Non-ionic surfactant as well as preparation method and application thereof

Abstract

The invention provides a nonionic surfactant as well as a preparation method and application thereof, the nonionic surfactant has a structure as shown in the following formula: # imgabs0 #, and m is 3-15. The nonionic surfactant provided by the invention is modified dihydroxy-terminated 2-propyl heptanol polyoxyethylene ether, so that the nonionic surfactant has excellent alkali resistance, emulsification performance and metal cleaning performance.

Description

Technical Field

[0001] The invention belongs to the technical field of surfactants, and in particular relates to a nonionic surfactant and a preparation method and application thereof. Background Art

[0002] Surfactants, as a kind of fine chemicals, are known as "industrial MSG" and are widely used in various fields. According to the ionicity, they can be divided into anionic surfactants, nonionic surfactants, cationic surfactants and amphoteric surfactants. Nonionic surfactants are increasingly used in the field of industrial cleaning due to their excellent degreasing, wetting, emulsification and dispersion properties. And their hydrophilic and lipophilic groups determine the application effect of nonionic surfactants in industrial cleaning. Among them, polyoxyethylene ethers starting with 2-propylheptanol are widely used in industrial cleaning.

[0003] Patent US5661121 reports that 2-propyl heptanol polyoxyethylene ether has excellent foam and cleaning performance when used for hard surface cleaning. However, 2-propyl heptanol polyoxyethylene ether still has the problems of insufficient alkali resistance and poor emulsification performance, and the oil removal performance needs to be further improved.

[0004] Therefore, developing a nonionic surfactant with high alkali resistance, excellent emulsification performance and high oil removal performance is a technical problem that needs to be solved urgently. Summary of the invention

[0005] In view of the problems existing in the prior art, the main purpose of the present invention is to provide a non-ionic surfactant having excellent alkali resistance, emulsification and metal cleaning properties.

[0006] The present invention also provides a method for preparing a nonionic surfactant, which can prepare the nonionic surfactant with simple process and low cost.

[0007] In a first aspect, the present invention provides a nonionic surfactant having a structure shown in formula (1):

[0008]

[0009] Among them, the value of m is 3-15, preferably 4-7.

[0010] In the present invention, the hydroxyl value of the nonionic surfactant is 126-321 mgKOH / g.

[0011] In the present invention, the average molecular weight of the nonionic surfactant is 350-890 g / mol.

[0012] The nonionic surfactant represented by the above formula 1 of the present invention has a double-terminal hydroxyl structure, and can be prepared by sequentially adding ethylene oxide and propylene oxide to a system including 2-propylheptanol and a catalyst for reaction.

[0013] In a second aspect, the present invention provides a method for preparing the nonionic surfactant as described above, comprising the following steps:

[0014] 1) mixing 2-propylheptanol, a catalyst and ethylene oxide to carry out a primary reaction;

[0015] 2) Adding propylene oxide to the reaction body of step 1) for secondary reaction to obtain the nonionic surfactant.

[0016] The preparation method as described above, wherein the catalyst is one or more of potassium hydroxide, sodium hydroxide, sodium methoxide, potassium methoxide, and phosphazene catalysts, preferably one or more of potassium hydroxide and phosphazene catalysts;

[0017] The mass of the catalyst is 0.02-1%, preferably 0.1-0.3%, of the total mass of the 2-propylheptanol, ethylene oxide and propylene oxide.

[0018] In the preparation method as described above, the catalyst may also be a Zn / Co bimetallic catalyst;

[0019] The mass of the catalyst is 0.002-0.02% of the total mass of 2-propylheptanol, ethylene oxide and propylene oxide, preferably 0.003-0.006%.

[0020] The preparation method as described above, wherein the molar ratio of 2-propylheptanol to ethylene oxide is 1:3-15, preferably 1:4-7;

[0021] The molar ratio of the 2-propylheptanol to the glycidol is 1:1-1.2, preferably 1:1-1.1.

[0022] In the preparation method as described above, the temperature of the primary reaction in step 1) is 120-190° C., preferably 130-160° C., and the time is 1-8 h, preferably 2-6 h; and the reaction pressure is controlled to be ≤0.6 MPa;

[0023] Step 2) The temperature of the secondary reaction is 110-180° C., preferably 120-150° C., and the time is 0.5-4 h, preferably 1-3 h; the reaction pressure is controlled to be ≤0.4 MPa.

[0024] The preparation method as described above, after the reaction described in step 2) is completed, further includes post-treatment processes such as cooling treatment, neutralization treatment, and degassing treatment, which are conventional operations in the field and are not specifically limited in the present invention.

[0025] The nonionic surfactant provided by the present invention is a terminal hydroxyl polyoxyethylene ether, so that the nonionic surfactant has excellent alkali resistance, emulsification and metal cleaning properties. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] In a first aspect, the present invention provides a nonionic surfactant having a structure shown in Formula 1:

[0028]

[0029] Wherein, the value of m is 3-15.

[0030] The hydroxyl value of the nonionic surfactant provided by the present invention is 126-321 mgKOH / g, for example, 126 mgKOH / g, 140 mgKOH / g, 160 mgKOH / g, 180 mgKOH / g, 200 mgKOH / g, 220 mgKOH / g, 240 mgKOH / g, 260 mgKOH / g, 280 mgKOH / g, 300 mgKOH / g, 321 mgKOH / g, etc.

[0031] The molecular weight of the nonionic surfactant provided by the present invention is 350-890 g / mol, for example, 350 g / mol, 450 g / mol, 550 g / mol, 650 g / mol, 750 g / mol, 850 g / mol, 890 g / mol, etc.

[0032] The nonionic surfactant provided by the present invention has the structure shown in the above formula 1, that is, it has the structure of double-terminal hydroxyl polyoxyethylene ether, and this structural characteristic enables the nonionic surfactant to have excellent alkali resistance, emulsification and metal cleaning performance. The reason is speculated to be that the presence of double-terminal hydroxyl groups enhances the hydrogen bonding of the nonionic surfactant molecules in water, increases solubility, and improves alkali resistance, and its double-terminal hydroxyl polyoxyethylene chain segments make the adsorption of the surfactant at the interface between the water phase and the oil phase more stable, which can better reduce the tension of the liquid / liquid interface and show more excellent emulsification performance; its excellent wetting and emulsification properties enable it to show a relatively excellent oil removal effect in the field of metal cleaning.

[0033] The nonionic surfactant provided by the present invention is a double-terminal hydroxyl polyoxyethylene ether, so that the nonionic surfactant has excellent alkali resistance, emulsification and metal cleaning properties.

[0034] In some embodiments of the present invention, m is 3-15, for example, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, etc.

[0035] In the present invention, as a preferred embodiment, when m is 4-7, the metal cleaning performance of the nonionic surfactant can be further improved.

[0036] In some embodiments of the present invention, the nonionic surfactant is prepared by a method comprising the following process:

[0037] Ethylene oxide and propylene oxide are sequentially added to a system including 2-propylheptanol and a catalyst to carry out a reaction, and the reaction product is subjected to post-treatment including a cooling treatment, a neutralization treatment and a degassing treatment to obtain the nonionic surfactant.

[0038] The raw materials for preparing the nonionic surfactant in the present invention include 2-propylheptanol, a catalyst, ethylene oxide, and glycidol. Specifically, 2-propylheptanol and the catalyst can be mixed, nitrogen replaced, dehydrated and heated (for example, the water content in the reactor is controlled to be below 50 ppm), ethylene oxide is slowly added, and glycidol is slowly introduced after the reaction is completed. After the reaction, the temperature is lowered, neutralized, and degassed to obtain the nonionic surfactant.

[0039] In some embodiments of the present invention, the catalyst is one or more of potassium hydroxide, sodium hydroxide, sodium methoxide, potassium methoxide, and phosphazene catalysts, and the mass of the catalyst is 0.05%-1% of the total mass of 2-propylheptanol, ethylene oxide, and glycidol. Preferably, it is one or more of potassium hydroxide and phosphazene catalysts, and the mass is preferably 0.1%-0.3%.

[0040] In some embodiments of the present invention, the catalyst may also be a Zn / Co bimetallic catalyst, and the mass of the catalyst is 0.002%-0.02% of the total mass of 2-propylheptanol, ethylene oxide, and propylene oxide, preferably 0.003%-0.006%.

[0041] In some embodiments of the present invention, the molar ratio of 2-propylheptanol to ethylene oxide is 1:3-15, such as 1:3, 1:5, 1:7, 1:9, 1:11, 1:13, 1:15, etc., preferably a molar ratio of 1:4-7;

[0042] The molar ratio of the 2-propylheptanol to the glycidol is 1:1-1.2, preferably 1:1-1.1.

[0043] The temperature of the primary reaction is 120-190°C, preferably 130-160°C; the time is 1-8h, preferably 2-6h; the reaction pressure is controlled to be ≤0.6MPa, preferably 0.1-0.6MPa;

[0044] The temperature of the secondary reaction is 110-180° C., preferably 120-150° C.; the time is 0.5-4 h, preferably 1-3 h; the reaction pressure is controlled to be ≤0.4 MPa, preferably 0.1-0.4 MPa.

[0045] In some embodiments of the present invention, after the reaction is completed, conventional post-treatment processes such as cooling treatment, neutralization treatment, and degassing treatment are also included. For example, after the reaction is completed, the temperature is lowered to 85°C, lactic acid is added to neutralize to pH = 6, and vacuum degassing is performed.

[0046] The technical solution of the present invention is further described below in conjunction with specific embodiments.

[0047] Example 1

[0048] The preparation method of the nonionic surfactant of this embodiment comprises the following steps:

[0049] Add 158g of 2-propylheptanol (1mol) and 0.5g of potassium hydroxide to the reactor, heat to 130°C, vacuum dehydrate for 1h, and control the moisture content in the reactor to be below 50ppm; slowly add 176g of ethylene oxide (4mol) to the reactor, control the pressure to <0.6MPa, and react for 2h; heat to 150°C, slowly add 74g of glycidol (1mol), control the pressure to <0.4Mpa, and react for 1h. After the reaction is completed, cool to 85°C, add lactic acid to neutralize to pH=6, vacuum degas, and obtain product 1 (m value is 4).

[0050] 13 CNMR (100MHz, CDCl3) δ104.5, 78.5, 70.6, 70.4, 69.1, 66.2, 37.9, 33.2, 31.6, 31.1, 26.9, 22.3, 20.2, 14.1, 14.0.

[0051] The hydroxyl value of the obtained product 1 is 279.8 mgKOH / g, and the calculated molecular weight is about 401.0 g / mol.

[0052] Example 2

[0053] The preparation method of the nonionic surfactant of this embodiment comprises the following steps:

[0054] Add 158g of 2-propylheptanol (1mol) and 1.6g of sodium hydroxide to the reactor, heat to 160°C, vacuum dehydrate for 1h, and control the moisture content in the reactor to be below 50ppm; slowly add 308g of ethylene oxide (7mol) to the reactor, control the pressure to <0.6MPa, and react for 6h; cool to 120°C, slowly add 74g of glycidol (1mol), control the pressure to <0.4Mpa, and react for 1.5h. After the reaction is completed, cool to 85°C, add acetic acid to neutralize to pH=6, vacuum degas, and obtain product 2 (m value is 7).

[0055] The 2-hydroxyl value of the obtained product is 209.7 mgKOH / g, and the calculated molecular weight is about 535.1 g / mol.

[0056] Example 3

[0057] The preparation method of the nonionic surfactant of this embodiment comprises the following steps:

[0058] Add 316g of 2-propylheptanol (2mol) and 1.8g of sodium methoxide to the reactor, heat to 145°C, vacuum dehydrate for 1h, and control the moisture content in the reactor to be below 50ppm; slowly add 440g of ethylene oxide (10mol) to the reactor, control the pressure to <0.6MPa, and react for 3.5h; cool to 135°C, slowly add 162g of glycidol (2.2mol), control the pressure to <0.4Mpa, and react for 3h. After the reaction is completed, cool to 85°C, add acetic acid to neutralize to pH=6, vacuum degas, and obtain product 3 (m value is 5).

[0059] The 3-hydroxyl value of the obtained product is 247.5 mgKOH / g, and the calculated molecular weight is about 453 g / mol.

[0060] Example 4

[0061] The preparation method of the nonionic surfactant of this embodiment comprises the following steps:

[0062] Add 237g of 2-propylheptanol (1.5mol) and 7.4g of potassium methoxide to the reactor, heat to 180°C, vacuum dehydrate for 1h, and control the moisture content in the reactor to be below 50ppm; slowly add 396g (9mol) of ethylene oxide to the reactor, control the pressure to <0.6MPa, and react for 8h; maintain 180°C, slowly add 116g of glycidol (1.6mol), control the pressure to <0.4Mpa, and react for 4h. After the reaction is completed, cool to 85°C, add lactic acid to neutralize to pH=6, vacuum degas, and obtain product 4 (m value is 6).

[0063] The hydroxyl value of the obtained product 4 is 152.6 mgKOH / g, and the calculated molecular weight is about 735 g / mol.

[0064] Example 5

[0065] The preparation method of the nonionic surfactant of this embodiment comprises the following steps:

[0066] Add 316g of 2-propylheptanol (2mol) and 9.1g of phosphazene catalyst to the reactor, heat to 140°C, vacuum dehydrate for 1h, and control the moisture content in the reactor to be below 50ppm; slowly add 440g of ethylene oxide (10mol) to the reactor, control the pressure to <0.6MPa, and react for 5h; maintain 140°C, slowly add 155g of glycidol (2.1mol), control the pressure to <0.4Mpa, and react for 2h. After the reaction is completed, cool to 85°C, add lactic acid to neutralize to pH=6, vacuum degas, and obtain product 5 (m value is 5).

[0067] The hydroxyl value of the obtained product is 251.5 mgKOH / g, and the calculated molecular weight is about 446 g / mol.

[0068] Example 6

[0069] The preparation method of the nonionic surfactant of this embodiment comprises the following steps:

[0070] Add 316g of 2-propylheptanol (2mol) and 0.028g of Zn / Co bimetallic catalyst to the reactor, heat to 150°C, vacuum dehydrate for 1h, and control the moisture content in the reactor to be below 50ppm; slowly add 440g of ethylene oxide (10mol) to the reactor, control the pressure to <0.6MPa, and react for 4h; maintain 150°C, slowly add 148g of propylene oxide (2mol), control the pressure to <0.4Mpa, and react for 1.5h. After the reaction is completed, cool to 85°C, add lactic acid to neutralize to pH=6, vacuum degas, and obtain product 6 (m value is 5).

[0071] The hydroxyl value of the obtained product 6 is 252.8 mgKOH / g, and the calculated molecular weight is about 443 g / mol.

[0072] Example 7

[0073] The preparation method of the nonionic surfactant of this embodiment comprises the following steps:

[0074] Add 158g of 2-propylheptanol (1mol) and 0.4g of potassium hydroxide to the reactor, heat to 130°C, vacuum dehydrate for 1h, and control the moisture content in the reactor to be below 50ppm; slowly add 132g of ethylene oxide (3mol) to the reactor, control the pressure to <0.6MPa, and react for 2h; heat to 150°C, slowly add 74g of glycidol (1mol), control the pressure to <0.4Mpa, and react for 1h. After the reaction is completed, cool to 85°C, add lactic acid to neutralize to pH=6, vacuum degas, and obtain product 7 (m value is 3).

[0075] The hydroxyl value of the obtained product 7 is 312.1 mgKOH / g, and the calculated molecular weight is about 359.5 g / mol.

[0076] Example 8

[0077] The preparation method of the nonionic surfactant of this embodiment comprises the following steps:

[0078] Add 158g of 2-propylheptanol (1mol) and 2.7g of sodium hydroxide to the reactor, heat to 160°C, vacuum dehydrate for 1h, and control the moisture content in the reactor to be below 50ppm; slowly add 660g of ethylene oxide (15mol) to the reactor, control the pressure to <0.6MPa, and react for 8h; cool to 120°C, slowly add 74g of glycidol (1mol), control the pressure to <0.4Mpa, and react for 1.5h. After the reaction is completed, cool to 85°C, add acetic acid to neutralize to pH=6, vacuum degas, and obtain product 8 (m value is 15).

[0079] The 8-hydroxyl value of the obtained product is 127.6 mgKOH / g, and the calculated molecular weight is about 879.3 g / mol.

[0080] Example 9

[0081] The preparation method of the nonionic surfactant of this embodiment comprises the following steps:

[0082] Add 316g of 2-propylheptanol (2mol) and 1.8g of sodium methoxide to the reactor, heat to 145°C, vacuum dehydrate for 1h, and control the moisture content in the reactor to be below 50ppm; slowly add 880g of ethylene oxide (20mol) to the reactor, control the pressure to <0.6MPa, and react for 3.5h; cool to 135°C, slowly add 162g of glycidol (2.2mol), control the pressure to <0.4Mpa, and react for 3h. After the reaction is completed, cool to 85°C, add acetic acid to neutralize to pH=6, vacuum degas, and obtain product 9 (m value is 10).

[0083] The hydroxyl value of the obtained product 9 is 190.6 mgKOH / g, and the calculated molecular weight is about 588.7 g / mol.

[0084] Comparative Example 1

[0085] The preparation method of the nonionic surfactant of Comparative Example 1 comprises the following steps:

[0086] Add 158g of 2-propylheptanol (1mol) and 0.5g of potassium hydroxide to the reactor, heat to 130°C, vacuum dehydrate for 1h, and control the moisture content in the reactor to be below 50ppm; slowly add 176g of ethylene oxide (4mol) to the reactor, control the pressure to <0.6MPa, and react for 2h. After the reaction is completed, cool to 85°C, add lactic acid to neutralize to pH=6, vacuum degas, and obtain product 10 (2-propylheptanol polyoxyethylene ether (4EO)).

[0087] Comparative Example 2

[0088] The preparation method of the nonionic surfactant of Comparative Example 2 comprises the following steps:

[0089] 316 g of 2-propylheptanol (2 mol) and 9.1 g of phosphazene catalyst were added to the reactor, the temperature was raised to 140° C., vacuum dehydration was carried out for 1 h, and the moisture content in the reactor was controlled to be below 50 ppm; 440 g (10 mol) of ethylene oxide was slowly added to the reactor, the pressure was controlled to be less than 0.6 MPa, and the reaction was carried out for 5 h. After the reaction was completed, the temperature was lowered to 85° C., lactic acid was added to neutralize to pH=6, and vacuum degassing was carried out to obtain the product 11 (2-propylheptanol polyoxyethylene ether (5EO).

[0090] Comparative Example 3

[0091] The preparation method of the nonionic surfactant of Comparative Example 3 comprises the following steps:

[0092] 316 g of 2-propylheptanol (2 mol) and 0.028 g of Zn / Co bimetallic catalyst were added to the reactor, the temperature was raised to 150°C, vacuum dehydration was carried out for 1 hour, and the moisture content in the reactor was controlled to be below 50 ppm; 440 g (10 mol) of ethylene oxide was slowly added to the reactor, the pressure was controlled to be less than 0.6 MPa, and the reaction was carried out for 4 hours. After the reaction was completed, the temperature was lowered to 85°C, lactic acid was added to neutralize to pH = 6, and vacuum degassing was carried out to obtain the product 12 (2-propylheptanol polyoxyethylene ether (5EO).

[0093] Comparative Example 4

[0094] Refer to the method of Example 1, except that the glycidol is replaced by an equal mass of propylene oxide, and other operations and conditions remain unchanged.

[0095] Performance Test:

[0096] The nonionic surfactants prepared in the examples and comparative examples were tested for alkali resistance, emulsification and metal cleaning ability. The test methods are as follows. The results are shown in Table 1.

[0097] Alkali resistance: Weigh 1g of sample, add it to 99g of aqueous solution with different sodium hydroxide concentrations, stir to dissolve, transfer to a colorimetric tube, and observe at 25℃ for 2h. The critical sodium hydroxide concentration at which floating oil appears is the alkali resistance concentration.

[0098] Emulsification: paraffin emulsification phase separation method was used for testing. 40 ml of liquid paraffin and 40 ml of 1 g / L emulsifier aqueous solution were poured into a beaker. After stirring and emulsifying at 1000 rpm for 1 min, the mixture was quickly poured into a measuring cylinder and the time taken to separate 10 ml of aqueous phase was recorded.

[0099] Metal oil removal rate: Tested in accordance with the national standard QBT2117-1995 for general water-based metal cleaning agents.

[0100] Table 1 Performance test results of embodiments and comparative examples

[0101] Group Alkali resistance g / L Emulsification / s Metal degreasing rate % Example 1 22 292 75.8 Example 2 56 365 74.9 Example 3 32 387 82.1 Example 4 42 302 76.4 Example 5 40 402 88.5 Example 6 42 394 92.5 Example 7 16 146 60.2 Example 8 86 298 59.6 Example 9 68 306 66.8 Comparative Example 1 8 108 52.8 Comparative Example 2 14 112 68.4 Comparative Example 3 16 123 72.3 Comparative Example 4 6 232 56.4

[0102] It can be seen from Table 1 that, compared with the comparative example, the nonionic surfactant provided by the present invention is a double-terminated hydroxyl polyoxyethylene polyoxypropylene ether, which makes the nonionic surfactant have excellent alkali resistance, emulsification and metal cleaning ability.

[0103] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A nonionic surfactant, characterized in that It has the structure shown in formula (1): Among them, the value of m is 3-15, preferably 4-7.

2. The nonionic surfactant according to claim 1, characterized in that The hydroxyl value is 126-321 mgKOH / g.

3. The nonionic surfactant according to claim 1, characterized in that The average molecular weight is 350-890 g / mol.

4. The nonionic surfactant according to claim 1, characterized in that The method is prepared by sequentially adding ethylene oxide and propylene oxide to a system including 2-propylheptanol and a catalyst to carry out reaction.

5. A method for preparing a nonionic surfactant according to any one of claims 1 to 4, characterized in that: The following steps are involved: 1) mixing 2-propylheptanol, a catalyst and ethylene oxide to carry out a primary reaction; 2) Adding propylene oxide to the reaction body of step 1) for secondary reaction to obtain the nonionic surfactant.

6. The preparation method according to claim 5, characterized in that: The catalyst is one or more of potassium hydroxide, sodium hydroxide, sodium methoxide, potassium methoxide, and phosphazene catalysts, preferably one or more of potassium hydroxide and phosphazene catalysts; Preferably, the mass of the catalyst is 0.02-1%, preferably 0.1-0.3%, of the total mass of the 2-propylheptanol, ethylene oxide and propylene oxide.

7. The preparation method according to claim 5, characterized in that: The catalyst is a Zn / Co bimetallic catalyst; Preferably, the mass of the catalyst is 0.002-0.02%, preferably 0.003-0.006%, of the total mass of 2-propylheptanol, ethylene oxide and propylene oxide.

8. The preparation method according to claim 5, characterized in that: The molar ratio of 2-propylheptanol to ethylene oxide is 1:3-15, preferably 1:4-7; and / or The molar ratio of the 2-propylheptanol to the glycidol is 1:1-1.2, preferably 1:1-1.

1.

9. The preparation method according to claim 5, characterized in that: Step 1) The temperature of the primary reaction is 120-190° C., preferably 130-160° C., and the time is 1-8 h, preferably 2-6 h; the reaction pressure is controlled to be ≤0.6 MPa.

10. The preparation method according to claim 5, characterized in that: Step 2) The temperature of the secondary reaction is 110-180° C., preferably 120-150° C., and the time is 0.5-4 h, preferably 1-3 h; the reaction pressure is controlled to be ≤0.4 MPa.

Images