Epoxy resin composition, epoxy resin adhesive and application

Abstract

The invention provides an epoxy resin composition, epoxy resin glue and application, the epoxy resin composition takes epoxy resin as a matrix, and at least one micron-sized filler such as silver powder, silica powder, fumed silica, carbon powder and ferroferric oxide powder is added; long-chain polysiloxane (polysiloxane is usually used for toughening) with the molecular weight of 800-2000 is added into the epoxy resin adhesive, so that the thixotropic index and the viscosity of the epoxy resin adhesive can be improved, the viscosity change of the epoxy resin adhesive used at normal temperature can be reduced, the wiredrawing phenomenon during use can be improved, and the working performance and the storage performance of the epoxy resin adhesive can be improved.

Description

Technical Field

[0001] The invention belongs to the field of polymer technology, and in particular relates to an epoxy resin composition, epoxy resin glue and application. Background Art

[0002] Viscosity and thixotropic index are important parameters for evaluating the rheological properties of adhesives, slurries, coatings, etc., and directly affect process performance. For adhesives, the viscosity of the glue needs to be moderate. If the viscosity is too low, it is easy to cause problems such as easy flow or dripping after application, difficulty in maintaining the shape, and easy sedimentation of fillers; if the viscosity is too high, it will affect the extrusion of the glue and make it difficult to discharge the glue. The thixotropic index refers to the degree of change in the rheological properties of a material under shear stress. It reflects the ability of the fluid to restore its original structure after the structure is destroyed under the action of shear force. It is one of the important parameters for measuring rheological properties.

[0003] The viscosity can be adjusted by changing the resin matrix or adding suitable fillers. Adding high-viscosity or low-viscosity resins can directly adjust the viscosity of the glue, but it is difficult to adjust the thixotropic index. Adding fillers, especially fumed silica, can effectively increase the viscosity and thixotropic index, but whether adding resins or fillers, it is difficult to achieve storage stability of the glue at room temperature, and sometimes even aggravates the viscosity change. The viscosity change of the glue per unit time is a very important parameter. If the viscosity changes too quickly, it will affect the storage period and it is difficult to ensure a sufficient application period.

[0004] Chinese patent CN103937257A discloses a silicone thixotropic agent containing modified polysiloxane and modified cyclosiloxane. After the modified polysiloxane containing specific functional groups is mixed with liquid silicone rubber, the thixotropy of the liquid silicone rubber can be improved to meet the requirements of specific application occasions such as mold-free packaging.

[0005] Chinese patent CN117777040A discloses a method for synthesizing a crystalline thixotropic agent containing isocyanate groups. Isocyanate and a linear monohydric alcohol are mixed in a specific ratio to generate a crystalline thixotropic agent containing isocyanate groups. The generated crystalline thixotropic agent containing isocyanate groups is well compatible with a polyurethane system, so that the prepared coating or adhesive has good thixotropic properties.

[0006] Chinese patent CN112979963A discloses a reactive organosilicon thixotropic agent, which is prepared by subjecting a phenyl-containing cyclic hydrogen-containing polysiloxane or a branched hydrogen-containing polysiloxane to a hydrosilylation reaction with an unsaturated polyether under specific conditions. The reactive organosilicon thixotropic agent can simultaneously impart stable thixotropic properties, high transparency, and excellent mechanical properties and adhesive properties to the organosilicon encapsulant. Summary of the invention

[0007] The first object of the present invention is to provide an epoxy resin composition.

[0008] To this end, the above-mentioned purpose of the present invention is achieved through the following technical solutions:

[0009] An epoxy resin composition comprises epoxy resin, characterized in that it also comprises long-chain polysiloxane with a molecular weight of 800-2000 and micrometer-sized filler. The long-chain polysiloxane with a molecular weight of 800-2000 is in liquid form.

[0010] While adopting the above technical solutions, the present invention may also adopt or combine the following technical solutions:

[0011] As a preferred technical solution of the present invention: the molecular structure of the long-chain polysiloxane is shown as follows:

[0012]

[0013] Wherein, the X group is one of an epoxy group, an amine group, a hydroxyl group, a thiol group, a methyl group, and a hydrogen atom;

[0014] R 1 It is one of methyl, ethyl, propyl, benzene ring, and hydrogen atom;

[0015] R 2 It is one of methyl, ethyl, propyl, benzene ring, and hydrogen atom.

[0016] The main chain of the long-chain polysiloxane is a polysiloxane chain with no branched siloxane repeating units. 1 With R 2 It can be the same or different.

[0017] As a preferred technical solution of the present invention: the mass percentage of the long-chain polysiloxane in the epoxy resin is not higher than 10%.

[0018] As a preferred technical solution of the present invention: the epoxy resin is a liquid epoxy resin, and the liquid epoxy resin is at least one of alicyclic epoxy resin, glycidyl ether epoxy resin, glycidyl ester epoxy resin, glycidyl amine epoxy resin, phenolic epoxy resin, and aliphatic epoxy resin.

[0019] As a preferred technical solution of the present invention: the micron-sized filler is at least one of silver powder, silicon powder, fumed silica, carbon powder, and ferrosoferric oxide powder.

[0020] As a preferred technical solution of the present invention: the D of the micron-sized filler 50 The particle size is greater than 1 micron.

[0021] As a preferred technical solution of the present invention: the epoxy resin composition further includes a curing agent, and the curing agent is at least one of an amine curing agent, an acid anhydride curing agent, a catalyst curing agent, and a polymer curing agent;

[0022] The amine curing agent is at least one of diethylenetriamine (DETA), triethylenetetramine (TEPA), tetraethylenepentamine, ethylenediamine, propylenediamine, hexamethylenediamine, 4,4-diaminodiphenyl sulfone, ketimine, cyanate-modified amine, and imidazole-modified amine;

[0023] The acid anhydride curing agent is at least one of phthalic anhydride, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride and methylhexahydrophthalic anhydride;

[0024] The catalyst curing agent is at least one of 2-ethyl-4-methylimidazole (EMI), 1-benzyl-2-methylimidazole (BMI), boron trifluoride amine complex, and amidine compounds;

[0025] The polymer curing agent is at least one of polyamide and polyurethane modified epoxy resin.

[0026] As a preferred technical solution of the present invention: the epoxy resin composition further includes an accelerator, and the accelerator is at least one of an imidazole accelerator, an amidine accelerator, a boron trifluoride complex, an organic metal compound, thiourea and its derivatives, an acid anhydride reaction accelerator, and a heterocyclic compound;

[0027] The imidazole accelerator is at least one of 2-ethyl-4-methylimidazole (EMI), 1-benzyl-2-methylimidazole (BMI), 2-phenylimidazole (PI), 2-methylimidazole (MI), and 1-cyanoethyl-2-ethyl-4-methylimidazole;

[0028] The amidine accelerator is at least one of diphenylamidine and benzylamidine;

[0029] The boron trifluoride complex is boron trifluoride monoethylamine (BF 3 ·MEA), boron trifluoride diethylamine (BF 3 · at least one of DEA);

[0030] The organometallic compound is at least one of organic compounds of calcium, magnesium, aluminum, titanium and zirconium metals;

[0031] The thiourea and its derivatives are at least one of thiourea and thiourea derivatives;

[0032] The acid anhydride reaction accelerator is at least one of aluminum isopropoxide, aluminum isooctoxide, benzoic acid, and p-toluenesulfonic acid;

[0033] The heterocyclic compound is at least one of Ullmann's base, a triazole compound and a tetrazole compound.

[0034] The second object of the present invention is to provide an epoxy resin adhesive prepared according to the epoxy resin composition described above.

[0035] Another object of the present invention is to provide an application of long-chain polysiloxane in regulating the viscosity, thixotropic index, and viscosity change of epoxy resin adhesive when used at room temperature.

[0036] The present invention provides an epoxy resin composition, epoxy resin glue and application thereof. The epoxy resin composition takes epoxy resin as a matrix, adds a curing agent and other auxiliary agents, adds at least one micron-sized filler selected from the group consisting of silver powder, silicon micropowder, fumed silica, carbon powder and ferroferric oxide powder, and adds a long-chain polysiloxane (polysiloxane is usually used for toughening) with a molecular weight of 800-2000. The thixotropic index of the epoxy resin glue can be increased, the viscosity of the epoxy resin glue can be increased, the viscosity change when used at room temperature can be reduced, the wire drawing phenomenon when used can be improved, and the operating performance and storage performance of the epoxy resin glue can be improved. DETAILED DESCRIPTION

[0037] The present invention is described in further detail with reference to specific examples.

[0038] 1. Test preparation

[0039] 1.1 Test materials

[0040]

[0041] 1.2 Performance Testing

[0042] Viscosity and thixotropic index: Use Brookfield rotational viscometer to test the viscosity of epoxy resin glue. Use 51# rotor, rotation speed of 0.5rpm and 5rpm, and test temperature of 25℃. After the sample is left at room temperature of 25℃ for 24 hours, the viscosity value is measured in the same way and the viscosity change at 5rpm is calculated. The thixotropic index uses the ratio of the viscosity at 0.5rpm to the viscosity at 5rpm.

[0043] Fineness: Use a scraper fineness meter to measure the maximum particle size in the sample. Take 2 mL of the sample on the surface of the fineness meter, use the scraper to smoothly scrape the surface of the fineness meter, and determine the maximum particle size in the sample based on the size mark corresponding to the starting position of the scratch.

[0044] 2. Experimental process

[0045] 2.1 Glue preparation process (taking Example 1 as an example):

[0046] Weigh 10 parts of epoxy resin EXA-835LV, 15 parts of methylhexahydrophthalic anhydride, 0.1 parts of 2E4MZ-CN, and 0.4 parts of HE-163EP-2, add them into a mixing kettle, mix at 800 rpm for 15 minutes, then add 63.75 parts of silver powder, disperse at 800 rpm for 15 minutes, then degas under vacuum (vacuum degree <-0.095 MPa) for 10 minutes, and discharge at normal pressure to obtain epoxy resin glue.

[0047] Table 1

[0048]

[0049] 2.2 Data Discussion:

[0050] Viscosity and thixotropic index: Example 1 is compared with Comparative Example 1, with other components being the same, and HR-163EP-2 with a mass percentage of 4% of epoxy resin is added to Example 1, and the 5rpm viscosity is increased from 6788cps to 10850cps, and the thixotropic index is increased from 4.10 to 5.65, and the 24h viscosity change at room temperature is reduced from 27% to 4.6%. Long-chain polysiloxane can increase the viscosity and thixotropic coefficient of epoxy resin glue and reduce the viscosity change at room temperature.

[0051] The curing agent added in Example 1 and Comparative Example 1 is methyl hexahydrophthalic anhydride, and the curing agent added in Example 3 and Comparative Example 2 is 4,4-diaminodiphenyl sulfone. The curing agent types are different. At the same time, referring to Example 3 and Comparative Example 2, Example 4 and Comparative Example 3, and Example 5 and Comparative Example 4, the fillers are silver powder, silicon powder, and fumed silica. Compared with the comparative examples (that is, Example 1 is compared with Comparative Example 1, Example 3 is compared with Comparative Example 2, Example 4 is compared with Comparative Example 3, and Example 5 is compared with Comparative Example 4), long-chain polysiloxane HR-163EP-2 is added, and the viscosity and thixotropic coefficient are both increased, while the viscosity change at room temperature for 24 hours is both decreased, indicating that long-chain polysiloxane plays the same role in different curing systems and filler systems.

[0052] In Example 5 and Comparative Example 5, compared with Comparative Example 4, HR-163EP-2 and TS-720 were added by 2% more epoxy resin mass, and the viscosity change at room temperature for 24 hours changed from 13% (Comparative Example 4) to 7.2% (Example 5) and 20% (Comparative Example 5), respectively. Therefore, compared with conventional thixotropic agents, specific polysiloxanes can not only increase the viscosity and thixotropic coefficient of epoxy resin glue, but also reduce the viscosity change at room temperature for 24 hours.

[0053] Fineness: In Comparative Example 6, compared with Examples 1 and 2, the addition amount of HR-163EP-2 is increased from less than 10% by mass of the epoxy resin to 20%, the viscosity is greatly increased, the thixotropic coefficient is increased to 6.43, and the viscosity change at 5rpm at room temperature for 24 hours is 2.3%, which is almost unchanged compared with 4.6% and 2.8% in Examples 1 and 2. However, the particle fineness is increased from 6 to 10 μm to 30 μm. The presence of large-sized particles can easily cause the rubber head to be blocked, affecting its use.

[0054] The above-mentioned specific implementation methods are used to explain the present invention and are only preferred embodiments of the present invention, rather than limiting the present invention. Any modifications, equivalent substitutions, improvements, etc. made to the present invention within the spirit of the present invention and the protection scope of the claims shall fall within the protection scope of the present invention.

Claims

1. An epoxy resin composition comprising an epoxy resin, characterized in that: Also included are long chain polysiloxanes with a molecular weight of 800-2000 and micron-sized fillers.

2. The epoxy resin composition according to claim 1, characterized in that: The molecular structure of the long-chain polysiloxane is shown below: Wherein, the X group is one of an epoxy group, an amine group, a hydroxyl group, a thiol group, a methyl group, and a hydrogen atom; R1 is one of methyl, ethyl, propyl, benzene ring, and hydrogen atom; R2 is one of a methyl group, an ethyl group, a propyl group, a benzene ring, and a hydrogen atom.

3. The epoxy resin composition according to claim 1 or 2, characterized in that: The mass percentage of the long-chain polysiloxane in the epoxy resin is not higher than 10%.

4. The epoxy resin composition according to claim 1, characterized in that: The epoxy resin is a liquid epoxy resin, and the liquid epoxy resin is at least one of alicyclic epoxy resin, glycidyl ether epoxy resin, glycidyl ester epoxy resin, glycidyl amine epoxy resin, phenolic epoxy resin, and aliphatic epoxy resin.

5. The epoxy resin composition according to claim 1, characterized in that: The micron-sized filler is at least one of silver powder, silicon powder, fumed silicon dioxide, carbon powder, and ferroferric oxide powder.

6. The epoxy resin composition according to claim 1 or 5, characterized in that: The D of the micron size filler 50 The particle size is greater than 1 micron.

7. The epoxy resin composition according to claim 1, characterized in that: The epoxy resin composition further includes a curing agent, wherein the curing agent is at least one of an amine curing agent, an acid anhydride curing agent, a catalyst curing agent, and a polymer curing agent; The amine curing agent is at least one of diethylenetriamine, triethylenetetramine, tetraethylenepentamine, ethylenediamine, propylenediamine, hexamethylenediamine, 4,4-diaminodiphenyl sulfone, ketimine, cyanate-modified amine, and imidazole-modified amine; The acid anhydride curing agent is at least one of phthalic anhydride, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride and methylhexahydrophthalic anhydride; The catalyst curing agent is at least one of 2-ethyl-4-methylimidazole, 1-benzyl-2-methylimidazole, boron trifluoride amine complex, and amidine compounds; The polymer curing agent is at least one of polyamide and polyurethane modified epoxy resin.

8. The epoxy resin composition according to claim 7, characterized in that: The epoxy resin composition further comprises an accelerator, which is at least one of an imidazole accelerator, an amidine accelerator, a boron trifluoride complex, an organic metal compound, thiourea and its derivatives, an acid anhydride reaction accelerator, and a heterocyclic compound; The imidazole accelerator is at least one of 2-ethyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 2-phenylimidazole, 2-methylimidazole, and 1-cyanoethyl-2-ethyl-4-methylimidazole; The amidine accelerator is at least one of diphenylamidine and benzylamidine; The boron trifluoride complex is at least one of boron trifluoride monoethylamine and boron trifluoride diethylamine; The organometallic compound is at least one of organic compounds of calcium, magnesium, aluminum, titanium and zirconium metals; The thiourea and its derivatives are at least one of thiourea and thiourea derivatives; The acid anhydride reaction accelerator is at least one of aluminum isopropoxide, aluminum isooctoxide, benzoic acid, and p-toluenesulfonic acid; The heterocyclic compound is at least one of Ullmann base, triazole compound and tetrazole compound.

9. The epoxy resin glue prepared from the epoxy resin composition according to any one of claims 1 to 8.

10. The application of long-chain polysiloxane in regulating the viscosity, thixotropic index and viscosity change of epoxy resin adhesive during use at room temperature.

Images