A method for synthesizing N,N'-ethylene bis stearamide

Abstract

The application discloses a synthesis method of N,N'-ethylene bis-stearamide, and uses stearic acid and ethylenediamine as raw materials, and uses a titanium coupling agent containing a phosphite group or a pyrophosphoric acid ester group as a catalyst to synthesize N,N'-ethylene bis-stearamide. The titanium coupling agent catalyst used in the application not only has excellent catalytic performance on the reaction of synthesizing ethylene bis-stearamide, but also can prevent the synthesized ethylene bis-stearamide from being oxidized, and improves the yield, purity and whiteness of the product.

Description

Technical Field

[0001] This invention relates to a method for synthesizing N,N'-ethylene bis-stearamide, belonging to the field of chemical technology. Background Technology

[0002] N,N'-Ethylene bis-stearamide, also known as ethylene bis-stearamide, is a fatty acid bisamide compound. It is a multifunctional processing aid used as an internal and external lubricant, defoamer, dispersant, antistatic agent, and pore-forming agent, with extremely wide applications in industrial production, especially in various polymer materials and wood-plastic composites. EBS is harmless to humans and organisms and can also be used as a food packaging material, additive, and auxiliary agent. Most N,N'-Ethylene bis-stearamide manufacturers produce it through a two-step reaction of stearic acid and amine compounds, involving neutralization to form a salt and catalytic dehydration. The catalyst itself has oxidizing capabilities, easily oxidizing the material. However, the reaction temperature is relatively high, generally around 200℃. To prevent oxidation, suitable antioxidants are usually added, and the reaction is carried out under inert gas protection. However, the whiteness, purity, and yield of the product still need improvement; and the addition of antioxidants still affects the purity of N,N'-Ethylene bis-stearamide. Summary of the Invention

[0003] In response to at least one problem existing in the prior art, the present invention provides a method for synthesizing N,N'-ethylene bis-stearamide.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: a method for synthesizing N,N'-ethylene bis-stearamide, using stearic acid and ethylenediamine as raw materials, and a titanium coupling agent containing phosphite ester group or pyrophosphate ester group as catalyst to synthesize N,N'-ethylene bis-stearamide.

[0005] Preferably, the process of synthesizing N,N'-ethylenebisstearamide also includes anhydrous magnesium sulfate, which absorbs the water produced to promote the synthesis reaction.

[0006] Preferably, the titanium coupling agent is one of tetraisopropyl di(dioctylphosphite)titanate, tetraneoalkoxybis(decylphosphite)titanate, neoalkoxytris(dioctylpyrophosphite)titanate, or tetraoctyloxybis(dilaurylphosphite)titanate.

[0007] Preferably, the titanium coupling agent is one of tetraisopropyl di(dioctylphosphite)titanate or tetraneoalkoxy bis(didecylphosphite)titanate.

[0008] Preferably, the titanium coupling agent is tetraisopropyl di(dioctylphosphite)titanate.

[0009] Preferably, the molar ratio of stearic acid to ethylenediamine is 2:1.17~1.18, more preferably 2:1.175.

[0010] Preferably, the amount of titanium coupling agent added is 0.8 to 1.2% of the weight of stearic acid.

[0011] Preferably, in the synthesis of N,N'-ethylene bis-stearamide, the catalytic synthesis reaction temperature is 185~190℃ and the reaction time is 4~6h.

[0012] Preferably, the molar ratio of anhydrous magnesium sulfate to stearic acid is 0.35~0.5:1.

[0013] Preferably, the method for synthesizing N,N'-ethylene bis-stearamide includes the following steps:

[0014] (1) Under a nitrogen protective atmosphere, add stearic acid and anhydrous magnesium sulfate, and heat to 95~100℃;

[0015] (2) Add ethylenediamine to the reaction system of step (1) and react for 1.5~2 h;

[0016] (3) Add a titanium coupling agent containing phosphite ester group or pyrophosphate ester group as a catalyst to the reaction system of step (2), and continue to heat to 185~190℃ and catalyze the reaction for 4~6h;

[0017] (4) After cooling the reaction system of step (3) to 95~100℃, filter it, dissolve it in water, filter it again, and wash it to obtain N,N'-ethylene bis-stearamide.

[0018] The beneficial effects of this invention are as follows: The titanium coupling agent catalyst used in this invention has both Lewis acid and phosphite groups or Lewis acid and pyrophosphate groups. In addition to having good affinity for the raw material stearic acid, it not only has excellent catalytic performance for the synthesis of ethylene bis-stearamide, but also prevents the synthesized ethylene bis-stearamide from being oxidized. The synthesis process conditions of this invention are suitable, and combined with the titanium coupling agent catalyst containing phosphite or pyrophosphate groups, it effectively improves the yield, purity, and whiteness of the product. The synthesis of this invention does not require the addition of antioxidants, ensuring the whiteness of the product while improving its purity. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. The described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents, instruments, or components are not specified, they are all conventional products that can be purchased commercially.

[0020] Example 1

[0021] A method for synthesizing N,N'-ethylene bis-stearamide includes the following steps:

[0022] (1) Nitrogen gas is introduced into the reactor to replace the air. Under the nitrogen protective atmosphere, 142.25 g of stearic acid and 21.07 g of anhydrous magnesium sulfate are added, and the temperature is raised to 95~100℃.

[0023] (2) Add 35.1 g of ethylenediamine to the reaction system of step (1) and react for 2 h;

[0024] (3) Add 11.38 g of tetraisopropyl di(dioctylphosphite)titanate as a catalyst to the reaction system of step (2), and continue to heat to 185~190℃ for 6 h of catalytic reaction;

[0025] (4) After cooling the reaction system of step (3) to 95~100℃, filter to remove the remaining mixture of stearic acid, ethylenediamine and catalyst. Then dissolve the magnesium sulfate hydrate in pure water, filter to remove the water liquid, and wash with 95% ethanol to obtain 291.16g of N,N'-ethylenebisstearamide with a yield of 98.20%, a melting range of 142~145℃, an acid value of 4.72mgKOH / g, and a color value of 4.

[0026] Example 2

[0027] A method for synthesizing N,N'-ethylene bis-stearamide is the same as that in Example 1, except that 14.225 g of tetraisopropyl di(dioctylphosphite)titanate is used as a catalyst; the rest are the same.

[0028] 292.35 g of N,N'-ethylenebis-stearamide was obtained, with a yield of 98.60%, a melting range of 142.5~144℃, an acid value of 4.28 mgKOH / g, and a color value of 3.

[0029] Example 3

[0030] A method for synthesizing N,N'-ethylene bis-stearamide is the same as that in Example 1, except that 17.07 g of tetraisopropyl di(dioctylphosphite)titanate is used as a catalyst; the rest are the same.

[0031] 291.46 g of N,N'-ethylenebis-stearamide was obtained, with a yield of 98.30%, a melting range of 141.5~144℃, an acid value of 4.22 mgKOH / g, and a color value of 3.5.

[0032] Example 4

[0033] A method for synthesizing N,N'-ethylene bis-stearamide includes the following steps:

[0034] (1) Nitrogen gas is introduced into the reactor to replace the air. Under the nitrogen protective atmosphere, 142.25 g of stearic acid and 24.08 g of anhydrous magnesium sulfate are added, and the temperature is raised to 95~100℃.

[0035] (2) Add 35.1 g of ethylenediamine to the reaction system of step (1) and react for 2 h;

[0036] (3) Add 14.225 g of tetraisopropyl di(dioctylphosphite)titanate as a catalyst to the reaction system of step (2), and continue to heat to 185~190℃ for 5 h of catalytic reaction;

[0037] (4) After cooling the reaction system of step (3) to 95~100℃, filter to remove the remaining liquid mixture of stearic acid, ethylenediamine and catalyst. Then dissolve it in pure water to dissolve magnesium sulfate hydrate, filter to remove water liquid, and then wash with 95% ethanol to obtain 293.53g of N,N'-ethylenebisstearamide, with a yield of 99.0%, a melting range of 143~144℃, an acid value of 4.07mgKOH / g, and a color value of 3.

[0038] Example 5

[0039] A method for synthesizing N,N'-ethylene bis-stearamide is the same as that in Example 4, except that 11.38 g of tetraisopropyl di(dioctylphosphite)titanate is used as a catalyst; the rest are the same.

[0040] 292.64 g of N,N'-ethylenebis-stearamide was obtained, with a yield of 98.70%, a melting range of 142.5~144℃, an acid value of 4.18 mgKOH / g, and a color value of 3.

[0041] Example 6

[0042] A method for synthesizing N,N'-ethylene bis-stearamide is the same as that in Example 4, except that 17.07 g of tetraisopropyl di(dioctylphosphite)titanate is used as a catalyst; the rest are the same.

[0043] 293.1 g of N,N'-ethylenebis-stearamide was obtained, with a yield of 98.85%, a melting range of 143~144℃, an acid value of 4.09 mgKOH / g, and a color value of 3.

[0044] Example 7

[0045] A method for synthesizing N,N'-ethylenebis-stearamide is the same as that in Example 4, except that: 30.1 g of anhydrous magnesium sulfate is used; the rest is the same.

[0046] 292.94 g of N,N'-ethylenebis-stearamide was obtained, with a yield of 98.80%, a melting range of 143~144.5℃, an acid value of 4.16 mgKOH / g, and a color value of 3.

[0047] Example 8

[0048] A method for synthesizing N,N'-ethylenebisstearamide is the same as that in Example 4, except that the catalyst is tetraneoalkoxybis(dicepylphosphite)titanate; the rest are the same.

[0049] 290.85 g of N,N'-ethylenebis-stearamide was obtained, with a yield of 98.09%, a melting range of 142~144℃, an acid value of 5.13 mgKOH / g, and a color value of 3.5.

[0050] Example 9

[0051] A method for synthesizing N,N'-ethylene bis-stearamide is the same as that in Example 4, except that the catalyst is neoalkoxytris(dioctylpyrophosphoryloxy)titanate; the rest are the same.

[0052] 289.08 g of N,N'-ethylenebis-stearamide was obtained, with a yield of 97.50%, a melting range of 141~145℃, an acid value of 5.57 mgKOH / g, and a color value of 5.

[0053] Example 10

[0054] A method for synthesizing N,N'-ethylene bis-stearamide is the same as that in Example 4, except that the catalyst is tetraoctoxybis(dilaurylphosphite)titanate; the rest are the same.

[0055] 287.9 ​​g of N,N'-ethylenebis-stearamide was obtained, with a yield of 97.10%, a melting range of 141.5~144.5℃, an acid value of 5.25 mgKOH / g, and a color value of 4.5.

[0056] Comparative Example 1

[0057] A method for synthesizing N,N'-ethylene bis-stearamide is the same as that in Example 4, except that the catalyst is neoalkoxytris(diisooctylphosphoyloxy)titanate; the rest are the same.

[0058] 288.7 g of N,N'-ethylenebis-stearamide was obtained, with a yield of 97.37%, a melting range of 141~146℃, an acid value of 5.38 mgKOH / g, and a color value of 13.

[0059] Compared with Example 4, the product of Comparative Example 1 has a higher color value, poorer whiteness, wider melting range, and lower purity.

[0060] Comparative Example 2

[0061] A method for synthesizing N,N'-ethylene bis-stearamide is the same as that in Example 4, except that the reaction temperature is 200~210℃; otherwise, they are the same.

[0062] 293.5 g of N,N'-ethylenebis-stearamide was obtained, with a yield of 98.99%, a melting range of 142~144℃, an acid value of 5.38 mgKOH / g, and a color value of 6.

[0063] Compared with Example 4, the product of Comparative Example 2 has a higher color value, a deeper color, poorer whiteness, a wider melting range, and lower purity.

[0064] Comparative Example 3

[0065] A method for synthesizing N,N'-ethylenebis-stearamide is the same as that in Example 4, except that 34.95 g of ethylenediamine is used; the rest are the same.

[0066] 288.1 g of N,N'-ethylenebis-stearamide was obtained, with a yield of 97.17%, a melting range of 138~140℃, an acid value of 4.11 mgKOH / g, and a color value of 3.

[0067] Compared with Example 4, Comparative Example 2 has a lower melting range and does not meet the requirements.

[0068] Comparative Example 4

[0069] A method for synthesizing N,N'-ethylenebis-stearamide is the same as that in Example 4, except that: 35.55 g of ethylenediamine is used; the rest are the same.

[0070] 287.0 g of N,N'-ethylenebisstearamide was obtained, with a yield of 96.80%, a melting range of 143.5~145℃, an acid value of 7.28 mgKOH / g, and a color value of 3.

[0071] Compared with Example 4, Comparative Example 2 has a higher acid value, which does not meet the requirements.

[0072] Comparative Example 5

[0073] A method for synthesizing N,N'-ethylenebis-stearamide is the same as that in Example 4, except that anhydrous magnesium sulfate is not added; otherwise, they are the same.

[0074] 275.2 g of N,N'-ethylenebis-stearamide was obtained, with a yield of 92.82%, a melting range of 142~145℃, an acid value of 6.1 mgKOH / g, and a color value of 3.5.

[0075] The yield of Comparative Example 2 was lower than that of Example 4.

[0076] Based on the results of Examples 1-10 and Comparative Examples 1-5 above, the titanium coupling agent catalyst containing phosphite groups or pyrophosphates involved in this invention not only possesses excellent catalytic performance but also prevents the oxidation of the synthesized ethylene bis-stearamide. The synthesis process conditions of this invention are suitable, effectively improving the yield, purity, and whiteness of the product. Compared with the prior art, the synthesis of this invention does not require the addition of antioxidants, ensuring product whiteness while improving product purity and yield.

[0077] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit and essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0078] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for synthesizing N,N'-ethylenebis-stearamide, characterized in that, N,N'-ethylenebis-stearamide was synthesized using stearic acid and ethylenediamine as raw materials and titanium coupling agents containing phosphite or pyrophosphate groups as catalysts. The titanium coupling agent is one of tetraisopropyl di(dioctylphosphite)titanate, tetraneoalkoxybis(decylphosphite)titanate, neoalkoxytris(dioctylpyrophosphite)titanate or tetraoctyloxybis(dilaurylphosphite)titanate.

2. The method for synthesizing N,N'-ethylenebis-stearamide according to claim 1, characterized in that, The titanium coupling agent is one of tetraisopropyl di(dioctylphosphite) titanate or tetraneoalkoxy bis(didecylphosphite) titanate.

3. The method for synthesizing N,N'-ethylenebis-stearamide according to claim 1, characterized in that, The titanium coupling agent is tetraisopropyl di(dioctylphosphite)titanate.

4. The method for synthesizing N,N'-ethylenebis-stearamide according to claim 1, characterized in that, The molar ratio of stearic acid to ethylenediamine is 2:1.17~1.

18.

5. The method for synthesizing N,N'-ethylenebis-stearamide according to claim 1, characterized in that, The amount of titanium coupling agent added is 0.8 to 1.2% of the weight of stearic acid.

6. The method for synthesizing N,N'-ethylene bis-stearamide according to claim 1, characterized in that, In the synthesis of N,N'-ethylene bis-stearamide, the catalytic synthesis reaction temperature is 185~190℃ and the reaction time is 4~6h.

7. The method for synthesizing N,N'-ethylenebis-stearamide according to claim 1, characterized in that, The synthesis of N,N'-ethylenebis-stearamide also includes anhydrous magnesium sulfate.

8. The method for synthesizing N,N'-ethylenebis-stearamide according to claim 7, characterized in that, The molar ratio of anhydrous magnesium sulfate to stearic acid is 0.35~0.5:

1.

9. The method for synthesizing N,N'-ethylenebis-stearamide according to any one of claims 1 to 8, characterized in that, The method for synthesizing N,N'-ethylene bis-stearamide includes the following steps: (1) Under a nitrogen protective atmosphere, add stearic acid and anhydrous magnesium sulfate, and heat to 95~100℃; (2) Add ethylenediamine to the reaction system of step (1) and react for 1.5~2 h; (3) Add a titanium coupling agent containing phosphite ester group or pyrophosphate ester group as a catalyst to the reaction system of step (2), and continue to heat to 185~190℃ and catalyze the reaction for 4~6h; (4) Cool the reaction system of step (3) to 95~100℃, then filter, dissolve in water, filter again, and wash to obtain N,N'-ethylene bis-stearamide.