Cardanol polyoxyethylene ether sodium sulfate and preparation method thereof
By combining a falling film sulfonation reactor with air-diluted SO3 gas, the preparation process of cashew phenol polyoxyethylene ether sulfate sodium salt was controlled, solving the problems of severe side reactions and low sulfonation degree, and achieving high-quality and efficient continuous production.
Patent Information
- Application Number
- CN202511272381.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-08
- Publication Date
- 2025-11-21
AI Technical Summary
Existing technologies result in severe side reactions, low sulfonation, and difficulty in controlling the reaction due to high temperatures during the preparation of cashew phenol polyoxyethylene ether sulfate salts. This leads to a darker product color, breakage of epoxy bonds, and negatively impacts product quality.
A method combining a falling film sulfonation reactor with air-diluted SO3 gas was adopted to control the reaction temperature and residence time. NaOH was used as a neutralizing agent, and the sodium salt of cashew phenol polyoxyethylene ether sulfate was prepared through sulfonation, neutralization and vacuum degassing processes.
Reduce side reactions, increase sulfonation degree, lower reaction temperature, ensure product quality, achieve continuous production, and improve safety and production efficiency.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of fine chemical technology, and in particular to a sodium salt of cashew phenol polyoxyethylene ether sulfate and its preparation method. Background Technology
[0002] Alkylphenol polyoxyethylene ether sulfate salts possess advantages such as strong penetrability, high detergency, good foaming and foam stability, strong solubility for inorganic salts, and low irritation to human skin. They are widely used in personal care products, the petroleum and textile industries, pesticide production, and industrial cleaning. However, because the synthesis of petroleum-based alkylphenols causes environmental pollution, and the raw materials are highly susceptible to fluctuations in global oil prices, there is an urgent need to find a natural organic phenol to replace petroleum-based alkylphenols.
[0003] Cashew nut shell extract, obtained by pressing cashew nut shells, is a natural and renewable raw material obtained through vacuum distillation. It is inexpensive and widely available. Cashew nut shell polyoxyethylene ethers, made from natural cashew nut shells, replace petroleum-based alkylphenol polyoxyethylene ethers, avoiding the adverse environmental impacts of petroleum-based synthesis processes. Furthermore, the raw material is inexpensive and renewable, and the product is biodegradable. Therefore, polyoxyethylene ether sulfates synthesized using natural phenols instead of petroleum phenols have natural advantages in terms of both environment and price. Currently reported cashew nut shell polyoxyethylene ether sulfate salts mainly include ammonium and calcium salts, both of which use aminosulfonic acid as the sulfonating agent.
[0004] Chinese patent CN101941926A discloses a cashew phenol polyoxyethylene ether sulfate ammonium salt and its preparation method. The method involves reacting cashew phenol polyoxyethylene ether, sulfamic acid, and a catalyst at 110-150℃, followed by neutralization with sodium hydroxide, cooling, and filtration to obtain the product. During the sulfamic acid reaction, side reactions inevitably occur, including hydrolysis, oxidation, and polysulfonation. Reducing agents or reaction control are needed to suppress these side reactions. Furthermore, the sulfamic acid reaction requires a relatively high temperature; high temperatures make reaction control difficult, increase material viscosity, hinder heat transfer, and further exacerbate side reactions, resulting in a darker product color and lower sulfonation degree. High temperatures also cause the epoxy bonds in the polyoxyethylene ether to break, leading to an increase in dioxane content in the product and affecting its usability. Summary of the Invention
[0005] To address the problems existing in the prior art, the present invention aims to provide a method for preparing sodium cashew phenol polyoxyethylene ether sulfate with low degree of side reaction and high degree of sulfonation; another objective of the present invention is to provide sodium cashew phenol polyoxyethylene ether sulfate.
[0006] This invention discloses a method for preparing sodium salt of cashew phenol polyoxyethylene ether sulfate, comprising the following steps:
[0007] S1: Cashew phenol polyoxyethylene ether and SO3 gas are reacted at 50-100℃ to generate cashew phenol polyoxyethylene sulfate.
[0008] S2: Mix the generated cashew phenol polyoxyethylene sulfate with an alkaline solution and neutralize to obtain cashew phenol polyoxyethylene ether sulfate sodium salt.
[0009] Furthermore, in step S1, the cashew phenol polyoxyethylene ether has a solid content >99%, moisture content <0.1wt%, iodine value 75-79 g / 100g, and dry air dew point <-60℃. Its structural formula is:
[0010] Where n is 0, 2, 4 or 6, m is 2-25, and the cashew phenol polyoxyethylene ether is an addition product obtained by ethoxylation reaction of cashew phenol and ethylene oxide.
[0011] The chemical reaction equations for steps S1 and S2 are as follows:
[0012] .
[0013] Furthermore, in step S1, cashew phenol polyoxyethylene ether and SO3 gas undergo a contact reaction in a falling film sulfonation reactor.
[0014] Falling film sulfonation reactors are used in chemical production for gas-liquid phase reactions, especially sulfonation reactions. Their main advantages include:
[0015] High-efficiency mass transfer: Falling film reactors greatly increase the gas-liquid contact area and improve mass transfer efficiency by forming a thin film of liquid along the tube wall.
[0016] Excellent temperature control: Because the liquid flows in the form of a thin film, heat can be dissipated quickly and evenly, which helps to maintain a stable reaction temperature, especially important for sulfonation reactions that require precise temperature control.
[0017] Controllable residence time: The residence time of materials in the reactor can be controlled by adjusting the flow rate, thereby optimizing reaction conditions and improving product selectivity.
[0018] Reduce byproduct formation: Stable temperature and good mixing help reduce unnecessary side reactions and improve the purity of the target product.
[0019] Furthermore, the SO3 gas is SO3 gas diluted with dry air, and the concentration of the diluted SO3 gas is 4.0-7.0 v / v.
[0020] Using air to dilute SO3 before it enters the falling film sulfonation reactor offers several advantages:
[0021] Enhanced safety: Air dilution of SO3 reduces the concentration of reactant gases, thus reducing the risk of explosion or combustion.
[0022] Mild reaction: Dilution with air can make the reaction milder and more stable, which helps to better control the reaction rate and prevent the increase of side reactions caused by local overheating.
[0023] Improved product quality: Milder reaction conditions help to obtain higher quality products because the reaction process can be better controlled, reducing the occurrence of over-sulfonation or other side reactions.
[0024] Enhanced operational flexibility: Using air dilution allows for flexible adjustment of the proportion of reaction gases according to specific process requirements, facilitating the adjustment of production process parameters based on different raw materials and product specifications.
[0025] In summary, the application of falling film sulfonation reactors combined with air dilution technology can not only improve production efficiency and product quality, but also significantly enhance operational safety and flexibility.
[0026] Furthermore, in step S1, the molar ratio of cashew phenol polyoxyethylene ether to SO3 is 1:1.2-1.4.
[0027] A slight excess of SO3 increases the reactivity of cashew phenol polyoxyethylene ether.
[0028] Furthermore, in step S2, an alkaline solution is added to control the pH value of the product at 10.5 ± 0.5 (1 wt% aqueous solution of active ingredient); the alkaline solution is an aqueous solution of NaOH.
[0029] Furthermore, in step S2, the cashew phenol polyoxyethylene sulfate is also mixed with water.
[0030] Similar to sodium lauryl ether polyoxyethylene ether sulfate (SLES), cashew phenol polyoxyethylene ether sulfate (COPS) exhibits a gel region, meaning that within a certain content range, the material is fluid; beyond this range, the product becomes non-fluid at room temperature, exhibiting a hard gel or even a solid state. The preparation method disclosed in this invention allows for continuous production. However, it requires the addition of water or alcohol to reduce viscosity and prepare the product to a level outside the gel region that allows for fluidity, unlike batch production methods which only consider liquid alkali neutralization and do not consider fluidity. Both water and alcohol can improve the fluidity of cashew phenol polyoxyethylene ether sulfate, but using water is more economical and environmentally friendly.
[0031] Furthermore, water is added to control the sodium solids content of cashew phenol polyoxyethylene ether sulfate to 30-35% or 50-55%.
[0032] The sodium salt of cashew phenol polyoxyethylene ether sulfate has a gel phase when the mass fraction is between 30-70%, and its fluidity is greatly affected by temperature. Controlling the sodium solid content of cashew phenol polyoxyethylene ether sulfate at 30-35% or 50-55% can ensure its fluidity and is conducive to continuous production.
[0033] Furthermore, the sodium salt of cashew phenol polyoxyethylene ether sulfate is heated and then enters a vacuum degasser to remove byproducts. After being devising and dried with an alcohol solvent, the sodium salt of cashew phenol polyoxyethylene ether sulfate is obtained.
[0034] Furthermore, the heating temperature is 50-80℃; the vacuum degree of the vacuum degasser is controlled at -0.06MPa~-0.095MPa to remove dioxane as a by-product; the alcohol solvent is a monohydric alcohol compound containing 1 to 4 carbon atoms, including methanol, ethanol or isobutanol.
[0035] This invention improves the reaction rate and reduces side reactions by selecting appropriate sulfonating agent types and reaction parameters, thereby increasing the reaction conversion rate. Using cashew phenol polyoxyethylene ether and gaseous SO3 as raw materials, and alkali solution as a neutralizing agent, sodium cashew phenol polyoxyethylene ether sulfate is obtained through sulfonation, neutralization, and vacuum degassing.
[0036] The present invention also discloses a sodium salt of cashew phenol polyoxyethylene ether sulfate, which is prepared by the method for preparing sodium salt of cashew phenol polyoxyethylene ether sulfate described above.
[0037] This invention provides a method for preparing sodium salt of cashew phenol polyoxyethylene ether sulfate, which uses cashew phenol polyoxyethylene ether obtained by ethoxylation of natural raw material cashew phenol as raw material, and gaseous SO3 as sulfonating agent, and obtains the product by neutralization with alkaline solution. The reaction process is fast, produces no waste acid, and has a high product conversion rate. Detailed Implementation
[0038] To make the technical solution of the present invention clearer, the present invention will be further described in detail below with reference to specific embodiments.
[0039] Example 1
[0040] The production device is a gas-phase falling film sulfonation reaction. Gas SO3 is generated by heating and evaporating liquid SO3 in an evaporator (heat transfer oil temperature 80℃, evaporated SO3 gas phase temperature 50℃). Then, it is diluted with dry air to obtain diluted SO3 gas. The liquid SO3 feed rate is 135 kg / h, and the concentration of diluted SO3 gas is 5 v / v. Diluted SO3 gas enters the top of the sulfonator and reacts with cashew phenol polyoxyethylene ether (iodine value 76.1 g / 100g, feed rate 925 kg / h) after being evenly distributed by a distributor. The reaction then occurs within a falling film sulfonation tube, from which the gas flows out from the bottom of the sulfonator. The sulfonator is kept at a reaction temperature of 65°C using hot water. A sample is taken to determine the acid-ester neutralization value, which is 62.8 mg NaOH / g. Alkali solution (NaOH aqueous solution) with a NaOH concentration of 32 wt% (feed rate 208 kg / h) and process water (feed rate 720 kg / h) are added to control the product pH at 10.08 and the product solid content at 55.12%. The neutralized and adjusted product is heated to 75°C via a heat exchanger and then degassed in a vacuum degasser (vacuum degree -80~-85 kPa). A certain amount of process water is continuously and slowly added to maintain a constant solid content. After viscosity reduction and drying with ethanol, cashew phenol polyoxyethylene ether sulfate sodium salt is obtained. The detection parameters of the obtained cashew phenol polyoxyethylene ether sulfate sodium salt are shown in Table 1.
[0041] Table 1. Test results of the sodium cashew phenolate polyoxyethylene ether sulfate obtained in Example 1.
[0042] active ingredients pH value Unsulfided Total dioxane sulfates Sulfonation degree / conversion rate 53.76% 10.08 3.25% 58.12% 28mg / kg 0.33% 94.3%
[0043] Wherein, sulfonation degree = active ingredient / (active ingredient + unsulfurized ingredient), 53.76 / (53.76 + 3.25) = 0.943, which is the reacted content / total content.
[0044] Example 2
[0045] The production device is a gas-phase falling film sulfonation reaction. Gas SO3 is generated by heating and evaporating liquid SO3 in an evaporator (heat transfer oil temperature 80℃, vapor temperature of the evaporated SO3 50℃). Then, it is diluted with dry air to obtain diluted SO3 gas. The liquid SO3 feed rate is 135 kg / h, and the concentration of diluted SO3 gas is 5% vt. Diluted SO3 gas enters the top of the sulfonator and reacts with cashew phenol polyoxyethylene ether (iodine value 77.01 g / 100g, feed rate 900 kg / h) after being evenly distributed by a distributor. The reaction then occurs in a falling film sulfonation tube, from which the gas flows out from the bottom of the sulfonator. The sulfonator maintains a reaction temperature of 85°C using hot water and steam. A sample is taken to determine the acid-ester neutralization value, which is 64.1 mg NaOH / g. Alkali solution (NaOH aqueous solution) with a NaOH concentration of 32 wt% (feed rate 207 kg / h) and process water (feed rate 1740 kg / h) are added to control the product pH at 10.00 and the product solid content at 35.46%. The neutralized and adjusted product is heated to 55°C via a heat exchanger and then degassed in a vacuum degasser (vacuum degree -90~-93 kPa). A certain amount of process water is continuously and slowly added to maintain a constant solid content. After isobutanol viscosity reduction and drying, cashew phenol polyoxyethylene ether sulfate sodium salt is obtained. The detection parameters of the obtained cashew phenol polyoxyethylene ether sulfate sodium salt are shown in Table 2.
[0046] Table 2. Test results of the sodium cashew phenolate polyoxyethylene ether sulfate obtained in Example 2.
[0047] active ingredients pH value Unsulfided Total dioxane sulfates Sulfonation degree / conversion rate 34.96% 10.00 1.49% 37.16% 19mg / kg 0.22% 95.91%
[0048] Examples 3-4
[0049] All process parameters in Examples 3 and 4 are the same as in Example 2, but the cashew phenol polyoxyethylene ether used in Example 3 (iodine value 71.02 g / 100g) and the cashew phenol polyoxyethylene ether used in Example 4 (iodine value 82.44 g / 100g) have different detection parameters. The detection parameters of the obtained cashew phenol polyoxyethylene ether sulfate sodium salt are shown in Table 3.
[0050] Table 3. Test results of the sodium cashew phenolate polyoxyethylene ether sulfate obtained in Examples 3 and 4.
[0051] Example active ingredients pH value Unsulfided Total dioxane sulfates Conversion rate Example 3 28.47% 10.12 3.25% 33.16% 32mg / kg 1.42% 89.75% Example 4 36.52% 8.82 1.26% 40.15% 118mg / kg 0.18% 96.75%
[0052] As can be seen from the above four sets of examples, after the sulfonation reaction of gaseous SO3 with cashew phenol polyoxyethylene ether in a falling film sulfonator, the product sodium cashew phenol polyoxyethylene ether sulfate can be successfully prepared after neutralization, mixing, and degassing. The iodine value of the raw material cashew phenol polyoxyethylene ether has a significant impact on the conversion rate of the sulfonation reaction. The lower the iodine value, the more difficult the sulfonation reaction, the lower the conversion rate, and the poorer the product flowability. The higher the iodine value, the simpler the sulfonation reaction and the higher the conversion rate, but the sulfonating agent SO3 has more addition sites, and more dioxane byproducts are formed. Therefore, the iodine value of the raw material needs to be controlled within a certain range.
[0053] Comparative Example 1
[0054] Prepared using the preparation method of patent CN114276281A:
[0055] Add 564g of cashew phenol polyoxyethylene ether, 18g of carbamide, and 13.2g of hypophosphoric acid to a four-necked flask, heat to 90℃, and dehydrate under vacuum for 30 minutes.
[0056] Add 107g of aminosulfonic acid in four portions, with a 10-minute interval between each addition. After the addition is complete, gradually raise the temperature to 115℃ and maintain the temperature for 4 hours.
[0057] Cool down to 70°C, add ethanol, filter to remove insoluble impurities, heat the filtered material to 75°C, vacuum to remove ethanol, and discharge.
[0058] Comparative Examples 2-5
[0059] Comparative Examples 2-5 were prepared using the same method as Comparative Example 1, with the only difference being the parameters listed in Table 3.
[0060] Table 3 Preparation parameters of Comparative Examples 1-5
[0061] name Cashew phenol polyoxyethylene ether Carboamide hypophosphite Aminosulfonic acid reaction temperature reaction time Sulfonation degree Comparative Example 1 564g 18g 39.6g 107g 115℃ 4h 90.5% Comparative Example 2 564g 18g 39.6g 107g 115℃ 3h 90.8% Comparative Example 3 564g 30g 21.2g 112g 120℃ 3h 88.3% Comparative Example 4 564g 24g 26.4g 97g 110℃ 5h 91.2% Comparative Example 5 476g 30g 26.4g 112g 110℃ 5h 91.8%
[0062] The sulfonation reactions used in Comparative Examples 1-5 involved reactions at temperatures of 110-120°C and requiring 3-5 hours, making continuous production impossible, and the highest degree of sulfonation was only 91.2%. In contrast, the method for preparing cashew phenol polyoxyethylene ether sulfate sodium salt provided by this invention uses gaseous SO3 as the sulfonating agent, resulting in a shorter reaction time, enabling continuous production, producing a higher degree of sulfonation in the reaction product, requiring a lower reaction temperature, and having a higher safety factor, thus offering significant production advantages.
[0063] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.
Claims
1. A method for preparing sodium salt of cashew phenol polyoxyethylene ether sulfate, characterized in that, Includes the following steps: S1: Cashew phenol polyoxyethylene ether and SO3 gas are reacted at 50-100℃ to generate cashew phenol polyoxyethylene sulfate. S2: Mix the generated cashew phenol polyoxyethylene sulfate with an alkaline solution and neutralize to obtain cashew phenol polyoxyethylene ether sulfate sodium salt.
2. The method for preparing sodium cashew phenolate polyoxyethylene ether sulfate according to claim 1, characterized in that, In step S1, the cashew phenol polyoxyethylene ether has a solid content >99%, moisture content <0.1wt%, iodine value 75-79 g / 100g, and dry air dew point <-60℃. Its structural formula is: Where n is 0, 2, 4 or 6, m is 2-25, and the cashew phenol polyoxyethylene ether is an addition product obtained by ethoxylation reaction of cashew phenol and ethylene oxide.
3. The method for preparing sodium cashew phenolate polyoxyethylene ether sulfate according to claim 1, characterized in that, In step S1, cashew phenol polyoxyethylene ether and SO3 gas undergo a contact reaction in a falling film sulfonation reactor.
4. The method for preparing sodium cashew phenolate polyoxyethylene ether sulfate according to claim 3, characterized in that, The SO3 gas is SO3 gas diluted with dry air, and the concentration of SO3 gas after dilution is 4.0-7.0 v / v.
5. The method for preparing sodium cashew phenolate polyoxyethylene ether sulfate according to claim 1, characterized in that, In step S1, the molar ratio of cashew phenol polyoxyethylene ether to SO3 is 1:1.2-1.
4.
6. The method for preparing sodium cashew phenolate polyoxyethylene ether sulfate according to claim 1, characterized in that, In step S2, an alkaline solution is added to control the pH value of the product at 10.5 ± 0.5; the alkaline solution is an aqueous solution of NaOH.
7. The method for preparing sodium cashew phenolate polyoxyethylene ether sulfate according to claim 1, characterized in that, In step S2, the cashew phenol polyoxyethylene sulfate is also mixed with water.
8. The method for preparing sodium cashew phenolate polyoxyethylene ether sulfate according to claim 1, characterized in that, Add water to control the sodium solids content of cashew phenol polyoxyethylene ether sulfate to 30-35% or 50-55%.
9. A method for preparing sodium cashew phenolate polyoxyethylene ether sulfate according to claim 1, characterized in that, The sodium salt of cashew phenol polyoxyethylene ether sulfate is heated and then enters a vacuum degasser to remove byproducts. After being devising and dried with an alcohol solvent, the sodium salt of cashew phenol polyoxyethylene ether sulfate is obtained.
10. A sodium salt of cashew phenol polyoxyethylene ether sulfate, characterized in that, It is prepared by the method for preparing sodium cashew phenol polyoxyethylene ether sulfate according to any one of claims 1-9.
Citation Information
Patent Citations
Cardanol polyoxyethylene ether ammonium sulfate and preparation method thereof
CN101941926A