CN109503395B - Stable choline solution and preparation method thereof - Google Patents
Stable choline solution and preparation method thereof Download PDFInfo
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- CN109503395B CN109503395B CN201811594587.8A CN201811594587A CN109503395B CN 109503395 B CN109503395 B CN 109503395B CN 201811594587 A CN201811594587 A CN 201811594587A CN 109503395 B CN109503395 B CN 109503395B
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- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C213/00—Preparation of compounds containing amino and hydroxy, amino and etherified hydroxy or amino and esterified hydroxy groups bound to the same carbon skeleton
- C07C213/10—Separation; Purification; Stabilisation; Use of additives
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C213/00—Preparation of compounds containing amino and hydroxy, amino and etherified hydroxy or amino and esterified hydroxy groups bound to the same carbon skeleton
- C07C213/04—Preparation of compounds containing amino and hydroxy, amino and etherified hydroxy or amino and esterified hydroxy groups bound to the same carbon skeleton by reaction of ammonia or amines with olefin oxides or halohydrins
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C215/00—Compounds containing amino and hydroxy groups bound to the same carbon skeleton
- C07C215/02—Compounds containing amino and hydroxy groups bound to the same carbon skeleton having hydroxy groups and amino groups bound to acyclic carbon atoms of the same carbon skeleton
- C07C215/40—Compounds containing amino and hydroxy groups bound to the same carbon skeleton having hydroxy groups and amino groups bound to acyclic carbon atoms of the same carbon skeleton with quaternised nitrogen atoms bound to carbon atoms of the carbon skeleton
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Abstract
The invention relates to a stable choline solution and a preparation method thereof, belonging to the technical field of chemical synthesis. The stable choline solution contains choline hydroxide, water and choline carbonate, does not contain metal ions, has stable properties, and is an excellent non-metal strong base for cleaning a circuit board. The preparation method comprises the steps of firstly adding trimethylamine into water, uniformly stirring, introducing a certain amount of carbon dioxide, and stirring while adding to obtain a solution containing trimethyl ammonium carbonate; adding ethylene oxide into the solution, cooling and filtering to obtain the stable choline solution. The preparation method does not use toxic and harmful substances, avoids the emission of Volatile Organic Compounds (VOC) in the production process, does not use catalysts, and has mild reaction conditions. The choline carbonate is used as a stabilizer, so that the side reaction is obviously eliminated, other substances are not introduced, the production process is stable and safe, and the choline carbonate has wide application value in the fields of circuit board cleaning agents, material preparation, electrochemistry, organic synthesis and the like.
Description
Technical Field
The invention relates to a choline solution and a preparation method thereof, in particular to a stable choline solution and a preparation method thereof, and belongs to the technical field of chemical synthesis.
Background
Choline hydroxide, (CH)3)3N(OH)CH2CH2OH, also known as hydroxyethyl trimethylamine hydroxide or (2-hydroxyethyl) trimethylammonium hydroxide, is an organic strong base and is widely applied to the fields of material preparation, electrochemistry, organic synthesis and the like. In the manufacturing and cleaning process of the electronic circuit board, a cleaning agent is needed to remove rosin-based soldering flux, a small amount of residual soldering flux, water-soluble soldering flux, uncured soldering paste and residues of components on a surface-mounted component and a packaging component, and choline hydroxide is used as an inorganic nonmetal strong base, does not generate volatile pollutants in the application process of the cleaning agent, and does not influence the quality of the circuit board due to the fact that the choline hydroxide contains metal ions.
Choline hydroxide is an unstable hofmann base, and hofmann elimination easily occurs in an aqueous environment, and the choline hydroxide is decomposed into a plurality of byproducts such as olefine aldehyde polymers, and the like, so that the color becomes dark, precipitates are formed in a choline solution, and the change is volatile, strong smell and the like. The degradation reaction degrades the quality of the choline hydroxide solution, so how to prepare a stable choline hydroxide solution is a key technology for improving the application of the choline hydroxide solution.
In the prior art, a stabilizer is added to overcome adverse effects caused by side reactions, the stabilizer is generally used for treating acetaldehyde released by Hofmann elimination reaction, and the acetaldehyde is removed by 'scavenging' to remove reactants necessary for aldol condensation of a subsequent colored polymer. Substances which react with acetaldehyde, readily reduce acetaldehyde or destructively copolymerize with acetaldehyde, such as formaldehyde, hydroxylamine, semicarbazide and sulfites, are good stabilizers for choline hydroxide solutions.
US patent US 4686002 discloses the preparation of a stabilized choline hydroxide composition by adding a stabilized concentrate of formaldehyde to an aqueous choline hydroxide composition. The use of formaldehyde, hydroxylamine and semicarbazide has been limited due to toxicity and environmental pollution problems. US patent US 429491 discloses the preparation of a stabilized choline hydroxide composition by adding a stabilized concentrate of sulfite to an aqueous choline hydroxide composition. The sulfite generally needs to be effective at higher concentrations because the concentrated choline base solution turns black in a shorter time due to its lower solubility in the concentrated choline base solution.
In addition, borohydrides and alanates can reduce acetaldehyde to the corresponding alcohol and can reduce the conjugated enal polymer to the corresponding alcohol, with some reduction of the conjugated polyene function also occurring. But a large amount of hydrogen is released during the reaction process, so that safety risk exists.
Therefore, it is necessary to add a safe and nontoxic choline hydroxide solution and a method for preparing the same to minimize or eliminate adverse effects caused by side reactions.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention provides the stable choline solution which is easy to obtain raw materials, stable in reaction, green, environment-friendly and high in safety and the preparation method thereof.
In order to achieve the purpose, the technical scheme adopted by the invention for solving the technical problems is as follows:
a stabilized choline solution characterized by: comprising choline hydroxide, water and choline carbonate.
Preferably, the concentration of the choline carbonate in the choline solution is 15-20%.
A method for preparing a stabilized choline solution comprising the steps of:
1) adding trimethylamine into water, stirring and mixing, introducing carbon dioxide, stirring while adding, wherein the pressure is less than 2kgf/cm2Obtaining an aqueous solution containing trimethylamine and trimethyl ammonium carbonate at the temperature of 10-40 ℃;
2) adding ethylene oxide, trimethylamine, ethylene oxide and water into the aqueous solution prepared in the step to react to generate choline hydroxide; trimethyl ammonium carbonate, ethylene oxide and water react to generate choline carbonate; and cooling and filtering to obtain the stable choline solution.
Preferably, the molar ratio of trimethylamine to carbon dioxide in step 1) is trimethylamine to carbon dioxide =8.5 to 10: 1.
Preferably, the trimethylamine used in the step 1) is a trimethylamine aqueous solution with a concentration of 40-50% or liquefied trimethylamine with a purity of 99%.
Preferably, the molar ratio of ethylene oxide in step 2) to trimethylamine in step 1) is ethylene oxide to trimethylamine =1: 1.
Preferably, the temperature reduction in the step 2) is reduced to 30-60 ℃.
Preferably, the temperature reduction in the step 2) is cooling water temperature reduction or ice water circulation cooling temperature reduction.
Preferably, the ethylene oxide is added in the step 2) when the temperature is 30-60 ℃.
Preferably, the ethylene oxide described in step 2) is liquefied ethylene oxide at a concentration of 99%.
The invention has the beneficial technical effects that:
(1) the stable choline solution and the preparation method thereof do not use toxic and harmful substances, avoid the emission of Volatile Organic Compounds (VOC) in the production process, do not use catalysts, and have mild reaction conditions.
(2) The stable choline solution and the preparation method thereof take choline carbonate as a stabilizer, obviously eliminate side reactions, do not introduce other substances, and have stable and safe process.
(3) The stable choline solution and the preparation method thereof are economical, safe, green and environment-friendly, and the prepared choline solution has good stability and wide potential application value in the fields of circuit board cleaning agents, material preparation, electrochemistry, organic synthesis and the like.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without any inventive work belong to the protection scope of the present invention, and the detailed description does not limit the present invention.
Example 1:
75.83kg of liquefied trimethylamine having a purity of 99% and 105.24kg of water were added to a reaction vessel, and 5.94kg of carbon dioxide was introduced thereinto under stirring at a pressure of less than 2kgf/cm2Obtaining an aqueous solution containing trimethylamine and trimethyl ammonium carbonate at the temperature of 10 ℃; when the temperature is 30 ℃, 56.44kg of 99 percent liquefied ethylene oxide is added, and trimethylamine, ethylene oxide and water react to generate choline hydroxide; trimethyl ammonium carbonate, ethylene oxide and water react to generate choline carbonate; cooling the cooling water to 30 ℃, and filtering to obtain the stable choline solution. The choline carbonate concentration in the obtained choline solution was 15%, and the choline hydroxide concentration was 50%.
Example 2:
86.58kg of liquefied trimethylamine with a purity of 99% and 143.25kg of water were added to a reaction vessel, and 9.94kg of carbon dioxide was introduced thereto under stirring at a pressure of less than 2kgf/cm2Obtaining an aqueous solution containing trimethylamine and trimethyl ammonium carbonate at the temperature of 20 ℃; 64.44 kg of 99 percent liquefied ethylene oxide is added when the temperature is 40 ℃, and trimethylamine, ethylene oxide and water react to generate choline hydroxide; trimethyl ammonium carbonate, ethylene oxide and water react to generate choline carbonate; cooling to 35 deg.C with ice water circulation, and filtering to obtain stable bladderAn alkaline solution. The choline carbonate concentration in the obtained choline solution is 20%, and the choline hydroxide concentration is 40%.
Example 3:
189.58kg of a 40% aqueous trimethylamine solution was added to the reaction vessel, and 5.94kg of carbon dioxide was introduced thereinto under stirring at a pressure of less than 2kgf/cm2Obtaining an aqueous solution containing trimethylamine and trimethyl ammonium carbonate at the temperature of 30 ℃; when the temperature is 50 ℃, 56.44kg of 99 percent liquefied ethylene oxide is added, and trimethylamine, ethylene oxide and water react to generate choline hydroxide; trimethyl ammonium carbonate, ethylene oxide and water react to generate choline carbonate; cooling the cooling water to 40 ℃, and filtering to obtain the stable choline solution. The choline carbonate concentration in the obtained choline solution was 15%, and the choline hydroxide concentration was 50%.
Example 4:
151.66kg of a 50% aqueous trimethylamine solution and 29.41kg of water were added to a reaction vessel, and 5.94kg of carbon dioxide was introduced thereinto under stirring at a pressure of less than 2kgf/cm2Obtaining an aqueous solution containing trimethylamine and trimethyl ammonium carbonate at the temperature of 40 ℃; when the temperature is 60 ℃, 56.44kg of 99 percent liquefied ethylene oxide is added, and trimethylamine, ethylene oxide and water react to generate choline hydroxide; trimethyl ammonium carbonate, ethylene oxide and water react to generate choline carbonate; cooling the cooling water to 50 ℃, and filtering to obtain the stable choline solution. The choline carbonate concentration in the obtained choline solution was 15%, and the choline hydroxide concentration was 50%.
Example 5:
155.24kg of a 50% aqueous trimethylamine solution was added to the reaction vessel, and 6.6kg of carbon dioxide was introduced thereto under stirring at a pressure of less than 2kgf/cm2Obtaining an aqueous solution containing trimethylamine and trimethyl ammonium carbonate at the temperature of 40 ℃; when the temperature is 60 ℃, 57.78 kg of 99 percent liquefied ethylene oxide is added, and trimethylamine, ethylene oxide and water react to generate choline hydroxide; trimethyl ammonium carbonate, ethylene oxide and water react to generate choline carbonate; and cooling to 60 ℃ by ice water circulation cooling, and filtering to obtain the stable choline solution. The choline carbonate concentration in the obtained choline solution was 18.5%, and the choline hydroxide concentration was 55%.
Example 6:
73.20kg of liquefied trimethylamine having a purity of 99% and 70.52kg of water were charged into a reaction vessel, and 4.97kg of carbon dioxide was introduced thereinto under stirring at a pressure of less than 2kgf/cm2Obtaining an aqueous solution containing trimethylamine and trimethyl ammonium carbonate at the temperature of 10 ℃; when the temperature is 50 ℃, 54.49kg of 99 percent liquefied ethylene oxide is added, and trimethylamine, ethylene oxide and water react to generate choline hydroxide; trimethyl ammonium carbonate, ethylene oxide and water react to generate choline carbonate; cooling the cooling water to 50 ℃, and filtering to obtain the stable choline solution. The choline carbonate concentration in the obtained choline solution is 15%, and the choline hydroxide concentration is 60%.
And (4) comparing the results:
stability testing of the stabilized Choline solutions of the invention
The stability of the choline solutions prepared in examples 1 to 6 above was tested, respectively, and the following were used: the stability performance comparison was performed as comparative examples 1 to 5, in which a choline hydroxide solution having a concentration of 50% without adding a stabilizer, a choline hydroxide solution having a concentration of 60% with 1000ppm of sodium dithionite, a choline hydroxide solution having a concentration of 60% with 1000ppm of sodium sulfite, and a pure choline hydroxide solution having a concentration of 60% with 1000ppm of benzaldehyde were added.
The test method comprises the following steps: the choline solutions prepared in the above examples 1 to 6 and comparative examples 1 to 5 were covered with nitrogen gas, and APHA measurement was performed by a luvibond colorimeter having a quartz cuvette with a diameter of 5 cm.
Chroma was judged by visual assessment through a 4cm path length based on a scale of 0-4, 0 being clear and water white (APHA < 20); 1 is a clear slightly colored appearance (APHA < 100); 2 is clear, slightly amber (APHA < 500); 3 is a dark amber color that is almost opaque (APHA > 500); 4 is opaque dark black (APHA > 500). The specific test results are shown in table 1 below.
TABLE 1 stability test results
The detection result shows that:
the stable choline solution prepared by the method provided by the invention in the examples 1-5 slightly discolors after 7 days and keeps unchanged within 30-60 days, and the choline solution is proved to be stable in property and long in duration. The sample in example 6 slightly changed color after 7 days, and became clear and slightly amber in color after 30 to 60 days. Compared with comparative examples 1-2 without the addition of the stabilizer, Hofmann elimination is effectively inhibited.
Comparative examples 1 to 2, to which no stabilizer was added, started to turn a dark amber color which was almost opaque on day 2 and turned a dark black color which was transparent on day 4, and it was confirmed that the choline hydroxide solution to which the stabilizer was added was unstable and easily subjected to hofmann elimination, and decomposed into many by-products such as olefine aldehyde polymers, and the color became dark.
The pure choline hydroxide solution with the concentration of 60 percent and added with 1000ppm of sodium hydrosulfite slightly changes color after 7 days and keeps unchanged within 30 to 60 days, and the effect of stability is the same as that of the invention to a certain extent.
Comparative example 4 a 60% pure choline hydroxide solution with a concentration of 1000ppm sodium sulfite added and comparative example 5 a 60% pure choline hydroxide solution with a concentration of 1000ppm benzaldehyde added changed slightly after 1 day, became clear slightly amber after 7 days and became almost opaque dark amber after 30 days.
In conclusion, the stable choline solution and the preparation method thereof take choline carbonate as a stabilizer, obviously eliminate side reactions, have long stable retention time, do not introduce other substances, and have stable and safe process.
It should be noted that the above-mentioned preferred embodiments are merely illustrative of the technical concepts and features of the present invention, and are intended to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and not to limit the scope of the present invention. All equivalent changes and modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.
Claims (8)
1. A stabilized choline solution characterized by: comprising choline hydroxide, water, and choline carbonate;
the concentration of choline carbonate in the choline solution is 15-20%;
the preparation method comprises the following steps:
1) adding trimethylamine into water, stirring and mixing, introducing carbon dioxide, stirring while adding, wherein the pressure is less than 2kgf/cm2Obtaining a solution containing trimethylamine and trimethyl ammonium carbonate at the temperature of 10-40 ℃;
2) adding ethylene oxide, trimethylamine, ethylene oxide and water into the solution prepared in the step to react to generate choline hydroxide; trimethyl ammonium carbonate, ethylene oxide and water react to generate choline carbonate; and cooling and filtering to obtain the stable choline solution.
2. A stabilized choline solution according to claim 1 wherein: the molar ratio of trimethylamine to carbon dioxide in the step 1) is trimethylamine to carbon dioxide = 8.5-10: 1.
3. A stabilized choline solution according to claim 1 wherein: the preparation method comprises the step 1) of preparing the trimethylamine, wherein the trimethylamine is trimethylamine aqueous solution with the concentration of 40-50% or liquefied trimethylamine with the purity of 99%.
4. A stabilized choline solution according to claim 1 wherein: the preparation method comprises the following steps that the molar ratio of the ethylene oxide in the step 2) to the trimethylamine in the step 1) is ethylene oxide to trimethylamine =1: 1.
5. A stabilized choline solution according to claim 1 wherein: the temperature is reduced to 30-60 ℃ in the step 2).
6. A stabilized choline solution according to claim 1 wherein: the temperature reduction in the step 2) of the preparation method is cooling water temperature reduction or ice water circulating cooling temperature reduction.
7. A stabilized choline solution according to claim 1 wherein: in the preparation method, in the step 2), ethylene oxide is added when the temperature is 30-60 ℃.
8. A stabilized choline solution according to claim 1 wherein: the preparation method comprises the step 2) of liquefying the ethylene oxide with the concentration of 99%.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1999051796A1 (en) * | 1998-04-06 | 1999-10-14 | Olin Microelectronic Chemicals, Inc. | Method for removing photoresist and plasma etch residues |
| CN1984875A (en) * | 2004-07-09 | 2007-06-20 | 阿克佐诺贝尔股份有限公司 | Composition comprising choline hydroxide and process for preparing the same |
| CN103874679A (en) * | 2012-04-13 | 2014-06-18 | 亨斯迈石油化学有限责任公司 | Using novel amines to stabilize quaternary trialkylalkanolamines |
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1999051796A1 (en) * | 1998-04-06 | 1999-10-14 | Olin Microelectronic Chemicals, Inc. | Method for removing photoresist and plasma etch residues |
| CN1984875A (en) * | 2004-07-09 | 2007-06-20 | 阿克佐诺贝尔股份有限公司 | Composition comprising choline hydroxide and process for preparing the same |
| CN103874679A (en) * | 2012-04-13 | 2014-06-18 | 亨斯迈石油化学有限责任公司 | Using novel amines to stabilize quaternary trialkylalkanolamines |
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