A fast-curing acrylic adhesive and applications thereof

Abstract

The application provides a kind of fast curing acrylic glue and application, the fast curing acrylic glue is prepared from the following components according to weight parts: butyl nitrile rubber of terminal methacrylate is 13-17 parts;Polyurethane acrylate is 5-8 parts;Monofunctional acrylate monomer is 14-20 parts;Two functionality acrylate monomer is 7-13 parts;Three functionality acrylate monomer is 1-3 parts;Peroxide is 0.5-1.5 parts;Polymerization inhibitor is 0.01-0.04 parts;Coupling agent is 0.5-0.7 parts.The acrylic glue provided by the application has the advantages of fast curing, low volume resistivity after adding silver powder curing, good bonding strength, moderate elastic modulus, and can be used for photovoltaic tile conductive silver glue.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of adhesives, in particular to a kind of fast curing acrylic glue and application. BACKGROUND

[0002] Solar cell is an electrical device that converts light energy into electrical energy using photovoltaic effect. Traditional solar cells collect the current generated by the cell through busbars and fingers, and the current is finally connected to external leads through solder strips. Busbars and fingers are formed by conductive silver paste through high-temperature sintering. Due to the presence of solder strips, a shadow dead zone is formed in the light absorption area, which has a negative impact on the photoelectric conversion efficiency. The shingled photovoltaic module is connected in series in the form of overlapping cell pieces. The overlapping parts are bonded together with conductive adhesive. The conductive adhesive not only connects the cell pieces, but also conducts electricity.

[0003] The existing shingled conductive adhesive is mainly based on single-component epoxy resin, single-component silicone resin and single-component acrylic resin adhesion technology. The main advantage of epoxy adhesive is high bonding strength, but the curing time is too long, which affects the process efficiency. Single-component silicone resin has good flexibility and low internal stress after curing, but the bonding strength is low. Single-component acrylic resin has fast curing speed and high bonding strength, but it is rigid and has high modulus, which is prone to cracking under the condition of cold and hot impact with force load, resulting in poor reliability and module failure.

[0004] Chinese patent CN109439268A discloses a low Tg low silver content conductive adhesive for photovoltaic shingled module. The silver-containing conductive adhesive uses multi-functional (functional group 6-9) polybutadiene type polyurethane acrylate and multi-functional (1.5-3) VTBN (vinyl terminated butyronitrile rubber) as the base oligomer, supplemented with active acrylic monomer diluent / peroxide and other additives. The system has fast curing speed and excellent conductive performance, but the multi-functional polybutadiene type polyurethane acrylate in the raw material involves a complex two-step reaction synthesis process.

[0005] Chinese patent CN103928077A discloses a conductive adhesive, the polymer matrix resin of which is composed of at least one ethylene / alkyl (meth)acrylate copolymer elastomer and at least one ethylene-vinyl acetate (EVA) copolymer. The adhesive needs to be hot-pressed into a film and cut into strips for use, which is relatively complex compared with the screen printing coating process.

[0006] Therefore, there is a need to develop a new acrylic shingled conductive adhesive with good weather resistance, fast curing speed, balanced bonding strength and internal stress (modulus) of the cured product. SUMMARY

[0007] The first object of the present application is to provide a fast curing acrylic glue.

[0008] To achieve the above object, the present application adopts the following technical solutions:

[0009] A quick-curing acrylic adhesive is characterized in that the quick-curing acrylic adhesive is prepared from the following components in parts by weight:

[0010] The methacrylate-terminated nitrile rubber is 13-17 parts;

[0011] The polyurethane acrylate is 5-8 parts;

[0012] The monofunctional acrylate monomer is 14-20 parts;

[0013] The difunctional acrylate monomer is 7-13 parts;

[0014] The trifunctional acrylate monomer is 1-3 parts;

[0015] The peroxide is 0.5-1.5 parts;

[0016] The polymerization inhibitor is 0.01-0.04 parts;

[0017] The coupling agent is 0.5-0.7 parts.

[0018] In addition to the above technical solutions, the present application can also adopt or combine the following technical solutions:

[0019] As a preferred technical solution of the present application, the components are as follows in parts by weight:

[0020] The methacrylate-terminated nitrile rubber is a parts;

[0021] The polyurethane acrylate is b parts;

[0022] The monofunctional acrylate monomer is c parts;

[0023] The difunctional acrylate monomer is d parts;

[0024] The trifunctional acrylate monomer is e parts;

[0025] The peroxide is f parts;

[0026] The polymerization inhibitor is g parts;

[0027] The coupling agent is h parts;

[0028] Wherein, a / b = 2-3;

[0029] (a+b) / (c+d+e) = 0.7-0.8;

[0030] c / (c+d) = 0.55-0.7;

[0031] e / (c+d) = 0.05-0.1.

[0032] As a preferred technical solution of the present application: the main chain of the end methacrylate butyl nitrile rubber is formed by block polymerization of butadiene monomers and acrylonitrile monomers, and the molar proportion of the acrylonitrile monomers is 30%-45%, preferably 33%.

[0033] As a preferred technical solution of the present application: the end group of the end methacrylate butyl nitrile rubber is a methacrylate group, and the molecular weight is 3500-4500, preferably 3700-4000.

[0034] As a preferred technical solution of the present application: the functionality of the methacrylate group is 2.1-3.0, preferably 2.2-2.6.

[0035] As a preferred technical solution of the present application: the end methacrylate butyl nitrile rubber is preferably Hypro 1300X33LC and Hypro 1300X43LC.

[0036] As a preferred technical solution of the present application: the polyurethane acrylate is an aliphatic urethane di(meth)acrylate, preferably CN9002 and CN9021 of Arkema Company, SR307, EPION400V and 450A of Kaneka Company, etc.

[0037] As a preferred technical solution of the present application: the monofunctional acrylate monomer is at least one of isobornyl acrylate (IBOA), (meth)acrylic acid isobornyl ester, tetrahydrofurfuryl acrylate (THFA), methyl methacrylate (MMA), N,N-dimethyl acrylamide (DMAA), cyclo-trihydroxymethylpropane methyl acetal acrylate (CTFA), diphenyloxyethyl acrylate (PHEA), beta-hydroxyethyl acrylate, tetrahydrofurfuryl (meth)acrylate, long-chain (meth)acrylic esters, isooctyl (meth)acrylate, lauryl (meth)acrylate, and N,N-dimethyl acrylamide.

[0038] The long-chain (meth)acrylic esters include isooctyl acrylate, lauryl acrylate, isodecyl acrylate, tridecyl acrylate, octadecyl acrylate, and stearyl methacrylate.

[0039] The two-functionality acrylate monomer is at least one of 1,6-hexanediol diacrylate, tetra(ethylene glycol) diacrylate, tripropyleneglycol diacrylate, hydroxyl pivalic neopentylglycol diacrylate, tricyclodecane dimethanol diacrylate;

[0040] The three-functionality acrylate monomer is at least one of trimethylpropane triacrylate, pentaerythritol triacrylate, ditrimethylolpropane triacrylate, ethoxylated pentaerythritol tetraacrylate, neopentylglycol propoxylate diacrylate.

[0041] As a preferred technical solution of the present application: the peroxide is at least one of benzoyl peroxide (BPO), tert-butyl peroxy-2-ethylhexanoate, di-tert-butyl peroxide, tert-butyl peroxybenzoate, tert-butyl peroxyneodecanoate, tert-amyl peroxy-2-ethylhexanoate (Arkema Luperox 575), cumene hydroperoxide (CHPO), di-tert-butyl peroxide (DTBP), dicumyl peroxide (DCP), tert-amyl peroxyneodecanoate, diisopropyl peroxydicarbonate.

[0042] As a preferred technical solution of the present application: the polymerization inhibitor is at least one of hydroquinone, tert-butylcatechol (TBC), butylated hydroxytoluene, 2,6-dinitro-p-cresol (I-95), p-methoxyphenol.

[0043] As a preferred technical solution of the present application: the coupling agent is a silane coupling agent or a titanate coupling agent;

[0044] The coupling agent is preferably silane coupling agent KH-560, silane coupling agent KH-570; or, the coupling agent is preferably titanate coupling agent NDZ-401, titanate coupling agent NDZ-201.

[0045] The present application also has an object to provide the use of the above-mentioned fast-curing acrylic adhesive.

[0046] To this end, the above-mentioned objects of the present application are achieved by the following technical solutions:

[0047] According to the use of the fast-curing acrylic adhesive as a photovoltaic shingle conductive adhesive, conductive silver powder is added to the fast-curing acrylic adhesive.

[0048] The conductive silver powder is spherical, flaky or a mixture of the two; the average particle size of the conductive silver powder is 0.3-30 μm, preferably 0.5-15 μm.

[0049] Commercially available silver powders include, but are not limited to, Metalor AA3462, AA-192N, P543-14, and Ames Goldsmith's KP84, KP74.

[0050] The present application provides a kind of fast curing acrylic glue and application, using end methacrylate polybutadiene and polyurethane methacrylate oligomer composite, single, double and three officials acrylic monomer compound, in the cooperation of peroxide initiator, polymerization inhibitor, silane coupling agent and the like auxiliary and silver powder, obtain conductive silver glue, with fast curing, and the volume resistivity of curing is low, bonding strength is good, the advantages of moderate elastic modulus, can be used for photovoltaic tile conductive silver glue. DETAILED DESCRIPTION

[0051] The present application is further described in detail with reference to specific examples.

[0052] 1. Test preparation

[0053] 1.1 Test materials

[0054]

[0055] 1.2 Performance test

[0056] Bonding strength: test method refers to "HG / T 5912-2021 conductive adhesive", silicon wafer size is: 1mm x 1mm; substrate is silver-plated copper sheet, curing condition is hot table 150℃ x 1min; test equipment DAGE-4000P multifunctional push-pull machine, USA Nordson DAGE Precision Industries LTD, shear strength is push force size (unit is kgF); 5 samples of each glue, take average value.

[0057] Glass transition temperature and modulus: DMA method measures the glass transition temperature of cured material under curing condition 2, Mettler Toledo DMA861 dynamic mechanical analyzer; adopts tensile measurement mode, refers to "ASTM D5026-15", sample size is: 15mm x 4mm x 1mm, heating rate 5k / min, 25℃-200℃, load frequency = 1Hz;

[0058] Volume resistivity test: according to the following two curing conditions, film thickness is 80 μm; according to industry standard "HG / T 5912 conductive adhesive" test, and calculate volume resistivity, the result is converted to Ω·cm.

[0059] Curing condition 1: test piece is cured on 150℃ hot table for 45s;

[0060] Curing condition 2: test piece is cured in 150℃ oven for 10min.

[0061] 2. Test procedure

[0062] 2.1 Preparation of glue (Example 1 as an example):

[0063] Take polyurethane acrylate 6.9 parts, liquid butyl nitrile rubber VTBN with methyl methacrylate end group 13.7 parts, isobornyl acrylate 19.6 parts, di-functional acrylate monomer 8.4 parts, tri-functional acrylate monomer 1.4 parts, peroxide 0.75, dicumyl peroxide (DCP) 0.75 parts, polymerization inhibitor hydroquinone 0.015 parts, 0.52 parts of silane coupling agent KH-560, add to the mixing kettle, mix at 800 rpm for 15 min, then add silver powder 76.92 parts, disperse at 800 rpm for 15 min, then vacuum (vacuum degree <-0.095 MPa) degassing for 10 min, normal pressure discharge; get conductive glue.

[0064] Table 1

[0065]

[0066] Curing condition 1: hot stage 150℃ for 45s.

[0067] Curing condition 2: put into oven 150℃, heat for 10min.

[0068] Table 2

[0069]

[0070]

[0071] Curing condition 1: hot stage 150℃ for 45s.

[0072] Curing condition 2: put into oven 150℃, heat for 10min.

[0073] From Example 1 to Example 8: the volume resistivity of the cured object placed in the 150℃ oven for 1min changes little compared with that placed in the 150℃ hot stage for 45s, which can be considered that the curing degree under the two conditions is the same. That is, curing condition 1 has realized rapid curing, and has good electrical performance.

[0074] Comparative Example 1, relative to Example 1, the polyurethane acrylate oligomer was replaced by the methacrylate-terminated nitrile rubber, and the tensile modulus and glass transition temperature and adhesive strength of the cured product were greatly reduced, and the corresponding volume resistivity was greatly increased; while Comparative Example 2, relative to Example 2, the methacrylate-terminated nitrile rubber was replaced by the polyurethane acrylate oligomer, and the tensile modulus and glass transition temperature and adhesive strength of the cured product were greatly increased, and the volume resistivity was slightly decreased.

[0075] Example 4, relative to Example 5, the content of the methacrylate-terminated nitrile rubber was lower than the polyurethane acrylate oligomer (2:1 vs 3:1), and under the same conditions, the glass transition temperature of the cured product was relatively high, and the volume resistivity was also relatively low. Similar situations also exist in Example 1 and Example 2.

[0076] Comparative Example 3 and Example 7, the ratio of the mono-functional acrylate monomer to the two-functional acrylate monomer was increased, resulting in an increase in volume resistivity, and a decrease in glass transition temperature and adhesive strength and modulus, which may be related to the decrease in crosslinking density of the curing system. Similar phenomena can also be seen in the comparison of Example 1 and Example 4, and the comparison of Example 7 and Example 8.

[0077] Comparative Example 4 and Example 8, the proportion of the sum of the contents of the two oligomers to the sum of the contents of the three monomers was increased, resulting in an increase in volume resistivity, and a decrease in glass transition temperature, modulus and adhesive strength.

[0078] Example 9 and Examples 6, 10, the corresponding silver powder content was 1.0 times, 1.5 times and 2.0 times the sum of the amounts of the other components, and as the silver content increased, the volume resistivity and adhesive strength showed a downward trend.

[0079] The above specific embodiments are used to explain and illustrate the present application, and are only preferred embodiments of the present application, and are not limiting on the present application, and any modifications, equivalent replacements, improvements, etc. made to the present application fall within the protection scope of the present application.

Claims

1. A fast-curing acrylic glue, characterized by: The fast-cured acrylic adhesive is prepared from the following components by weight parts: The end-methyl acrylate butyl nitrile rubber is 13-17 parts; The polyurethane acrylate is 5-8 parts; The monofunctional acrylate monomer is 14-20 parts; The difunctional acrylate monomer is 7-13 parts; The trifunctional acrylate monomer is 1-3 parts; The peroxide is 0.5-1.5 parts; The polymerization inhibitor is 0.01-0.04 parts; The coupling agent is 0.5-0.7 parts; The main chain of the end-methyl acrylate butyl nitrile rubber is formed by block polymerization of butadiene monomers and acrylonitrile monomers, and the molar proportion of the acrylonitrile monomers is 30%-45%; The end group of the end-methyl acrylate butyl nitrile rubber is a methyl acrylate group, and the molecular weight is 3500-4500; The end-methyl acrylate functionality of the end-methyl acrylate butyl nitrile rubber is 2.1-3.0; The end-methyl acrylate butyl nitrile rubber is a parts; The polyurethane acrylate is b parts; The monofunctional acrylate monomer is c parts; The difunctional acrylate monomer is d parts; The trifunctional acrylate monomer is e parts; The peroxide is f parts; The polymerization inhibitor is g parts; The coupling agent is h parts; Wherein, (a+b) / (c+d+e)=0.7-0.

8.

2. The quick-curing acrylic glue according to claim 1, characterized in that: The molar proportion of the acrylonitrile monomers is 33%.

3. The quick-curing acrylic adhesive of claim 1, wherein: The molecular weight of the end-methyl acrylate butyl nitrile rubber is 3700-4000.

4. The quick-curing acrylic adhesive of claim 3, wherein: The end-methyl acrylate functionality of the end-methyl acrylate butyl nitrile rubber is 2.2-2.

6.

5. The quick-curing acrylic adhesive of claim 1, wherein: The polyurethane acrylate is an aliphatic urethane di(meth)acrylate.

6. The quick-curing acrylic glue of claim 1, wherein: said monofunctional acrylate monomer is isobornyl acrylate, isobornyl methacrylate, tetrahydrofurfuryl acrylate, methyl methacrylate, N,N - at least one of dimethyl acrylamide, cyclotrimethylolpropane formal acrylate, diphenyloxyethyl acrylate, tetrahydrofurfuryl (meth)acrylate, isooctyl (meth)acrylate, lauryl (meth)acrylate, N,N - at least one of dimethyl acrylamide, cyclotrimethylolpropane formal acrylate, diphenyloxyethyl acrylate, tetrahydrofurfuryl (meth)acrylate, isooctyl (meth)acrylate, lauryl (meth)acrylate, The difunctional acrylate monomer is at least one of 1,6-hexanediol diacrylate, tetra(ethylene glycol) diacrylate, tripropylene glycol diacrylate, and tricyclodecane dimethanol diacrylate; The trifunctional acrylate monomer is at least one of trimethylpropane triacrylate and pentaerythritol triacrylate.

7. The quick-curing acrylic glue of claim 1, wherein: The peroxide is at least one of benzoyl peroxide, tert-butyl peroxy-2-ethylhexanoate, di-tert-butyl peroxide, tert-butyl peroxybenzoate, tert-butyl peroxyneodecanoate, tert-amyl peroxy-2-ethylhexanoate, cumene hydroperoxide, dicumyl peroxide, tert-amyl peroxyneodecanoate, and diisopropyl peroxydicarbonate.

8. The quick-curing acrylic glue of claim 1, wherein: The polymerization inhibitor is at least one of hydroquinone, tert-butyl hydroquinone, butylated hydroxytoluene, 2,6-dinitro-p-cresol, and p-methoxyphenol.

9. The quick-curing acrylic glue of claim 1, wherein: The coupling agent is a silane coupling agent or a titanate coupling agent.

10. The quick-curing acrylic glue of claim 9, wherein: The coupling agent is silane coupling agent KH-560 or silane coupling agent KH-570.

11. The quick-curing acrylic glue of claim 9, wherein: The coupling agent is titanate coupling agent NDZ-401 or titanate coupling agent NDZ-201.

12. The fast-cured acrylic adhesive according to any one of claims 1-11 as a photovoltaic shingle conductive adhesive, wherein conductive silver powder is added to the fast-cured acrylic adhesive, the weight parts of the silver powder is 1.5 times the weight parts of other materials, and the silver powder is in a flaky shape.

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