Synthesis method of polyaspartic ester, application thereof and polyurea coating

Abstract

The application relates to the field of IPC C07C227, and more particularly to a polyaspartic ester synthesis method and application thereof and a polyurea coating. The method comprises the following steps: S1, under the condition of 40-60 DEG C and nitrogen atmosphere, dialkyl maleate is added dropwise into alicyclic diamine, and after the dropwise addition is completed, heat preservation is carried out for 1-3 hours; S2, heat preservation reaction is carried out at 80-90 DEG C for 24-48 hours, solid content and residual primary amine content are determined, and an initial product is obtained; and S3, the initial product is continuously heated to 90-140 DEG C, lactone is added dropwise, and heat preservation is carried out for 6-12 hours, and the polyurea coating is obtained. The residual primary amine can be reduced from more than 20 mg KOH / g to 1 mg KOH / g within 6-18 hours, and the whole preparation time can be controlled to be between 40 hours and 60 hours. The prepared polyurea has the advantages of prolonging gel time, improving flexibility, and improving temperature and humidity sensitivity.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of polyaspartic ester technology, especially to the field of IPC C07 C227, and more particularly to a synthesis method of polyaspartic ester and application thereof and a polyurea coating. BACKGROUND

[0002] Polyaspartic ester is prepared by Michael addition reaction of aliphatic polyamine and dialkyl maleate. Michael addition converts the primary amine of aliphatic polyamine into secondary amine, so it has more adjustable gel time compared with traditional polyurea. However, Michael addition is difficult to react completely, and as the reaction time goes on, the time required for the conversion rate of primary amine to increase is greatly prolonged as the residual amount decreases. Moreover, the longer the activation period of the prepared polyaspartic ester resin, the slower the reaction of the amine and dialkyl maleate, and the longer the preparation time required.

[0003] CN1952029A discloses an amino-terminated polyaspartic ester and a preparation method thereof, which is prepared by a two-step method: (1) a small molecule amine is reacted with an excess of a dicarboxylic acid ester to form a mixture containing a first polyaspartic ester and unreacted dicarboxylic acid ester remaining due to the excess; (2) the mixture obtained in step (1) is added dropwise into a polyalkylene ether polyamine to obtain the final product by catalytic reaction. It takes six months to achieve a yield of 95% and 12 weeks to 8 months to achieve complete reaction for the synthesis of polyaspartic ester. CN114206964A discloses a rapid preparation of polyaspartic ester containing low primary amine and the use of these polyaspartic esters in slow-reacting polyurea systems. 4,4'-diamino-dicyclohexyl methane (HMDA) and 3,3'-dimethyl-4,4'-diamino-dicyclohexyl methane (DMDC) and maleic acid diethyl ester are used as examples to prepare a slow-reacting polyurea system. There is still residual diamine in the fourth week, and the monoaspartic ester still accounts for a high proportion in the eighth week. 12 MDA) and 3,3'-dimethyl-4,4'-diamino-dicyclohexyl methane (DMDC) and maleic acid diethyl ester are used as examples to prepare a slow-reacting polyurea system. There is still residual diamine in the fourth week, and the monoaspartic ester still accounts for a high proportion in the eighth week.

[0004] Although increasing the amount of dialkyl maleate can accelerate the conversion rate of primary amine, the prepared polyaspartic ester has low solid content. In addition, epoxy resin can be added later to accelerate the conversion of primary amine, but the reduction of primary amine is limited at the same equivalent and consumes secondary amine. Therefore, the preparation of polyaspartic ester containing low primary amine and high solid content usually takes weeks or even months, which greatly increases the production cost and is not conducive to market competition of the product. SUMMARY

[0005] The present application provides a synthesis method of polyaspartic ester, comprising the following steps:

[0006] S1, under the atmosphere of nitrogen, the dialkyl maleate is added dropwise into the alicyclic diamine at 40-60℃, and after the addition is completed, the temperature is kept for 1-3h;

[0007] S2, the temperature is raised to 80-90℃, and the reaction is kept for 24-48h, the solid content and the content of residual primary amine are determined, and the initial product is obtained;

[0008] S3, the initial product is continuously heated to 90-140℃, the lactone is added dropwise, and the temperature is kept for 6-12h, and the product is obtained.

[0009] Preferably, the solid content of the initial product is greater than 95wt%.

[0010] The dialkyl maleate includes one or more of dimethyl maleate, diethyl maleate, dibutyl maleate, and diisooctyl maleate.

[0011] The alicyclic diamine is one or more of cyclopentanediamine, isophorone diamine, 3,3'-dimethyl-4,4'-diamino-dicyclohexyl methane, and 4,4'-diamino-dicyclohexyl methane.

[0012] The molar ratio of the alicyclic diamine to the dialkyl maleate is (0.8-1.5):2.

[0013] The molar ratio of the lactone to the residual primary amine is (0.5-2):1.

[0014] The present applicant has found that the molar ratio of the lactone to the residual primary amine is (0.5-2):1, and the lactone includes a 3-9-membered ring lactone, which significantly shortens the time for the conversion of the residual primary amine into a secondary amine, and further significantly shortens the total time for the preparation of a low-primary-amine high-solid-content low-viscosity polyaspartic ester. It is speculated that the reason is that the oxygen atom on the carbonyl carbon in the ester is easily attacked by the nitrogen atom in the primary amine to form a temporary four-membered ring intermediate. The internal tension of the lactone is greater than that of the general ester, and it is easier to be attacked by the primary amine to open the ring to generate a hydroxyl amide. In addition, the secondary amine generated in the whole system is difficult to combine with the lactone due to the high steric hindrance effect, and thus the lactone and the primary amine can almost completely react in sufficient time.

[0015] Preferably, the molar ratio of the lactone to the residual primary amine is (1-2):1.

[0016] The lactone is one or more of propylene carbonate, ethylene carbonate, ethylidene carbonate, propylene lactone, butyrolactone, 1,3-propanesulfonic acid lactone, valerolactone, caprolactone, and heptalactone, etc. The number of the poly-membered ring of the lactone is 3-9.

[0017] The initial product can be F520, F420, NH 1520, and NH 1420 of any one of the models of products.

[0018] Preferably, the F520 and F420 are produced by Shenzhen Feiyangjun New Material Co., Ltd. NH 1520 and NH 1420 is produced by KOSO.

[0019] The second aspect of the present application provides a polyaspartic ester for use in the preparation of polyurea coating.

[0020] The third aspect of the present application provides a polyurea coating, comprising: color paint and curing agent; wherein the color paint comprises 30-60% of the polyaspartic ester of any one of claims 1-7, 0.2-0.8% of dispersant, 0.1-1.0% of defoaming agent, 0.1-0.3% of leveling agent, 0.3-1.0% of fumed silica, 5-10% of molecular sieve, and barium sulfate to make up the balance; and the curing agent is HDI trimer.

[0021] The mass ratio of the color paint to the curing agent is (20-25):(7.8-10).

[0022] Preferably, the HDI trimer comprises one or more of HT-100, HT-300 and HT-600.

[0023] The applicant has found that when the mass ratio of the color paint to the curing agent is (20-25):(7.8-10) and the curing agent is HDI trimer, the polyaspartic ester prepared has excellent wear resistance, flexibility and humidity sensitivity; the reason is that the polyaspartic ester is combined with the HDI trimer, the hardness of the paint film is very high, but the flexibility is insufficient. The hydroxyl amide generated after the ring opening of the lactone destroys the regularity of the whole molecule, and the long carbon chain generated promotes the increase of flexibility. On the other hand, the hydroxyl amide increases the molecular weight and increases the crosslinking density. At the same time, the reaction rate of the secondary amine in aspartic ester with isocyanate cannot completely prevent the reaction of water in the air or filler with isocyanate. The longer the curing time of the paint film, the more time the carbon dioxide generated by the reaction of water in the filler with isocyanate has to escape. The reduction of the reactivity in the polyaspartic ester will delay the curing time of the paint film, and thus improve the humidity sensitivity.

[0024] Beneficial effects

[0025] 1. This application uses a specific method for preparing polyaspartic esters to reduce residual primary amines from over 20 mg KOH / g to 1 mg KOH / g within 6-18 hours. The entire preparation time can be controlled between 40-60 hours, resulting in polyaspartic esters with low primary amine content, high solids content, and low viscosity.

[0026] 2. The molar ratio of the alicyclic diamine to the dialkyl maleate is (0.8–1.5):2, utilizing the alicyclic diamine.

[0027] A slight excess can improve the reaction efficiency, and polyaspartic acid ester with a solid content of more than 95 wt% can be obtained in 24-48 hours.

[0028] 3. The molar ratio of the lactone to the residual primary amine is (0.5-2):1, which significantly shortens the time for the residual primary amine to be converted into secondary amine, and thus significantly shortens the total time for preparing low-primary-amine, high-solids-content, low-viscosity polyaspartic acid ester.

[0029] 4. The lactone comprises 3-9 membered ring lactones, which results in a longer activation period for the prepared polyaspartic ester resin, potentially increasing the conversion rate of primary amines to secondary amines, and also introducing primary hydroxyl groups. Compared to primary amines, the converted secondary amines and the introduced primary hydroxyl groups exhibit lower reactivity with isocyanates.

[0030] 5. The mass ratio of the paint to the curing agent is (20-25):(7.8-10), and the curing agent is HDI trimer. The prepared polyaspartic acid ester has better wear resistance, flexibility and temperature and humidity sensitivity. Attached Figure Description

[0031] Figure 1 The synthesis steps of polyaspartic acid ester in Example 1 Detailed Implementation

[0032] Example 1

[0033] A method for synthesizing polyaspartic acid ester comprises the following steps:

[0034] like Figure 1 As shown, under nitrogen protection, at 50°C, diethyl maleate (2 mol) was added dropwise to 3,3'-dimethyl-4,4'-diamino-dicyclohexylmethane (1.05 mol). After reaction time T1, the solid content and residual primary amine content were measured. Then, an equimolar amount of caprolactone was added, and the reaction was carried out at 120°C for time T2. The solid content and primary amine content were measured again to obtain a low-primary-amine polyaspartic acid ester resin (named WW521).

[0035] An application of polyaspartic acid ester in the preparation of polyurea coatings.

[0036] Preparation of polyaspartic ester polyurea coating: WW521: dispersant (BYK-163): defoamer 1 (BYK-1790): defoamer 2 (Tego airex 900): leveling agent (TEGO-410 and BYK-354 in equal proportions): fumed silica (DM-10): molecular sieve (3A activated powder): barium sulfate: color paste (self-made by the company) = 45: 0.5: 0.3: 0.2: 0.1: 0.5: 5: 43.1: 5, mix WW521, dispersant, defoamer, leveling agent together by high-speed disperser, set the speed to 1000r / min, time for 10min. Then add fumed silica, molecular sieve, barium sulfate, color paste, set the speed to 2000r / min, time for 30min, to prepare WW521 color paint. Then according to the mass ratio of WW521 color paint: HDI trimer (HT-600) = 100: 34.29, after mixing, WW521 polyaspartic ester polyurea coating (referred to as WW521 polyurea) is obtained.

[0037] Example 2

[0038] A synthesis method of polyaspartic ester is as follows:

[0039] Under the protection of nitrogen, diethyl maleate (2 mol) is added dropwise at 50℃ in 3,3'-dimethyl-4,4'-diamino-dicyclohexyl methane (1.05 mol), after reaction T1 time, the solid content and the content of residual primary amine are determined, and twice the moles of caprolactone of the residual primary amine are added, and reacted at 120℃ for T2 time, and the solid content and the content of primary amine are determined, to obtain a low primary amine polyaspartic ester resin (named as WW522).

[0040] Application of polyaspartic ester in the preparation of polyurea coating.

[0041] Preparation of polyaspartic ester polyurea coating: WW522: dispersant (BYK-163): defoamer 1 (BYK-1790): defoamer 2 (Tego airex 900): leveling agent (TEGO-410 and BYK-354 in equal proportions): fumed silica (DM-10): molecular sieve (3A activated powder): barium sulfate: color paste (self-made by the company) = 45: 0.5: 0.3: 0.2: 0.1: 0.5: 5: 43.1: 5, mix WW522, dispersant, defoamer, leveling agent together with high-speed mixer, set the speed to 1000r / min, time for 10min. Then add fumed silica, molecular sieve, barium sulfate, color paste, set the speed to 2000r / min, time for 30min, to prepare WW522 color paint. Then according to the mass ratio of WW522 color paint: HDI trimer = 100: 34.29, after mixing, WW522 polyaspartic ester polyurea coating (referred to as WW522 polyurea) is obtained.

[0042] Example 3

[0043] A synthesis method of polyaspartic ester, comprising the following steps:

[0044] Under the protection of nitrogen, diethyl maleate (2 mol) is added dropwise at 50℃ in 3,3'-dimethyl-4,4'-diamino-dicyclohexyl methane (1.10 mol), after reaction T1 time, the solid content and the content of residual primary amine are determined, then the same molar of caprolactone as the residual primary amine is added, and reacted at 120℃ for T2 time, and the solid content and the content of primary amine are determined to obtain low primary amine polyaspartic ester resin (named as WW523).

[0045] Application of polyaspartic ester in preparation of polyurea coating.

[0046] Preparation of polyaspartic ester polyurea coating: according to the mass ratio WW523: dispersant (BYK-163): defoamer 1 (BYK-1790): defoamer 2 (Tego airex 900): leveling agent (TEG0-410 and BYK-354 in equal proportions): fumed silica (DM-10): molecular sieve (3A activated powder): barium sulfate: color paste (self-made by the company) = 45:0.5:0.3:0.2:0.1:0.5:5:43.1:5, mix WW523, dispersant, defoamer and leveling agent together by high-speed disperser, set the speed to 1000 r / min, and the time to 10 min. Then add fumed silica, molecular sieve, barium sulfate and color paste, set the speed to 2000 r / min, and the time to 30 min, to prepare WW523 color paint. Then mix WW523 color paint: HDI trimer = 100:34.29 by mass ratio to obtain WW523 polyaspartic ester polyurea coating (referred to as WW523 polyurea).

[0047] Example 4:

[0048] A method for synthesizing polyaspartic ester, comprising the following steps:

[0049] Determine the residual primary amine of F520, then add the same molar amount of caprolactone as the residual primary amine, and react at 120°C for T2 time to determine the solid content and primary amine content to obtain a low primary amine polyaspartic ester resin (named WW524). The F520 is produced by Shenzhen Feiyangjun New Material Co., Ltd.

[0050] Application of polyaspartic ester, applied to the preparation of polyurea coating.

[0051] Preparation of polyaspartic ester polyurea coating: according to the mass ratio WW524: dispersant (BYK-163): defoamer 1 (BYK-1790): defoamer 2 (Tego airex 900): leveling agent (TEG0-410 and BYK-354 in equal proportions): fumed silica (DM-10): molecular sieve (3A activated powder): barium sulfate: color paste (self-made by the company) = 45:0.5:0.3:0.2:0.1:0.5:5:43.1:5, mix WW524, dispersant, defoamer and leveling agent together by high-speed disperser, set the speed to 1000 r / min, and the time to 10 min. Then add fumed silica, molecular sieve, barium sulfate and color paste, set the speed to 2000 r / min, and the time to 30 min, to prepare WW524 color paint. Then mix WW524 color paint: HDI trimer = 100:34.29 by mass ratio to obtain WW524 polyaspartic ester polyurea coating (referred to as WW524 polyurea).

[0052] Comparative Example 1:

[0053] A method for synthesizing a polyaspartic ester comprises the following steps:

[0054] Preparation of polyaspartic ester resin: under nitrogen protection, diethyl maleate (2.02 mol) is added dropwise into 3,3'-dimethyl-4,4'-diamino-dicyclohexyl methane (1 mol) at 50°C, after reaction for a time T1, the solid content and the residual primary amine content are determined, and then the reaction is continued at 120°C for a time T2, the solid content and the primary amine content are determined, and a low-primary amine polyaspartic ester resin (named as WW531) is obtained.

[0055] Application of a polyaspartic ester to preparation of a polyurea coating.

[0056] Preparation of a polyaspartic ester polyurea coating: WW531, dispersant (BYK-163), defoamer 1 (BYK-1790), defoamer 2 (Tego airex 900), leveling agent (TEGO-410 and BYK-354 in equal proportions), fumed silica (DM-10), molecular sieve (3A activated powder), barium sulfate, and color paste (self-made by the company) are mixed at a mass ratio of 45:0.5:0.3:0.2:0.1:0.5:5:43.1:5, and then the WW531, dispersant, defoamer, and leveling agent are uniformly mixed by a high-speed disperser at a speed of 1000 r / min for 10 min. Then, the fumed silica, molecular sieve, barium sulfate, and color paste are added, and the mixture is mixed at a speed of 2000 r / min for 30 min to obtain a WW531 color paint. Then, the WW531 color paint and HDI trimer are mixed at a mass ratio of 100:34.29 to obtain a WW531 polyaspartic ester polyurea coating (referred to as WW531 polyurea).

[0057] Comparative Example 2:

[0058] A method for synthesizing a polyaspartic ester comprises the following steps:

[0059] Polyaspartic ester resin: the F520 polyaspartic ester is further reacted at 120°C for a time T2, and the solid content and the residual primary amine content are determined to obtain a low-primary amine polyaspartic ester resin (named as WW532). The F520 is produced by Shenzhen Feiyangjun New Material Co., Ltd.

[0060] Application of a polyaspartic ester to preparation of a polyurea coating.

[0061] Preparation of polyaspartic ester polyurea coating: WW532: dispersant (BYK-163): defoamer 1 (BYK-1790): defoamer 2 (Tego airex 900): leveling agent (TEGO-410 and BYK-354 in equal proportions): fumed silica (DM-10): molecular sieve (3A activated powder): barium sulfate: color paste (self-made by the company) = 45: 0.5: 0.3: 0.2: 0.1: 0.5: 5: 43.1: 5, mix WW532, dispersant, defoamer, leveling agent together by high-speed disperser, set the speed to 1000 r / min, time for 10 min. Then add fumed silica, molecular sieve, barium sulfate, color paste, set the speed to 2000 r / min, time for 30 min, to prepare WW532 color paint. Then according to the mass ratio of WW532 color paint: HDI trimer = 100: 34.29, after mixing, WW532 polyaspartic ester polyurea coating (referred to as WW532 polyurea) is obtained.

[0062] Comparative example 3:

[0063] A method for synthesizing polyaspartic ester, comprising the following steps:

[0064] Preparation of polyaspartic ester resin: under nitrogen protection, 50℃, drop maleic acid diethyl ester (2.02mol) into 3,3'-dimethyl-4,4'-diamino-dicyclohexyl methane (1mol), after reaction T1 time, measure the solid content and residual primary amine content, continue to react at room temperature for T2 time, measure the solid content and primary amine content, to obtain low primary amine polyaspartic ester resin (named as WW533).

[0065] Application of polyaspartic ester in preparation of polyurea coating.

[0066] Preparation of polyaspartic ester polyurea coating: WW533: dispersant (BYK-163): defoamer 1 (BYK-1790): defoamer 2 (Tego airex 900): leveling agent (TEGO-410 and BYK-354 in equal proportions): fumed silica (DM-10): molecular sieve (3A activated powder): barium sulfate: color paste (self-made by the company) = 45:0.5:0.3:0.2:0.1:0.5:5:43.1:5, mix WW533, dispersant, defoamer, leveling agent together by high-speed disperser, set the speed to 1000 r / min, time for 10 min. Then add fumed silica, molecular sieve, barium sulfate, color paste, set the speed to 2000 r / min, time for 30 min, to prepare WW533 color paint. Then according to the mass ratio of WW533 color paint: HDI trimer = 100:34.29, after mixing, WW533 polyaspartic ester polyurea coating (referred to as WW533 polyurea) is obtained.

[0067] Performance test method

[0068] 1. The polyaspartic ester synthesis parameters in the test examples and comparative examples are listed in Table 1.

[0069] 2. The performance of polyurea coating in the test examples and comparative examples is listed in Table 2.

[0070] Performance test data

[0071] Table 1

[0072]

[0073] Table 2

[0074]

[0075]

[0076] 1. From the above test results, it can be seen that the time required for preparing polyaspartic ester with high solid, low viscosity and low primary amine residue by conventional method is very long. After the treatment of lactone, the polyaspartic ester not only has a slightly larger viscosity, but also greatly shortens the reaction time, and the treated polyaspartic ester has more excellent performance, such as extending the activation period, improving the wear resistance, and improving the sensitivity to temperature and humidity, etc.

[0077] 2. From the above data, it can be seen that the time required for the preparation of the low primary amine polyaspartic acid ester resin is significantly shorter in Examples 1 to 4 than in Comparative Examples 1 to 3, and the primary amine residue obtained is lower. In Example 2, a polyaspartic acid ester having a primary amine residue of 1.0 mgKOH / g and a solid content of 92.6 wt% can be prepared in 40 h;

[0078] 3. From the above data, it can be seen that the activation period of the polyaspartic acid ester prepared after the improvement is extended (from 60 min to 70 min), and the activation period increases as the primary amine conversion rate increases.

[0079] 4. From the above data, it can be seen that the hardness and resistance of the polyaspartic acid ester prepared after the improvement are not deteriorated, the wear resistance can be improved to 0.0197, and there is no blistering in the 200 μm drawdown under high temperature and high humidity and low temperature and high humidity.

Claims

1. A method for synthesizing polyaspartic acid ester, characterized in that, Includes the following steps: S1, under a nitrogen atmosphere at 40-60℃, dialkyl maleate is added dropwise to alicyclic diamine. After the addition is complete, the mixture is kept at this temperature for 1-3 hours. S2, heat to 80-90℃ and keep the temperature for 24-48h, determine the solid content and residual primary amine content to obtain the initial product; S3, continue heating the initial product to 90-140℃, add polycyclic esters dropwise, and keep warm for 6-12 hours to obtain the final product; The polycyclic esters include one or more of propylene carbonate, ethylene carbonate, propiolactone, butyrolactone, 1,3-propanesulfonate lactone, valproic acid lactone, caprolactone, and heptanolactone.

2. The method for synthesizing polyaspartic acid ester according to claim 1, characterized in that, The dialkyl maleate esters include one or more of dimethyl maleate, diethyl maleate, dibutyl maleate, and diisooctyl maleate.

3. The method for synthesizing polyaspartic acid ester according to claim 2, characterized in that, The alicyclic diamine is one or more of cyclopentanediamine, isophoronediamine, 3,3'-dimethyl-4,4'-diamino-dicyclohexylmethane, and 4,4'-diamino-dicyclohexylmethane.

4. The method for synthesizing polyaspartic acid ester according to claim 3, characterized in that, The molar ratio of the alicyclic diamine to the dialkyl maleate is (0.8~1.5):

2.

5. The method for synthesizing polyaspartic acid ester according to claim 4, characterized in that, The molar ratio of the lactone to the residual primary amine is (0.5~2):

1.

6. A method for synthesizing polyaspartic acid ester according to claim 1 or 5, characterized in that, The primary product may also be composed of F520, F420, and Desmophen. ® NH 1520 and Desmophen ® Replacement for any model of NH 1420.

7. An application of a polyaspartic acid ester according to any one of claims 1-6, characterized in that, It is used in the preparation of polyurea coatings.

8. A polyurea coating, characterized in that, include: Paint and hardener; By weight percentage, the paint composition includes 30-60% polyaspartic acid ester as described in any one of claims 1-6, 0.2-0.8% dispersant, 0.1-1.0% defoamer, 0.1-0.3% leveling agent, 0.3-1.0% fumed silica, 5-10% molecular sieve, and barium sulfate to make up the balance; the curing agent is HDI trimer.

9. A polyurea coating according to claim 8, characterized in that, The mass ratio of the paint to the curing agent is (20~25):(7.8~10).

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