High-toughness modified epoxy resin material, method for preparing same, and use thereof

Abstract

The present application relates to the field of epoxy resin, in particular to a high toughness modified epoxy resin material and a preparation method and application thereof.The high toughness modified epoxy resin material comprises: liquid epoxy resin 50-100 parts by weight, curing agent 50-110 parts by weight, diluent 5-30 parts by weight, modified toughening agent 5-20 parts by weight and other auxiliary agent 1-10 parts by weight; wherein the modified toughening agent is core-shell particle modified with hydroxyl, carboxyl, amino or epoxy functional group.The modified epoxy resin material has high toughness and good comprehensive mechanical properties, the addition of the modified toughening agent can significantly improve the toughness of the modified epoxy resin material, and solves the problem of poor impact resistance of the epoxy resin; and the preparation method of the modified epoxy resin material is simple, and mass production can be realized.

Description

Technical Field

[0001] This invention relates to the field of epoxy resins, specifically to a high-toughness modified epoxy resin material, its preparation method, and its applications. Background Technology

[0002] Epoxy resin, due to its excellent adhesion, mechanical properties, and corrosion resistance, is often used as a matrix resin for composite materials and has been widely applied in aerospace, wind power, nuclear power, high-speed rail, and other fields. However, cured epoxy resin is brittle, has low impact resistance, poor resilience, and poor toughness, making it prone to cracking under external forces, which hinders its development in many high-tech fields.

[0003] CN109852003A discloses a method for preparing toughened epoxy resin, using core-shell structured silica / glycidyl polyacrylate nanoparticles as an additive, which are added to epoxy resin, followed by the addition of a curing agent. After curing, a toughened epoxy resin is formed. The amount of nanoparticles added in the prepared toughened epoxy resin accounts for 1‰ to 3‰ of the total mass of epoxy resin and curing agent, and the impact strength of the epoxy resin is increased by more than 50%, with a significant increase in toughness. However, the preparation process of this invention is relatively complex and time-consuming, which is not conducive to its widespread application and makes large-scale mass production difficult.

[0004] CN111087755A discloses a high-toughness resin matrix, its preparation method, application, and curing process. It mainly addresses the technical problem of poor toughness in existing epoxy resins. The method employs an epoxy resin matrix comprising, by weight, the following components: Component A: 50-100 parts of main epoxy resin; Component B: 20-120 parts of curing agent; Component C: 0.5-3 parts of directional reaction catalyst. The curing agent is a modified acid anhydride curing agent. This solution effectively solves the problem and can be used in the industrial production of products with high elongation and high fatigue resistance. However, the directional reaction catalyst used in this method has a high risk factor and low operability during the actual reaction process.

[0005] Therefore, it is very important to develop an epoxy resin with high toughness and a simple and safe preparation method to broaden its application fields. Summary of the Invention

[0006] The purpose of this invention is to overcome the problem of poor impact resistance of epoxy resins in existing technologies, and to provide a high-toughness modified epoxy resin material, its preparation method, and its applications. The modified epoxy resin material provided by this invention has good impact resistance, and the method is simple, easy to operate, and has low operating costs.

[0007] To achieve the above objectives, the first aspect of the present invention provides a high-toughness modified epoxy resin material, wherein the modified epoxy resin material comprises: 50-100 parts by weight of liquid epoxy resin, 50-110 parts by weight of curing agent, 5-30 parts by weight of diluent, 5-20 parts by weight of modified toughening agent and 1-10 parts by weight of other additives.

[0008] A second aspect of the present invention provides a method for preparing a high-toughness modified epoxy resin material, wherein the method includes:

[0009] (1) The liquid epoxy resin and the modified toughening agent are stirred and ultrasonically dispersed to obtain the first mixture;

[0010] (2) After mixing the curing agent, diluent, and other reagents with the first mixture, vacuum degassing is performed to obtain the second mixture;

[0011] (3) The second mixture is cured to obtain the high-toughness modified epoxy resin material.

[0012] The third aspect of this invention provides an application of the high-toughness modified epoxy resin material described in the first aspect or the high-toughness modified epoxy resin material prepared by the preparation method described in the second aspect in aerospace, rail transportation, wind power generation and bridge construction.

[0013] Through the above technical solution, the present invention can achieve the following technical effects:

[0014] (1) The modified epoxy resin material provided by the present invention uses nano-scale core-shell particle toughening agent, which can improve the toughness of the modified epoxy resin material without reducing the glass transition temperature; under the action of external load, the deformation of the particles and epoxy resin matrix is ​​not coordinated, resulting in particle interface adhesion and detachment, generating micro voids that dissipate a large amount of energy, thus playing a toughening role.

[0015] (2) The modified epoxy resin material provided by the present invention uses a modified toughening agent with hydroxyl, carboxyl, amino or epoxy groups on its surface, which can further improve the compatibility with the epoxy resin matrix and react with the functional groups in the epoxy resin matrix. When subjected to external impact, it can dissipate a large amount of energy.

[0016] (3) The modified epoxy resin material provided by the present invention, through the combined action of liquid epoxy resin, curing agent, diluent, modified toughening agent and other reagents, makes the viscosity (25℃) of the prepared modified epoxy resin material less than 1200cps, the pot life greater than 8h, meets the process conditions for use, and the preparation method is simple, easy to operate and low in cost, the process is environmentally friendly and safe, and can be used for industrial mass production. Detailed Implementation

[0017] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0018] The first aspect of the present invention provides a high-toughness modified epoxy resin material, wherein the modified epoxy resin material comprises: 50-100 parts by weight of liquid epoxy resin, 50-110 parts by weight of curing agent, 5-30 parts by weight of diluent, 5-20 parts by weight of modified toughening agent and 1-10 parts by weight of other additives.

[0019] The inventors of this invention discovered that under external load, the nanoscale core-shell particle toughening agent used in this invention causes uncoordinated deformation between the particles and the epoxy resin matrix, leading to particle interface adhesion and detachment, and the generation of microvoids that dissipate a large amount of energy. Since the surface of the modified toughening agent is modified with hydroxyl, carboxyl, amino, or epoxy groups, it can further improve the compatibility with the epoxy resin matrix and react with the functional groups in the epoxy resin matrix. When subjected to external impact, it can dissipate a large amount of energy, which is beneficial for toughening.

[0020] In some embodiments of the present invention, preferably, the liquid epoxy resin is selected from at least one of bisphenol A type glycidyl ether epoxy resin, bisphenol F type glycidyl ether epoxy resin, bisphenol S type glycidyl ether epoxy resin, bisphenol A type glycidylamine epoxy resin and bisphenol F type glycidylamine epoxy resin.

[0021] In some embodiments of the present invention, preferably, the core of the modified toughening agent is selected from at least one of butadiene, styrene, acrylate, urethane, methyl methacrylate and siloxane, and the shell is selected from any one of methyl methacrylate, acrylate and methacrylic acid.

[0022] In some embodiments of the present invention, preferably, the modified toughening agent is a core-shell particle with a shell modified with hydroxyl, carboxyl, amino, or epoxy functional groups; the particle size of the modified toughening agent is 100-200 nm, and the core diameter is 80-195 nm. According to the present invention, the modified toughening agent has good compatibility with liquid epoxy resin, and can effectively improve the toughness of the modified epoxy resin material when used, so that the modified epoxy resin material obtained after heat curing still has excellent toughness; in addition, by simultaneously controlling the particle size and core diameter of the modified toughening agent within the range defined by the present invention, the prepared modified epoxy resin material can have better impact resistance, tensile strength, elongation at break, flexural strength, and glass transition temperature.

[0023] In some embodiments of the present invention, preferably, the curing agent is selected from anhydride curing agents, and more preferably at least one of phthalic anhydride, trimellitic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, and nadic anhydride. In the present invention, the curing agent has good compatibility with liquid epoxy resin, enabling the epoxy resin to cure rapidly during use.

[0024] In some embodiments of the present invention, preferably, the diluent is selected from any one of n-butyl glycidyl ether, allyl glycidyl ether, 2-ethyl-hexyl glycidyl ether, phenyl glycidyl ether, polyethylene glycol diglycidyl ether, and polypropylene glycol diglycidyl ether. In the present invention, the diluent can effectively regulate the solubility and dispersibility of each component during the reaction process.

[0025] In some embodiments of the present invention, preferably, the other additives are selected from at least one of calcium carbonate, calcium silicate, kaolin, talc, nano-silica, and carbon black. In the present invention, the other additives can be coordinated with the components and fully dispersed in the epoxy resin matrix.

[0026] According to the present invention, the high-toughness modified epoxy resin material has a tensile strength ≥80MPa, an elongation at break ≥7%, and an impact strength ≥32kJ·m. -2 Glass transition temperature ≥120℃, viscosity <1200cps, pot life >8h.

[0027] A second aspect of the present invention provides a method for preparing a high-toughness modified epoxy resin material, wherein the method includes:

[0028] (1) The liquid epoxy resin and the modified toughening agent are stirred and ultrasonically dispersed to obtain the first mixture;

[0029] (2) After mixing the curing agent, diluent, and other reagents with the first mixture, vacuum degassing is performed to obtain the second mixture;

[0030] (3) The second mixture is cured to obtain the high-toughness modified epoxy resin material.

[0031] In this invention, the preparation method of the modified epoxy resin material is simple and easy to operate, and can be used for large-scale industrial production.

[0032] In some embodiments of the present invention, preferably, in step (1), the stirring speed is 300-400 rpm and the stirring time is 2-3 h. The present invention does not impose special restrictions on the conditions for ultrasonic dispersion; however, the ultrasonic dispersion time is preferably 0.5-1.5 h. The equipment used for stirring and ultrasonic dispersion is not particularly limited, as long as it can disperse the raw materials uniformly. In the present invention, sequentially subjecting the liquid epoxy resin and toughening agent to high-speed stirring and ultrasonic dispersion enables the toughening agent particles to be uniformly dispersed in the liquid epoxy resin matrix, which is beneficial for improving the toughness of the modified epoxy resin material.

[0033] In some embodiments of the present invention, preferably, in step (2), the mixing temperature is 25-50°C and the mixing time is 30-40 min. In the present invention, controlling the mixing conditions within the range defined by the present invention can ensure uniform mixing, and the modified epoxy resin material obtained by heat curing has excellent impact resistance; the degassing conditions are not particularly limited, as long as complete degassing can be achieved.

[0034] In some embodiments of the present invention, preferably, in step (3), the curing includes three stages: the first stage curing temperature is 50-70℃, and the curing time is 0.5-1h; the second stage curing temperature is 80-120℃, and the curing time is 1-3h; the third stage curing temperature is 120-160℃, and the curing time is 1-4h. In the present invention, controlling the thermosetting reaction time and temperature within the range defined by the present invention enables the thermosetting reaction to proceed more completely, which is beneficial to improving the toughness of the obtained modified epoxy resin material.

[0035] The third aspect of this invention provides an application of the high-toughness modified epoxy resin material described in the first aspect or the high-toughness modified epoxy resin material prepared by the preparation method described in the second aspect in aerospace, rail transportation, wind power generation and bridge construction.

[0036] The present invention does not impose any special restrictions on the source of the liquid epoxy resin, curing agent, diluent, toughening agent and other additives, which are generally commercially available.

[0037] The present invention will be described in detail below through embodiments.

[0038] The glass transition temperature (Tg) of the modified epoxy resin material was tested using differential scanning calorimetry (DSC) in accordance with the standard GB / T19466.2-2004.

[0039] The tensile and flexural properties of the modified epoxy resin materials were tested in accordance with GB / T 2567-2008 standard.

[0040] Impact performance of the modified epoxy resin material was tested according to GB / T 1043.1-2008 standard;

[0041] Viscosity was tested according to GB / T 22314-2008, the method for determining the viscosity of epoxy resins in plastics.

[0042] Example 1

[0043] (1) Bisphenol A type glycidyl ether epoxy resin and modified toughening agent (shell is acrylate, core is urethane, particle size is 125nm, core diameter is 109nm, and the modifying group is amino) are added at a mass ratio of 9:1, stirred at 400rpm for 2h, and then sonicated for 1h to obtain the first mixture after being fully dispersed.

[0044] (2) Weigh nadic anhydride, polypropylene glycol diglycidyl ether and calcium carbonate according to the mass ratio of the modified toughening agent, curing agent, diluent and other reagents of 10:110:10:3, and add them to the first mixture. Mix thoroughly for 40 minutes at a temperature of 40°C, and then degas under vacuum to obtain the second mixture.

[0045] (3) The second mixture is cured according to the following settings: the first stage curing temperature is 50°C and the curing time is 0.5h; the second stage curing temperature is 80°C and the curing time is 1h; and the third stage curing temperature is 130°C and the curing time is 2h. The temperature is increased by program to obtain the modified epoxy resin material.

[0046] The performance parameters of the modified epoxy resin materials obtained are shown in Table 1.

[0047] Example 2

[0048] (1) Bisphenol A type glycidylamine epoxy resin and modified toughening agent (shell is acrylate, core is urethane, particle size is 150nm, core diameter is 126nm, and modification group is carboxyl) are added at a mass ratio of 9:1, stirred at 400rpm for 2h, and then sonicated for 1h to obtain the first mixture after full dispersion.

[0049] (2) Weigh nadic anhydride, polyethylene glycol diglycidyl ether and kaolin in the mass ratio of the modified toughening agent, curing agent, diluent and other reagents of 10:110:10:3 and add them to the first mixture. Mix thoroughly for 40 minutes at a temperature of 40°C, and then degas under vacuum to obtain the second mixture.

[0050] (3) The second mixture is cured according to the following settings: the first stage curing temperature is 50°C and the curing time is 0.5h; the second stage curing temperature is 80°C and the curing time is 1h; and the third stage curing temperature is 130°C and the curing time is 2h. The temperature is increased by program to obtain the modified epoxy resin material.

[0051] The performance parameters of the modified epoxy resin materials obtained are shown in Table 1.

[0052] Example 3

[0053] (1) Bisphenol A type glycidylamine epoxy resin and modified toughening agent (shell is acrylate, core is siloxane, particle size is 175nm, core diameter is 143nm, and modified group is epoxy group) are added at a mass ratio of 9:1, stirred at 400rpm for 2h, and then sonicated for 1h to obtain the first mixture after full dispersion.

[0054] (2) Weigh nadic anhydride, polyethylene glycol diglycidyl ether and calcium silicate according to the mass ratio of the modified toughening agent, curing agent, diluent and other reagents of 10:110:10:3, and add them to the first mixture. Mix thoroughly for 40 minutes at a temperature of 40°C, and then degas under vacuum to obtain the second mixture.

[0055] (3) The second mixture is cured according to the following settings: the first stage curing temperature is 50°C and the curing time is 0.5h; the second stage curing temperature is 80°C and the curing time is 1h; and the third stage curing temperature is 130°C and the curing time is 2h. The temperature is increased by program to obtain the modified epoxy resin material.

[0056] The performance parameters of the modified epoxy resin materials obtained are shown in Table 1.

[0057] Example 4

[0058] (1) Bisphenol F type glycidyl ether epoxy resin and modified toughening agent (shell is methyl methacrylate, core is butadiene, particle size is 100nm, core diameter is 84nm, and the modifying group is epoxy group) are added at a mass ratio of 20:1, stirred at 400rpm for 2h, and then sonicated for 1h to obtain the first mixture after being fully dispersed.

[0059] (2) Methylhexahydrophthalic anhydride, allyl glycidyl ether and talc powder are weighed according to the mass ratio of the modified toughening agent, curing agent, diluent and other reagents of 5:90:8:5 and added to the first mixture. The mixture is thoroughly mixed for 40 minutes at a temperature of 40°C and then degassed under vacuum to obtain the second mixture.

[0060] (3) The second mixture is cured according to the following settings: the first stage curing temperature is 50°C and the curing time is 0.5h; the second stage curing temperature is 80°C and the curing time is 1h; and the third stage curing temperature is 130°C and the curing time is 2h. The temperature is increased by program to obtain the modified epoxy resin material.

[0061] The performance parameters of the modified epoxy resin materials obtained are shown in Table 1.

[0062] Example 5

[0063] (1) Bisphenol A type glycidyl ether epoxy resin and modified toughening agent (shell is methyl methacrylate, core is butadiene, particle size is 100nm, core diameter is 90nm, and the modifying group is epoxy group) are added at a mass ratio of 20:1, stirred at 400rpm for 2h, and then sonicated for 1h to obtain the first mixture after being fully dispersed.

[0064] (2) Methyltetrahydrophthalic anhydride, n-butyl glycidyl ether and nano silica were weighed according to the mass ratio of the modified toughening agent, curing agent, diluent and other reagents of 5:90:8:5 and added to the first mixture. The mixture was thoroughly mixed for 40 min at a temperature of 40°C and then degassed under vacuum to obtain the second mixture.

[0065] (3) The second mixture is cured by setting the curing temperature of 50°C for the first stage and the curing time of 0.5h, the curing temperature of 80°C for the second stage and the curing time of 1h, and the curing temperature of 130°C for the third stage and the curing time of 2h, and the temperature is increased by program to obtain the ring-modified epoxy resin material.

[0066] The performance parameters of the modified epoxy resin materials obtained are shown in Table 1.

[0067] Example 6

[0068] (1) Bisphenol A type glycidyl ether epoxy resin and modified toughening agent (shell is methacrylic acid, core is butadiene and styrene, particle size is 200nm, core diameter is 160nm, and the modifying group is hydroxyl) are added at a mass ratio of 20:1, stirred at 400rpm for 2h, and then sonicated for 1h to obtain the first mixture after being fully dispersed.

[0069] (2) Methyltetrahydrophthalic anhydride, n-butyl glycidyl ether and nano silica were weighed according to the mass ratio of the modified toughening agent, curing agent, diluent and other reagents of 5:90:8:5 and added to the first mixture. The mixture was thoroughly mixed for 40 min at a temperature of 40°C and then degassed under vacuum to obtain the second mixture.

[0070] (3) The second mixture is cured according to the following settings: the first stage curing temperature is 50°C and the curing time is 0.5h; the second stage curing temperature is 80°C and the curing time is 1h; and the third stage curing temperature is 130°C and the curing time is 2h. The temperature is increased by program to obtain the modified epoxy resin material.

[0071] The performance parameters of the modified epoxy resin materials obtained are shown in Table 1.

[0072] Comparative Example 1

[0073] (1) Bisphenol A type glycidyl ether epoxy resin, methyltetrahydrophthalic anhydride, n-butyl glycidyl ether and nano silica were fed in a mass ratio of 5:90:8:5 and mixed thoroughly for 40 min at a temperature of 40℃. Then the mixture was degassed under vacuum to obtain the mixture.

[0074] (2) The mixture is cured by setting the curing temperature of 50°C for the first stage and the curing time of 0.5h, the curing temperature of 80°C for the second stage and the curing time of 1h, and the curing temperature of 130°C for the third stage and the curing time of 2h, and the temperature is increased by program to obtain the modified epoxy resin material.

[0075] The performance parameters of the modified epoxy resin materials obtained are shown in Table 1.

[0076] Table 1 Performance Parameters

[0077]

[0078] As can be seen from the results in Table 1, the modified epoxy resin material prepared by the method of the present invention has high toughness and good comprehensive mechanical properties. From Examples 1-6 in Table 1, it can be seen that the modified epoxy resin material provided by the present invention has improved glass transition temperature, tensile strength, elongation at break, flexural strength, and impact strength; its viscosity is less than 1200 cps; and its pot life is greater than 8 hours, meeting the process conditions for use. Comparative Example 1, because it did not use the modified toughening agent specified in the present invention, has relatively poor comprehensive mechanical properties and toughness in its modified epoxy resin material.

[0079] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A high-toughness modified epoxy resin material, characterized in that, The modified epoxy resin material comprises: 50-100 parts by weight of liquid epoxy resin, 50-110 parts by weight of curing agent, 5-30 parts by weight of diluent, 5-20 parts by weight of modified toughening agent and 1-10 parts by weight of other additives. The modified toughening agent is a core-shell particle with a shell modified with carboxyl or amino functional groups; the core layer of the modified toughening agent is urethane, and the shell is acrylate. The modified toughening agent has a particle size of 100-200 nm and a core diameter of 80-195 nm; The curing agent is selected from at least one of phthalic anhydride, trimellitic anhydride and nadic anhydride; The other additives are selected from at least one of calcium carbonate, calcium silicate, kaolin, talc, nano silica, and carbon black.

2. The modified epoxy resin material according to claim 1, characterized in that, The liquid epoxy resin is selected from at least one of bisphenol A type glycidyl ether epoxy resin, bisphenol F type glycidyl ether epoxy resin, bisphenol S type glycidyl ether epoxy resin, bisphenol A type glycidylamine epoxy resin, and bisphenol F type glycidylamine epoxy resin.

3. The modified epoxy resin material according to claim 1, characterized in that, The diluent is selected from any one of n-butyl glycidyl ether, allyl glycidyl ether, 2-ethyl-hexyl glycidyl ether, phenyl glycidyl ether, polyethylene glycol diglycidyl ether, and polypropylene glycol diglycidyl ether.

4. A method for preparing a high-toughness modified epoxy resin material according to any one of claims 1-3, characterized in that, The method includes: (1) The liquid epoxy resin and the modified toughening agent are stirred and ultrasonically dispersed to obtain the first mixture; (2) After mixing the curing agent, diluent, and other reagents with the first mixture, vacuum degassing is performed to obtain the second mixture; (3) The second mixture is cured to obtain the high-toughness modified epoxy resin material.

5. The method according to claim 4, characterized in that, In step (1), the stirring speed is 300-400 rpm and the stirring time is 2-3 hours.

6. The method according to claim 4, characterized in that, In step (2), the mixing temperature is 25-50℃ and the mixing time is 30-40min.

7. The method according to claim 4, characterized in that, In step (3), the curing process includes three stages: the first stage has a curing temperature of 50-70℃ and a curing time of 0.5-1h; the second stage has a curing temperature of 80-120℃ and a curing time of 1-3h; and the third stage has a curing temperature of 120-160℃ and a curing time of 1-4h.

8. The application of a high-toughness modified epoxy resin material according to any one of claims 1-3 or a high-toughness modified epoxy resin material prepared by any one of claims 4-7 in aerospace, rail transportation, wind power generation and bridge construction.

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