Epoxy resin adhesive and preparation method thereof, and composite film

Abstract

The application provides an epoxy resin adhesive and a preparation method and a composite film thereof, wherein the epoxy resin adhesive comprises 5-20 parts by mass of aromatic epoxy resin, 30-60 parts by mass of aliphatic epoxy compound, 12-30 parts by mass of acid anhydride curing agent and 2-8 parts by mass of catalyst modified by the aliphatic epoxy compound. The epoxy resin adhesive provided by the application can improve the flexibility of the epoxy resin while effectively balancing the long low-temperature pot life and high-temperature rapid curing performance by adding a high content of aliphatic epoxy compound into the epoxy resin adhesive and combining the acid anhydride curing agent and the catalyst modified by the aliphatic epoxy compound.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of epoxy resin, in particular to an epoxy resin glue, a preparation method thereof and a composite film. BACKGROUND

[0002] Due to excellent adhesion, electrical insulation and chemical corrosion resistance, epoxy resin is widely used in various devices.

[0003] Epoxy resin has the disadvantage of high brittleness. In view of the above situation, the existing technology generally improves through epoxy modification, curing agent adjustment, addition of reactive diluents, addition of non-reactive toughening resins / compounds and the like. However, the above-mentioned methods not only have limited toughening effect, but also cannot balance the long low-temperature pot life and high-temperature rapid curing characteristics. SUMMARY

[0004] The technical problem to be solved by the present application is to provide an epoxy resin glue, a preparation method thereof and a composite film, so as to solve the technical problem that the existing epoxy resin cannot balance the long low-temperature pot life and high-temperature rapid curing performance under the premise of efficient toughening.

[0005] In order to solve the above problems, the present application is realized through the following technical scheme:

[0006] The present application provides an epoxy resin glue, wherein, in terms of mass fraction, 5-20 parts of aromatic-containing epoxy resin, 30-60 parts of aliphatic epoxy compound, 12-30 parts of acid anhydride curing agent and 2-8 parts of catalyst are included, and the catalyst is modified from the aliphatic epoxy compound.

[0007] Further, in the epoxy resin glue, the aromatic-containing epoxy resin includes one or more of bisphenol A type, bisphenol F type, phenolic type, phenol type and biphenyl type.

[0008] Further, in the epoxy resin glue, the aliphatic epoxy compound includes one or more of C8-C22 glycidyl ether, C8-C22 glycidyl ester and C6-C18 olefin-modified epoxy compound with functionality ≥3.

[0009] Further, in the epoxy resin glue, the catalyst is modified from the aliphatic epoxy compound by a modifier, and the modifier includes one or more of imidazole, alkane imidazole, phenyl imidazole, alkyl imidazoline and phenyl imidazoline.

[0010] Further, in the epoxy resin glue, the acid anhydride curing agent includes one or more of tung oil anhydride, dodecenyl anhydride, liquefied tetrahydrophthalic anhydride, liquefied methyl tetrahydrophthalic anhydride and methyl hexahydrophthalic anhydride.

[0011] Further, the epoxy resin glue, by mass fraction, further comprises 1-4 parts of a thixotropic agent, 0.2-0.5 parts of an antioxidant, and 0.2-0.5 parts of a leveling agent.

[0012] Further, the epoxy resin glue, the thixotropic agent comprises one or more of fumed silica, precipitated silica, organic bentonite, kaolin, attapulgite, or hydrogenated castor oil; and / or

[0013] The antioxidant is selected from one or more of antioxidant 1010, antioxidant 168, antioxidant 1035, antioxidant 245, and triphenyl phosphite; and / or

[0014] The leveling agent is a non-silicon surfactant.

[0015] Further, the epoxy resin glue, the mass ratio of the aliphatic epoxy compound to the aromatic epoxy compound in the epoxy resin glue is 2.4:1-10:1.

[0016] The application also proposes a preparation method of the epoxy resin glue as described above, wherein the preparation method comprises:

[0017] According to the proportion of each component, the aromatic epoxy resin and the aliphatic epoxy compound are mixed to obtain component A;

[0018] According to the proportion of each component, the anhydride curing agent and the catalyst are mixed to obtain component B;

[0019] Components A and B are mixed to obtain the epoxy resin glue.

[0020] Further, in the preparation method, the preparation process of the catalyst comprises:

[0021] In a protective gas atmosphere, a modifier and a catalytic aid are added to the aliphatic epoxy compound, and the mixture is reacted at 80-120°C for 1-3h to obtain the catalyst;

[0022] The modifier comprises one or more of imidazole, alkane imidazole, phenyl imidazole, alkyl imidazoline, and phenyl imidazoline, and the catalytic aid comprises a tertiary amine compound.

[0023] Further, in the preparation method, the tertiary amine compound comprises one or more of N,N-dimethylcyclohexylamine, N,N'-dimethylpyridine, bis(2-dimethylaminoethyl) ether, N,N,N',N'-tetramethylalkylene diamine, triethylamine, and N,N-dimethylbenzylamine.

[0024] Further, in the preparation method, the adding amount of the modifier is 15-30% of the mass of the aliphatic epoxy compound, and the adding amount of the catalytic aid is 10-20% of the mass of the modifier.

[0025] Compared with the prior art, the embodiments of the application have the following advantages:

[0026] In the embodiments of the application, the epoxy resin adhesive provided includes 5-20 parts by mass of aromatic epoxy resin, 30-60 parts by mass of aliphatic epoxy compound, 12-30 parts by mass of acid anhydride curing agent, and 2-8 parts by mass of catalyst, wherein the catalyst is modified from the aliphatic epoxy compound. The high content of aliphatic epoxy compound can significantly improve the flexibility of the epoxy resin material; the acid anhydride curing agent can be well compatible with the system and has low activity at room temperature, so that the long pot life at room temperature can be achieved; and the catalyst is modified from the aliphatic epoxy compound as the base agent, so that the spatial structure of the catalyst is consistent with that of the aliphatic epoxy compound, the catalyst can more fully and efficiently contact and polarize the epoxy groups of the aliphatic epoxy compound in the curing process, the ring-opening activity of the epoxy functional groups is improved, and high-temperature rapid curing is realized.

[0027] It should be understood that the foregoing general description and the following detailed description are only exemplary and explanatory, and cannot limit the application. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a preparation method flow chart of the epoxy resin adhesive provided by the embodiments of the application. DETAILED DESCRIPTION

[0029] In order to make the above-mentioned purposes, features and advantages of the application more obvious and easy to understand, the application will be further described in detail below with reference to the drawings and specific embodiments.

[0030] The epoxy resin adhesive provided by the embodiments of the application includes 5-20 parts by mass of aromatic epoxy resin, 30-60 parts by mass of aliphatic epoxy compound, 12-30 parts by mass of acid anhydride curing agent, 2-8 parts by mass of catalyst, 1-4 parts by mass of thixotropic agent, 0.2-0.5 parts by mass of antioxidant, and 0.2-0.5 parts by mass of leveling agent, wherein the catalyst is modified from the aliphatic epoxy compound.

[0031] The aliphatic epoxy compound is a flexible diluent, and a high content of the aliphatic epoxy compound can significantly improve the flexibility of the epoxy resin material, but can cause the problem of difficult curing. In view of the above problem, the anhydride curing agent and the catalyst are simultaneously added to the glue solution, wherein the anhydride curing agent can be well compatible with the system, and has low activity at room temperature, so that the long pot life at room temperature can be achieved; and the catalyst is modified by using the aliphatic epoxy compound as a base agent, and has the same spatial structure as the aliphatic epoxy compound, so that the catalyst can more fully and efficiently contact and polarize the epoxy groups of the aliphatic epoxy compound during the curing process of the anhydride curing agent under high temperature exceeding 100 DEG C, and the ring-opening activity of the epoxy functional group is improved, so that rapid curing is realized.

[0032] In the embodiment of the present application, by adding a high content of aliphatic epoxy compound to the epoxy resin glue, and combining the anhydride curing agent and the catalyst modified by the aliphatic epoxy compound, the flexibility of the epoxy resin can be improved, and the long low-temperature pot life and high-temperature rapid curing performance can be effectively considered.

[0033] In actual application, the flexible epoxy resin glue provided by the embodiment of the present application has a product elongation at break of more than 150%; in addition, the flexible epoxy resin glue has a pot life of more than 48 hours at room temperature, and a curing time of less than or equal to 5 minutes at 100-130 DEG C, and has excellent high-temperature rapid curing performance.

[0034] Optionally, in an embodiment, the epoxy resin glue further includes 1-4 parts of a thixotropic agent, 0.2-0.5 parts of an antioxidant, and 0.2-0.5 parts of a leveling agent by mass.

[0035] Optionally, in an embodiment, the thixotropic agent includes one or more of fumed silica, precipitated silica, organic bentonite, kaolin, attapulgite or hydrogenated castor oil.

[0036] Optionally, in an embodiment, the antioxidant is selected from one or more of antioxidant 1010, antioxidant 168, antioxidant 1035, antioxidant 245 and triphenyl phosphite.

[0037] Optionally, in an embodiment, the leveling agent is a non-silicon leveling agent, including but not limited to acrylic resin, urea-formaldehyde resin, melamine-formaldehyde resin and other acrylate leveling agents. The non-silicon leveling agent has good compatibility with the resin, is not easy to precipitate on the surface, can more effectively reduce the surface tension of the finishing liquid, and thus form a flat, smooth and uniform coating film.

[0038] Optionally, in one embodiment, the epoxy resin adhesive comprises component A and component B, and the raw materials for preparing component A comprise the following components by mass fraction: 5-20 parts of aromatic epoxy resin, 30-60 parts of aliphatic epoxy compound, 1-4 parts of thixotropic agent, 0.2-0.5 parts of antioxidant, and 0.2-0.5 parts of leveling agent; and the raw materials for preparing component B comprise the following components: 12-30 parts of acid anhydride curing agent, and 2-8 parts of catalyst.

[0039] The glue solution is divided into component A and component B, which facilitates long-term storage. When the glue solution is used, the components A and B are stirred and mixed for 10-15 min, and then vacuum degassing is performed, to obtain the epoxy resin adhesive.

[0040] Preferably, components A and B are in liquid state at room temperature, and the viscosity is less than 3000 cp, which facilitates production operations such as batching, mixing, and vacuum degassing, and can effectively maintain the uniformity and stability of the glue solution, so that the product has fewer defects.

[0041] Optionally, in the epoxy resin adhesive provided in the embodiments, the mass ratio of the aliphatic epoxy compound to the aromatic epoxy compound is 2.4:1-10:1, which can more significantly improve the flexibility of the epoxy resin adhesive. In some embodiments, the mass ratio of the aliphatic epoxy compound to the aromatic epoxy compound can be one of 2.4:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1 or a range value of any two thereof.

[0042] Optionally, in one specific embodiment, the mass ratio of the aliphatic epoxy compound to the aromatic epoxy compound is 2.4:1-10:1, and the amount of the acid anhydride curing agent is calculated based on the long-chain epoxy compound and the benzene ring epoxy compound. Specifically, the sum M1 of the total epoxy molar amounts of the aliphatic epoxy compound and the aromatic epoxy compound is calculated first, then the acid anhydride molar number M2 in the acid anhydride curing agent is 0.7-1.3 times of M1, and finally the amount of the acid anhydride curing agent is obtained by multiplying the acid anhydride molecular weight by M2. The amount of the catalyst is 5%-10% of the total mass of the long-chain epoxy compound and the benzene ring epoxy compound.

[0043] More preferably, the amount of the aliphatic epoxy compound is 3-8 times of the amount of the aromatic epoxy compound.

[0044] More preferably, M2 is 0.8-1.2 times of M1, and more preferably, M2 is 0.9-1.1 times of M1.

[0045] More preferably, the amount of the catalyst is 5%-9% of the total mass of the aliphatic epoxy compound and the aromatic epoxy compound.

[0046] In the embodiments of the present application, the aromatic epoxy resin is the main part of the resin structure, which is an epoxy resin containing benzene ring structure. The benzene ring structure makes it more suitable to be combined with aliphatic epoxy compounds to form a high-flexibility resin adhesive. Optionally, the aromatic epoxy resin includes one or more of bisphenol A type, bisphenol F type, phenolic type, phenol type, and biphenyl type.

[0047] In the embodiments of the present application, the aliphatic epoxy compound is a flexible epoxy compound with C6-C22. Optionally, the aliphatic epoxy compound includes one or more of C8-C22 glycidyl ether, C8-C22 glycidyl ester, and C6-C18 long-chain alkene modified epoxy compound with a functionality of ≥3.

[0048] Optionally, in one embodiment, the catalyst is modified by a modifier using the aliphatic epoxy compound as a base. The modifier includes one or more of imidazole, alkane imidazole, phenyl imidazole, alkyl imidazoline, and phenyl imidazoline. The catalyst can be more easily contacted with the epoxy group of the aliphatic epoxy compound and polarized, thereby improving the ring-opening activity of the epoxy functional group and achieving cross-linking and curing effects.

[0049] In the embodiments of the present application, the anhydride curing agent should be a liquid curing agent at room temperature to facilitate dissolution to form a glue solution.

[0050] Optionally, in one embodiment, the anhydride curing agent includes one or more of tung oil anhydride, dodecenyl anhydride, liquefied tetrahydrophthalic anhydride, liquefied methyl tetrahydrophthalic anhydride, and methyl hexahydrophthalic anhydride. The anhydride curing agent is in a liquid state at room temperature, has good compatibility with the system, and has low activity at room temperature. It not only achieves the effect of long pot life at room temperature, but also facilitates dissolution to form a glue solution.

[0051] Optionally, in another embodiment, the anhydride curing agent is a combined anhydride that can be liquefied at room temperature after compounding.

[0052] The embodiments of the present application also provide a preparation method of the epoxy resin adhesive as described above, which includes steps 101-103.

[0053] Step 101, mixing the aromatic epoxy resin and the aliphatic epoxy compound according to the ratio of each component to obtain component A;

[0054] Step 102, mixing the anhydride curing agent and the catalyst according to the ratio of each component to obtain component B;

[0055] Step 103, mixing component A and component B according to the ratio of each component to obtain the epoxy resin adhesive.

[0056] In the embodiment of the present application, the aromatic epoxy resin and the aliphatic epoxy compound are mixed according to the proportion of each component to obtain component A in the glue solution, the acid anhydride curing agent and the catalyst are mixed to obtain component B in the glue solution, which is convenient for long-time storage. When the glue solution is used, component A and component B are stirred and mixed for 10-15 min according to the proportion of each material, and then vacuum degassing is performed, to obtain the above-mentioned epoxy resin glue.

[0057] In the embodiment of the present application, component A and component B are both liquid at room temperature, and the viscosity is less than 3000 cp, which is convenient for production operations such as batching, mixing and vacuum degassing, can effectively maintain the uniformity and stability of the glue solution, and makes the product defects less.

[0058] In the embodiment of the present application, the catalyst is modified from the aliphatic epoxy compound, that is, the catalyst is obtained by modifying the aliphatic epoxy compound.

[0059] Optionally, in one embodiment, the step 101 further includes:

[0060] According to the proportion of each component, the thixotropic agent, the antioxidant and the leveling agent are added to component A.

[0061] Optionally, in one embodiment, the preparation process of the catalyst includes:

[0062] In a protective gas atmosphere, a modifier and a catalytic aid are added to the aliphatic epoxy compound, and the reaction is carried out at 80-120℃ for 1-3h to obtain the catalyst;

[0063] In the embodiment of the present application, the modifier includes one or more of imidazole, alkane imidazole, phenyl imidazole, alkyl imidazoline and phenyl imidazoline, and the catalytic aid includes a tertiary amine compound.

[0064] In the embodiment of the present application, the aliphatic epoxy compound is modified by the catalyst such as imidazole, alkane imidazole, phenyl imidazole, alkyl imidazoline and phenyl imidazoline, and a tertiary amine compound is added to the network catalytic aid reaction, which can effectively improve the reaction activity of the prepared catalyst. In the embodiment of the present application, the protective gas is nitrogen, argon or other gas that does not participate in the reaction.

[0065] In the embodiment of the present application, the modification reaction temperature is controlled to be 80-120℃ and the time is controlled to be 1-3h, because the aliphatic epoxy compound cannot be effectively modified at too low temperature and for too short time, and side reactions are easy to occur at too high temperature and for too long time.

[0066] Optionally, in some embodiments, the reaction temperature can be one of 80℃, 85℃, 90℃, 95℃, 100℃, 105℃, 110℃, 115℃, 120℃ or a range value of any two of them, and the reaction time can be one of 1h, 1.5h, 2h, 2.5h, 3h or a range value of any two of them.

[0067] Optionally, in one specific embodiment, the tertiary amine compound includes one or more of N,N-dimethylcyclohexylamine, N,N'-dimethylpyridine, bis(2-dimethylaminoethyl)ether, N,N,N',N'-tetramethylalkylenediamine, triethylamine, N,N-dimethylbenzylamine.

[0068] Optionally, in one specific embodiment, the amount of the modifier added is 15-30% of the mass of the aliphatic epoxy compound, and the amount of the catalytic aid added is 10-20% of the mass of the modifier, i.e. in the preparation of the above-mentioned catalyst, the mass ratio of the aliphatic epoxy compound, the modifier, and the catalytic aid is 100:(15-30):(10-20), which can sufficiently modify the aliphatic epoxy compound and improve its catalytic reaction activity.

[0069] The present application is described in detail below through examples.

[0070] Performance test method:

[0071] (1) Viscosity test: tested according to the national standard GB / T 22314-2008;

[0072] (2) Pot life test: the A and B component samples were placed in a constant temperature room at 25℃ for 24h, and then the total glue solution was prepared with a total amount of 150g and mixed for testing the viscosity, and when the viscosity increase value was 2 times the initial viscosity value, it was the pot life;

[0073] (3) Curing time test: the national standard GB / T 12007.7-1989 was used, and the test temperature was 120℃;

[0074] (4) Elongation at break test: tested according to the national standard GB / T 2567-2008.

[0075] Example 1

[0076] (1) Preparation of A component:

[0077] Mix 15 parts of bisphenol A type epoxy resin NPEL-128 and 50 parts of aliphatic epoxy compound castor oil triglycidyl ether, then vacuum stir at 100°C for 60 min to remove water, then add 2.2 parts of thixotropic agent fumed silica, 0.4 parts of antioxidant 168 and 0.4 parts of non-silicon leveling agent BYK-3900P, continue to stir and mix for 45 min to obtain component A.

[0078] (2) Preparation of catalyst:

[0079] Pour 6 parts of the above aliphatic epoxy compound into the reaction kettle, vacuum to remove air in the kettle, then introduce nitrogen protection, then add 1.2 parts of modifier imidazole and 0.18 parts of catalytic aid N,N-dimethylbenzylamine, react at 100°C under nitrogen atmosphere for 2h, then cool for standby.

[0080] (3) Preparation of component B:

[0081] Pour 15 parts of anhydride curing agent liquid methyltetrahydrophthalic anhydride and 5 parts of the above catalyst into the mixing kettle, stir and mix for 1.5h.

[0082] (4) Preparation of glue solution before use:

[0083] Pour the above-mentioned component A and component B materials into the stirring kettle according to the mass ratio of 68:20, stir and mix for 12 min, then perform vacuum degassing treatment to obtain the product glue.

[0084] Example 2

[0085] The difference between Example 2 and Example 1 is that in step (1), the bisphenol A type epoxy resin NPEL-128 is adjusted to bisphenol F type epoxy resin NPEF-170.

[0086] Example 3

[0087] The difference between Example 3 and Example 1 is that in step (1), the aliphatic epoxy compound castor oil triglycidyl ether is adjusted to dodecene glycidyl ether.

[0088] Example 4

[0089] The difference between Example 4 and Example 1 is that in step (1), the amount of bisphenol A type epoxy resin NPEL-128 is adjusted to 5 parts by mass, and in step (4), the component A and component B materials are poured into the stirring kettle according to the mass ratio of 58:20.

[0090] Example 5

[0091] Example 5 differs from Example 1 in that in step (1), the amount of bisphenol A type epoxy resin NPEL-128 is adjusted to 20 parts by mass, and in step (4), the A, B component materials are put into the stirred kettle in a mass ratio of 73:20.

[0092] Example 6

[0093] Example 6 differs from Example 1 in that in step (1), the amount of aliphatic epoxy compound is adjusted to 36 parts by mass, and in step (4), the A, B component materials are put into the stirred kettle in a mass ratio of 54:20.

[0094] Example 7

[0095] Example 7 differs from Example 1 in that in step (1), the amount of aliphatic epoxy compound is adjusted to 30 parts by mass, and in step (4), the A, B component materials are put into the stirred kettle in a mass ratio of 48:20.

[0096] Example 8

[0097] Example 8 differs from Example 1 in that in step (1), the amount of aliphatic epoxy compound is adjusted to 60 parts by mass, and in step (4), the A, B component materials are put into the stirred kettle in a mass ratio of 78:20.

[0098] Example 9

[0099] Example 9 differs from Example 1 in that in step (3), the amount of acid anhydride curing agent is adjusted to 12 parts by mass, and in step (4), the A, B component materials are put into the stirred kettle in a mass ratio of 68:17.

[0100] Example 10

[0101] Example 10 differs from Example 1 in that in step (3), the amount of acid anhydride curing agent is adjusted to 25 parts by mass; and in step (4), the A, B component materials are put into the stirred kettle in a mass ratio of 68:30.

[0102] Example 11

[0103] Example 11 differs from Example 1 in that in step (3), the amount of acid anhydride curing agent is adjusted to 30 parts by mass; and in step (4), the A, B component materials are put into the stirred kettle in a mass ratio of 68:35.

[0104] Example 12

[0105] Example 12 differs from Example 1 in that in step (3), the amount of catalyst added is adjusted to 2 parts by mass; and in step (4), the A, B component materials are fed into the stirred kettle in a mass ratio of 68:17.

[0106] Example 13

[0107] Example 13 differs from Example 1 in that in step (3), the amount of catalyst added is adjusted to 8 parts by mass; and in step (4), the A, B component materials are fed into the stirred kettle in a mass ratio of 68:23.

[0108] Example 14

[0109] Example 14 differs from Example 1 in that in step (2), the imidazole is adjusted to an alkyl imidazoline.

[0110] Example 15

[0111] Example 15 differs from Example 1 in that in step (2), the acid anhydride curing agent is adjusted to dodecenyl anhydride.

[0112] Comparative Example 1

[0113] Comparative Example 1 differs from Example 1 in that in step (1), the amount of aliphatic epoxy compound added is adjusted to 20 parts by mass, and in step (4), the A, B component materials are fed into the stirred kettle in a mass ratio of 38:20.

[0114] Comparative Example 2

[0115] Comparative Example 2 differs from Example 1 in that in step (1), the amount of aromatic epoxy compound bisphenol A type epoxy resin NPEL-128 added is adjusted to 30 parts by mass, and in step (4), the A, B component materials are fed into the stirred kettle in a mass ratio of 83:20.

[0116] Comparative Example 3

[0117] Comparative Example 3 differs from Example 1 in that in step (3), the amount of acid anhydride curing agent liquid methyl tetrahydrophthalic anhydride added is adjusted to 10 parts by mass, and in step (4), the A, B component materials are fed into the stirred kettle in a mass ratio of 68:15.

[0118] Comparative Example 4

[0119] Comparative Example 4 differs from Example 1 in that in step (3), the amount of catalyst added is adjusted to 10 parts by mass, and in step (4), the A, B component materials are fed into the stirred kettle in a mass ratio of 68:25.

[0120] Comparative Example 5

[0121] The difference between Comparative Example 5 and Example 1 is that the aliphatic epoxy compound castor oil triglycidyl ether is adjusted to 1,6-hexanediol diglycidyl ether.

[0122] Comparative Example 6

[0123] The difference between Comparative Example 6 and Example 1 is that step (2) is omitted, and in step (3), the catalyst is adjusted to an aliphatic epoxy compound castor oil triglycidyl ether.

[0124] Comparative Example 7

[0125] The difference between Comparative Example 7 and Example 1 is that step (2) is omitted, and in step (3), the anhydride curing agent liquefied methyltetrahydrophthalic anhydride is directly used as component B, and in step (4), the A and B component materials are added into the stirred tank according to a mass ratio of 68:15.

[0126] Comparative Example 8

[0127] The difference between Comparative Example 8 and Example 1 is that the curing agent is adjusted to a modified amine latent curing agent XH-349.

[0128] The components and proportions of the product glue in each embodiment and comparative example are shown in Table 1.

[0129] Table 1

[0130]

[0131]

[0132]

[0133] The product glue obtained in each embodiment and comparative example was subjected to viscosity test, pot life test, curing time test and elongation at break test, and the results are shown in Table 2 below.

[0134] Table 2

[0135]

[0136]

[0137] From Table 1, it can be seen from the comparison of Examples 1 to 15 and Comparative Examples 1 to 4 that when the aromatic epoxy resin, the aliphatic epoxy compound, the anhydride curing agent and the catalyst are combined in a mass ratio of 5 to 20:30 to 60:12 to 30:2 to 8, the epoxy resin adhesive obtained not only has excellent flexibility, but also has a long applicable period at room temperature and rapid curing at high temperature; among them, when the aromatic epoxy resin, the aliphatic epoxy compound, the anhydride curing agent and the catalyst are combined in a mass ratio of 15:50:15:5, the comprehensive performance of the epoxy resin adhesive obtained is particularly good; when the mass ratio between the aromatic epoxy resin, the aliphatic epoxy compound, the anhydride curing agent and the catalyst exceeds the above range, the epoxy resin adhesive obtained cannot meet the performance requirements of high flexibility, long applicable period at room temperature and rapid curing at high temperature.

[0138] From the comparison of Examples 1 to 15 and Comparative Examples 5 to 8 in Table 1, it can be seen that after adding a high content of aliphatic epoxy compounds to aromatic epoxy resins, the epoxy resin adhesive prepared by using a matching catalyst modified from the aliphatic epoxy compounds in combination with an acid anhydride curing agent has good flexibility, a long workable period at room temperature, and rapid curing at high temperature; when using a matching catalyst modified from a short-chain epoxy compound, the epoxy resin adhesive prepared has poor flexibility; and when not using a matching catalyst modified from the aliphatic epoxy compound or an acid anhydride curing agent, the epoxy resin adhesive prepared cannot even be cured and formed.

[0139] In summary, in this embodiment, the epoxy resin glue provided includes, by mass, 5 to 20 parts of aromatic epoxy resin, 30 to 60 parts of aliphatic epoxy compound, 12 to 30 parts of anhydride curing agent, 2 to 8 parts of catalyst, 1 to 4 parts of thixotropic agent, 0.2 to 0.5 parts of antioxidant and 0.2 to 0.5 parts of leveling agent, and the above catalyst is modified from an aliphatic epoxy compound. Among them, a high content of aliphatic epoxy compound can significantly improve the flexibility of the epoxy resin material; the anhydride curing agent is well compatible with the system and has low activity at room temperature, which can achieve a long working life at room temperature; and the catalyst is modified with the above aliphatic epoxy compound as a base agent. It has the same spatial structure as the aliphatic epoxy compound and can more fully and efficiently contact and polarize the epoxy group of the aliphatic epoxy compound during the curing process, thereby improving the ring-opening activity of the epoxy functional group, thereby achieving high-temperature rapid curing.

[0140] Although preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they become aware of the basic inventive concepts. Therefore, the claims are intended to include the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0141] The epoxy resin adhesive and the preparation method thereof are described in detail above, and the principles and implementation manners of the present application are described by using specific examples. The above description of the examples is only used to help understand the method and the core idea of the present application. Meanwhile, for those skilled in the art, according to the idea of the present application, the specific implementation manners and application ranges will be changed, and the above description of the specification should not be understood as a limitation on the present application.

Claims

1. An epoxy resin adhesive, characterized in that: The invention comprises, by mass, 5 to 20 parts of aromatic epoxy resin, 30 to 60 parts of aliphatic epoxy compound, 12 to 30 parts of anhydride curing agent, and 2 to 8 parts of a catalyst. The catalyst is formed by modifying the aliphatic epoxy compound with a modifier. The aliphatic epoxy compound comprises one or more of C8 to C22 glycidyl ether, C8 to C22 glycidyl ester, and C6 to C18 olefin-modified epoxy compound with a functionality ≥ 3. The modifier comprises one or more of imidazole, alkane imidazole, phenyl imidazole, alkyl imidazoline, and phenyl imidazoline.

2. The epoxy resin adhesive according to claim 1, characterized in that The aromatic epoxy resin includes one or more of bisphenol A type, bisphenol F type, novolac type, phenol type, and biphenyl type.

3. The epoxy resin adhesive according to claim 1, characterized in that The acid anhydride curing agent includes one or more of tung oil anhydride, dodecenyl anhydride, liquefied tetrahydrophthalic anhydride, liquefied methyltetrahydrophthalic anhydride, and methylhexahydrophthalic anhydride.

4. The epoxy resin adhesive according to claim 1, characterized in that Calculated by mass, it comprises 6 to 15 parts of aromatic epoxy resin, 35 to 50 parts of aliphatic epoxy compound, 15 to 25 parts of acid anhydride curing agent, and 3 to 7 parts of catalyst.

5. The epoxy resin adhesive according to claim 1, characterized in that Calculated by weight, the composition further includes 1 to 4 parts of a thixotropic agent, 0.2 to 0.5 parts of an antioxidant, and 0.2 to 0.5 parts of a leveling agent.

6. The epoxy resin adhesive according to claim 5, characterized in that The thixotropic agent includes one or more of fumed silica, precipitated silica, organic bentonite, kaolin, attapulgite or hydrogenated castor oil; and / or The antioxidant includes one or more of antioxidant 1010, antioxidant 168, antioxidant 1035, antioxidant 245, and triphenyl phosphite; and / or The leveling agent is a silicon-free leveling agent.

7. The epoxy resin adhesive according to claim 1, characterized in that: The mass ratio of the aliphatic epoxy compound to the aromatic epoxy resin is 2.4:1 to 10:

1.

8. A method for preparing the epoxy resin adhesive according to any one of claims 1 to 7, characterized in that: include: According to the ratio of each component, the aromatic epoxy resin and the aliphatic epoxy compound are mixed to obtain component A; According to the ratio of each component, the anhydride curing agent and the catalyst are mixed to obtain component B; According to the ratio of each component, component A and component B are mixed to obtain epoxy resin glue.

9. The preparation method according to claim 8, characterized in that The preparation process of the catalyst comprises: In a protective gas atmosphere, a modifier and a catalyst promoter are added to an aliphatic epoxy compound, and the mixture is reacted at 80 to 120° C. for 1 to 3 hours to prepare the catalyst; Wherein, the modifier includes one or more of imidazole, alkane imidazole, phenyl imidazole, alkyl imidazoline, and phenyl imidazoline, and the catalyst auxiliary includes a tertiary amine compound.

10. The preparation method according to claim 9, characterized in that The tertiary amine compound includes one or more of N,N-dimethylcyclohexylamine, N,N'-dimethylpyridine, bis(2-dimethylaminoethyl) ether, N,N,N',N'-tetramethylalkylenediamine, triethylamine, and N,N-dimethylbenzylamine.

11. The preparation method according to claim 9, characterized in that The amount of the modifier added is 15-30% of the mass of the aliphatic epoxy compound, and the amount of the catalyst aid added is 10-20% of the mass of the modifier.

12. A composite membrane, characterized in that The invention comprises a multi-layer film, wherein each of the films is bonded together by the epoxy resin adhesive as claimed in any one of claims 1 to 7.

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