High-cohesiveness high-temperature-resistant UV adhesive and preparation method thereof

Abstract

The invention relates to the technical field of adhesives, and particularly discloses a high-cohesiveness high-temperature-resistant UV adhesive and a preparation method thereof. The adhesive high-temperature-resistant UV adhesive is prepared from acrylic acid, phenyl methacrylate, methacrylic acid-2-hydroxyethyl ester, polyethylene glycol diacrylate, 2-hydroxyethyl methacrylate phosphate, isobornyl acrylate, epoxidized soybean oil acrylate modified silicon dioxide and alkenylated phenolic resin modified polyurethane under the action of a photoinitiator, and the adhesive high-temperature-resistant UV adhesive is prepared from acrylic acid, phenyl methacrylate, methacrylic acid-2-hydroxyethyl ester, polyethylene glycol diacrylate, 2-hydroxyethyl methacrylate phosphate, isobornyl acrylate, epoxidized soybean oil acrylate modified silicon dioxide and alkenylated phenolic resin modified polyurethane. A plurality of monomers are adopted as raw materials, a compact net structure is formed through a reasonable proportion and a cross-linking reaction, and the prepared UV adhesive forms a high-temperature-resistant skeleton structure, has the characteristics of high temperature resistance and high cohesiveness, is not easy to fall off in the use process, and is excellent in size stability and good in toughness.

Description

Technical Field

[0001] The present invention relates to the technical field of adhesives, in particular to a high-adhesive, high-temperature-resistant UV adhesive and a preparation method thereof. Background Art

[0002] UV adhesive, also known as photosensitive adhesive, is a polymer material that rapidly cures by absorbing ultraviolet light to initiate a polymerization reaction. It boasts the advantages of fast curing, no solvent volatilization, energy conservation, and environmental protection. It can bond a variety of materials and is widely used in electronic packaging, printing, optical instruments, medical devices, and other fields. Traditional UV adhesives are primarily based on acrylate monomers, which are polymerized by various acrylate monomers using photoinitiators under ultraviolet light. However, traditional acrylate UV light-curing adhesives have a low glass transition temperature and lack performance stability in high-temperature environments, causing softening, resulting in bond failure, cracking, and debonding.

[0003] Chinese patent application CN108384507A discloses a UV light-curing adhesive with high bonding strength and a preparation method thereof. The components and mass percentages of the UV light-curing adhesive are: 30-60% polyurethane acrylate, 10-30% (meth)acrylate monomer, 1-6% photoinitiator, 0.5-3% silane coupling agent, 1-10% adhesion promoter, and 10-40% filler. By adding solvent-free polyurethane acrylate, silane coupling agent, and adhesion promoter to the raw materials, the bonding strength of the UV light-curing adhesive is greatly improved. However, the UV light-curing adhesive contains a high amount of filler, has poor dispersion performance, and is prone to agglomeration, resulting in uneven curing and affecting bonding performance. In addition, the UV light-curing adhesive has average high-temperature resistance and poor bonding strength under high-temperature conditions. Chinese patent application CN105315954A discloses a novel UV light-curing adhesive, which comprises the following components, in parts by weight: 20-40 parts of polyurethane acrylate, 20-50 parts of poly(ethylhexyl acrylate), 10-30 parts of dimethylaminoethyl methacrylate, 15-30 parts of diethylene glycol dimethacrylate, 20-60 parts of acrylate monomer, 20-30 parts of hydroxyethyl methacrylate, 1-2 parts of nano-titanium oxide, 5-10 parts of wintergreen oil, 2-5 parts of photoinitiator, 2-3 parts of adhesion promoter, and 1-4 parts of auxiliary agent. The adhesive has high bonding ability, but when used for low surface energy materials, it is prone to problems such as insufficient bonding and debonding, and the nanomaterials are prone to agglomeration, which can lead to stress concentration in the adhesive layer after curing.

[0004] Therefore, the development of a UV adhesive with excellent comprehensive performance of high adhesion and high temperature resistance has a wide application market. Summary of the Invention

[0005] 1. Technical issues to be resolved

[0006] In view of the deficiencies of the prior art, the present invention provides a high-adhesion and high-temperature-resistant UV glue and a preparation method thereof, which solve the problems of general adhesion and poor high-temperature resistance of UV glue.

[0007] (II) Technical Solution

[0008] In order to achieve the above object, the present invention discloses a preparation method of a high-adhesion and high-temperature-resistant UV glue, which comprises the following steps:

[0009] Step 1: Ultrasonically disperse nano-silica into xylene. After uniform dispersion, add maleic anhydride, stir and mix, and react. After the reaction is completed, perform suction filtration, wash with absolute ethanol and deionized water, and vacuum dry at 60 °C for 24 h to obtain modified nano-silica;

[0010] Step 2: Mix epoxy soybean oil and inhibitor evenly, heat in an oil bath, then add modified nano-silica and catalyst, stir and mix, and react. After the reaction is completed, cool, perform rotary evaporation, and vacuum dry at 60 °C for 6 h to obtain epoxy soybean oil acrylate-modified silica;

[0011] Step 3: Mix phenolic resin and dimethylacetamide evenly, then add methacryloyloxyethyl isocyanate, isocyanate-terminated polyurethane, and catalyst dibutyltin dilaurate, stir and mix, and react. After the reaction is completed, perform suction filtration, wash with acetone, and vacuum dry at 60 °C for 12 h to obtain vinylated phenolic resin-modified polyurethane;

[0012] Step 4: Stir and mix acrylic acid, phenyl methacrylate, 2-hydroxyethyl methacrylate, polyethylene glycol diacrylate, 2-hydroxyethyl methacrylate phosphate, isobornyl acrylate, epoxy soybean oil acrylate-modified silica, vinylated phenolic resin-modified polyurethane, and photoinitiator. After mixing evenly, perform vacuum degassing to obtain a high-adhesion and high-temperature-resistant UV glue.

[0013] Preferably, the mass ratio of nano-silica, xylene, and maleic anhydride in Step 1 is 100:4800 - 5200:120 - 150.

[0014] Preferably, the reaction temperature in Step 1 is 110 - 120 °C, and the reaction time is 24 - 30 h.

[0015] Preferably, the mass ratio of epoxy soybean oil, inhibitor, modified nano-silica, and catalyst in Step 2 is 100:0.1 - 0.5:30 - 48:0.15 - 0.6.

[0016] Preferably, the reaction temperature in Step 2 is 115 - 120 °C, and the reaction time is 4 - 6 h.

[0017] Preferably, the catalyst in the second step is diisobutyltin dilaurate.

[0018] Preferably, the inhibitor in the second step is 4-tert-butylcatechol.

[0019] Preferably, the mass ratio of phenolic resin, dimethylacetamide, 2-(methacryloyloxy)ethyl isocyanate, isocyanate-terminated polyurethane, and diisobutyltin dilaurate in the third step is 100:900 - 1200:22 - 35:40 - 50:0.5 - 1.5.

[0020] Preferably, the reaction temperature in the third step is 60 - 65 °C, and the reaction time is 3 - 5 h.

[0021] Preferably, the specific process for preparing the high-adhesion and high-temperature-resistant UV glue in the fourth step is as follows: Add acrylic acid, phenyl methacrylate, 2-hydroxyethyl methacrylate, polyethylene glycol diacrylate, 2-hydroxyethyl methacrylate phosphate, and isobornyl acrylate into a reactor, stir and mix for 30 - 40 min at a stirring speed of 200 - 300 r / min, then add epoxy soybean oil acrylate-modified silica and stir for 30 - 60 min at a stirring rate of 400 - 500 r / min, then add vinylated phenolic resin-modified polyurethane and stir for 20 - 30 min. After mixing evenly, add a photoinitiator and stir at a stirring rate of 100 - 150 r / min for 15 - 30 min, perform vacuum degassing with a vacuum degree of -0.08 MPa to -0.1 MPa for 15 min. After the degassing is completed, transfer it to a light-proof and sealed container to obtain the high-adhesion and high-temperature-resistant UV glue.

[0022] Preferably, the mass ratio of acrylic acid, phenyl methacrylate, 2-hydroxyethyl methacrylate, polyethylene glycol diacrylate, 2-hydroxyethyl methacrylate phosphate, isobornyl acrylate, epoxy soybean oil acrylate-modified silica, vinylated phenolic resin-modified polyurethane, and photoinitiator in the fourth step is 35 - 42:40 - 50:20 - 28:10 - 16:6 - 10:4 - 7:7 - 15:100:1 - 3.

[0023] Preferably, the photoinitiator in the fourth step is composed of 1-hydroxycyclohexyl phenyl ketone and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide with a mass ratio of 3:2.

[0024] A high-adhesion and high-temperature-resistant UV glue prepared by using the preparation method of the high-adhesion and high-temperature-resistant UV glue described above.

[0025] (III) Beneficial technical effects

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0027] (1) In the present invention, maleic anhydride is used to modify nano-silica. The maleic anhydride reacts with the hydroxyl groups on the surface of nano-silica, and the acid anhydride ring opens to obtain modified nano-silica, introducing carboxyl and vinyl groups on the surface of silica. The carboxyl groups on the surface of the modified nano-silica react with the epoxy groups on epoxy soybean oil acrylate to obtain epoxy soybean oil acrylate modified silica. The hydroxyl groups on phenolic resin react with the isocyanate groups on methacryloyloxyethyl isocyanate and isocyanate-terminated polyurethane under the action of a catalyst to obtain vinylated phenolic resin modified polyurethane. Acrylic acid, phenyl methacrylate, 2-hydroxyethyl methacrylate, polyethylene glycol diacrylate, 2-hydroxyethyl methacrylate phosphate, isobornyl acrylate, epoxy soybean oil acrylate modified silica, vinylated phenolic resin modified polyurethane, and photoinitiator are stirred and mixed. After mixing evenly, vacuum degassing is carried out to obtain a high-adhesion high-temperature-resistant UV adhesive.

[0028] (2) In the present invention, nano-silica has excellent heat resistance and rigidity. Epoxy soybean oil acrylate can provide good substrate wettability and initial adhesion, reduce internal stress, and lower the brittleness of the matrix. After modifying nano-silica, the dispersibility of nano-silica is improved, effectively avoiding agglomeration. The compatibility between raw materials is good. The uniformly dispersed nano-silica in the UV adhesive matrix can form a high-temperature-resistant inorganic-organic hybrid network, improving the glass transition temperature and thermal decomposition temperature of the adhesive layer, having excellent heat resistance, and at the same time avoiding the defect of large internal stress and having excellent bonding performance. The rigid benzene ring structure of phenolic resin can effectively inhibit the thermal movement of molecular chains and has excellent high-temperature resistance. The flexible chain segments of polyurethane can improve the flexibility and mobility of the matrix. When subjected to external forces, the energy can be effectively absorbed and dispersed, enabling the adhesive layer to better adapt to external impacts and deformations and avoiding brittle fracture due to external forces. After the reaction between phenolic resin and polyurethane, the two act synergistically to form a dense network structure through cross-linking reaction, enhancing the cohesive force and avoiding the adhesive failure caused by excessive flexibility of the adhesive layer. Vinylated phenolic resin modified polyurethane can participate in photocuring, further improving the heat resistance and stability of the matrix, and at the same time having excellent mechanical properties.

[0029] (3) In the present invention, a variety of monomers are used as raw materials. Among them, the carboxyl group in the acrylic monomer has a certain polarity, which can enhance the adhesion to polar substrates. The rigid benzene ring structure in phenyl methacrylate can improve the hardness and high-temperature resistance of the matrix, and at the same time improve the chemical resistance of the matrix. The hydroxyl group in 2-hydroxyethyl methacrylate can form hydrogen bonds or chemical bonds with the hydroxyl groups on the surfaces of polar substrates such as metals and glasses, significantly enhancing the interfacial adhesion, being not easily debonded, and at the same time being able to participate in further reactions to increase the crosslinking density. Polyethylene glycol diacrylate can increase the crosslinking density of the system, improve the strength and hardness of the matrix, and improve the flexibility. The phosphate group in 2-hydroxyethyl methacrylate phosphate has strong polarity and chemical activity, and can form chemical bonds with the metal surface, which is beneficial to improving the adhesion of the adhesive to polar substrates such as metals. Isobornyl acrylate can reduce the viscosity of the system, improve the fluidity and workability of the matrix, and improve the weather resistance and surface hardness. Among them, the composite photoinitiator can rapidly generate active free radicals, achieve rapid curing at low temperature, effectively improve the production efficiency, and has a high curing rate. Through a reasonable raw material ratio, the prepared UV adhesive has a three-dimensional crosslinked network structure, forming a high-temperature resistant skeleton structure, and has the characteristics of high temperature resistance and high adhesion. The UV adhesive is not easily detached during use, and at the same time has excellent dimensional stability and good toughness. Detailed implementation mode

[0030] To facilitate the understanding of the present invention, the present invention will be described more comprehensively below. The preferred embodiments of the present invention are given below. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure content of the present invention more thorough and comprehensive.

[0031] Example 1

[0032] A preparation method of a high-adhesion and high-temperature resistant UV adhesive includes the following steps:

[0033] (1) Ultrasonically disperse nano-silica into xylene. After uniform dispersion, add maleic anhydride. The mass ratio of nano-silica, xylene, and maleic anhydride is 100:4800:120. Stir and mix to react. The reaction temperature is 110 °C, and the reaction time is 30 h. After the reaction ends, perform suction filtration, wash with absolute ethanol and deionized water, and vacuum dry at 60 °C for 24 h to obtain modified nano-silica;

[0034] (2) Mix epoxy soybean oil and the inhibitor 4-tert-butylcatechol evenly, heat them in an oil bath, and then add modified nano-silica and the catalyst diisobutyltin dilaurate. The mass ratio of epoxy soybean oil, 4-tert-butylcatechol, modified nano-silica, and diisobutyltin dilaurate is 100:0.1:30:0.15. Stir and mix them, and react at 115 °C for 6 h. After the reaction, cool, rotary evaporate, and vacuum dry at 60 °C for 6 h to obtain epoxy soybean oil acrylate modified silica;

[0035] (3) Mix phenolic resin and dimethylacetamide evenly, and then add methacryloxyethyl isocyanate, isocyanate-terminated polyurethane, and diisobutyltin dilaurate. The mass ratio of phenolic resin, dimethylacetamide, methacryloxyethyl isocyanate, isocyanate-terminated polyurethane, and diisobutyltin dilaurate is 100:900:22:40:0.5. Stir and mix them, and react at 60 °C for 5 h. After the reaction, filter by suction, wash with acetone, and vacuum dry at 60 °C for 12 h to obtain vinylated phenolic resin modified polyurethane;

[0036] (4) Add acrylic acid, phenyl methacrylate, 2-hydroxyethyl methacrylate, polyethylene glycol diacrylate, 2-hydroxyethyl methacrylate phosphate, and isobornyl acrylate into a reactor, stir and mix for 30 min at a stirring speed of 300 r / min, then add epoxy soybean oil acrylate modified silica and stir for 30 min at a stirring rate of 500 r / min, then add vinylated phenolic resin modified polyurethane and stir for 20 min. After mixing evenly, add a photoinitiator and stir at a stirring rate of 150 r / min for 15 min. The mass ratio of acrylic acid, phenyl methacrylate, 2-hydroxyethyl methacrylate, polyethylene glycol diacrylate, 2-hydroxyethyl methacrylate phosphate, isobornyl acrylate, epoxy soybean oil acrylate modified silica, vinylated phenolic resin modified polyurethane, and photoinitiator is 35:40:20:10:6:4:7:100:1. The photoinitiator is composed of 1-hydroxycyclohexyl phenyl ketone and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide with a mass ratio of 3:2. Conduct vacuum degassing at a vacuum degree of -0.08 MPa for 15 min. After degassing is completed, transfer it to a light-proof and sealed container to obtain a high-adhesion and high-temperature-resistant UV glue.

[0037] Example 2

[0038] A preparation method of a high-adhesion and high-temperature-resistant UV glue, comprising the following steps:

[0039] (1) Ultrasonically disperse nano-silica into xylene. After uniform dispersion, add maleic anhydride. The mass ratio of nano-silica, xylene, and maleic anhydride is 100:5000:130. Stir and mix to carry out the reaction. The reaction temperature is 115 °C and the reaction time is 28 h. After the reaction, perform suction filtration, wash with absolute ethanol and deionized water, and vacuum dry at 60 °C for 24 h to obtain modified nano-silica;

[0040] (2) Mix epoxy soybean oil and the inhibitor 4-tert-butylcatechol evenly, heat in an oil bath, and then add modified nano-silica and the catalyst dibutyltin dilaurate. The mass ratio of epoxy soybean oil, 4-tert-butylcatechol, modified nano-silica, and dibutyltin dilaurate is 100:0.3:36:0.3. Stir and mix, and carry out the reaction at 118 °C. The reaction time is 5 h. After the reaction, cool, perform rotary evaporation, and vacuum dry at 60 °C for 6 h to obtain epoxy soybean oil acrylate modified silica;

[0041] (3) Mix phenolic resin and dimethylacetamide evenly, and then add methacryloxyethyl isocyanate, isocyanate-terminated polyurethane, and dibutyltin dilaurate. The mass ratio of phenolic resin, dimethylacetamide, methacryloxyethyl isocyanate, isocyanate-terminated polyurethane, and dibutyltin dilaurate is 100:1000:28:42:1. Stir and mix, and carry out the reaction at 62 °C. The reaction time is 4 h. After the reaction, perform suction filtration, wash with acetone, and vacuum dry at 60 °C for 12 h to obtain vinylated phenolic resin modified polyurethane;

[0042] (4) Add acrylic acid, phenyl methacrylate, 2-hydroxyethyl methacrylate, polyethylene glycol diacrylate, 2-hydroxyethyl methacrylate phosphate, isobornyl acrylate into a reactor, stir and mix for 35 min at a stirring speed of 250 r / min. Then add epoxy soybean oil acrylate modified silica and stir for 40 min at a stirring rate of 450 r / min. Next, add vinylated phenolic resin modified polyurethane and stir for 25 min. After mixing evenly, add a photoinitiator and stir for 20 min at a stirring rate of 120 r / min. The mass ratio of acrylic acid, phenyl methacrylate, 2-hydroxyethyl methacrylate, polyethylene glycol diacrylate, 2-hydroxyethyl methacrylate phosphate, isobornyl acrylate, epoxy soybean oil acrylate modified silica, vinylated phenolic resin modified polyurethane, and photoinitiator is 38:46:25:13:7:5:10:100:2. The photoinitiator is composed of 1-hydroxycyclohexyl phenyl ketone and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide with a mass ratio of 3:2. Conduct vacuum degassing at a vacuum degree of -0.09 MPa for 15 min. After degassing is completed, transfer it to a light-proof and sealed container to obtain a high-adhesion and high-temperature-resistant UV glue.

[0043] Example 3

[0044] A preparation method of a high-adhesion and high-temperature-resistant UV glue, comprising the following steps:

[0045] (1) Ultrasonically disperse nano-silica in xylene. After dispersing evenly, add maleic anhydride. The mass ratio of nano-silica, xylene, and maleic anhydride is 100:5000:140. Stir and mix to carry out a reaction at a reaction temperature of 115 °C for 28 h. After the reaction is completed, perform suction filtration, wash with absolute ethanol and deionized water, and vacuum dry at 60 °C for 24 h to obtain modified nano-silica;

[0046] (2) Mix epoxy soybean oil and the inhibitor 4-tert-butylcatechol evenly, heat in an oil bath, and then add modified nano-silica and the catalyst dibutyltin dilaurate. The mass ratio of epoxy soybean oil, 4-tert-butylcatechol, modified nano-silica, and dibutyltin dilaurate is 100:0.4:40:0.5. Stir and mix and react at 118 °C for 5 h. After the reaction is completed, cool, perform rotary evaporation, and vacuum dry at 60 °C for 6 h to obtain epoxy soybean oil acrylate modified silica;

[0047] (3) Mix the phenolic resin and dimethylacetamide evenly, and then add methacryloyloxyethyl isocyanate, isocyanate-capped polyurethane, and diisobutyltin dilaurate. The mass ratio of phenolic resin, dimethylacetamide, methacryloyloxyethyl isocyanate, isocyanate-capped polyurethane, and diisobutyltin dilaurate is 100:1000:32:48:1.2. Stir and mix, react at 62 °C for 4 h. After the reaction is completed, perform suction filtration, wash with acetone, and dry in vacuum at 60 °C for 12 h to obtain vinylated phenolic resin-modified polyurethane;

[0048] (4) Add acrylic acid, phenyl methacrylate, 2-hydroxyethyl methacrylate, polyethylene glycol diacrylate, 2-hydroxyethyl methacrylate phosphate, and isobornyl acrylate to the reactor, stir and mix for 38 min at a stirring speed of 250 r / min. Then add epoxy soybean oil acrylate-modified silica and stir for 50 min at a stirring rate of 450 r / min. Then add vinylated phenolic resin-modified polyurethane and stir for 28 min. After mixing evenly, add a photoinitiator and stir for 25 min at a stirring rate of 120 r / min. The mass ratio of acrylic acid, phenyl methacrylate, 2-hydroxyethyl methacrylate, polyethylene glycol diacrylate, 2-hydroxyethyl methacrylate phosphate, isobornyl acrylate, epoxy soybean oil acrylate-modified silica, vinylated phenolic resin-modified polyurethane, and photoinitiator is 38:46:25:15:8:6:14:100:2.5. The photoinitiator is composed of 1-hydroxycyclohexyl phenyl ketone and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide with a mass ratio of 3:2. Perform vacuum degassing at a vacuum degree of -0.09 MPa for 15 min. After degassing is completed, transfer it to a light-proof and sealed container to obtain a high-adhesion and high-temperature-resistant UV adhesive.

[0049] Example 4

[0050] A preparation method of a high-adhesion and high-temperature-resistant UV adhesive, comprising the following steps:

[0051] (1) Ultrasonically disperse nano-silica in xylene. After dispersing evenly, add maleic anhydride. The mass ratio of nano-silica, xylene, and maleic anhydride is 100:5200:150. Stir and mix to react at a reaction temperature of 120 °C for 24 h. After the reaction is completed, perform suction filtration, wash with absolute ethanol and deionized water, and dry in vacuum at 60 °C for 24 h to obtain modified nano-silica;

[0052] (2) Mix epoxy soybean oil and the polymerization inhibitor 4-tert-butylcatechol evenly, heat them in an oil bath, and then add modified nano-silica and the catalyst dibutyltin dilaurate. The mass ratio of epoxy soybean oil, 4-tert-butylcatechol, modified nano-silica, and dibutyltin dilaurate is 100:0.5:48:0.6. Stir and mix, react at 120 °C for 4 h. After the reaction, cool, perform rotary evaporation, and vacuum dry at 60 °C for 6 h to obtain epoxy soybean oil acrylate modified silica;

[0053] (3) Mix phenolic resin and dimethylacetamide evenly, and then add methacryloxyethyl isocyanate, isocyanate-terminated polyurethane, and dibutyltin dilaurate. The mass ratio of phenolic resin, dimethylacetamide, methacryloxyethyl isocyanate, isocyanate-terminated polyurethane, and dibutyltin dilaurate is 100:1200:35:50:1.5. Stir and mix, react at 65 °C for 3 h. After the reaction, perform suction filtration, wash with acetone, and vacuum dry at 60 °C for 12 h to obtain vinylated phenolic resin modified polyurethane;

[0054] (4) Add acrylic acid, phenyl methacrylate, 2-hydroxyethyl methacrylate, polyethylene glycol diacrylate, 2-hydroxyethyl methacrylate phosphate, and isobornyl acrylate into a reactor, stir and mix for 40 min at a stirring speed of 200 r / min, then add epoxy soybean oil acrylate modified silica and stir for 60 min at a stirring rate of 400 r / min, then add vinylated phenolic resin modified polyurethane and stir for 30 min. After mixing evenly, add a photoinitiator and stir at a stirring rate of 100 r / min for 30 min. The mass ratio of acrylic acid, phenyl methacrylate, 2-hydroxyethyl methacrylate, polyethylene glycol diacrylate, 2-hydroxyethyl methacrylate phosphate, isobornyl acrylate, epoxy soybean oil acrylate modified silica, vinylated phenolic resin modified polyurethane, and photoinitiator is 42:50:28:16:10:7:15:100:3. The photoinitiator is composed of 1-hydroxycyclohexyl phenyl ketone and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide with a mass ratio of 3:2. Perform vacuum degassing at a vacuum degree of -0.1 MPa for 15 min. After the degassing is completed, transfer it to a light-proof and sealed container to obtain a high-adhesion and high-temperature-resistant UV adhesive.

[0055] Comparative Example 1

[0056] A preparation method of a UV adhesive, comprising the following steps:

[0057] (1) Mix the phenolic resin and dimethylacetamide evenly, then add methacryloyloxyethyl isocyanate, isocyanate-capped polyurethane, and diisobutyltin dilaurate. The mass ratio of phenolic resin, dimethylacetamide, methacryloyloxyethyl isocyanate, isocyanate-capped polyurethane, and diisobutyltin dilaurate is 100:1000:32:48:1.2. Stir and mix, react at 62 °C for 4 h. After the reaction is completed, perform suction filtration, wash with acetone, and dry in vacuum at 60 °C for 12 h to obtain vinylated phenolic resin-modified polyurethane;

[0058] (2) Add acrylic acid, phenyl methacrylate, 2-hydroxyethyl methacrylate, polyethylene glycol diacrylate, 2-hydroxyethyl methacrylate phosphate, and isobornyl acrylate to the reactor, stir and mix for 38 min at a stirring speed of 250 r / min. Then add epoxy soybean oil and nano-silica and stir for 50 min at a stirring rate of 450 r / min. Then add vinylated phenolic resin-modified polyurethane and stir for 28 min. After mixing evenly, add a photoinitiator and stir at a stirring rate of 120 r / min for 25 min. The mass ratio of acrylic acid, phenyl methacrylate, 2-hydroxyethyl methacrylate, polyethylene glycol diacrylate, 2-hydroxyethyl methacrylate phosphate, isobornyl acrylate, epoxy soybean oil, nano-silica, vinylated phenolic resin-modified polyurethane, and photoinitiator is 38:46:25:15:8:6:10:4:100:2.5. The photoinitiator is composed of 1-hydroxycyclohexyl phenyl ketone and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide with a mass ratio of 3:2. Perform vacuum degassing at a vacuum degree of -0.09 MPa for 15 min. After degassing is completed, transfer it to a light-shielded and sealed container to obtain the UV glue.

[0059] Comparative Example 2

[0060] A preparation method of a UV glue, comprising the following steps:

[0061] (1) Acrylic acid, ethyl methacrylate, methacrylic acid, and isobornyl acrylate were added to a reactor and stirred and mixed for 38 min at a stirring speed of 250 r / min. Then, epoxy soybean oil acrylate-modified silica was added and stirred for 50 min at a stirring rate of 450 r / min. Next, vinylated phenolic resin-modified polyurethane was added and stirred for 28 min. After mixing evenly, a photoinitiator was added and stirred at a stirring rate of 120 r / min for 25 min. Among them, the mass ratio of acrylic acid, ethyl methacrylate, methacrylic acid, isobornyl acrylate, epoxy soybean oil acrylate-modified silica, vinylated phenolic resin-modified polyurethane, and photoinitiator was 61:46:25:6:14:100:2.5. The photoinitiator was composed of 1-hydroxycyclohexyl phenyl ketone and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide with a mass ratio of 3:2. Vacuum degassing was carried out at a vacuum degree of -0.09 MPa for 15 min. After degassing was completed, it was transferred to a light-proof and sealed container to obtain a UV adhesive.

[0062] Among them, the preparation methods of epoxy soybean oil acrylate-modified silica and vinylated phenolic resin-modified polyurethane were the same as those of epoxy soybean oil acrylate-modified silica and vinylated phenolic resin-modified polyurethane in Example 3.

[0063] In this invention, the nano-silica used in the examples and comparative examples was purchased from Pengrui Chemical Co., Ltd., Lianyungang, Jiangsu, with a particle size of 15 nm; the epoxy soybean oil was purchased from Hangzhou Shuoya Oil Chemical Factory, with an epoxy value of 6.08; the phenolic resin was purchased from Jinan Shengquan Co., Ltd., with the brand number BR2123F; the polyethylene glycol diacrylate was purchased from Guangzhou Lihou Trading Co., Ltd.; the isocyanate-terminated polyurethane was prepared from isophorone diisocyanate and 2,2-dimethylolpropionic acid to obtain an isocyanate-terminated linear hydrophilic prepolymer; other raw materials and reagents not specified were commercially available.

[0064] The relevant performance tests were carried out on the UV adhesives prepared in Examples 1-4 and Comparative Examples 1-2, and the tests were as follows:

[0065] (1) Adhesion performance test: The test standard referred to GB / T 7124-2008 "Determination of Tensile Shear Strength of Adhesives (Rigid Material to Rigid Material)". Two identical rigid aluminum alloy plates were bonded together using the UV adhesives of Examples 1-4 and Comparative Examples 1-2 respectively, with a bonding area of 25 mm × 12.5 mm. The bonded specimens were cured under an ultraviolet lamp for 60 s at a wavelength of 365 nm to make them completely cured, and bonded specimens 1-6 were obtained respectively. A universal material testing machine was used to stretch the specimens at a stretching speed of 10 mm / min, and the maximum load at the time of specimen failure was recorded, and the bonding strength was calculated. Three groups were tested respectively, and the average value was taken;

[0066] (2) High-temperature resistance performance test

[0067] 1) Cure the UV glue. The curing conditions are curing for 60 s under an ultraviolet lamp with a wavelength of 365 nm. After the UV glue is cured, dry it in an 80 °C drying oven for 2 h to obtain a sample. Then grind the sample into powder with a particle size ≤ 100 μm and conduct thermogravimetric analysis. The test standard refers to ASTM E1131, and the test is carried out in a nitrogen atmosphere with a heating rate of 10 °C / min and a temperature range of 25 - 600 °C. Record the initial decomposition temperature T 5％ and the maximum decomposition temperature T max . The initial decomposition temperature is the temperature corresponding to a 5% weight loss. Test three groups respectively and take the average value;

[0068] 2) Place samples 1 - 6 in a high-temperature test chamber. The temperature of the high-temperature test chamber is 200 °C, the heating rate is 5 °C / min, keep the temperature for 4 h, cool to room temperature, take out and place for 30 min, then test the bonding performance and calculate the bonding strength. Test three groups respectively and take the average value;

[0069] The above test results are shown in Table 1:

[0070] Table 1

[0071]

[0072] According to the test results in Table 1, it can be seen that the UV glues corresponding to Examples 1 - 4 in the present invention have the characteristics of good adhesion and good high-temperature resistance performance. In Comparative Example 1, nano-silica was not modified, and nano-silica and epoxy soybean oil were directly added, resulting in poor dispersibility and poor compatibility between raw materials, leading to interface defects and low interface crosslinking degree, resulting in a significant reduction in bonding performance and a decrease in heat resistance performance. In Comparative Example 2, the benzene ring rigid structure is lacking, and the crosslinking density becomes poor, the heat resistance performance becomes poor, and it is prone to degradation at high temperatures, and the bonding performance is also significantly reduced.

[0073] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. All equivalent changes and improvements made within the scope of the present invention application shall still fall within the scope covered by the present invention.

Claims

1. A preparation method of a high-adhesion and high-temperature-resistant UV glue, characterized in that: It includes the following steps: Step 1: Ultrasonically disperse nano-silica into xylene. After uniform dispersion, add maleic anhydride, stir and mix to react. After the reaction is completed, filter by suction, wash, and dry to obtain modified nano-silica; Step 2: Mix epoxy soybean oil and inhibitor evenly, heat in an oil bath, then add modified nano-silica and catalyst, stir and mix to react. After the reaction is completed, cool, rotary evaporate, and dry to obtain epoxy soybean oil acrylate modified silica; Step 3: Mix phenolic resin and dimethylacetamide evenly, then add methacryloyloxyethyl isocyanate, isocyanate-terminated polyurethane, and diisobutyltin dilaurate, stir and mix to react. After the reaction is completed, filter by suction, wash, and dry to obtain vinylated phenolic resin modified polyurethane; Step 4: Stir and mix acrylic acid, phenyl methacrylate, 2-hydroxyethyl methacrylate, polyethylene glycol diacrylate, 2-hydroxyethyl methacrylate phosphate, isobornyl acrylate, epoxy soybean oil acrylate modified silica, vinylated phenolic resin modified polyurethane, and photoinitiator. After mixing evenly, carry out vacuum degassing to obtain a high-adhesion and high-temperature-resistant UV glue.

2. The preparation method of a high-adhesion and high-temperature resistant UV glue according to claim 1, characterized in that: In the said Step 1, the mass ratio of nano-silica, xylene, and maleic anhydride is 100:4800 - 5200:120 - 150.

3. The preparation method of a high-adhesion and high-temperature resistant UV glue according to claim 1, characterized in that: In the said Step 1, the reaction temperature is 110 - 120 °C, and the reaction time is 24 - 30 h.

4. The preparation method of a high-adhesion and high-temperature resistant UV glue according to claim 1, characterized in that: In the said Step 2, the mass ratio of epoxy soybean oil, inhibitor, modified nano-silica, and catalyst is 100:0.1 - 0.5:30 - 48:0.15 - 0.6, the reaction temperature is 115 - 120 °C, and the reaction time is 4 - 6 h.

5. The preparation method of a high-adhesion and high-temperature resistant UV glue according to claim 1, characterized in that: In the said Step 2, the catalyst is diisobutyltin dilaurate, and the inhibitor is 4-tert-butylcatechol.

6. The preparation method of a high-adhesion and high-temperature resistant UV glue according to claim 1, characterized in that: In the said Step 3, the mass ratio of phenolic resin, dimethylacetamide, methacryloyloxyethyl isocyanate, isocyanate-terminated polyurethane, and diisobutyltin dilaurate is 100:900 - 1200:22 - 35:40 - 50:0.5 - 1.5, the reaction temperature is 60 - 65 °C, and the reaction time is 3 - 5 h.

7. The preparation method of a high-adhesion and high-temperature resistant UV glue according to claim 1, characterized in that: The specific process for preparing the high-adhesion and high-temperature-resistant UV glue in Step 4 is as follows: Acrylic acid, phenyl methacrylate, 2-hydroxyethyl methacrylate, polyethylene glycol diacrylate, 2-hydroxyethyl methacrylate phosphate, isobornyl acrylate are added to a reactor and stirred and mixed for 30 - 40 min at a stirring speed of 200 - 300 r / min. Then, epoxy soybean oil acrylate-modified silica is added and stirred for 30 - 60 min at a stirring rate of 400 - 500 r / min. Next, vinylated phenolic resin-modified polyurethane is added and stirred for 20 - 30 min. After mixing evenly, a photoinitiator is added and stirred at a stirring rate of 100 - 150 r / min for 15 - 30 min. Vacuum degassing is carried out with a vacuum degree of -0.08 MPa to -0.1 MPa for 15 min. After the degassing is completed, it is transferred to a light-proof and sealed container to obtain the high-adhesion and high-temperature-resistant UV glue.

8. The preparation method of a high-adhesion and high-temperature resistant UV glue according to claim 1, characterized in that: In Step 4, the mass ratio of acrylic acid, phenyl methacrylate, 2-hydroxyethyl methacrylate, polyethylene glycol diacrylate, 2-hydroxyethyl methacrylate phosphate, isobornyl acrylate, epoxy soybean oil acrylate-modified silica, vinylated phenolic resin-modified polyurethane, and photoinitiator is 35 - 42:40 - 50:20 - 28:10 - 16:6 - 10:4 - 7:7 - 15:100:1 - 3.

9. The preparation method of a high-adhesion and high-temperature resistant UV glue according to claim 1, characterized in that: In Step 4, the photoinitiator is composed of 1-hydroxycyclohexyl phenyl ketone and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide with a mass ratio of 3:

2.

10. A high-adhesion and high-temperature-resistant UV glue prepared by the preparation method of the high-adhesion and high-temperature-resistant UV glue according to any one of claims 1 - 9.

Images