An acrylic epoxy resin modified cardanol aldehyde amine epoxy curing agent, a preparation method and application thereof

Abstract

The present application relates to the technical field of epoxy coating, and particularly relates to an acrylic epoxy resin modified cashew phenolic amine epoxy curing agent, a preparation method and application thereof.The present application provides an acrylic epoxy resin modified cashew phenolic amine epoxy curing agent, and preparation raw materials include the following components according to mass fraction: cashew phenolic amine 60-80 parts, phosphite amino derivative 14-24 parts, acrylic epoxy resin 3-8 parts and bis-epoxy diluent 3-8 parts.The acrylic epoxy resin modified cashew phenolic amine epoxy curing agent has strong adhesion, and excellent impact resistance and flexibility.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of epoxy coating, in particular to an acrylic epoxy resin modified cardanol aldehyde amine epoxy curing agent and a preparation method and application thereof. BACKGROUND

[0002] Cardanol modified amine epoxy curing agent refers to a phenolic aldehyde amine curing agent prepared by Mannich reaction of cardanol instead of phenol and formaldehyde and polyamine, containing aliphatic amino group, weakly acidic phenolic aldehyde group and C 15 Unsaturated long side chain benzene ring.

[0003] Cardanol is a natural biomass phenol with unique long-chain alkanes extracted from natural cashew nut shell oil, which is a green and environmentally friendly industrial raw material. The long-chain substituted modified amine curing agent synthesized from cardanol has the advantages of fatty amine curing agent, low molecular weight polyamide curing agent and general phenolic aldehyde amine curing agent. The cardanol aldehyde amine curing agent has good adhesion to the substrate of tinplate when applied in epoxy paint, but the adhesion to cold rolled steel is poor. Therefore, it has broad market prospects to prepare a cardanol aldehyde amine curing agent with high adhesion to cold rolled steel, and its impact resistance and flexibility reach the same level as commercially available products. SUMMARY

[0004] Therefore, the purpose of the present application is to provide an acrylic epoxy resin modified cardanol aldehyde amine epoxy curing agent and a preparation method and application thereof. The acrylic epoxy resin modified cardanol aldehyde amine epoxy curing agent has strong adhesion, excellent impact resistance and flexibility.

[0005] In order to achieve the above-mentioned purpose of the application, the present application provides the following technical scheme:

[0006] The present application provides an acrylic epoxy resin modified cardanol aldehyde amine epoxy curing agent, the preparation raw materials including the following components in mass fraction: cardanol aldehyde amine 60-80 parts, phosphite amino derivative 14-24 parts, acrylic epoxy resin 3-8 parts and bis epoxy diluent 3-8 parts.

[0007] Preferably, the preparation method of the cardanol aldehyde amine includes the following steps:

[0008] In a protective atmosphere, cardanol, first aliphatic amine and first polyformaldehyde are mixed to carry out first Mannich reaction to obtain a first product system;

[0009] The first product system, second aliphatic amine and second polyformaldehyde are mixed to carry out second Mannich reaction to obtain the cardanol aldehyde amine.

[0010] Preferably, the molar ratio of the cardanol, the first fatty amine and the formaldehyde monomer in the first paraformaldehyde is 1:(0.6-0.8):(0.8-0.9);

[0011] the molar ratio of the cardanol, the second fatty amine and the formaldehyde monomer in the second paraformaldehyde is 1:(0.4-0.6):(0.6-0.8);

[0012] the first fatty amine comprises one or more of N,N-diethyl-1,3-propanediamine, N,N-dipropyl-1,3-propanediamine and N,N-dibutyl-1,3-propanediamine;

[0013] the second fatty amine comprises one or more of ethylenediamine, diethylenetriamine, triethylenetetramine and tetraethylenepentamine.

[0014] Preferably, the temperature of the first Mannich reaction is 80-120℃ and the time is 2-6h;

[0015] the temperature of the second Mannich reaction is 80-120℃ and the time is 2-4h.

[0016] Preferably, the preparation method of the phosphite amino derivative comprises the following steps:

[0017] In a protective atmosphere, after the diethylenetriamine is added to the paraformaldehyde in batches, an amine methylation reaction is carried out, diethyl phosphite is added, a substitution reaction is carried out, and the phosphite amino derivative is obtained.

[0018] Preferably, the molar ratio of the diethylenetriamine, the formaldehyde monomer in the paraformaldehyde and the diethyl phosphite is 2:(1-1.3):1;

[0019] the temperature of the amine methylation reaction is 50-60℃ and the holding time is 4-8h;

[0020] the temperature of the substitution reaction is 60-80℃ and the holding time is 10-14h.

[0021] Preferably, the preparation method of the acrylic acid epoxy resin comprises the following steps:

[0022] In a protective atmosphere, after the epoxy resin, the first polymerization inhibitor and the catalyst are mixed, a mixed solution of acrylic acid and the second polymerization inhibitor is added at a temperature of 80-120℃, an addition reaction is carried out, and the acrylic acid epoxy resin is obtained;

[0023] the temperature of the addition reaction is 100-120℃ and the holding time is 2.5-3.5h.

[0024] Preferably, the said diepoxy diluent includes one or more of 1,6-hexanediol diglycidyl ether, 1,4-butanediol diglycidyl ether, ethylene glycol diglycidyl ether, 1,4-cyclohexanedimethanol diglycidyl ether, diethylene glycol diglycidyl ether, dipropylene glycol diglycidyl ether and triethylene glycol diglycidyl ether.

[0025] The present application also provides a preparation method of the cashew phenolic aldehyde amine epoxy curing agent modified by the acrylic epoxy resin, including the following steps:

[0026] In a protective atmosphere, after mixing the cashew phenolic aldehyde amine and the phosphite amino derivative, the mixed solution of the acrylic epoxy resin and the diepoxy diluent is added to perform modification, so as to obtain the cashew phenolic aldehyde amine epoxy curing agent modified by the acrylic epoxy resin.

[0027] The present application also provides an application of the cashew phenolic aldehyde amine epoxy curing agent modified by the acrylic epoxy resin or the cashew phenolic aldehyde amine epoxy curing agent modified by the acrylic epoxy resin prepared by the preparation method in the field of coating.

[0028] The present application provides a cashew phenolic aldehyde amine epoxy curing agent modified by an acrylic epoxy resin, and preparation raw materials include the following components in mass fraction: 60-80 parts of cashew phenolic aldehyde amine, 14-24 parts of phosphite amino derivative, 3-8 parts of acrylic epoxy resin and 3-8 parts of diepoxy diluent. The phosphite group in the phosphite amino derivative in the preparation raw materials of the cashew phenolic aldehyde amine epoxy curing agent modified by the acrylic epoxy resin can improve the adhesion to the base material, improve the adhesion of the modified cashew phenolic aldehyde amine to the epoxy resin curing product, especially the adhesion to the iron base material and the cold-rolled steel material; meanwhile, the cashew phenolic aldehyde amine and the phosphite amino derivative can be connected to form a macromolecule through the acrylic epoxy resin and the diepoxy diluent, and the impact resistance, the flexibility and the stability are good, and the adverse phenomena such as delamination and turbidity after long-term storage do not occur, and the acrylic epoxy resin can further improve the adhesion of the cured coating. DETAILED DESCRIPTION

[0029] The present application provides a cashew phenolic aldehyde amine epoxy curing agent modified by an acrylic epoxy resin, and preparation raw materials include the following components in mass fraction: 60-80 parts of cashew phenolic aldehyde amine, 14-24 parts of phosphite amino derivative, 3-8 parts of acrylic epoxy resin and 3-8 parts of diepoxy diluent.

[0030] In the present application, all the preparation raw materials are commercially available products known to those skilled in the art without special instructions.

[0031] The preparation raw material of the acrylic epoxy resin modified cashew phenolic amine epoxy curing agent according to the application comprises 60-80 parts of cashew phenolic amine, preferably 65-75 parts. In the embodiment of the application, the cashew phenolic amine is 60 parts, 65 parts, 70 parts or 80 parts.

[0032] In the application, the preparation method of the cashew phenolic amine preferably comprises the following steps:

[0033] Under a protective atmosphere, cashew phenol, a first fatty amine and a first polyformaldehyde are mixed to perform a first Mannich reaction to obtain a first product system;

[0034] The first product system, a second fatty amine and a second polyformaldehyde are mixed to perform a second Mannich reaction to obtain the cashew phenolic amine.

[0035] In the application, cashew phenol, a first fatty amine and a first polyformaldehyde are mixed to perform a first Mannich reaction to obtain a first product system under a protective atmosphere.

[0036] In the application, the protective atmosphere is preferably a nitrogen atmosphere.

[0037] In the application, the purity of the cashew phenol is preferably 85-92%.

[0038] In the application, the molar ratio of the cashew phenol, the first fatty amine and the formaldehyde monomer in the first polyformaldehyde is preferably 1:(0.6-0.8):(0.8-0.9), more preferably 1:(0.65-0.75):(0.83-0.86).

[0039] In the application, the first fatty amine comprises one or more of N,N-diethyl-1,3-propanediamine, N,N-dipropyl-1,3-propanediamine and N,N-dibutyl-1,3-propanediamine. When the first fatty amine is two or more of the above specific choices, the application does not have any special limitation on the ratio of the above specific substances, and the mixing can be performed in any ratio.

[0040] In the application, the mixing preferably comprises, after the first mixing of the cashew phenol and the first fatty amine, adding the first polyformaldehyde in batches. In the application, the temperature of the first mixing is preferably 50-80°C, more preferably 60-70°C; the time of the first mixing is preferably 0.3-0.7h, more preferably 0.5h. In the application, the temperature of adding the first polyformaldehyde is preferably 70-80°C, more preferably 73-78°C.

[0041] In the application, the temperature of the first Mannich reaction is preferably 80-120°C, more preferably 90-110°C; the time is preferably 2-6h, more preferably 4-5h.

[0042] After obtaining the first product system, the first product system, a second fatty amine and a second paraformaldehyde are mixed to perform a second Mannich reaction to obtain the cardanol aldehyde amine.

[0043] In the present application, the molar ratio of the cardanol, the second fatty amine and the formaldehyde monomer in the second paraformaldehyde is preferably 1:(0.4-0.6):(0.6-0.8), and more preferably 1:(0.45-0.55):(0.65-0.75).

[0044] In the present application, the second fatty amine preferably includes one or two of ethylenediamine, diethylenetriamine, triethylenetetramine and tetraethylenepentamine. When the second fatty amine is two of the above specific choices, the present application does not have any special limitation on the ratio of the above specific substances, and mixing in any ratio is acceptable.

[0045] In the present application, the mixing is preferably adding the second fatty amine to the first product system under the condition of 80℃, stirring, and adding the second paraformaldehyde in batches. The present application does not have any special limitation on the adding method of the second fatty amine, and adding in a manner known to those skilled in the art is acceptable. In the present application, the stirring time is preferably 0.3-0.7h, and more preferably 0.5h. In the present application, the temperature for adding the second paraformaldehyde in batches is preferably 70-80℃, and more preferably 73-76℃; and the second paraformaldehyde is preferably added in two batches.

[0046] In the present application, the temperature of the second Mannich reaction is preferably 80-120℃, and more preferably 0-110℃; and the time is preferably 2-4h, and more preferably 2.5-3.5h.

[0047] After the completion of the second Mannich reaction, the present application further preferably includes a process of removing light components. In the present application, the process of removing light components is preferably performed under vacuum conditions, and the vacuum degree of the vacuum conditions is preferably 2-5kPa, and more preferably 3-4kPa; the temperature for removing light components is preferably 80-120℃, and more preferably 90-110℃; and the time for removing light components is preferably 1h.

[0048] Based on the mass fraction of the cardanol aldehyde amine, the preparation raw material of the acrylic epoxy resin modified cardanol aldehyde amine epoxy curing agent in the present application includes 14-24 parts of phosphite amino derivatives, and preferably 16-20 parts.

[0049] In the present application, the preparation method of the phosphite amino derivatives preferably includes the following steps:

[0050] The amine methylation reaction is carried out after the batched addition of paraformaldehyde to diethylenetriamine in a protective atmosphere, and the substitution reaction is carried out after the addition of diethyl phosphite, so that the phosphite amino derivative is obtained.

[0051] In the present application, the protective atmosphere is preferably a nitrogen atmosphere.

[0052] In the present application, the number of times of batched addition of paraformaldehyde is preferably 5-7, and more preferably 6. In the present application, the batched addition of paraformaldehyde is preferably carried out under stirring, and the present application does not have any special limitation on the process of stirring, which can be carried out using a process well known to those skilled in the art.

[0053] In the present application, the molar ratio of diethylenetriamine to formaldehyde monomer in paraformaldehyde is preferably 2: (1-1.3), and more preferably 2:1.1. In the embodiments of the present application, the molar ratio of diethylenetriamine to paraformaldehyde can be 2:1.1.

[0054] In the present application, the temperature of the amine methylation reaction is preferably 50-60°C, and more preferably 53-56°C; and the holding time is preferably 4-8h, and more preferably 5-6h.

[0055] After the completion of the amine methylation reaction, the present application further preferably includes removing the water and part of the residual diethylenetriamine generated after the completion of the amine methylation reaction. In the present application, the temperature for removing the water and part of the diethylenetriamine generated after the completion of the amine methylation reaction is preferably 75-85°C, and more preferably 80°C; and the way for removing the water and part of the diethylenetriamine generated after the completion of the amine methylation reaction is preferably vacuumizing, and the vacuum degree obtained after the vacuumizing is preferably 1-2kPa.

[0056] In the present application, the molar ratio of diethylenetriamine to diethyl phosphite is preferably 2:1.

[0057] The present application does not have any special limitation on the process of adding diethyl phosphite, which can be carried out using a process well known to those skilled in the art.

[0058] In the present application, the temperature of the substitution reaction is preferably 60-80°C, and more preferably 65-75°C; and the time of the substitution reaction is preferably 10-14h, and more preferably 12h.

[0059] After the completion of the substitution reaction, the present application further preferably includes a process of removing the remaining diethylenetriamine; and the temperature of the process of removing the remaining diethylenetriamine is preferably 120°C, and the vacuum degree is preferably 2-3kPa.

[0060] The preparation raw material of the acrylic epoxy resin modified cashew phenolic amine epoxy curing agent in the application includes 3-8 parts of acrylic epoxy resin, preferably 4-6 parts, based on the mass fraction of cashew phenolic amine.

[0061] In the application, the preparation method of the acrylic epoxy resin includes the following steps:

[0062] In a protective atmosphere, the mixture of the epoxy resin, the first polymerization inhibitor and the catalyst is added with the mixture of acrylic acid and the second polymerization inhibitor at a temperature of 80-120 DEG C to carry out addition reaction, so as to obtain the acrylic epoxy resin; the temperature of the addition reaction is 100-120 DEG C, and the holding time is 3h.

[0063] In the application, the protective atmosphere is preferably nitrogen atmosphere.

[0064] In the application, the epoxy resin is preferably bisphenol A type epoxy resin E51; in the application, the first polymerization inhibitor preferably includes one or more of hydroquinone, p-hydroxyanisole, 2,6-di-tert-butyl-p-cresol, 2,5-di-tert-butyl-hydroquinone and 2-tert-butyl-hydroquinone; when the first polymerization inhibitor is two or more of the above-mentioned specific choices, the application does not have any special limitation on the ratio of the above-mentioned specific substances, and the mixture can be mixed in any ratio.

[0065] In the application, the mass ratio of the epoxy resin, the first polymerization inhibitor and the catalyst is preferably 1:(0.02-0.05):(0.005-0.01), more preferably 1:0.04:0.008.

[0066] In the application, the mixing is preferably carried out under stirring, and the application does not have any special limitation on the stirring process, which can be carried out in the conditions well known to those skilled in the art.

[0067] After the mixing, the application also preferably includes stirring and heating, and the application does not have any special limitation on the stirring and heating process, which can be carried out in the process well known to those skilled in the art and can ensure heating to the required temperature of the mixture of acrylic acid and the second polymerization inhibitor.

[0068] In the present invention, the temperature of the mixture of acrylic acid and the second polymerization inhibitor is preferably 80-120°C, more preferably 90-110°C. The mixture of acrylic acid and the second polymerization inhibitor is preferably added dropwise. The present invention does not specify any specific requirements for the dropwise addition process, and any process familiar to those skilled in the art can be used. In the present invention, the mass concentration of acrylic acid in the mixture of acrylic acid and the second polymerization inhibitor is preferably 95-98%, and the mass concentration of the second polymerization inhibitor in the mixture of acrylic acid and the second polymerization inhibitor is preferably 2-5%. In the present invention, the molar ratio of epoxy groups in the epoxy resin to acrylic acid is preferably 2:(0.98-1.02), more preferably 2:1.

[0069] In the present invention, the temperature of the addition reaction is preferably 100-120° C., more preferably 105-115° C.; the holding time is preferably 2.5-3.5 h, more preferably 3 h.

[0070] Based on the mass fraction of cardanol aldehyde amine, the raw materials for preparing the acrylic epoxy resin modified cardanol aldehyde amine epoxy curing agent of the present invention include 3 to 8 parts of diepoxy diluent, preferably 4 to 7 parts.

[0071] In the present invention, the diepoxy diluent preferably includes one or more of 1,6-hexanediol diglycidyl ether, 1,4-butanediol diglycidyl ether, ethylene glycol diglycidyl ether, 1,4-cyclohexanedimethanol diglycidyl ether, diethylene glycol diglycidyl ether, dipropylene glycol diglycidyl ether and triethylene glycol diglycidyl ether. When the diepoxy diluent is two or more of the above-mentioned specific selections, the present invention has no special limitation on the ratio of the above-mentioned specific substances, and they can be mixed in any ratio.

[0072] The present invention also provides a method for preparing the acrylic epoxy resin modified cardanol aldehyde amine epoxy curing agent described in the above technical solution, comprising the following steps:

[0073] In a protective atmosphere, after mixing the cardanol aldehyde amine and the phosphite amino derivative, a mixed solution of acrylic epoxy resin and diepoxy diluent is added to carry out modification to obtain the acrylic epoxy resin modified cardanol aldehyde amine epoxy curing agent.

[0074] In the present invention, the protective atmosphere is preferably nitrogen.

[0075] In the present invention, the mixing temperature is preferably 60-80°C, more preferably 65-75°C; the mixing time is preferably 1.5-2.5 hours, more preferably 2 hours. In the present invention, the mixing is preferably carried out under stirring conditions. The present invention does not have any particular limitation on the stirring process, and the stirring process can be carried out using a process well known to those skilled in the art.

[0076] In the present application, the adding mode of the mixture of the acrylic epoxy resin and the diluent of bis-epoxy is preferably uniform dropping, and the dropping time is preferably 0.5-1.5h, more preferably 1h.

[0077] In the present application, the modification temperature is preferably 70-90℃, more preferably 75-85℃, and the holding time is preferably 2-6h, more preferably 3-5h.

[0078] The present application also provides the application of the acrylic epoxy resin modified cardanol aldehyde amine epoxy curing agent in the coating field, which is prepared by the technical scheme or the preparation method.

[0079] The technical scheme of the present application will be described clearly and completely in combination with the embodiments in the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by the person skilled in the art without creative labor are within the protection scope of the present application.

[0080] Preparation method of phosphite amino derivative:

[0081] Under the nitrogen atmosphere, 2mol of diethylene triamine is put into a reaction kettle, a stirrer is started, 1.1mol (molar amount of formaldehyde monomer) of polyformaldehyde is added in 6 times, 60℃ holding for 6h, the temperature is increased to 80℃, the vacuum is extracted to 1-2kPa, the water generated by the amine methylation reaction and part of the unreacted diethylene triamine are removed, 1mol of diethyl phosphite is added, 60℃ holding for 12h, the vacuum is extracted to negative pressure 2-3kPa, the temperature is increased to 120℃ holding for 1h to remove the remaining unreacted diethylene triamine, and the phosphite amino derivative is obtained.

[0082] Preparation method of acrylic epoxy resin:

[0083] Under the nitrogen atmosphere, 380g of bisphenol A type epoxy resin E51, 15g of polymerization inhibitor (the type is p-hydroxyanisole) and 3.1g of catalyst (the type is ethyl triphenyl phosphonium iodide) are put into a reaction kettle, stirring and increasing the temperature to 80℃, then 72g of the mixture of acrylic acid and polymerization inhibitor (the type of polymerization inhibitor in the mixture is 2,6-di-tert-butyl-p-cresol, the mass concentration of acrylic acid is 96%, and the mass concentration of polymerization inhibitor is 4%) is added dropwise at 80-100℃, and then the temperature is kept at 100℃ for 3h to obtain the acrylic epoxy resin.

[0084] Example 1

[0085] Under N2 atmosphere, 1 mol of cardanol (purity 88%) and 0.8 mol of N,N-diethyl-1,3-propanediamine were stirred and mixed at 80°C for 0.5 h, 0.9 mol (monomer molar amount) of paraformaldehyde was added in 4 portions at 73°C, the temperature was raised to 120°C for Mannich reaction for 2 h, 0.5 mol of ethylenediamine was added when the temperature was lowered to below 80°C, stirred and mixed for 0.5 h, 0.6 mol (monomer molar amount) of paraformaldehyde was added in 2 portions at 73°C, the temperature was raised to 120°C for reaction for 2 h, the vacuum degree was reduced to 5 kPa, and light components were removed at 120°C for 1 h to obtain cardanol aldehyde amine (denoted as cardanol aldehyde amine A);

[0086] Under N2 atmosphere, 60 parts by weight of the cardanol aldehyde amine and 24 parts by weight of the phosphite amino derivative were stirred and dissolved at 60°C for 2 h, a mixture liquid of 8 parts by weight of acrylic acid epoxy resin and 8 parts by weight of diethylene glycol diglycidyl ether was added at a constant speed at 70°C for 1 h, and the temperature was maintained for 6 h after the addition was completed to obtain a modified cardanol aldehyde amine curing agent.

[0087] Example 2

[0088] Under N2 atmosphere, 1 mol of cardanol (purity 88%) and 0.6 mol of N,N-diethyl-1,3-propanediamine were stirred and mixed at 50°C for 0.5 h, 0.8 mol (monomer molar amount) of paraformaldehyde was added in 4 portions at 74°C, Mannich reaction was carried out at 80°C for 6 h, 0.6 mol of ethylenediamine was added when the temperature was lowered to below 80°C, stirred and mixed for 0.5 h, 0.8 mol (monomer molar amount) of paraformaldehyde was added in 2 portions at 74°C, reaction was carried out at 80°C for 4 h, the vacuum degree was reduced to 2 kPa, and light components were removed at 80°C for 1 h to obtain cardanol aldehyde amine (denoted as cardanol aldehyde amine B);

[0089] Under N2 atmosphere, 60 parts by weight of the cardanol aldehyde amine and 24 parts by weight of the phosphite amino derivative were stirred and dissolved at 60°C for 2 h, a mixture liquid of 8 parts by weight of acrylic acid epoxy resin and 8 parts by weight of diethylene glycol diglycidyl ether was added at a constant speed at 70°C for 1 h, and the temperature was maintained for 6 h after the addition was completed to obtain a modified cardanol aldehyde amine curing agent.

[0090] Example 3

[0091] Under N2 atmosphere, 1 mol of cardanol (purity 88%) and 0.75 mol of N,N-dimethyl-1,3-propanediamine were stirred and mixed at 70°C for 0.5 h, 0.8 mol (monomer mol of formaldehyde) of paraformaldehyde was added in 4 portions at 73°C, Mannich reaction was carried out at 105°C for 5 h, 0.4 mol of diethylenetriamine was added when the temperature was lowered to below 80°C, stirred and mixed for 0.5 h, 0.6 mol (monomer mol of formaldehyde) of paraformaldehyde was added in 2 portions at 73°C, reacted at 120°C for 2 h, the vacuum degree was lowered to 4 kPa, and light components were removed at 120°C for 1 h to obtain cardanol aldehyde amine (denoted as cardanol aldehyde amine C).

[0092] Under N2 atmosphere, 70 parts by weight of the cardanol aldehyde amine and 20 parts by weight of the phosphite amino derivative were stirred and dissolved at 70°C for 2 h, a mixture of 5 parts by weight of an acrylic epoxy resin and 5 parts by weight of 1,4-butanediol diglycidyl ether was added at 80°C at a uniform speed for 0.5 h, and the temperature was maintained for 4 h after the addition was completed to obtain a modified cardanol aldehyde amine curing agent.

[0093] Example 4

[0094] Under N2 atmosphere, 1 mol of cardanol (purity 88%) and 0.75 mol of N,N-dimethyl-1,3-propanediamine were stirred and mixed at 70°C for 0.5 h, 0.8 mol (monomer mol of formaldehyde) of paraformaldehyde was added in 4 portions at 73°C, Mannich reaction was carried out at 105°C for 5 h, 0.4 mol of diethylenetriamine was added when the temperature was lowered to below 80°C, stirred and mixed for 0.5 h, 0.6 mol (monomer mol of formaldehyde) of paraformaldehyde was added in 2 portions at 73°C, reacted at 120°C for 2 h, the vacuum degree was lowered to 4 kPa, and light components were removed at 120°C for 1 h to obtain cardanol aldehyde amine (denoted as cardanol aldehyde amine C).

[0095] Under N2 atmosphere, 70 parts by weight of the cardanol aldehyde amine and 20 parts by weight of the phosphite amino derivative were stirred and dissolved at 70°C for 2 h, a mixture of 5 parts by weight of an acrylic epoxy resin and 5 parts by weight of 1,4-butanediol diglycidyl ether was added at 80°C at a uniform speed for 0.5 h, and the temperature was maintained for 4 h after the addition was completed to obtain a modified cardanol aldehyde amine curing agent.

[0096] Comparative Example 1

[0097] Commercially available cardanol aldehyde amine curing agent: commercially available from American East MD-650 cardanol curing agent, active hydrogen equivalent weight 180-200 g / eq.

[0098] Test Example

[0099] The modified cashew phenolic aldehyde amine curing agent of examples 1-4, the cashew phenolic aldehyde amine of examples 1-4 and the commercial cashew phenolic aldehyde amine curing agent of comparative example 1 were mixed with E51 type epoxy resin in a mass ratio of 1:1, respectively, and the viscosity of the obtained mixture was adjusted to a suitable spraying viscosity by a mixture of dimethylbenzene and n-butanol (mass ratio of dimethylbenzene and n-butanol was 3:1), then the mixture was sprayed on a polished tinplate and an unpolished cold-rolled steel sheet, respectively, and cured at room temperature for 7 days, and the coating performance was tested, the test standards and test results are shown in Tables 1-2:

[0100] Table 1 Test standards and test results of the modified cashew phenolic aldehyde amine curing agent of examples 1-4

[0101]

[0102] Table 2 Test standards and test results of the cashew phenolic aldehyde amine of examples 1-4 and the commercial cashew phenolic aldehyde amine curing agent of comparative example 1

[0103]

[0104] As shown in Tables 1-2, the scribed adhesion of the coating prepared by the modified cashew phenolic aldehyde amine curing agent of the present application on the tinplate substrate is 0-1 grade, and the scribed adhesion on the cold-rolled steel substrate reaches 1-2 grade, while the scribed adhesion of the coating prepared by the cashew phenolic aldehyde amine of examples 1-4 and the commercial cashew phenolic aldehyde amine curing agent of comparative example 1 on the tinplate substrate is 1-2 grade, and the adhesion on the cold-rolled steel substrate is 3-4 grade. Therefore, the modified cashew phenolic aldehyde amine curing agent of the present application has obvious improvement in adhesion, and is suitable for the field of coatings with high adhesion requirement, especially the field of cold-rolled steel substrate.

[0105] The above description is only the preferred embodiments of the present application, and does not limit the present application in any form. It should be noted that for ordinary skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should be considered as the protection scope of the present application.

Claims

1. An acrylic epoxy resin modified cardanol aldehyde amine epoxy curing agent, characterized in that, According to the weight percentage, the raw materials for the preparation include the following components: 60 to 80 parts of cardanol amine, 14 to 24 parts of phosphite amino derivatives, 3 to 8 parts of acrylic epoxy resin and 3 to 8 parts of diepoxy diluent; The preparation method of the cardanol aldehyde amine comprises the following steps: Under a protective atmosphere, cardanol, a first fatty amine, and a first paraformaldehyde are mixed to perform a first Mannich reaction to obtain a first product system; The first product system, the second fatty amine and the second paraformaldehyde are mixed and subjected to a second Mannich reaction to obtain the cardanol aldehyde amine; The first fatty amine includes one or more of N,N-diethyl-1,3-propylenediamine, N,N-dipropyl-1,3-propylenediamine and N,N-dibutyl-1,3-propylenediamine; The second fatty amine includes one or more of ethylenediamine, diethylenetriamine, triethylenetetramine and tetraethylenepentamine; The preparation method of the phosphite amino derivative comprises the following steps: In a protective atmosphere, paraformaldehyde is added to diethylenetriamine in batches, followed by an amine methylation reaction, and then diethyl phosphite is added to carry out a substitution reaction to obtain the phosphite amino derivative.

2. The acrylic acid epoxy resin modified cardanol aldehyde amine epoxy curing agent according to claim 1, wherein The molar ratio of the cardanol, the first fatty amine and the formaldehyde monomer in the first paraformaldehyde is 1: (0.6-0.8): (0.8-0.9); The molar ratio of the cardanol, the second fatty amine and the formaldehyde monomer in the second paraformaldehyde is 1: (0.4-0.6): (0.6-0.8).

3. The acrylic epoxy resin modified cardanol aldehyde amine epoxy curing agent according to claim 1 or 2, characterized in that, The temperature of the first Mannich reaction is 80-120° C. and the time is 2-6 hours; The temperature of the second Mannich reaction is 80-120° C., and the time is 2-4 hours.

4. The acrylic acid epoxy resin modified cardanol aldehyde amine epoxy curing agent according to claim 1, wherein The molar ratio of the diethylenetriamine, the formaldehyde monomer in the paraformaldehyde and the diethyl phosphite is 2: (1-1.3): 1; The temperature of the amine methylation reaction is 50-60°C and the holding time is 4-8 hours; The temperature of the substitution reaction is 60-80° C., and the insulation time is 10-14 hours.

5. The acrylic epoxy resin modified cardanol aldehyde amine epoxy curing agent according to claim 1, wherein The preparation method of the acrylic epoxy resin comprises the following steps: In a protective atmosphere, after mixing an epoxy resin, a first polymerization inhibitor and a catalyst, adding a mixed solution of acrylic acid and a second polymerization inhibitor at a temperature of 80-120° C. to carry out an addition reaction to obtain the acrylic epoxy resin; The temperature of the addition reaction is 100-120° C., and the insulation time is 2.5-3.5 hours.

6. The acrylic epoxy resin modified cardanol aldehyde amine epoxy curing agent according to claim 1, characterized in that, The diepoxy diluent includes one or more of 1,6-hexanediol diglycidyl ether, 1,4-butanediol diglycidyl ether, ethylene glycol diglycidyl ether, 1,4-cyclohexanedimethanol diglycidyl ether, diethylene glycol diglycidyl ether, dipropylene glycol diglycidyl ether and triethylene glycol diglycidyl ether.

7. The method for preparing the acrylic epoxy resin modified cardanol aldehyde amine epoxy curing agent according to any one of claims 1 to 6, characterized in that: The following steps are involved: In a protective atmosphere, after mixing the cardanol aldehyde amine and the phosphite amino derivative, a mixed solution of acrylic epoxy resin and diepoxy diluent is added to carry out modification to obtain the acrylic epoxy resin modified cardanol aldehyde amine epoxy curing agent.

8. Use of the acrylic epoxy resin modified phenol aldehyde amine epoxy curing agent according to any one of claims 1 to 6 or the acrylic epoxy resin modified phenol aldehyde amine epoxy curing agent prepared by the preparation method according to claim 7 in the field of coating.

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