Flame-retardant and easily degradable epoxy resin precursor, cured product, preparation method and application

Abstract

The present invention discloses a flame retardant and easily degradable epoxy resin precursor, a cured product, a preparation method and an application. The flame retardant and easily degradable epoxy resin precursor comprises the following components calculated by weight: 40 to 50 parts of epoxy resin monomer, 25 to 30 parts of curing agent, 10 to 15 parts of phytate, and 1 to 5 parts of auxiliary agent, wherein the curing agent comprises an acid curing agent and / or an acid anhydride curing agent. The present invention uses a polyester cross-linked network as a degradable main body, adds phytate as a reactive flame retardant, a curing accelerator, and an ester exchange catalyst, and the obtained epoxy resin cured product has excellent reactivity, flame retardancy, easy degradability, thermal stability and mechanical properties. In addition, due to the ester exchange catalytic effect of the ionic salt group, the cured product can be easily degraded in the presence of alcohol and amine, or reshaped under hot pressing / no catalytic conditions, and can be used as an environmentally friendly and safe epoxy resin matrix in the fields of coatings, adhesive potting, composite materials, etc.

Description

Technical Field

[0001] The present invention belongs to the technical field of flame-retardant epoxy resin materials, and relates to an epoxy resin precursor, and specifically to a flame-retardant and easily degradable epoxy resin precursor, a corresponding epoxy resin cured product and a preparation method thereof, as well as a degradation and reshaping method and application thereof. Background Art

[0002] Epoxy resin is an important thermosetting resin with excellent mechanical properties, chemical resistance, dimensional stability, thermal stability, bonding properties, insulation, etc. It is widely used in various fields including electronics, automobiles, construction, etc. However, traditional epoxy resins usually have high flammability and cannot meet the application occasions with high requirements for flame retardancy, especially aerospace, rail transportation, etc. At the same time, epoxy resin will form a three-dimensional cross-linked network after curing, which has the characteristics of infusibility and insolubility. Once the material is damaged, it is difficult to degrade or recycle, resulting in a large amount of solid waste, and causing waste of resources and environmental pollution. Therefore, it is of great significance to give epoxy resin flame retardancy and degradability.

[0003] In response to the above problems, the currently commonly used method is to use a matrix containing dynamic covalent bonds in combination with an additive flame retardant. For example, the published patent CN1 12029239A reports a degradable flame-retardant epoxy SMC resin composition, whose degradability is mainly imparted by the acetal bond in the amine curing agent, and the flame retardancy is mainly achieved by adding an additive flame retardant. Patent CN112029233A reports a degradable low-density flame-retardant epoxy SMC resin composition, whose degradability is mainly imparted by the Schiff base bond in the amine curing agent, and the flame retardancy is mainly achieved by adding an additive flame retardant. However, on the one hand, most of the dynamic covalent bonds are not located in the cross-linking points, resulting in degradation products mainly being polymer fragments with low utilization value. On the other hand, additive flame retardants inevitably have compatibility and easy migration problems during use, and the use of reactive flame retardants will lead to the formation of more non-degradable chemical bonds in the cross-linking network, thereby greatly reducing the degradation efficiency of the material. Therefore, it is extremely challenging to achieve both efficient flame retardancy and efficient degradation. Summary of the invention

[0004] The main purpose of the present invention is to provide a flame retardant and easily degradable epoxy resin precursor to overcome the deficiencies of the prior art.

[0005] Another object of the present invention is to provide a corresponding epoxy resin cured product and a preparation method thereof.

[0006] Another object of the present invention is to provide a degradation method, a remodeling method and an application of the epoxy resin cured product.

[0007] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention includes:

[0008] An embodiment of the present invention provides a flame retardant and easily degradable epoxy resin precursor, which includes the following components calculated in parts by weight: 40 to 50 parts of epoxy resin monomer, 25 to 30 parts of curing agent, 10 to 15 parts of phytate, and 1 to 5 parts of auxiliary agent, wherein the curing agent includes an acid curing agent and / or an acid anhydride curing agent.

[0009] The embodiment of the present invention further provides a cured epoxy resin, which is formed by curing the aforementioned flame-retardant and easily degradable epoxy resin precursor.

[0010] Furthermore, the epoxy resin cured product has the following general formula:

[0011]

[0012] Among them, R 1 , R 2 Corresponding to the main structure of epoxy resin monomer and the main structure of curing agent, R 3 The main structure of the corresponding active diluent, or R 3 With R 2 Same, R 4 It is a phosphate ion pair or an ion pair with glycidyl phosphate;

[0013] Specifically, R 4 The structure can be

[0014] An embodiment of the present invention also provides a method for preparing an epoxy resin cured product, which comprises: heating the aforementioned flame retardant and easily degradable epoxy resin precursor to 55-80°C and curing it for 1-10 hours, then curing it at 80-100°C for 1-5 hours, and finally curing it at 100-130°C for 1-10 hours to obtain an epoxy resin cured product.

[0015] The embodiment of the present invention further provides a degradation method of epoxy resin cured material, which comprises: mixing the epoxy resin cured material with a solvent in the presence of amine and / or alcohol to achieve aminolysis or alcoholysis.

[0016] An embodiment of the present invention further provides a method for reshaping an epoxy resin cured product, which comprises: reshaping the epoxy resin cured product under hot pressing / no catalysis conditions.

[0017] The embodiment of the present invention also provides the application of the aforementioned epoxy resin cured product as an environmentally friendly and safe epoxy resin matrix in the fields of coatings, adhesive potting or composite materials.

[0018] Compared with the prior art, the advantages of the present invention include at least:

[0019] The present invention uses a cross-linked network of a polyol as a degradable main body, adds phytate as a reactive flame retardant, a curing accelerator, and an ester exchange catalyst, and the resulting epoxy resin cured product has excellent reactivity, flame retardancy, easy degradability, thermal stability, and mechanical properties. In addition, due to the ester exchange catalytic effect of the ionic salt group, the cured product can be easily degraded in the presence of alcohols and amines, or reshaped under hot pressing / no catalytic conditions, and can be used as an environmentally friendly and safe epoxy resin matrix in the fields of coatings, adhesive potting, composite materials, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 is a gel temperature curve of the epoxy resin precursor prepared in Example 1 of the present invention;

[0022] Figure 2 It is the infrared spectrum of the epoxy resin cured product prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0023] As mentioned above, in view of the defects of the prior art, the inventor of this case has proposed the technical solution of the present invention after long-term research and extensive practice. The following specific implementation will provide a more complete understanding of the present invention, and detailed embodiments of the present invention are disclosed herein; however, it should be understood that the disclosed embodiments are only exemplary of the present invention, and the present invention can be embodied in various forms. Therefore, the specific functional details disclosed herein should not be interpreted as being restrictive, but only as the basis of the claims and as a representative basis for teaching technicians in the relevant field to adopt the present invention in different ways in any appropriate detailed embodiment.

[0024] The technical solution, its implementation process and principle will be further explained as follows.

[0025] One aspect of an embodiment of the present invention provides a flame retardant and easily degradable epoxy resin precursor including the following components calculated by weight: 40 to 50 parts of epoxy resin monomer, 25 to 30 parts of curing agent (acid curing agent and / or anhydride curing agent), 10 to 15 parts of phytate, and 1 to 5 parts of other additives.

[0026] In some embodiments, the epoxy resin monomer includes any one or a combination of two or more of bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, 4,4′-dihydroxydiphenyl sulfide epoxy resin, 4,4′-dihydroxybenzophenone epoxy resin, hydrogenated bisphenol epoxy resin, etc., but is not limited thereto.

[0027] In some embodiments, the curing agent (acid curing agent and / or anhydride curing agent) includes any one or a combination of two or more of adipic acid, malonic acid, succinic acid, a long-chain dicarboxylic acid having a carbon number greater than 4, an alicyclic anhydride, terephthalic acid, phthalic acid, isophthalic acid, itaconic acid, fumaric acid, maleic acid, succinic acid, malic acid, tartaric acid, citric acid, aliphatic anhydrides, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, pyromellitic dianhydride, high phthalic anhydride, biphenyl anhydride, phenylmaleic anhydride, phthalic anhydride, phenylmaleic anhydride, 1,8-naphthalene dicarboxylic anhydride, 1,2-naphthalene dicarboxylic anhydride, 2,3-pyrazine dicarboxylic anhydride, 3-hydroxyphthalic anhydride, 2,3-naphthalene dicarboxylic anhydride, 2,3-pyridine dicarboxylic anhydride and other modified anhydrides, but is not limited thereto.

[0028] In some embodiments, the phytate includes any one or a combination of two or more of calcium phytate, potassium phytate, sodium phytate, zinc phytate, etc., but is not limited thereto.

[0029] Furthermore, the auxiliary agent includes any one or a combination of two or more of active diluents, curing accelerators, antioxidants, anti-aging agents, thixotropic agents, defoaming agents, dispersants, colorants, etc., but is not limited thereto.

[0030] Another aspect of the embodiments of the present invention further provides an epoxy resin cured product, which is prepared from the aforementioned flame-retardant and easily degradable epoxy resin precursor by mixing and curing.

[0031] Furthermore, the epoxy resin cured product has the following general formula:

[0032]

[0033] Among them, R 1 , R 2 Corresponding to the main structure of epoxy resin monomer and the main structure of curing agent, R 3 The main structure corresponding to the active diluent (if any). If the auxiliary does not contain active diluent, then R 3 Equal to R 2 , R 4 It is a phosphate ion pair or an ion pair with glycidyl phosphate.

[0034] Furthermore, R 4 The structure is Wherein, M includes any one or a combination of two or more metal cations such as calcium, potassium, sodium, zinc, etc., and the value of n corresponds to the valence state of M.

[0035] The present invention uses a cross-linked network of a polyol as a degradable main body, adds phytate as a reactive flame retardant, a curing accelerator, and an ester exchange catalyst, and the flame retardant grade of the epoxy resin cured product obtained reaches UL-94V-0, the limiting oxygen index is higher than 35%, and it has excellent reactivity, flame retardancy, easy degradability, thermal stability and mechanical properties, and the degradation products are mostly high-value products such as dibasic acids and glycerol ethers. In addition, due to the ester exchange catalysis of the ionic salt group, the cured product can be easily degraded in the presence of alcohols and amines, or reshaped under hot pressing / no catalysis conditions.

[0036] Furthermore, the gel temperature of the flame-retardant and easily degradable epoxy resin precursor is 100-130°C.

[0037] Furthermore, the epoxy resin cured product has a glass transition temperature of 90 to 120°C, a tensile strength of 60 to 80 MPa, and an impact strength of 10 to 14 kJ / m 2 .

[0038] Another aspect of an embodiment of the present invention also provides a method for preparing an epoxy resin cured product, which comprises: heating the aforementioned flame retardant and easily degradable epoxy resin precursor to 55-80°C and curing it for 1-10 hours, then curing it at 80-100°C for 1-5 hours, and finally curing it at 100-130°C for 1-10 hours to obtain an epoxy resin cured product.

[0039] Another aspect of an embodiment of the present invention also provides a method for degrading an epoxy resin cured material, comprising: mixing the epoxy resin cured material with a solvent in the presence of an amine and / or an alcohol to achieve aminolysis or alcoholysis, wherein the aminolysis or alcoholysis is carried out in an environment of 0 to 200°C.

[0040] Furthermore, the epoxy resin cured product can be degraded under mild conditions, and the degradation method is any one or a combination of aminolysis and alcoholysis under solvent conditions, and the treatment is carried out under heating / normal temperature environment for 1 to 120 hours.

[0041] Furthermore, the alcohol includes any one or a combination of two of monoalcohols, diols and polyols containing C1 to C20, for example, preferably any one or a combination of two of ethylene glycol, glycerol, tert-butyl alcohol, etc., but not limited thereto.

[0042] Furthermore, the amine includes any one or a combination of two of monoamines, diamines and polyamines containing C1 to C20, for example, any one or a combination of two of ethylenediamine, propylenediamine, diethylenetriamine, etc., but not limited thereto.

[0043] Furthermore, the solvent includes any one or a combination of two or more of acetone, butanone, ethyl acetate, propyl acetate, butyl acetate, dichloromethane, chloroform, ether, tetrahydrofuran, dioxane, dimethyl sulfoxide, acetonitrile, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, etc., but is not limited thereto.

[0044] Another aspect of an embodiment of the present invention provides a method for reshaping an epoxy resin cured product, comprising: reshaping the epoxy resin cured product under hot pressing / catalytically insulated conditions, wherein the reshaping conditions include but are not limited to: a temperature of 100 to 200°C, a pressure of 1 to 30 MPa, and a reshaping treatment time of 0.1 to 12 hours.

[0045] Another aspect of the embodiments of the present invention further provides applications of the aforementioned epoxy resin cured product, for example, it can be used as an environmentally friendly and safe epoxy resin matrix in the fields of coatings, adhesive potting, composite materials, etc.

[0046] Hereinafter, the technical scheme of the present invention will be further described through the following specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments, and do not limit the scope of the present invention. It should be pointed out that the embodiments described below are intended to facilitate the understanding of the present invention, and do not have any limiting effect on it. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present invention.

[0047] The raw materials used in the embodiments of the present invention are all purchased from the market.

[0048] The instruments and equipment used in the examples are all conventional equipment in the relevant fields, and the performance tests are all in accordance with the requirements of conventional standards.

[0049] Example 1

[0050] Weigh 45 parts of bisphenol A epoxy resin monomer, 27 parts of methyltetrahydrophthalic anhydride curing agent, 12 parts of phytic acid calcium salt, 2 parts of active diluent (brand 678), 1 part of antioxidant, 0.5 parts of colorant, and 0.5 parts of defoamer. Stir and mix thoroughly and then cure. The gel temperature of the mixture is 114°C. The rheological results are as follows: Figure 1 As shown, the curing procedure is: 60℃ / 6 hours, 85℃ / 2 hours, 110℃ / 6 hours, and the epoxy resin cured product is obtained. The infrared spectrum of the cured product is shown in Figure 2 shown.

[0051] The obtained epoxy resin cured product has a UL-94 grade of V-0, a limiting oxygen index of 36.2%, a glass transition temperature of 92°C, a tensile strength of 63MPa, and an impact strength of 12.2kJ / m 2 The epoxy resin cured product can be reshaped after being treated at a temperature of 150°C and a pressure of 12 MPa for 3 hours, and can be completely degraded after being heated at 80°C for 4 hours in an ethylene glycol / DMF solution.

[0052] Example 2

[0053] Weigh 50 parts of bisphenol S epoxy resin monomer, 30 parts of biphenyl anhydride curing agent, 15 parts of potassium phytate, 1 part of antioxidant, 1 part of thixotropic agent, and 0.5 parts of defoaming agent. Stir and mix thoroughly and then cure. The gel temperature of the mixture is 124°C. The curing procedure is: 65°C / 7 hours, 90°C / 1.5 hours, 115°C / 7 hours to obtain epoxy resin cured product.

[0054] The obtained epoxy resin cured product has a UL-94 grade of V-0, a limiting oxygen index of 40.4%, a glass transition temperature of 102°C, a tensile strength of 74MPa, and an impact strength of 13.1kJ / m 2 The epoxy resin cured product can be reshaped after being treated at 180°C and 15 MPa for 1 hour, and can be completely degraded after being heated at 100°C for 3 hours in ethylenediamine / DMSO solution.

[0055] Example 3

[0056] Weigh 40 parts of bisphenol F epoxy resin monomer, 25 parts of methyl nadic anhydride curing agent, 10 parts of phytic acid sodium salt, 1 part of curing accelerator, 0.5 parts of thixotropic agent, and 0.5 parts of defoaming agent. Stir and mix thoroughly and then cure. The gel temperature of the mixture is 101°C. The curing procedure is: 55°C / 4 hours, 80°C / 1 hour, and 100°C / 1 hour to obtain epoxy resin cured product.

[0057] The obtained epoxy resin cured product has a UL-94 grade of V-0, a limiting oxygen index of 35.4%, a glass transition temperature of 90°C, a tensile strength of 58MPa, and an impact strength of 11.4kJ / m 2 The epoxy resin cured product can be reshaped after being treated at 100°C and 1 MPa for 12 hours, and can be completely degraded after being heated at 65°C in a glycerol / NMP solution for 6 hours.

[0058] Example 4

[0059] Weigh 48 parts of hydrogenated bisphenol A epoxy resin monomer, 10 parts of adipic acid curing agent, 16 parts of phthalic anhydride curing agent, 13 parts of phytic acid zinc salt, 2 parts of active diluent (brand 692), 1 part of antioxidant, 1 part of anti-aging agent, 0.5 parts of dispersant, and 0.5 parts of defoamer. Stir and mix thoroughly and then cure. The gel temperature of the mixture is 117°C. The curing procedure is: 80°C / 5 hours, 100°C / 1.5 hours, 125°C / 5 hours to obtain epoxy resin cured product.

[0060] The obtained epoxy resin cured product has a UL-94 grade of V-0, a limiting oxygen index of 36.8%, a glass transition temperature of 95°C, a tensile strength of 66MPa, and an impact strength of 11.2kJ / m 2 The epoxy resin cured product can be reshaped after being treated at a temperature of 200°C and a pressure of 1 MPa for 2 hours, and can be completely degraded after being heated at 90°C for 6 hours in a propylene diamine / ethyl acetate solution.

[0061] Example 5

[0062] Weigh 40 parts of 4,4′-dihydroxydiphenyl sulfide epoxy resin monomer, 25 parts of pyromellitic anhydride curing agent, 12 parts of phytic acid zinc salt, 1 part of curing accelerator (DMP-30), 0.5 parts of thixotropic agent, and 0.5 parts of defoaming agent. Stir and mix thoroughly and then cure. The mixture gel temperature is 107°C. The curing procedure is: 80°C / 1 hour, 100°C / 1 hour, and 130°C / 1 hour to obtain epoxy resin cured product.

[0063] The obtained epoxy resin cured product has a UL-94 grade of V-0, a limiting oxygen index of 39.4%, a glass transition temperature of 104°C, a tensile strength of 71MPa, and an impact strength of 11.7kJ / m 2 The epoxy resin cured product can be reshaped after being treated at a temperature of 200°C and a pressure of 30 MPa for 0.1 hour, and can be completely degraded after being placed in a tert-butyl alcohol / dioxane solution at room temperature for 120 hours.

[0064] Example 6

[0065] Weigh 42 parts of 4,4′-dihydroxybenzophenone epoxy resin monomer, 28 parts of biphenyl anhydride curing agent, 14 parts of potassium phytate, 0.5 parts of antioxidant, 0.3 parts of anti-aging agent, and 0.5 parts of defoaming agent. Stir and mix thoroughly and then cure. The gel temperature of the mixture is 122°C. The curing procedure is: 55°C / 10 hours, 80°C / 5 hours, and 130°C / 10 hours to obtain an epoxy resin cured product.

[0066] The obtained epoxy resin cured product has a UL-94 grade of V-0, a limiting oxygen index of 41.2%, a glass transition temperature of 112°C, a tensile strength of 78MPa, and an impact strength of 10.9kJ / m 2 The epoxy resin cured product can be reshaped after being treated at a temperature of 160°C and a pressure of 20 MPa for 4 hours, and can be completely degraded after being heated at 200°C for 1 hour in a diethylenetriamine / chloroform solution.

[0067] Comparative Example 1

[0068] The difference between this comparative example and Example 1 is that 12 parts of phytate in Example 1 are replaced by 4 parts of methyltetrahydrophthalic anhydride curing agent and 8 parts of ammonium polyphosphate flame retardant, and other components and operations remain unchanged.

[0069] The gel temperature of the obtained mixture is 146°C, the UL-94 grade of the obtained epoxy resin cured product is V-0, the limiting oxygen index is 33.2%, the glass transition temperature is 94°C, the tensile strength is 61MPa, and the impact strength is 11.8kJ / m 2 The epoxy resin cured product showed no significant changes after being treated at 150°C and 12 MPa for 3 hours, or heated at 80°C for 120 hours in ethylene glycol / DMF solution.

[0070] Comparative Example 2

[0071] The difference between this comparative example and Example 2 is that 15 parts of phytate in Example 2 are replaced by 5 parts of biphenyl anhydride curing agent and 10 parts of phosphorus-nitrogen combination flame retardant, and other components and operations remain unchanged.

[0072] The obtained mixture has a gel temperature of 153°C, and the obtained epoxy resin cured product has a UL-94 grade of V-0, a limiting oxygen index of 32.4%, a glass transition temperature of 103°C, a tensile strength of 72MPa, and an impact strength of 12.4kJ / m 2 There was no significant change in the epoxy resin cured product after being treated at 180°C and 15 MPa for 1 hour, or after being heated at 100°C for 120 hours in ethylenediamine / DMSO solution.

[0073] Comparative Example 3

[0074] The difference between this comparative example and Example 3 is that 10 parts of phytate in Example 3 are replaced by 10 parts of methylnadic anhydride, and other components and operations remain unchanged.

[0075] The obtained mixture has a gel temperature of 153°C, and the obtained epoxy resin cured product has a UL-94 grade of V-2, a limiting oxygen index of 27.8%, a glass transition temperature of 94°C, a tensile strength of 59MPa, and an impact strength of 10.7kJ / m 2 Epoxy resin cured products There was no significant change in epoxy resin cured products after being treated at a temperature of 100°C and a pressure of 1 MPa for 12 hours, or after being heated in a glycerol / NMP solution at 65°C for 120 hours.

[0076] The inventors of the present case also tested the properties of the epoxy resin cured products obtained in the above Examples 1-6 and Comparative Examples 1-3, and the results are shown in Table 1.

[0077] Table 1 Properties of epoxy resin cured products obtained in Examples 1-6 and Comparative Examples 1-3

[0078]

[0079] In addition, the inventors of this case also referred to the aforementioned embodiments and conducted experiments with other raw materials, process operations, and process conditions described in this specification. For example, the curing agents in Examples 1-6 were replaced with malonic acid, succinic acid, dicarboxylic acids with a carbon number greater than 4, alicyclic anhydrides, terephthalic acid, phthalic acid, isophthalic acid, itaconic acid, fumaric acid, maleic acid, succinic acid, malic acid, tartaric acid, citric acid, aliphatic anhydrides, methylhexahydrophthalic anhydride, high phthalic anhydride, phenylmaleic anhydride, phenylmaleic anhydride, 1,8-naphthalene dicarboxylic anhydride, 1,2-naphthalene dicarboxylic anhydride, 2,3-pyrazine dicarboxylic anhydride, 3-hydroxyphthalic anhydride, 2,3-naphthalene dicarboxylic anhydride, 2,3-pyridine dicarboxylic anhydride, etc., and relatively ideal results were obtained.

[0080] The various aspects, embodiments, features and examples of the present invention should be considered as illustrative in all aspects and are not intended to limit the present invention, the scope of the present invention is defined only by the claims. Other embodiments, modifications and uses will be apparent to those skilled in the art without departing from the spirit and scope of the claimed invention.

[0081] Although the present invention has been described with reference to illustrative embodiments, it will be appreciated by those skilled in the art that various other changes, omissions and / or additions may be made and that elements of the described embodiments may be substituted with substantial equivalents without departing from the spirit and scope of the present invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the present invention without departing from the scope of the present invention. Therefore, it is not intended herein to limit the present invention to the specific disclosed embodiments for carrying out the present invention, but rather it is intended that the present invention will include all embodiments within the scope of the appended claims.

Claims

1. A method for degrading a cured epoxy resin, characterized in that: include: In the presence of amine and / or alcohol, the epoxy resin cured product is mixed with a solvent to achieve aminolysis or alcoholysis, wherein the aminolysis or alcoholysis is carried out in an environment of 0 to 200° C. for 1 to 120 hours, the alcohol is selected from any one or a combination of two of a monoalcohol, a diol and a polyol containing C1 to C20, and the amine is selected from any one or a combination of two of a monoamine, a diamine and a polyamine containing C1 to C20; The epoxy resin cured material is formed by curing a flame-retardant and easily degradable epoxy resin precursor, wherein the flame-retardant and easily degradable epoxy resin precursor comprises the following components calculated by weight: 40-50 parts of epoxy resin monomer, 25-30 parts of curing agent, 10-15 parts of phytate, and 1-5 parts of auxiliary agent, wherein the epoxy resin monomer is selected from any one or a combination of two or more of bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, 4,4'-dihydroxydiphenyl sulfide epoxy resin, 4,4'-dihydroxybenzophenone epoxy resin, and hydrogenated bisphenol epoxy resin, the curing agent is selected from an acid curing agent and / or an acid anhydride curing agent, and the phytate is selected from any one or a combination of two or more of calcium phytate, potassium phytate, sodium phytate, and zinc phytate, wherein the phytate serves as a reactive flame retardant, a curing accelerator, and an ester exchange catalyst; the epoxy resin cured material has the following general formula: Wherein, R1 and R2 correspond to the main structure of the epoxy resin monomer and the main structure of the curing agent respectively, R3 corresponds to the main structure of the reactive diluent, or R3 is the same as R2, and the structure of R4 is Wherein, M is selected from any one or a combination of two or more of calcium, potassium, sodium and zinc, and the value of n corresponds to the valence state of M; The gel temperature of the flame-retardant and easily degradable epoxy resin precursor is 100-130° C., the flame retardancy grade of the epoxy resin cured product is UL-94V-0, the limiting oxygen index is higher than 35%, the glass transition temperature is 90-120° C., the tensile strength is 60-80 MPa, and the impact strength is 10-14 kJ / m 2 .

2. The method for degrading a cured epoxy resin material according to claim 1, wherein: The curing agent is selected from any one or a combination of two or more of adipic acid, malonic acid, succinic acid, dicarboxylic acid with a carbon number greater than 4, alicyclic anhydride, terephthalic acid, phthalic acid, isophthalic acid, itaconic acid, fumaric acid, maleic acid, succinic acid, malic acid, tartaric acid, citric acid, aliphatic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, pyromellitic dianhydride, high phthalic anhydride, biphenyl anhydride, phenylmaleic anhydride, phthalic anhydride, 1,8-naphthalene dicarboxylic anhydride, 1,2-naphthalene dicarboxylic anhydride, 2,3-pyrazine dicarboxylic anhydride, 3-hydroxyphthalic anhydride, 2,3-naphthalene dicarboxylic anhydride, and 2,3-pyridine dicarboxylic anhydride.

3. The method for degrading a cured epoxy resin material according to claim 1, wherein: The auxiliary agent is selected from any one or a combination of two or more of active diluents, curing accelerators, antioxidants, anti-aging agents, thixotropic agents, defoaming agents, dispersants, and colorants.

4. The method for degrading a cured epoxy resin material according to claim 1, wherein: The preparation method of the epoxy resin cured product comprises: heating the flame-retardant and easily degradable epoxy resin precursor to 55-80° C. and curing it for 1-10 hours, then curing it at 80-100° C. for 1-5 hours, and finally curing it at 100-130° C. for 1-10 hours to obtain the epoxy resin cured product.

5. The method for degrading a cured epoxy resin material according to claim 1, wherein: The alcohol is selected from any one of ethylene glycol, glycerol, and tert-butyl alcohol, or a combination of two thereof.

6. The method for degrading a cured epoxy resin material according to claim 1, characterized in that: The amine is selected from any one of ethylenediamine, propylenediamine and diethylenetriamine or a combination of two thereof.

7. The method for degrading a cured epoxy resin material according to claim 1, characterized in that: The solvent is selected from any one or a combination of two or more of acetone, butanone, ethyl acetate, propyl acetate, butyl acetate, dichloromethane, chloroform, ether, tetrahydrofuran, dioxane, dimethyl sulfoxide, acetonitrile, N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone.

8. A method for reshaping a cured epoxy resin, characterized in that: include: Reshaping the epoxy resin cured product under hot pressing / no catalysis conditions, wherein the reshaping conditions include: temperature of 100 to 200° C., pressure of 1 to 30 MPa, and reshaping time of 0.1 to 12 hours; The epoxy resin cured material is formed by curing a flame-retardant and easily degradable epoxy resin precursor, wherein the flame-retardant and easily degradable epoxy resin precursor comprises the following components calculated by weight: 40-50 parts of epoxy resin monomer, 25-30 parts of curing agent, 10-15 parts of phytate, and 1-5 parts of auxiliary agent, wherein the epoxy resin monomer is selected from any one or a combination of two or more of bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, 4,4'-dihydroxydiphenyl sulfide epoxy resin, 4,4'-dihydroxybenzophenone epoxy resin, and hydrogenated bisphenol epoxy resin, the curing agent is selected from an acid curing agent and / or an acid anhydride curing agent, and the phytate is selected from any one or a combination of two or more of calcium phytate, potassium phytate, sodium phytate, and zinc phytate, wherein the phytate serves as a reactive flame retardant, a curing accelerator, and an ester exchange catalyst; the epoxy resin cured material has the following general formula: Wherein, R1 and R2 correspond to the main structure of the epoxy resin monomer and the main structure of the curing agent respectively, R3 corresponds to the main structure of the reactive diluent, or R3 is the same as R2, and the structure of R4 is Wherein, M is selected from any one or a combination of two or more of calcium, potassium, sodium and zinc, and the value of n corresponds to the valence state of M; The gel temperature of the flame-retardant and easily degradable epoxy resin precursor is 100-130° C., the flame retardancy grade of the epoxy resin cured product is UL-94V-0, the limiting oxygen index is higher than 35%, the glass transition temperature is 90-120° C., the tensile strength is 60-80 MPa, and the impact strength is 10-14 kJ / m 2 .

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