Surfactants with improved emulsifying properties

Abstract

The present disclosure provides nonionic surfactants having the formula I:R-[A] x -[B] y A nonionic block copolymer structure of Formula I, wherein R is a C8-C30 alkyl, x is 8-20, y is 2-20, and [A] x The block is formed from propylene oxide, [B] y The blocks relate to nonionic surfactants formed from ethylene oxide and having a cloud point greater than 15°C.

Description

[Technical Field]

[0001] SUMMARY OF THE DISCLOSURE Embodiments of the present disclosure are directed to surfactants, particularly surfactants with improved emulsification performance. [Background technology]

[0002] The emulsification performance of surfactants is important in many areas, such as cleaning, detergency, and stain removal. Emulsification performance with vegetable or animal oils is crucial for detergency and degreasing performance. Although surfactants with various structures have been developed and commercialized to improve emulsification performance, there remains a need in the art for surfactants that can improve emulsification performance, especially when dealing with vegetable and / or animal oils. One approach to improving cleaning performance has been to use alkaline compounds in detergent formulations. However, these compounds can cause skin irritation in applications such as hand dishwashing. As a result, improving the emulsification performance of surfactants has proven to be a better option than using alkaline compounds. Therefore, there is a need in the art for nonionic extended surfactants that can provide strong emulsification performance, especially with vegetable or animal oils.

[0003] One area of ​​interest in improving emulsification performance has been what are called "extended surfactants." Compared to conventional surfactants, extended surfactants contain an intermediate polar spacer, such as a block formed from propylene oxide (PPO) or PPO-polyethylene oxide (PEO), inserted between the hydrophilic head and the hydrophobic tail. Research has shown that the PO group, which has weak lipophilic characteristics, can provide a smooth polar transition zone between the hydrophobic tail and the hydrophilic head, thereby providing better emulsification than conventional surfactants without a PO segment. However, it remains unclear which structure of extended surfactant can provide the best emulsification performance, and there is still a need in the art. Summary of the Invention

[0004] This disclosure relates to structure-performance relationships for the emulsification performance of nonionic surfactants with vegetable and animal oils, and demonstrates that specific nonionic surfactant structures have improved emulsification performance compared to other surfactants. Such improvements in nonionic surfactants can be beneficial in areas of emulsification performance in applications such as cleaning, detergency, and soil removal.

[0005] To that end, the present disclosure provides a nonionic surfactant comprising a nonionic block copolymer structure of Formula I: R-[A] x -[B] y Formula I In the formula, R is a C8 to C30 alkyl, x is 8 to 20, y is 2 to 20, and [A] x The block is formed from propylene oxide, [B] y The blocks are formed from ethylene oxide and have a cloud point greater than 15°C. For various embodiments, R can be a C12-C18 alkyl. For various embodiments, R can be a straight chain alkyl. For various embodiments, x can be 8-10. For various embodiments, y can be 4-10. For various embodiments, R can be a C12-C14 alkyl, x can be 8, and y can be 7. For various embodiments, R can be a C12-C14 alkyl, x can be 8, and y can be 9. For various embodiments, R can be 2-ethylhexyl, x can be 8, and y can be 4. For various embodiments, R can be a C8-C14 alkyl, x can be 8, and y can be 4. For various embodiments, R can be a C16-C18 alkyl, x can be 10, and y can be 10. [Brief explanation of the drawings]

[0006] [Figure 1A] 1 provides the emulsification performance of a formulation including Example 1, ethylene glycol phenyl ether solvent, and MIPA / DIPA amine according to the present disclosure. [Figure 1B] 1 provides the emulsification performance of a formulation including Example 1, ethylene glycol phenyl ether solvent, and MIPA / DIPA amine according to the present disclosure. [Figure 2A] 1 provides the emulsification performance of Comparative Example I, a formulation containing ethylene glycol phenyl ether solvent and MIPA / DIPA amines according to the present disclosure. [Figure 2B] 1 provides the emulsification performance of Comparative Example I, a formulation containing ethylene glycol phenyl ether solvent and MIPA / DIPA amines according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0007] The present disclosure relates to the emulsification performance of nonionic surfactants for mineral oils, vegetable oils, and animal oils (hereinafter referred to as "oils"). The structure of this nonionic surfactant provides improved emulsification performance compared to other surfactants. Such improvements in nonionic surfactants can be beneficial in areas of emulsification performance in applications such as cleaning, detergency, and stain removal. In particular, the nonionic surfactants of the present disclosure can be used in emulsions for removing oil from textile materials, including, but not limited to, fabrics, yarns, or other woven materials containing networks of natural or artificial fibers. For example, the nonionic surfactants of the present disclosure can be used in various cleaning processes, such as scouring or laundering (i.e., washing), for treating or pretreating textile fabrics. To achieve effective cleaning performance (i.e., effective removal of oil), the nonionic surfactant composition must possess effective emulsification performance, among other properties. Such properties enable the surfactant to penetrate the textile material and enclose the oil for removal.

[0008] Unless otherwise indicated, a range of numbers, eg, "2 to 10," is a real number and is inclusive of the numbers defining the range (eg, 2 and 10).

[0009] Unless otherwise indicated, ratios, percentages, parts, etc. are by weight.

[0010] As noted above, the present disclosure provides a nonionic surfactant, the nonionic surfactant comprising a nonionic block copolymer structure of Formula I: R-[A] x -[B] y Formula I In the formula, R is a C8 to C30 alkyl, x is 8 to 20, y is 2 to 20, and [A] x The block is formed from propylene oxide (PO), [B] y The blocks are formed from ethylene oxide (EO) and have a cloud point greater than 15° C. For various embodiments, preferably, the cloud point of Formula I is greater than 20° C. [A] x The propylene oxide used in forming the blocks can be 1,2-propylene oxide.

[0011] For various embodiments, R can be straight chain or branched chain. For various embodiments, R can be straight chain alkyl. Preferably, R is a C8 or higher alkyl. More preferably, R is a C12 or higher alkyl. In further embodiments, R can be a C12-C18 alkyl. For various embodiments, R can be a C12-C14 alkyl. For various embodiments, R can be a C16-C18 alkyl. For various embodiments, R can be 2-ethylhexyl.

[0012] For various embodiments, x is 8 or greater. For various embodiments, x can be 8 to 10. For various embodiments, y is greater than 2. For various embodiments, y can be 4 to 10. For more specific embodiments, R can be C12-C14 alkyl, x can be 8, and y can be 7. For various embodiments, R can be C12-C14, x can be 8, and y can be 9. For various embodiments, R can be 2-ethylhexyl, x can be 8, and y can be 4. For various embodiments, R can be C8-C14, x can be 8, and y can be 4. For various embodiments, R can be C16-C18, x can be 10, and y can be 10.

[0013] The nonionic block copolymer structure of Formula I can be obtained in a conventional manner by reacting an alcohol with an alkylene oxide, such as ethylene oxide (EO) and propylene oxide (PO), in the presence of a catalyst. The polymerization can be bulk polymerization or solution polymerization. Suitable catalysts for the polymerization of alkylene oxides can be found in the literature, for example, in FEBailey, Jr., Joseph V. Koleske, "Alkylene Oxides and Their Polymers," Marcel Dekker, New York, 1991, p. 35, and include anionic or basic catalysts, acidic or cationic catalysts, and coordination catalysts, such as potassium hydroxide (KOH), boron trifluoride, or double metal cyanide complex (DMC) catalysts, such as zinc hexacyanocobaltate.

[0014] The alkylene oxide is typically fed to a reactor containing a dry initiator and catalyst at temperatures varying from 50 to 160°C. Polymerization is usually considered complete when the pressure in the reactor returns to approximately the same pressure as before the alkylene oxide was fed. The catalyst can be neutralized and removed by known means, such as filtration, adsorption, and ion exchange, or left in the product, depending on the product and application.

[0015] The present disclosure further includes surfactant compositions comprising the nonionic surfactants of the present disclosure. For various embodiments, the surfactant compositions may include, but are not limited to, the nonionic surfactants of the present disclosure, water, one or more amines, and / or one or more solvents. For various embodiments, the surfactant compositions may include 5 to 30 weight percent (wt.%) of the nonionic surfactants of the present disclosure, 70 to 80 wt.% of water, 0 to 25 wt.% of one or more amines, and 0 to 25 wt.% of one or more solvents, where the wt.% are based on the total weight of the surfactant composition. Surfactant composition embodiments also include those in which water is initially absent, and the surfactant composition is subsequently mixed with water to produce, for example, an aqueous solution having a 0.1 to 10 wt.% solution of the surfactant composition.

[0016] For various embodiments, the one or more amines can include, but are not limited to, alkanolamines, alkylalkanolamines, and combinations thereof. For example, the one or more amines can be selected from the group consisting of monoisopropanolamine (MIPA), diisopropanolamine (DIPA), ethanolamine (MEA), triethanolamine (TEA), diethylethanolamine (DEEA), dimethylethanolamine (DMEA), methyldiethanolamine (MDEA), n-methylethanolamine (NMEA), and combinations thereof.

[0017] For various embodiments, the one or more solvents can include, but are not limited to, glycol ethers such as ethylene glycol phenyl ether, propylene glycol phenyl ether, diethylene glycol butyl ether, dipropylene glycol methyl ether, 1-(2-butoxy-1-methylethoxy)propan-2-ol, 1-methoxy-2-propyl acetate, [2-(2-methoxymethylethoxy)methylethoxy]propanol, ethylene glycol monobutyl ether, diethylene glycol monohexyl ether, diethylene glycol monobutyl ether, ethylene glycol monohexyl ether, and combinations thereof.

[0018] The surfactant composition may further contain other optional additives. Examples of such additives include those that do not interfere with the emulsification performance of the nonionic surfactant of the present disclosure and / or the surfactant composition containing the nonionic surfactant of the present disclosure. Examples of such additives include, but are not limited to, bases such as sodium hydroxide, oxidizing agents such as hydrogen peroxide, and other surfactants such as ionic surfactants and nonionic surfactants, alcohol ethoxy sulfate, linear alkyl benzene sulfonate, and alkyl diphenyl oxide disulfonate, among others known in the art.

[0019] In various embodiments, the surfactant compositions of the present disclosure, as provided herein, can be used in processes for washing and / or scrubbing oily soiled items. Such processes can be carried out at temperatures of 0 to 100°C and pressures of 0.5 to 1.5 kPa. For example, the surfactant compositions of the present disclosure can be used to scrub textile materials by contacting the textiles with a surfactant composition comprising a nonionic surfactant. [Example]

[0020] The following examples are provided for illustrative purposes only and are not intended to define or limit the embodiments in any way. In the examples (EX) and comparative examples (CE) of the present invention, various terms and designations for materials are used, including, for example, the following:

[0021] [Table 1]

[0022] [Table 2] a: Cloud point measured in a 10 wt% aqueous solution.

[0023] Synthesis example 1: Formula: LC 12~14 -(PO)8-(EO)7 (wherein, LC 12~14 is a linear C 12~14 Synthesis of a nonionic surfactant represented by 1 mole of LC 12~14 Alcohol and aqueous potassium hydroxide (45-50 wt%) were charged to a reactor. The KOH content was added at about 0.17 wt% based on the weight of the final product. The mixture was heated to about 50-60°C for 30 minutes. After vacuum stripping at about 80°C to control the moisture content to less than 1000 ppm, the mixture was then maintained at about 110-140°C. The first portion of 8 moles of PO (8 mole equivalents of LC) was then added. 12~14 When the pressure in the reactor returned to approximately the same as the pressure before the PO was added, 7 moles of EO (7 mole equivalents of LC) were added. 12~14The EO (equivalent to the alcohol) was slowly fed into the reactor, and the reactor temperature was maintained at 110-140°C. When the pressure in the reactor returned to approximately the same as before the EO was fed, the reaction was maintained at 110-140°C for an additional 2 hours to ensure complete consumption of the EO. After purging with N2 to remove residual oxides, the reactor was cooled to approximately 60°C at ambient pressure. Acetic acid was then added to the reactor to neutralize the KOH catalyst. After cooling to approximately 40°C, the desired product was obtained.

[0024] Synthesis example 2: Formula: LC 12~14 -(PO)8-(EO)9 (wherein, LC 12~14 - is a linear C 12~14 Synthesis of nonionic surfactants represented by the - moiety Synthesis Example 2 was carried out in the same manner as Synthesis Example 1, except that in step 1, LC 12~14 Alcohol was used as the starting alcohol, and the amounts of PO and EO fed to the reactor were changed accordingly.

[0025] Synthesis Example 3: Synthesis of a nonionic surfactant represented by the formula: 2-ethylhexyl-(PO)8-(EO)6.

[0026] Synthesis Example 3 was carried out in the same manner as Synthesis Example 1, except that 2-ethylhexanol was used as the starting alcohol in Step 1, and the amounts of PO and EO supplied to the reactor were changed appropriately.

[0027] Synthesis example 4: Formula: LC 8~14 -(PO)8-(EO)4 (wherein, LC 8~14 - is a linear C 8~14 Synthesis of nonionic surfactants represented by the - moiety Synthesis Example 4 was carried out in the same manner as Synthesis Example 1, except that in step 1, LC 8~14 Alcohol was used as the starting alcohol, and the amounts of PO and EO fed to the reactor were changed accordingly.

[0028] Synthesis example 5: Formula: LC 16~18 -(PO) 10 -(EO) 10 (In the formula, LC 16~18- is a linear C 16~18 Synthesis of nonionic surfactants represented by the - moiety Synthesis Example 5 was carried out in the same manner as Synthesis Example 1, except that in step 1, LC 16~18 Alcohol was used as the starting alcohol, and the amounts of PO and EO fed to the reactor were changed accordingly.

[0029] Synthesis Example 6: Formula: LC 12~14 -(PO) 12 -(EO)6(wherein, LC 12~14 - is a linear C 12~14 Synthesis of nonionic surfactants represented by the - moiety Synthesis Example 6 was carried out in the same manner as Synthesis Example 1, except that in step 1, LC 12~14 Alcohol was used as the starting alcohol, and the amounts of PO and EO fed to the reactor were changed accordingly.

[0030] Emulsifying performance evaluation of formulations To test emulsification performance, 400 μL of surfactant solution (1 wt% surfactant in water) was dispensed into a 1 mL vial, and then 150 μL of liquid oil was added on top of the solution. After capping, the vial was shaken for 60 seconds at intensity 7 by the automated shaker of a PICA II robot (an internal imaging robot equipped with a vial shaker). Images of the sample were then taken after shaking, and the grayscale value of the aqueous portion of the vial was measured using ImageJ [1. Rasband, WS, ImageJ, US National Institutes of Health, Bethesda, Maryland, USA, https: / / imagej.nih.gov / ij / , 1997-2018.] to quantify the formulation's emulsification performance. A higher grayscale value (indicating a whiter emulsion appearance) indicates better emulsification performance. In this study, the liquid oil was a mixture of corn oil, peanut oil, and sunflower seed oil in a 1:1:1 weight ratio unless otherwise specified.

[0031] Stain Removal Procedure - Detergency Test The stain removal performance (detergency test) of various surfactant solutions was also evaluated using polyester fabric soiled with olive oil. For the stain removal test, a Tergotometer (model TRG 800i, Copley) was used with the following process parameters: dosage: 0.4 g / L; temperature: 30°C; agitation speed: 120 rpm; wash time: 20 minutes; water: water hardness 120 ppm; swatches: the swatches used in this study are listed in Table 1 (size 5 cm × 5 cm).

[0032] The color of the dry swatches was measured before and after washing with a spectrophotometer (Konica Minolta Spectrophotometer CM-3600A). Each piece was measured on the soiled side. The output of the color measurement was L * , a * , and b * The detergency was calculated based on the following formula:

[0033]

number

[0034] Standard polyester fabrics stained with olive oil were used, and detailed information on the stained fabrics is shown in Table 3.

[0035] [Table 3]

[0036] Examples to demonstrate the emulsifying performance of surfactants

[0037] [Table 4]

[0038] Examples 1-6 shown in Table 4 demonstrate better emulsification performance than the comparative examples, with higher grayscale values ​​indicating better performance. From this data, it can be seen that the nonionic block copolymer structures of Formula I provided herein: R-[A]x-[B]y Formula I It can be seen that nonionic surfactants having the same hydrophobic tail can provide better emulsification performance for vegetable oils. For example, with the same hydrophobic tail, a more hydrophobic surfactant (lower cloud point) tends to provide better emulsification performance for vegetable oil mixtures. However, there are some differences between the triblock structure (R-[EO]z-[PO]x-[EO]y) and the diblock counterpart (R-[PO]x-[EO]y) of the present disclosure. When the surfactants have similar hydrophobicity (similar cloud points), those with diblock structures tend to provide better emulsification performance. For example, Example 2 (C12-14-PO8-EO9) (1 wt % aqueous solution) with a cloud point of 40°C gave better emulsification performance than both Comparative Example D (C12-14-EO4-PO8-EO4, cloud point = 34°C, 1 wt % aqueous solution) and Comparative Example E (C12-14-EO4-PO8-EO6, cloud point = 42°C, 1 wt % aqueous solution), indicating that the introduction of internal EO blocks may impair emulsification performance.

[0039] A comparison of Comparative Example I and Example 3 shows that when only longer internal PO segments are introduced (the number of PO units in Comparative Example I is 5, and the number of PO units in Example 3 is 8), only a slight improvement is observed. This comparison shows that both longer hydrophobic tails and longer PO segments in the general structure are beneficial in providing good emulsification performance, and furthermore, that it is beneficial for the PO segments to be directly connected to the hydrophobic tail without extra EO units. When extra internal EO units are present, surfactants tend to give poorer emulsification performance, even if they have longer hydrophobic tails such as Comparative Example G (C16-18-EO4.42-PO13.74-EO5 with a cloud point of 28°C).

[0040] The nonionic surfactants of the present disclosure are also further supported by comparison with the surfactants of Comparative Examples P and Q. Because the surfactants of Comparative Examples P and Q have longer hydrophobic tails (linear C8-14 alcohols with an average carbon number of approximately C10) than the surfactant of Comparative Example I (2-ethylhexanol), when longer PO blocks are incorporated, a more significant improvement in emulsification performance is observed when comparing performance between Comparative Examples Q, M, and O. For example, the performance of Comparative Example O (12 PO units) is higher than Comparative Example M (8 PO units), which is higher than Comparative Example Q (3 PO units), which is in good agreement with the number of PO units.

[0041] The removal of vegetable oil on polyester also demonstrates the better performance of the surfactants of the present invention having the structure of Formula I, as further shown in Table 5, which also confirms the positive emulsification performance for stain removal, especially for polyester fabrics.

[0042] As can be seen from Table 5, Examples 1 and 2 provide much better stain removal performance than Comparative Examples I, P, and Q.

[0043] [Table 5]

[0044] To further demonstrate the performance of the nonionic surfactant of the present disclosure, its performance in the above formulation system was compared with other surfactants, solvents, and amines. 1% aqueous solutions containing surfactants, solvents, and amines were prepared according to the dosages in Table 6, and the solution samples were thoroughly mixed to form homogeneous solutions at room temperature (23°C). Their emulsification performance was then evaluated using the same procedure as described in "Formulation emulsification performance evaluation."

[0045] [Table 6-1]

[0046] [Table 6-2]

[0047] In Figures 1A and 1B, higher values ​​(right axis of the figure) indicate better performance; therefore, the closer the data point is to the right axis of the figure, the better the emulsification.

[0048] For comparison, the performance of another nonionic extending surfactant, Comparative Example I, was also evaluated and is shown in Figures 2A and 2B.

[0049] In both Figures 1A-1B and 2A-2B, it is clearly seen that formulations containing surfactants of the present invention can provide good emulsification performance across the entire dosage range, while for conventional nonionic extending surfactants such as Comparative Example I, only formulations with higher amine dosages can provide good performance; consequently, the performance comparisons herein demonstrate the superior performance of the nonionic extending surfactants of the present invention having general structure 1.

[0050] Based on the above results, it can be concluded that nonionic surfactants satisfy the following three structural characteristics: a longer hydrophobic tail (8 or more carbon atoms, more preferably 12 or more carbon atoms), a longer propylene oxide (PO) unit (8 or more carbon atoms), and a PO unit directly connected to the hydrophobic tail.

Claims

1. 1. A nonionic surfactant having the formula I: R-[A] ｘ -[B] ｙ Formula I a nonionic block copolymer structure of In the formula, R is a C8 to C30 alkyl, x is 8 to 20, and y is 2 to 20, and [A] ｘ The block is formed from propylene oxide, [B] ｙ A nonionic surfactant in which the blocks are formed from ethylene oxide and have a cloud point greater than 15°C.

2. 2. The nonionic surfactant of claim 1, wherein R is a C12 to C18 alkyl.

3. 2. The nonionic surfactant of claim 1, wherein R is a linear alkyl.

4. 2. The nonionic surfactant according to claim 1, wherein x is 8 to 10.

5. The nonionic surfactant according to any one of claims 1 to 4, wherein y is 4 to 10.

6. 2. The nonionic surfactant of claim 1, wherein R is C12-C14, x is 8, and y is 7.

7. 2. The nonionic surfactant of claim 1, wherein R is C12-C14, x is 8, and y is 9.

8. 2. The nonionic surfactant of claim 1, wherein R is 2-ethylhexyl, x is 8, and y is 4.

9. 2. The nonionic surfactant of claim 1, wherein R is C8 to C14, x is 8, and y is 4.

10. 2. The nonionic surfactant of claim 1, wherein R is C16-C18, x is 10, and y is 10.

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