Epoxy resin composition and epoxy seam beautifying glue

Abstract

The invention provides an epoxy resin composition and an epoxy sealant, and relates to the technical field of epoxy adhesives. The epoxy resin composition comprises the following components in parts by weight: 100 parts of epoxy resin, 3-10 parts of a first thixotropic agent and 1-10 parts of a second thixotropic agent, the first thixotropic agent is selected from one or a combination of two of fumed silica and organic bentonite; and the second thixotropic agent is double-end epoxy polyether. The epoxy resin composition provided by the invention has better thixotropy and lower vertical sag, and can avoid the phenomenon of glue leakage during operations such as potting and extrusion.

Description

Technical Field

[0001] The invention belongs to the technical field of epoxy adhesives and relates to an epoxy resin composition and an epoxy seam sealant. Background Art

[0002] Epoxy caulking agent is a type of caulking agent, which uses epoxy resin as the main bonding material and is cured with a curing agent. Thixotropic agents are generally added to epoxy caulking agents to facilitate processing and construction. They have good fluidity when subjected to external forces (such as extrusion, filling, etc.), and their fluidity deteriorates when the external forces are removed. Epoxy caulking agents generally use fumed silica and / or bentonite as thixotropic agents, but the thixotropy is insufficient, and the fluidity of the caulking agent is high. It is easy to leak glue during filling and extrusion, and when fillers and color powders are added to the caulking agent, the fillers and color powders are prone to sedimentation.

[0003] Therefore, it is necessary to study the thixotropy of epoxy seam sealant to further improve its thixotropy. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides an epoxy resin composition and an epoxy seam sealant.

[0005] The technical solution of the present invention is as follows:

[0006] An epoxy resin composition, comprising, by weight, 100 parts of epoxy resin, 3-10 parts of a first thixotropic agent and 1-10 parts of a second thixotropic agent;

[0007] The first thixotropic agent is selected from one or a combination of fumed silica and organic bentonite;

[0008] The second thixotropic agent is a double-terminal epoxy polyether.

[0009] Preferably, the fumed silica is hydrophilic fumed silica with a BET specific surface area of ​​not less than 100 m 2 / g.

[0010] Preferably, the weight proportion of the first thixotropic agent is 4-8 parts.

[0011] Preferably, the weight proportion of the second thixotropic agent is 3-8 parts.

[0012] Preferably, the number average molecular weight of the double-terminated epoxy polyether is 200-2000.

[0013] Preferably, the structure of the double-terminated epoxy polyether is as shown in the following formula (1):

[0014] (CH2CHO)CH2O(CH2CH2O) a (CH2CHCH3O)b CH2(CHOCH2)(1)

[0015] Among them, a≥0, b≥0, 3≤a+b≤32.

[0016] An epoxy seam sealant, comprising component A and component B;

[0017] The raw material components of the A component include the epoxy resin composition described in any one of the above technical solutions;

[0018] The B component contains a curing agent.

[0019] Preferably, the weight proportion of the epoxy resin composition in the component A is not less than 50%.

[0020] Preferably, the molecular structure of the curing agent contains no less than 2 amino groups, and the amino groups are selected from primary amino groups and / or secondary amino groups.

[0021] The beneficial effects of the present invention are:

[0022] (1) The present invention adopts a combination of a first thixotropic agent and a second thixotropic agent, which can significantly improve the thixotropy of the epoxy resin composition, and the thixotropy is very good, and the epoxy resin composition has the characteristics of no flow at room temperature, low viscosity, easy filling, and easy extrusion, and no glue leakage occurs during operations such as filling and extrusion. The epoxy resin composition of the present invention is used to prepare epoxy seam glue, and the obtained epoxy seam glue also has good thixotropy, and no glue leakage occurs during operations such as filling and extrusion.

[0023] (2) The second thixotropic agent of the present invention is an active thixotropic agent, which can participate in the curing reaction of epoxy resin, and the main chain structure of polyether can improve the flexibility of epoxy sealant. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a photograph showing the high thixotropy of the epoxy resin composition of Example 1. DETAILED DESCRIPTION

[0025] The technical solution of the present invention is further illustrated and described below through specific implementation methods.

[0026] In order to obtain an epoxy seam adhesive with good thixotropy, on the one hand, the present invention provides an epoxy resin composition, which is composed of 100 parts of epoxy resin, 3-10 parts of a first thixotropic agent and 1-10 parts of a second thixotropic agent in parts by weight;

[0027] The first thixotropic agent is selected from one or a combination of fumed silica and organic bentonite;

[0028] The second thixotropic agent is a double-terminal epoxy polyether.

[0029] In epoxy caulking adhesive, fumed silica and organic bentonite are commonly used thixotropic agents, but there are the following problems: the thixotropic effect is not obvious when the dosage is small, and the thixotropic effect is good when the dosage is large. At the same time, the viscosity of the epoxy caulking adhesive (or epoxy resin composition) will be significantly increased, which is not conducive to operations such as extrusion and filling. The present invention finds that on the basis of the first thixotropic agent, a certain weight of double-terminal epoxy polyether is continuously added as the second thixotropic agent, which can significantly improve the thixotropy of the epoxy resin composition. The epoxy resin composition has poor fluidity or even no flow at room temperature, low viscosity, good thixotropy, can flow well when subjected to external force, and is suitable for operations such as filling and extrusion. Moreover, since the double-terminal epoxy polyether can participate in the curing reaction of the epoxy resin, it is an active thixotropic agent and an active diluent, which does not affect the curing of the epoxy resin, and can also improve the flexibility of the epoxy caulking adhesive.

[0030] The inventors believe that the following reasons may be responsible for the fact that the addition of the second thixotropic agent in the present invention can improve the thixotropy of the epoxy resin composition: the first thixotropic agent uses the surface hydroxyl groups to form three-dimensional hydrogen bonds to form thixotropy. When the hydrogen bonds are destroyed by external force, the viscosity of the caulking adhesive is reduced. When the external force is removed, the hydrogen bonds are restored and the caulking adhesive restores its original viscosity. When the second thixotropic agent is further added in the present invention, there are abundant ether bonds on the second thixotropic agent molecules, so there are at least three hydrogen bond structures in the system, (1) hydrogen bonds formed between the first thixotropic agents, (2) hydrogen bonds formed between the first thixotropic agent and the second thixotropic agent, and (3) hydrogen bonds formed between the second thixotropic agent. Therefore, the epoxy resin composition of the present invention has more hydrogen bonds, richer and more complex structures, and can form a better thixotropic effect.

[0031] In the present invention, the epoxy resin is not particularly limited and can be directly obtained from the market, such as E-44, E-51, 6101, CYD-128, E-12, EP420, EP828, EP966, etc.

[0032] In a preferred embodiment of the present invention, the fumed silica is hydrophilic fumed silica, and the BET specific surface area is not less than 100 m 2 / g. Fumed silica can be purchased directly from the market, such as A200 and A380 from Evonik Degussa, CAB-O-SIL M5 and LM150 from Cabot, and HL-200 from Huifu Company.

[0033] In a preferred embodiment of the present invention, the weight of the first thixotropic agent is 4-8 parts. The weight of the first thixotropic agent is within the above range, and has a better thixotropic effect. The weight of the first thixotropic agent is less or more, and the thixotropic effect is not significant enough. For example, the weight of the first thixotropic agent is 10 parts, and there is no need to add the second thixotropic agent to have good thixotropy, but there is also a problem of high viscosity, and adding the second thixotropic agent will cause the thixotropy to decrease. For example, the weight of the first thixotropic agent can be any value or any value between 4 parts, 4.5 parts, 5 parts, 5.5 parts, 6 parts, 6.5 parts, 7 parts, 7.5 parts, 8 parts, etc., without particular restrictions. More preferably, the weight of the first thixotropic agent is 5-7 parts.

[0034] In a preferred embodiment of the present invention, the weight parts of the second thixotropic agent are 3-8 parts. The weight parts of the second thixotropic agent are in the above range, and have a good thixotropic effect. If the weight of the second thixotropic agent is less, the thixotropic performance cannot be reached. If the weight of the second thixotropic agent is more, the thixotropic performance will be reduced instead, causing the fluidity of the epoxy resin composition to improve. For example, the weight parts of the second thixotropic agent can be 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, 5.5 parts, 6 parts, 6.5 parts, 7 parts, 7.5 parts, 8 parts, etc., any value or any value between them, without particular restrictions. More preferably, the weight parts of the second thixotropic agent are 4-7 parts.

[0035] In a preferred embodiment of the present invention, the number average molecular weight of the double-ended epoxy polyether is 200-2000. The larger the molecular weight of the double-ended epoxy polyether, the worse the compatibility with the epoxy resin, which will lead to the failure of the thixotropic effect and even affect the performance of the epoxy resin, such as poor mechanical strength, poor toughness, and high glass transition temperature. For example, the number average molecular weight of the double-ended epoxy polyether can be any value among 200, 350, 400, 600, 800, 1000, 1200, 1400, 1600, 1800, 2000, etc. or any value therebetween, without special restrictions.

[0036] In a preferred embodiment of the present invention, the structure of the double-terminated epoxy polyether is shown in the following formula (1):

[0037] (CH2CHO)CH2O(CH2CH2O) a (CH2CHCH3O) b CH2(CHOCH2)(1)

[0038] Among them, a≥0, b≥0, 3≤a+b≤32.

[0039] In the present invention, the double-ended epoxy polyether contains polyethylene glycol segments (EO segments) and / or polypropylene glycol segments (PO segments), which contain abundant ether bonds and can form hydrogen bonds with each other or with the first thixotropic agent. Therefore, the hydrogen bond content in the epoxy resin composition of the present invention is high, the effects between hydrogen bonds are many and more complex, and the first thixotropic agent is a solid particle, the second thixotropic agent is a polymer, and the effects between the first thixotropic agent and the second thixotropic agent are more complex and diverse, so that the epoxy resin composition and the epoxy seam glue of the present invention have high thixotropy and low viscosity, which is more conducive to extrusion, filling and other operations. The double-ended epoxy polyether can be directly purchased from the market, such as polypropylene glycol diglycidyl ether XY207, polyethylene glycol diglycidyl ether XY205, XY215, XY225 of Suzhou Senfida Chemical Co., Ltd., polypropylene glycol diglycidyl ether D-1217 of Wuxi Kemik Electronic Materials Co., Ltd., and XY217 of Suzhou Qihang Biotechnology Co., Ltd.

[0040] In the present invention, the thixotropy of the epoxy resin composition can be tested for vertical sag according to the method of GB / T13477.6-2002. The vertical sag of the epoxy resin composition is measured to be no more than 2 mm, and the epoxy resin composition has good thixotropy.

[0041] In the present invention, the preparation of the epoxy resin composition is not particularly limited. A method may be as follows: adding the epoxy resin into a container, adding the first thixotropic agent, dispersing evenly at high speed, then adding the second thixotropic agent, stirring and dispersing evenly, and degassing to obtain the epoxy resin composition.

[0042] On the other hand, the present invention provides an epoxy seam sealant, which is composed of component A and component B;

[0043] The raw material components of component A include the epoxy resin composition described in any one of the above technical solutions;

[0044] Component B contains the curing agent.

[0045] Since the epoxy resin composition has good thixotropy, the epoxy seam sealant of the present invention also has good thixotropy, and has low viscosity, is easy to extrude, fill, and other operations, and is not prone to glue leakage.

[0046] In a preferred embodiment of the present invention, the weight proportion of the epoxy resin composition in component A is not less than 50%. For example, the weight proportion of the epoxy resin composition in component A can be any value of 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, etc. or any value in between, without special restrictions. In addition to the epoxy resin composition, component A can also contain fillers, pigments, additives, etc. The filler can be an organic filler or an inorganic filler, the pigment can be an organic pigment or an inorganic pigment, and the additive can be an anti-settling agent, a dispersant, a defoamer, a wetting agent, an anti-ultraviolet agent, an antioxidant, an anti-yellowing agent, a mildew inhibitor, a bactericide, etc.

[0047] In a preferred embodiment of the present invention, the molecular structure of the curing agent contains no less than 2 amino groups, and the amino groups are selected from primary amino groups and / or secondary amino groups. Both primary amino groups and secondary amino groups can undergo curing reaction with epoxy resins and form a cross-linked structure. For example, the curing agent can be 1,3-cyclohexanedimethylamine, 4,4'-diaminodicyclohexylmethane, 3,3'-diaminodicyclohexylmethane, 3,3'-dimethyl-4,4'diaminodicyclohexylmethane, N-aminoethylpiperazine, etc.

[0048] In the present invention, there is no particular limitation on the preparation of the epoxy sealant. A preparation method may be as follows: after the raw material components of component A are mixed and dispersed uniformly, component B is added, mixed uniformly, and the mixture is ready for use.

[0049] The technical solution of the present invention is further described and illustrated according to various embodiments below. Unless otherwise specified, the parts described in the following embodiments are parts by weight.

[0050] Example 1-8 Preparation of epoxy resin composition

[0051] Example 1

[0052] The epoxy resin composition is composed of 100 parts of epoxy resin E-51, 4 parts of fumed silica A200 of Evonik Degussa and 6 parts of double-terminated epoxy polypropylene glycol XY207. E-51 and A200 are added to a container, and high-speed dispersion is performed at 1500 rpm for 30 minutes, and then 5 parts of XY207 are added, and vacuum is drawn at -0.095 to -0.097 MPa for 30 minutes to obtain the epoxy resin composition.

[0053] Attached Figure 1 This is a photograph of the epoxy resin composition when it was sampled, and it can be seen that it has high thixotropy.

[0054] Example 2

[0055] The difference between this embodiment and embodiment 1 is that in embodiment 1, the amount of A200 is adjusted from 4 to 6. The other steps remain unchanged.

[0056] Example 3

[0057] The difference between this embodiment and embodiment 1 is that in embodiment 1, the amount of A200 is adjusted from 4 to 8. The other steps remain unchanged.

[0058] Example 4

[0059] The difference between this embodiment and embodiment 1 is that in embodiment 1, the amount of XY207 is adjusted from 6 to 4. The other steps remain unchanged.

[0060] Example 5

[0061] The difference between this embodiment and embodiment 1 is that in embodiment 1, the amount of XY207 is adjusted from 6 parts to 7 parts. The other steps remain unchanged.

[0062] Example 6

[0063] The difference between this embodiment and embodiment 1 is that in embodiment 1, the amount of XY207 is adjusted from 6 parts to 10 parts. The other steps remain unchanged.

[0064] Example 7

[0065] The difference between this embodiment and embodiment 1 is that in embodiment 1, XY207 is adjusted from 6 parts to 1 part. The other steps remain unchanged.

[0066] Example 8

[0067] The difference between this embodiment and embodiment 1 is that in embodiment 1, the amount of XY207 is adjusted from 6 parts to 3 parts. The other steps remain unchanged.

[0068] Comparative Example 1

[0069] The difference between this comparative example and Example 1 is that in Example 1, A200 is adjusted from 4 parts to 1 part. The other steps remain unchanged.

[0070] Comparative Example 2

[0071] The difference between this comparative example and Example 1 is that in Example 1, A200 is adjusted from 4 parts to 2.5 parts. The other steps remain unchanged.

[0072] Comparative Example 3

[0073] The difference between this comparative example and Example 1 is that in Example 1, XY207 is adjusted from 5 parts to 12 parts. The other steps remain unchanged.

[0074] Comparative Example 4

[0075] The difference between this comparative example and Example 1 is that in Example 1, XY207 is adjusted from 5 parts to 15 parts. The other steps remain unchanged.

[0076] Performance Testing

[0077] Appearance: After the epoxy resin composition to be tested is placed at 25°C for 24 hours, it is tilted at 45° to observe whether it flows.

[0078] Sag: Test vertical sag according to the method of GB / T13477.6-2002. The lower the vertical sag, the better the thixotropy.

[0079] The results are shown in Table 1 below.

[0080] Table 1

[0081]

[0082]

[0083] It can be seen from the data results in Table 1 that the epoxy resin composition of the present invention has good thixotropic properties within a relatively suitable weight range of the first thixotropic agent and the second thixotropic agent, and is in a paste-like, non-flowing state at room temperature.

[0084] The epoxy resin compositions of Examples 1-8 and Comparative Examples 1-4 were prepared into epoxy seam sealants according to the following formulas:

[0085] Component A: 60 parts of epoxy resin composition, 13.4 parts of titanium dioxide, 25 parts of 0.5 mm glitter powder, 1 part of dispersant BYK-103 and 0.6 parts of defoamer BYK-A535.

[0086] Component B: 4,4'-diaminodicyclohexylmethane.

[0087] The molar ratio of the epoxy groups in component A to the active hydrogen on the amino groups in component B is 1:1.1.

[0088] The performance test results are shown in Table 2 below.

[0089] Sedimentation stability: Take 800g of component A of the epoxy sealant to be tested, place it in a 1L transparent plastic bottle, seal it, and bake it in a 50℃ oven for 30 days. Observe the sedimentation of the pigment and filler. If there is sedimentation, measure the thickness of the bottom sediment. The thicker the sedimentation, the more severe the sedimentation and the worse the stability.

[0090] Impact toughness: After component A and component B are mixed evenly at room temperature, they are placed at 25°C for 48 hours for curing and tested according to the method of GB / T2567-2008.

[0091] Table 2 Epoxy Sealant Properties

[0092]

[0093]

[0094] It can be seen from the results in Table 2 that the epoxy sealant of the present invention has good thixotropy and can significantly improve the stability of pigments and fillers.

[0095] In addition, conventional potting was performed on the A components of the epoxy sealants made of the epoxy resin compositions of Examples 1-8 and Comparative Examples 1-4, respectively, and the potting was tested 100 times. The results of Examples 1-8 showed no leakage, while Comparative Example 1 had 13 cans of leakage, Comparative Example 2 had 4 cans of leakage, Comparative Example 3 had 7 cans of leakage, and Comparative Example 4 had 15 cans of leakage, indicating that there was no leakage of the epoxy sealant of the present invention during the potting process.

[0096] As described above, the basic principles, main features and advantages of the present invention are shown and described. Those skilled in the art should understand that the present invention is not limited by the above embodiments, which are only preferred embodiments of the present invention and cannot be used to limit the scope of the present invention. That is, equivalent changes and modifications made according to the scope of the present invention and the content of the specification should still be within the scope of the present invention. The scope of protection required by the present invention is defined by the attached claims and their equivalents.

Claims

1. An epoxy resin composition, characterized in that In parts by weight, it consists of 100 parts of epoxy resin, 3-10 parts of a first thixotropic agent and 1-10 parts of a second thixotropic agent; The first thixotropic agent is selected from one or a combination of fumed silica and organic bentonite; The second thixotropic agent is a double-terminal epoxy polyether.

2. The epoxy resin composition according to claim 1, characterized in that The fumed silica is hydrophilic fumed silica with a BET specific surface area of ​​not less than 100 m 2 / g.

3. The epoxy resin composition according to claim 1, characterized in that The weight proportion of the first thixotropic agent is 4-8 parts.

4. The epoxy resin composition according to claim 1, characterized in that The weight proportion of the second thixotropic agent is 3-8 parts.

5. The epoxy resin composition according to claim 1, characterized in that The number average molecular weight of the double-terminal epoxy polyether is 200-2000.

6. The epoxy resin composition according to claim 1, characterized in that The structure of the double-terminated epoxy polyether is shown in the following formula (1): (CH2CHO)CH2O(CH2CH2O) a (CH2CHCH3O) b CH2(CHOCH2)(1)wherein a≥0, b≥0, 3≤a+b≤32.

7. An epoxy seam sealant, characterized in that: It is composed of component A and component B; The raw material components of the A component include the epoxy resin composition according to any one of claims 1 to 6; The B component contains a curing agent.

8. The epoxy sealant according to claim 7, characterized in that: The weight proportion of the epoxy resin composition in the component A is not less than 50%.

9. The epoxy seam sealant according to claim 7, characterized in that: The molecular structure of the curing agent contains no less than 2 amino groups, and the amino groups are selected from primary amino groups and / or secondary amino groups.

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