Flame-retardant curing agent, flame-retardant epoxy resin composition, flame-retardant epoxy resin material and preparation method thereof

Abstract

The invention relates to the field of epoxy resin, and discloses a flame-retardant curing agent, a flame-retardant epoxy resin composition, a flame-retardant epoxy resin material and a preparation method thereof, and the flame-retardant curing agent contains a reaction product of alicyclic amine, polyethylene polyamine, tertiary amine and phosphate. The flame-retardant epoxy resin composition contains flame-retardant epoxy resin and a flame-retardant curing agent, and the flame-retardant epoxy resin contains a reaction product of bisphenol epoxy resin, novolac epoxy resin, a polyfunctional epoxy diluent and a flame retardant. According to the flame-retardant epoxy resin material, the specific flame-retardant epoxy resin and the flame-retardant curing agent are selected, so that the flame-retardant epoxy resin material has the advantages of being short in curing forming time and excellent in flame-retardant effect, curing forming of the flame-retardant epoxy resin material within 5 min can be achieved, and the flame-retardant grade of the flame-retardant epoxy resin material with the thickness of 0.9-1.5 mm passes the UL94V0 grade.

Description

Technical Field

[0001] The invention relates to the field of epoxy resins, and in particular to a flame retardant curing agent, a flame retardant epoxy resin composition, a flame retardant epoxy resin material and a preparation method thereof. Background Art

[0002] In recent years, many electric vehicles have experienced spontaneous combustion accidents caused by thermal runaway, causing OEMs to attach great importance to the safety of battery packs. The flame retardancy of the shell that loads the battery module and blocks the body floor has become particularly important. At present, in addition to requiring the material of the battery shell to meet the UL94V-0 flame retardant level, the industry also requires the upper shell to pass a strict external fire test. The composite battery pack upper shell produced by the high-pressure resin transfer molding HP-RTM process has great advantages in improving the flame retardancy, safety and lightweight of the battery pack upper shell. At the same time, due to the health hazards of halogen-containing flame retardant materials such as toxic and corrosive gases, halogen-free composite battery packs have become the main direction of development.

[0003] At present, the resin systems that have been publicly reported to meet the UL94V0 standard mainly add a large amount of organic and inorganic powders to epoxy resin to achieve the index, and its mechanical properties will inevitably be greatly reduced. For the HP-RTM process, a large amount of fillers will not only affect the infiltration of resin and fiber, resulting in a decrease in the mechanical properties of the composite material, but also the fillers will block the equipment pipelines.

[0004] CN115286897A discloses a halogen-free flame-retardant HP-RTM epoxy resin and a preparation method thereof, wherein the flame-retardant effect is achieved by adding organic fillers such as ammonium polyphosphate and pentaerythritol to the epoxy resin, reaching the UL94V0 level, but there is a risk of migration of ammonium polyphosphate during use. It is recognized in the industry that the filler-free halogen-free flame-retardant resin has excellent fiber wettability and the corresponding composite material reaches the UL94V0 level.

[0005] The present invention discloses a filler-free halogen-free flame-retardant epoxy resin and a preparation method thereof, wherein 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is modified with epoxy resin to obtain a P-containing flame-retardant epoxy resin, and a phosphate ester and an amine curing agent are modified to obtain a flame-retardant curing agent. By reasonably matching the flame-retardant epoxy resin and the flame-retardant curing agent, a filler-free halogen-free flame-retardant resin system suitable for the HP-RTM process is obtained. Summary of the invention

[0006] The purpose of the present invention is to overcome the problem that organic flame retardant fillers in the prior art lead to poor mechanical properties and process properties of flame retardant epoxy resin systems, and to provide a flame retardant curing agent, a flame retardant epoxy resin composition, a flame retardant epoxy resin material and a preparation method thereof. The flame retardant epoxy resin material of the present invention has the advantages of short curing molding time and excellent flame retardant effect by selecting specific flame retardant epoxy resin and flame retardant curing agent.

[0007] In order to achieve the above object, the first aspect of the present invention provides a flame retardant curing agent, wherein the flame retardant curing agent contains a reaction product of alicyclic amine, polyethylene polyamine, tertiary amine and phosphate.

[0008] Preferably, the alicyclic amine is selected from at least one of isophoronediamine, methylcyclopentanediamine, o-diaminomethylcyclopentane, 1,3-cyclohexanedimethylamine, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, 1,2-cyclohexanediamine or 4,4'-diaminodicyclohexylmethane, menthanediamine and N-aminoethylpiperazine, preferably at least one of isophoronediamine, methylcyclopentanediamine, o-diaminomethylcyclopentane and 1,3-cyclohexanedimethylamine;

[0009] Preferably, the polyethylene polyamine is selected from at least one of diethylenetriamine, triethylenetetramine, tetraethylenepentamine and divinylpropylamine, preferably at least one of diethylenetriamine, triethylenetetramine and tetraethylenepentamine;

[0010] Preferably, the tertiary amine is selected from at least one of tetramethylethylenediamine, tetramethylhexanediamine, dimethylethanolamine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, triethanolamine, o-hydroxybenzyldimethylamine and triethylamine, preferably at least one of tetramethylhexanediamine, benzyldimethylamine, triethanolamine and o-hydroxybenzyldimethylamine;

[0011] Preferably, the phosphate is selected from at least one of triethyl phosphate, trimethyl phosphate, triphenyl phosphate, tolylene diphenyl phosphate, triisobutyl phosphate, diphenyl isodecyl phosphate, triisopropylphenyl phosphate, tributoxyethyl phosphate, tert-butylbenzene diphenyl phosphate and tri(xylene) phosphate, preferably at least one of triethyl phosphate, trimethyl phosphate, triisobutyl phosphate, diphenyl isodecyl phosphate, triisopropylphenyl phosphate and tert-butylbenzene diphenyl phosphate.

[0012] Preferably, the molar ratio of the alicyclic amine, polyethylene polyamine, tertiary amine and phosphate is 1: 0.2-0.5: 0.1-0.3: 0.4-0.7; more preferably 1: 0.25-0.45: 0.12-0.25: 0.45-0.65.

[0013] Preferably, the reaction conditions of the alicyclic amine, polyethylene polyamine, tertiary amine and phosphate include: temperature of 100-130° C., time of 2-4 h;

[0014] More preferably, the reaction conditions of the alicyclic amine, polyethylene polyamine, tertiary amine and phosphate include: temperature of 115-125° C. and time of 150-200 min.

[0015] According to a second aspect of the present invention, a flame retardant epoxy resin composition is provided, wherein the composition contains a flame retardant epoxy resin and the flame retardant curing agent described in the first aspect of the present invention, wherein the flame retardant epoxy resin contains the reaction product of a bisphenol epoxy resin, a phenolic epoxy resin, a multifunctional epoxy diluent and a flame retardant.

[0016] Preferably, the flame retardant epoxy resin composition contains 60-98 wt % of a flame retardant epoxy resin and 10-25 wt % of a flame retardant curing agent;

[0017] Preferably, the flame retardant epoxy resin composition contains 80-95 wt % of the flame retardant epoxy resin and 15-20 wt % of the flame retardant epoxy resin.

[0018] Preferably, the bisphenol epoxy resin is at least one selected from bisphenol A epoxy resin, bisphenol F epoxy resin and hydrogenated bisphenol A epoxy resin, more preferably bisphenol A epoxy resin.

[0019] Preferably, the novolac epoxy resin is selected from at least one of phenol-type novolac epoxy resin, o-cresol novolac epoxy resin and bisphenol A novolac epoxy resin, more preferably at least one of phenol-type novolac epoxy resin and o-cresol novolac epoxy resin.

[0020] Preferably, the multifunctional epoxy diluent is selected from at least one of N,N,N,N,-tetraepoxypropyl-4,4-diaminodiphenylmethane, sorbitol glycidyl ether, cyclohexanediamine tetrafunctional epoxy resin and trimethylolpropane triglycidyl ether, more preferably at least one of N,N,N,N,-tetraepoxypropyl-4,4-diaminodiphenylmethane and sorbitol glycidyl ether.

[0021] Preferably, the flame retardant is selected from at least one of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10-(2,5-dihydroxyphenyl)-10-hydrogen-9-oxa-10-phosphaphenanthrene-10-oxide and [(6-oxo-(6H)-dibenzo-(CE)(1,2)-oxaphosphahexane-6-one)methyl]-succinic acid, more preferably 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide.

[0022] Preferably, the weight ratio of the bisphenol epoxy resin, the novolac epoxy resin, the multifunctional epoxy diluent and the flame retardant is 1:0.2-0.5:0.03-0.2:0.05-0.15, more preferably 1:0.25-0.45:0.05-0.18:0.08-0.13.

[0023] Preferably, the reaction conditions of the bisphenol epoxy resin, novolac epoxy resin, multifunctional epoxy diluent and flame retardant include: temperature of 120-200°C and time of 2-8h; more preferably, the reaction conditions of the bisphenol epoxy resin, novolac epoxy resin, multifunctional epoxy diluent and flame retardant include: temperature of 130-180°C and time of 4-6h.

[0024] According to a third aspect of the present invention, a method for preparing a flame retardant epoxy resin material is provided, wherein the method comprises the step of curing the components of the flame retardant epoxy resin composition.

[0025] Preferably, the curing conditions include: 120-140° C., time 3-5 min; more preferably, the temperature is 130-135° C., time 4-5 min.

[0026] According to a fourth aspect of the present invention, there is provided a flame retardant epoxy resin material prepared by the method described in the third aspect of the present invention.

[0027] Through the above technical scheme, the flame retardant epoxy resin material of the present invention has the advantages of short curing time and excellent flame retardant effect by selecting specific flame retardant epoxy resin and flame retardant curing agent. Specifically, the flame retardant epoxy resin material can be cured within 5 minutes, and the flame retardant grade of the 0.9-1.5mm thick flame retardant epoxy resin material passes the UL94V0 grade. DETAILED DESCRIPTION

[0028] 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.

[0029] According to a first aspect of the present invention, there is provided a flame retardant curing agent, wherein the flame retardant curing agent contains a reaction product of alicyclic amine, polyethylene polyamine, tertiary amine and phosphate ester.

[0030] According to the present invention, in order to modify the flame retardant curing agent to obtain a better flame retardant effect, the alicyclic amine is selected from at least one of isophorone diamine, methylcyclopentane diamine, o-diaminomethylcyclopentane, 1,3-cyclohexanedimethylamine, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, 1,2-cyclohexanediamine or 4,4'-diaminodicyclohexylmethane, menthane diamine and N-aminoethylpiperazine, preferably at least one of isophorone diamine, methylcyclopentane diamine, o-diaminomethylcyclopentane and 1,3-cyclohexanedimethylamine.

[0031] According to the present invention, in order to improve the chemical resistance of the flame retardant epoxy resin material, the polyethylene polyamine is selected from at least one of diethylenetriamine, triethylenetetramine, tetraethylenepentamine and divinylpropylamine, preferably at least one of diethylenetriamine, triethylenetetramine and tetraethylenepentamine.

[0032] Preferably, in order to improve the high reactivity performance of the flame retardant epoxy resin material obtained, the tertiary amine is selected from at least one of tetramethylethylenediamine, tetramethylhexanediamine, dimethylethanolamine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, triethanolamine, o-hydroxybenzyldimethylamine and triethylamine, preferably at least one of tetramethylhexanediamine, benzyldimethylamine, triethanolamine and o-hydroxybenzyldimethylamine.

[0033] Preferably, in order to improve the flame retardant properties of the flame retardant epoxy resin material obtained, the phosphate ester is selected from at least one of triethyl phosphate, trimethyl phosphate, triphenyl phosphate, toluene diphenyl phosphate, triisobutyl phosphate, diphenyl isodecyl phosphate, triisopropylphenyl phosphate, tributoxyethyl phosphate, tert-butylbenzene diphenyl phosphate and tri(xylene) phosphate, and is preferably at least one of triethyl phosphate, trimethyl phosphate, triisobutyl phosphate, diphenyl isodecyl phosphate, triisopropylphenyl phosphate and tert-butylbenzene diphenyl phosphate.

[0034] According to the present invention, the molar ratio of the alicyclic amine, polyethylene polyamine, tertiary amine and phosphate is 1: 0.2-0.5: 0.1-0.3: 0.4-0.7; preferably 1: 0.25-0.45: 0.12-0.25: 0.45-0.65.

[0035] According to the present invention, the reaction conditions of the alicyclic amine, polyethylene polyamine, tertiary amine and phosphate ester include: temperature of 100-130°C and time of 2-4h; more preferably, the reaction conditions of the alicyclic amine, polyethylene polyamine, tertiary amine and phosphate ester include: temperature of 115-125°C and time of 150-200min.

[0036] According to the present invention, the viscosity of the flame retardant curing agent at 25° C. is less than 500 mPa·s, preferably 100-300 mPa·s. Since the viscosity of the flame retardant curing agent at 25° C. is within the above range, it has the advantage of good process performance.

[0037] In the present invention, after the reaction is completed, the step of cooling the reaction product to 60-80° C. and distilling the reaction product may be included. Preferably, the distillation is performed under reduced pressure for 1-4 hours to obtain a flame retardant curing agent.

[0038] According to the present invention, preferably, the reaction of the alicyclic amine, polyethylene polyamine, tertiary amine and phosphate is carried out under an inert atmosphere. The inert atmosphere can be implemented by introducing an inert gas, such as nitrogen, argon, etc.

[0039] In a preferred embodiment of the present invention, the method of reacting alicyclic amine, polyethylene polyamine, tertiary amine and phosphate ester comprises: heating the mixture of alicyclic amine, polyethylene polyamine and tertiary amine to 110-130° C. under an inert atmosphere, adding phosphate ester dropwise, and reacting for 0.5-2h.

[0040] According to a second aspect of the present invention, a flame retardant epoxy resin composition is provided, wherein the composition contains a flame retardant epoxy resin and the flame retardant curing agent described in the first aspect of the present invention, wherein the flame retardant epoxy resin contains the reaction product of a bisphenol epoxy resin, a phenolic epoxy resin, a multifunctional epoxy diluent and a flame retardant.

[0041] According to the present invention, in order to further improve the flame retardant properties, tensile properties, bending properties and shear strength, preferably, the flame retardant epoxy resin composition contains 60-98 weight % of the flame retardant epoxy resin and 10-25 weight % of the flame retardant curing agent; more preferably, the flame retardant epoxy resin composition contains 80-95 weight % of the flame retardant epoxy resin and 5-20 weight % of the flame retardant epoxy resin.

[0042] In the present invention, the flame retardant epoxy resin contains the reaction product of bisphenol epoxy resin, novolac epoxy resin, multifunctional epoxy diluent and flame retardant; preferably, the flame retardant epoxy resin is the reaction product of bisphenol epoxy resin, novolac epoxy resin, multifunctional epoxy diluent and flame retardant.

[0043] According to the present invention, the viscosity of the flame retardant epoxy resin at 25° C. is less than 20000 mPa·s, preferably 6000-15000 mPa·s. Since the viscosity of the flame retardant epoxy resin at 25° C. is within the above range, it has the advantage of good fiber impregnation.

[0044] According to the present invention, in order to improve the heat resistance of the flame-retardant epoxy resin material, the bisphenol epoxy resin can be selected from at least one of bisphenol A epoxy resin and bisphenol F epoxy resin; more preferably, the bisphenol epoxy resin is bisphenol A epoxy resin.

[0045] According to the present invention, in order to improve the moisture and heat resistance of the flame-retardant epoxy resin material obtained, the novolac epoxy resin can be selected from at least one of phenol-type novolac epoxy resin, o-cresol novolac epoxy resin and bisphenol A novolac epoxy resin; preferably, the novolac epoxy resin is selected from at least one of phenol-type novolac epoxy resin and o-cresol novolac epoxy resin.

[0046] According to the present invention, in order to improve the heat resistance of the obtained flame-retardant epoxy resin material, the multifunctional epoxy diluent can be selected from at least one of N,N,N,N,-tetraepoxypropyl-4,4-diaminodiphenylmethane, sorbitol glycidyl ether, cyclohexanediamine tetrafunctional epoxy resin and trimethylolpropane triglycidyl ether; preferably, the multifunctional epoxy diluent is selected from at least one of N,N,N,N,-tetraepoxypropyl-4,4-diaminodiphenylmethane and sorbitol glycidyl ether.

[0047] According to the present invention, in order to improve the flame retardant properties of the obtained flame retardant epoxy resin material, the flame retardant can be selected from at least one of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10-(2,5-dihydroxyphenyl)-10-hydrogen-9-oxa-10-phosphaphenanthrene-10-oxide and [(6-oxygen-(6H)-dibenzo-(CE)(1,2)-oxaphosphahexane-6-one)methyl]-succinic acid; preferably, the flame retardant is 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide.

[0048] According to the present invention, the weight ratio of the bisphenol epoxy resin, the novolac epoxy resin, the multifunctional epoxy diluent and the flame retardant is 1: 0.2-0.5: 0.03-0.2: 0.05-0.15; more preferably, the weight ratio of the bisphenol epoxy resin, the novolac epoxy resin, the multifunctional epoxy diluent and the flame retardant is 1: 0.25-0.45: 0.05-0.18: 0.08-0.13.

[0049] According to the present invention, the reaction conditions of the bisphenol epoxy resin, the novolac epoxy resin, the multifunctional epoxy diluent and the flame retardant include: a temperature of 120-200°C and a time of 2-8h; preferably, the reaction conditions of the bisphenol epoxy resin, the novolac epoxy resin, the multifunctional epoxy diluent and the flame retardant include: a temperature of 130-180°C and a time of 4-6h.

[0050] In a preferred embodiment of the present invention, the bisphenol epoxy resin, novolac epoxy resin and multifunctional epoxy diluent may be mixed and heated to a target temperature, and then a flame retardant is added for reaction. Preferably, the mixture is continuously stirred during the reaction of adding the flame retardant.

[0051] According to the present invention, after the reaction of the bisphenol epoxy resin, the novolac epoxy resin, the multifunctional epoxy diluent and the flame retardant is completed, a step of vacuum degassing the reaction product may be further included.

[0052] The vacuum degassing treatment is not particularly limited as long as it can achieve the purpose of eliminating bubbles. For example, the conditions of the vacuum degassing treatment may include: a vacuum degree of 0.1-0.3, a temperature of 40-60° C., and a time of 10-30 min.

[0053] According to the present invention, preferably, the reaction of the bisphenol epoxy resin, the novolac epoxy resin, the multifunctional epoxy diluent and the flame retardant is carried out under an inert atmosphere. The inert atmosphere can be implemented by introducing an inert gas, and the inert gas can use an inert atmosphere commonly used in the art, such as nitrogen, argon, etc.

[0054] In a preferred embodiment of the present invention, a mixture of bisphenol A epoxy resin, novolac epoxy resin and multifunctional epoxy diluent is heated to 130-180° C. under an inert atmosphere, and then a flame retardant is added to react for 4-6 hours. According to a third aspect of the present invention, a method for preparing a flame retardant epoxy resin material is provided, wherein the method includes the step of curing the components of the flame retardant epoxy resin composition.

[0055] According to the present invention, preferably, the curing conditions include: temperature of 120-140° C., time of 3-5 min; more preferably, the curing conditions include: temperature of 130-135° C., time of 4-5 min.

[0056] According to a fourth aspect of the present invention, a flame retardant epoxy resin material prepared by the method described in the third aspect of the present invention is provided.

[0057] The present invention is described in detail below by way of examples, but the present invention is not limited to the following examples.

[0058] In the following examples and comparative examples, unless otherwise specified, all reagents are commercially available.

[0059] Example 1

[0060] 1) Under nitrogen atmosphere, 50 g of bisphenol A epoxy resin (purchased from Nan Ya Epoxy Resin (Kunshan) Co., Ltd., model NPEL-127, the same below), 25 g of o-cresol epoxy resin (purchased from Nan Ya Epoxy Resin (Kunshan) Co., Ltd., model NPCN-704, the same below), and 10 g of sorbitol glycidyl ether (purchased from Anhui Xinyuan Technology Co., Ltd., model XY672, the same below) were mixed and heated to 130°C;

[0061] 2) adding 10 g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO, purchased from Jiangyin Hanfeng Technology Co., Ltd., the same below) to the resin in step 1), stirring at 130° C. for 4 h until the viscosity of the resin no longer changes to obtain a flame retardant epoxy resin;

[0062] 3) Under nitrogen atmosphere, 70 g of methylcyclopentanediamine (purchased from Henan Tianze Industrial Co., Ltd.), 10 g of diethylenetriamine (purchased from Sinopharm Chemical Reagent Co., Ltd., the same below), and 10 g of benzyldimethylamine (purchased from Sinopharm Chemical Reagent Co., Ltd., the same below) were mixed and heated to 120°C;

[0063] 4) 10 g of triisopropylphenyl phosphate (purchased from Sinopharm Chemical Reagent Co., Ltd., the same below) was added dropwise to the curing agent in step 3), reacted at 120° C. for 60 minutes, cooled to 70° C., and distilled under reduced pressure for 2 hours to obtain a flame retardant curing agent;

[0064] 5) The epoxy resin in step 2) and the flame retardant curing agent in step 4) were mixed uniformly in a mass ratio of 100:15, injected into a mold, and cured at 130° C. for 5 minutes to obtain a flame retardant epoxy resin material. The obtained flame retardant epoxy resin material was subjected to a performance test. The results are shown in Table 1.

[0065] Example 2

[0066] 1) Under nitrogen atmosphere, 45 g of bisphenol A epoxy resin, 35 g of bisphenol A novolac epoxy resin, 15 g of N,N,N,N,-tetraepoxypropyl-4,4-diaminodiphenylmethane (purchased from Shanghai Huayi Resin Co., Ltd., model AG-80, the same below), and 5 g of sorbitol glycidyl ether were mixed and heated to 130° C.;

[0067] 2) adding 15 g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to the resin in step 1), and stirring at 130° C. for 4 h until the viscosity of the resin no longer changes to obtain a flame retardant epoxy resin;

[0068] 3) Under nitrogen atmosphere, 55 g of 1,2-cyclohexanediamine, 25 g of triethylenetetramine, and 10 g of triethanolamine (purchased from Sinopharm Chemical Reagent Co., Ltd., the same below) were mixed and heated to 120°C;

[0069] 4) 15 g of triethyl phosphate was added dropwise to the curing agent in step 3), reacted at 120° C. for 60 minutes, cooled to 70° C., and distilled under reduced pressure for 3 hours to obtain a flame retardant curing agent;

[0070] 5) The epoxy resin in step 2) and the flame retardant curing agent in step 4) were mixed uniformly in a mass ratio of 100:20, injected into a mold, and cured at 130° C. for 5 minutes to obtain a flame retardant epoxy resin material. The obtained flame retardant epoxy resin material was subjected to a performance test. The results are shown in Table 1.

[0071] Example 3

[0072] 1) Under nitrogen atmosphere, 35 g of bisphenol A epoxy resin, 25 g of phenol novolac epoxy resin (purchased from Wuxi Resin Factory, model F-51, the same below), and 10 g of sorbitol glycidyl ether were mixed and heated to 130° C.;

[0073] 2) adding 16 g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to the resin in step 1), and stirring at 130° C. for 6 h until the viscosity of the resin no longer changes to obtain a flame retardant epoxy resin;

[0074] 3) Under nitrogen atmosphere, 45 g of o-diaminomethylcyclopentane (purchased from Sinopharm Chemical Reagent Co., Ltd., the same below), 10 g of 1,3-cyclohexanedimethylamine (purchased from Sinopharm Chemical Reagent Co., Ltd., the same below), 10 g of tetraethylenepentamine (purchased from Sinopharm Chemical Reagent Co., Ltd., the same below), and 9 g of o-hydroxybenzyldimethylamine (purchased from Sinopharm Chemical Reagent Co., Ltd., the same below) were mixed and heated to 120 °C;

[0075] 4) 15 g of triisobutyl phosphate (purchased from Sinopharm Chemical Reagent Co., Ltd., the same below) was added dropwise to the curing agent in step 3), reacted at 120° C. for 60 minutes, cooled to 70° C., and distilled under reduced pressure for 2 hours to obtain a flame retardant curing agent;

[0076] 5) The epoxy resin in step (2) and the flame retardant curing agent in step 4) were mixed uniformly in a mass ratio of 100:25, injected into a mold, and cured at 130° C. for 5 minutes to obtain a flame retardant epoxy resin material. The performance of the obtained flame retardant epoxy resin material was tested, and the results are shown in Table 1.

[0077] Example 4

[0078] 1) Under nitrogen atmosphere, 40 g of bisphenol A epoxy resin, 20 g of o-cresol epoxy resin, 20 g of phenol novolac epoxy resin, and 10 g of N,N,N,N,-tetracyclyl-4,4-diaminodiphenylmethane were mixed and heated to 130° C.;

[0079] 2) adding 18 g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to the resin in step 1), and stirring at 130° C. for 6 h until the viscosity of the resin no longer changes to obtain a flame retardant epoxy resin;

[0080] 3) Under nitrogen atmosphere, 45 g of methylcyclopentanediamine, 10 g of 1,3-cyclohexanedimethylamine, 30 g of triethylenetetramine, and 5 g of tetramethylethylenediamine (purchased from Sinopharm Chemical Reagent Co., Ltd., the same below) were mixed and heated to 120°C;

[0081] 4) 20 g of diphenyl isodecyl phosphate (purchased from Sinopharm Chemical Reagent Co., Ltd., the same below) was added dropwise to the curing agent in step 3), reacted at 120° C. for 60 minutes, cooled to 70° C., and distilled under reduced pressure for 2 hours to obtain a flame retardant curing agent;

[0082] 5) The epoxy resin in step 2) and the flame retardant curing agent in step 4) were mixed uniformly in a mass ratio of 100:18, injected into a mold, and cured at 130° C. for 5 minutes to obtain a flame retardant epoxy resin material. The obtained flame retardant epoxy resin material was subjected to a performance test. The results are shown in Table 1.

[0083] Example 5

[0084] 1) Under nitrogen atmosphere, 40 g of bisphenol A epoxy resin, 40 g of phenol novolac epoxy resin, 15 g of sorbitol glycidyl ether, and 10 g of N,N,N,N,-tetraepoxypropyl-4,4-diaminodiphenylmethane were mixed and heated to 130° C.;

[0085] 2) adding 25 g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to the resin in step 1), and stirring at 130° C. for 6 h until the viscosity of the resin no longer changes to obtain a flame retardant epoxy resin;

[0086] 3) Under nitrogen atmosphere, 55 g of isophorone diamine (purchased from Sinopharm Chemical Reagent Co., Ltd., the same below), 10 g of 4,4'-diaminodicyclohexylmethane (purchased from Sinopharm Chemical Reagent Co., Ltd., the same below), and 5 g of diethylenetriamine were mixed and heated to 120°C;

[0087] 4) 15 g of trimethyl phosphate (purchased from Sinopharm Chemical Reagent Co., Ltd., the same below) and 15 g of tert-butylbenzene diphenyl phosphate (purchased from Sinopharm Chemical Reagent Co., Ltd., the same below) were added dropwise to the curing agent in step 3), reacted at 120° C. for 60 minutes, cooled to 70° C., and distilled under reduced pressure for 2 hours to obtain a flame retardant curing agent;

[0088] 5) The epoxy resin in step 2) and the flame retardant curing agent in step 4) were mixed uniformly in a mass ratio of 100:15, injected into a mold, and cured at 130° C. for 5 minutes to obtain a flame retardant epoxy resin material. The obtained flame retardant epoxy resin material was subjected to a performance test. The results are shown in Table 1.

[0089] Comparative Example 1

[0090] 1) 40 g of bisphenol A epoxy resin, 40 g of phenol novolac epoxy resin, and 15 g of N,N,N,N,-tetraepoxypropyl-4,4-diaminodiphenylmethane were uniformly mixed to obtain resin A;

[0091] 2) 25g of tetraethylenepentamine (purchased from Sinopharm Chemical Reagent Co., Ltd., the same below) (polyethylene polyamine), 10g of 2-ethyl-4-methylimidazole, 20g of ammonium polyphosphate (purchased from Clariant Chemical, model Exolit AP 420, the same below), and 15g of pentaerythritol (purchased from Sinopharm Chemical Reagent Co., Ltd., the same below) were uniformly mixed with flame retardant curing agent B;

[0092] 3) The resin A in step 1) and the curing agent B in step 2) were mixed uniformly in a mass ratio of 100:100, injected into a mold, and cured at 130° C. for 5 minutes to obtain a flame retardant epoxy resin material. The performance of the obtained flame retardant epoxy resin material was tested, and the results are shown in Table 1.

[0093] Comparative Example 2

[0094] 1) Under nitrogen atmosphere, 50 g of bisphenol A epoxy resin, 25 g of o-cresol epoxy resin, and 10 g of sorbitol glycidyl ether were mixed and heated to 130° C.;

[0095] 2) adding 10 g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to the resin in step 1), stirring at 130° C. for 4 h until the viscosity of the resin no longer changes, cooling to 40° C., adding 10 g of triisopropylphenyl phosphate and stirring evenly to obtain a flame retardant epoxy resin;

[0096] 3) Under a nitrogen atmosphere, 70 g of methylcyclopentanediamine, 10 g of diethylenetriamine, and 10 g of benzyldimethylamine were mixed to obtain a flame retardant curing agent;

[0097] 4) The flame retardant epoxy resin in step 2) and the flame retardant curing agent in step 3) were mixed uniformly in a mass ratio of 100:12, injected into a mold, and cured at 130° C. for 5 minutes to obtain a flame retardant epoxy resin material. The obtained flame retardant epoxy resin material was tested for performance, and the results are shown in Table 1.

[0098] Comparative Example 3

[0099] 1) Under nitrogen atmosphere, 50 g of bisphenol A epoxy resin, 25 g of o-cresol epoxy resin, and 10 g of sorbitol glycidyl ether were mixed and heated to 100° C.;

[0100] 2) adding 10 g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to the resin in step 1), stirring at 100° C. for 1 h until the 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is completely dissolved to obtain a flame retardant epoxy resin;

[0101] 3) Under nitrogen atmosphere, 70 g of methylcyclopentanediamine, 10 g of diethylenetriamine and 10 g of benzyldimethylamine were mixed and heated to 120° C.;

[0102] 4) adding 10 g of triisopropylphenyl phosphate dropwise to the curing agent in step 3), reacting at 120° C. for 60 minutes, cooling to 70° C., and performing vacuum distillation for 2 hours to obtain a flame retardant curing agent;

[0103] 5) The epoxy resin in step 2) and the flame retardant curing agent in step 4) were mixed uniformly in a mass ratio of 100:15, injected into a mold, and cured at 130° C. for 5 minutes to obtain a flame retardant epoxy resin material. The obtained flame retardant epoxy resin material was subjected to a performance test. The results are shown in Table 1.

[0104] Comparative Example 4

[0105] 1) Under nitrogen atmosphere, 75 g of bisphenol A epoxy resin and 10 g of sorbitol glycidyl ether were mixed and heated to 130° C.;

[0106] 2) adding 10 g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to the resin in step 1), and stirring at 130° C. for 4 h until the viscosity of the resin no longer changes to obtain a flame retardant epoxy resin;

[0107] 3) Under nitrogen atmosphere, 70 g of methylcyclopentanediamine, 10 g of diethylenetriamine and 10 g of benzyldimethylamine were mixed and heated to 120° C.;

[0108] 4) adding 10 g of triisopropylphenyl phosphate dropwise to the curing agent in step 3), reacting at 120° C. for 60 minutes, cooling to 70° C., and performing vacuum distillation for 2 hours to obtain a flame retardant curing agent;

[0109] 5) The epoxy resin in step 2) and the flame retardant curing agent in step 4) were mixed uniformly in a mass ratio of 100:15, injected into a mold, and cured at 130° C. for 5 minutes to obtain a flame retardant epoxy resin material. The obtained flame retardant epoxy resin material was subjected to a performance test. The results are shown in Table 1.

[0110] Comparative Example 5

[0111] 1) Under nitrogen atmosphere, 75 g of o-cresol epoxy resin and 10 g of sorbitol glycidyl ether were mixed and heated to 130° C.;

[0112] 2) adding 10 g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to the resin in step 1), and stirring at 130° C. for 4 h until the viscosity of the resin no longer changes to obtain a flame retardant epoxy resin;

[0113] 3) Under nitrogen atmosphere, 70 g of methylcyclopentanediamine, 10 g of diethylenetriamine and 10 g of benzyldimethylamine were mixed and heated to 120° C.;

[0114] 4) adding 10 g of triisopropylphenyl phosphate dropwise to the curing agent in step 3), reacting at 120° C. for 60 minutes, cooling to 70° C., and performing vacuum distillation for 2 hours to obtain a flame retardant curing agent;

[0115] 5) The epoxy resin in step 2) and the flame retardant curing agent in step 4) were mixed uniformly in a mass ratio of 100:15, injected into a mold, and cured at 130° C. for 5 minutes to obtain a flame retardant epoxy resin material. The obtained flame retardant epoxy resin material was subjected to a performance test. The results are shown in Table 1.

[0116] Comparative Example 6

[0117] 1) Under nitrogen atmosphere, 50 g of bisphenol A epoxy resin, 25 g of o-cresol epoxy resin, and 10 g of sorbitol glycidyl ether were mixed and heated to 130° C.;

[0118] 2) adding 10 g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to the resin in step 1), and stirring at 130° C. for 4 h until the viscosity of the resin no longer changes to obtain a flame retardant epoxy resin;

[0119] 3) Under nitrogen atmosphere, 80 g of diethylenetriamine and 10 g of benzyldimethylamine were mixed and heated to 120°C;

[0120] 4) adding 10 g of triisopropylphenyl phosphate dropwise to the curing agent in step 3), reacting at 120° C. for 60 minutes, cooling to 70° C., and performing vacuum distillation for 2 hours to obtain a flame retardant curing agent;

[0121] 5) The epoxy resin in step 2) and the flame retardant curing agent in step 4) were mixed uniformly in a mass ratio of 100:15, injected into a mold, and cured at 130° C. for 5 minutes to obtain a flame retardant epoxy resin material. The obtained flame retardant epoxy resin material was subjected to a performance test. The results are shown in Table 1.

[0122] Comparative Example 7

[0123] 1) Under nitrogen atmosphere, 50 g of bisphenol A epoxy resin, 25 g of o-cresol epoxy resin, and 10 g of sorbitol glycidyl ether were mixed and heated to 130° C.;

[0124] 2) adding 10 g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to the resin in step 1), and stirring at 130° C. for 4 h until the viscosity of the resin no longer changes to obtain a flame retardant epoxy resin;

[0125] 3) Under nitrogen atmosphere, heat 90 g of methylcyclopentanediamine to 120° C.;

[0126] 4) adding 10 g of triisopropylphenyl phosphate dropwise to the curing agent in step 3), reacting at 120° C. for 60 minutes, cooling to 70° C., and performing vacuum distillation for 2 hours to obtain a flame retardant curing agent;

[0127] 5) The epoxy resin in step 2) and the flame retardant curing agent in step 4) were mixed uniformly in a mass ratio of 100:15, injected into a mold, and cured at 130° C. for 5 minutes to obtain a flame retardant epoxy resin material. The obtained flame retardant epoxy resin material was subjected to a performance test. The results are shown in Table 1.

[0128] Comparative Example 8

[0129] 1) Under nitrogen atmosphere, 50 g of bisphenol A epoxy resin, 25 g of o-cresol epoxy resin, and 10 g of sorbitol glycidyl ether were mixed and heated to 130° C.;

[0130] 2) adding 10 g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to the resin in step 1), and stirring at 130° C. for 4 h until the viscosity of the resin no longer changes to obtain a flame retardant epoxy resin;

[0131] 3) Under a nitrogen atmosphere, 70 g of methylcyclopentanediamine, 80 g of diethylenetriamine, and 10 g of benzyldimethylamine were mixed to obtain a curing agent;

[0132] 4) The flame retardant epoxy resin in step 2) and the flame retardant curing agent in step 3) were mixed uniformly in a mass ratio of 100:15, injected into a mold, and cured at 130° C. for 5 minutes to obtain a flame retardant epoxy resin material. The obtained flame retardant epoxy resin material was subjected to a performance test. The results are shown in Table 1.

[0133] Test Example 1

[0134] 1. Resin viscosity test

[0135] The flame retardant epoxy resin was tested for viscosity every 5 minutes. The testing instrument was a Brookfield viscometer (purchased from AMETEK Trading (Shanghai) Co., Ltd., model DV-Ⅱ), the standard was ASTM D2983-2022, and the test results are shown in Table 1.

[0136] 2. Mechanical properties test

[0137] Preparation of resin casting: a certain amount of resin and curing agent were mixed evenly according to the ratio, and after vacuum degassing, they were injected into the tensile and bending specimen molds, and cured at 100°C for 30 minutes and 120°C for 30 minutes, and then cooled to room temperature. Then the test was carried out on a universal testing machine (purchased from Instron (Shanghai) Testing Equipment Trading Co., Ltd., model INSTRON3382).

[0138] The tensile properties were tested according to ISO 527, and the flexural properties were tested according to ISO 178. The test results are shown in Table 1.

[0139] 3. Determination of interlaminar shear strength

[0140] Preparation of composite materials: Mix a certain amount of resin and curing agent according to the ratio, and after vacuum degassing, inject it into the mold with pre-laid carbon fiber through RTM process. The mold is heated to 130℃ and kept warm for 5 minutes. After cooling to room temperature, take out and cut samples according to ISO 14130:1997 standard, cut 6-8 specimens, and then test them on a universal testing machine.

[0141] The interlaminar shear strength was tested in accordance with ISO 14130:1997. The test results are shown in Table 1.

[0142] 3. Tg test

[0143] Preparation of resin casting: A certain amount of resin and curing agent were mixed evenly according to the ratio, and after vacuum degassing, they were injected into the tensile and bending specimen molds, and cured at 100°C for 30 minutes and 120°C for 30 minutes, and then cooled to room temperature. Samples were taken for Tg testing in a differential scanning calorimeter (purchased from TA Instruments, USA, model DSCQ20).

[0144] The test results are shown in Table 1 according to the DSC midpoint method.

[0145] 4. Flame retardant performance test of flame retardant epoxy resin materials

[0146] Tested according to UL 94 vertical burning standard, the test results are shown in Table 1.

[0147] 5. Gel time test

[0148] Equipment: Microcomputer electric heating plate: customized by the manufacturer, model BEST-946. Mix the resin and curing agent according to the ratio, take 1-2g of the mixed liquid and drop it on the hot plate at a certain temperature, start timing, until the resin mixed liquid changes from a flowing liquid state to a state that can be drawn, the time required is the hot plate gel time.

[0149] Table 1

[0150]

[0151] As shown in Table 1, the present invention reasonably selects and matches the flame retardant epoxy resin and the flame retardant curing agent. By comparing Example 1 with Comparative Example 5, it can be seen that the phenolic epoxy resin is used as the main body, and the flame retardant modified epoxy resin is solid at room temperature, which affects the normal process use.

[0152] By comparing Example 1 with Comparative Example 3, it can be seen that the flame retardant effect of the epoxy resin to which the flame retardant is physically added does not reach the UL94 V0 level.

[0153] By comparing Example 1 with Comparative Example 4, it can be seen that the flame retardant effect of using only bisphenol A epoxy resin cannot reach the UL94V0 level.

[0154] By comparing Example 1 with Comparative Example 6, it can be seen that without using alicyclic amine curing agent, although the curing speed of the formulation system is faster, the heat resistance and mechanical properties of the resin are significantly reduced.

[0155] By comparing Example 1 with Comparative Example 7, it can be seen that without using polyethylene polyamine, although the flame retardant performance of the formula meets the standard, the curing speed is slow and the rapid curing effect cannot be achieved.

[0156] By comparing Example 1 with Comparative Example 8, it can be seen that the lack of the modified flame retardant curing agent causes the flame retardant performance of the entire formulation system to fail to meet the standard.

[0157] 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 flame retardant curing agent, characterized in that: The flame retardant curing agent contains a reaction product of alicyclic amine, polyethylene polyamine, tertiary amine and phosphate.

2. The flame retardant curing agent according to claim 1, wherein The alicyclic amine is selected from at least one of isophoronediamine, methylcyclopentanediamine, o-diaminomethylcyclopentane, 1,3-cyclohexanedimethylamine, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, 1,2-cyclohexanediamine or 4,4'-diaminodicyclohexylmethane, menthanediamine and N-aminoethylpiperazine, preferably at least one of isophoronediamine, methylcyclopentanediamine, o-diaminomethylcyclopentane and 1,3-cyclohexanedimethylamine; Preferably, the polyethylene polyamine is selected from at least one of diethylenetriamine, triethylenetetramine, tetraethylenepentamine and divinylpropylamine, preferably at least one of diethylenetriamine, triethylenetetramine and tetraethylenepentamine; Preferably, the tertiary amine is selected from at least one of tetramethylethylenediamine, tetramethylhexanediamine, dimethylethanolamine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, triethanolamine, o-hydroxybenzyldimethylamine and triethylamine, preferably at least one of tetramethylhexanediamine, benzyldimethylamine, triethanolamine and o-hydroxybenzyldimethylamine; Preferably, the phosphate is selected from at least one of triethyl phosphate, trimethyl phosphate, triphenyl phosphate, tolylene diphenyl phosphate, triisobutyl phosphate, diphenyl isodecyl phosphate, triisopropylphenyl phosphate, tributoxyethyl phosphate, tert-butylbenzene diphenyl phosphate and tri(xylene) phosphate, preferably at least one of triethyl phosphate, trimethyl phosphate, triisobutyl phosphate, diphenyl isodecyl phosphate, triisopropylphenyl phosphate and tert-butylbenzene diphenyl phosphate.

3. The composition according to claim 1, wherein The molar ratio of the alicyclic amine, polyethylene polyamine, tertiary amine and phosphate is 1: 0.2-0.5: 0.1-0.3: 0.4-0.7; preferably 1: 0.25-0.45: 0.12-0.25: 0.45-0.

65.

4. The composition according to any one of claims 1 to 3, wherein The reaction conditions of the alicyclic amine, polyethylene polyamine, tertiary amine and phosphate ester include: temperature of 100-130° C. and time of 2-4 hours; Preferably, the reaction conditions of the alicyclic amine, polyethylene polyamine, tertiary amine and phosphate include: temperature of 115-125° C. and time of 150-200 min.

5. A flame retardant epoxy resin composition, characterized in that: The composition contains a flame retardant epoxy resin and the flame retardant curing agent described in any one of claims 1 to 4, wherein the flame retardant epoxy resin contains a reaction product of a bisphenol epoxy resin, a phenolic epoxy resin, a multifunctional epoxy diluent and a flame retardant.

6. The composition according to claim 5, wherein The flame retardant epoxy resin composition contains 60-98 wt % of a flame retardant epoxy resin and 10-25 wt % of a flame retardant curing agent; Preferably, the flame retardant epoxy resin composition contains 80-95 wt % of the flame retardant epoxy resin and 15-20 wt % of the flame retardant curing agent.

7. The composition according to claim 5, wherein The bisphenol epoxy resin is at least one of bisphenol A epoxy resin, bisphenol F epoxy resin and hydrogenated bisphenol A epoxy resin, preferably bisphenol A epoxy resin.

8. The composition according to any one of claim 5, wherein The novolac epoxy resin is selected from at least one of phenol-type novolac epoxy resin, o-cresol novolac epoxy resin and bisphenol A novolac epoxy resin, preferably at least one of phenol-type novolac epoxy resin and o-cresol novolac epoxy resin.

9. The composition according to any one of claim 5, wherein The multifunctional epoxy diluent is selected from at least one of N,N,N,N,-tetraepoxypropyl-4,4-diaminodiphenylmethane, sorbitol glycidyl ether, cyclohexanediamine tetrafunctional epoxy resin and trimethylolpropane triglycidyl ether, preferably at least one of N,N,N,N,-tetraepoxypropyl-4,4-diaminodiphenylmethane and sorbitol glycidyl ether.

10. The composition according to any one of claim 5, wherein The flame retardant is selected from at least one of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10-(2,5-dihydroxyphenyl)-10-hydrogen-9-oxa-10-phosphaphenanthrene-10-oxide and [(6-oxy-(6H)-dibenzo-(CE)(1,2)-oxaphosphahexane-6-one)methyl]-succinic acid, preferably 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide.

11. The composition according to any one of claims 5, wherein The weight ratio of the bisphenol epoxy resin, the novolac epoxy resin, the multifunctional epoxy diluent and the flame retardant is 1:0.2-0.5:0.03-0.2:0.05-0.15, preferably 1:0.25-0.45:0.05-0.18:0.08-0.

13.

12. The composition according to any one of claims 5, wherein The reaction conditions of the bisphenol epoxy resin, the novolac epoxy resin, the multifunctional epoxy diluent and the flame retardant include: a temperature of 120-200° C. and a time of 2-8 hours; Preferably, the reaction conditions of the bisphenol epoxy resin, the novolac epoxy resin, the multifunctional epoxy diluent and the flame retardant include: a temperature of 130-180° C. and a reaction time of 4-6 hours.

13. A method for preparing a flame retardant epoxy resin material, characterized in that: The method comprises the step of curing the components of the flame retardant epoxy resin composition according to any one of claims 5 to 12.

14. The method according to claim 13, wherein the curing conditions include: The temperature is 120-140℃ and the time is 3-5min; Preferably, the curing conditions include: a temperature of 130-135° C. and a time of 4-5 min.

15. A flame retardant epoxy resin material prepared by the method according to claim 13 or 14.

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