Flame-retardant fast-curing epoxy resin composition, preparation method thereof and composite material based on epoxy resin composition

Abstract

The invention discloses a flame-retardant fast-curing epoxy resin composition, a preparation method thereof and a composite material based on the epoxy resin composition. The flame-retardant fast-curing epoxy resin composition comprises a component A and a component B. The component A comprises epoxy resin, a flexibilizer, a diluent, a flame retardant and an impregnating compound, and the component B comprises a curing agent, an auxiliary flame retardant and an accelerant. The epoxy resin composition is applied to a wet molding process or an HP-RTM molding process, and specifically, large-tow carbon fibers are infiltrated by the epoxy resin composition, and then the composite material is prepared through the wet molding process or the HP-RTM molding process. The epoxy resin compound provided by the invention ensures good mechanical properties while having rapid curing agent flame retardance; and the epoxy resin composition is suitable for a process for forming a composite material with a large-tow carbon fiber fabric through wet molding / high-pressure resin transfer molding, the yield is improved, and the process adaptability is good.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of epoxy resin, in particular to a flame-retardant rapid curing epoxy resin composition, a preparation method thereof and a composite material based on the epoxy resin composition. BACKGROUND

[0002] Epoxy resin has excellent adhesion and mechanical properties, low curing shrinkage, and good chemical corrosion resistance, and can be widely used in adhesive, coating, composite material and other fields. However, epoxy resin is flammable, and its flame retardance can be improved by flame-retardant modification. At present, the flame-retardant modification of epoxy resin is mainly by adding solid filler flame retardants such as aluminum hydroxide and ammonium polyphosphate into the epoxy resin system, but the addition of such flame retardants will reduce the crosslinking density of the system, resulting in a decrease in the mechanical properties of the product. At the same time, since such flame retardants are inorganic solids, they cannot be dissolved in the system, which not only causes the problem of easy sedimentation during storage, but also causes the viscosity to increase due to the addition of fillers, so the resin and curing agent cannot be mixed uniformly instantaneously, thus cannot meet the requirements of vacuum infusion, HP-RTM and other composite material forming processes.

[0003] By combining epoxy resin with glass fiber, carbon fiber and other materials to form a composite material, the product not only has the characteristics of epoxy resin and fiber materials, and the performance is comparable to that of metal materials, but also can greatly reduce the weight of the product. By reasonably selecting the formula of epoxy resin, such as selecting more heat and humidity resistant resins, curing agents, flame retardants and other materials, and adding various additives, the combination of resin and fiber can be effectively improved, the generation of bubbles in the system can be reduced, defoaming can be faster, and the hydrolysis of the material can be slowed down or prevented. At present, epoxy resin composites are mainly prepared by vacuum infusion, hand lay-up, molding, pultrusion, winding and other processes. Wet compression molding (WCM) and high pressure resin transfer molding (HP-RTM) are two advanced composite material forming processes, which are widely used in the manufacturing of high performance fiber reinforced composites in the fields of automobiles, aerospace, wind power and other fields, which can greatly shorten the production process cycle of composites, and also can ensure the stability of product quality.

[0004] However, the process adaptability of the rapid curing epoxy resin for wet compression molding / high pressure resin transfer molding (HP-RTM) to large tow carbon fiber fabric is poor. When some rapid curing or flame-retardant epoxy resins pursue the improvement of certain performance, other performances are often sacrificed, such as the decrease of mechanical properties and the deterioration of chemical corrosion resistance, thus cannot meet the performance requirements of the composite materials prepared by WCM / HP-RTM process. SUMMARY

[0005] In view of the problems in the prior art, the present application provides a flame-retardant fast-curing epoxy resin composition, a preparation method thereof and a composite material based on the epoxy resin composition, which has fast-curing agent flame retardancy while ensuring good mechanical properties; and the epoxy resin composition is suitable for the process of wet molding / high-pressure resin transfer molding of a composite material with large-tow carbon fiber fabric, which has improved yield and good process adaptability.

[0006] In order to achieve the above-mentioned application purposes, the present application provides the following technical solutions:

[0007] A flame-retardant fast-curing epoxy resin composition comprises A component and B component, wherein the A component comprises epoxy resin, toughening agent, diluent, flame retardant and wetting agent, and the B component comprises curing agent, auxiliary flame retardant and accelerator.

[0008] The mass fraction of each component in the A component is as follows:

[0009] Epoxy resin 50-70 parts,

[0010] Toughening agent 10-15 parts,

[0011] Diluent 5-10 parts,

[0012] Wetting agent 0.5-2 parts,

[0013] Flame retardant 12-20 parts;

[0014] The mass fraction of each component in the B component is as follows:

[0015] Auxiliary flame retardant 3-5 parts,

[0016] Curing agent 10-15 parts,

[0017] Accelerator 1-5 parts;

[0018] The mass fraction of each component in the A component and the B component is consistent;

[0019] The overall system viscosity of the A component mixture is 100-500 mPa·s;

[0020] The viscosity of the epoxy resin is 100-1200 mPa·s, and is specifically selected from any one or more than one of any proportion mixture of bisphenol A epoxy resin, bisphenol F epoxy resin, phenol type epoxy resin and modified epoxy resin, wherein the modified epoxy resin is obtained by core-shell rubber toughening modification of epoxy resin, and has better toughness after modification.

[0021] The toughening agent is a flexible chain segment-containing toughening agent, and is specifically selected from any one or more than one of CTBN-carboxyl-terminated butadiene-acrylonitrile rubber, ATBN-amine-terminated butadiene-acrylonitrile rubber, ETBN-epoxy-terminated butadiene-acrylonitrile rubber, polyether sulfone, and polysulfide rubber in any proportion.

[0022] The diluent is selected from glycidyl ethers, and is specifically selected from any one or more than one of ethylene glycol diglycidyl ether, C12-C14 alkyl glycidyl ether, benzyl glycidyl ether, and 1,4-butanediol diglycidyl ether in any proportion. The diluent can be dissolved or dispersed in the resin, interact with the resin molecules, change the intermolecular forces in the resin system, such as hydrogen bonds, van der Waals forces, etc., so as to reduce the viscosity of the resin system; the dissolution or dispersion effect makes the resin flow more easily, improves the processing performance and flowability of the resin, and facilitates uniform distribution and filling of fiber voids in the mold.

[0023] The infiltrant is an organosiloxane or modified polysiloxane, and the interfacial shear strength retention rate thereof is ≥ 90%, wherein the modified polysiloxane is an alkyl-modified polysiloxane. The infiltrant generally has the dual properties of fiber affinity and resin affinity, part of the molecular structure thereof can interact with the chemical groups on the surface of the fiber, and the other part is compatible with the resin system. This property enables the infiltrant to form a transition layer between the fiber and the resin, thereby reducing the interfacial tension therebetween and improving the wettability of the resin to the fiber; in addition, the infiltrant forms a molecular bridge between the fiber and the resin, thereby enhancing the interaction therebetween and improving their compatibility; this can enable the resin to better wrap the fiber, reduce the voids between the fiber bundles, enhance the compactness of the composite material, and further improve the mechanical properties of the composite material, such as the bending strength, tensile strength, and interlaminar shear strength.

[0024] The flame retardant is tetra-bromobisphenol A epoxy resin (TBBPA-EP) or a phosphorus-based reactive flame retardant (such as a DOPO derivative), and the auxiliary flame retardant is a phosphoric acid ester (such as resorcinol bis-diphenyl phosphate), a polyphosphazene (such as hexaphenoxy cyclotriphosphazene), or an organic silicon-modified flame retardant; and when the flame retardant is tetra-bromobisphenol A epoxy resin, the auxiliary flame retardant is a phosphoric acid ester; when the auxiliary flame retardant is a polyphosphazene, the flame retardant is a phosphorus-based reactive flame retardant or tetra-bromobisphenol A epoxy resin.

[0025] The bromine-phosphorus synergistic system is formed by compounding tetrabromobisphenol A epoxy resin and phosphate in the application, which synchronously improves the condensation phase and gas phase flame retardant efficiency; polyphosphazene (such as hexaphenoxy cyclotriphosphazene) has excellent hydrolysis resistance, and is mixed with amine curing agent (such as alicyclic amine) in the B component, and the phosphorus-nitrogen-bromine triple synergism improves the carbon residue rate and anti-dripping property when the brominated epoxy resin is compounded. The silicone modified flame retardant, as the B component aid, can improve the thermal stability of the cured product. The application uses the synergistic effect of the flame retardant and the auxiliary flame retardant to make the material achieve a higher flame retardant grade, such as UL94 V-0 grade; compared with a single flame retardant, the synergistic flame retardant system has more excellent flame retardant performance under the same amount of addition, and can be used in new energy vehicles, aerospace and other fields with high flame retardant requirements; and through the synergistic effect of different flame retardants, the amount of a single flame retardant can be reduced, thereby reducing the negative impact on the mechanical properties, heat resistance and other properties of the material. The auxiliary flame retardant described in the application can improve the compatibility of the flame retardant and the resin, making the system more uniform, which helps to improve the mechanical properties and processing properties of the material; different flame retardants work in different temperature ranges, and the synergistic effect can make the material have good flame retardant performance in a wider temperature range, improving the use reliability and safety of the material.

[0026] The curing agent is a modified aromatic amine (such as DETDA) or an acid anhydride curing agent, and is specifically selected from any one or more than one of diethylene triamine, triethylene tetramine, phthalic anhydride, trimellitic anhydride, maleic anhydride and hexahydrophthalic anhydride in any proportion.

[0027] The accelerator is selected from any one or more than one of 2-methyl imidazole, 2-ethyl-4-methyl imidazole, 2,4,6-tris (dimethyl aminomethyl) phenol, benzyl dimethyl amine, triphenyl phosphine and quaternary phosphorus compounds in any proportion.

[0028] Due to the HP-RTM process, the resin system must select a low viscosity resin, such as bisphenol A epoxy resin. In addition, the addition of diluent to the low viscosity resin further reduces the viscosity, such as 1,4-butanediol diglycidyl ether, so that the mixed viscosity is 100-500 mPa·s. However, the addition of diluent reduces the thermal performance, flame retardant performance and mechanical properties of the resin, and to some extent, prolongs the gel time. Considering the process requirements, the HP-RTM resin needs to have good flame retardant performance, mechanical properties and thermal performance, and to achieve rapid curing under certain conditions, therefore the addition amount of diluent is preferably 5-10 parts. Since the large tow carbon fiber has a large tow, the resin also needs to further improve the wettability, and therefore a suitable wetting agent needs to be selected to reduce the defects at the interface between the fiber and the resin. The selection of the wetting agent and the diluent interacts with the matrix resin in the system, so that the HP-RTM resin has good process adaptability.

[0029] Further, the present application also provides a preparation method of the above-mentioned flame-retardant fast-curing epoxy resin composition, comprising the following steps:

[0030] (1) accurately weigh the epoxy resin and toughening agent, melt in a high-speed dispersion machine for 1-1.5 hours, and then add the weighed diluent, wetting agent and flame retardant after complete melting, stir until uniform to obtain the epoxy resin composition system component A;

[0031] (2) add the auxiliary flame retardant to the weighed curing agent, stir uniformly at constant temperature, then add the accelerator, stir uniformly at constant temperature to obtain the epoxy resin composition system component B;

[0032] (3) mix the component A obtained in step (1) with the component B obtained in step (2) to obtain the epoxy resin composition of the present application.

[0033] Further, the present application also provides an application of the above-mentioned flame-retardant fast-curing epoxy resin composition in a wet molding or HP-RTM forming process.

[0034] Further, the present application also provides a composite material based on the above-mentioned flame-retardant fast-curing epoxy resin composition, which is prepared by infiltrating the above-mentioned epoxy resin composition into large-tow carbon fibers and then through a wet molding or HP-RTM forming process.

[0035] Further, the present application also provides a forming process of the above-mentioned composite material, comprising the following steps:

[0036] (1) mold installation and preheating: install the mold on the injection machine and check the sealing of the mold to ensure that no resin leakage occurs during the injection process, and then heat the mold to the temperature required by the forming process, 130±5℃;

[0037] (2) fiber selection and layering: select appropriate fiber reinforced materials such as carbon fibers, cut them according to the shape and size of the composite product, and lay the cut fiber materials in the above-mentioned preheated mold;

[0038] (3) injection: use high-pressure injection equipment to inject the preheated temperature of 100±5℃ A and B components into the mold cavity of the pre-laid fiber preform and insert, the injection pressure is 1.0-15.0MPa, and the injection speed should be moderate to ensure that the resin composition can uniformly infiltrate the fiber;

[0039] (4) impregnation and air exhaust: the resin composition gradually infiltrates the fiber preform during the flow process, while the air in the cavity is exhausted to prevent the generation of bubbles;

[0040] (5) Curing: the resin gradually solidifies under the action of the mold temperature and the heat of self-reaction of the resin composition, and the curing time is generally 2-5 min;

[0041] (6) Demolding and trimming: after the curing is completed, the mold is opened, the composite product is taken out of the mold, and finally trimming operations such as edge trimming and deburring are performed on the composite product, and the residual resin and impurities on the surface are cleaned to obtain the finished composite product.

[0042] The injection pressure in step (3) of the present application is generally between 1.0-15.0 MPa, the larger mold gap and higher injection pressure, and the low viscosity resin greatly improve the injection speed of the resin and shorten the molding process cycle;

[0043] The temperature of the resin before injection in step (3) of the present application is generally set at about 100±5℃, which helps to reduce the viscosity of the resin and improve its flowability, making it easier to infiltrate the fibers;

[0044] The setting of the mold temperature in step (1) of the present application is also very important, and is generally maintained at about 130±5℃ to ensure the curing speed of the resin and the quality of the product;

[0045] The curing time in step (5) of the present application is generally set at about 2-5 min, but it can also be adjusted according to the specific resin system, mold temperature and thickness of the product, etc.

[0046] Since the large-tow carbon fibers are difficult to infiltrate, the epoxy resin system needs to have a lower viscosity, and the injection pressure needs to be increased, and the temperature before injection needs to be increased;

[0047] Compared with the prior art, the present application has the following beneficial effects:

[0048] (1) The specific formulation under the joint action makes the resin system achieve rapid curing while achieving V0 level of flame retardation, has good infiltration to the large-tow carbon fiber fabric, and has excellent process adaptability, and the interlaminar shear strength of the composite material after forming with the large-tow carbon fiber is high.

[0049] (2) The yield of the composite material formed by the epoxy resin composition of the present application and the large-tow carbon fiber fabric is improved, and the process adaptability is good; at the same time, it has good mechanical properties, and the specific ratio of the diluent, the infiltration agent and the resin in the formulation will achieve the corresponding effect. BRIEF DESCRIPTION OF DRAWINGS

[0050] Figure 1 The Tg curve of the epoxy resin composition described in Example 5 of the present application. DETAILED DESCRIPTION

[0051] The present application will be described in detail below through examples.

[0052] Example 1

[0053] A flame-retardant fast-curing epoxy resin composition comprising an A component and a B component, wherein the A component comprises an epoxy resin bisphenol A epoxy resin, a toughening agent CTBN-carboxyl-terminated butadiene rubber, a diluent 1,4-butanediol diglycidyl ether, a flame retardant tetrabromobisphenol A epoxy resin (TBBPA-EP), and an infiltration agent alkyl-modified polysiloxane, and the B component comprises a curing agent diethylenetriamine, an auxiliary flame retardant resorcinol bis-diphenyl phosphate, and a promoter 2-methylimidazole;

[0054] The mass fraction of each component in the A component is as follows:

[0055]

[0056] The mass fraction of each component in the B component is as follows:

[0057] The auxiliary flame retardant is 3 parts,

[0058] The curing agent is 10 parts,

[0059] The promoter is 1 part;

[0060] And the mass fraction of each component in the A component and the B component is consistent.

[0061] Example 2

[0062] A flame-retardant fast-curing epoxy resin composition comprising an A component and a B component, wherein the A component comprises an epoxy resin phenol-type epoxy resin, a toughening agent CTBN-carboxyl-terminated butadiene rubber, a diluent 1,4-butanediol diglycidyl ether, a flame retardant tetrabromobisphenol A epoxy resin (TBBPA-EP), and an infiltration agent alkyl-modified polysiloxane, and the B component comprises a curing agent phthalic anhydride, an auxiliary flame retardant resorcinol bis-diphenyl phosphate, and a promoter benzyl dimethylamine;

[0063] The mass fraction of each component in the A component is as follows:

[0064] The epoxy resin is 70 parts,

[0065] The toughening agent is 10 parts,

[0066] The diluent is 7 parts,

[0067] The infiltration agent is 1 part,

[0068] The flame retardant is 12 parts;

[0069] The mass fraction of each component in the B component is as follows:

[0070] The auxiliary flame retardant is 3 parts,

[0071] The curing agent is 10 parts,

[0072] Promoter 1 part;

[0073] and the mass fraction of each component in the A component and the B component is consistent.

[0074] Example 3

[0075] A flame-retardant fast-curing epoxy resin composition, comprising an A component and a B component, wherein the A component comprises an epoxy resin bisphenol A epoxy resin, a toughening agent CTBN-carboxyl-terminated butadiene acrylonitrile rubber, a diluent ethylene glycol diglycidyl ether, a flame retardant TBBPA-EP, and an infiltration agent polydimethylsiloxane, and the B component comprises a curing agent triethylene tetramine, an auxiliary flame retardant resorcinol bisphenyl phosphate, and a promoter 2-ethyl-4-methylimidazole;

[0076] The mass fraction of each component in the A component is as follows:

[0077] Epoxy resin 70 parts,

[0078]

[0079] The mass fraction of each component in the B component is as follows:

[0080] Auxiliary flame retardant 3 parts,

[0081] Curing agent 12 parts,

[0082] Promoter 3 parts;

[0083] and the mass fraction of each component in the A component and the B component is consistent.

[0084] Example 4

[0085] A flame-retardant fast-curing epoxy resin composition, comprising an A component and a B component, wherein the A component comprises an epoxy resin bisphenol A epoxy resin, a toughening agent CTBN-carboxyl-terminated butadiene acrylonitrile rubber, a diluent ethylene glycol diglycidyl ether, a flame retardant TBBPA-EP, and an infiltration agent polydimethylsiloxane, and the B component comprises a curing agent triethylene tetramine, an auxiliary flame retardant resorcinol bisphenyl phosphate, and a promoter 2-ethyl-4-methylimidazole;

[0086] The mass fraction of each component in the A component is as follows:

[0087]

[0088] The mass fraction of each component in the B component is as follows:

[0089] Auxiliary flame retardant 3 parts,

[0090] Curing agent 12 parts,

[0091] Promoter 3 parts;

[0092] and the mass fraction of each component in the A component and the B component is consistent.

[0093] Example 5

[0094] A flame-retardant fast-curing epoxy resin composition, comprising an A component and a B component, wherein the A component comprises an epoxy resin bisphenol F epoxy resin, a toughening agent ETBN-epoxy-terminated nitrile rubber, a diluent C12-C14 alkyl glycidyl ether, a flame retardant DOPO derivative and an infiltration agent polydimethylsiloxane, the B component comprises a curing agent triethylenetetramine, an auxiliary flame retardant hexaphenoxycyclotriphosphazene and a promoter triphenylphosphine;

[0095] The mass fraction of each component in the A component is as follows:

[0096]

[0097] The mass fraction of each component in the B component is as follows:

[0098] Auxiliary flame retardant 3 parts,

[0099] Curing agent 12 parts,

[0100] Promoter 3 parts;

[0101] and the mass fraction of each component in the A component and the B component is consistent.

[0102] Example 6

[0103] A flame-retardant fast-curing epoxy resin composition, comprising an A component and a B component, wherein the A component comprises an epoxy resin modified epoxy resin, a toughening agent CTBN-carboxyl-terminated nitrile rubber, a diluent C12-C14 alkyl glycidyl ether, a flame retardant TBBPA-EP and an infiltration agent polydimethylsiloxane, the B component comprises a curing agent triethylenetetramine, an auxiliary flame retardant resorcinol bis diphenyl phosphate and a promoter 2,4,6-tris(dimethylaminomethyl) phenol;

[0104] The mass fraction of each component in the A component is as follows:

[0105]

[0106] The mass fraction of each component in the B component is as follows:

[0107] Auxiliary flame retardant 5 parts,

[0108] Curing agent 15 parts,

[0109] Promoter 5 parts;

[0110] and the mass fraction of each component in the A component and the B component is consistent.

[0111] Example 7

[0112] A flame-retardant fast-curing epoxy resin composition comprises an A component and a B component, wherein the A component comprises an epoxy resin phenol type epoxy resin, a toughening agent poly-sulfur rubber, a diluent benzyl glycidyl ether, a flame retardant TBBPA-EP and an infiltrant methyl trimethoxysilane, the B component comprises a curing agent maleic anhydride, an auxiliary flame retardant resorcinol bis-diphenyl phosphate and a promoter 2-ethyl-4-methyl imidazole.

[0113] The mass fraction of each component in the A component is as follows:

[0114] Epoxy resin 70 parts,

[0115] Toughening agent 10 parts,

[0116] Diluent 10 parts,

[0117] Infiltrant 2 parts,

[0118] Flame retardant 20 parts;

[0119] The mass fraction of each component in the B component is as follows:

[0120] Auxiliary flame retardant 5 parts,

[0121] Curing agent 15 parts,

[0122] Promoter 5 parts;

[0123] and the mass fraction of each component in the A component and the B component is consistent.

[0124] Comparative Example 1

[0125] A flame-retardant fast-curing epoxy resin composition comprises an A component and a B component, wherein the A component comprises an epoxy resin modified epoxy resin, a toughening agent CTBN-carboxyl-terminated nitrile rubber, a flame retardant TBBPA-EP and an infiltrant polydimethylsiloxane, the B component comprises a curing agent triethylene tetramine, an auxiliary flame retardant resorcinol bis-diphenyl phosphate and a promoter 2,4,6-tris(dimethylaminomethyl) phenol.

[0126] The mass fraction of each component in the A component is as follows:

[0127] Epoxy resin 70 parts,

[0128] Toughening agent 15 parts,

[0129] Infiltrant 2 parts,

[0130] Flame retardant 20 parts;

[0131] The mass fraction of each component in the B component is as follows:

[0132] Auxiliary flame retardant 5 parts,

[0133] Curing agent 15 parts,

[0134] Promoter 5 parts;

[0135] And the mass fraction of each component in the A component and the B component is consistent.

[0136] Comparative Example 2

[0137] A flame-retardant fast-curing epoxy resin composition includes an A component and a B component, wherein the A component includes an epoxy resin, a toughening agent, a diluent, a flame retardant, and a wetting agent, and the B component includes a curing agent, an auxiliary flame retardant, and a promoter;

[0138] The mass fraction of each component in the A component is as follows:

[0139] Epoxy resin 70 parts,

[0140] Toughening agent 15 parts,

[0141] Diluent 15 parts,

[0142] Wetting agent 2 parts,

[0143] Flame retardant 20 parts;

[0144] The mass fraction of each component in the B component is as follows:

[0145] Auxiliary flame retardant 5 parts,

[0146] Curing agent 15 parts,

[0147] Promoter 5 parts;

[0148] And the mass fraction of each component in the A component and the B component is consistent.

[0149] Comparative Example 3

[0150] A flame-retardant fast-curing epoxy resin composition includes an A component and a B component, wherein the A component includes an epoxy resin, a toughening agent, a diluent, and a flame retardant, and the B component includes a curing agent, an auxiliary flame retardant, and a promoter;

[0151] The mass fraction of each component in the A component is as follows:

[0152] epoxy resin 70 parts,

[0153] toughening agent 15 parts,

[0154] diluent 10 parts,

[0155] flame retardant 20 parts;

[0156] The mass fraction of each component in the B component is as follows:

[0157] auxiliary flame retardant 5 parts,

[0158] curing agent 15 parts,

[0159] accelerator 5 parts;

[0160] and the mass fraction of each component in the A component and the B component is consistent.

[0161] Comparative Example 4

[0162] A flame-retardant fast-curing epoxy resin composition includes an A component and a B component, wherein the A component includes an epoxy resin bisphenol F epoxy resin, a toughening agent ETBN-epoxy-terminated nitrile rubber, a diluent C12-C14 alkyl glycidyl ether, a flame retardant DOPO derivative, and a wetting agent polydimethylsiloxane, and the B component includes a curing agent triethylenetetramine and an accelerator 2-ethyl-4-methylimidazole;

[0163] The mass fraction of each component in the A component is as follows:

[0164] epoxy resin 70 parts,

[0165] toughening agent 15 parts,

[0166] diluent 10 parts,

[0167] wetting agent 2 parts,

[0168] flame retardant 20 parts;

[0169] The mass fraction of each component in the B component is as follows:

[0170] curing agent 15 parts,

[0171] accelerator 5 parts;

[0172] and the mass fraction of each component in the A component and the B component is consistent.

[0173] Comparative Example 5

[0174] A flame-retardant fast-curing epoxy resin composition comprises A component and B component, wherein the A component comprises epoxy resin bisphenol A epoxy resin, diluent 1,4-butanediol diglycidyl ether, flame retardant TBBPA-EP and wetting agent alkyl-modified polysiloxane, the B component comprises curing agent diethylene triamine, auxiliary flame retardant resorcinol bis-diphenyl phosphate and accelerator 2-methyl imidazole;

[0175] The mass fraction of each component in the A component is as follows:

[0176] Epoxy resin 70 parts,

[0177] Diluent 10 parts,

[0178] Wetting agent 2 parts,

[0179] Flame retardant 20 parts;

[0180] The mass fraction of each component in the B component is as follows:

[0181] Auxiliary flame retardant 5 parts,

[0182] Curing agent 15 parts,

[0183] Accelerator 5 parts;

[0184] And the mass fraction of each component in the A component and the B component is consistent.

[0185] Application examples

[0186] The epoxy resin composition prepared in each example and comparative example is applied to a wet molding or HP-RTM forming process to prepare a composite material, and the specific forming process is as follows:

[0187] (1) Mould installation and preheating: the mould is installed on the injection machine, and the sealing property of the mould is checked to ensure that no resin leakage occurs during the injection process, and then the mould is heated to the temperature required by the forming process, i.e. 130±5℃;

[0188] (2) Fiber selection and layering: select appropriate fiber reinforced materials, such as carbon fibers, and cut them according to the shape and size of the composite product, and then layer the cut fiber materials in the preheated mould;

[0189] (3) Injection: inject the A component and the B component with a preheating temperature of 100±5℃ into the mould cavity of the mould in which the fiber preform and the insert are pre-laid, using a high-pressure injection device, the injection pressure is 1.0-15.0 MPa, and the injection speed should be moderate to ensure that the resin composition can uniformly impregnate the fibers;

[0190] (4) Impregnation and venting: the resin composition gradually impregnates the fiber preform during flowing, and at the same time, the air in the cavity is discharged to prevent the generation of air bubbles;

[0191] (5) Curing: the resin gradually cures under the action of the mold temperature and the reaction heat of the resin composition itself, and the curing time is generally 2-5 min;

[0192] (6) Demolding and trimming: after curing is completed, the mold is opened, the composite product is taken out of the mold, and finally trimming operations such as edge trimming and deburring are performed on the composite product, and the residual resin and impurities on the surface are cleaned to obtain a composite product.

[0193] The composite materials prepared by using the epoxy resin compositions of each example and the comparative example were subjected to performance detection, and the detection results are shown in Table 1.

[0194] Table 1 Performance detection results of the composite materials prepared by using the epoxy resin compositions of each example and the comparative example

[0195]

[0196] It can be found from the results in Table 1 that the addition of an excess of the diluent can reduce the Tg, which does not meet the actual application requirements; too small an amount of the diluent increases the viscosity, which is not convenient for the injection process in the HP-RTM process, and the processability is not good; the interlaminar shear strength reflects the interfacial bonding force of the resin and the carbon fiber, and the higher the interlaminar shear strength, the stronger the interfacial bonding force; at the same time, the addition of the flame retardant also affects the Tg, and the Tg slightly decreases with the increase of the addition amount.

[0197] Figure 1 The Tg curve of the epoxy resin composition described in Example 5 of the present application can be seen to change the glass transition temperature of the epoxy resin composition prepared by the present application.

Claims

1. A flame-retardant, fast-curing epoxy resin composition, characterized in that, The composition comprises A component and B component, wherein the A component comprises epoxy resin, toughening agent, diluent, flame retardant and wetting agent, the B component comprises curing agent, auxiliary flame retardant and accelerator; The mass fraction of each component in the A component is as follows: The mass fraction of each component in the B component is as follows: The auxiliary flame retardant is 3-5 parts, The curing agent is 10-15 parts, The accelerator is 1-5 parts; The mass fraction of each component in the A component and the B component is consistent; The overall viscosity of the A component is 100-500 mPa·s; The viscosity of the epoxy resin is 100-1200 mPa·s; The toughening agent is a flexible chain segment-containing toughening agent; The diluent is selected from glycidyl ethers; The curing agent is a modified aromatic amine or an acid anhydride curing agent; The wetting agent is an organosiloxane or a modified polysiloxane, and the interfacial shear strength retention rate thereof is ≥90%, wherein the modified polysiloxane is an alkyl-modified polysiloxane.

2. The flame retardant fast-curing epoxy resin composition according to claim 1, characterized in that, The epoxy resin is selected from any one or more than one of bisphenol A epoxy resin, bisphenol F epoxy resin, phenol-type epoxy resin, and modified epoxy resin in any proportion; The modified epoxy resin is obtained by core-shell rubber toughening modification of epoxy resin.

3. The flame retardant fast-curing epoxy resin composition according to claim 1, wherein The toughening agent is selected from any one or more than one of CTBN-carboxyl-terminated butyl nitrile rubber, ATBN-amine-terminated butyl nitrile rubber, ETBN-epoxy-terminated butyl nitrile rubber, polyether sulfone, and polysulfide rubber in any proportion.

4. The flame retardant, fast-curing epoxy resin composition according to claim 1, wherein The diluent is selected from any one or more than one of ethylene glycol diglycidyl ether, C12-C14 alkyl glycidyl ether, benzyl glycidyl ether, and 1,4-butanediol diglycidyl ether in any proportion.

5. The flame retardant fast-curing epoxy resin composition according to claim 1, wherein The flame retardant is tetra-bromobisphenol A epoxy resin or a phosphorus-based reactive flame retardant, and the phosphorus-based reactive flame retardant is preferably a DOPO derivative; The auxiliary flame retardant is a phosphoric acid ester, a polyphosphazene, or an organosilicon-modified flame retardant; the phosphoric acid ester is preferably resorcinol bisphenyl phosphate, and the polyphosphazene is preferably hexaphenoxy cyclotriphosphazene; When the flame retardant is tetra-bromobisphenol A epoxy resin, the auxiliary flame retardant is a phosphoric acid ester flame retardant; When the auxiliary flame retardant is a polyphosphazene flame retardant, the flame retardant is a phosphorus-based reactive flame retardant or tetra-bromobisphenol A epoxy resin.

6. The flame retardant, fast-curing epoxy resin composition according to claim 1, wherein The curing agent is selected from any one or more than one of diethylene triamine, triethylene tetramine, phthalic anhydride, trimellitic anhydride, maleic anhydride, and hexahydrophthalic anhydride in any proportion; The accelerator is selected from any one or more than one of 2-methyl imidazole, 2-ethyl-4-methyl imidazole, 2,4,6-tris(dimethyl aminomethyl) phenol, benzyl dimethyl amine, triphenyl phosphine, and quaternary phosphorus compound in any proportion.

7. A method for producing the flame-retardant rapid-curing epoxy resin composition according to any one of claims 1 to 6, characterized by, The method comprises the following steps: (1) accurately weigh the epoxy resin and the toughening agent, melt in a high-speed dispersing machine for 1-1.5 hours, and then add the weighed diluent, wetting agent, and flame retardant after complete melting, stir until uniform, and obtain the epoxy resin composition system A component; (2) add the auxiliary flame retardant to the weighed curing agent, stir uniformly at constant temperature, then add the accelerator, stir uniformly at constant temperature, and obtain the epoxy resin composition system B component; (3) mixing the A component obtained in step (1) with the B component obtained in step (2) to obtain the epoxy resin composition according to the present application.

8. Use of the flame-retardant fast-curing epoxy resin composition according to any one of claims 1 to 6 in a wet compression molding or HP-RTM molding process.

9. A composite material based on the flame-retardant fast-curing epoxy resin composition according to any one of claims 1 to 6, characterized in that: The above-mentioned epoxy resin composition is used to impregnate large-tow carbon fibers, and then a molding process is performed by wet compression molding or HP-RTM molding.

10. A process for forming the composite material of claim 9, wherein, The method comprises the following steps: (1) mold installation and preheating: the mold is installed on the injection machine, and the tightness of the mold is checked to ensure that no resin leakage occurs during the injection process, and then the mold is heated to a temperature of 130±5°C required by the molding process; (2) fiber selection and layering: selecting appropriate fiber reinforced materials such as carbon fibers, and cutting the fiber materials according to the shape and size of the composite product, and then layering the cut fiber materials in the preheated mold; (3) injection: using a high-pressure injection device to inject the A and B components with a preheating temperature of 100±5°C into the mold cavity of the mold in which the fiber preform and inserts are pre-laid, and the injection pressure is 1.0-15.0 MPa, and the injection speed is moderate to ensure that the resin composition can uniformly impregnate the fibers; (4) impregnation and air exhaust: the resin composition gradually impregnates the fiber preform during the flow process, and at the same time, the air in the cavity is exhausted to prevent the generation of air bubbles; (5) curing: under the action of the mold temperature and the reaction heat of the resin composition itself, the resin gradually cures, and the curing time is generally 2-5 min; (6) demolding and trimming: after curing is completed, the mold is opened, and the composite product is taken out of the mold; finally, trimming operations such as edge trimming and deburring are performed on the composite product, and the residual resin and impurities on the surface are cleaned to obtain the finished composite product.

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