A room temperature curing high temperature resistant two-component epoxy structural adhesive and its application

Abstract

The present invention belongs to the technical field of epoxy adhesives. A room temperature curing high temperature resistant two-component epoxy structural adhesive is composed of component A and component B, wherein the volume ratio of component A to component B is (1-2): 1; component A includes the following raw materials by weight percentage: 70-90% epoxy resin, 10-25% toughening agent, 1-3% silane coupling agent, and the sum of the weight percentages of the raw materials in component A is 100%; component B includes the following raw materials by weight percentage: 50-85% modified polyether amine, 10-30% modified alicyclic amine, 1-5% modified imidazole curing agent, 1-3% silane coupling agent, 1-10% tertiary amine accelerator, and the sum of the weight percentages of the raw materials in component B is 100%. The structural adhesive of the present invention has high bonding strength, high temperature resistance and good high temperature aging performance, and can be used for bonding the galvanized steel bottom plate of the FDM printer and the magnet, meeting the requirements of FDM printer assembly bonding.

Description

Technical Field

[0001] The invention belongs to the technical field of epoxy adhesives, and specifically relates to a room temperature curing and high temperature resistant two-component epoxy structural adhesive and an application thereof. Background Art

[0002] With the development of additive manufacturing technology, fused deposition modeling (FDM) printers have become increasingly popular in industrial and personal applications. FDM printers gradually build complex three-dimensional structures by heating thermoplastic materials and depositing them layer by layer through an extruder. This technology has the advantages of high flexibility, short production cycle and high design freedom, and is widely used in prototyping, functional testing and small batch production.

[0003] In the structural design of FDM printers, the base plate is an important component in the printing process. Its stability and durability directly affect the printing quality and the precision of the finished product. Existing base plates are usually made of galvanized sheet materials and bonded and fixed with magnets using traditional two-component epoxy adhesives. Although this connection method can meet basic bonding requirements to a certain extent, it gradually exposes some shortcomings in actual applications, affecting the overall performance and service life of FDM printers.

[0004] First, the high temperature resistance of existing epoxy adhesives is insufficient. During the use of FDM printers, the heat source causes the base plate and adhesive to face high temperatures, and the base plate often needs to withstand continuous operation at a temperature of about 100°C; however, the existing toughened epoxy two-component structural adhesive has limited tolerance in high temperature environments, which can easily lead to softening, failure or shedding of the bonding interface, affecting the printing quality and the stability of the base plate. Secondly, the bonding strength of existing epoxy adhesives is unstable. Although existing epoxy adhesives can provide strong adhesion during initial bonding, their bonding strength may gradually decrease under the action of high temperature and multiple thermal cycles, thereby affecting the stability of printing and the service life of the base plate. In addition, the curing time of existing epoxy adhesives is long, which greatly limits production efficiency and increases production cycle and cost when the base plate needs to be quickly assembled during the production and assembly process of FDM printers.

[0005] Therefore, it is particularly important to develop a two-component epoxy structural adhesive that can cure quickly at room temperature, has excellent high temperature resistance, high-strength bonding ability, and good adaptability to high temperature environments. This will greatly improve the overall performance and service life of FDM printers and meet more demanding application requirements. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a two-component epoxy structural adhesive that can be used for bonding the galvanized steel base plate of an FDM printer to a magnet. The structural adhesive not only needs to be able to cure quickly at room temperature, but also needs to maintain high bonding strength and structural stability in a high temperature environment to meet the working requirements of the FDM printer under high temperature conditions.

[0007] The technical solution adopted by the present invention to solve the above problems is as follows:

[0008] A room temperature curing high temperature resistant two-component epoxy structural adhesive, comprising a component A and a component B, wherein the volume ratio of the component A to the component B is (1-2):1;

[0009] The component A comprises the following raw materials in percentage by weight: 70-90% epoxy resin, 10-25% toughening agent, 1-3% silane coupling agent, and the sum of the weight percentages of the raw materials in the component A is 100%;

[0010] The B component comprises the following raw materials in percentage by weight: 50-85% of modified polyether amine, 10-30% of modified alicyclic amine, 1-5% of modified imidazole curing agent, 1-3% of silane coupling agent, and 1-10% of tertiary amine accelerator. The sum of the weight percentages of the raw materials in the B component is 100%.

[0011] Furthermore, the epoxy resin is a mixture of bisphenol A epoxy resin and novolac epoxy resin, and the mass ratio of the bisphenol A epoxy resin to the novolac epoxy resin is (2:1) to (3:1).

[0012] Furthermore, the toughening agent is at least one of a core-shell toughening resin and a phenol-terminated isocyanate.

[0013] Furthermore, the core-shell toughening resin is a core-shell structure polymer with styrene-butadiene rubber or polybutadiene rubber as the core and polymethacrylate as the shell.

[0014] Specifically, the core-shell toughening resin may be selected from MZ-100, MZ-120, MZ-200, MX-125 of Kaneka Chemical Co., Ltd., Paraloid 2600, Paraloid 2650A of Rohm and Haas Chemical Co., but is not limited thereto.

[0015] Furthermore, the phenol-terminated isocyanate is a terminal isocyanate polymer obtained by reacting polypropylene glycol with a weight average molecular weight of 1000 to 2000 with toluene diisocyanate.

[0016] Specifically, the phenol-terminated isocyanate may be Desmocap 11 and Desmocap 14 from Covestro, or Trixene BI7771 and Trixene BI7774 from Lanxess, but is not limited thereto.

[0017] Preferably, the silane coupling agent is 3-glycidyloxypropyltrimethoxysilane.

[0018] Preferably, the modified polyetheramine is an adduct obtained by reacting a difunctional or trifunctional polyetheramine having a weight average molecular weight of 200 to 1000 with a bisphenol A epoxy resin in a mass ratio of 5:(1 to 3).

[0019] Preferably, the preparation method of the modified polyetheramine comprises: mixing a difunctional or trifunctional polyetheramine with a bisphenol A epoxy resin in a mass ratio of 5:(1-3), and reacting at 90° C. for 120 min.

[0020] More preferably, the modified polyetheramine is an adduct of one or a mixture of polyetheramine D-230, polyetheramine D-400, polyetheramine T-403 and bisphenol A epoxy resin.

[0021] Preferably, the modified alicyclic amine is an adduct obtained by mixing alicyclic diamine and bisphenol A epoxy resin in a mass ratio of 5:(2-5).

[0022] Preferably, the alicyclic diamine is at least one of isophoronediamine, 1,3-cyclohexanedimethylamine, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, and 4,4'-diaminodicyclohexylmethane.

[0023] Preferably, the preparation method of the modified alicyclic amine comprises: mixing alicyclic diamine and bisphenol A epoxy resin in a mass ratio of 5:(2-5), and reacting at 60° C. for 90 minutes.

[0024] Preferably, the modified imidazole curing agent is prepared by reacting imidazole with monofunctional glycidyl ether, wherein the mass ratio of the imidazole to the monofunctional glycidyl ether is (1.1-1.3):1.

[0025] Preferably, the preparation method of the modified imidazole curing agent comprises: adding imidazole into a reactor, then heating to 100° C., slowly adding monofunctional glycidyl ether within 1 hour after the imidazole is completely dissolved, and continuing the reaction for 2 hours after the addition is completed.

[0026] More preferably, the imidazole is 2-ethyl-4-methylimidazole.

[0027] More preferably, the monofunctional glycidyl ether is cardanol glycidyl ether.

[0028] In the above technical solution, the modified imidazole curing agent can not only promote curing, effectively reduce the operation time and improve production efficiency, but also improve the temperature resistance and high temperature aging resistance of the adhesive.

[0029] Furthermore, the tertiary amine accelerator is at least one of 2,4,6-tris(dimethylaminomethyl)phenol, N,N-dimethyldipropylenetriamine, and aminoethylpiperazine.

[0030] Furthermore, the room temperature curing high temperature resistant two-component epoxy structural adhesive further includes 0-20% filler, 0-5% thixotropic agent, and 0-1% defoaming agent.

[0031] Preferably, the filler can be at least one of nano calcium carbonate, silicon powder, talcum powder, kaolin and barium sulfate, but is not limited thereto.

[0032] Preferably, the thixotropic agent may be at least one of fumed silica and bentonite, but is not limited thereto.

[0033] Preferably, the fumed silica may be Evonik AEROSIL R202, AEROSIL R972, or Cabot TS-720, but is not limited thereto.

[0034] The present invention also provides the use of the room temperature curing high temperature resistant two-component epoxy structural adhesive in bonding the bottom plate of an FDM printer. The two-component epoxy structural adhesive of the present invention has certain high temperature resistance and high temperature aging performance, and can be used for bonding the galvanized steel bottom plate of an FDM printer to a magnet.

[0035] The present invention has the following beneficial effects:

[0036] The two-component epoxy structural adhesive of the present invention uses core-shell resin / phenol blocked isocyanate as a toughening agent, uses modified polyetheramine as a curing agent, and simultaneously adds phenolic epoxy resin and modified alicyclic amine to obtain a higher Tg, thereby improving the bonding strength of the structural adhesive at high temperatures. In addition, by adding modified imidazole, the heat aging resistance is improved, the initial curing speed can be increased, and the operation time can be reduced.

[0037] The two-component epoxy structural adhesive of the present invention can be quickly cured at room temperature and has a short operating time; the two-component epoxy structural adhesive of the present invention has good bonding strength to galvanized steel, and at the same time has good high temperature resistance and high temperature aging resistance, can maintain high bonding strength and structural stability in a long-term high temperature environment, can adapt to the working requirements of FDM printers under high temperature conditions, and can be used for bonding the galvanized steel base plate of the FDM printer to the magnet. DETAILED DESCRIPTION

[0038] In order to make the technical problems, technical solutions and technical advantages to be solved by the present invention clearer, the following will be described in detail with reference to specific examples, but the protection scope of the present invention is not limited to the following specific embodiments, and the described embodiments are only part of the embodiments of the present invention, not all of the embodiments, and are not limitations of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention.

[0039] Unless otherwise defined, all professional terms used below have the same meanings as those generally understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0040] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0041] The raw materials in the embodiments and comparative examples can be obtained from commercial sources, as follows:

[0042] NPEL-128, bisphenol A epoxy resin (epoxy equivalent weight 184-190 g / Eq), was purchased from Nan Ya Epoxy Resin Company.

[0043] DEN 431, phenolic epoxy resin (epoxy equivalent weight 172-179 g / Eq), was purchased from Dow.

[0044] MZ-120, a core-shell toughened resin with styrene-butadiene rubber as the core and polymethacrylate as the shell, was purchased from Kaneka Chemical Co., Ltd.

[0045] Desmocap 11, an isocyanate terminated with nonylphenol, was purchased from Covestro.

[0046] WD-50, silane coupling agent (3-aminopropyltriethoxysilane), was purchased from Hubei Wuda Organic Silicon New Materials Co., Ltd.

[0047] WD-60, silane coupling agent (3-glycidyloxypropyltrimethoxysilane), was purchased from Hubei Wuda Organic Silicone New Materials Co., Ltd.

[0048] Ancamine K54, 2,4,6-tris(dimethylaminomethyl)phenol, a tertiary amine curing accelerator, was purchased from Evonik, Germany.

[0049] Preparation Example 1:

[0050] Preparation of modified polyetheramine 1: 100 g of polyetheramine D-230 was mixed with 50 g of epoxy resin NPEL-128 and reacted at 90° C. for 120 min.

[0051] Preparation Example 2:

[0052] Preparation of modified polyetheramine 2: 100 g of polyetheramine T-403 was mixed with 24 g of epoxy resin NPEL-128 and reacted at 90° C. for 120 min.

[0053] Preparation Example 3:

[0054] Preparation of modified alicyclic amine: 100 g of 1,3-cyclohexanedimethylamine was mixed with 80 g of epoxy resin NPEL-128 and reacted at 60° C. for 90 min.

[0055] Preparation Example 4:

[0056] Preparation of modified imidazole curing agent: In a four-necked flask equipped with a stirrer, a condenser, a constant pressure dropping funnel and a thermometer, add 120g of 2-ethyl-4-methylimidazole (2E4MZ) and heat to 100°C. After 2E4MZ is completely dissolved, slowly add 250g of cardanol glycidyl ether within 1 hour. After the addition is completed, continue the reaction for 2 hours.

[0057] Examples 1 to 4 and Comparative Examples 1 to 2 respectively provide a two-component epoxy structural adhesive, and the component contents are shown in Table 1, unit: mass percentage (%).

[0058] Table 1:

[0059]

[0060] Example 1 A two-component epoxy structural adhesive was prepared by the following method:

[0061] (1) Preparation of component A:

[0062] The epoxy resin and toughening agent were mixed and stirred at 25°C for 10 minutes; then the temperature was raised to 60°C and maintained for 60 minutes; after the mixture was cooled to room temperature, the remaining components were added and the mixture was mixed evenly at room temperature by vacuum stirring and degassing at 1800 rpm with a star-type high-speed mixer for 3 minutes.

[0063] (2) Preparation of component B:

[0064] The modified polyetheramine, modified alicyclic amine and modified imidazole curing agent were mixed and heated to 80°C, and then a tertiary amine curing accelerator was added and stirred for 10 minutes; the resulting mixture was then heated to 80°C and maintained for 90 minutes; after the mixture was cooled to room temperature, the remaining components were added, and the mixture was mixed evenly at room temperature using a star-type high-speed mixer at 1800 rpm for 3 minutes under vacuum stirring and degassing.

[0065] (3) Mixing of component A and component B:

[0066] Pour component A and component B into 400ml (volume ratio A:B=2:1) ​​one-piece rubber cartridges respectively, assemble the static mixing tube onto the rubber cartridge, extrude with a manual glue gun and evenly apply onto the test piece, and cure at room temperature 25°C for 3 days.

[0067] The methods for preparing two-component epoxy structural adhesives in Examples 2 to 4 and Comparative Examples 1 to 2 can be obtained in the same manner. If there are components that are not added, they can be deleted in the corresponding preparation steps.

[0068] The performance of the two-component epoxy structural adhesives prepared in Examples 1 to 4 and Comparative Examples 1 to 2 was tested, and the specific method is as follows:

[0069] 1. Operation time. Tested according to standard GB / T 7123.1-2015.

[0070] 2. Tensile shear strength: tested in accordance with standard GB / T 7124-2008, the base material is galvanized steel.

[0071] 2.1 High temperature tensile shear strength. After the bond is fully cured, the tensile shear strength of the test piece is tested at 100°C.

[0072] 2.2 High temperature aging test: After the bonding is fully cured, the test piece is aged at 100°C for 1000 hours to test the tensile shear strength of the test piece.

[0073] 3. Glass transition temperature Tg. Tested according to standard GB / T 19466.2-2004.

[0074] The test results are shown in Table 2.

[0075] Table 2: Performance test results of Examples 1 to 4 and Comparative Examples 1 to 2

[0076]

[0077]

[0078] It can be seen from Table 2 that, compared with Comparative Example 1, after adding the modified imidazole curing agent, the thermal aging performance of the obtained structural adhesive at 100°C is significantly improved in Example 2; compared with Comparative Example 2, after adding the phenolic resin and the modified alicyclic amine, the obtained structural adhesive still has a high bonding strength at a high temperature of 100°C in Example 2.

[0079] The two-component epoxy structural adhesive prepared in the embodiment of the present invention has good bonding strength to galvanized steel at room temperature, and has good high temperature resistance and high temperature aging resistance. It can adapt to the working requirements of FDM printers under high temperature conditions and has good application prospects in the field of FDM production and assembly.

[0080] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0081] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0082] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A room temperature curing high temperature resistant two-component epoxy structural adhesive, characterized in that: It is composed of component A and component B, wherein the volume ratio of component A to component B is (1-2):1; The component A comprises the following raw materials in percentage by weight: 70-90% epoxy resin, 10-25% toughening agent, 1-3% silane coupling agent, and the sum of the weight percentages of the raw materials in the component A is 100%; The B component comprises the following raw materials in percentage by weight: 50-85% of modified polyether amine, 10-30% of modified alicyclic amine, 1-5% of modified imidazole curing agent, 1-3% of silane coupling agent, and 1-10% of tertiary amine accelerator. The sum of the weight percentages of the raw materials in the B component is 100%.

2. The room temperature curing high temperature resistant two-component epoxy structural adhesive according to claim 1, characterized in that: The epoxy resin is a mixture of bisphenol A epoxy resin and novolac epoxy resin, and the mass ratio of the bisphenol A epoxy resin to the novolac epoxy resin is (2:1) to (3:1).

3. The room temperature curing high temperature resistant two-component epoxy structural adhesive according to claim 1, characterized in that: The toughening agent is at least one of a core-shell toughening resin and a phenol-terminated isocyanate.

4. The room temperature curing high temperature resistant two-component epoxy structural adhesive according to claim 3, characterized in that: The core-shell toughening resin is a core-shell structure polymer with styrene-butadiene rubber or polybutadiene rubber as the core and polymethacrylate as the shell.

5. The room temperature curing high temperature resistant two-component epoxy structural adhesive according to claim 3, characterized in that: The phenol-terminated isocyanate is a terminal isocyanate polymer obtained by reacting polypropylene glycol with a weight average molecular weight of 1000-2000 with toluene diisocyanate.

6. The room temperature curing high temperature resistant two-component epoxy structural adhesive according to claim 1, characterized in that: The modified polyetheramine is an adduct obtained by mixing a bifunctional or trifunctional polyetheramine with a weight average molecular weight of 200 to 1000 and a bisphenol A epoxy resin in a mass ratio of 5:(1 to 3) to react.

7. The room temperature curing high temperature resistant two-component epoxy structural adhesive according to claim 1, characterized in that: The modified alicyclic amine is an adduct obtained by mixing alicyclic diamine and bisphenol A epoxy resin in a mass ratio of 5:(2-5).

8. The room temperature curing high temperature resistant two-component epoxy structural adhesive according to claim 1, characterized in that: The modified imidazole curing agent is prepared by reacting imidazole with monofunctional glycidyl ether; the mass ratio of the imidazole to the monofunctional glycidyl ether is (1.1-1.3):

1.

9. The room temperature curing high temperature resistant two-component epoxy structural adhesive according to claim 1, characterized in that: The room temperature curing high temperature resistant two-component epoxy structural adhesive also includes 0-20% filler, 0-5% thixotropic agent and 0-1% defoaming agent.

10. Use of the room temperature curing and high temperature resistant two-component epoxy structural adhesive according to any one of claims 1 to 9 in bonding a bottom plate of an FDM printer.

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