Narrow-distribution fatty alcohol-polyoxyethylene ether as well as preparation method and application thereof

Abstract

The invention discloses narrow-distribution fatty alcohol-polyoxyethylene ether and a preparation method and application thereof.The preparation method mainly comprises the following steps that 1, fatty alcohol with different carbon chain lengths serves as an initiator and is subjected to an addition reaction with ethylene oxide under the action of a basic catalyst, and then an intermediate is prepared through the processes of acid neutralization, adsorption separation and the like; and (2) reacting the intermediate prepared in the step (1) with ethylene oxide under the action of a composite catalyst by taking the intermediate prepared in the step (1) as an initiator to prepare the narrow-distribution fatty alcohol-polyoxyethylene ether. The preparation method provided by the invention has the advantages of high reaction speed, high product yield and the like, the production cost of industrial products can be effectively reduced, the prepared narrow-distribution fatty alcohol-polyoxyethylene ether is narrow in relative molecular mass distribution, low in residual alcohol content and free of high-EO polyether components, and compared with a traditional fatty alcohol polyether product catalyzed by a single base, the narrow-distribution fatty alcohol-polyoxyethylene ether has the advantages that the reaction speed is high, and the product yield is high. The pour point is lower, and the wettability on fabrics and hard surfaces is obviously superior.

Description

Technical Field

[0001] The invention belongs to the field of polyether synthesis, and specifically relates to a narrow distribution fatty alcohol polyoxyethylene ether and a preparation method and application thereof. Background Art

[0002] Fatty alcohol polyoxyethylene ether is a surfactant with excellent comprehensive performance. It is made of different types of fatty alcohols as raw materials and polymerized with ethylene oxide under the action of catalysts. Among them, the hydrocarbon chain is a hydrophobic group, and the hydroxyl group is a hydrophilic group, which makes fatty alcohol polyoxyethylene ether have good amphiphilic properties and good biodegradability, making it widely used in various fields such as daily chemicals, textiles and industrial cleaning.

[0003] The synthesis process of fatty alcohol polyoxyethylene ether is mainly based on alkaline catalytic systems such as potassium hydroxide and sodium methoxide. When preparing products by this method, the catalyst dosage is high, the reaction time is long, and the content of metal ions in the product is also relatively high. The relative molecular mass distribution of the product is relatively wide, and there will be a large proportion of high EO polyether components and low molecular weight residual alcohols, which reduces the comprehensive performance of the product such as wetting speed, emulsification and oil removal.

[0004] Patent CN101260027A discloses a method for preparing narrow distribution fatty alcohol polyoxyethylene ether, which separates light and heavy components in the raw alcohol ether by molecular distillation. Although narrow distribution fatty alcohol polyoxyethylene ether can also be obtained, the cumbersome process undoubtedly increases a large amount of energy consumption, and the separation of some polyether components also reduces the overall product yield. Patent CN106750247A discloses a method for preparing low free alcohol fatty alcohol polyoxyethylene ether, which adopts a two-step synthesis process, firstly, fatty alcohol and ethylene carbonate are reacted to generate hydroxyethyl alkyl ether, and then catalyzed under alkaline conditions to react with EO to synthesize fatty alcohol polyoxyethylene ether. The catalyst dosage under this process is relatively high, although the proportion of free alcohol in the product can be reduced to a certain extent, it will inevitably lead to the formation of high EO polyether components, reducing the overall performance of the product. Summary of the invention

[0005] The object of the present invention is to provide a narrow distribution fatty alcohol polyoxyethylene ether, which has a narrow relative molecular weight distribution, a low residual alcohol content, does not contain a high EO polyether component, and has the properties of good wetting and permeability.

[0006] Another object of the present invention is to provide a method for preparing the above narrow distribution fatty alcohol polyoxyethylene ether, and the application of fatty alcohol polyoxyethylene ether in the fields of leather degreasing and hard surface cleaning.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] On the one hand, the present invention provides a method for preparing narrow distribution fatty alcohol polyoxyethylene ether, which specifically comprises the following steps:

[0009] (1) placing a fatty alcohol and a basic catalyst in a reactor, replacing with nitrogen, vacuuming and dehydrating, and heating to introduce a portion of ethylene oxide until the pressure in the reactor no longer decreases;

[0010] (2) cooling and adding acid for neutralization, followed by adsorption separation to obtain an intermediate;

[0011] (3) placing the intermediate and composite catalyst prepared above in a reaction vessel, replacing the atmosphere with nitrogen, vacuuming and dehydrating, stirring and heating, and introducing another portion of ethylene oxide until the pressure in the reactor no longer decreases, thereby obtaining a narrow distribution fatty alcohol polyoxyethylene ether.

[0012] Furthermore, the fatty alcohol in step (1) is at least one of fatty alcohols having a chain of 8 to 22 carbon atoms, preferably at least one of straight-chain fatty alcohols having 8 to 22 carbon atoms, more preferably C 8-10 Straight chain fatty alcohol, C 12-14 Straight chain fatty alcohol, C 16-18 At least one of the following linear fatty alcohols.

[0013] Furthermore, the alkaline catalyst in step (1) is one or more of sodium hydroxide, potassium hydroxide, calcium hydroxide, and sodium methoxide. Preferably, the amount of the alkaline catalyst used is 0.001 to 0.5 wt % of the total mass of the fatty alcohol and the ethylene oxide introduced in step (1), and more preferably 0.03 to 0.3 wt %.

[0014] Furthermore, the step (1) is heating to a reaction temperature of 130 to 180°C;

[0015] Preferably, the amount of ethylene oxide used in step (1) accounts for 5 to 50 wt %, preferably 15 to 40 wt %, of the total amount of ethylene oxide.

[0016] Preferably, in step (1), the molar ratio of fatty alcohol to ethylene oxide is 1:0.5-10, preferably 1:2-8.

[0017] In a specific embodiment, the ethylene oxide in step (1) can be added multiple times or all at once; the reaction temperature can be raised to a specified temperature all at once or multiple times in coordination with the addition of ethylene oxide.

[0018] In a preferred embodiment, in step (1), ethylene oxide is added in at least two portions, and the reaction temperature is raised at least twice in coordination with the addition of ethylene oxide.

[0019] Furthermore, the dehydration temperature in step (1) and step (3) is 70-80° C., and the dehydration time is 1-1.5 h, until the moisture content is less than 1 wt %.

[0020] Furthermore, in step (2), the temperature is lowered to 60-100° C. and an acid is added for neutralization. Preferably, the acid is at least one of hydrochloric acid, acetic acid, and phosphoric acid. The molar ratio of the amount of the acid added to the amount of the alkaline catalyst used in step (1) is 1-1.05:1, preferably 1-1.03:1.

[0021] Furthermore, the specific steps of the adsorption separation in step (2) are: adding an adsorbent to the acid-neutralized solution for adsorption, and filtering to obtain an intermediate.

[0022] Preferably, the adsorbent is at least one of diatomaceous earth, magnesium silicate and alumina. Preferably, the adsorbent particle size is 0.1-0.5 μm. Preferably, the amount of the adsorbent is 0.05-5wt% of the amount of the intermediate, preferably 0.08-2wt%.

[0023] Preferably, the temperature of the adsorption process is 60-130° C., preferably 80-120° C. Preferably, stirring can be performed during adsorption at a speed of 600-1200 rpm.

[0024] The purpose of the adsorption separation in step (2) of the present invention is to remove sodium, potassium, calcium ions, etc., so as to avoid the problem that the composite catalyst in step (3) is difficult to activate in the presence of sodium and potassium ions and cannot catalyze the reaction of the intermediate / fatty alcohol with ethylene oxide.

[0025] Furthermore, the composite catalyst in step (3) is a mixture of a double metal cyanide catalyst and a phosphazene catalyst in a certain proportion. Preferably, the mass ratio of the double metal cyanide catalyst to the phosphazene catalyst is 0.01 to 35:1, preferably 0.03 to 15:1.

[0026] Specifically, the double metal cyanide catalyst is one or more of a zinc aluminum cyanide catalyst, a zinc cobalt cyanide catalyst, an aluminum chromium cyanide catalyst, a manganese aluminum cyanide catalyst, and a cobalt chromium cyanide catalyst; a commercially available double metal cyanide catalyst can be used, or it can be homemade with reference to patents such as US5470813A and CN114213645A.

[0027] Specifically, the phosphazene catalyst is one or more of phosphazene oxide and phosphazene salt.

[0028] Preferably, the amount of the composite catalyst used is 0.0005-0.03 wt % of the total mass of the intermediate in step (3) and ethylene oxide, more preferably 0.001-0.015 wt %.

[0029] Furthermore, in step (3), the stirring is heated to a reaction temperature of 110 to 170°C.

[0030] Furthermore, in step (3), the molar ratio of the intermediate to ethylene oxide is 1:2-30, preferably 1:3-20.

[0031] In a specific embodiment, the ethylene oxide in step (3) can be added multiple times or all at once; the reaction temperature can be raised to a specified temperature all at once or it can be raised multiple times in conjunction with the addition of ethylene oxide.

[0032] In a preferred embodiment, in step (3), ethylene oxide is added in at least two portions, and the reaction temperature is raised at least twice in coordination with the addition of ethylene oxide.

[0033] On the other hand, the present invention provides a narrow distribution fatty alcohol polyoxyethylene ether prepared by the above preparation method, which has a narrow relative molecular weight distribution (PDI is 1.02-1.03), a low free alcohol content (≤0.65wt%), does not contain a high EO polyether component (<0.01wt%), and has good wetting and permeability.

[0034] On the other hand, the present invention also provides the application of the narrow distribution fatty alcohol polyoxyethylene ether in the fields of leather degreasing and hard surface cleaning.

[0035] Compared with the prior art, the beneficial effects of the present invention are:

[0036] (1) The present invention provides a method for preparing a narrow distribution fatty alcohol polyoxyethylene ether, which adopts a two-step synthesis process. First, a fatty alcohol is used as an initiator, and it is subjected to an addition polymerization reaction with ethylene oxide (EO) under an alkaline catalyst system to generate a low molecular weight polyether intermediate, thereby avoiding the problem that a high EO polyether component is easily generated by direct catalysis of a composite catalyst. Then, starting from the intermediate, a narrow distribution fatty alcohol polyoxyethylene ether is prepared under the action of a composite catalyst system. The product yield under this process is higher.

[0037] (2) The preparation process of the method of the present invention is simple, the reaction conditions are mild and controllable, the catalyst activity is high, the dosage is small, the reaction speed is fast, and the production cost is greatly reduced.

[0038] (3) Compared with the traditional single base catalytic system, the fatty alcohol polyoxyethylene ether prepared by the present invention has a higher effective substance content, a narrow relative molecular weight distribution, a low surface tension, and a higher surface activity. It has significantly improved wetting properties on fabrics and hard surfaces, which is conducive to expanding the application of fatty alcohol polyoxyethylene ether in the fields of leather degreasing and hard surface cleaning. DETAILED DESCRIPTION

[0039] The present invention is further described below by means of specific examples. The examples described in the present invention are only used to illustrate the present invention and do not limit the scope of the present invention.

[0040] The double metal cyanide catalyst used in the present invention is purchased from Huaian Bader Polyurethane Technology Co., Ltd.

[0041] Test method:

[0042] The determination methods of molecular weight distribution index PDI, free alcohol content and high EO polyether content are all in accordance with GB / T 27843-2011.

[0043] The wetting performance is determined according to GB / T 11983-2008. The shorter the wetting time, the better the wetting performance.

[0044] Example 1 (AEO12 / 141.5+5.5) Preparation of C12-14 linear fatty alcohol polyoxyethylene ether, the ratio of EO numbers in the base catalysis stage to the composite catalysis stage is 1.5:5.5

[0045] (1) 745 g of C12-14 straight-chain fatty alcohol and 1 g of potassium hydroxide were added to a self-priming stirring reactor. After the reactor was sealed, nitrogen was replaced three times, and then dehydrated at 80° C. under negative pressure for 1 h. Then, 25 g of ethylene oxide was introduced after the temperature was raised to 140° C., and then 230 g of ethylene oxide was introduced after the temperature was further raised to 155° C. until the pressure in the reactor no longer decreased. After cooling to 90° C., 1.09 g of acetic acid was added for neutralization. Part of nitrogen was filled into the reactor to a slight positive pressure, and the material was discharged after cooling to below 70° C. 800 g of the obtained fatty alcohol polyoxyethylene ether intermediate and 4.0 g of diatomaceous earth with a particle size of 0.2 μm were added to a three-necked flask for adsorption. The stirring speed was 800 rpm and the temperature was 85° C., and the purified fatty alcohol polyoxyethylene ether intermediate was obtained by positive pressure filtration.

[0046] (2) 517 g of the refined fatty alcohol polyoxyethylene ether intermediate prepared above and 0.12 g of the composite catalyst were added to a self-priming stirred reactor, wherein the mass ratio of Zn3[Al(CN)6]2·(ZnCl2)·3-n-butanol·2-propylene glycol to hexaphenoxycyclotriphosphazene was 0.03:1. The reactor was sealed and replaced with nitrogen three times, then dehydrated at 75°C under negative pressure for 1 h, then heated to 115°C and introduced with 50 g of ethylene oxide, and then continued to heat to 125°C and introduced with 433 g of ethylene oxide until the pressure in the reactor no longer decreased. The reactor was cooled to below 70°C and then discharged.

[0047] Example 2 (AEO8 / 10 2+7) Preparation of C8-10 straight chain fatty alcohol polyoxyethylene ether, the ratio of EO number in the base catalysis stage to the composite catalysis stage is 2:7

[0048] (1) 621 g of C8-10 straight-chain fatty alcohol and 0.3 g of sodium hydroxide were added to a self-priming stirring reactor. The reactor was sealed and replaced with nitrogen three times, then dehydrated at 80° C. under negative pressure for 1.5 h, then heated to 150° C. and introduced 38 g of ethylene oxide, and then continued to heat to 160° C. and introduced 341 g of ethylene oxide until the pressure in the reactor no longer decreased. After cooling to 80° C., 0.93 g of 30 wt % hydrochloric acid solution was added, and part of nitrogen was filled into the reactor to a slight positive pressure. After cooling to below 70° C., the material was discharged. 900 g of the obtained fatty alcohol polyoxyethylene ether intermediate and 0.72 g of magnesium silicate with a particle size of 0.5 μm were added to a three-necked flask for adsorption, the stirring speed was 1000 rpm, the temperature was 95° C., and the purified fatty alcohol polyoxyethylene ether intermediate was obtained by positive pressure filtration.

[0049] (2) In a self-priming stirred reactor, 430 g of the purified fatty alcohol polyoxyethylene ether intermediate prepared above and 0.05 g of a composite catalyst were added, wherein Co3[Cr(CN)6]2·(CoCl2)·3-tert-butyl alcohol·2-propylene glycol and [(C6H 11 )CH3N]4P + BF4 - The ratio is 12.5:1. After the reactor is sealed, nitrogen is replaced three times, and then dehydration is carried out at 80°C under negative pressure for 1h. Then, the temperature is raised to 145°C and 57g of ethylene oxide is introduced. Then, the temperature is continued to be raised to 150°C and 513g of ethylene oxide is introduced until the pressure in the reactor no longer decreases. The material is discharged after cooling to below 70°C.

[0050] Example 3 (AEO16 / 18 3+9) Preparation of C16-18 straight chain fatty alcohol polyoxyethylene ether, the ratio of the base catalysis stage to the composite catalysis stage is 3:9

[0051] (1) Add 660g of C16-18 fatty alcohol and 0.6g of sodium methoxide to a self-priming stirred reactor. After the reactor is sealed, nitrogen is replaced three times, and then dehydrated and methanol are added at 80°C under negative pressure for 1.2h. Then, 34g of ethylene oxide is introduced after the temperature is raised to 135°C, and then 306g of ethylene oxide is introduced after the temperature is further raised to 145°C until the pressure in the reactor no longer decreases. After cooling to 80°C, 0.68g of acetic acid is added for neutralization. Part of nitrogen is filled into the reactor to a slight positive pressure, and the material is discharged after cooling to below 70°C. 900g of the obtained fatty alcohol polyoxyethylene ether intermediate and 45g of magnesium silicate with a particle size of 0.1μm are added to a three-necked flask for adsorption. The stirring speed is 1200rpm and the temperature is 100°C. The purified fatty alcohol polyoxyethylene ether intermediate is obtained by positive pressure filtration.

[0052] (2) 495 g of the refined fatty alcohol polyoxyethylene ether intermediate prepared above and 0.1 g of the composite catalyst were added to a self-priming stirred reactor, wherein the ratio of Mn3[Al(CN)6]2·(MnCl2)·3-n-butanol·2-propylene glycol to hexaphenoxycyclotriphosphazene was 3.6:1. The reactor was sealed and replaced with nitrogen three times, then dehydrated at 76°C under negative pressure for 1 h, then heated to 150°C and introduced with 50 g of ethylene oxide, and then continued to heat to 170°C and introduced with 455 g of ethylene oxide until the pressure in the reactor no longer decreased. The reactor was cooled to below 70°C and then discharged.

[0053] Comparative Example 1 (AEO12 / 14+7) Preparation of C12-14 straight chain fatty alcohol polyoxyethylene ether, catalytically connected with 7 EO

[0054] Add 385g of C12-14 fatty alcohol and 1.5g of potassium hydroxide to a self-priming stirred reactor. After the reactor is sealed, replace with nitrogen three times, then dehydrate at 80°C under negative pressure for 1h, then heat to 140°C and introduce 31g of ethylene oxide, then continue to heat to 155°C and introduce 584g of ethylene oxide, age until the pressure in the reactor no longer decreases, cool to below 70°C and then discharge.

[0055] Comparative Example 2 (AEO8 / 10+9)

[0056] In a self-priming stirred reactor, 267 g of C8-10 fatty alcohol and 0.05 g of Mn3[Al(CN)6]2·(MnCl2)·3-n-butanol·2-propylene glycol were added. The reactor was sealed and replaced with nitrogen three times, then dehydrated at 80°C under negative pressure for 1 h, and then the temperature was raised to 150°C and 37 g of ethylene oxide was introduced. The temperature was then continued to rise to 160°C and 696 g of ethylene oxide was introduced until the pressure in the reactor no longer decreased. The reactor was cooled to below 70°C and then discharged.

[0057] Comparative Example 3 (AEO16 / 18 3+9) Preparation of C16-18 linear fatty alcohol polyoxyethylene ether, the ratio of EO numbers in the base catalysis stage to the phosphazene catalysis stage is 3:9

[0058] (1) Add 660g of C16-18 fatty alcohol and 0.6g of sodium methoxide to a self-priming stirred reactor. After the reactor is sealed, nitrogen is replaced three times, and then dehydrated and methanol are added at 80°C under negative pressure for 1.2h. Then, 34g of ethylene oxide is introduced after the temperature is raised to 135°C, and then 306g of ethylene oxide is introduced after the temperature is further raised to 145°C until the pressure in the reactor no longer decreases. After cooling to 80°C, 1.13g of acetic acid is added for neutralization. Part of nitrogen is filled into the reactor to a slight positive pressure, and the material is discharged after cooling to below 70°C. 900g of the obtained fatty alcohol polyoxyethylene ether intermediate and 45g of magnesium silicate with a particle size of 0.1μm are added to a three-necked flask for adsorption. The stirring speed is 1200rpm and the temperature is 100°C. The purified fatty alcohol polyoxyethylene ether intermediate is obtained by positive pressure filtration.

[0059] (2) Add 495 g of the refined fatty alcohol polyoxyethylene ether intermediate prepared above and 0.1 g of hexaphenoxy cyclotriphosphazene into a self-priming stirred reactor. After the reactor is sealed, replace with nitrogen three times, then dehydrate at 76° C. under negative pressure for 1 h, then heat to 150° C. and introduce 50 g of ethylene oxide, then continue to heat to 170° C. and introduce 455 g of ethylene oxide until the pressure in the reactor no longer decreases, cool to below 70° C. and then discharge.

[0060] The molecular weight distribution index, free alcohol content, high EO polyether content, wetting properties, etc. of the linear fatty alcohol polyoxyethylene ethers prepared in each embodiment and comparative example were tested, and the test results are shown in the following table.

[0061] Among them, high EO polyether is an abnormally high molecular weight component with an EO number greater than 40 generated during the reaction.

[0062]

[0063] Unless otherwise defined, the terms used in the present invention have the meanings commonly understood by those skilled in the art.

[0064] The embodiments described in the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention. Those skilled in the art may make various other substitutions, changes and improvements within the scope of the present invention. Therefore, the present invention is not limited to the above embodiments, but is only limited by the claims.

Claims

1. A method for preparing narrow distribution fatty alcohol polyoxyethylene ether, characterized in that: The following steps are involved: (1) placing a fatty alcohol and a basic catalyst in a reactor, replacing with an inert gas, dehydrating, and introducing ethylene oxide at a high temperature until the pressure in the reactor no longer decreases; (2) adding acid for neutralization, followed by adsorption separation to obtain an intermediate; (3) placing the intermediate and composite catalyst prepared above in a reactor, replacing with inert gas, dehydrating, heating, and introducing ethylene oxide until the pressure in the reactor no longer decreases, thereby obtaining a narrow distribution fatty alcohol polyoxyethylene ether.

2. The preparation method according to claim 1, characterized in that: The fatty alcohol is at least one of fatty alcohols with a chain of 8 to 22 carbon atoms; preferably at least one of fatty alcohols with a straight chain of 8 to 22 carbon atoms; more preferably at least one of C8-10 straight chain fatty alcohols, C12-14 straight chain fatty alcohols, and C16-18 straight chain fatty alcohols.

3. The preparation method according to claim 1, characterized in that: The alkaline catalyst is one or more of sodium hydroxide, potassium hydroxide, calcium hydroxide, and sodium methoxide, and the composite catalyst is a mixture of a double metal cyanide catalyst and a phosphazene catalyst in a certain proportion; Preferably, the mass ratio of the double metal cyanide catalyst to the phosphazene catalyst is 0.01 to 35:1, preferably 0.03 to 15:1; Preferably, the double metal cyanide catalyst is one or more of a zinc aluminum cyanide catalyst, a zinc cobalt cyanide catalyst, an aluminum chromium cyanide catalyst, a manganese aluminum cyanide catalyst, and a cobalt chromium cyanide catalyst; and the phosphazene catalyst is one or more of an oxide phosphazene and a phosphazene salt.

4. The preparation method according to claim 1, characterized in that: The amount of the alkaline catalyst used is 0.001 to 0.5 wt % of the mass of the fatty alcohol and the ethylene oxide introduced in step (1), preferably 0.03 to 0.3 wt %; the amount of the composite catalyst used is 0.0005 to 0.03 wt % of the mass of the intermediate and the ethylene oxide introduced in step (3), more preferably 0.001 to 0.015 wt %.

5. The preparation method according to claim 1, characterized in that: The dehydration temperature in step (1) and step (3) is 70-80°C, and the dehydration time is 1-1.5h, until the water content is less than 1wt%; preferably, the reaction temperature in step (1) is 130-180°C, and the reaction temperature in step (3) is 110-170°C; preferably, the amount of ethylene oxide used in step (1) accounts for 5-50wt% of the total amount of ethylene oxide, preferably 15-40wt%.

6. The preparation method according to claim 1, characterized in that: The acid in step (2) is at least one of hydrochloric acid, acetic acid and phosphoric acid, and the preferred neutralization temperature is 60-100°C.

7. The preparation method according to claim 1, characterized in that: The specific steps of adsorption separation are: adding an adsorbent to the acid-neutralized solution for adsorption, and filtering to obtain an intermediate.

8. The preparation method according to claim 7, characterized in that: The adsorbent is at least one of diatomaceous earth, magnesium silicate and alumina; preferably, the amount of the adsorbent is 0.05-5wt% of the intermediate; preferably, the adsorbent particle size is 0.1-0.5 μm; preferably, the temperature of the adsorption process is 60-130°C, preferably 80-120°C.

9. The narrow distribution fatty alcohol polyoxyethylene ether prepared by the preparation method according to any one of claims 1 to 8, wherein the molecular weight distribution index PDI ≤ 1.03, the free alcohol content ≤ 0.65 wt%, and the high EO polyether content < 0.01 wt%.

10. Application of the narrow distribution fatty alcohol polyoxyethylene ether prepared according to the preparation method according to any one of claims 1 to 8 in the fields of leather degreasing and hard surface cleaning.

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