials, materials, and reagents are commercially available or synthesized according to known methods.

[0107] The sources of the materials used in this invention are shown in the table below:

[0108]

[0109]

[0110] Example 1

[0111] Please refer to the table below for specific selection of each raw material:

[0112] Butyl rubber 10 Medium molecular weight polyisobutylene 20 Macromolecular polyisobutylene 5 Small molecule polyisobutylene 3 Terpene phenol resin 8 carbon black 10 Organic bentonite 23 Nano calcium carbonate 20 Antioxidant 1010 0.5 Antioxidant 168 0.5 total 100

[0113] Example 2

[0114] Except for the different raw material composition, it is basically the same as Example 1. For the specific selection of each raw material, please refer to the table below:

[0115] Butyl rubber 10 Medium molecular weight polyisobutylene 28 Terpene phenol resin 8 carbon black 10 Organic bentonite 23 Nano calcium carbonate 20 Antioxidant 1010 0.5 Antioxidant 168 0.5 total 100

[0116] Example 3

[0117] Except for the different raw material composition, it is basically the same as Example 1. For the specific selection of each raw material, please refer to the table below:

[0118]

[0119]

[0120] Example 4

[0121] Except for the different raw material composition, it is basically the same as Example 1. For the specific selection of each raw material, please refer to the table below:

[0122] Butyl rubber 10 Medium molecular weight polyisobutylene 12 Macromolecular polyisobutylene 4 Small molecule butyl rubber 2 Terpene phenol resin 8 Silane-modified polyolefins 8 Silane-modified polyisobutylene 5 carbon black 5 talcum powder 20 5A molecular sieve 5 Nano calcium carbonate 20 Antioxidant 1010 0.5 Antioxidant 168 0.5 total 100

[0123] Example 5

[0124] Except for the different raw material composition, it is basically the same as Example 1. For the specific selection of each raw material, please refer to the table below:

[0125] Butyl rubber 10 Medium molecular weight polyisobutylene 12 Macromolecular polyisobutylene 4 Small molecule butyl rubber 2 Terpene phenol resin 8 Silane-modified polyolefins 8 Silane-modified polyether 5 carbon black 5 talcum powder 25 Nano calcium carbonate 20 Antioxidant 1010 0.5 Antioxidant 168 0.5 total 100

[0126] Example 6

[0127] Except for the different raw material composition, it is basically the same as Example 1. For the specific selection of each raw material, please refer to the table below:

[0128]

[0129]

[0130] Example 7

[0131] Except for the different raw material composition, it is basically the same as Example 1. For the specific selection of each raw material, please refer to the table below:

[0132] Butyl rubber 10 Medium molecular weight polyisobutylene 20 Macromolecular polyisobutylene 6 Small molecule polyisobutylene 6 carbon black 10 Organic bentonite 25 Nano calcium carbonate 22 Antioxidant 1010 0.5 Antioxidant 168 0.5 total 100

[0133] Example 8

[0134] Except for the different raw material composition, it is basically the same as Example 1. For the specific selection of each raw material, please refer to the table below:

[0135] Butyl rubber 10 Medium molecular weight polyisobutylene 20 Macromolecular polyisobutylene 5 Small molecule polyisobutylene 3 carbon black 10 Dcpd resin 8 Organic bentonite 23 Nano calcium carbonate 20 Antioxidant 1010 0.5 Antioxidant 168 0.5 total 100

[0136] Example 9

[0137] Except for the different raw material composition, it is basically the same as Example 1. For the specific selection of each raw material, please refer to the table below:

[0138] Butyl rubber 20 Medium molecular weight polyisobutylene 5 Macromolecular polyisobutylene 5 Small molecule polyisobutylene 5 Silane-modified polyolefins 10 Terpene phenol resin 5 talcum powder 21 carbon black 10 Light calcium 18 Antioxidant 1010 0.5 Antioxidant 168 0.5 total 100

[0139] Example 10

[0140] Except for the different raw material composition, it is basically the same as Example 1. For the specific selection of each raw material, please refer to the table below:

[0141] Butyl rubber 21 Medium molecular weight polyisobutylene 10 Macromolecular polyisobutylene 5 Small molecule polyisobutylene 3 Terpene phenol resin 8 Organic bentonite 26 Nano calcium carbonate 26 Antioxidant 1010 0.5 Antioxidant 168 0.5 total 100

[0142] Example 11

[0143] Except for the different raw material composition, it is basically the same as Example 1. For the specific selection of each raw material, please refer to the table below:

[0144] Butyl rubber 21 Medium molecular weight polyisobutylene 10 Macromolecular polyisobutylene 5 Small molecule polyisobutylene 3 Terpene phenol resin 8 carbon black 5 Fumed silica 1 Nano calcium carbonate 4 Organic bentonite 22 Trihydrate 20 Antioxidant 1010 0.5 Antioxidant 168 0.5 total 100

[0145] Example 12

[0146] Except for the different raw material composition, it is basically the same as Example 1. For the specific selection of each raw material, please refer to the table below:

[0147] Butyl rubber 10 Medium molecular weight polyisobutylene 12 Macromolecular polyisobutylene 4 Small molecule butyl rubber 2 Terpene phenol resin 8 Silane-modified polyolefins 8 Silane-modified polyisobutylene 5 carbon black 5 talcum powder 23 Nano calcium carbonate 22 Antioxidant 1010 0.5 Antioxidant 168 0.5 total 100

[0148] Example 13

[0149] Except for the different raw material composition, it is basically the same as Example 1. For the specific selection of each raw material, please refer to the table below:

[0150]

[0151]

[0152] Comparative Example 1:

[0153] Except for the different raw material composition, it is basically the same as Example 1. For the specific selection of each raw material, please refer to the table below:

[0154] Butyl rubber 45 carbon black 10 Tackifying resin 20 Trihydrate 10 Organic bentonite 15 total 100

[0155] Comparative Example 2: Commercially available silicone sealant - Loctite RTV5900.

[0156] Comparative Example 3: Commercially available butyl sealant - Kangda New Materials WD216.

[0157] Performance testing

[0158] 1. UV resistance test: To verify the UV resistance of the sealant, the UV resistance test was conducted in accordance with the UV pretreatment section of IEC61345.

[0159] 2. Determination of tensile shear strength of glass: The tensile shear strength of the sealant was tested according to the test method of national standard GB / T 7124-2008.

[0160] 3. Determination of water vapor transmission rate: The water vapor transmission rate of the sealant was tested according to the test method of GB / T 21529-2008.

[0161] The test results are shown in the table below:

[0162]

[0163]

[0164] As can be seen from the table above, the sealant provided in this invention, by adding different components and adjusting the weight ratio of each component, produces a synergistic effect, ensuring low water vapor permeability, weather resistance and bonding strength, and can effectively meet the requirements for blocking water vapor outdoors for a long time.

[0165] It should be understood that the above embodiments are exemplary and are not intended to encompass all possible implementations included in the claims. Various modifications and changes can be made to the above embodiments without departing from the scope of this disclosure. Similarly, the various technical features of the above embodiments can be arbitrarily combined to form other embodiments of the present invention that may not be explicitly described. Therefore, the above embodiments only illustrate several implementations of the present invention and do not limit the scope of protection of this patent.

Claims

1. A sealant, characterized in that, The raw materials for preparing the sealant consist of the following components: ； The high molecular weight polyisobutylene has a number average molecular weight of 500,000 to 1,000,000, the medium molecular weight polyisobutylene has a number average molecular weight of 50,000 to 200,000, and the low molecular weight polyisobutylene has a number average molecular weight of 1,000 to 5,000.

2. A sealant, characterized in that, The raw materials for preparing the sealant consist of the following components: ； The high molecular weight polyisobutylene has a number average molecular weight of 500,000 to 1,000,000, the medium molecular weight polyisobutylene has a number average molecular weight of 50,000 to 200,000, and the low molecular weight polyisobutylene has a number average molecular weight of 1,000 to 5,000.

3. A method for preparing the sealant according to any one of claims 1 to 2, characterized in that, The preparation method includes the following steps: (1) Add the butyl rubber and polyisobutylene composition to the kneader according to the mass percentage, heat up, knead under inert gas protection, and then add reinforcing material, inorganic filler and antioxidant to the kneader and continue kneading; (2) Then add the viscous resin, molecular sieve, and silane-modified polymer to the mixture obtained in step (1) according to the mass percentage, turn off the inert gas and draw a vacuum to knead, and control the vacuum degree to 0.08~0.1MPa; The reinforcing materials are carbon black and nano-calcium carbonate; the inorganic filler is talc.

4. The application of the sealant according to any one of claims 1 to 2 or the product obtained by the preparation method according to claim 3 in the field of photovoltaic cells.

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