Room-temperature-curing high-temperature-resistant heat-conducting epoxy glue and preparation method thereof

Abstract

The invention relates to the technical field of epoxy adhesives, in particular to a room-temperature-curing high-temperature-resistant heat-conducting epoxy adhesive and a preparation method thereof. Comprising a component A and a component B. The component A comprises, by weight, 60-135 parts of epoxy resin, 10-30 parts of a flexibilizer, 30-85 parts of a filler and 2-15 parts of an auxiliary agent, and the component B comprises, by weight, 40-90 parts of an amine curing agent, 10-30 parts of high-temperature-resistant resin, 30-60 parts of a filler and 2-12 parts of an additive. The epoxy resin comprises bisphenol A epoxy resin, novolac epoxy resin, polyurethane modified resin and multifunctional epoxy resin. The product has good mechanical properties and excellent temperature resistance, and the toughening agent and the resin powder are reasonably matched to ensure that the product has excellent impact resistance and temperature resistance. A plurality of amine curing agents are reasonably matched, so that the product can be cured at room temperature and used at high temperature, and meanwhile, the temperature resistance of the product is further improved by adding the high-temperature-resistant resin.

Description

Technical Field

[0001] The present invention relates to the technical field of epoxy adhesives, and in particular to a room temperature curing high temperature resistant heat conductive epoxy adhesive and a preparation method thereof. Background Art

[0002] Epoxy adhesives are mainly composed of two core components: epoxy resin and curing agent. Although they have excellent bonding properties, they generally have poor temperature resistance. In order to improve temperature resistance, a high-temperature curing process is often required, which greatly limits the convenience of its application, because it is difficult to achieve complete curing at room temperature, and thus has no practical use value. In addition, the thermal conductivity of epoxy resin cured products is often only in the low range of 0.2-0.3W / (m·K), which means that its performance in heat dissipation is not satisfactory. This defect is particularly prominent for high-end application fields that require efficient heat dissipation. In summary, temperature resistance limitations and insufficient thermal conductivity have become key factors restricting the widespread application of epoxy adhesives in high-end fields such as aerospace, precision electronics, etc.

[0003] Chinese invention patent CN102703012B discloses a thermally conductive COB epoxy adhesive and its preparation method, which is composed of the following raw materials in percentage by total weight: epoxy resin accounts for 20-40%, diluent accounts for 2-10%, thermally conductive filler accounts for 25-73%, coupling agent accounts for 0-1%, dye accounts for 0-1%, defoamer accounts for 0-1%, thixotropic agent accounts for 1-3%, curing agent accounts for 2-5%, and curing accelerator accounts for 1-3%. The thermally conductive COB epoxy adhesive prepared by the invention protects the various functions of the chip in application, and can also improve the computing speed, extend the service life of the chip, and make the operation of the chip more stable, but the thermal conductivity of the invention needs to be improved. Summary of the invention

[0004] The first aspect of the present invention provides a room temperature curing high temperature resistant thermal conductive epoxy adhesive, comprising component A and component B, wherein, by weight, component A comprises: 60-135 parts of epoxy resin, 10-30 parts of toughening agent, 30-85 parts of filler, and 2-15 parts of auxiliary agent; component B comprises: 40-90 parts of amine curing agent, 10-30 parts of high temperature resistant resin, 30-60 parts of filler, and 2-12 parts of additive; the epoxy resin comprises bisphenol A epoxy resin, phenolic epoxy resin, polyurethane modified resin, and multifunctional epoxy resin.

[0005] The applicant has found that the addition of bisphenol A epoxy resin, phenolic epoxy resin, polyurethane modified resin and multifunctional epoxy resin at the same time can improve the mechanical properties and temperature resistance of epoxy adhesive. It may be that bisphenol A epoxy resin provides good adhesion and mechanical properties to the adhesive, phenolic epoxy resin and multifunctional epoxy provide good heat resistance to the adhesive, and polyurethane modified epoxy resin provides good flexibility and adhesion to the adhesive. Further research has found that the weight ratio of bisphenol A epoxy resin, phenolic epoxy resin, polyurethane modified resin and multifunctional epoxy resin is (15-30): (20-40): (5-20): (20-40), which can further improve the mechanical properties and reach 13MPa in 24 hours. Further research found that the weight ratio of bisphenol A epoxy resin, phenolic epoxy resin, polyurethane modified resin and multifunctional epoxy resin is 3:(4-4.5):(1-1.5):(4-4.5), which can further improve the mechanical strength of epoxy adhesive at high temperatures. The tensile strength at 200°C can still reach 5MPa, which meets the requirements of bonding and fixing various high-temperature resistant components or use as a heat dissipation coating.

[0006] The weight ratio of the bisphenol A epoxy resin, the novolac epoxy resin, the polyurethane modified resin and the multifunctional epoxy resin is (15-30):(20-40):(5-20):(20-40).

[0007] Preferably, the weight ratio of the bisphenol A epoxy resin, the novolac epoxy resin, the polyurethane modified resin and the multifunctional epoxy resin is 3:(4-4.5):(1-1.5):(4-4.5).

[0008] The average epoxy value of the bisphenol A epoxy resin is 0.30-0.60 eq / 100 g.

[0009] Preferably, the average epoxy value of the bisphenol A epoxy resin is 0.40-0.55 eq / 100 g.

[0010] Further preferably, the bisphenol A epoxy resin includes at least one of the following brands: E-51, E44.

[0011] The epoxy equivalent of the novolac epoxy resin is 150-200 g / mol.

[0012] Preferably, the epoxy equivalent of the novolac epoxy resin is 165-190 g / mol.

[0013] Further preferably, the phenolic epoxy resin includes at least one of the following brands: F-51, SNE-625.

[0014] The average epoxy value of the polyurethane modified resin is 0.30-0.60 eq / 100 g.

[0015] Preferably, the average epoxy value of the polyurethane modified resin is 0.40-0.60 eq / 100g.

[0016] Further preferably, the polyurethane modified resin includes at least one of the following brands: SL3401, SL3451.

[0017] The functionality of the multifunctional epoxy resin is 3-5.

[0018] Preferably, the functionality of the multifunctional epoxy resin is 3-4.

[0019] Further preferably, the multifunctional epoxy resin includes at least one of the following brands: SWE-85, AG80 resin, AFG90 resin.

[0020] The amine curing agent includes vinylamine, alicyclic amine and aromatic amine.

[0021] Preferably, the ethyleneamine is at least one of diethylenetriamine, triethylenetetramine, pentaethylenehexamine, tetraethylenepentamine and divinylpropylamine.

[0022] Preferably, the alicyclic amine includes at least one of isophorone diamine, 1,3-cyclohexanedimethylamine, 4,4-diaminodicyclohexylmethane, N-aminoethylpiperazine, and menthane diamine.

[0023] Preferably, the aromatic amine is at least one of diaminodiphenylmethane, diaminodiphenyl sulfone, meta-xylylenediamine and meta-phenylenediamine.

[0024] Preferably, the high temperature resistant resin comprises bismaleimide resin.

[0025] The filler includes at least one of aluminum oxide, iron oxide, magnesium oxide, zinc oxide, boron nitride, silicon carbide, calcium silicate whisker, and fumed silicon dioxide.

[0026] Preferably, the filler comprises aluminum oxide, zinc oxide, silicon carbide and calcium silicate whiskers, and the weight ratio of the aluminum oxide, zinc oxide, silicon carbide and calcium silicate whiskers is 3:(1-3):(1-2):(1-2).

[0027] Preferably, the toughening agent includes at least one of carboxyl-terminated liquid nitrile rubber, Qishi toughening agent, and PEEK resin powder.

[0028] Further preferably, the toughening agent includes Qishi toughening agent and PEEK resin powder, and the weight ratio of the Qishi toughening agent to the PEEK resin powder is 1:(0.8-1.2).

[0029] The filler includes at least one of fumed silica, silica powder, mica powder and calcined alumina.

[0030] The auxiliary agent includes at least one of a coupling agent, a rheological agent, a color paste and a catalyst.

[0031] The additives include coupling agents, catalysts and curing accelerators.

[0032] The coupling agent includes at least one of KH560, KH570 and KH580.

[0033] The rheological agent includes A7466.

[0034] The curing accelerator includes at least one of aminoethylpiperazine and DMP-30.

[0035] The catalyst includes at least one of triethanolamine, triphenylphosphine and dibutyltin dilaurate.

[0036] A second aspect of the present invention provides a method for preparing a room temperature curing high temperature resistant thermally conductive epoxy adhesive, comprising the following steps:

[0037] Mix bisphenol A epoxy resin, phenolic epoxy resin, and polyurethane modified resin, add multifunctional epoxy resin, toughening agent, and auxiliary agent, and then add filler to obtain component A;

[0038] The aromatic amine and the high temperature resistant resin are heated and mixed, and after cooling, vinylamine, alicyclic amine and additives are added, and after mixing, fillers are added and stirred evenly to obtain component B.

[0039] Beneficial Effects

[0040] 1. Adding bisphenol A epoxy resin, phenolic epoxy resin, polyurethane modified resin and multifunctional epoxy resin at the same time can improve the mechanical properties and temperature resistance of epoxy adhesive.

[0041] 2. The weight ratio of bisphenol A epoxy resin, phenolic epoxy resin, polyurethane modified resin and multifunctional epoxy resin is (15-30):(20-40):(5-20):(20-40), which can further improve the mechanical properties and reach 13MPa in 24h.

[0042] 3. The weight ratio of bisphenol A epoxy resin, phenolic epoxy resin, polyurethane modified resin and multifunctional epoxy resin is 3:(4-4.5):(1-1.5):(4-4.5), which can further improve the mechanical strength of epoxy adhesive at high temperature. The tensile strength at 200°C can still reach 5MPa, which can meet the bonding and fixation of various high-temperature resistant components or be used as a heat dissipation coating.

[0043] 4. Fillers include aluminum oxide, zinc oxide, silicon carbide and calcium silicate whiskers to reduce the shrinkage of epoxy adhesive during curing and improve the mechanical properties, heat resistance, thermal conductivity and thixotropy of the product.

[0044] 5. The weight ratio of aluminum oxide, zinc oxide, silicon carbide and calcium silicate whiskers is limited to 3: (1-3): (1-2):

[0045] (1-2), while maintaining the mechanical properties, the thermal conductivity can be increased to 1.5 W / (m·K).

[0046] 6. By adding specific auxiliaries and additives, the reactivity of the product can be improved, the curing temperature of the product can be reduced, and it can be cured at room temperature.

[0047] 7. By adding specific toughening agents, the brittleness of the adhesive can be improved, the impact resistance of the adhesive can be improved, and the adhesion to the substrate can be improved. DETAILED DESCRIPTION

[0048] Examples 1-3, Comparative Examples 1-4

[0049] A room temperature curing high temperature resistant thermal conductive epoxy adhesive, composed of component A and component B, in parts by weight, wherein component A is shown in Table 1, and component B is shown in Table 2.

[0050] Table 1

[0051]

[0052]

[0053] Table 2

[0054]

[0055]

[0056] Examples 1-3, Comparative Examples 1-3

[0057] A method for preparing a room temperature curing high temperature resistant thermal conductive epoxy adhesive comprises the following steps:

[0058] Mix bisphenol A epoxy resin, phenolic epoxy resin and polyurethane modified resin, heat to 150°C and start stirring, add toughening agent for pre-reaction for 3 hours, cool to below 50°C, add auxiliary agent and multifunctional epoxy resin, mix well, add filler, stir well to mix auxiliary agent, add filler and mix well to obtain component A;

[0059] First, add aromatic amine, high temperature resistant resin and dibutyltin dilaurate into a reaction container, start stirring and react for 3 hours, then add ethyleneamine, alicyclic amine and additives, stir evenly, then add filler, and then stir evenly to obtain component B.

[0060] Comparative Example 4

[0061] A method for preparing a room temperature curing high temperature resistant thermal conductive epoxy adhesive comprises the following steps:

[0062] Mix bisphenol A epoxy resin, phenolic epoxy resin and polyurethane modified resin, heat to 150°C and start stirring, add toughening agent for pre-reaction for 3 hours, cool to below 50°C, add auxiliary agent and multifunctional epoxy resin, mix well, add filler, stir well to mix auxiliary agent, add filler and mix well to obtain component A;

[0063] Aromatic amine, high temperature resistant resin, dibutyltin dilaurate, ethyleneamine, alicyclic amine, additives and fillers are added into a reaction container, and the reaction is stirred for 3 hours to obtain component B.

[0064] Performance Testing Methods

[0065] The A and B components in the embodiment and the comparative example were mixed at a weight ratio of 4:1 and then the performance test was carried out. The test data are listed in Table 3.

[0066] Appearance: Component A of the embodiment and comparative example is a black viscous paste, and component B is a brown-yellow paste.

[0067] Performance test data

[0068] Table 3

[0069]

Claims

1. A room temperature curing high temperature resistant thermal conductive epoxy adhesive, characterized in that: The invention comprises component A and component B. Component A comprises, by weight, 60-135 parts of epoxy resin, 10-30 parts of toughening agent, 30-85 parts of filler and 2-15 parts of auxiliary agent; component B comprises 40-90 parts of amine curing agent, 10-30 parts of high temperature resistant resin, 30-60 parts of filler and 2-12 parts of additive; the epoxy resin comprises bisphenol A epoxy resin, phenolic epoxy resin, polyurethane modified resin and multifunctional epoxy resin.

2. The room temperature curing high temperature resistant thermal conductive epoxy adhesive according to claim 1, characterized in that: The amine curing agent includes vinylamine, alicyclic amine and aromatic amine.

3. The room temperature curing high temperature resistant thermal conductive epoxy adhesive according to claim 2, characterized in that: The weight ratio of the bisphenol A epoxy resin, the novolac epoxy resin, the polyurethane modified resin and the multifunctional epoxy resin is (15-30):(20-40):(5-20):(20-40).

4. The room temperature curing high temperature resistant thermal conductive epoxy adhesive according to claim 3, characterized in that: The average epoxy value of the bisphenol A epoxy resin is 0.30-0.60 eq / 100 g.

5. The room temperature curing high temperature resistant thermal conductive epoxy adhesive according to claim 4, characterized in that: The epoxy equivalent of the novolac epoxy resin is 150-200 g / mol.

6. The room temperature curing high temperature resistant thermal conductive epoxy adhesive according to claim 5, characterized in that: The average epoxy value of the polyurethane modified resin is 0.30-0.60 eq / 100 g.

7. The room temperature curing high temperature resistant thermal conductive epoxy adhesive according to claim 6, characterized in that: The functionality of the multifunctional epoxy resin is 3-5.

8. The room temperature curing high temperature resistant thermal conductive epoxy adhesive according to claim 2, characterized in that: The filler includes at least one of aluminum oxide, iron oxide, magnesium oxide, zinc oxide, boron nitride, silicon carbide, calcium silicate whisker, and fumed silicon dioxide.

9. The room temperature curing high temperature resistant thermal conductive epoxy adhesive according to claim 8, characterized in that: The auxiliary agent includes at least one of a coupling agent, a rheological agent, a color paste and a catalyst.

10. A method for preparing the room temperature curing high temperature resistant thermal conductive epoxy adhesive according to any one of claims 2 to 9, characterized in that: The following steps are involved: Mix bisphenol A epoxy resin, phenolic epoxy resin, and polyurethane modified resin, add multifunctional epoxy resin, toughening agent, and auxiliary agent, and then add filler to obtain component A; The aromatic amine and the high temperature resistant resin are heated and mixed, and after cooling, vinylamine, alicyclic amine and additives are added, and after mixing, fillers are added, and the mixture is stirred evenly to obtain component B.

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