Compound accelerator, its preparation method and application in epoxy resin system materials

Abstract

The present invention provides a compound accelerator, which comprises a first accelerator and a second accelerator. The first accelerator comprises at least one of a tertiary amine accelerator and an imidazole accelerator. The second accelerator comprises a small molecule alcohol with a molecular weight of 50-200. The present invention solves the problem that the existing accelerators cannot reduce the reaction heat while increasing the reaction rate. At the same time, the present invention also provides a preparation method of the compound accelerator and its application in an epoxy resin system material.

Description

Technical Field

[0001] The present invention relates to the technical field of accelerators, and particularly to a compound accelerator, a preparation method thereof, and an application thereof in an epoxy resin system material. Background Art

[0002] An accelerator is a substance that can increase the reaction rate when used in combination with a catalyst or a fixing agent. Accelerators are widely used in epoxy resin adhesives, polyurethane adhesives, phenolic resin adhesives, unsaturated polyester resin adhesives, fast-curing acrylate structural adhesives, anaerobic adhesives, and rubber and rubber-based adhesives. Different accelerators are selected according to different types of adhesives, so that the adhesive can have a high acceleration efficiency when adding a small amount of accelerator, and the selected accelerator does not affect the process performance and physical and mechanical properties of the adhesive. At the same time, it is required that the accelerator is non-toxic or low-toxic and has no harm to the human body and the environment.

[0003] Epoxy resin generally refers to a high molecular weight prepolymer containing two or more epoxy groups and having an aliphatic, alicyclic or aromatic chain segment as the main chain, and its molecular formula is (C 11 H 12 O3) n , and can be formed by the polycondensation reaction of epichlorohydrin with bisphenol A or polyol. Due to the chemical activity of the epoxy group, epoxy resin can be ring-opened by various curing agents containing active hydrogen or catalysts containing active functional groups, and cured and crosslinked to form a three-dimensional network structure, so that the high molecular weight prepolymer becomes a stable polymer. The cured epoxy resin has excellent physical and mechanical properties and electrical insulation properties. At the same time, the cured epoxy resin has good adhesion performance with various materials, and the curing process of the epoxy resin material is flexible. Epoxy resin can be made into casting molding materials, composite materials, adhesives, coatings, mold materials, pultruded molding materials, filament winding molding materials and injection molding materials. Epoxy resin is widely used in various fields of the national economy.

[0004] The accelerator can accelerate the reaction rate between the epoxy resin and the curing agent, lower the curing reaction temperature and shorten the curing time. For different types of curing agents, the accelerating effects of accelerators with different components are also different. Currently, the commonly used accelerators for epoxy resin and curing agent include quaternary ammonium salt accelerators, tertiary amine accelerators, substituted ureas and imidazole accelerators. After the epoxy resin and the curing agent are mixed to obtain a composition, when using the composition, it is always desired that the composition has a long pot life, which is convenient for both the storage of the composition and the actual operation. However, in some actual uses, such as bonding, solvent-free paint coating, and flow process operation, it is often required that the composition can have a short and reasonable pot life to control the time of the process. When encountering such requirements, various corresponding accelerators need to be added to the composition to accelerate the reaction between the curing agent and the epoxy group.

[0005] To obtain a better promotion effect, more than one promoter is often added to the composition. Each promoter has a different promotion effect on the epoxy resin and the curing agent. Adding different types of promoters will also affect the relevant properties of the composition, such as the curing temperature and the glass transition temperature of the reaction. While improving one aspect of the performance, different promoters may reduce other properties of the composition. When compounding promoters with different promoting effects, there will be different synergistic effects among them, influencing each other, and it is difficult to achieve the desired promotion effect. For example, adding different types of promoters can increase the reaction rate but cannot reduce the heat of reaction formed during the reaction. Excessive heat release during the reaction will cause the temperature in the system to rise, greatly affecting the use of the curing agent and the epoxy resin.

[0006] Therefore, it is necessary to provide a new compound promoter, its preparation method, and its application in the epoxy resin system material to solve the above problems existing in the prior art. Summary of the Invention

[0007] The purpose of the present invention is to provide a compound promoter, its preparation method, and its application in the epoxy resin system material to solve the problem that the promoter in the prior art cannot reduce the heat of reaction while increasing the reaction rate, and at the same time does not affect the glass transition temperature of the thermosetting resin composite, and even increases the glass transition temperature of the thermosetting resin composite.

[0008] To achieve the above purpose, the compound promoter of the present invention includes a first promoter and a second promoter. The first promoter includes at least one of a tertiary amine promoter and an imidazole promoter. The second promoter includes a small molecule alcohol, and the molecular weight of the small molecule alcohol is 50-200.

[0009] The beneficial effect of the compound promoter of the present invention is that: the compound promoter includes a first promoter and a second promoter. Since the lone pair electrons on the nitrogen atom in the first promoter will first attack the weakly charged carbon atom on the epoxy group, thereby forming an intermediate zwitterion. The intermediate zwitterion will continue to attack the next epoxy group through an anionic polymerization mechanism to carry out homopolymerization, generating a large amount of heat of reaction; the presence of the second promoter can provide protons, and the intermediate zwitterion will generate an alcoholate with the protons, and the alcoholate further reacts with the epoxy group to complete the anionic polymerization, thereby reducing the heat of reaction; the molecular weight of the small molecule alcohol is 50-200, which reduces the difficulty of proton extraction, thereby keeping the glass transition temperature of the thermosetting resin composite unchanged or even increasing. The compound promoter of the present invention solves the problem that the promoter in the prior art cannot reduce the heat of reaction while increasing the reaction rate.

[0010] Optionally, the mass ratio of the first accelerator to the second accelerator is (0.5 - 2):1. The beneficial effect is that all alcoholates are formed between the intermediate zwitterions and protons, and there will be no separate intermediate zwitterions.

[0011] Optionally, the small molecule alcohol is a fatty alcohol with a carbon chain of C1 - C5. The beneficial effect is that the protons on the fatty alcohol will not attack the epoxy group too quickly, so that the thermosetting resin composite has sufficient operable time at room temperature.

[0012] Optionally, the small molecule alcohol contains at least one alcoholic hydroxyl group. The beneficial effect is that the protons on the small molecule alcohol will not attack the epoxy group too quickly or too slowly, so that the thermosetting resin composite has an appropriate operable time at room temperature.

[0013] Optionally, the small molecule alcohol includes at least one of n-propanol, isopropanol, 1,2-propanediol, tert-butanol, and 3-methyl-2-butanol.

[0014] Optionally, the tertiary amine accelerator includes at least one of 2,4,6-tris(dimethylaminomethyl)phenol, N,N-dimethylbenzylamine, tetramethylguanidine, 3-dimethylaminopropylamine, and N,N-dimethyl-m-toluidine.

[0015] Optionally, the imidazole accelerator includes at least one of 1-methylimidazole, 2-phenylimidazole, 2-methylimidazole, and 2-phenyl-4-methylimidazole.

[0016] Another object of the present invention provides a preparation method of a compound accelerator, comprising the following steps:

[0017] S0: Provide a first accelerator and a second accelerator, wherein the first accelerator includes at least one of a tertiary amine accelerator and an imidazole accelerator, and the second accelerator includes a small molecule alcohol with a molecular weight of 50 - 200;

[0018] S1: After mixing the first accelerator and the second accelerator according to a mass ratio of (0.5 - 2):1, the compound accelerator is obtained.

[0019] The beneficial effect of the preparation method of the compound accelerator of the present invention is that the preparation method provided by the present invention is simple, and the compound accelerator prepared can accelerate the reaction rate while reducing the reaction heat.

[0020] Another object of the present invention is to provide an application of a compound accelerator in an epoxy resin system material. The compound accelerator is used in the preparation of a curing agent, the curing agent includes a first curing agent and the compound accelerator, the first curing agent includes at least one of an amino-terminated polyetheramine and an acid anhydride curing agent, the compound accelerator includes a first accelerator and a second accelerator, the first accelerator includes at least one of a tertiary amine accelerator and an imidazole accelerator, the second accelerator includes a small molecule alcohol, the molecular weight of the small molecule alcohol is 50-200, and the mass ratio of the first accelerator to the second accelerator is (0.5-2):1.

[0021] The beneficial effect of the application of the compound accelerator of the present invention in the epoxy resin system material is that the compound accelerator enables the curing agent to accelerate the reaction rate while reducing the reaction heat generated by the reaction.

[0022] Optionally, the preparation method of the curing agent includes the steps of: mixing and stirring the first curing agent and the compound accelerator to obtain the curing agent, wherein the mass percentage of the compound accelerator in the curing agent is 2-8%.

[0023] Optionally, the curing agent is used in the preparation of a thermosetting resin composite material, the thermosetting resin composite material includes an epoxy resin and a curing agent, and the mass ratio of the epoxy resin to the curing agent is (2.5-3.3):1. Detailed Description of the Invention

[0024] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention. Unless otherwise defined, the technical terms or scientific terms used herein shall have the ordinary meanings understood by those of ordinary skill in the art in the field to which the present invention belongs. The words such as "including" used herein mean that the elements or objects appearing before this word cover the elements or objects listed after this word and their equivalents, without excluding other elements or objects.

[0025] The embodiment of the present invention provides a compound accelerator, including a first accelerator and a second accelerator. The first accelerator includes at least one of a tertiary amine accelerator and an imidazole accelerator, and the second accelerator includes a small molecule alcohol, and the molecular weight of the small molecule alcohol is 50-200.

[0026] Specifically, the compound accelerator includes a first accelerator and a second accelerator. Since the lone pair electrons on the nitrogen atom in the first accelerator will first attack the weakly charged carbon atom on the epoxy group, an intermediate zwitterion is formed. The intermediate zwitterion will continue to attack the next epoxy group through an anionic polymerization mechanism to undergo homopolymerization, generating a large amount of reaction heat. The presence of the second accelerator can provide protons. The intermediate zwitterion will generate an alkoxide with the protons, and the alkoxide will further react with the epoxy group to complete anionic polymerization, thereby reducing the reaction heat. The molecular weight of the small molecule alcohol is 50-200, which reduces the difficulty of proton extraction, so that the glass transition temperature of the thermosetting resin composite remains unchanged or even increases. The compound accelerator of the present invention solves the problem that the accelerator in the prior art cannot reduce the reaction heat while increasing the reaction rate.

[0027] In some embodiments of the present invention, the reaction mechanisms of the first accelerator and the second accelerator are as follows:

[0028]

[0029] In some embodiments of the present invention, the mass ratio of the first accelerator to the second accelerator is (0.5-2):1. This enables all the intermediate zwitterions and protons to form alkoxides, and there will be no separate intermediate zwitterions. In some specific embodiments, the mass ratio of the first accelerator to the second accelerator is any one of 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1, 1.6:1, 1.7:1, 1.8:1, and 1.9:1.

[0030] In some specific embodiments of the present invention, the molecular weight of the small molecule alcohol is 50-150. In some more specific embodiments, the molecular weight of the small molecule alcohol is 60-100.

[0031] In some embodiments of the present invention, the small molecule alcohol is a fatty alcohol with a carbon chain of C1-C5. If the carbon chain is too long and the molecular weight is too large, proton extraction will be very difficult, the promoting effect will be weak, and at the same time, the glass transition temperature Tg of the thermosetting resin composite will be reduced.

[0032] In some embodiments of the present invention, the small molecule alcohol contains at least one alcoholic hydroxyl group. This enables the protons on the small molecule alcohol to attack the epoxy group neither too fast nor too slow, so that the thermosetting resin composite has an appropriate operable time at room temperature. The phenolic hydroxyl group is too acidic, and the protons on the phenolic hydroxyl group attack the epoxy group too fast, resulting in too short an operable time at room temperature.

[0033] In some embodiments of the present invention, the small molecule alcohol includes at least one of n-propanol, isopropanol, 1,2-propanediol, tert-butanol, and 3-methyl-2-butanol.

[0034] In some embodiments of the present invention, the tertiary amine accelerators include at least one of 2,4,6-tris(dimethylaminomethyl)phenol, N,N-dimethylbenzylamine, tetramethylguanidine, 3-dimethylaminopropylamine, and N,N-dimethyl-m-toluidine. In some specific embodiments, the CAS number of 2,4,6-tris(dimethylaminomethyl)phenol is 90-72-2, abbreviated as K54; the CAS number of N,N-dimethylbenzylamine is 103-83-3, abbreviated as BDMA; the CAS number of tetramethylguanidine is 80-70-6; the CAS number of 3-dimethylaminopropylamine is 109-55-7; the CAS number of N,N-dimethyl-m-toluidine is 121-72-2.

[0035] In some embodiments of the present invention, the imidazole accelerators include at least one of 1-methylimidazole, 2-phenylimidazole, 2-methylimidazole, and 2-phenyl-4-methylimidazole. In some specific embodiments, the CAS number of 1-methylimidazole is 616-47-7, abbreviated as 1MI; the CAS number of 2-phenylimidazole is 670-96-2, abbreviated as 2PI; the CAS number of 2-methylimidazole is 693-98-1, abbreviated as 2MI; the CAS number of 2-phenyl-4-methylimidazole is 827-43-0, abbreviated as 2P4ZM.

[0036] Embodiments of the present invention provide a preparation method of a compound accelerator, including the following steps:

[0037] S0: Provide a first accelerator and a second accelerator, wherein the first accelerator includes at least one of a tertiary amine accelerator and an imidazole accelerator, and the second accelerator includes a small molecule alcohol with a molecular weight of 50-200;

[0038] S1: Mix the first accelerator and the second accelerator according to a mass ratio of (0.5-2):1, and then obtain the compound accelerator. The preparation method provided by the present invention is simple, and the compound accelerator prepared can accelerate the reaction rate while reducing the reaction heat.

[0039] An embodiment of the present invention further provides an application of a compound accelerator in an epoxy resin system material. The compound accelerator is used in the preparation of a curing agent, the curing agent includes a first curing agent and the compound accelerator, the first curing agent includes at least one of an amino-terminated polyetheramine and an acid anhydride curing agent, the compound accelerator includes a first accelerator and a second accelerator, the first accelerator includes at least one of a tertiary amine accelerator and an imidazole accelerator, the second accelerator includes a small molecule alcohol, the molecular weight of the small molecule alcohol is 50 - 200, and the mass ratio of the first accelerator to the second accelerator is (0.5 - 2):1. The compound accelerator enables the curing agent to accelerate the reaction rate while reducing the reaction heat generated by the reaction.

[0040] In some specific embodiments of the present invention, the amino-terminated polyetheramine is selected from polyetheramines with a functionality of 2 and a molecular weight of 200 - 500, and the acid anhydride curing agent is selected from phthalic anhydride, tetrahydrophthalic anhydride, and hexahydrophthalic anhydride.

[0041] In some specific embodiments of the present invention, the first curing agent includes at least one of Zhengda's ZD123 and ZD140, Akoli's MA223 and MA240, Chenghua's CAD230, and Huntsman's D230.

[0042] In some embodiments of the present invention, the preparation method of the curing agent includes the step of mixing and stirring the first curing agent and the compound accelerator to obtain the curing agent, wherein the mass percentage of the compound accelerator in the curing agent is 2 - 8%. In some specific embodiments, the mass percentage of the compound accelerator in the curing agent is any one of 3%, 4%, 5%, 6%, and 7%.

[0043] In some embodiments of the present invention, the curing agent is used in the preparation of a thermosetting resin composite material, the thermosetting resin composite material includes an epoxy resin and a curing agent, and the mass ratio of the epoxy resin to the curing agent is (2.5 - 3.3):1. In some specific embodiments, the mass ratio of the epoxy resin to the curing agent is any one of 2.6:1, 2.7:1, 2.8:1, 2.9:1, 3.0:1, 3.1:1, and 3.2:1.

[0044] In some specific embodiments of the present invention, the epoxy resin includes bisphenol A glycidyl ether type epoxy resin and bisphenol F type epoxy resin. In some more specific embodiments, the epoxy resin includes at least one of Nanya's NPEL127E, Yangnong Jinhu's YN1827, Dongdu's YD127E, Baling Petrochemical's CYD127, and Taiwan Changchun's BE186EL.

[0045] The technical solutions of the embodiments of the present invention are elaborated in detail through specific embodiments below.

[0046] Example

[0047] The first curing agent is D230 from Huntsman; the imidazole accelerator is 1-methylimidazole, abbreviated as 1MI in English; the tertiary amine accelerator is 2,4,6-tris(dimethylaminomethyl)phenol, abbreviated as K54, and / or, the tertiary amine accelerator is N,N-dimethylbenzylamine, abbreviated as BDMA; the macromolecular alcohol is benzyl alcohol, abbreviated as BA; the small molecule alcohol is 1,2-propanediol.

[0048] Weigh 100 grams of D230 as the blank curing agent; weigh 97 grams of D230, 1 gram of 1MI and 2 grams of 1,2-propanediol, then put them into a double-center mixing and dispersing machine (English name: Speed Mixer) for mixing treatment to obtain curing agent 1; weigh 95 grams of D230, 2.5 grams of K54 and 2.5 grams of 1,2-propanediol, then put them into the double-center mixing and dispersing machine for mixing treatment to obtain curing agent 2; weigh 95 grams of D230, 2.5 grams of BDMA and 2.5 grams of 1,2-propanediol, then put them into the double-center mixing and dispersing machine for mixing treatment to obtain curing agent 3; weigh 99 grams of D230 and 1 gram of 1MI, then put them into the double-center mixing and dispersing machine for mixing treatment to obtain comparative curing agent 1; weigh 95 grams of D230 and 5 grams of K54, then put them into the double-center mixing and dispersing machine for mixing treatment to obtain comparative curing agent 2; weigh 95 grams of D230 and 5 grams of BDMA, then put them into the double-center mixing and dispersing machine for mixing treatment to obtain comparative curing agent 3; weigh 95 grams of D230, 2.5 grams of BDMA and 2.5 grams of BA, then put them into the double-center mixing and dispersing machine for mixing treatment to obtain comparative curing agent 4; weigh 97 grams of D230 and 3 grams of BA, then put them into the double-center mixing and dispersing machine for mixing treatment to obtain comparative curing agent 5; weigh 97 grams of D230 and 3 grams of 1,2-propanediol, then put them into the double-center mixing and dispersing machine for mixing treatment to obtain comparative curing agent 6. Calculate the active hydrogen equivalent of the amine of the blank curing agent, curing agents 1-3 and comparative curing agents 1-6. The specific calculation results are shown in Table 1.

[0049] Table 1

[0050] Curing agent D230 1MI K54 BDMA BA 1,2 - propanediol AHEW Blank curing agent 100 / / / / / 60 Curing agent 1 97 1 / / / 2 61.9 Curing agent 2 95 / 2.5 / / 2.5 63.2 Curing agent 3 95 / / 2.5 2.5 63.2 Control curing agent 1 99 1 / / / / 60.6 Control curing agent 2 95 / 5 / / / 63.2 Control curing agent 3 95 / / 5 / / 63.2 Control curing agent 4 95 / / 2.5 2.5 / 63.2 Control curing agent 5 97 / / / 3 / 61.9 Control curing agent 6 97 / / / / 3 61.9

[0051] Note: The active hydrogen equivalent of the curing agent (Amine Hydrogen Equivalent Weight, abbreviated as AHEW) = the molecular weight M of the curing agent w / the number of active hydrogens in the curing agent molecule.

[0052] The blank curing agent, curing agents 1-3, and comparative curing agents 1-6 were respectively mixed with the epoxy resin NPEL127E from South Asia in a double-center mixing and dispersing machine at a rotation speed of 2000 rpm / min for 2 min to obtain thermosetting resin composites, denoted as blank samples, samples 1-3, and comparative samples 1-6. Weighed a part of the blank samples, part of samples 1-3, and part of comparative samples 1-6, then placed them in an aluminum crucible for DSC testing, and finally conducted the measurement of reaction heat and glass transition temperature. The glass transition temperature test was based on the measurement method using DSC (TADSC Q2000) in GB / T19466-2004; the measurement of reaction heat was based on ISO11357-5 standard. The measurement results are shown in Table 2.

[0053] The amount of resin used was calculated by the active hydrogen equivalent. The amount of curing agent required for 100 g of epoxy resin (g) = active hydrogen equivalent of the curing agent × 100 ÷ epoxy equivalent of the epoxy resin.

[0054] The mass ratio of resin to the blank curing agent in the blank sample was 100:33; the mass ratio of resin to curing agent 1 in sample 1 was 100:34; the mass ratio of resin to curing agent 2 in sample 2 was 100:35; the mass ratio of resin to curing agent 3 in sample 3 was 100:35; the mass ratio of resin to comparative curing agent 1 in comparative sample 1 was 100:33; the mass ratio of resin to comparative curing agent 2 in comparative sample 2 was 100:35; the mass ratio of resin to comparative curing agent 3 in comparative sample 3 was 100:35; the mass ratio of resin to comparative curing agent 4 in comparative sample 4 was 100:35; the mass ratio of resin to comparative curing agent 5 in comparative sample 5 was 100:34; the mass ratio of resin to comparative curing agent 6 in comparative sample 6 was 100:34. The resin was the epoxy resin NPEL127E from South Asia with an epoxy equivalent of 180 g / eq.

[0055] Table 2

[0056] Onset Reaction start temperature / °C Peak Peak temperature / °C Heat of reaction / J / g Tg / °C Blank sample 77 109 444 92 Sample 1 72 111 447 86 Sample 2 72 105 427 86 Sample 3 72 106 437 88 Control sample 1 77 114 454 86 Control sample 2 79 109 451 86 Control sample 3 77 111 453 84 Control sample 4 76 109 455 86 Control sample 5 76 110 434 92 Control sample 6 70 105 423 92

[0057] Note: The higher the onset reaction starting temperature, the slower the reaction rate; the lower the onset reaction starting temperature, the faster the reaction rate.

[0058] It can be seen from Table 2 that when comparing sample 1 with comparative sample 1, when the glass transition temperature Tg remains unchanged, the room temperature reaction rate can be increased, the reaction heat can be reduced, thereby reducing the reaction heat release. Sample 1 includes 1,2-propanediol and 1MI, and comparative sample 1 includes 1MI. Compared with imidazole-based accelerators, the compound accelerator can keep the glass transition temperature of the thermosetting resin composite unchanged, while increasing the reaction rate of epoxy resin and curing agent at room temperature and reducing the reaction heat, thereby reducing the reaction heat release.

[0059] As can be seen from Table 2, compared with Comparative Sample 2, when the glass transition temperature Tg of Sample 2 remains unchanged, the reaction rate at room temperature can be increased, and the reaction heat can be greatly reduced, thus reducing the heat release during the reaction. Sample 2 includes 1,2-propanediol and K54, and Comparative Sample 2 includes K54. Compared with the tertiary amine accelerator K54, the compound accelerator can keep the glass transition temperature of the thermosetting resin composite unchanged, while increasing the reaction rate between the epoxy resin and the curing agent at room temperature and greatly reducing the reaction heat, thus reducing the heat release during the reaction.

[0060] As can be seen from Table 2, compared with Comparative Sample 3, Sample 3 can increase the glass transition temperature by 4 °C while increasing the reaction rate at room temperature and reducing the reaction heat, thus reducing the heat release during the reaction. Sample 3 includes 1,2-propanediol and BDMA, and Comparative Sample 3 includes BDMA. Compared with the tertiary amine accelerator BDMA, the compound accelerator can increase the glass transition temperature of the thermosetting resin composite, while greatly reducing the reaction heat between the epoxy resin and the curing agent, thus reducing the heat release during the reaction and increasing the reaction rate between the epoxy resin and the curing agent at room temperature.

[0061] As can be seen from Table 2, compared with Comparative Sample 4, when the glass transition temperature is increased by 2 °C in Sample 3, the reaction heat can be reduced and the reaction rate at normal temperature can be increased. Sample 3 includes 1,2-propanediol and BDMA, and Comparative Sample 4 includes BA and BDMA. Compared with the compound of BA and BDMA, the compound accelerator can increase the glass transition temperature of the thermosetting resin composite, reduce the reaction heat between the epoxy resin and the curing agent, and increase the reaction rate between the epoxy resin and the curing agent at normal temperature.

[0062] Adding 1% of 1MI to the curing agent will reduce the glass transition temperature of the thermosetting resin composite by 6 °C, and there is basically no promoting effect on the reaction between the epoxy resin and the first curing agent D230; while adding 1% of 1MI and 2% of 1,2-propanediol to the curing agent at the same time will keep the glass transition temperature of the thermosetting resin composite unchanged, while reducing the reaction starting temperature, thus increasing the reaction rate between the epoxy resin and the curing agent at room temperature.

[0063] Adding 5% of K54 to the curing agent will increase the heat of reaction between the epoxy resin and the curing agent. However, basically, the reaction between the epoxy resin and the curing agent will not be accelerated, but rather will be reduced. At the same time, the glass transition temperature of the thermosetting resin composite decreases by 6°C. From the data in Table 2, it can be seen that 1% of DMP30 or K54 will cause the glass transition temperature of the thermosetting resin composite to decrease by 1.2°C. When 1% of K54 and 2.5% of 2,4-propanediol are added to the curing agent simultaneously, the starting temperature of the reaction between the epoxy resin and the curing agent decreases, the reaction between the two at room temperature is faster, the heat of reaction decreases, and the glass transition temperature of the thermosetting resin composite decreases by 6°C, reducing the influence of K54 on the glass transition temperature.

[0064] Adding 5% of BDMA to the curing agent causes the glass transition temperature of the thermosetting resin composite to drop by 8°C, and the heat of reaction increases, but the curing temperature remains basically unchanged. When 5% of BDMA and 2.5% of 1,2-propanediol are added to the curing agent simultaneously, the heat of reaction between the epoxy resin and the curing agent decreases, the starting temperature of the reaction decreases, the reaction rate at room temperature is faster, and at the same time, the glass transition temperature of the thermosetting resin composite is 4°C higher than that when BDMA is added alone.

[0065] In D230, neither benzyl alcohol nor 1,2-propanediol has an obvious effect on the thermosetting resin composite, that is, whether benzyl alcohol or 1,2-propanediol is added to D230 will not affect the glass transition temperature of the thermosetting resin composite. Compared with adding benzyl alcohol to D230, adding 1,2-propanediol to D230 accelerates the reaction between the epoxy resin and the curing agent faster at low temperatures. When benzyl alcohol is added to D230, almost no acceleration of the reaction between the epoxy resin and the curing agent at room temperature can be seen. When 3% of benzyl alcohol is added to D230, the reaction between the epoxy resin and the curing agent speeds up slightly at low temperatures, and the heat of reaction also decreases, but both are not obvious.

[0066] In summary, adding small molecule alcohols to imidazole accelerators and / or tertiary amine accelerators can increase the reaction rate between the epoxy resin and the curing agent at room temperature, and at the same time significantly reduce the heat of reaction between the epoxy resin and the curing agent, thereby reducing the heat release of the reaction, but does not affect the glass transition temperature of the thermosetting resin composite, and even increases the glass transition temperature of the thermosetting resin composite.

[0067] Although the embodiments of the present invention have been described in detail above, it is obvious to those skilled in the art that various modifications and changes can be made to these embodiments. However, it should be understood that such modifications and changes all fall within the scope and spirit of the present invention described in the claims. Moreover, the present invention described herein can have other embodiments and can be implemented or realized in various ways.

Claims

1. A compound accelerator, characterized in that, It consists of a first accelerator and a second accelerator. The first accelerator is at least one of a tertiary amine accelerator and an imidazole accelerator, and the second accelerator is a small molecule alcohol. The tertiary amine accelerator is selected from at least one of 2,4,6-tris(dimethylaminomethyl)phenol, N,N-dimethylbenzylamine, tetramethylguanidine, 3-dimethylaminopropylamine, and N,N-dimethyl-m-toluidine. The imidazole accelerator includes at least one of 1-methylimidazole, 2-phenylimidazole, 2-methylimidazole, and 2-phenyl-4-methylimidazole. The small molecule alcohol is selected from 1,2-propanediol. The mass ratio of the first accelerator to the second accelerator is (0.5 - 2):

1.

2. A preparation method of the compound accelerator as described in claim 1, characterized in that, It includes the following steps: S0: Provide a first accelerator and a second accelerator, where the first accelerator is at least one of a tertiary amine accelerator and an imidazole accelerator, and the second accelerator is a small molecule alcohol. The tertiary amine accelerator is selected from at least one of 2,4,6-tris(dimethylaminomethyl)phenol, N,N-dimethylbenzylamine, tetramethylguanidine, 3-dimethylaminopropylamine, and N,N-dimethyl-m-toluidine. The imidazole accelerator includes at least one of 1-methylimidazole, 2-phenylimidazole, 2-methylimidazole, and 2-phenyl-4-methylimidazole. The small molecule alcohol is selected from 1,2-propanediol. S1: After mixing the first accelerator and the second accelerator according to a mass ratio of (0.5 - 2):1, the compound accelerator is obtained.

3. The application of the compound accelerator as described in claim 1 in the epoxy resin system material, characterized in that, It is applied to the preparation of a curing agent. The curing agent includes a first curing agent and the compound accelerator. The first curing agent includes at least one of an amino-terminated polyether and an acid anhydride curing agent. The compound accelerator consists of a first accelerator and a second accelerator. The first accelerator is at least one of a tertiary amine accelerator and an imidazole accelerator, and the second accelerator is a small molecule alcohol. The tertiary amine accelerator is selected from at least one of 2,4,6-tris(dimethylaminomethyl)phenol, N,N-dimethylbenzylamine, tetramethylguanidine, 3-dimethylaminopropylamine, and N,N-dimethyl-m-toluidine. The imidazole accelerator includes at least one of 1-methylimidazole, 2-phenylimidazole, 2-methylimidazole, and 2-phenyl-4-methylimidazole. The small molecule alcohol is selected from 1,2-propanediol. The mass ratio of the first accelerator to the second accelerator is (0.5 - 2):

1.

4. The application of the compound accelerator according to claim 3 in the epoxy resin system material, characterized in that, The preparation method of the curing agent includes the step: After mixing and stirring the first curing agent and the compound accelerator, the curing agent is obtained, where the mass percentage of the compound accelerator in the curing agent is 2 - 8%.

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