Modified butyl rubber, self-healing butyl hot melt adhesive for photovoltaic modules and its preparation method

Abstract

This invention relates to a modified butyl rubber, a self-healing butyl hot melt adhesive for photovoltaic modules, and a method for preparing the same. The modified butyl rubber is obtained by reacting halogenated butyl rubber sequentially with a hydroxyl acrylate compound and a hydrogen-containing silane; the hydroxyl acrylate compound has the structural formula HO(CH2). m CH=CHCOOH, where m is selected from: 2, 3, 4, 5, 6, 7, 8; the structural formula of the hydrogen-containing silane is HSi(R1)(OR2)2, where R1 is selected from: C1~C6 alkoxy, C1~C6 alkyl, and R2 is selected from: C1~C6 alkyl. The self-healing butyl hot melt adhesive for photovoltaic modules is prepared from the modified butyl rubber and other raw materials. The butyl hot melt adhesive of the present invention has good adhesion to the glass interface, high strength, good mechanical properties, high water vapor barrier rate, and excellent self-healing properties, and can be used in the field of photovoltaic modules.

Description

Technical Field

[0001] This invention belongs to the field of sealant technology, specifically relating to a modified butyl rubber, a self-healing butyl hot melt adhesive for photovoltaic modules, and its preparation method. Background Technology

[0002] Butyl rubber's regular molecular structure endows it with excellent air tightness and very low water vapor permeability, making it widely used in the airtight layer of tire inner tubes, the first seal of insulated glass, building waterproof membranes, special waterproof tapes, and photovoltaic modules.

[0003] Butyl hot melt adhesive is a single-component, solvent-free, non-fogging, and non-vulcanizing thermoplastic material based on butyl rubber and polyisobutylene. In the photovoltaic module field, especially in perovskite and heterojunction photovoltaic modules sensitive to moisture, it is used as the first line of defense against water vapor, serving as an edge sealant. The dense arrangement of side methyl groups in the butyl rubber molecular chain restricts the thermal motion of polymer molecules, reduces chain flexibility, and produces micro-crystals. These structural characteristics give butyl rubber excellent weather resistance, heat resistance, and alkali resistance, low water vapor permeability, and good air tightness; its air permeability is an order of magnitude lower than that of natural rubber. However, the adhesion between butyl rubber and the glass interface is still not ideal. Adhesion tends to decrease after aging, and problems such as insufficient adhesive and delamination occur after aging under ultraviolet light, humidity, and high / low temperatures. It also exhibits poor water vapor barrier properties, failing to guarantee a long-lasting water vapor barrier effect during use.

[0004] Furthermore, improper application or errors during sealant use can easily lead to damage, defects, or bubbles in the sealant, causing a decline in its mechanical properties and, in severe cases, even sealing failure, significantly reducing the lifespan of photovoltaic modules. Moreover, butyl hot melt sealant itself lacks the ability to repair damage, which greatly reduces the product qualification rate as an edge sealing system. Summary of the Invention

[0005] Based on this, the purpose of the present invention is to provide a self-healing butyl hot melt adhesive for photovoltaic modules with good bonding effect.

[0006] The technical solutions for achieving the above objectives include the following.

[0007] The first aspect of the present invention is to provide a modified butyl rubber, which is obtained by reacting halogenated butyl rubber sequentially with a hydroxyl acrylate compound and a hydrogen-containing silane;

[0008] The structural formula of the hydroxyolefin compound is HO(CH2). m CH=CHCOOH, where m is selected from: 2, 3, 4, 5, 6, 7, 8;

[0009] The structural formula of the hydrogen-containing silane is HSi(R1)(OR2)2, wherein R1 is selected from C1-C6 alkoxy or C1-C6 alkyl, and R2 is selected from C1-C6 alkyl.

[0010] In some embodiments, the halogenated butyl rubber is brominated butyl rubber and / or chlorinated butyl rubber.

[0011] In some embodiments, the raw Mooney viscosity ML of the halogenated butyl rubber is... 1+8 The value is 27-50, preferably 30-40.

[0012] In some embodiments, the halogenated butyl rubber contains 1 to 2.2% halogen groups by mass.

[0013] In some embodiments, R1 is selected from: -OCH3, -OCH2CH3, -CH3, -CH2CH3, and R2 is -CH3 or -CH2CH3.

[0014] In some embodiments, the molar ratio of halogen groups, hydroxyl olefin compounds and hydrogen-containing silanes in the halogenated butyl rubber is 1:0.8-3:0.8-3, preferably 1:0.9-1.1:0.9-1.1.

[0015] A second aspect of the present invention is to provide a method for preparing the modified butyl rubber, comprising the following steps:

[0016] (1) The halobutyl rubber and hydroxyolefin compounds are reacted in an organic solvent under the action of an inorganic base to obtain an intermediate product;

[0017] (2) The intermediate product and the hydrogen-containing silane are reacted in an organic solvent under the action of a platinum catalyst to obtain the modified butyl rubber.

[0018] In some of these embodiments, the organic solvent in step (1) is tetrahydrofuran.

[0019] In some embodiments, the inorganic base in step (1) is potassium carbonate.

[0020] In some embodiments, the molar ratio of the halogen groups of the halogenated butyl rubber to potassium carbonate is 1:1 to 2.

[0021] In some embodiments, the temperature of the reaction in step (1) is 15°C to 35°C, and the reaction time is 10 hours to 20 hours.

[0022] In some embodiments, the platinum catalyst in step (2) is chloroplatinic acid or a cassiterite catalyst.

[0023] In some embodiments, the mass ratio of the hydrogen-containing silane to the platinum catalyst is 1:0.02% to 0.08%.

[0024] In some embodiments, the organic solvent in step (2) is toluene.

[0025] In some embodiments, the reaction in step (2) includes reacting at a temperature of 60°C to 90°C for 2 to 8 hours, and then raising the temperature to 70°C to 100°C to continue the reaction for 3 to 9 hours.

[0026] In some embodiments, the reaction in step (2) includes reacting at a temperature of 65°C to 75°C for 3 to 6 hours, and then raising the temperature to 90°C to 100°C to continue the reaction for 5 to 7 hours.

[0027] In some embodiments, the method for preparing the modified butyl rubber includes the following steps:

[0028] The halogenated butyl rubber is dissolved in tetrahydrofuran, and then the hydroxyl olefin compound and inorganic base are added to the solution. The mixture is stirred at 15°C to 35°C for 10 to 20 hours. After removing the solid, the tetrahydrofuran is removed. The resulting intermediate product is dissolved in toluene, and the hydrogen-containing silane and platinum catalyst are added. The temperature is raised to 60°C to 90°C, and the reaction is carried out for 2 to 8 hours. Then the temperature is raised to 70°C to 100°C, and the reaction is continued for 3 to 9 hours. Finally, the temperature inside the reactor is raised to 110°C to 130°C, and the solvent is removed by vacuum to obtain the modified butyl rubber.

[0029] A third aspect of the present invention is to provide a self-healing butyl hot melt adhesive for photovoltaic modules, wherein the raw materials for its preparation include the modified butyl rubber described in the present invention.

[0030] In some embodiments, the self-healing butyl hot melt adhesive for photovoltaic modules is prepared from raw materials comprising the following components, by weight:

[0031]

[0032]

[0033] In some embodiments, the self-healing butyl hot melt adhesive for photovoltaic modules is prepared from raw materials comprising the following components, by weight:

[0034]

[0035] In some embodiments, the self-healing butyl hot melt adhesive for photovoltaic modules is prepared from raw materials comprising the following components, by weight:

[0036]

[0037]

[0038] In some embodiments, the polyisobutylene is composed of two or three of low molecular weight polyisobutylene, medium molecular weight polyisobutylene, and high molecular weight polyisobutylene; the low molecular weight polyisobutylene has a viscosity-average molecular weight of 400 to 30,000, the medium molecular weight polyisobutylene has a viscosity-average molecular weight of 30,000 to 100,000, and the high molecular weight polyisobutylene has a viscosity-average molecular weight of 100,000 to 2,000,000.

[0039] In some embodiments, the polyisobutylene is composed of medium molecular weight polyisobutylene and high molecular weight polyisobutylene; the medium molecular weight polyisobutylene has a viscosity-average molecular weight of 60,000 to 95,000; and the high molecular weight polyisobutylene has a viscosity-average molecular weight of 200,000 to 500,000.

[0040] In some embodiments, the polyisobutylene is composed of medium molecular weight polyisobutylene and high molecular weight polyisobutylene in a mass ratio of 1:0.5-1.5.

[0041] In some embodiments, the metal salt is an iron salt and / or a zinc salt.

[0042] In some embodiments, the metal salt is zinc chloride and / or ferric chloride.

[0043] In some embodiments, the plasticizer is one or more of polybutene, phthalate, dioctyl adipate and diisooctyl adipate.

[0044] In some embodiments, the tackifying resin is selected from one or more combinations of C5 petroleum resin, C9 petroleum resin, terpene resin, styrene-grafted terpene resin, polyterpene resin, natural resin and rosin resin.

[0045] In some embodiments, the absorbent is selected from one or more combinations of calcium oxide, molecular sieve, calcium sulfate, anhydrous calcium chloride, anhydrous magnesium sulfate, and activated alumina.

[0046] In some embodiments, the inorganic filler is selected from one or more combinations of mica powder, silica powder, kaolin, calcium carbonate, talc, kaolin, clay, and diatomaceous earth.

[0047] In some embodiments, the reinforcing agent is selected from one or a combination of two of carbon black and fumed silica.

[0048] In some embodiments, the antioxidant is selected from one or more combinations of pentaerythritol tetrakis[2-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 2,6-di-tert-butyl-4-methylphenol, tris[2,4-di-tert-butylphenyl]phosphite, 2-methyl-4,6-dinonylphenol, 2,6-di-tert-butyl-α-methoxy-p-cresol, 2,4,6-tri-tert-butylphenol, and 2,2,4-trimethyl-1,2-dihydroquinoline polymer.

[0049] In some embodiments, the light stabilizer is selected from one or more combinations of hindered amine light stabilizers.

[0050] In some embodiments, the light stabilizer is selected from 2'-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole and / or 2-[2-hydroxy-5-tert-octylphenyl)benzotriazole.

[0051] A fourth aspect of the present invention is to provide a method for preparing a self-healing butyl hot melt adhesive for photovoltaic modules, comprising the following steps:

[0052] At 110℃~160℃, the modified butyl rubber, polyisobutylene, plasticizer, tackifying resin and antioxidant are added sequentially to a kneader and mixed under vacuum for 20 minutes to 130 minutes; then the inorganic filler, reinforcing agent, water absorbent, light stabilizer and metal salt are added sequentially and mixed under vacuum for 60 minutes to 180 minutes to obtain the self-healing butyl hot melt adhesive for photovoltaic modules.

[0053] In some embodiments, the method for preparing the self-healing butyl hot melt adhesive for photovoltaic modules includes the following steps:

[0054] At 140℃~160℃, the modified butyl rubber, polyisobutylene, plasticizer, tackifying resin and antioxidant are added sequentially to a kneader and mixed under vacuum for 20 minutes to 40 minutes; then the inorganic filler, reinforcing agent, water absorbent, light stabilizer and metal salt are added sequentially and mixed under vacuum for 100 minutes to 150 minutes to obtain the self-healing butyl hot melt adhesive for photovoltaic modules.

[0055] The present invention has the following beneficial effects:

[0056] This invention modifies halogenated butyl rubber with hydroxyl acrylic compounds and hydrogen-containing silanes to obtain modified butyl rubber with siloxane and carboxyl groups. This modified butyl rubber, combined with polyisobutylene, metal salts, and other components, is then formulated into a reactive butyl hot melt adhesive with self-healing properties. In this butyl hot melt adhesive system, the siloxane groups serve two purposes: firstly, they facilitate the formation of a first chemical cross-linking network through a de-alcoholization reaction after application; secondly, they improve the adhesion between the butyl hot melt adhesive and glass. The carboxyl groups coordinate with the metal salt to form a second cross-linking network, enhancing the material's mechanical properties while also imparting excellent self-healing properties to the butyl hot melt adhesive. With the synergistic effect of the components, the butyl hot melt adhesive of this invention exhibits excellent adhesion to the glass interface, high strength, good mechanical properties, high water vapor barrier properties, and superior self-healing performance, making it suitable for use in photovoltaic modules. Furthermore, the electrostatic interactions within the system undergo reversible dissociation at higher temperatures without affecting the processing and application performance of the butyl hot melt adhesive. Detailed Implementation

[0057] To facilitate understanding of the present invention, a more complete description will be provided below. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the present invention.

[0058] Unless otherwise specified, experimental methods in the following examples are generally performed under standard conditions or as recommended by the manufacturer. All raw materials and chemical reagents used in the examples are commercially available products.

[0059] Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. The term "and / or" as used in this invention includes any and all combinations of one or more of the associated listed items.

[0060] Furthermore, as used herein, the term "or" is an inclusive "or" sign and is equivalent to the term "and / or" unless the context clearly specifies otherwise. The term "based on" is not exclusive and allows for basing on other factors not described unless the context clearly specifies otherwise. Additionally, throughout the specification, the meanings of "an," "a," and "the" include plural indicators. The meaning of "in" includes both "in" and "on."

[0061] The present invention will be further described in detail below with reference to specific embodiments.

[0062] In the following embodiments, the normal temperature or room temperature refers to an indoor temperature of 20℃-30℃.

[0063] Example 1

[0064] 300g of brominated butyl rubber (raw rubber Mooney viscosity ML) 1+8 =33, bromine content 1.9wt%, bromine molar amount 0.071mol, commercially available) was dissolved in 2L of tetrahydrofuran, and then 13.3g of HO(CH2)7CH=CHCOOH (0.071mol, commercially available) and 9.8g of potassium carbonate (0.071mol, commercially available) were added to the solution. After stirring at room temperature for 12 hours, the solid was filtered and the tetrahydrofuran was removed by rotary evaporation. The obtained product was dissolved in 300mL of toluene, and 8.7g of HSi(OCH3)3 (0.071mol, commercially available) and 4.4mg of chloroplatinic acid (0.05% of the mass of the hydrogen-containing silane, commercially available) were added. The temperature was raised to 70℃ and reacted for 6 hours, and then the temperature was raised to 100℃ and the reaction was continued for 7 hours. Finally, the temperature in the reactor was raised to 110℃ and the solvent was removed by vacuum to obtain the modified butyl rubber.

[0065] At 150°C, the modified butyl rubber, polyisobutylene mixture, plasticizer, tackifying resin and antioxidant shown in Table 1 were added sequentially to a kneader and mixed for 30 minutes under vacuum protection of -0.1MPa; then the inorganic filler, reinforcing agent, water absorbent, light stabilizer and metal salt shown in Table 1 were added sequentially and mixed thoroughly for 120 minutes under vacuum protection of -0.1MPa to obtain a self-healing butyl hot melt adhesive for photovoltaic modules.

[0066] Table 1

[0067]

[0068]

[0069] Example 2

[0070] 300g of chlorinated butyl rubber (raw rubber Mooney viscosity ML) 1+8=38, chlorine content 1.26wt%, chlorine molar amount 0.1mol, commercially available) was dissolved in 2L of tetrahydrofuran, and then 18.6g of HO(CH2)7CH=CHCOOH (0.1mol, commercially available) and 13.8g (0.1mol, commercially available) potassium carbonate were added to the solution. After stirring at room temperature for 18 hours, the solid was filtered and the tetrahydrofuran was removed by rotary evaporation. The obtained product was dissolved in 300mL of toluene, and 16.4g of HSi(OCH2CH3)3 (0.1mol, commercially available) and 8.5mg (0.05% of the mass of the hydrogen-containing silane, commercially available) chloroplatinic acid were added. The temperature was raised to 70℃ and reacted for 3 hours, and then the temperature was raised to 100℃ and the reaction was continued for 7 hours. Finally, the temperature in the reaction vessel was raised to 110℃ and the solvent was removed by vacuum to obtain the modified butyl rubber.

[0071] At 170°C, modified butyl rubber, polyisobutylene mixture, plasticizer, tackifying resin and antioxidant were added to the kneader in sequence according to Table 2, and mixed for 30 minutes under -0.1MPa vacuum protection; then inorganic filler, reinforcing agent, water absorbent, light stabilizer and metal salt were added in sequence, and mixed thoroughly for 120 minutes under -0.1MPa vacuum protection to obtain self-healing butyl hot melt adhesive for photovoltaic modules.

[0072] Table 2

[0073]

[0074]

[0075] Example 3

[0076] 300g of brominated butyl rubber (raw rubber Mooney viscosity ML) 1+8 =33, bromine content 1.9wt%, bromine molar amount 0.071mol, commercially available) was dissolved in 2L of tetrahydrofuran, and then 8.2g of HO(CH2)2CH=CHCOOH (0.071mol, commercially available) and 9.8g (0.071mol, commercially available) potassium carbonate were added to the solution. After stirring at room temperature for 18 hours, the solid was filtered and the tetrahydrofuran was removed by rotary evaporation. The obtained product was dissolved in 300mL of toluene, and 11.6g of HSi(OCH2CH3)3 (0.071mol, commercially available) and 5.8mg of caster catalyst (mass of 0.05% of the mass of the hydrogen-containing silane, commercially available) were added. The temperature was raised to 70℃ and reacted for 3 hours, then the temperature was raised to 90℃ and the reaction was continued for 5 hours. Finally, the temperature in the reactor was raised to 110℃ and the solvent was removed by vacuum to obtain the modified butyl rubber.

[0077] At 160℃, modified butyl rubber, polyisobutylene mixture, plasticizer, tackifying resin and antioxidant were added to the kneader in sequence according to Table 3, and mixed for 60 minutes under -0.1MPa vacuum protection; then inorganic filler, reinforcing agent, water absorbent, light stabilizer and metal salt were added in sequence, and mixed thoroughly for 120 minutes under -0.1MPa vacuum protection to obtain self-healing butyl hot melt adhesive for photovoltaic modules.

[0078] Table 3

[0079]

[0080] Example 4

[0081] 300g of brominated butyl rubber (raw rubber Mooney viscosity ML) 1+8 =33, bromine content 1.9wt%, bromine molar amount 0.071mol, commercially available) was dissolved in 2L of tetrahydrofuran, and then 13.3g of HO(CH2)7CH=CHCOOH (0.071mol, commercially available) and 9.8g of potassium carbonate (0.071mol, commercially available) were added to the solution. After stirring at room temperature for 18 hours, the solid was filtered and the tetrahydrofuran was removed by rotary evaporation. The obtained product was dissolved in 300mL of toluene, and 7.6g of HSi(CH3)(OCH3)2 (0.071mol, commercially available) and 3.8mg of caster catalyst (0.05% of the mass of the hydrogen-containing silane, commercially available) were added. The temperature was raised to 70℃ and reacted for 4 hours, and then the temperature was raised to 90℃ and the reaction was continued for 5 hours. Finally, the temperature in the reactor was raised to 110℃ and the solvent was removed by vacuum to obtain the modified butyl rubber.

[0082] At 160℃, the modified butyl rubber, polyisobutylene mixture, plasticizer, tackifying resin and antioxidant were added to the kneader in sequence according to Table 4, and mixed for 45 minutes under -0.1MPa vacuum protection; then the inorganic filler, reinforcing agent, water absorbent, light stabilizer and metal salt were added in sequence, and mixed thoroughly for 120 minutes under -0.1MPa vacuum protection to obtain the self-healing butyl hot melt adhesive for photovoltaic modules.

[0083] Table 4

[0084]

[0085] Example 5

[0086] 300g of brominated butyl rubber (raw rubber Mooney viscosity ML) 1+8=33, bromine content 1.9wt%, bromine molar amount 0.071mol, commercially available) was dissolved in 2L of tetrahydrofuran, and then 8.2g of HO(CH2)2CH=CHCOOH (0.071mol, commercially available) and 9.8g of potassium carbonate (0.071mol, commercially available) were added to the solution. After stirring at room temperature for 18 hours, the solid was filtered and the tetrahydrofuran was removed by rotary evaporation. The obtained product was dissolved in 300mL of toluene, and 9.6g of HSi(CH3)(OCH2CH3)2 (0.071mol, commercially available) and 4.8mg of caster catalyst (mass of 0.05% of the mass of the hydrogen-containing silane) were added. The temperature was raised to 70℃ and reacted for 5 hours, and then the temperature was raised to 90℃ and the reaction was continued for 5 hours. Finally, the temperature in the reactor was raised to 110℃ and the solvent was removed by vacuum to obtain the modified butyl rubber.

[0087] At 160°C, the modified butyl rubber, polyisobutylene mixture, plasticizer, tackifying resin and antioxidant were added to the kneader in sequence according to Table 5, and mixed for 45 minutes under -0.1MPa vacuum protection; then the inorganic filler, reinforcing agent, water absorbent, light stabilizer and metal salt were added in sequence, and mixed thoroughly for 120 minutes under -0.1MPa vacuum protection to obtain the self-healing butyl hot melt adhesive for photovoltaic modules.

[0088] Table 5

[0089]

[0090]

[0091] Comparative Example 1

[0092] The difference between this comparative example and Example 1 is that no metal salt was added.

[0093] 300g of brominated butyl rubber (raw rubber Mooney viscosity ML) 1+8 =33, bromine content 1.9wt%, bromine molar amount 0.071mol) was dissolved in 2L of tetrahydrofuran, and then 13.3g of HO(CH2)7CH=CHCOOH (0.071mol, commercially available) and 9.8g of potassium carbonate (0.071mol, commercially available) were added to the solution. After stirring at room temperature for 12 hours, the solid was filtered and the tetrahydrofuran was removed by rotary evaporation. The obtained product was dissolved in 300mL of toluene, and 8.7g of HSi(OCH3)3 (0.071mol, commercially available) and 4.4mg of chloroplatinic acid (mass of 0.05% of the mass of the hydrogen-containing silane) were added. The temperature was raised to 70℃ and reacted for 6 hours, and then the temperature was raised to 100℃ and the reaction was continued for 7 hours. Finally, the temperature in the reactor was raised to 110℃ and the solvent was removed by vacuum to obtain the modified butyl rubber.

[0094] At 150°C, butyl rubber, polyisobutylene mixture, plasticizer, tackifying resin and antioxidant were added to the kneader in sequence according to Table 6, and mixed for 30 minutes under -0.1MPa vacuum protection; then inorganic filler, reinforcing agent, light stabilizer and water absorbent were added in sequence, and mixed thoroughly for 120 minutes under -0.1MPa vacuum protection to obtain butyl hot melt adhesive for photovoltaic modules.

[0095] Table 6

[0096]

[0097]

[0098] Comparative Example 2

[0099] The difference between this comparative example and Example 1 is that the brominated butyl rubber was not modified.

[0100] At 150°C, add brominated butyl rubber (raw rubber Mooney viscosity ML) to the kneader in the order listed in Table 7. 1+8 =33, bromine content 1.9wt%, commercially available), polyisobutylene mixture, plasticizer, tackifying resin and antioxidant, are mixed under vacuum for 30 minutes; then inorganic filler, reinforcing agent, water absorbent, light stabilizer and metal salt are added in sequence, and mixed thoroughly under -0.1MPa vacuum for 120 minutes to obtain butyl hot melt adhesive for photovoltaic modules.

[0101] Table 7

[0102]

[0103]

[0104] Comparative Example 3

[0105] The difference between this comparative example and Example 1 is that no hydroxyl acrylate compounds were added during the preparation of the modified butyl rubber.

[0106] 300g of brominated butyl rubber (raw rubber Mooney viscosity ML) 1+8 =33, bromine content 1.9wt%, bromine molar amount 0.071mol, commercially available) was dissolved in 300mL toluene, 8.7g HSi(OCH3)3 (0.071mol, commercially available) and 4.4mg chloroplatinic acid (mass equal to 0.05% of the mass of the hydrogen-containing silane, commercially available) were added, the temperature was raised to 70℃, and the reaction was carried out for 6 hours. Then the temperature was raised to 100℃ and the reaction was continued for 7 hours. Finally, the temperature in the reaction vessel was raised to 110℃ and the solvent was removed by vacuum to obtain the modified butyl rubber.

[0107] At 150°C, the modified butyl rubber, polyisobutylene mixture, plasticizer, tackifying resin and antioxidant were added to the kneader in sequence according to Table 8, and mixed for 30 minutes under -0.1MPa vacuum protection; then the inorganic filler, reinforcing agent, water absorbent, light stabilizer and metal salt were added in sequence, and mixed thoroughly for 120 minutes under -0.1MPa vacuum protection to obtain butyl hot melt adhesive for photovoltaic modules.

[0108] Table 8

[0109]

[0110] Comparative Example 4

[0111] The difference between this comparative example and Example 1 is that no hydrogen-containing silane and platinum catalyst were added during the preparation of the modified butyl rubber.

[0112] 300g of brominated butyl rubber (raw rubber Mooney viscosity ML) 1+8 =33, bromine content 1.9wt%, bromine molar amount 0.071mol, commercially available) was dissolved in 2L of tetrahydrofuran, and then 13.3g of HO(CH2)7CH=CHCOOH (0.071mol, commercially available) and 9.8g of potassium carbonate (0.071mol, commercially available) were added to the solution. After stirring at room temperature for 12 hours, the solid was filtered and the tetrahydrofuran was removed to obtain the modified butyl rubber.

[0113] At 150°C, add modified butyl rubber, polyisobutylene mixture, plasticizer, tackifying resin and antioxidant to the kneader in sequence according to Table 9, and mix under vacuum for 30 minutes; then add inorganic filler, reinforcing agent, water absorbent, light stabilizer and metal salt in sequence, and mix thoroughly under vacuum for 120 minutes to obtain self-healing butyl hot melt adhesive for photovoltaic modules.

[0114] Table 9

[0115]

[0116] Comparative Example 5

[0117] The difference between this comparative example and Example 1 is that the hydroxyl acrylate compound was replaced with H2NCOCH=CHCOOH during the preparation of the modified butyl rubber.

[0118] 300g of brominated butyl rubber (raw rubber Mooney viscosity ML) 1+8=33, bromine content 1.9wt%, bromine molar amount 0.071mol, commercially available) was dissolved in 2L of tetrahydrofuran, and then 8.2g of H2NCOCH=CHCOOH (0.071mol, commercially available) and 9.8g of potassium carbonate (0.071mol, commercially available) were added to the solution. After stirring at room temperature for 12 hours, the solid was filtered and the tetrahydrofuran was removed by rotary evaporation. The obtained product was dissolved in 300mL of toluene, and 8.7g of HSi(OCH3)3 (0.071mol, commercially available) and 4.4mg of chloroplatinic acid (0.05% of the mass of the hydrogen-containing silane, commercially available) were added. The temperature was raised to 70℃ and reacted for 6 hours, and then the temperature was raised to 100℃ and the reaction was continued for 7 hours. Finally, the temperature in the reaction vessel was raised to 110℃ and the solvent was removed by vacuum to obtain the modified butyl rubber.

[0119] At 150°C, the modified butyl rubber, polyisobutylene mixture, plasticizer, tackifying resin and antioxidant shown in Table 10 are added sequentially to a kneader and mixed for 30 minutes under vacuum protection of -0.1MPa; then the inorganic filler, reinforcing agent, water absorbent, light stabilizer and metal salt shown in Table 10 are added sequentially and mixed thoroughly for 120 minutes under vacuum protection of -0.1MPa to obtain a self-healing butyl hot melt adhesive for photovoltaic modules.

[0120] Table 10

[0121]

[0122]

[0123] The butyl hot melt adhesives prepared in Examples 1-5 and Comparative Examples 1-5 were subjected to the performance tests shown in Table 11. The performance test methods for the samples in Table 11 are as follows:

[0124] 1. Double-glass shear strength: Shear strength shall be tested according to the relevant methods specified in GB / T 7124-2008;

[0125] 2. Self-healing test: The fracture surfaces of the samples that have completed the shear strength test are reassembled and placed at room temperature for 7 days. Then, the double-glass shear strength test is performed according to GB / T 7124-2008.

[0126] 3. 38℃, 90%RH water vapor transmission rate: The test shall be conducted in accordance with the provisions of GB / T 26253-2010. Place the putty on the release paper, heat it to a suitable temperature, and then press it into a sheet with a thickness of (1±0.1) mm, a length of not less than 120 mm, and a width of not less than 120 mm. Take a circular test piece with a diameter of not less than 100 mm for testing.

[0127] The results are shown in Table 11.

[0128] As shown in Table 11, the butyl hot melt adhesive in Comparative Example 1 did not contain any coordinating metal salts, Comparative Example 2 did not modify the butyl rubber, and the modified butyl rubber in Comparative Example 3 did not introduce hydroxyl acrylic acid compounds. The strength of the butyl hot melt adhesives prepared in Comparative Examples 1-3 was lower than that in Examples 1-5, and none of them had self-healing properties. This was manifested in a significant reduction in the shear strength of the samples after fracture splicing. Furthermore, Comparative Examples 1-3 lacked a physical cross-linking network, resulting in higher water vapor permeability than Examples 1-5. The butyl hot melt adhesives prepared in Examples 1-5 introduced both hydroxyl acrylic acid compounds and siloxanes. After fracture splicing, the samples all recovered most of their shear strength, achieving self-healing of the butyl hot melt adhesive at room temperature. The butyl hot melt adhesive prepared in Comparative Example 4 only introduced hydroxyl acrylic acid compounds without introducing siloxanes. Although it also had some self-healing ability, it did not form a good chemical bond with the substrate, and its strength was much lower than that in Examples 1-5. The lack of a chemical cross-linking network also resulted in higher water vapor permeability than Examples 1-5.

[0129] Comparative Example 5 was modified using amide-based compounds. Since these compounds do not react with halogenated butyl rubber, they cannot be grafted onto the butyl rubber polymer chain, which reduces the crosslinking density and self-healing properties of the material. The butyl hot melt adhesive prepared in Comparative Example 5 showed that the shear strength and fracture splicing shear strength of the sample were much lower than those in Examples 1-5. Furthermore, the presence of small molecules affected the compactness of the material, resulting in a much higher water vapor permeability than in Examples 1-5.

[0130] Table 11 Summary of butyl hot melt adhesive properties in examples

[0131]

[0132] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A modified butyl rubber, characterized in that, It is obtained by reacting halogenated butyl rubber with hydroxyl olefin compounds and hydrogen-containing silanes in sequence; The structural formula of the hydroxyolefin compound is HO(CH2). m CH=CHCOOH, where m is selected from: 2, 3, 4, 5, 6, 7, 8; The structural formula of the hydrogen-containing silane is HSi(R1)(OR2)2, wherein R1 is selected from: C1~C6 alkoxy, C1~C6 alkyl, and R2 is selected from: C1~C6 alkyl. The molar ratio of halogen groups, hydroxyl olefin compounds, and hydrogen-containing silanes in the halogenated butyl rubber is 1:0.8-3:0.8-3; The preparation method of the modified butyl rubber includes the following steps: (1) The halobutyl rubber and hydroxyolefin compounds are reacted in an organic solvent under the action of an inorganic base to obtain an intermediate product; (2) The intermediate product and the hydrogen-containing silane are reacted in an organic solvent under the action of a platinum catalyst to obtain the modified butyl rubber.

2. The modified butyl rubber according to claim 1, characterized in that, The halogenated butyl rubber is brominated butyl rubber and / or chlorinated butyl rubber; and / or... The raw rubber Mooney viscosity (ML) of the halogenated butyl rubber 1+8 27~50; and / or, The halogenated butyl rubber contains 1-2.2% halogen groups by mass.

3. The modified butyl rubber according to claim 2, characterized in that, The raw rubber Mooney viscosity (ML) of the halogenated butyl rubber 1+8 It is 30~40.

4. The modified butyl rubber according to claim 1, characterized in that, R1 is selected from: -OCH3, -OCH2CH3, -CH3, -CH2CH3, and R2 is -CH3 or -CH2CH3.

5. The modified butyl rubber according to any one of claims 1-4, characterized in that, The molar ratio of halogen groups, hydroxyl olefin compounds, and hydrogen-containing silanes in the halogenated butyl rubber is 1:0.9-1.1:0.9-1.

1.

6. A method for preparing the modified butyl rubber according to any one of claims 1-5, characterized in that, Includes the following steps: (1) The halobutyl rubber and hydroxyolefin compounds are reacted in an organic solvent under the action of an inorganic base to obtain an intermediate product; (2) The intermediate product and the hydrogen-containing silane are reacted in an organic solvent under the action of a platinum catalyst to obtain the modified butyl rubber.

7. The method for preparing modified butyl rubber according to claim 6, characterized in that, The organic solvent in step (1) is tetrahydrofuran; and / or, The inorganic base in step (1) is potassium carbonate; and / or, The reaction temperature in step (1) is 15℃~35℃, and the reaction time is 10 hours~20 hours; and / or, The platinum catalyst in step (2) is chloroplatinic acid or a castor catalyst; and / or, The mass ratio of the hydrogen-containing silane to the platinum catalyst is 1:0.02% to 0.08%; and / or, The organic solvent in step (2) is toluene; and / or, The reaction in step (2) includes: reacting at a temperature of 60℃~90℃ for 2 hours to 8 hours, and then raising the temperature to 70℃~100℃ to continue the reaction for 3 hours to 9 hours.

8. The method for preparing modified butyl rubber according to claim 6, characterized in that, The inorganic alkali in step (1) is potassium carbonate, and the molar ratio of the halogen group of the halogenated butyl rubber to potassium carbonate is 1:1~2.

9. A self-healing butyl hot melt adhesive for photovoltaic modules, characterized in that, The raw materials used in its preparation include the modified butyl rubber as described in any one of claims 1-5.

10. The self-healing butyl hot melt adhesive for photovoltaic modules according to claim 9, characterized in that, It is prepared from raw materials comprising the following components, in parts by weight: The modified butyl rubber is 1-40 parts. 10-80 parts of polyisobutylene 5-20 parts of tackifying resin, Plasticizer 5-30 parts, 1-10 parts absorbent 10-30 parts of inorganic filler 8-30 parts of reinforcing agent Antioxidant 0.5-3 parts, Light stabilizer 0.5-3 parts, 1-10 parts of metal salt; The metal salt is an iron salt and / or a zinc salt.

11. The self-healing butyl hot melt adhesive for photovoltaic modules according to claim 10, characterized in that, The self-healing butyl hot melt adhesive for photovoltaic modules, by weight, is prepared from raw materials comprising the following components: The modified butyl rubber is 1-5 parts. 15-40 parts of polyisobutylene 5-10 parts of tackifying resin, 5-8 parts plasticizer 2-6 parts absorbent 15-25 parts of inorganic filler 8-15 parts of reinforcing agent Antioxidant 1-3 parts, 1-3 parts light stabilizer Metal salt 1-6 parts.

12. The self-healing butyl hot melt adhesive for photovoltaic modules according to claim 10 or 11, characterized in that, The polyisobutylene is composed of medium-molecular-weight polyisobutylene and high-molecular-weight polyisobutylene, wherein the medium-molecular-weight polyisobutylene has a viscosity-average molecular weight of 60,000 to 95,000, and the high-molecular-weight polyisobutylene has a viscosity-average molecular weight of 200,000 to 500,000; and / or, The plasticizer is one or more of polybutene, phthalate, dioctyl adipate, and diisooctyl adipate; and / or, The tackifying resin is selected from one or more combinations of C5 petroleum resin, C9 petroleum resin, terpene resin, styrene-grafted terpene resin, polyterpene resin, and rosin resin; and / or, The water-absorbing agent is selected from one or more combinations of calcium oxide, molecular sieve, calcium sulfate, anhydrous calcium chloride, anhydrous magnesium sulfate, and activated alumina; and / or, The inorganic filler is selected from one or more combinations of mica powder, silica fume, kaolin, calcium carbonate, talc, kaolin, clay, and diatomaceous earth; and / or, The reinforcing agent is selected from one or a combination of two of carbon black and fumed silica; and / or, The antioxidant is selected from one or more combinations of the following: pentaerythritol tetrakis[2-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 2,6-di-tert-butyl-4-methylphenol, tris[2,4-di-tert-butylphenyl]phosphite, 2-methyl-4,6-dinonylphenol, 2,6-di-tert-butyl-α-methoxy-p-cresol, 2,4,6-tri-tert-butylphenol, and 2,2,4-trimethyl-1,2-dihydroquinoline polymer; and / or... The light stabilizer is selected from 2'-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole and / or 2-[2-hydroxy-5-tert-octylphenyl)benzotriazole.

13. The self-healing butyl hot melt adhesive for photovoltaic modules according to claim 10 or 11, characterized in that, The polyisobutylene is composed of medium molecular weight polyisobutylene and high molecular weight polyisobutylene in a mass ratio of 1:0.5-1.

5. The medium molecular weight polyisobutylene has a viscosity-average molecular weight of 60,000 to 95,000, and the high molecular weight polyisobutylene has a viscosity-average molecular weight of 200,000 to 500,000.

14. The self-healing butyl hot melt adhesive for photovoltaic modules according to claim 10 or 11, characterized in that, The metal salt is zinc chloride and / or ferric chloride.

15. A method for preparing a self-healing butyl hot melt adhesive for photovoltaic modules according to any one of claims 10-14, characterized in that, Includes the following steps: At 110℃~160℃, the modified butyl rubber, polyisobutylene, plasticizer, tackifying resin and antioxidant are added sequentially to a kneader and mixed under vacuum for 20 minutes to 130 minutes; then the inorganic filler, reinforcing agent, water absorbent, light stabilizer and metal salt are added sequentially and mixed under vacuum for 60 minutes to 180 minutes to obtain the self-healing butyl hot melt adhesive for photovoltaic modules.

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