High-toughness modified epoxy resin material as well as preparation method and application thereof

Abstract

The invention 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 the following components in parts by weight: 50-100 parts of liquid epoxy resin, 50-110 parts of a curing agent, 5-30 parts of a diluent, 5-20 parts of a modified toughening agent and 1-10 parts of other auxiliaries, wherein the modified toughening agent is a core-shell particle of which the shell is modified with hydroxyl, carboxyl, amino or epoxy functional groups. The modified epoxy resin material has high toughness and better comprehensive mechanical properties, the toughness of the modified epoxy resin material can be remarkably improved by adding the modified toughening agent, and the problem of poor impact resistance of epoxy resin is solved; the preparation method of the modified epoxy resin material is simple, and industrial mass production can be realized.

Description

Technical Field

[0001] The invention relates to the field of epoxy resins, and in particular to a high-toughness modified epoxy resin material and a preparation method and application thereof. Background Art

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

[0003] CN109852003A discloses a method for preparing a toughened epoxy resin, wherein core-shell structured silica / polyglycidyl acrylate nanoparticles are used as additives, added to epoxy resin, and then a curing agent is added to form a toughened epoxy resin after curing. The amount of nanoparticles added to the prepared toughened epoxy resin accounts for 1‰ to 3‰ of the total mass of the epoxy resin and the curing agent, and the impact strength of the epoxy resin is increased by more than 50%, and the toughness is significantly increased. However, the preparation process of the invention is relatively complicated and time-consuming, which is not conducive to promotion and application, and it is difficult to carry out large-scale mass production.

[0004] CN111087755A discloses a high-toughness resin matrix and its preparation method, application and curing process, which mainly solves the technical problem of poor toughness of epoxy resin in the prior art. By adopting an epoxy resin matrix, the following components are included by mass: 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; wherein the curing agent is a technical solution of modified anhydride curing agent, which solves the problem well and can be used in the industrial production of high elongation products and high fatigue resistance products. However, the directional reaction catalyst used in this method has a high risk factor and low operability in the actual reaction process.

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

[0006] The purpose of the present invention is to overcome the problem of poor impact resistance of epoxy resin in the prior art and provide a high-toughness modified epoxy resin material and its preparation method and application. The modified epoxy resin material provided by the present invention has good impact resistance, and the method is simple, easy to operate, and has low operating cost.

[0007] In order to achieve the above-mentioned purpose, 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 comprises:

[0009] (1) stirring and ultrasonically dispersing a liquid epoxy resin and a modified toughening agent to obtain a first mixture;

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

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

[0012] The third aspect of the present 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 adopts a 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 particles and the epoxy resin matrix deform uncoordinatedly, resulting in adhesion and detachment of the particle interface, generating micro-voids to dissipate a large amount of energy, thereby playing a toughening role.

[0015] (2) The modified epoxy resin material provided by the present invention uses a modified toughening agent whose surface is modified with hydroxyl, carboxyl, amino or epoxy groups, which can further improve the compatibility with the epoxy resin matrix and can 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 joint action of liquid epoxy resin, curing agent, diluent, modified toughening agent and other reagents, makes the viscosity (25°C) of the prepared modified epoxy resin material less than 1200cps and the applicable period greater than 8h, which meets the process conditions for use. 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 DESCRIPTION

[0017] The endpoints and any values ​​of the ranges disclosed in this article 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 each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[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 the present invention have discovered that, under the action of external loads, the nanoscale core-shell particle toughening agent used in the present invention causes uncoordinated deformation of the particles and the epoxy resin matrix, resulting in adhesion and detachment of the particle interface, and the generation of micro-voids that dissipate a large amount of energy; since the surface of the modified toughening agent is modified with hydroxyl, carboxyl, amino or epoxy groups, the compatibility with the epoxy resin matrix can be further improved, and it can 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 to toughening.

[0020] In some embodiments of the present invention, preferably, the liquid epoxy resin is selected from at least one of bisphenol A glycidyl ether epoxy resin, bisphenol F glycidyl ether epoxy resin, bisphenol S glycidyl ether epoxy resin, bisphenol A glycidyl amine epoxy resin and bisphenol F glycidyl amine 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 a hydroxyl, carboxyl, amino or epoxy functional group; the particle size of the modified toughening agent is 100-200nm, and the core diameter is 80-195nm. 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 heating and curing still has excellent toughness; in addition, the particle size of the modified toughening agent and the core diameter of the modified toughening agent are simultaneously controlled within the range specified by the present invention, so that the prepared modified epoxy resin material has 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, 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 the liquid epoxy resin, and can make the epoxy resin cure quickly 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 adjust the solubility and dispersibility of each component during the reaction.

[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 silicon dioxide and carbon black. In the present invention, the other additives can be matched with each component and fully dispersed in the epoxy resin matrix.

[0026] According to the present invention, the tensile strength of the high-toughness modified epoxy resin material is ≥80MPa, the elongation at break is ≥7%, and the impact strength is ≥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 comprises:

[0028] (1) stirring and ultrasonically dispersing a liquid epoxy resin and a modified toughening agent to obtain a first mixture;

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

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

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

[0032] In some embodiments of the present invention, preferably, in step (1), the stirring speed is 300-400rpm and the stirring time is 2-3h. In the present invention, there is no special restriction on the conditions of the ultrasonic dispersion. In the present invention, the time of the ultrasonic dispersion is preferably 0.5-1.5h; there is no special restriction on the equipment for the stirring and ultrasonic dispersion, as long as the raw materials can be evenly dispersed. In the present invention, the liquid epoxy resin and the toughening agent are sequentially subjected to high-speed stirring and ultrasonic dispersion, so that the toughening agent particles can be evenly dispersed in the liquid epoxy resin matrix, which is beneficial to 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 minutes. In the present invention, the mixing conditions are controlled within the range defined in the present invention to ensure uniform mixing, and the modified epoxy resin material obtained by heating and 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 curing temperature of the first stage is 50-70°C, and the curing time is 0.5-1h; the curing temperature of the second stage is 80-120°C, and the curing time is 1-3h; the curing temperature of the third stage is 120-160°C, and the curing time is 1-4h. In the present invention, controlling the heat curing reaction time and temperature within the range defined in the present invention can make the heat curing reaction more complete, which is beneficial to improving the toughness of the obtained modified epoxy resin material.

[0035] The third aspect of the present 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 has no special restrictions on the sources of the liquid epoxy resin, curing agent, diluent, toughening agent and other additives, and they can generally be commercially available.

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

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

[0039] The tensile properties and bending properties of the modified epoxy resin material were tested according to GB / T 2567-2008 standard;

[0040] The impact performance is tested on the modified epoxy resin material with reference to GB / T 1043.1-2008 standard;

[0041] The viscosity is tested according to GB / T 22314-2008, the method for determining the viscosity of plastic epoxy resin.

[0042] Example 1

[0043] (1) adding bisphenol A glycidyl ether epoxy resin and modified toughening agent (shell is acrylate, core is urethane, particle size is 125 nm, core diameter is 109 nm, and modified group is amino group) at a mass ratio of 9:1, stirring at 400 rpm for 2 h, and then ultrasonicating for 1 h to obtain a first mixture after being fully dispersed;

[0044] (2) weighing 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, adding them to the first mixture, mixing them thoroughly at a temperature of 40° C. for 40 minutes, and then vacuum degassing to obtain a second mixture;

[0045] (3) Curing the second mixture by programmed temperature increase according to the following settings: first stage curing temperature of 50° C., curing time of 0.5 h, second stage curing temperature of 80° C., curing time of 1 h, and third stage curing temperature of 130° C., curing time of 2 h, to obtain a modified epoxy resin material.

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

[0047] Example 2

[0048] (1) adding bisphenol A glycidylamine epoxy resin and modified toughening agent (shell is acrylate, core is urethane, particle size is 150 nm, core diameter is 126 nm, and modified group is carboxyl) in a mass ratio of 9:1, stirring at 400 rpm for 2 h, and then ultrasonicating for 1 h to obtain a first mixture after being fully dispersed;

[0049] (2) weighing nadic anhydride, polyethylene glycol diglycidyl ether and kaolin according to the mass ratio of the modified toughening agent, curing agent, diluent and other reagents being 10:110:10:3, adding the mixture to the first mixture, mixing the mixture thoroughly at 40° C. for 40 minutes, and then vacuum degassing the mixture to obtain a second mixture;

[0050] (3) Curing the second mixture by programmed temperature increase according to the following settings: first stage curing temperature of 50° C., curing time of 0.5 h, second stage curing temperature of 80° C., curing time of 1 h, and third stage curing temperature of 130° C., curing time of 2 h, to obtain a modified epoxy resin material.

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

[0052] Example 3

[0053] (1) adding bisphenol A glycidylamine epoxy resin and modified toughening agent (shell is acrylate, core is siloxane, particle size is 175 nm, core diameter is 143 nm, and modified group is epoxy group) in a mass ratio of 9:1, stirring at 400 rpm for 2 h, and then ultrasonicating for 1 h to obtain a first mixture after being fully dispersed;

[0054] (2) weighing 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 being 10:110:10:3, adding the mixture to the first mixture, mixing the mixture thoroughly at a temperature of 40° C. for 40 minutes, and then vacuum degassing the mixture to obtain a second mixture;

[0055] (3) Curing the second mixture by programmed temperature increase according to the following settings: first stage curing temperature of 50° C., curing time of 0.5 h, second stage curing temperature of 80° C., curing time of 1 h, and third stage curing temperature of 130° C., curing time of 2 h, to obtain a modified epoxy resin material.

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

[0057] Example 4

[0058] (1) adding bisphenol F glycidyl ether epoxy resin and modified toughening agent (shell is methyl methacrylate, core is butadiene, particle size is 100 nm, core diameter is 84 nm, and modified group is epoxy group) at a mass ratio of 20:1, stirring at 400 rpm for 2 h, and then ultrasonicating for 1 h to obtain a first mixture after being fully dispersed;

[0059] (2) weighing methyl hexahydrophthalic anhydride, allyl glycidyl ether and talc according to the mass ratio of the modified toughening agent, curing agent, diluent and other reagents of 5:90:8:5, adding them to the first mixture, fully mixing at a temperature of 40° C. for 40 minutes, and then vacuum degassing to obtain a second mixture;

[0060] (3) Curing the second mixture by programmed temperature increase according to the following settings: first stage curing temperature of 50° C., curing time of 0.5 h, second stage curing temperature of 80° C., curing time of 1 h, and third stage curing temperature of 130° C., curing time of 2 h, to obtain a modified epoxy resin material.

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

[0062] Example 5

[0063] (1) adding bisphenol A glycidyl ether epoxy resin and modified toughening agent (shell is methyl methacrylate, core is butadiene, particle size is 100 nm, core diameter is 90 nm, and modified group is epoxy group) at a mass ratio of 20:1, stirring at 400 rpm for 2 h, and then ultrasonicating for 1 h to obtain a first mixture after being fully dispersed;

[0064] (2) weighing methyltetrahydrophthalic anhydride, n-butyl glycidyl ether and nano-silicon dioxide according to the mass ratio of the modified toughening agent, curing agent, diluent and other reagents of 5:90:8:5, adding them to the first mixture, mixing them thoroughly at a temperature of 40° C. for 40 minutes, and then vacuum degassing to obtain a second mixture;

[0065] (3) Curing the second mixture by programmed temperature increase according to the following settings: first stage curing temperature of 50° C., curing time of 0.5 h, second stage curing temperature of 80° C., curing time of 1 h, and third stage curing temperature of 130° C., curing time of 2 h, to obtain a ring-modified epoxy resin material.

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

[0067] Example 6

[0068] (1) adding bisphenol A glycidyl ether epoxy resin and modified toughening agent (shell is methacrylic acid, core is butadiene and styrene, particle size is 200 nm, core diameter is 160 nm, and modified group is hydroxyl group) at a mass ratio of 20:1, stirring at 400 rpm for 2 h, and then ultrasonicating for 1 h to obtain a first mixture after being fully dispersed;

[0069] (2) weighing methyltetrahydrophthalic anhydride, n-butyl glycidyl ether and nano-silicon dioxide according to the mass ratio of the modified toughening agent, curing agent, diluent and other reagents of 5:90:8:5, adding them to the first mixture, mixing them thoroughly at a temperature of 40° C. for 40 minutes, and then vacuum degassing to obtain a second mixture;

[0070] (3) Curing the second mixture by programmed temperature increase according to the following settings: first stage curing temperature of 50° C., curing time of 0.5 h, second stage curing temperature of 80° C., curing time of 1 h, and third stage curing temperature of 130° C., curing time of 2 h, to obtain a modified epoxy resin material.

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

[0072] Comparative Example 1

[0073] (1) adding bisphenol A glycidyl ether epoxy resin, methyltetrahydrophthalic anhydride, n-butyl glycidyl ether and nano-silicon dioxide in a mass ratio of 5:90:8:5, fully mixing at a temperature of 40° C. for 40 minutes, and then vacuum degassing to obtain a mixture;

[0074] (2) Curing the mixture by programmed temperature increase according to the following settings: the first stage curing temperature is 50° C., the curing time is 0.5 h, the second stage curing temperature is 80° C., the curing time is 1 h, and the third stage curing temperature is 130° C., the curing time is 2 h, to obtain a modified epoxy resin material.

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

[0076] Table 1 Performance parameters

[0077]

[0078] It can be seen from the results in Table 1 that the modified epoxy resin material prepared by the method of the present invention has high toughness and good comprehensive mechanical properties. It can be seen from Examples 1-6 in Table 1 that the glass transition temperature, tensile strength, elongation at break, and impact strength of the modified epoxy resin material provided by the present invention are improved, the viscosity is less than 1200cps, and the applicable period is greater than 8h, which meets the process conditions for use; since Comparative Example 1 does not use the modified toughening agent defined by the present invention, the comprehensive mechanical properties and toughness of the modified epoxy resin material prepared in Comparative Example 1 are relatively poor.

[0079] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to 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 auxiliary agents.

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 glycidyl ether epoxy resin, bisphenol F glycidyl ether epoxy resin, bisphenol S glycidyl ether epoxy resin, bisphenol A glycidyl amine epoxy resin and bisphenol F glycidyl amine epoxy resin.

3. The modified epoxy resin material according to claim 1 or 2, characterized in that: The core layer 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.

4. The modified epoxy resin material according to any one of claims 1 to 3, characterized in that: The modified toughening agent is a core-shell particle with a shell modified with a hydroxyl, carboxyl, amino or epoxy functional group; Preferably, the modified toughening agent has a particle size of 100-200 nm and a core diameter of 80-195 nm.

5. The modified epoxy resin material according to any one of claims 1 to 4, characterized in that: The curing agent is selected from anhydride curing agents, preferably at least one of phthalic anhydride, trimellitic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride and nadic anhydride.

6. The modified epoxy resin material according to any one of claims 1 to 5, 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.

7. The modified epoxy resin material according to any one of claims 1 to 6, characterized in that: The other auxiliary agents are selected from at least one of calcium carbonate, calcium silicate, kaolin, talc, nano silicon dioxide and carbon black.

8. A method for preparing a high-toughness modified epoxy resin material, characterized in that: The method includes: (1) stirring and ultrasonically dispersing a liquid epoxy resin and a modified toughening agent to obtain a first mixture; (2) mixing a curing agent, a diluent, and other reagents with the first mixture, and then performing vacuum degassing to obtain a second mixture; (3) Curing the second mixture to obtain the high-toughness modified epoxy resin material.

9. The method according to claim 8, characterized in that In step (1), the stirring speed is 300-400 rpm and the stirring time is 2-3 h; Preferably, in step (2), the mixing temperature is 25-50°C and the mixing time is 30-40min; Preferably, in step (3), the curing includes three stages, the curing temperature of the first stage is 50-70°C, and the curing time is 0.5-1h; the curing temperature of the second stage is 80-120°C, and the curing time is 1-3h; the curing temperature of the third stage is 120-160°C, and the curing time is 1-4h.

10. A high-toughness modified epoxy resin material as described in any one of claims 1 to 7 or a high-toughness modified epoxy resin material prepared by the preparation method as described in claim 8 or 9, or use thereof in aerospace, rail transportation, wind power generation and bridge construction.

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