A heat-resistant flame-retardant adhesive and a preparation method thereof

Abstract

The present application relates to the technical field of adhesive, in particular to a heat-resistant flame-retardant adhesive and a preparation method thereof.A heat-resistant flame-retardant adhesive, according to parts by weight, its preparation raw materials include modified phenolic epoxy acrylate resin 40-60 parts, modified brominated epoxy acrylate resin 20-40 parts, toughening agent 3-8 parts, filler 1-3 parts, auxiliary thixotropic agent 0.3-1 part, coupling agent 0.5-2 parts, thermal initiator 0.5-2 parts.The heat-resistant flame-retardant adhesive prepared by the present application can obtain excellent corrosion resistance and lap shear performance, further enabling the adhesive to meet complex application environment.The heat-resistant flame-retardant adhesive prepared by the present application can obtain excellent flame retardant performance and temperature resistance.

Description

Technical Field

[0001] This invention relates to the field of adhesive technology, specifically to a heat-resistant and flame-retardant adhesive and its preparation method. Background Technology

[0002] In the traditional shipbuilding and repair industry, fastening methods such as riveting, bolting, and welding are commonly used. These methods are limited by factors such as material composition, shape, thickness, size, and hardness, and are prone to stress concentration, leading to damage to the ship's main structure, reducing its usability, and increasing maintenance costs. With the development and maturation of adhesive technology, adhesives are gradually replacing traditional fastening methods such as riveting, bolting, and welding. Because ships navigate complex and harsh environments such as rivers, lakes, and seas, with variable climates and frequent accidents, special requirements are placed on adhesives, such as resistance to seawater, atmospheric aging, oil, extreme temperature fluctuations, flame retardancy, and vibration.

[0003] Epoxy vinyl ester resins have vinyl ester groups at both ends of their molecules, with an epoxy resin backbone in the middle. They are obtained by ring-opening esterification reaction between unsaturated organic monocarboxylic acids and epoxy resins. Epoxy vinyl ester resins combine the excellent corrosion resistance and mechanical properties of epoxy resins with the easy processing and molding properties of unsaturated polyester resins, making them widely used in the shipbuilding industry. Chinese patent application number CN201310289458.9 discloses a single-component UV-anaerobic dual-curing adhesive, listing the use of phenolic epoxy acrylate resin to solve the problem of incomplete curing of UV-cured adhesives in shaded areas.

[0004] The purpose of this invention is to provide a high-temperature resistant adhesive using epoxy vinyl resin as the main component, in order to solve the problems of poor heat resistance, flame retardancy, and weather resistance of the existing marine adhesives. Summary of the Invention

[0005] To address the above problems, the first aspect of this invention provides a heat-resistant and flame-retardant adhesive, which, by weight, comprises 40-60 parts of modified phenolic epoxy acrylate resin, 20-40 parts of modified brominated epoxy acrylate resin, 3-8 parts of toughening agent, 1-3 parts of filler, 0.3-1 parts of thixotropic agent, 0.5-2 parts of coupling agent, and 0.5-2 parts of thermal initiator.

[0006] Preferably, the method for preparing the modified phenolic epoxy acrylate resin, by weight, includes the following steps:

[0007] Phenolic epoxy resin and brominated bisphenol A undergo a ring-opening reaction at 165-175℃ under the action of a catalyst. The temperature is then lowered to 115-125℃, and methacrylic acid and maleic anhydride are added. Under the action of polymerization inhibitor a and catalyst, the temperature is lowered until the acid value is less than 11 mg KOH / g. The temperature is then lowered to 75-85℃, and polymerization inhibitor b and solvent are added. After stirring, modified phenolic epoxy acrylate resin is obtained.

[0008] The acid value was tested according to the standard method of GB / T 6743-2008.

[0009] Furthermore, the method for preparing the modified phenolic epoxy acrylate resin includes the following steps:

[0010] Phenolic epoxy resin and brominated bisphenol A undergo a ring-opening reaction at 165-175℃ under the action of a catalyst. The temperature is then lowered to 115-125℃, and methacrylic acid and maleic anhydride are added. Under the action of polymerization inhibitor a and catalyst, the temperature is lowered until the acid value is less than 11 mg KOH / g. The temperature is then lowered to 75-85℃, and polymerization inhibitor b and styrene are added. After stirring, modified phenolic epoxy acrylate resin is obtained.

[0011] Preferably, the phenolic epoxy resin is selected from one or more of the following: heat-resistant phenolic epoxy resin F-44, heat-resistant phenolic epoxy resin F-48, heat-resistant phenolic epoxy resin F-51, and heat-resistant phenolic epoxy resin F-53.

[0012] Preferably, the CAS number of the brominated bisphenol A is 79-94-7.

[0013] Preferably, the CAS number of the methacrylic acid is 79-41-4.

[0014] Preferably, the maleic anhydride has a CAS number of 108-31-6.

[0015] Preferably, the polymerization inhibitor a is selected from one or more of hydroquinone, p-tert-butylcatechol, benzoquinone, methylhydroquinone, di-tert-butyl-p-cresol, 2,5-di-tert-butylhydroquinone, 2,5-di-tert-butyl-p-cresol, and phenothiazine.

[0016] Preferably, the polymerization inhibitor b is selected from one or more of hydroquinone, p-tert-butylcatechol, benzoquinone, methylhydroquinone, di-tert-butyl-p-cresol, 2,5-di-tert-butylhydroquinone, 2,5-di-tert-butyl-p-cresol, and phenothiazine.

[0017] Preferably, the catalyst is selected from one or more of benzyltrimethylammonium chloride, benzyltriethylammonium chloride, tetrabutylammonium chloride, and methylpyridine.

[0018] Preferably, the raw materials for preparing the modified brominated epoxy acrylate resin, by weight, include 32-38 parts of base epoxy resin, 21-23 parts of brominated epoxy resin, 17-22 parts of unsaturated carboxylic acid, 4-8 parts of flame retardant, 25-30 parts of solvent, 0.1-0.3 parts of catalyst, and 0.01-0.05 parts of polymerization inhibitor c.

[0019] Preferably, the epoxy equivalent of the base epoxy resin is between 180-210 g / mol, including any one or any mixture of two or more of bisphenol A type epoxy resin, bisphenol S type epoxy resin, bisphenol F type epoxy resin, polyethylene glycol diglycidyl ether and polypropylene glycol diglycidyl ether.

[0020] Preferably, the unsaturated carboxylic acid is selected from one or more of fumaric acid, acrylic acid, methacrylic acid, and maleic acid.

[0021] Furthermore, the solvent is styrene.

[0022] Preferably, the unsaturated carboxylic acid is fumaric acid and methacrylic acid, and the mass ratio of fumaric acid to methacrylic acid is 1:(2-3).

[0023] Furthermore, the flame retardant is trichloroethyl phosphate.

[0024] Further, the polymerization inhibitor c is selected from one or more of hydroquinone, benzoquinone, p-tert-butylcatechol, methylhydroquinone, di-tert-butyl-p-cresol, 2,5-di-tert-butylhydroquinone, 2,5-di-tert-butyl-p-cresol, and phenothiazine.

[0025] Further, the polymerization inhibitor is a mixture of p-tert-butylcatechol and hydroquinone, wherein the mass ratio of p-tert-butylcatechol to hydroquinone is 1:(0.6-0.9).

[0026] Furthermore, the catalyst is selected from one or more of benzyltrimethylammonium chloride, benzyltriethylammonium chloride, tetrabutylammonium chloride, and methylpyridine.

[0027] Furthermore, the catalyst is benzyltrimethylammonium chloride.

[0028] Preferably, the brominated epoxy resin has an epoxy value of 0.235-0.255 mol / 100g and a bromine mass fraction of 49.5-53%.

[0029] Furthermore, the raw materials for preparing the modified brominated epoxy acrylate resin include a base epoxy resin, a brominated epoxy resin, fumaric acid, methacrylic acid, trichloroethyl phosphate, styrene, benzyltrimethylammonium chloride, hydroquinone, and p-tert-butylcatechol.

[0030] Furthermore, the preparation method of the modified brominated epoxy acrylate resin includes the following steps:

[0031] In a reaction flask equipped with a thermometer, stirrer, and reflux condenser, the base epoxy resin and brominated epoxy resin are added sequentially. The mixture is stirred at 60°C for 10-15 minutes. After thorough mixing, hydroquinone is added, followed by fumaric acid, 1 / 2 part by weight of methacrylic acid, and 1 / 2 part by weight of benzyltrimethylammonium chloride. The temperature is gradually increased to 110°C, and the reaction is carried out for 1 hour. After this, 1 / 2 part by weight of methacrylic acid and 1 / 2 part by weight of benzyltrimethylammonium chloride are added. Once the addition is complete, the stirring is started, and the reaction temperature is gradually increased to 120-125°C for 4 hours. When the acid value is less than 16 mg KOH / g, the temperature is lowered. When the temperature drops to 80°C, p-tert-butylcatechol, trichloroethyl phosphate, and styrene are added, and the mixture is stirred until it reaches 50°C. The modified brominated epoxy acrylate resin is then discharged.

[0032] To improve the flame retardancy and temperature resistance of heat-resistant and flame-retardant adhesives, the inventors discovered during experiments that using modified phenolic epoxy acrylate resin and modified brominated epoxy acrylate resin in combination has a good synergistic effect, which can further improve the flame retardancy and temperature resistance of the heat-resistant and flame-retardant adhesives. This may be because the modified brominated epoxy acrylate resin is prepared using specific raw materials, including brominated epoxy resin with an epoxy value of 0.235-0.255 mol / 100g and a bromine content of 49.5-53%. This allows the modified brominated epoxy acrylate resin to act as a reactive flame-retardant resin, with a molecular structure based on brominated epoxy, giving the resin high flame-retardant properties, achieving a limiting oxygen index of 36%, and a high glass transition temperature (Tg) of 145℃.

[0033] Preferably, the toughening agent is hydroxypropyl methacrylate-modified polyurethane.

[0034] Preferably, the preparation method of the hydroxypropyl methacrylate modified polyurethane includes the following steps:

[0035] Polyester polyol, isocyanate and monofunctional acrylate are reacted at 65-80℃ in the presence of a catalyst until NCO drops to 0. Then, the temperature is lowered to 50℃, and polymerization inhibitor d and acrylate diluent are added. After stirring, hydroxypropyl methacrylate modified polyurethane is prepared.

[0036] The NCO refers to the isocyanate group in the chemical material, and its value refers to the mass of isocyanate (-NCO) groups contained in 100g of sample.

[0037] Preferably, the polyester polyol is selected from one or more of adipic acid-1,4-butanediol, adipic acid-neopentyl glycol, and phthalic acid-diethylene glycol.

[0038] Preferably, the isocyanate is one or more of HDI, HMDI, IPDI, TDI, and MDI.

[0039] Preferably, the monofunctional acrylate is selected from one or more of hydroxypropyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, and hydroxyethyl acrylate.

[0040] Preferably, the catalyst is selected from one or more of dimethylaminoethanol, dibutyltin dilaurate, triethylamine, triethanolamine, and N,N-dimethylbenzylamine.

[0041] Preferably, the polymerization inhibitor d is selected from one or more of p-methylhydroquinone, benzoquinone, hydroquinone, di-tert-butyl-p-cresol, p-tert-butylcatechol, 2,5-di-tert-butyl-p-cresol, 2,5-di-tert-butyl-p-cresol, and phenothiazine.

[0042] Preferably, the acrylate diluent is selected from one or more of the following: hydroxypropyl methacrylate, hydroxyethyl methacrylate, 2-methyl-1,3-propanediol diacrylate, 3-methyl-1,5-pentanediol diacrylate, hydroxypropyl acrylate, hydroxyethyl acrylate, isobornyl acrylate, ethylene glycol dimethacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, tripropylene glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, ethoxylated trimethylolpropane trimethacrylate, ethoxylated pentaerythritol tetraacrylate, propoxylated glycerol triacrylate, and neopentyl glycol diacrylate.

[0043] To improve the corrosion resistance and lap shear properties of adhesives, and further enable them to meet the requirements of complex application environments, the inventors discovered during experiments that by using adhesives with a specific surface area of ​​175–225 m² / g, [the following method can be achieved]. 2 The combined use of fumed silica (g / g) with toughening agents such as hydroxypropyl methacrylate-modified polyurethane, modified phenolic epoxy acrylate resin, and modified brominated epoxy acrylate resin can improve the corrosion resistance and lap shear properties of adhesives. This is achieved through the interaction of functional groups in the hydroxypropyl methacrylate-modified polyurethane, modified phenolic epoxy acrylate resin, and modified brominated epoxy acrylate resin, which create an interactive network structure and further enhance the surface area of ​​the adhesive (175–225 m² / g). 2 / g of fumed silica encapsulated in an interactive network structure can further improve the corrosion resistance and lap shear properties of adhesives, meeting the requirements of complex application environments.

[0044] Preferably, the specific surface area of ​​the filler is 175–225 m². 2 / g.

[0045] Preferably, the filler is fumed silica.

[0046] Preferably, the thixotropic agent is BYK 605.

[0047] Preferably, the thixotropic agent is purchased from BYK, Germany, and the model number is BYK 605.

[0048] Preferably, the coupling agent is selected from one or more of methyltrimethoxysilane, vinyltrichlorosilane, r-(methacryloyloxy)propyltrimethoxysilane, maleic anamidopropyltriethoxysilane, and aminoethylaminopropyltrimethoxysilane.

[0049] Furthermore, the coupling agent is methyltrimethoxysilane.

[0050] Preferably, the thermal initiator is selected from one or more of methyl ethyl ketone peroxide, tert-butyl peroxide, benzoyl peroxide, cumene hydroperoxide, azobisisobutyronitrile, tert-butyl peroxide-3,5,5-trimethylhexanoate, and azobisisoheptanenitrile.

[0051] Preferably, the thermal initiator is tert-butyl peroxide and / or benzoyl peroxide.

[0052] A second aspect of this invention provides a method for preparing a heat-resistant and flame-retardant adhesive, comprising the following steps:

[0053] Modified phenolic epoxy acrylate resin and modified brominated epoxy acrylate resin are added to a reactor and stirred at 800 rpm for 3-5 minutes. Then, toughening agent is added and stirred at 800 rpm for 3-5 minutes. After adding coupling agent, stirring is continued at 800 rpm for 3-5 minutes. The stirring speed is reduced to 600 rpm, filler and thixotropic agent are added, and the stirring speed is increased to 1500 rpm. The mixture is stirred for 10-15 minutes, then the stirring speed is reduced to 600 rpm, thermal initiator is added, and the stirring speed is increased to 1500 rpm. The mixture is stirred for 5 minutes to obtain a heat-resistant and flame-retardant adhesive.

[0054] Further, the preparation method of the heat-resistant and flame-retardant adhesive includes the following steps: adding modified phenolic epoxy acrylate resin and modified brominated epoxy acrylate resin to a reactor, stirring at 800 rpm for 3-5 min, then adding a toughening agent, stirring at 800 rpm for 3-5 min, adding a modified coupling agent, and stirring at 800 rpm for 3-5 min; reducing the stirring speed to 600 rpm, adding fumed silica and thixotropic agent BYK 605, increasing the speed to 1500 rpm, stirring for 10-15 min, reducing the speed to 600 rpm, adding a thermal initiator, increasing the stirring speed to 1500 rpm, and stirring for 5 min to obtain the heat-resistant and flame-retardant adhesive.

[0055] Beneficial effects

[0056] The heat-resistant and flame-retardant adhesive prepared by this invention can achieve excellent flame-retardant and temperature-resistant properties.

[0057] The heat-resistant and flame-retardant adhesive prepared by this invention can achieve excellent corrosion resistance and lap shear properties, further enabling the adhesive to meet complex application environments.

[0058] The modified brominated epoxy acrylate resin prepared by this invention can be used as a reactive flame retardant resin. Its molecular structure skeleton is brominated epoxy, which endows the resin with high flame retardant properties, a limiting oxygen index of 36%, and a high glass transition temperature (Tg) of 145℃.

[0059] The heat-resistant and flame-retardant adhesive prepared by this invention exhibits excellent high-temperature resistance and flame retardancy, with a glass transition temperature (Tg) as high as 195℃ and a limiting oxygen index of 34.5%. Furthermore, the heat-resistant and flame-retardant adhesive prepared in this application has a tensile shear strength exceeding 15.5 MPa and good adhesive strength. Detailed Implementation

[0060] Example 1

[0061] A raw material for preparing a modified brominated epoxy acrylate resin, by weight, comprises 33.709 parts of base epoxy resin, 21.505 parts of brominated epoxy resin, 6.303 parts of fumaric acid, 14.358 parts of methacrylic acid, 6.8 parts of trichloroethyl phosphate, 26 parts of styrene, 0.205 parts of benzyltrimethylammonium chloride, 0.015 parts of hydroquinone, and 0.02 parts of p-tert-butylcatechol.

[0062] The base epoxy resin was purchased from Nan Ya Plastics Industrial Co., Ltd., and is a bisphenol A type epoxy resin with an epoxy equivalent between 180-210 g / mol.

[0063] The brominated epoxy resin has an epoxy value of 0.235-0.255 mol / 100g and a bromine mass fraction of 49.5-53%.

[0064] The CAS number of the fumaric acid is 110-17-8.

[0065] The CAS number of the methacrylic acid is 79-41-4.

[0066] The CAS number for the trichloroethyl phosphate is 115-96-8.

[0067] The CAS number for the styrene is 100-42-5.

[0068] The CAS number of the benzyltrimethylammonium chloride is 56-93-9.

[0069] The CAS number of the hydroquinone is 123-31-9.

[0070] The CAS number for p-tert-butylcatechol is 98-29-3.

[0071] The preparation method of the modified brominated epoxy acrylate resin includes the following steps:

[0072] In a reaction flask equipped with a thermometer, stirrer, and reflux condenser, base epoxy resin and brominated epoxy resin were added sequentially. The mixture was stirred at 60°C for 10 minutes. After thorough mixing, hydroquinone was added, followed by fumaric acid, 1 / 2 part by weight of methacrylic acid, and 1 / 2 part by weight of benzyltrimethylammonium chloride. The temperature was gradually increased to 110°C, and the reaction was allowed to proceed for 1 hour. After this, 1 / 2 part by weight of methacrylic acid and 1 / 2 part by weight of benzyltrimethylammonium chloride were added. Once the addition was complete, the stirring was started, and the reaction temperature was gradually increased to 120°C for 4 hours. When the acid value was less than 16 mg KOH / g, the temperature was lowered. When the temperature dropped to 80°C, p-tert-butylcatechol, trichloroethyl phosphate, and styrene were added, and the mixture was stirred until it reached 50°C. The modified brominated epoxy acrylate resin was then discharged.

[0073] Example 2

[0074] This embodiment provides a method for preparing modified phenolic epoxy acrylate resin, including the following steps:

[0075] By weight, 70 parts of phenolic epoxy resin and 18 parts of brominated bisphenol A were subjected to a ring-opening reaction at 170°C under the action of 0.028 parts of catalyst. The temperature was then lowered to 120°C, and 18 parts of methacrylic acid and 1 part of maleic anhydride were added. Under the action of 0.012 parts of polymerization inhibitor and 0.35 parts of catalyst, the temperature was lowered when the acid value was less than 11 mg KOH / g. The temperature was then lowered to 80°C, and 0.022 parts of polymerization inhibitor and 30 parts of styrene were added and stirred to obtain the modified phenolic epoxy acrylate resin.

[0076] The phenolic epoxy resin is heat-resistant phenolic epoxy resin F-48.

[0077] The heat-resistant phenolic epoxy resin F-48 can be purchased from Nan Ya Plastics Industrial Co., Ltd.

[0078] The CAS number of the brominated bisphenol A is 79-94-7.

[0079] The CAS number of the methacrylic acid is 79-41-4.

[0080] The CAS number of the maleic anhydride is 108-31-6.

[0081] The polymerization inhibitor is hydroquinone.

[0082] The CAS number of the hydroquinone is 123-31-9.

[0083] The catalyst is benzyltrimethylammonium chloride.

[0084] The CAS number of the benzyltrimethylammonium chloride is 56-93-9.

[0085] Example 3

[0086] This embodiment provides a method for preparing polyurethane modified with toughening agent hydroxypropyl methacrylate, including the following steps:

[0087] By weight, 67 parts of polyester polyol, 20 parts of isocyanate and 15 parts of monofunctional acrylate were reacted at 70°C with 0.008 parts of catalyst until NCO dropped to 0. Then, the temperature was lowered to 50°C. After that, 0.046 parts of polymerization inhibitor and 10 parts of acrylate diluent were added and stirred to prepare hydroxypropyl methacrylate modified polyurethane.

[0088] The polyester polyol is adipic acid-neopentyl glycol.

[0089] The isocyanate was purchased from Yantai Wanhua, and its model was HDI.

[0090] The monofunctional acrylate is hydroxypropyl methacrylate.

[0091] The catalyst is dibutyltin dilaurate.

[0092] The polymerization inhibitor is hydroquinone.

[0093] The acrylate diluent is dipropylene glycol diacrylate.

[0094] Example 4

[0095] The first aspect of this embodiment provides a heat-resistant and flame-retardant adhesive, which, by weight, comprises 60 parts of modified phenolic epoxy acrylate resin, 20 parts of modified brominated epoxy acrylate resin, 6 parts of toughening agent, 2 parts of filler, 0.8 parts of thixotropic agent, 0.8 parts of coupling agent, and 1 part of thermal initiator.

[0096] The modified brominated epoxy acrylate resin is the modified brominated epoxy acrylate resin prepared in Example 1.

[0097] The modified phenolic epoxy acrylate resin is the modified phenolic epoxy acrylate resin prepared in Example 2.

[0098] The toughening agent is the hydroxypropyl methacrylate-modified polyurethane prepared in Example 3.

[0099] The filler is fumed silica.

[0100] The specific surface area of ​​the fumed silica is 175–225 m². 2 / g.

[0101] The thixotropic agent was purchased from BYK, Germany, and its model number is BYK 605.

[0102] The coupling agent is methyltrimethoxysilane.

[0103] The CAS number of the methyltrimethoxysilane is 1185-55-3.

[0104] The thermal initiator is tert-butyl peroxide.

[0105] The CAS number of the tert-butyl peroxide is 614-45-9.

[0106] The second aspect of this embodiment provides a method for preparing a heat-resistant and flame-retardant adhesive, comprising the following steps:

[0107] Modified phenolic epoxy acrylate resin and modified brominated epoxy acrylate resin were added to a reactor and stirred at 800 rpm for 3 minutes. Then, a toughening agent was added and stirred at 800 rpm for 3 minutes. After adding a coupling agent, the mixture was stirred at 800 rpm for 3 minutes. The stirring speed was reduced to 600 rpm, filler and thixotropic agent were added, and the stirring speed was increased to 1500 rpm for 10 minutes. The stirring speed was reduced to 600 rpm, a thermal initiator was added, and the stirring speed was increased to 1500 rpm for 5 minutes to obtain a heat-resistant and flame-retardant adhesive.

[0108] Example 5

[0109] The first aspect of this embodiment provides a heat-resistant and flame-retardant adhesive, which, by weight, comprises 60 parts of modified phenolic epoxy acrylate resin, 40 parts of modified brominated epoxy acrylate resin, 5 parts of toughening agent, 1.8 parts of filler, 0.5 parts of thixotropic agent, 0.8 parts of coupling agent, and 2 parts of thermal initiator.

[0110] The modified brominated epoxy acrylate resin is the modified brominated epoxy acrylate resin prepared in Example 1.

[0111] The modified phenolic epoxy acrylate resin is the modified phenolic epoxy acrylate resin prepared in Example 2.

[0112] The toughening agent is the hydroxypropyl methacrylate-modified polyurethane prepared in Example 3.

[0113] The filler is fumed silica.

[0114] The specific surface area of ​​the fumed silica is 175–225 m². 2 / g.

[0115] The thixotropic agent was purchased from BYK, Germany, and its model number is BYK 605.

[0116] The coupling agent is methyltrimethoxysilane.

[0117] The CAS number of the methyltrimethoxysilane is 1185-55-3.

[0118] The thermal initiator is benzoyl peroxide.

[0119] The CAS number of the benzoyl peroxide is 94-36-0.

[0120] The second aspect of this embodiment provides a method for preparing a heat-resistant and flame-retardant adhesive, comprising the following steps:

[0121] Modified phenolic epoxy acrylate resin and modified brominated epoxy acrylate resin were added to a reactor and stirred at 800 rpm for 3 minutes. Then, a toughening agent was added and stirred at 800 rpm for 3 minutes. After adding a coupling agent, the mixture was stirred at 800 rpm for 3 minutes. The stirring speed was reduced to 600 rpm, filler and thixotropic agent were added, and the stirring speed was increased to 1500 rpm for 10 minutes. The stirring speed was reduced to 600 rpm, a thermal initiator was added, and the stirring speed was increased to 1500 rpm for 5 minutes to obtain a heat-resistant and flame-retardant adhesive.

[0122] Example 6

[0123] The first aspect of this embodiment provides a heat-resistant and flame-retardant adhesive, which, by weight, comprises 40 parts of modified phenolic epoxy acrylate resin, 40 parts of modified brominated epoxy acrylate resin, 3 parts of toughening agent, 2 parts of filler, 0.8 parts of thixotropic agent, 0.8 parts of coupling agent, and 1.6 parts of thermal initiator.

[0124] The modified brominated epoxy acrylate resin is the modified brominated epoxy acrylate resin prepared in Example 1.

[0125] The modified phenolic epoxy acrylate resin is the modified phenolic epoxy acrylate resin prepared in Example 2.

[0126] The toughening agent is the hydroxypropyl methacrylate-modified polyurethane prepared in Example 3.

[0127] The filler is fumed silica.

[0128] The specific surface area of ​​the fumed silica is 175–225 m². 2 / g.

[0129] The thixotropic agent was purchased from BYK, Germany, and its model number is BYK 605.

[0130] The coupling agent is methyltrimethoxysilane.

[0131] The CAS number of the methyltrimethoxysilane is 1185-55-3.

[0132] The thermal initiator is benzoyl peroxide.

[0133] The CAS number of the benzoyl peroxide is 94-36-0.

[0134] The second aspect of this embodiment provides a method for preparing a heat-resistant and flame-retardant adhesive, comprising the following steps:

[0135] Modified phenolic epoxy acrylate resin and modified brominated epoxy acrylate resin were added to a reactor and stirred at 800 rpm for 3 minutes. Then, a toughening agent was added and stirred at 800 rpm for 3 minutes. After adding a coupling agent, the mixture was stirred at 800 rpm for 3 minutes. The stirring speed was reduced to 600 rpm, filler and thixotropic agent were added, and the stirring speed was increased to 1500 rpm for 10 minutes. The stirring speed was reduced to 600 rpm, a thermal initiator was added, and the stirring speed was increased to 1500 rpm for 5 minutes to obtain a heat-resistant and flame-retardant adhesive.

[0136] Comparative Example 1

[0137] This embodiment provides a flame-retardant epoxy vinyl ester adhesive, which, by weight, comprises 100 parts of flame-retardant epoxy vinyl ester resin, 2 parts of filler, 0.8 parts of thixotropic agent, 0.8 parts of coupling agent, and 2 parts of thermal initiator.

[0138] The raw materials for preparing the flame-retardant epoxy vinyl ester resin, by weight, include 100 parts of bisphenol A epoxy resin, 20 parts of methacrylic acid, 30 parts of styrene, 0.05 parts of hydroquinone, and 0.36 parts of benzyltrimethylammonium chloride.

[0139] The preparation method of the raw material for the flame-retardant epoxy vinyl ester resin includes the following steps: bisphenol A epoxy resin and methacrylic acid are added to a reaction vessel, heated to 60°C and stirred for 10 minutes. After stirring evenly, hydroquinone and benzyltrimethylammonium chloride are added, and the temperature is gradually increased to 120°C. The reaction is carried out for about 3 hours. When the acid value is less than 25 mg KOH / g, the temperature is lowered. When the temperature drops to 80°C, styrene is added and the stirring is continued until 50°C. The flame-retardant epoxy vinyl ester resin is then discharged.

[0140] The bromine mass fraction of the bisphenol A epoxy resin is 46-50%.

[0141] The bisphenol A epoxy resin was purchased from Nan Ya Plastics Industrial Co., Ltd.

[0142] The filler is fumed silica.

[0143] The specific surface area of ​​the fumed silica is 175–225 m² / g.

[0144] The thixotropic agent was purchased from BYK, Germany, and its model number is BYK 605.

[0145] The coupling agent is methyltrimethoxysilane.

[0146] The CAS number of the methyltrimethoxysilane is 1185-55-3.

[0147] The thermal initiator is benzoyl peroxide.

[0148] The CAS number of the benzoyl peroxide is 94-36-0.

[0149] This embodiment provides a method for preparing a flame-retardant epoxy vinyl ester adhesive, comprising the following steps: adding flame-retardant epoxy vinyl ester resin and methyltrimethoxysilane to a reactor, adding fumed silica and a thixotropic agent, stirring at 1500 rpm for 10 minutes, reducing the stirring speed to 600 rpm, adding benzoyl peroxide, increasing the stirring speed to 1500 rpm, and stirring for 5 minutes to obtain the flame-retardant epoxy vinyl ester adhesive.

[0150] Comparative Example 2

[0151] This embodiment provides a high-temperature resistant phenolic vinyl ester adhesive, which, by weight, comprises 100 parts of high-temperature resistant phenolic vinyl ester resin, 2 parts of filler, 0.8 parts of thixotropic agent, 0.8 parts of coupling agent, and 2 parts of thermal initiator.

[0152] The raw materials for preparing the high-temperature resistant phenolic vinyl ester resin, by weight, include 40 parts of phenolic epoxy resin F-513, 150 parts of methacrylic acid, 150 parts of styrene, 0.15 parts of hydroquinone, 1.2 parts of benzyltrimethylammonium chloride, and 0.05 parts of tert-butylcatechol.

[0153] The phenolic epoxy resin F-51 was purchased from Nan Ya Plastics Industrial Co., Ltd.

[0154] The method for preparing the high-temperature resistant phenolic vinyl ester resin includes the following steps: phenolic epoxy resin F-51, methacrylic acid, hydroquinone, and benzyltrimethylammonium chloride in the above-mentioned amounts are added to a reactor, and the temperature is gradually raised to 120°C under nitrogen gas. The temperature is maintained until the acid value test is less than 30 mg KOH / g. The temperature is then lowered to 100°C, tert-butylcatechol and styrene are added, and the mixture is stirred thoroughly. Finally, the temperature is cooled to 25°C to obtain the high-temperature resistant phenolic vinyl ester resin.

[0155] The filler is fumed silica.

[0156] The specific surface area of ​​the fumed silica is 175–225 m². 2 / g.

[0157] The thixotropic agent was purchased from BYK, Germany, and its model number is BYK 605.

[0158] The coupling agent is methyltrimethoxysilane.

[0159] The CAS number of the methyltrimethoxysilane is 1185-55-3.

[0160] The thermal initiator is benzoyl peroxide.

[0161] The CAS number of the benzoyl peroxide is 94-36-0.

[0162] This embodiment provides a method for preparing a high-temperature resistant phenolic vinyl adhesive, comprising the following steps: adding high-temperature resistant phenolic vinyl resin to a reactor, adding filler and thixotropic agent, stirring at 1500 rpm for 10 min, reducing the stirring speed to 600 rpm, adding a thermal initiator, increasing the stirring speed to 1500 rpm, stirring for 5 min, and obtaining the high-temperature resistant phenolic vinyl adhesive.

[0163] Performance testing

[0164] 1. Test the mechanical properties, thermal distortion properties, and flame retardant properties of the modified brominated epoxy acrylate resin.

[0165] Ten portions of the modified brominated epoxy acrylate resin prepared in Example 1 were tested. The maximum and minimum values ​​were removed, and the average value was taken. The test results are shown in Table 1.

[0166] II. Test the mechanical properties, thermal distortion properties, and flame retardant properties of the adhesive.

[0167] Ten portions of each adhesive prepared in Examples 4-6 and Comparative Examples 1-2 were tested. The maximum and minimum values ​​were removed, and the average value was taken. The test results are shown in Table 2.

[0168] III. Testing the chemical aging resistance of heat-resistant and flame-retardant adhesives.

[0169] The heat-resistant and flame-retardant adhesives prepared in Examples 4-6 were soaked in different chemical media for different times, and the initial strength retention rate after soaking was tested. The test results are shown in Table 3.

[0170] Table 1

[0171] Test Project Example 1 Test Standards Tensile strength / MPa 84.3 GB / T 2567-2021 Tensile modulus / MPa 3550 GB / T 2567-2021 Elongation at break / % 4.0％ GB / T 2567-2021 Bending strength / MPa 135 GB / T 2567-2021 Flexural modulus / MPa 3610 GB / T 2567-2021 Glass transition temperature (Tg) / ℃ 145 GB / T 1634-2019 Oxygen Index 36％ GB / T 2406.2-2009

[0172] The test results in Table 1 show that the modified brominated epoxy acrylate resin prepared in this application is a reactive flame retardant resin with a brominated epoxy molecular structure, which gives the resin high flame retardant properties, a limiting oxygen index of 36%, and a high glass transition temperature (Tg) of 145℃.

[0173] Table 2

[0174]

[0175] The test results in Table 2 show that the heat-resistant and flame-retardant adhesive prepared in this application has excellent high-temperature resistance and flame retardancy, with a glass transition temperature (Tg) of 195℃ and a limiting oxygen index of 34.5%. Furthermore, the heat-resistant and flame-retardant adhesive prepared in this application has a tensile shear strength exceeding 15.5 MPa and good bonding strength.

[0176] Table 3

[0177]

[0178] As can be seen from the test results in Table 3, the heat-resistant and flame-retardant adhesive prepared in this application has excellent corrosion resistance and a high strength retention rate.

Claims

1. A heat resistant flame retardant adhesive, characterized by, The raw materials for preparing the modified phenolic epoxy acrylate resin include 40-60 parts by weight of modified phenolic epoxy acrylate resin, 20-40 parts by weight of modified brominated epoxy acrylate resin, 3-8 parts by weight of toughening agent, 1-3 parts by weight of filler, 0.3-1 part by weight of auxiliary thixotropic agent, 0.5-2 parts by weight of coupling agent, and 0.5-2 parts by weight of thermal initiator; The preparation method of the modified phenolic epoxy acrylate resin comprises the following steps: The phenolic epoxy resin and the brominated bisphenol A are subjected to ring-opening reaction at 165-175℃ under the action of a catalyst, methyl methacrylate and maleic anhydride are added after cooling to 115-125℃, and the acid value is less than 11 mgKOH / g, and the temperature is lowered to 75-85℃ under the action of a polymerization inhibitor a and a catalyst, and the modified phenolic epoxy acrylate resin is obtained after stirring with a solvent; The raw materials for preparing the modified brominated epoxy acrylate resin include 32-38 parts by weight of base epoxy resin, 21-23 parts by weight of brominated epoxy resin, 17-22 parts by weight of unsaturated carboxylic acid, 4-8 parts by weight of flame retardant, 25-30 parts by weight of solvent, 0.1-0.3 parts by weight of catalyst, and 0.01-0.05 parts by weight of polymerization inhibitor c; The brominated epoxy resin has an epoxy value of 0.235-0.255 mol / 100g and a bromine element mass fraction of 49.5-53%; The toughening agent is hydroxypropyl methacrylate modified polyurethane; The preparation method of the hydroxypropyl methacrylate modified polyurethane comprises the following steps: The polyol, isocyanate and hydroxypropyl methacrylate are reacted at 65-80℃ under the action of a catalyst until the NCO content is reduced to 0, the temperature is lowered, and the hydroxypropyl methacrylate modified polyurethane is prepared after adding polymerization inhibitor d and acrylate diluent and stirring; The filler is fumed silica, the specific surface area of the filler is 175-225 m 2 / g.

2. The heat resistant flame retardant adhesive according to claim 1, wherein The unsaturated carboxylic acid is selected from one or more of acrylic acid or methacrylic acid, and one or more of fumaric acid or maleic acid.

3. The heat resistant flame retardant adhesive according to claim 1, wherein The unsaturated carboxylic acid is fumaric acid and methacrylic acid, and the mass ratio of the fumaric acid to the methacrylic acid is 1:(2-3).

4. A process for the preparation of heat resistant flame retardant adhesive as claimed in any one of claims 1 to 3, wherein the process comprises of the steps of: The following steps are included: The modified phenolic epoxy acrylate resin and the modified brominated epoxy acrylate resin are added to a reactor and stirred at a speed of 800 rpm for 3-5 min, the toughening agent is then added and stirred at a speed of 800 rpm for 3-5 min, the coupling agent is then added and stirred at a speed of 800 rpm for 3-5 min, the stirring speed is then lowered to 600 rpm, the filler and the auxiliary thixotropic agent are added, the stirring speed is then increased to 1500 rpm and stirred for 10-15 min, the stirring speed is then lowered to 600 rpm, the thermal initiator is added, the stirring speed is then increased to 1500 rpm and stirred for 5 min, and the heat-resistant and flame-retardant adhesive is obtained.

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