A method for reducing the amide content of a fatty primary amine
By adding silica to fatty primary amines and pretreating them with heat before distillation, the problem of high amide impurity content in fatty primary amines is solved, resulting in high-purity and high-yield fatty primary amine products suitable for various additive products.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- FENGYI FINE CHEM LIANYUNGANG
- Filing Date
- 2022-03-28
- Publication Date
- 2026-07-07
AI Technical Summary
Existing technologies are insufficient to effectively reduce the content of amide impurities in fatty primary amines, resulting in low product purity and yield, which affects their application in multiple fields.
Adding silica to fatty primary amines and pre-treating them by heating before distillation, followed by mixing thoroughly, heating and stirring, and then distilling again, improves the purity and yield of fatty primary amines.
It effectively reduces the amide impurity content in fatty primary amines to below 0.5%, improves product purity and yield to over 97%, and meets the application needs of multiple fields.
Abstract
Description
Technical Field
[0001] This application relates to the field of fine chemicals, specifically to a method for reducing the amide content in fatty primary amines. Background Technology
[0002] Aliphatic primary amines and their salts can be used as effective ore flotation agents, anti-caking agents for fertilizers or explosives, lubricant additives, bactericides in the petroleum industry, fuel and gasoline additives, electronic cleaning agents, emulsifiers, in the production of organometallic clays, pigment processing additives, water treatment agents, and molding agents. Furthermore, the adducts of aliphatic primary amines with ethylene oxide can be used as nonionic surfactants and antistatic agents in the plastics industry, making them important fine chemical products and intermediates.
[0003] The primary aliphatic amines synthesized by catalytic hydrogenation using fatty nitriles as raw materials contain a certain amount of amide impurities. These amide impurities reduce the purity of the product and have an adverse effect on the synthesis of ethoxylated products and other fields.
[0004] Because the boiling points of the impurity fatty amides are very close to those of the product fatty primary amines, simple distillation cannot reduce them to very low levels. Currently, the factory uses distillation, which can remove some amide impurities, but cannot achieve very low levels. Summary of the Invention
[0005] To address the above problems, the inventors of this invention have developed a method that effectively improves the yield and purity of fatty primary amines by adding silica to fatty primary amines containing fatty amide impurities, pre-treating them with heat, and then distilling them.
[0006] A first aspect of the present invention provides a method for purifying fatty primary amines, the method comprising the following steps:
[0007] (1) Add silica to a fatty primary amine containing fatty amide impurities and mix thoroughly to obtain a mixture;
[0008] (2) After heating and stirring the mixture, distill it to obtain purified fatty amines.
[0009] In one or more specific embodiments, the aliphatic primary amine in step (1) is one or more of a straight-chain or branched aliphatic primary amines containing 6-30 carbon atoms, preferably one or more of 8, 12, 16, and 18 carbon atoms.
[0010] In one or more specific embodiments, the fatty amide in step (1) is one or more of a straight-chain or branched aliphatic amides containing 6-30 carbon atoms, preferably one or more of 8, 12, 16, and 18 carbon atoms.
[0011] In one or more specific embodiments, in step (1), the content of fatty amide impurities is 0.3%-5%, preferably 1%-1.5%, based on the total weight of the fatty primary amines containing fatty amide impurities.
[0012] In one or more specific embodiments, the fatty primary amine in step (1) is synthesized by catalytic hydrogenation using fatty nitriles as raw materials.
[0013] In one or more specific embodiments, the silica in step (2) can be crystalline or amorphous, and can be a commercially available silica-containing product, such as commercially available silicone or pure silica. There are no special restrictions on the particle size of silica, and the selection can be made as needed. Preferably, the silica is in powder form.
[0014] In one or more specific embodiments, the amount of silica added in step (1) is 0.01%-5%, preferably 0.1%-1%, based on the total weight of the fatty primary amine containing fatty amide impurities.
[0015] In one or more specific embodiments, the heating temperature in step (2) is above 180°C, preferably 180-220°C, and the heating and stirring time is above 0.05 hours, preferably 0.1-5 hours, and more preferably 1-2 hours.
[0016] In one or more specific embodiments, the distillation in step (2) may be one or a combination of atmospheric distillation, vacuum distillation, batch distillation, and continuous distillation.
[0017] In one or more specific embodiments, the distillation in step (2) ends when there is no more distillate at the corresponding pressure and temperature.
[0018] In one or more specific embodiments, the content of amide impurities in the purified fatty primary amine in step (2) can be reduced to less than 0.5% based on the total weight of the purified fatty primary amine; more preferably, it can be reduced to less than 0.3%, and even more preferably, it can be reduced to less than 0.2%.
[0019] In one or more specific embodiments, the yield of fatty primary amines in step (2) is greater than 97%.
[0020] A second aspect of the present invention provides an additive product comprising the purified fatty primary amine product described in the first aspect of the present invention.
[0021] In one or more specific embodiments of the present invention, the additive products include ore flotation agents, fertilizer or explosive anti-caking agents, lubricating additives, petroleum industry bactericides, fuel and gasoline additives, electronic cleaning agents, emulsifiers, organometallic clay production, pigment processing additives, water treatment agents, molding agents, etc.
[0022] Technical effects:
[0023] This invention discloses a method for purifying fatty primary amines. Compared with existing technologies, it has the following advantages: it can effectively reduce the amide content in fatty primary amines and improve the purity and yield of fatty primary amines. Detailed Implementation
[0024] In this invention, unless otherwise specified, percentage (%) or parts refer to weight percentage or parts relative to the composition.
[0025] In this invention, unless otherwise specified, the components involved or their preferred components can be combined to form new technical solutions.
[0026] In this invention, unless otherwise specified, all embodiments and preferred embodiments mentioned herein can be combined to form new technical solutions.
[0027] In this invention, unless otherwise specified, all the technical features and preferred features mentioned herein can be combined to form new technical solutions.
[0028] In this invention, unless otherwise stated, the sum of the contents of each component in the composition is 100%.
[0029] In this invention, unless otherwise stated, the sum of the parts of each component in the composition may be 100 parts by weight.
[0030] In this invention, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" have been listed herein, and "0-5" is simply a shortened representation of these numerical combinations.
[0031] In this invention, unless otherwise specified, the integer range "ab" is a shortened representation of any combination of integers from a to b, where a and b are both integers. For example, the integer range "1-N" represents 1, 2...N, where N is an integer.
[0032] In this invention, unless otherwise stated, “combination of” means a multi-component mixture of the elements, such as two, three, four, and up to the maximum possible multi-component mixture.
[0033] Unless otherwise specified, the term "a" as used in this specification means "at least one".
[0034] Unless otherwise specified, all percentages (including weight percentages) mentioned in this invention are based on the total weight of the composition.
[0035] The “range” disclosed in this document takes the form of a lower limit and an upper limit. It can be one or more lower limits and one or more upper limits, respectively. A given range is defined by selecting a lower limit and an upper limit. The selected lower and upper limits define the boundaries of the particular range. All ranges that can be defined in this way are inclusive and composable; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60–120 and 80–110 are listed for a specific parameter, it is also expected that ranges of 60–110 and 80–120 are also expected. Furthermore, if the minimum range values are listed as 1 and 2, and if the maximum range values are listed as 3, 4, and 5, then the following ranges are all expected: 1–3, 1–4, 1–5, 2–3, 2–4, and 2–5.
[0036] In this paper, unless otherwise stated, all reactions were carried out at room temperature and pressure.
[0037] In this document, unless otherwise stated, the reaction steps may be performed sequentially or not in sequence. For example, other steps may be included between reaction steps, and the order of the reaction steps may be interchanged. Preferably, the reaction methods described herein are performed sequentially.
[0038] A purification method for fatty primary amines
[0039] A method for purifying fatty primary amines, the method comprising the following steps:
[0040] (1) Add silica to a fatty primary amine containing fatty amide impurities and mix thoroughly to obtain a mixture;
[0041] (2) After heating and stirring the mixture, distill it to obtain purified fatty amines.
[0042] In one or more specific embodiments, the aliphatic primary amine in step (1) is one or more of a straight-chain or branched aliphatic primary amines containing 6-30 carbon atoms, preferably one or more of 8, 12, 16, and 18 carbon atoms.
[0043] In one or more specific embodiments, the fatty amide in step (1) is one or more of a straight-chain or branched aliphatic amides containing 6-30 carbon atoms, preferably one or more of 8, 12, 16, and 18 carbon atoms.
[0044] In one or more specific embodiments, in step (1), the content of fatty amide impurities is 0.3%-5%, preferably 1%-1.5%, based on the total weight of the fatty primary amines containing fatty amide impurities.
[0045] In one or more specific embodiments, the fatty primary amine in step (1) is synthesized by catalytic hydrogenation using fatty nitriles as raw materials.
[0046] In one or more specific embodiments, the silica in step (2) can be crystalline or amorphous, and can be a commercially available silica-containing product, such as commercially available silicone or pure silica. There are no special restrictions on the particle size of silica, and the selection can be made as needed. Preferably, the silica is in powder form.
[0047] In one or more specific embodiments, the amount of silica added in step (1) is 0.01%-5%, preferably 0.1%-1%, based on the total weight of the fatty primary amine containing fatty amide impurities.
[0048] In one or more specific embodiments, the heating temperature in step (2) is above 180°C, preferably 180-220°C, and the heating and stirring time is above 0.05 hours, preferably 0.1-5 hours, and more preferably 1-2 hours.
[0049] In one or more specific embodiments, the distillation in step (2) may be one or a combination of atmospheric distillation, vacuum distillation, batch distillation, and continuous distillation.
[0050] In one or more specific embodiments, the distillation in step (2) ends when there is no more distillate at the corresponding pressure and temperature.
[0051] In one or more specific embodiments, the content of amide impurities in the purified fatty primary amine in step (2) can be reduced to less than 0.5% based on the total weight of the purified fatty primary amine; more preferably, it can be reduced to less than 0.3%, and even more preferably, it can be reduced to less than 0.2%.
[0052] In one or more specific embodiments, the yield of fatty primary amines in step (2) is greater than 97%.
[0053] Additive products
[0054] An additive product comprising the purified fatty primary amine product described in the first aspect of the present invention.
[0055] In one or more specific embodiments of the present invention, the additive products include ore flotation agents, fertilizer or explosive anti-caking agents, lubricating additives, petroleum industry bactericides, fuel and gasoline additives, electronic cleaning agents, emulsifiers, organometallic clay production, pigment processing additives, water treatment agents, molding agents, etc.
[0056] The raw materials used in the examples and comparative examples are as follows:
[0057] The fatty amine raw material used in the examples was provided by Clariant Wilmar Fatty Amines (Lianyungang) Co., Ltd.
[0058] The silica gel was purchased from Sinopharm Chemical Reagent Co., Ltd.
[0059] The activated carbon was purchased from Nanping Yuanli Activated Carbon Co., Ltd.
[0060] The main equipment used is as follows:
[0061] The experimental equipment consisted of standard glassware.
[0062] Detection methods
[0063] The concentration was detected by gas chromatography using an Agilent 7890A HP-5 capillary column, an FID detector, and helium as the carrier gas.
[0064] Examples 1-3, Comparative Examples 1-3
[0065] Example 1:
[0066] Take 100g of C12 fatty primary amine product and test its amide content, which is 1.1%. Place it in a 250ml glass flask, add 0.5g of silica powder (i.e., silica gel purchased from Sinopharm), heat to 200℃ and stir for 1 hour, then distill under reduced pressure, controlling the oil bath temperature at 130℃ and the system pressure at 10 mbar. Stop distillation when there is no more obvious distillate, obtaining 96.5g of fraction, with an amide content of 0.15%.
[0067] Example 2:
[0068] Take 100g of C8 fatty primary amine product and test its amide content, which is 1.0%. Place it in a 250ml glass flask, add 0.3g of silica powder (i.e., silica gel purchased from Sinopharm), heat to 180℃ and stir for 1 hour, then distill under reduced pressure, controlling the oil bath temperature at 80℃ and the system pressure at 15 mbar. Stop distillation when there is no more obvious distillate, obtaining 96.7g of fraction with an amide content of 0.22%.
[0069] Example 3:
[0070] Take 100g of a C16 / C18 mixed fatty primary amine product and test its amide content to be 1.5%. Place it in a 250ml glass flask, add 1g of silica powder (i.e., silica gel purchased from Sinopharm), heat to 220℃ and stir for 2 hours, then distill under reduced pressure, controlling the oil bath temperature at 145℃ and the system pressure at 1 mbar. Stop distillation when there is no more obvious distillate, and obtain 95.8g of fraction. The amide content of the obtained fraction is 0.11%.
[0071] Comparative Example 1:
[0072] Take 100g of the same C12 fatty primary amine product as in Example 1, with an amide content of 1.1%. Distill under reduced pressure under the same conditions as in Example 1 to obtain 96.8g of the fraction, which contains 0.9% amide.
[0073] Comparative Example 2:
[0074] Take 100g of the same C8 fatty primary amine product as in Example 2, with an amide content of 1.0%. Distill under reduced pressure under the same conditions as in Example 2 to obtain 97.2g of the fraction, which contains 0.8% amide.
[0075] Comparative Example 3:
[0076] Take 100g of the same C16 / C18 mixed fatty primary amine product as in Example 3, with an amide content of 1.5%. Perform vacuum distillation directly under the same conditions as in Example 3 to obtain 96.6g of the fraction, with an amide content of 1.2%.
[0077] Comparative Example 4:
[0078] Take 100g of the same C12 fatty primary amine product as in Example 1, with an amide content of 1.1%. Place it in a 250ml glass flask, add 0.5g of activated carbon powder, heat to 200°C and stir for 1 hour, then distill under reduced pressure using the same conditions as in Example 1, to obtain a fraction of 96.6g, with an amide content of 1.0%.
Claims
1. A method for purifying fatty primary amines, characterized in that, The method includes the following steps: (1) Add silica to a fatty primary amine containing fatty amide impurities and mix thoroughly to obtain a mixture; (2) After heating and stirring the mixture, distillation is carried out. The distillate is purified fatty primary amine. In step (2), the heating temperature is 180℃-220℃, the heating and stirring time is 1-2 hours, the content of fatty amide impurities is 0.3%-5%, and based on the total weight of the fatty primary amines containing fatty amide impurities, the amount of silica added in step (1) is 0.01%-5%. In step (1), the aliphatic primary amine is one or more of the following: a straight-chain or branched aliphatic primary amines containing 6-30 carbon atoms. In step (1), the fatty amide is one or more of the following: a straight-chain or branched aliphatic amides containing 6-30 carbon atoms.
2. The method as described in claim 1, characterized in that, The method also satisfies the following condition: (1) In step (1), the content of fatty amide impurities is 1%-1.5% based on the total weight of the primary fatty amines; (2) In step (1), the fatty primary amine is synthesized by catalytic hydrogenation using fatty nitriles as raw materials.
3. The method as described in claim 2, characterized in that, The aliphatic primary amine has one or more carbon atoms selected from 8, 12, 16, and 18.
4. The method as described in claim 2, characterized in that, The fatty amide has one or more carbon atoms selected from 8, 12, 16, and 18.
5. The method as described in claim 2, characterized in that, In step (1), the silicon dioxide is in powder form.
6. The method according to any one of claims 1-5, characterized in that, The amount of silica added in step (1) is 0.1%-1% based on the total weight of the fatty primary amine containing fatty amide impurities.
7. The method as described in claim 6, characterized in that, In step (2), distillation can be carried out using one or a combination of atmospheric distillation, vacuum distillation, batch distillation, and continuous distillation.
8. The method as described in claim 6, characterized in that, Based on the total weight of the purified fatty primary amine, the content of amide impurities in the purified fatty primary amine in step (2) can be reduced to below 0.5%.
9. The method as described in claim 8, characterized in that, Based on the total weight of the purified fatty primary amine, the content of amide impurities in the purified fatty primary amine in step (2) can be reduced to below 0.3%.
10. The method as described in claim 8, characterized in that, Based on the total weight of the purified fatty primary amine, the content of amide impurities in the purified fatty primary amine in step (2) can be reduced to below 0.2%.