A kind of cardanol phenol aldehyde amide curing agent, preparation method and application thereof

Abstract

The present invention discloses a cardanol phenolic amide curing agent, a preparation method thereof and an application thereof. The cardanol phenolic amide curing agent has the following structure: #imgabs0# wherein n is a natural number, R2 = H, alkyl, NH2 and polyamine, etc., and R3 = alkyl. The preparation method is to react brominated epoxy resin with cardanol to obtain cardanol-modified brominated epoxy resin, dehydrate and condense fatty acid with amine to obtain the corresponding amide. Finally, the cardanol-modified brominated epoxy resin reacts with formaldehyde and amide through Mannich reaction to obtain the cardanol phenolic amide curing agent. The cardanol phenolic amide curing agent of the present invention not only has the advantages of low toxicity, flexibility and can be rapidly cured at normal temperature and low temperature. Moreover, the cardanol phenolic amide curing agent contains a flame-retardant group (Br), which can improve the flame-retardant performance of the product while acting as a curing agent.

Description

Technical Field

[0001] The invention belongs to the field of polymer materials, and in particular relates to a cardanol phenolic aldehyde amide curing agent, a preparation method and application thereof. Background Art

[0002] As we all know, in the application of epoxy resin, curing agent is an important component. Among epoxy resin curing agents, low molecular weight fatty amines (such as ethylenediamine, diethylenetriamine, etc.) are gradually eliminated due to their high volatility and high toxicity. At present, the commonly used curing agents on the market are modified amine curing agents, mainly polyamide and Mannich base products. Among them, polyamide curing agents can be cured with epoxy resin to form a film at room temperature. Moreover, polyamide curing agents have a good toughening effect on the cured product, and the coating film also has good corrosion resistance. However, its low-temperature curing performance is poor. When the temperature is lower than 15°C, it cannot be constructed normally, and the drying time is long. In addition, it has high viscosity and low hardness; compared with polyamide curing agents, Mannich base has better low-temperature curing performance, and it can be constructed above 0°C. The biggest advantage is that the coating film has good sealing after curing, and has good oil and chemical resistance, but its biggest disadvantage is that the coating film is brittle and has poor toughness.

[0003] The fr-4 system is the dominant epoxy resin in the application of copper clad laminates. Its components include: epoxy resin, brominated epoxy resin flame retardant, curing agent, accelerator, solvent, etc. When using the continuous method to produce copper clad laminates, epoxy resin is required to cure quickly in a short time. The traditional fr-4 resin system uses dicyandiamide as a curing agent. Dicyandiamide has poor solubility and is insoluble in general solvents. It is only soluble in some strong polar solvents such as dimethylformamide. The boiling point of dimethylformamide is high (153°C). During the dipping process, the oven needs a higher temperature (about 180°C). These solvents have varying degrees of toxicity, which brings some inconvenience to production and management. At the same time, the brominated epoxy resin flame retardant is solid at room temperature, and it also needs to be dissolved and diluted with an organic solvent before use. Summary of the invention

[0004] The first technical problem to be solved by the present invention is to provide a solvent-free cardanol phenol aldehyde amide curing agent. The curing agent of the present invention contains a cardanol phenol aldehyde amide structure that can be cured quickly, which reduces the volatility and toxicity of low molecular weight fatty amines on the market; compared with polyamide curing agents, the curing speed is improved; compared with Mannich base, its toughness is improved; and the curing agent product contains a bromine (Br) flame retardant group, and has the dual properties of a curing agent and flame retardant. That is, the cardanol phenol aldehyde amide curing agent not only has the advantages of low toxicity, flexibility, and can be cured quickly at room temperature and low temperature. Not only that, the cardanol phenol aldehyde amide curing agent contains a flame retardant group (Br) that can improve the flame retardant performance of the product while acting as a curing agent.

[0005] The second technical problem to be solved by the present invention is to provide a method for preparing the above-mentioned cardanol phenol aldehyde amide curing agent. The preparation method comprises reacting brominated epoxy resin with cardanol to obtain brominated epoxy resin modified by cardanol, dehydrating and condensing fatty acid with amine to obtain corresponding amide, and finally, reacting the brominated epoxy resin modified by cardanol with formaldehyde and amide through Mannich reaction to obtain the cardanol phenol aldehyde amide curing agent.

[0006] The third technical problem to be solved by the present invention is to provide the application of the above-mentioned cardanol phenolic amide curing agent.

[0007] In order to solve the above-mentioned first technical problem, the present invention adopts the following technical solution:

[0008] A cardanol phenol aldehyde amide curing agent has the structure shown below:

[0009]

[0010] Where n is a natural number; R, R 1 All of them are carbon pentadecanyl; R 2 = alkyl or polyamine, R 3 =Alkyl.

[0011] As an embodiment, the R, R 1 It is a bond-line structure shown in any one of the following formulas (I), (II), (III), and (IV):

[0012]

[0013] In order to solve the above second technical problem, the present invention adopts the following technical solution:

[0014] The present invention provides a method for preparing a cardanol phenol aldehyde amide curing agent, comprising the following steps:

[0015] S1, reacting tetrabromobisphenol A and epichlorohydrin in the presence of a catalyst to obtain a brominated epoxy resin having epoxy groups capped at both ends;

[0016] S2, reacting cardanol with the brominated epoxy resin obtained in step S1 to obtain a brominated epoxy resin modified with cardanol;

[0017] S3, reacting the fatty acid with the amine to obtain the corresponding amide, and then further reacting the aldehyde and the amide with the brominated epoxy resin modified with the cardanol obtained in step S2 to obtain the cardanol phenol aldehyde amide curing agent.

[0018] As an embodiment, in step S1, the specific steps for preparing the brominated epoxy resin are as follows: tetrabromobisphenol A, a quaternary ammonium salt catalyst and an excess of epichlorohydrin are stirred and heated to 85-95°C, and reacted for 2-3h; excess epichlorohydrin is removed by reduced pressure distillation; the temperature is lowered to 55-65°C, a solvent toluene is added, and the mixture is stirred evenly; a sodium hydroxide solution with a mass concentration of 20-30% is added within 0.5-1.5h and stirred evenly, and the mixture is reacted for 4-6h; then the solvent toluene is added for extraction, and water is added for washing while hot to wash away the generated sodium chloride, and the mixture is separated; hot water at 55-65°C is added for washing once or more times, and the mixture is separated; finally, the solvent toluene is removed by reduced pressure distillation to obtain the brominated epoxy resin.

[0019] As an embodiment, in step S2, the specific steps for preparing the brominated epoxy resin modified by cardanol are as follows: the brominated epoxy resin, antioxidant and excess cardanol are heated to 95-105°C, triphenylphosphine catalyst is added and stirred to dissolve, and the temperature is continued to be raised to 170-190°C, and the reaction is carried out for 1-3 hours to obtain the brominated epoxy resin modified by cardanol.

[0020] As an embodiment, in step S3, the fatty acid is selected from one of isononanoic acid, lauric acid, and vegetable oleic acid.

[0021] As an embodiment, in step S3, the amine is selected from one or more of diethylenetriamine, ethylenediamine, triethylenetetramine, and tetraethylenepentamine.

[0022] As an embodiment, in step S3, the aldehyde is selected from formaldehyde, trioxymethylene and polyformaldehyde.

[0023] To solve the third technical problem mentioned above, the present invention adopts the following technical solution:

[0024] An application of the above-mentioned cardanol phenolic amide curing agent is to use the cardanol phenolic amide curing agent as a curing agent and a flame retardant epoxy polymer material.

[0025] An epoxy copper clad laminate composition comprises: an epoxy resin and the cardanol phenol aldehyde amide curing agent.

[0026] Any range described in the present invention includes the end value and any numerical value between the end values ​​and any sub-range formed by the end value or any numerical value between the end values.

[0027] Unless otherwise specified, all raw materials in the present invention can be purchased from the market, and the equipment used in the present invention can adopt conventional equipment in the relevant field or refer to the existing technology in the relevant field.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1) First, the present invention uses cardanol as a nucleophilic reagent, and the phenolic hydroxyl group in cardanol attacks the carbon atom of the epoxy group in the brominated epoxy resin, causing the CO bond to break, so that the epoxy group is ring-opened, and connected with the phenolic hydroxyl group to prepare a cardanol-modified brominated epoxy resin. Then, the fatty acid and the amino group at one end of the amine are subjected to an acylation reaction to generate the corresponding amide, and the aldehyde and the amino group at the other end of the amide undergo a Mannich reaction, the carbonyl group of the aldehyde is protonated, and the amine undergoes nucleophilic addition to the carbonyl group. After deprotonation, electron transfer of nitrogen, and water leaving steps, an iminium ion intermediate is obtained, which acts as an electrophilic reagent to attack the ortho-para active hydrogen of cardanol in the brominated epoxy resin modified by cardanol, and a cardanol phenolic aldehyde amide curing agent is obtained.

[0030] 2) During the synthesis process, mono-, di- and ternary products can be obtained by controlling the ratio of raw materials.

[0031] 3) The synthesized cardanol phenol aldehyde amide brominated epoxy curing agent successfully connects the cardanol structure, while giving it the flexibility and low toxicity brought by the unique long chain of cardanol and the low-temperature rapid curing property of cardanol phenol aldehyde amide. In addition, the curing agent product contains bromine (Br) flame retardant groups, and has the dual properties of curing agent and flame retardant. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0033] Figure 1 This is the infrared spectrum of the cardanol phenolic amide curing agent prepared in Example 3;

[0034] Figure 2 This is the infrared spectrum of the cardanol phenolic amide curing agent prepared in Example 4;

[0035] Figure 3 This is the infrared spectrum of the cardanol phenolic amide curing agent prepared in Example 5. DETAILED DESCRIPTION

[0036] In order to explain the present invention more clearly, the present invention is further described below in conjunction with preferred embodiments. It should be understood by those skilled in the art that the following specific description is illustrative rather than restrictive, and should not be used to limit the scope of protection of the present invention.

[0037] Unless otherwise specified, the methods used in the present invention are all conventional methods; the raw materials and devices used are all conventional commercially available products unless otherwise specified.

[0038] Cardanol was purchased from Zhejiang Wansheng Co., Ltd.;

[0039] Epoxy resin e51 was purchased from Shandong Jiufeng Chemical Co., Ltd.;

[0040] Curing agent c-19 was purchased from Shandong Jiufeng Chemical Co., Ltd.;

[0041] Defoamer B-459 was purchased from Guangdong Zhonglianban Fine Chemical Co., Ltd.;

[0042] The viscometer model is NDJ-8S, 4# rotor, purchased from Shanghai Lichen Bangxi Instrument Technology Co., Ltd.

[0043] Vegetable oleic acid was purchased from Nanjing Runbang Chemical Co., Ltd.;

[0044] Lauric acid was purchased from Tianjin Guangfu Technology Development Co., Ltd.;

[0045] Isononanoic acid was purchased from Shandong Yousuo Chemical Technology Co., Ltd.

[0046] As one aspect of the present invention, a cardanol phenol aldehyde amide curing agent of the present invention has the structure shown below:

[0047]

[0048] Where n is a natural number; R, R 1 All of them are carbon pentadecanyl; R 2 = alkyl or polyamine, R 3 =Alkyl.

[0049] According to some embodiments of the present invention, R, R 1 It is a bond-line structure shown in any one of the following formulas (I), (II), (III), and (IV):

[0050]

[0051] As another aspect of the present invention, a method for preparing the above-mentioned cardanol phenolic acid amide curing agent of the present invention comprises the following steps:

[0052] S1, reacting tetrabromobisphenol A and epichlorohydrin in the presence of a catalyst to obtain a brominated epoxy resin having epoxy groups capped at both ends;

[0053] S2, reacting cardanol with the brominated epoxy resin obtained in step S1 to obtain a brominated epoxy resin modified with cardanol;

[0054] S3, reacting the fatty acid with the amine to obtain the corresponding amide, and then further reacting the aldehyde and the amide with the brominated epoxy resin modified with the cardanol obtained in step S2 to obtain the cardanol phenol aldehyde amide curing agent.

[0055] According to certain embodiments of the present invention, in step S1, the specific steps for preparing the brominated epoxy resin are as follows: stirring tetrabromobisphenol A, a quaternary ammonium salt catalyst and an excess of epichlorohydrin and heating to 85-95°C, reacting for 2-3h; removing the excess epichlorohydrin by distillation under reduced pressure; cooling to 55-65°C, adding solvent toluene, and stirring evenly; adding a sodium hydroxide solution with a mass concentration of 20-30% within 0.5-1.5h and stirring evenly, reacting for 4-6h; then adding solvent toluene for extraction, adding water to wash while hot to wash away the generated sodium chloride, and separating the liquids; then adding 55-65°C hot water for washing once or more, and separating the liquids; finally removing the solvent toluene by distillation under reduced pressure to obtain the brominated epoxy resin.

[0056] According to certain embodiments of the present invention, in step S2, the specific steps for preparing the brominated epoxy resin modified by cardanol are as follows: heating the brominated epoxy resin, antioxidant and excess cardanol to 95-105°C, adding triphenylphosphine catalyst and stirring to dissolve, continuing to heat to 170-190°C, reacting for 1-3h, to obtain the brominated epoxy resin modified by cardanol.

[0057] According to some embodiments of the present invention, in step S3, the fatty acid is selected from one of isononanoic acid, lauric acid, and vegetable oleic acid.

[0058] According to some embodiments of the present invention, in step S3, the amine is selected from one or more of diethylenetriamine, ethylenediamine, triethylenetetramine, and tetraethylenepentamine.

[0059] According to some embodiments of the present invention, in step S3, the aldehyde is selected from formaldehyde, trioxymethylene and polyoxymethylene.

[0060] As another aspect of the present invention, the present invention provides an application of the above-mentioned cardanol phenolic amide curing agent, wherein the cardanol phenolic amide curing agent is used as a curing agent and a flame retardant epoxy polymer material.

[0061] According to some embodiments of the present invention, an epoxy copper clad laminate composition includes: an epoxy resin and the cardanol phenol aldehyde amide curing agent.

[0062] Example 1

[0063] The synthesis of brominated epoxy resin includes the following specific steps:

[0064] Weigh 410g of epichlorohydrin and 400g of tetrabromobisphenol A into a four-necked flask, install a reflux condenser and a thermometer, start heating, add benzyltriethylammonium chloride, stir and heat to 90°C, react for 2.5h, and remove excess epichlorohydrin by reduced pressure distillation; cool to 60°C, add 100g of solvent toluene, stir evenly, add 25% sodium hydroxide solution evenly within 1h and stir evenly, and react for 5h; then add 300g of solvent toluene for extraction, and add 400g of water to wash while hot to wash away the generated sodium chloride, and separate the liquids; then add 400g of hot water at 60°C for two consecutive times to wash, and separate the liquids; remove the solvent toluene by reduced pressure distillation to obtain a brominated epoxy resin.

[0065] Through experimental testing (hydrochloric acid-acetone method), it was found that the epoxy equivalent of the brominated epoxy resin was 350 g / equivalent.

[0066] Example 2

[0067] The synthesis of cardanol-modified brominated epoxy resin includes the following specific steps:

[0068] 350 g of the brominated epoxy resin prepared in Example 1, 335 g of cardanol and 0.8 g of antioxidant were weighed and added to a four-necked flask, heated to 100° C., stirred to dissolve, 2.8 g of triphenylphosphine catalyst was added to the reaction flask, and the temperature was continued to rise to 180° C. and reacted for 60 min. After the reaction was completed, a brominated epoxy resin modified with cardanol was obtained.

[0069] Through experimental testing (hydrochloric acid-acetone method), it was found that the epoxy equivalent of the brominated epoxy resin modified with cardanol was 6250 g / equivalent.

[0070] Example 3

[0071] A method for preparing a cardanol phenolic acid amide curing agent comprises the following steps:

[0072] Add 28.2g vegetable oleic acid and 20.6g diethylenetriamine to a flask, heat to 175℃ and react for 3h; after cooling, add 104.7g brominated epoxy resin modified by cardanol and 9.3g diethylenetriamine, stir, heat to 63℃, add 6.0g paraformaldehyde in batches, stir until paraformaldehyde is completely dissolved. Heat to 80℃ and react for 2h, heat to 110℃ and react for 1h; finally, remove water and free amine by vacuum distillation to obtain cardanol phenol aldehyde amide brominated epoxy curing agent.

[0073] The viscosity was 53135 cPs (25°C) after viscometer test. The amine value was found to be 155 mgKOH / g in experimental test. In order to further confirm the synthesis of the cardanol phenol aldehyde amide curing agent, the cardanol phenol aldehyde amide brominated epoxy curing agent prepared in Example 3 was characterized by infrared spectroscopy. The infrared spectrum is shown in the attached figure. Figure 1 shown.

[0074] pass Figure 1 It can be found that at 3290.8cm -1 The broad band at 3009.5cm is the stretching vibration peak of hydroxyl group and N—H bond; -1 The peak at 2921.5cm is the stretching vibration peak of the C=C bond of the long chain of cardanol; -1 and 2853.4cm -1 The peaks at 1649.9cm are all stretching vibration peaks of the C—H bond on the alkyl group; -1 The stretching vibration peak of the C=O bond of amide is at 1584.9 cm -1 and 1452.0cm -1 The peaks at 1267.6cm correspond to the in-plane bending vibration peaks of the NH bond and the CH bond; -1 and 1117.1cm -1 The peak at is the stretching vibration peak of the CN bond. This indicates that the cardanol phenol aldehyde amide curing agent has been successfully synthesized.

[0075] Example 4

[0076] A method for preparing a cardanol phenolic acid amide curing agent comprises the following steps:

[0077] Add 20.0g of lauric acid and 20.6g of diethylenetriamine to a flask, heat to 175℃ and react for 3h; after cooling, add 104.7g of brominated epoxy resin modified by cardanol and 9.3g of diethylenetriamine, stir, heat to 63℃, add 6.0g of paraformaldehyde in batches, stir until the paraformaldehyde is completely dissolved. Heat to 80℃ and react for 2h, then heat to 110℃ and react for 1h; finally, remove water and free amines by vacuum distillation to obtain cardanol phenol aldehyde amide brominated epoxy curing agent.

[0078] The viscosity was 110000 cPs (25°C) after viscometer test. The amine value was found to be 170 mgKOH / g in experimental test. In order to further confirm the synthesis of the cardanol phenol aldehyde amide curing agent, the cardanol phenol aldehyde amide brominated epoxy curing agent prepared in Example 3 was characterized by infrared spectroscopy. Figure 2 As shown. Figure 2 It can be found that at 3291.7cm -1The broad band at 3009.5cm is the stretching vibration peak of hydroxyl group and N—H bond; -1 The peak at 2921.5cm is the stretching vibration peak of the C=C bond of the long chain of cardanol; -1 and 2852.4cm -1 The peaks at 1649.9cm are all stretching vibration peaks of the C—H bond on the alkyl group; -1 The stretching vibration peak of the C=O bond of amide is at 1583.7cm -1 and 1452.1cm -1 The peaks at 1267.6cm correspond to the in-plane bending vibration peaks of the NH bond and the CH bond; -1 and 1117.1cm -1 The peak at is the stretching vibration peak of the CN bond. This indicates that the cardanol phenol aldehyde amide curing agent has been successfully synthesized.

[0079] Example 5

[0080] A method for preparing a cardanol phenolic acid amide curing agent comprises the following steps:

[0081] Add 15.8g isononanoic acid and 20.6g diethylenetriamine to a flask, heat to 175℃ and react for 3h; after cooling, add 104.7g brominated epoxy resin modified by cardanol and 9.3g diethylenetriamine, stir, heat to 63℃, add 6.0g paraformaldehyde in batches, stir until paraformaldehyde is completely dissolved. Heat to 80℃ and react for 2h, heat to 110℃ and react for 1h; finally, remove water and free amine by vacuum distillation to obtain cardanol phenol aldehyde amide brominated epoxy curing agent.

[0082] The viscosity was 130000 cPs (25°C) after viscometer test. The amine value was 178 mgKOH / g after experimental test. In order to further confirm the synthesis of the cardanol phenol aldehyde amide curing agent, the cardanol phenol aldehyde amide brominated epoxy curing agent prepared in Example 3 was characterized by infrared spectroscopy. Figure 3 As shown. Figure 3 It can be found that at 3290.8cm -1 The broad band at 3008.7.5cm is the stretching vibration peak of hydroxyl group and N—H bond; -1 The peak at 2921.5cm is the stretching vibration peak of the C=C bond of the long chain of cardanol; -1 and 2853.4cm -1 The peaks at 1648.9cm are all stretching vibration peaks of the C—H bond on the alkyl group; -1 The stretching vibration peak of the C=O bond of amide is at 1583.8cm -1 and 1452.1cm-1 The peaks at 1267.6cm correspond to the in-plane bending vibration peaks of the NH bond and the CH bond; -1 and 1117.1cm -1 The peak at is the stretching vibration peak of the CN bond. This indicates that the cardanol phenol aldehyde amide curing agent has been successfully synthesized.

[0083] Example 6

[0084] A method for preparing a cardanol phenolic acid amide curing agent comprises the following steps:

[0085] Repeat Example 3-5, replace diethylenetriamine with other amines (ethylenediamine, triethylenetetramine, tetraethylenepentamine, etc.), and keep other steps the same. The obtained cardanol phenolic amide curing agent exhibits similar effects to those of Example 3-5.

[0086] Calculation of curing agent dosage

[0087] Polyamine curing agents generally have a clear molecular structure and a total number of active hydrogen atoms in the molecular structure, so the utilization ratio of polyamine curing agents for curing epoxy resins can be directly calculated from this. Modified amines are suitable for this calculation method. The relative molecular weight of the product is calculated from the raw material ratio and relative molecular weight. Combined with the number of active hydrogen atoms consumed by the modified substance and the amount of the substance, the theoretical amount required for curing the resin can be roughly calculated. It represents the number of grams of curing agent required for curing every 100g of epoxy resin. The general formula for calculating the theoretical amount of curing agent is as follows:

[0088] X=M*E / N

[0089] Where: X is the mass of curing agent required to cure 100 parts of epoxy resin;

[0090] M——relative molecular weight of polyamine;

[0091] N——the number of active hydrogen atoms in the polyamine molecule;

[0092] E——Epoxy value of epoxy resin.

[0093] During use, the theoretical dosage and amine value are only a reference value. The two need to be combined and the actual performance of the cured product after curing should be examined to determine the best ratio.

[0094] According to the ratio of epoxy value to amine value of epoxy resin and curing agent, the prepared cardanol phenolic amide curing agents with different amine values ​​were added to epoxy resin E51 and applied as polymer flame retardants to flame retardant epoxy polymer materials, and their physical properties were tested by tensile and unnotched impact tests.

[0095] Application Example 1

[0096] An application of the above-mentioned cardanol phenolic acid amide curing agent comprises the following steps:

[0097] (1) Weigh 100 g of epoxy resin E51, place in a water bath at 80°C and heat for 30 min, and set aside;

[0098] (2) Place 168 g of the cardanol phenol formaldehyde amide brominated epoxy curing agent (Example 3) in a water bath at 80° C. and heat for 30 min for later use;

[0099] (3) Place the polytetrafluoroethylene mold in a drying oven and preheat to 80°C for use;

[0100] (4) Pour the curing agent heated in a water bath into the epoxy resin mixture, add 0.2 g of defoaming agent B-459, stir thoroughly, pour into a polytetrafluoroethylene mold, put the mold into an oven at 80°C for 2 hours, take it out, and place it at room temperature for curing for 4 hours. After the cured material in the mold is slowly cooled to room temperature, demold it and take it out to obtain a tensile test specimen and a notched impact test specimen.

[0101] Description: The polytetrafluoroethylene mold is provided with a cavity that matches the shape and size of the tensile test specimen and the unnotched impact test specimen.

[0102] Application Example 2

[0103] An application of the above-mentioned cardanol phenolic acid amide curing agent comprises the following steps:

[0104] Weigh 100g of epoxy resin E51, place it in a water bath at 80°C and heat it for 30min, and set it aside; and weigh 146g of cardanol phenolic amide brominated epoxy curing agent (Example 4) and place it in a water bath at 80°C and heat it for 30min, and set it aside; the other contents are exactly the same as those in Application Example 1, and will not be repeated here.

[0105] Application Example 3

[0106] An application of the above-mentioned cardanol phenolic acid amide curing agent comprises the following steps:

[0107] Weigh 100g of epoxy resin E51, place it in a water bath at 80°C and heat it for 30min, and set it aside; and weigh 137g of cardanol phenolic amide brominated epoxy curing agent (Example 5), place it in a water bath at 80°C and heat it for 30min, and set it aside; the other contents are exactly the same as those in Application Example 1, and will not be repeated here.

[0108] Application Example 4

[0109] An application of epoxy resin, the steps are as follows:

[0110] Weigh 100g of epoxy resin E51, place it in a water bath at 80°C and heat it for 30min, and set it aside; place 50g of curing agent C19 in a water bath at 80°C and heat it for 30min, and set it aside; the other contents are exactly the same as those in Application Example 1 and will not be repeated here.

[0111] Application Example 5

[0112] An application of the above-mentioned cardanol phenolic acid amide curing agent comprises the following steps:

[0113] Weigh 100g of epoxy resin E51, place it in a water bath at 80°C and heat it for 30min, and set aside; weigh 137g of cardanol phenol amide brominated epoxy curing agent (Example 5), add 9.13g of Sb 2 0 3 , placed in a water bath at 80°C and heated for 30 minutes, and set aside; the other contents are exactly the same as those in Application Example 1 and will not be repeated here.

[0114] The tensile test specimens and the unnotched impact test specimens prepared in the above-mentioned application examples 1-3 were respectively Conduct tensile tests and unnotched impact tests .in:

[0115] 1. Tensile test

[0116] Test standard for tensile test: "Determination of Tensile Properties of Plastics" (GB / T2567-2021).

[0117] Sample size: Prepare according to GB / T 2567-2021. The sample needs to be made into a dumbbell shape.

[0118] Test method: Clamp the sample so that the long axis of the sample is consistent with the tensile direction of the center line of the upper and lower clamps, continuously load at a certain speed until it is broken, and read the breaking load value. The loading speed is 2mm / min, and each group of samples is not less than 5. If the breaking point of the sample is not in the middle parallel part, the sample is invalid. The average value of all test data is the final test result. The test results are shown in the table below

[0119] Table 1: Tensile test results of application examples 1-3

[0120] Application Examples Tensile strength MPa Maximum elongation % Application Example 1 21.5 5 Application Example 2 32.1 7 Application Example 3 36.2 7.5

[0121] 2. Unnotched impact test

[0122] Test standard for unnotched impact test: GB / T1043.1-2008 "Determination of impact properties of plastic simply supported beams".

[0123] Sample specifications: length (80±2) mm, width (10±0.2) mm, thickness (4±0.2) mm, and span 60 mm.

[0124] Test method: Place the test piece symmetrically and vertically against the support, with the pendulum impact speed at 2.9m / s, release the pendulum steadily, and read the energy absorbed by the impact test. Each group of samples should be no less than 5. The average value of all test data is the final test result. See the table below for the test results

[0125] Table 2: Unnotched impact test results of application examples 1-3

[0126] Application Examples <![CDATA[Impact strength KJ / m 2 > Application Example 1 2.14 Application Example 2 3.45 Application Example 3 4.41

[0127] From Table 1 and Table 2 above, we can find that:

[0128] Among the cardanol phenol aldehyde amide curing agents synthesized by different fatty acids, the cardanol phenol aldehyde amide curing agent synthesized by isononanoic acid showed the best physical properties, with a tensile strength of 36.2MPa, a maximum elongation of 7.5%, and an impact strength of 4.41KJ / m 2 , which are 1.68 times, 1.5 times and 2.06 times of the vegetable oil acid synthetic cardanol phenolic amide curing agent respectively.

[0129] The flame retardant properties of the limiting oxygen index samples prepared in the above application examples 4-5 were tested respectively.

[0130] 3. Flame retardant performance test

[0131] Flame retardant test standard: "Determination of Combustion Behavior of Plastics by Oxygen Index Method" (GB / T2406.2-2009).

[0132] Sample size: According to GB / T2406.2-2009, 130×6.5×3mm 3 .

[0133] Test method: Use a sample clamp to clamp a sample of a certain size vertically in a transparent combustion tube, in which there is an upward flow of oxygen and nitrogen mixed in a certain proportion. Light the upper end of the sample, observe the subsequent combustion phenomenon, and record the continuous combustion time or the distance burned. When the burning time of the sample exceeds 3 minutes or the flame front exceeds the 50mm mark, reduce the oxygen concentration. When the burning time of the sample is less than 3 minutes or the flame front does not reach the mark, increase the oxygen concentration. Repeat this operation, gradually approaching the specified value from the upper and lower sides until the concentration difference between the two is less than 0.5%.

[0134] Table 3: Flame retardant test results of application examples 4-5

[0135] Application Examples Limiting oxygen index / % Application Example 4 17.4 Application Example 5 28.2

[0136] It can be found from Table 3 that compared with the non-flame retardant epoxy resin in Application Example 4, the sample strip prepared by the cardanol phenolic amide curing agent synthesized by the method of this patent (Application Example 5) has a limiting oxygen index of 28.2%, and the flame retardant performance is greatly improved through the synergistic flame retardancy of bromine and antimony.

[0137] The present invention uses cardanol as a nucleophilic reagent, and the phenolic hydroxyl group in cardanol attacks the carbon atom of the epoxy group in the brominated epoxy resin, causing the breakage of the CO bond, opening the epoxy group, and connecting with the phenolic hydroxyl group to prepare a brominated epoxy resin modified by cardanol. Then, the fatty acid and the amino group at one end of the amine are subjected to an acylation reaction to generate the corresponding amide, the aldehyde and the amino group at the other end of the amide undergo a Mannich reaction, the carbonyl group of the aldehyde is protonated, and the amine undergoes nucleophilic addition to the carbonyl group, and after deprotonation, electron transfer of nitrogen, and water leaving steps, an imide ion intermediate is obtained, which, as an electrophilic reagent, attacks the ortho-para active hydrogen of cardanol in the brominated epoxy resin modified by cardanol, and a cardanol phenol aldehyde amide curing agent is obtained. The synthesized cardanol phenol aldehyde amide curing agent successfully connects the cardanol structure, and at the same time gives it the flexibility, low toxicity and low-temperature rapid curing brought by the unique long chain of cardanol. A cardanol phenol aldehyde amide curing agent provided by the present application not only reduces the toxicity of the polyamine curing agent, but also improves its flexibility. Most importantly, the cardanol phenol aldehyde amide brominated epoxy curing agent product provided by the present application contains a flame retardant group (Br) which can improve the flame retardant performance of the product while acting as a curing agent. Finally, the present invention provides an epoxy copper clad laminate composition, comprising: an epoxy resin and the cardanol phenol aldehyde amide brominated epoxy curing agent; the composition has excellent curing performance and flame retardant performance.

[0138] Obviously, the above embodiments of the present invention are merely examples for clearly explaining the present invention, and are not intended to limit the implementation methods of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is impossible to list all implementation methods here. Any obvious changes or modifications derived from the technical solution of the present invention are still within the scope of protection of the present invention.

Claims

1. A cardanol phenol aldehyde amide curing agent, It is characterized in that Has the following structure: Where n is a natural number; R, R 1 All of them are carbon pentadecanyl; R 2 = alkyl or polyamine, R 3 =Alkyl.

2. The cardanol phenol aldehyde amide curing agent according to claim 1, Features: The R, R 1 It is a bond-line structure shown in any one of the following formulas (I), (II), (III), and (IV):

3. The method for preparing the cardanol phenol aldehyde amide curing agent according to claim 1 or 2, It is characterized in that The steps include: S1, reacting tetrabromobisphenol A and epichlorohydrin in the presence of a catalyst to obtain a brominated epoxy resin having epoxy groups capped at both ends; S2, reacting cardanol with the brominated epoxy resin obtained in step S1 to obtain a brominated epoxy resin modified with cardanol; S3, reacting the fatty acid with the amine to obtain the corresponding amide, and then further reacting the aldehyde and the amide with the brominated epoxy resin modified with the cardanol obtained in step S2 to obtain the cardanol phenol aldehyde amide curing agent.

4. The preparation method according to claim 3, Features: In step S1, the specific steps of preparing the brominated epoxy resin are as follows: stirring tetrabromobisphenol A, a quaternary ammonium salt catalyst and excess epichlorohydrin and heating to 85-95° C., reacting for 2-3 hours; removing excess epichlorohydrin by reduced pressure distillation; cooling to 55-65° C., adding solvent toluene, and stirring evenly; adding a sodium hydroxide solution with a mass concentration of 20-30% within 0.5-1.5 hours and stirring evenly, reacting for 4-6 hours; then adding solvent toluene for extraction, adding water for washing while hot to wash away generated sodium chloride, and separating the liquids; then adding 55-65° C. hot water for washing once or multiple times, and separating the liquids; finally removing the solvent toluene by reduced pressure distillation to obtain the brominated epoxy resin.

5. The preparation method according to claim 3, Features: In step S2, the specific steps for preparing the brominated epoxy resin modified by cardanol are as follows: the brominated epoxy resin, antioxidant and excess cardanol are heated to 95-105°C, triphenylphosphine catalyst is added and stirred to dissolve, the temperature is continued to be raised to 170-190°C, and the reaction is carried out for 1-3 hours to obtain the brominated epoxy resin modified by cardanol.

6. The preparation method according to claim 3, Features: In step S3, the fatty acid is selected from one of isononanoic acid, lauric acid and vegetable oleic acid.

7. The preparation method according to claim 3, Features: In step S3, the amine is selected from one or more of diethylenetriamine, ethylenediamine, triethylenetetramine, and tetraethylenepentamine.

8. The preparation method according to claim 3, Features: In step S3, the aldehyde is selected from formaldehyde, trioxymethylene or polyformaldehyde.

9. The use of a cardanol phenol aldehyde amide curing agent as claimed in any one of claims 1 to 2, Features: The cardanol phenolic amide curing agent structure is used as a curing agent in flame retardant epoxy polymer materials.

10. An epoxy copper clad laminate composition, Features: The invention comprises an epoxy resin and the cardanol phenol aldehyde amide curing agent according to any one of claims 1 to 2.

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