UV (ultraviolet) isolation rubber as well as preparation method and application thereof

Abstract

The invention relates to UV (ultraviolet) isolation rubber as well as a preparation method and application thereof. The UV isolation rubber is prepared from the following raw materials in parts by weight: 5 to 20 parts of polyacrylate, 30 to 50 parts of aliphatic epoxy resin, 10 to 30 parts of acrylate monomer and 1 to 7 parts of initiator. The aliphatic epoxy resin is introduced into a polyacrylate system, and the cationic photoinitiator and the free radical photoinitiator are matched to achieve a synergistic effect, so that the prepared UV isolation glue has excellent mechanical properties, high temperature resistance and dimensional stability after being cured, and can effectively isolate and protect a battery piece; and the prepared UV isolation glue is high in transparency after being cured, and does not influence the photoelectric conversion rate of a battery piece.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of adhesives, in particular to a UV isolation adhesive and a preparation method and application thereof. BACKGROUND

[0002] BC battery (back contact battery technology) is a kind of solar cell technology which moves PN junction and metal contact to the back of the battery. This design reduces the shading of the front grid lines to the incident light, and improves the short-circuit current and conversion efficiency of the battery. During the production and transportation of BC battery, scratches will inevitably occur due to the stacking of battery pieces. In the prior art, isolation pad paper (such as sulfur-free paper) is often placed between two battery pieces to isolate the adjacent two battery pieces and protect the battery pieces. However, the conventional battery isolation pad paper needs to be continuously stacked and collected in the battery process, which is low in efficiency and high in cost, and has no gain effect on the battery assembly. Or a number of glue dot arrays are printed on the surface of the battery piece to protect the battery piece. However, air bubbles are easily generated in the printed glue dots, which reduces the light absorption rate of the battery piece and affects the power generation effect of the photovoltaic module.

[0003] CN120035229A discloses a photovoltaic cell and a photovoltaic module. A number of adhesive tapes are arranged on the light-receiving surface of the photovoltaic cell. The adhesive tapes contain polypropylene and / or polyethylene base material and epoxy acrylic resin adhesive. The adhesive tapes can form isolation protection during the stacking of the battery pieces. However, the adhesive tapes have insufficient adhesion to the battery pieces, and are prone to falling off during actual application, thereby failing to effectively protect the battery pieces.

[0004] Therefore, how to provide an isolation adhesive which can effectively form isolation protection for the battery pieces, does not affect the photoelectric conversion rate of the battery pieces, and is simple in process and convenient to use has become a problem to be solved at present. SUMMARY

[0005] To solve the above technical problems, the present application provides a UV isolation adhesive and a preparation method and application thereof. Aliphatic epoxy resin is introduced into the polyacrylate system, and cationic photoinitiator and free radical photoinitiator are matched to synergistically act, so that the prepared UV isolation adhesive has excellent mechanical properties, high temperature resistance and dimensional stability after curing. The UV isolation adhesive can effectively protect the battery pieces, and the prepared UV isolation adhesive has high transparency after curing, and does not affect the photoelectric conversion rate of the battery pieces.

[0006] In the first aspect, the present application provides a UV isolation adhesive. The preparation raw materials of the UV isolation adhesive include the following components according to weight parts:

[0007]

[0008] Among them, 5-20 parts may be, for example, 5 parts, 6 parts, 8 parts, 10 parts, 12 parts, 14 parts, 15 parts, 16 parts, 18 parts, or 20 parts, etc.; 30-50 parts may be, for example, 30 parts, 35 parts, 40 parts, 45 parts, or 50 parts, etc.; 10-30 parts may be, for example, 10 parts, 15 parts, 20 parts, 25 parts, or 30 parts, etc.; 1-7 parts may be, for example, 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, or 7 parts, etc.

[0009] The present application uses a polyacrylic resin and an aliphatic epoxy resin compound system, uses a polyacrylic resin with high adhesion and light transmission, and compounds an aliphatic epoxy resin with high hardness, high temperature resistance, and rapid surface drying compatibility, so that the cured UV isolation glue has excellent adhesion and high light transmission and high temperature resistance. The addition of acrylic ester monomer can effectively adjust the curing speed, viscosity, hardness and surface tension of the glue, so that the isolation glue has better printing performance on the battery piece and ensures the integrity of the printed pattern. The introduction of aliphatic epoxy resin uses cationic curing method, which can effectively overcome oxygen inhibition. At the same time, aliphatic epoxy resin has the characteristics of high hardness, high temperature resistance, low shrinkage and excellent adhesion. The synergistic compounding of polyacrylic resin can further improve the adhesion and high temperature and humidity resistance of the isolation glue.

[0010] Preferably, the polyacrylate includes a polyurethane acrylate.

[0011] Preferably, the number average molecular weight of the polyacrylate is 1000-5000, for example, 1000, 2000, 3000, 4000, or 5000, etc.

[0012] Preferably, the viscosity of the polyacrylate is 10000-100000, for example, 10000, 20000, 30000, 40000, 50000, 60000, 70000, 80000, 90000, or 100000, etc.

[0013] Preferably, the ratio of the mass of the aliphatic epoxy resin to the total mass of the polyacrylate and the acrylic ester monomer is 1:(0.5-1), for example, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, or 1:1, etc.

[0014] The present application further limits the ratio of the mass of the aliphatic epoxy resin to the total mass of the polyacrylate and the acrylic ester monomer to be 1:(0.5-1). If the aliphatic epoxy resin is added too much, the curing speed will be slow and the adhesion will be poor. If the aliphatic epoxy resin is added too little, the surface hardness of the glue will decrease and the battery piece cannot be effectively protected.

[0015] Preferably, the aliphatic epoxy resin comprises any one of 3,4-epoxycyclohexyl methyl 3',4'-epoxycyclohexyl carboxylate, 4-vinyl-1-cyclohexene diepoxide, bis(3,4-epoxycyclohexylmethyl) adipate, dicyclopentadiene diepoxide or tetrahydroindenyl diepoxide or a combination of at least two thereof.

[0016] Preferably, the acrylate monomer comprises any one of dipropylene glycol diacrylate, 1,6-hexanediol diacrylate, 2-phenoxyethyl acrylate or pentaerythritol triacrylate or a combination of at least two thereof.

[0017] Preferably, the initiator comprises a cationic photoinitiator and a free radical photoinitiator.

[0018] The preferred technical solution of the present application is a complex system of cationic photoinitiator and free radical photoinitiator, which can simultaneously perform free radical polymerization and cationic polymerization to form different crosslinking structures, increase the crosslinking density of the film, improve the mechanical properties and high temperature resistance, and the curing process is faster and more uniform, reducing the volume shrinkage caused by polymerization, thereby reducing internal stress and improving the dimensional stability of the UV isolation glue. The free radicals generated by the acrylate radical reaction can promote the absorption of ultraviolet light by the epoxy cationic initiator to produce Lewis acid, and the heat released during the reaction helps the rapid ring opening of the epoxy, thereby initiating polymerization. The two reactions proceed simultaneously, easily forming an interpenetrating network, thereby compensating for the shortcomings of acrylate curing oxygen inhibition, slow cationic curing speed and poor adhesion.

[0019] Preferably, the preparation raw materials of the UV isolation glue comprise 1-4 parts of cationic photoinitiator by weight, for example, it can be 1 part, 2 parts, 3 parts or 4 parts, etc.

[0020] Preferably, the preparation raw materials of the UV isolation glue comprise 1-3 parts of free radical photoinitiator by weight, for example, it can be 1 part, 1.5 parts, 2 parts, 2.5 parts or 3 parts, etc.

[0021] Preferably, the cationic photoinitiator comprises any one of diazonium salt, diaryliodonium salt, triarylsulfonium salt, alkylsulfonium salt, iron arene salt, sulfonyloxy ketone or triarylsilyl ether or a combination of at least two thereof.

[0022] Preferably, the free radical photoinitiator comprises any one of 1-hydroxycyclohexyl phenyl ketone, 2,4,6-trimethylbenzoyl-di(p-tolyl) phosphine oxide, benzophenone, isopropyl thioxanthone, phenyl bis(2,4,6-trimethylbenzoyl) phosphine oxide or 2-hydroxy-2-methyl-1-phenylpropanone or a combination of at least two thereof.

[0023] Preferably, the preparation raw materials of the UV isolation glue further comprise a leveling agent and / or a defoaming agent.

[0024] Preferably, the preparation raw materials of the UV isolation glue include 0.1-1 parts of leveling agent by weight, for example, it can be 0.1 parts, 0.2 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.8 parts or 1 part, etc.

[0025] Preferably, the preparation raw materials of the UV isolation glue include 0.1-1 parts of defoaming agent by weight, for example, it can be 0.1 parts, 0.2 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.8 parts or 1 part, etc.

[0026] Preferably, the leveling agent includes silicone leveling agent.

[0027] Preferably, the defoaming agent includes polysiloxane defoaming agent.

[0028] In a second aspect, the present application provides a preparation method of the UV isolation glue of the first aspect, and the preparation method of the UV isolation glue includes the following steps:

[0029] Mixing the preparation raw materials of the UV isolation glue according to the proportion by weight, and reacting to obtain the UV isolation glue.

[0030] Preferably, the reaction temperature of the reaction is 20-50℃, for example, it can be 20℃, 25℃, 30℃, 35℃, 40℃, 45℃ or 50℃, etc., and the reaction time is 1-2h, for example, it can be 1h, 1.2h, 1.4h, 1.6h, 1.8h or 2h, etc.

[0031] In a third aspect, the present application provides the application of the UV isolation glue of the first aspect in the BC battery.

[0032] The UV isolation glue provided by the present application forms a glue point array on the screen plate by silk-screening glue points on the surface of the BC battery, the battery piece passes through the screen plate quickly through the transmission belt, and the device forms a glue point array on the battery piece by the silk-screen printing method and then solidifies. When the battery is stacked, the glue points will be isolated from the battery piece, so as to avoid scratching the battery piece.

[0033] Preferably, the light intensity of the UV curing is 2000-4000mJ / cm 2 , for example, it can be 2000mJ / cm 2 , 2500mJ / cm 2 , 3000mJ / cm 2 , 3500mJ / cm 2 or 4000mJ / cm 2 , etc., and the time is 2-4s, for example, it can be 2s, 2.5s, 3s, 3.5s or 4s, etc.

[0034] Compared with the prior art, the present application has at least the following beneficial effects:

[0035] (1) The present application provides a UV isolation glue and its preparation method and application. By introducing aliphatic epoxy resin into the polyacrylate system, the prepared UV isolation glue has excellent mechanical properties and high temperature resistance after curing, can effectively isolate and protect the battery piece, and the prepared UV isolation glue has high transparency after curing, and will not affect the photoelectric conversion rate of the battery piece.

[0036] (2) The present application uses a complex system of cationic photoinitiator and free radical photoinitiator to improve the mechanical properties, high temperature resistance and dimensional stability of the prepared UV isolation glue after curing.

[0037] (3) The UV isolation glue provided by the present application has fast curing, and the cured UV isolation glue does not need to be repeatedly stacked and collected when used for isolating and protecting the battery piece, greatly improving the production and transportation efficiency, saving time and reducing cost.

[0038] (4) Specifically, the UV isolation glue prepared by the present application has excellent adhesion, which can reach 4-5B by hundred grid test, can reach 4H by pencil hardness test, can resist high temperature and high humidity without cracking or only slight cracking, and the light transmittance is greater than or equal to 90%. DETAILED DESCRIPTION

[0039] In order to facilitate the understanding of the present application, the present application lists the following embodiments. Those skilled in the art should understand that the embodiments are only to help understand the present application, and should not be regarded as a specific limitation on the present application.

[0040] In the following specific embodiments of the present application, the specific information of the materials used is as follows:

[0041] 1. Polyacrylate, 65350 of Longxing Material Industry Co., Ltd., number average molecular weight 1000-5000, viscosity 30000-50000;

[0042] 2. Polyacrylate, 6536-1 of Longxing Material Industry Co., Ltd., number average molecular weight 1000-5000, viscosity 15000-35000;

[0043] 3. Polyacrylate, DR-A815 of Longxing Material Industry Co., Ltd., number average molecular weight 1000-5000, viscosity 50000-80000;

[0044] 4. Aliphatic epoxy resin, TTA21P of Jiangsu Taitele New Material Technology Co., Ltd.;

[0045] 5. Aliphatic epoxy resin, TTA26 of Jiangsu Taitele New Material Technology Co., Ltd.;

[0046] 6. Aliphatic epoxy resin, TTA28 from Jiangsu Taitai New Material Science and Technology Co., Ltd.;

[0047] 7. Acrylate monomer, dipropylene glycol diacrylate;

[0048] 8. Acrylate monomer, 2-phenoxyethyl acrylate;

[0049] 9. Acrylate monomer, pentaerythritol triacrylate;

[0050] 10. Free radical photoinitiator, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (TPO);

[0051] 11. Cationic photoinitiator, triarylsulfonium salt;

[0052] 12. Leveling agent, BYK333 from BYK-Gardner Germany;

[0053] 13. Defoaming agent, Decon 6800.

[0054] Examples 1-5

[0055] Examples 1-5 respectively provide a UV isolation adhesive and a preparation method thereof, and the preparation raw material components of the UV isolation adhesive are shown in Table 1 (the amount of the raw material components of the UV isolation adhesive in Table 1 is all in parts by weight), wherein “--” represents that the component is not added, and the preparation method is as follows:

[0056] The preparation raw materials of the UV isolation adhesive are mixed according to the weight ratio, and the reaction is carried out, the reaction temperature is 30°C, and the time is 1.5h, to obtain the UV isolation adhesive.

[0057] Table 1

[0058]

[0059] Comparative Example 1

[0060] The present comparative example provides a UV isolation adhesive and a preparation method thereof, which is different from Example 1 in that the preparation raw material components of the UV isolation adhesive do not contain an aliphatic epoxy resin.

[0061] Comparative Example 2

[0062] The present comparative example provides a UV isolation adhesive and a preparation method thereof, which is different from Example 1 in that the addition amount of the aliphatic epoxy resin in the preparation raw material components of the UV isolation adhesive is 55 parts.

[0063] Comparative Example 3

[0064] The comparative example provides a UV isolation adhesive and a preparation method thereof, and the difference from example 1 is that the addition amount of the aliphatic epoxy resin in the raw material component of the UV isolation adhesive is 25 parts.

[0065] Test method

[0066] The UV isolation adhesives provided by examples 1-5 and comparative examples 1-3 are screen printed on the surface of the battery piece in a 20x20mm square pattern, and a 395nm area light source is used for 3000mJ / cm 2 The adhesion, hardness and high temperature and humidity resistance are tested after curing for 3s.

[0067] Light transmittance test: the UV isolation adhesives provided by examples 1-5 and comparative examples 1-3 are made into 100μm adhesive films, which are tested by a spectrophotometer.

[0068] (1) Adhesion: the crosshatch test is performed according to GB / T 9286-2021;

[0069] (2) Hardness: the pencil hardness test is performed according to ASTM D3363;

[0070] (3) High temperature and humidity resistance: the UV isolation adhesives provided by examples 1-5 and comparative examples 1-3 are applied to the battery piece and placed in an aging oven for double 85 test (85℃ and 85% humidity), and after 168h, the cracking between the adhesive dots and the battery piece is observed.

[0071] (4) Light transmittance: the light transmittance of 100μm thick adhesive film is tested by TU-1901 double beam ultraviolet visible spectrophotometer integrating sphere.

[0072] Test results

[0073] The UV isolation adhesives provided by examples 1-5 and comparative examples 1-3 are tested for performance, and the test results are shown in table 2 below:

[0074] Table 2

[0075]

[0076] From the test results, it can be seen that:

[0077] (1) From examples 1 to 3, it can be seen that the UV isolation adhesive prepared by the present application has excellent adhesion, which can reach 5B by crosshatch test, 4H by pencil hardness test, can resist high temperature and humidity without cracking, and the light transmittance is greater than or equal to 92%, which can effectively isolate and protect the battery piece, and will not affect the photoelectric conversion rate of the battery piece.

[0078] (2) As can be seen from Example 1 and Examples 4-5, the present application can achieve better adhesion and high temperature and high humidity resistance by further limiting the ratio of the mass of the aliphatic epoxy resin to the total mass of the polyacrylate and acrylate monomers.

[0079] (3) As can be seen from Preparation Example 1 and Comparative Examples 1-3, the present application improves the hardness of the UV release agent by introducing the aliphatic epoxy resin, but if the aliphatic epoxy resin is added too much, the curing speed of the glue is slow, resulting in poor adhesion, and if the aliphatic epoxy resin is added too little, the surface hardness of the glue is reduced, which cannot effectively protect the battery sheet.

[0080] The applicant declares that the above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and those skilled in the art should understand that any changes or replacements within the technical scope disclosed by the present application, which can be easily thought of by any person skilled in the art, falls within the protection scope and disclosure scope of the present application.

Claims

1. A UV isolation glue, characterized in that, The raw materials for preparing the UV isolation glue include the following components by weight: 2.The UV isolation glue according to claim 1, characterized in that, The polyacrylate includes polyurethane acrylate; Preferably, the number average molecular weight of the polyacrylate is 1000-5000; Preferably, the viscosity of the polyacrylate is 10000-100000. 3.The UV isolation adhesive according to any one of claims 1 or 2, characterized in that, The ratio of the mass of the aliphatic epoxy resin to the total mass of the polyacrylate and the acrylate monomer is 1:(0.5-1).

4. UV screening according to any one of claims 1-3, characterized in that, The aliphatic epoxy resin includes any one or a combination of at least two of 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexylmethyl carboxylate, 4-vinyl-1-cyclohexene diepoxy, bis(3,4-epoxycyclohexylmethyl) adipate, dicyclopentadiene diepoxy or tetrahydroindenyl diepoxy. 5.The UV isolating adhesive according to any one of claims 1-4, characterized in that, The acrylate monomer includes any one or a combination of at least two of dipropylene glycol diacrylate, 1,6-hexanediol diacrylate, 2-phenoxyethyl acrylate or pentaerythritol triacrylate. 6.The UV isolation adhesive according to any one of claims 1-5, characterized in that, The initiator includes a cationic photoinitiator and a free radical photoinitiator; Preferably, the raw materials for preparing the UV isolation glue include 1-4 parts of the cationic photoinitiator by weight; Preferably, the raw materials for preparing the UV isolation glue include 1-3 parts of the free radical photoinitiator by weight; Preferably, the cationic photoinitiator includes any one or a combination of at least two of diazonium salt, diaryliodonium salt, triarylsulfonium salt, alkylsulfonium salt, iron arene salt, sulfonyloxy ketone or triarylsilyl ether. Preferably, the free radical photoinitiator includes any one or a combination of at least two of 1-hydroxycyclohexyl phenyl ketone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, benzophenone, isopropyl thioxanthone, phenyl bis(2,4,6-trimethylbenzoyl) phosphine oxide or 2-hydroxy-2-methyl-1-phenylpropanone. 7.The UV isolation adhesive according to any one of claims 1-6, characterized in that, The raw materials for preparing the UV isolation glue further include a leveling agent and / or a defoaming agent; Preferably, the raw materials for preparing the UV isolation glue include 0.1-1 parts of the leveling agent by weight; Preferably, the raw materials for preparing the UV isolation glue include 0.1-1 parts of the defoaming agent by weight; Preferably, the leveling agent includes a silicone leveling agent; Preferably, the defoaming agent includes a polysiloxane defoaming agent.

8. A method of preparing the UV cut-off adhesive according to any one of claims 1 to 7, characterized in that, The preparation method of the UV isolation glue includes the following steps: The raw materials for preparing the UV isolation glue are mixed according to the weight ratio, and the reaction is carried out to obtain the UV isolation glue. 9.The method of claim 8, wherein the UV cut filter is prepared by the steps of, The reaction temperature of the reaction is 20-50℃, and the reaction time is 1-2h.

10. The UV isolation glue according to any one of claims 1-7 in the application of BC battery isolation.

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