A method for preparing a modified phenolic amide curing agent and epoxy cured product

Abstract

The invention discloses a preparation method of a modified phenolic amide curing agent and an epoxy cured product, which belongs to the field of synthetic resins and comprises the following steps: S1, taking soybean oleic acid and methylcyclohexanediamine, stirring evenly, heating to 150-250°C, keeping the temperature for reaction for 2-8h, cooling after the reaction is finished; S2, adding cardanol and polyformaldehyde, heating to 80-120°C, keeping the temperature for reaction for 2-8h, and obtaining a modified phenolic amide curing agent after dehydration; wherein, soybean oleic acid: methylcyclohexanediamine: cardanol: polyformaldehyde weight parts = 200-350: 50-300: 100-200: 5-30; the weight parts are one of grams, kilograms, kilograms, thousands of kilograms or ten thousand kilograms; in S1, 90-200 weight parts of high temperature orange flower extract are also added. The curing agent prepared by the invention has good performance and low cost.

Description

Technical Field

[0001] The invention relates to the field of synthetic resins, and in particular to a method for preparing a modified phenolic acid amide curing agent and an oxygen cured product. Background Art

[0002] Epoxy resin is easy to cure, has a simple process, and does not require excessive pressure. It and epoxy curing agent constitute a common epoxy coating system.

[0003] US20110020555A1 discloses a two-component epoxy resin composition, which can cure faster at low ambient temperature to quickly form a non-sticky coating and seal with good appearance. The curing agent is a cardanol modified phenalkamine curing agent.

[0004] Although the cardanol modified phenolic amine curing agent has low viscosity and excellent low temperature curing performance, and can be applied at -10°C without affecting the construction process, the existing cardanol modified phenolic amine curing agent has the following shortcomings:

[0005] (1) When used with epoxy resin, the added amount is large.

[0006] (2) The high reaction heat during curing may lead to quality problems, such as decomposition of the cured product.

[0007] (3) The cost is relatively high.

[0008] The above background technology is for facilitating the understanding of the present invention and is not a known technology disclosed to the general public before the application of the present invention. Summary of the invention

[0009] In view of the above-mentioned defects, the present invention provides a method for preparing a modified phenolic amide curing agent, which aims to improve at least one of the problems mentioned in the background technology.

[0010] The technical solution is: a method for preparing a modified phenolic amide curing agent, comprising the following steps:

[0011] S1, take soybean oleic acid and methylcyclohexanediamine, stir evenly, heat to 150-250℃, keep warm for 2-8h, and cool down after the reaction is finished;

[0012] S2, add cardanol and polyformaldehyde, raise the temperature to 80-120°C, keep the temperature for reaction for 2-8 hours, and obtain a modified phenolic amide curing agent after dehydration;

[0013] Wherein, soybean oleic acid: methylcyclohexanediamine: cardanol: polyformaldehyde weight parts = 200~350: 50~300: 100~200: 5~30; weight parts are one of grams, kilograms, kilograms, thousand kilograms or ten thousand kilograms;

[0014] In S1, 90 to 200 parts by weight of high temperature orange flower extract is also added.

[0015] Furthermore, the weight ratio of soybean oleic acid: methylcyclohexanediamine: cardanol: paraformaldehyde is 250-300: 60-260: 130-160: 15-20.

[0016] Furthermore, the degree of polymerization of the paraformaldehyde is 20.

[0017] Furthermore, the high temperature orange flower extract is prepared by the following steps:

[0018] S01, pick 2kg of fresh orange flowers;

[0019] S02, transporting the orange flowers from the feed port into the vacuum extraction tank for vacuum extraction, with a vacuum degree of 0.1-0.2MPa and an extraction temperature of 35-55°C;

[0020] S03, condensing and collecting the low-temperature gas coming out of the gas outlet, using low-temperature water of 6-10°C for cooling the condenser, and collecting the low-temperature orange flower extract, which is used for the preparation of medicine or fragrance;

[0021] S04, reduce the vacuum degree of the extraction equipment and continue extraction, the vacuum degree is 0.06-0.09MPa, and the extraction temperature is 60-80°C;

[0022] S05, condensing and collecting the medium-temperature gas coming out of the gas outlet, using low-temperature water of 25-30°C for cooling the condenser, and collecting the medium-temperature orange flower extract, which is used for the preparation of medicine or fragrance;

[0023] S06, reduce the vacuum degree of the extraction equipment and continue extraction, the vacuum degree is 0.03-0.05MPa, and the extraction temperature is 90-130°C;

[0024] S07, the high-temperature gas volatilized from the gas outlet is condensed and collected, the cooling water of the condenser is low-temperature water of 25~30℃, and the collected liquid is the high-temperature orange flower extract.

[0025] Furthermore, the weight proportion of soybean oleic acid: methylcyclohexanediamine: high temperature orange flower extract: cardanol: polyformaldehyde is 260:128:200:100:20.

[0026] Furthermore, the weight proportion of soybean oleic acid: methylcyclohexanediamine: high temperature orange flower extract: cardanol: polyformaldehyde is 275:195:93:125:20.

[0027] The invention also provides a method for preparing the epoxy cured product.

[0028] The technical solution is: a method for preparing an epoxy cured product, wherein the epoxy resin and a curing agent are combined to form the epoxy cured product, and the curing agent is a modified phenolic amide curing agent prepared by the above method.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The inventor team of the present invention has selected a formula composition and an optimal ratio through a large number of experiments, which has good salt spray corrosion resistance, a small addition amount when used with epoxy resin, a low peak temperature of the curing reaction, and a short curing time. In order to reduce costs, a large number of experiments have been conducted to select a high-temperature orange flower extract that is used as waste in the prior art and is compatible with the formula as a formula composition. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The extraction device used in Examples 1 to 3 of the present invention;

[0032] In the figure: 1. vacuum extraction tank, 2. feed port, 3. gas outlet, 4. coil, 5. collection tank, 6. condenser. DETAILED DESCRIPTION

[0033] The present invention will be further described below in conjunction with embodiments.

[0034] In the present invention, unless otherwise specified, the products involved in the following embodiments and comparative examples are all purchased from the market.

[0035] In the present invention, when carrying out the embodiments, comparative examples and performance tests, relevant safety operation specifications for chemicals and experiments are followed.

[0036] Example 1

[0037] S01, pick 2kg of fresh orange flowers and chop them into 0.5-1cm pieces.

[0038] S02, convey the crushed orange flowers from the feed port into the vacuum extraction tank for vacuum extraction, with a vacuum degree of 0.1MPa and an extraction temperature of about 45°C.

[0039] S03, condense and collect the low-temperature gas coming out of the gas outlet, the cooling water of the condenser adopts low-temperature water of 6~10℃, and the collected liquid is the low-temperature orange flower extract.

[0040] S04, reduce the vacuum degree of the extraction equipment and continue extraction, the vacuum degree is 0.08MPa, and the extraction temperature is about 70℃.

[0041] S05, the medium-temperature gas coming out of the outlet is condensed and collected, the cooling water of the condenser is low-temperature water of 25~30℃, and the collected liquid is the medium-temperature orange flower extract.

[0042] S06, reduce the vacuum degree of the extraction equipment and continue extraction, the vacuum degree is 0.04MPa, and the extraction temperature is about 120℃.

[0043] S07, the high-temperature gas volatilized from the gas outlet is condensed and collected, the cooling water of the condenser is low-temperature water of 25~30℃, and the collected liquid is the high-temperature orange flower extract.

[0044] The low temperature orange flower extract and the medium temperature orange flower extract of this embodiment are used in the field of medicine or perfume. The high temperature orange flower extract of this embodiment is used in subsequent experiments (the extract of vacuum extraction in the high temperature section, due to the high extraction temperature, weakly adding this part of the liquid to the low temperature section and the medium temperature section will affect the quality of the entire extract, and the entire fragrance will be weakened. If it is discarded as waste, it will be a waste and increase the production cost).

[0045] Example 2

[0046] S01, pick 1kg of fresh jasmine flowers and chop them into 0.5-1cm pieces.

[0047] S02, conveying the crushed jasmine flowers from the feed port into a vacuum extraction tank for vacuum extraction, with a vacuum degree of 0.1 MPa and an extraction temperature of about 45°C.

[0048] S03, condense and collect the low-temperature gas coming out of the gas outlet, the cooling water of the condenser adopts low-temperature water of 6~10℃, and the collected liquid is the low-temperature jasmine extract.

[0049] S04, reduce the vacuum degree of the extraction equipment and continue extraction, the vacuum degree is 0.08MPa, and the extraction temperature is about 70℃.

[0050] S05, condense and collect the medium-temperature gas coming out of the gas outlet, the cooling water of the condenser adopts low-temperature water of 25~30℃, and the collected liquid is the medium-temperature jasmine extract.

[0051] S06, reduce the vacuum degree of the extraction equipment and continue extraction, the vacuum degree is 0.04MPa, and the extraction temperature is about 120℃.

[0052] S07, condensing and collecting the high-temperature gas volatilized from the gas outlet, the cooling water of the condenser adopts low-temperature water of 25-30°C, and the collected liquid is the high-temperature jasmine extract.

[0053] The low-temperature jasmine extract and the medium-temperature jasmine extract of this embodiment are used in the field of medicine or perfume. The high-temperature jasmine extract of this embodiment is used in subsequent experiments (the extract of the high-temperature vacuum extraction, due to the high extraction temperature, weakly adding this part of the liquid to the low-temperature and medium-temperature sections will affect the quality of the entire extract, and the entire fragrance will be weakened. If it is discarded as waste, it will be a waste and increase the production cost).

[0054] Example 3

[0055] S01, pick 1kg of fresh rose flowers and chop them into 0.5-1cm pieces.

[0056] S02, convey the crushed roses into the vacuum extraction tank from the feed port for vacuum extraction, with a vacuum degree of 0.1 MPa and an extraction temperature of about 45°C.

[0057] S03, the low-temperature gas coming out of the gas outlet is condensed and collected, the cooling water of the condenser uses low-temperature water of 6~10℃, and the collected liquid is the low-temperature rose extract.

[0058] S04, reduce the vacuum degree of the extraction equipment and continue extraction, the vacuum degree is 0.08MPa, and the extraction temperature is about 70℃.

[0059] S05, the medium-temperature gas coming out of the gas outlet is condensed and collected, the cooling water of the condenser is low-temperature water of 25~30℃, and the collected liquid is the medium-temperature rose extract.

[0060] S06, reduce the vacuum degree of the extraction equipment and continue extraction, the vacuum degree is 0.04MPa, and the extraction temperature is about 120℃.

[0061] S07, the high-temperature gas volatilized from the gas outlet is condensed and collected, the cooling water of the condenser is low-temperature water of 25~30℃, and the collected liquid is the high-temperature rose extract.

[0062] The rose extract in the low temperature section and the rose extract in the medium temperature section of this embodiment are used in the field of medicine or perfume. The rose extract in the high temperature section of this embodiment is used in subsequent experiments (in the extract extracted by vacuum extraction in the high temperature section, due to the high extraction temperature, if this part of the liquid is weakly added to the low temperature section and the medium temperature section, the quality of the entire extract will be affected, and the entire fragrance will be weakened. If it is discarded as waste, it will be a waste and increase the production cost).

[0063] The extraction devices in the above-mentioned Examples 1 to 3 are purchased from the market. Figure 1, including a vacuum extraction tank 1 and a collecting tank 5, the vacuum extraction tank 1 is provided with a feed port 2 and an air outlet 3, a coil 4 is provided in the interlayer of the vacuum extraction tank 1, the upper end and the lower end of the coil 4 respectively extend out of the interlayer, the upper end of the coil 4 is connected to water vapor, a condenser 6 is connected between the air outlet 3 and the collecting tank 5, and the collecting tank 5 is also connected to a vacuum pump for evacuating the vacuum extraction tank 1.

[0064] Example 4

[0065] S1, take 282g soybean oleic acid and 256g methylcyclohexanediamine (HTDA), stir evenly, heat to 200℃, keep warm for 3h, and after the reaction, cool to 50℃.

[0066] S2, add 150 g of cardanol and 20 g of paraformaldehyde (degree of polymerization n=20), heat to 120°C, keep warm for 3 hours, then heat to 150°C for dehydration for 30 minutes.

[0067] Example 5

[0068] S1, take 282g soybean oleic acid and 128g methylcyclohexanediamine (HTDA), stir evenly, heat to 200℃, keep warm for 3h, and after the reaction, cool to 50℃.

[0069] S2, add 150 g of cardanol and 20 g of paraformaldehyde (degree of polymerization n=20), raise the temperature to 120°C, keep the temperature for reaction for 3 hours, and then raise the temperature to 150°C for dehydration for 30 minutes.

[0070] Example 6

[0071] S1, take 282g soybean oleic acid and 64g methylcyclohexanediamine (HTDA), stir evenly, heat to 200℃, keep warm for 3h, and after the reaction, cool to 50℃.

[0072] S2, add 150 g of cardanol and 20 g of paraformaldehyde (degree of polymerization n=20), heat to 120°C, keep warm for 3 hours, then heat to 150°C for dehydration for 30 minutes.

[0073] Example 7

[0074] S1, take 260 g soybean oleic acid, 128 g methylcyclohexanediamine (HTDA), and 200 g high-temperature orange flower extract obtained in Example 1, stir evenly, heat to 200° C., and keep warm for 3 h. After the reaction is completed, cool to 50° C.

[0075] S2, add 100 g of cardanol and 20 g of polyformaldehyde, raise the temperature to 120°C, keep the temperature for reaction for 3 hours, and then raise the temperature to 150°C for dehydration for 30 minutes.

[0076] Example 8

[0077] S1, take 275 g soybean oleic acid, 195 g methylcyclohexanediamine (HTDA), and 93 g high-temperature orange flower extract obtained in Example 1, stir evenly, heat to 200° C., and keep warm for 3 h. After the reaction is completed, cool to 50° C.

[0078] S2, add 125 g of cardanol and 20 g of polyformaldehyde, raise the temperature to 120°C, keep the temperature for reaction for 3 hours, and then raise the temperature to 150°C for dehydration for 30 minutes.

[0079] Comparative Example 1

[0080] S1, take 282g soybean oleic acid and 256g methylcyclopentanediamine, stir evenly, heat to 200℃, keep warm for 3h, and after the reaction, cool to 50℃.

[0081] S2, add 150 g of cardanol and 20 g of paraformaldehyde, raise the temperature to 120°C, keep the temperature for reaction for 3 hours, and then raise the temperature to 150°C for dehydration for 30 minutes.

[0082] Comparative Example 2

[0083] S1, take 282g soybean oleic acid and 256g isophorone diamine (IPDA), stir evenly, heat to 200℃, keep warm for 3h, and after the reaction, cool to 50℃.

[0084] S2, add 150 g of cardanol and 20 g of paraformaldehyde, raise the temperature to 120°C, keep the temperature for reaction for 3 hours, and then raise the temperature to 150°C for dehydration for 30 minutes.

[0085] Comparative Example 3

[0086] S1, take 275 g soybean oleic acid, 195 g methylcyclohexanediamine (HTDA), and 93 g high-temperature jasmine extract extracted in Example 2, stir evenly, heat to 200° C., keep warm for 3 h, and after the reaction is completed, cool to 50° C.

[0087] S2, add 125 g of cardanol and 20 g of polyformaldehyde, raise the temperature to 120°C, keep the temperature for reaction for 3 hours, and then raise the temperature to 150°C for dehydration for 30 minutes.

[0088] Comparative Example 4

[0089] S1, take 275 g soybean oleic acid, 195 g methylcyclohexanediamine (HTDA), and 93 g high-temperature rose extract obtained in Example 3, stir evenly, heat to 200° C., and keep warm for 3 h. After the reaction is completed, cool to 50° C.

[0090] S2, add 125 g of cardanol and 20 g of polyformaldehyde, raise the temperature to 120°C, keep the temperature for reaction for 3 hours, and then raise the temperature to 150°C for dehydration for 30 minutes.

[0091] Comparative Example 5

[0092] The curing agent in this comparative example is methylcyclohexanediamine (HTDA).

[0093] Example 9

[0094] The curing agents obtained from Examples 4 to 8 and Comparative Examples 1 to 4 were subjected to a salt spray corrosion resistance test according to GB / T1771. The results are shown in Table 1:

[0095] Table 1 Salt spray corrosion resistance test results

[0096]

[0097] From the results in Table 1, it can be seen that compared with Example 4-Example 6, the amount of methylcyclohexanediamine added in the formula is higher, and better salt spray resistance can be obtained. Compared with Example 7-Example 8, the salt spray resistance of Example 8 is better than that of Example 7. Compared with Example 1-Example 3, Example 7-Example 8, and Comparative Example 3-Comparative Example 4, although the salt spray resistance of Example 7 after the addition of the high-temperature orange flower extract is worse than that of Example 4-Example 6, it still achieves the effect of no bubbles at the scratch of 1550h, and the effect of Example 8 is even better than that of Example 6; while the high-temperature jasmine extract of Comparative Example 3 and the high-temperature rose extract of Comparative Example 4 are included in the formula, although the cost is reduced, the salt spray resistance drops sharply, and bubbles appear at the scratch of 900h. Comparing Example 4 with Comparative Examples 1-Comparative Examples 2, although they are both diamines, and even the structures of methylcyclohexanediamine and methylcyclopentanediamine are relatively similar, the effects in the formula are quite different, and it is obvious that methylcyclohexanediamine is more in line with the formula. Comparing Examples 4 to 6 with Comparative Example 5, the synthesis of methylcyclohexanediamine participating in the curing agent is significantly better than that of methylcyclohexanediamine alone as a curing agent.

[0098] Example 10

[0099] The curing agents of Example 4, Comparative Example 1, Comparative Example 2 and Comparative Example 5 were mixed with epoxy resin to form films. Under the same amount of the same epoxy resin (based on 100), the dosage of the curing agent was as shown in Table 2 below:

[0100] Table 2 Results of different curing agent dosages

[0101]

[0102] It can be seen from the results in Table 2 that, under the same epoxy resin dosage, the curing agent dosage in Example 4 is the least.

[0103] Embodiment 11

[0104] The curing agent and epoxy resin of Example 4, Comparative Example 1, Comparative Example 2 and Comparative Example 5 were mixed in the same ratio as that of Example 10, and the curing agent and epoxy resin were placed in a container in a water bath, and the curing time was measured. The heat release peak temperature was calculated according to the temperature change of the water in the water bath. The results are shown in Table 3:

[0105] Table 3 Curing time and peak heat release temperature of different curing agents

[0106]

[0107] It can be seen from Table 3 that, at the same amount of epoxy resin, Example 4 has a much lower heat release peak temperature than Comparative Examples 1, 2 and 5, and has a shorter curing time, better compatibility with epoxy resin, and better formed film layer.

[0108] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a modified phenolic amide curing agent, characterized in that: The following steps are involved: S1, take soybean oleic acid and methylcyclohexanediamine, stir evenly, heat to 150-250℃, keep warm for 2-8h, and cool down after the reaction is finished; S2, add cardanol and polyformaldehyde, raise the temperature to 80-120°C, keep the temperature for reaction for 2-8h, and obtain the modified phenolic amide curing agent after dehydration; Wherein, soybean oleic acid: methylcyclohexanediamine: cardanol: polyformaldehyde weight parts = 200~350: 50~300: 100~200: 5~30; weight parts are one of grams, kilograms, thousands of kilograms or ten thousand kilograms; In S1, 90 to 200 parts by weight of high temperature orange flower extract is also added.

2. The method for preparing the modified phenolic amide curing agent according to claim 1, characterized in that: The weight proportion of soybean oleic acid: methylcyclohexanediamine: cardanol: polyformaldehyde is 250-300: 60-260: 130-160: 15-20.

3. The preparation method of the modified phenolic amide curing agent according to claim 1, characterized in that, The degree of polymerization of the paraformaldehyde=20.

4. The method for preparing the modified phenolic amide curing agent according to claim 1, characterized in that: The high temperature section orange flower extract is prepared by the following steps: S01, pick 2kg of fresh orange flowers; S02, transporting the orange flowers from the feed port into the vacuum extraction tank for vacuum extraction, with a vacuum degree of 0.1-0.2MPa and an extraction temperature of 35-55°C; S03, condensing and collecting the low-temperature gas coming out of the gas outlet, using low-temperature water of 6-10°C for cooling the condenser, and collecting the low-temperature orange flower extract, which is used for the preparation of medicine or fragrance; S04, reduce the vacuum degree of the extraction equipment and continue extraction, the vacuum degree is 0.06-0.09MPa, and the extraction temperature is 60-80℃; S05, condensing and collecting the medium-temperature gas coming out of the gas outlet, using low-temperature water of 25-30°C for cooling the condenser, and collecting the medium-temperature orange flower extract, which is used for the preparation of medicine or fragrance; S06, reduce the vacuum degree of the extraction equipment and continue extraction, the vacuum degree is 0.03-0.05MPa, and the extraction temperature is 90-130°C; S07, the high-temperature gas volatilized from the gas outlet is condensed and collected, the cooling water of the condenser is low-temperature water of 25~30℃, and the collected liquid is the high-temperature orange flower extract.

5. The method for preparing the modified phenolic amide curing agent according to claim 1, characterized in that: The weight proportion of soybean oleic acid: methylcyclohexanediamine: high temperature orange flower extract: cardanol: polyformaldehyde is 260:128:200:100:

20.

6. The method for preparing the modified phenolic amide curing agent according to claim 1, characterized in that: The weight proportions of soybean oleic acid: methylcyclohexanediamine: high temperature orange flower extract: cardanol: polyformaldehyde are 275:195:93:125:

20.

7. A method for preparing an epoxy cured product, wherein an epoxy resin and a curing agent are combined to form an epoxy cured product, characterized in that: The curing agent is a modified phenolic amide curing agent prepared by the method described in any one of claims 1 to 6.

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