Hydrotrope cleaning composition

Abstract

Disclosed is a cleaning composition comprising water, a surfactant, and a hydrotrope having structure (I) wherein m of structure (I) is from 1.0 to 1.2 according to 13C nuclear magnetic resonance measurement.

Description

BACKGROUND OF THE INVENTION FIELD OF THE INVENTION

[0001] The present disclosure relates to cleaning compositions, and more particularly to cleaning compositions comprising hydrotropes.

[0002] Introduction

[0003] In cleaning applications, a hydrotrope is a compound that enables a surfactant to dissolve into a formulation at a higher concentration than the formulation would normally support. Hydrotropes are useful materials because in certain situations such as high alkalinity (i.e., 10 weight percent (“wt%”) or even higher NaOH in a cleaning formulation), surfactants have low solubility in the cleaning composition. Low solubility of surfactants in the cleaning composition means that the cleaning composition may not only lack sufficient detergency due to a low surfactant loading, but may also exhibit a cloudy appearance (due to surfactant insolubility in the formulation), phase separation, and instability. Thus, hydrotropes can be considered coupling agents or solubilizers between surfactants and cleaning compositions. A measure of how well a hydrotrope couples a nonionic surfactant (the most common type of surfactant in industrial cleaning formulations) to an alkaline composition is the amount of hydrotrope required to increase the cloud point of the cleaning composition. A hydrotrope is considered to have coupling efficacy if a 1 wt% nonionic surfactant solution having an initial cloud point of 35° C. in a 5 wt% NaOH aqueous solution at 23° C. changes from cloudy (i.e., insoluble) to clear upon addition of only 2.5 wt% hydrotrope.

[0004] Hydrotropes may also affect other properties of the cleaning composition. For example, some hydrotropes are known to produce stable foams, which is generally disadvantageous in industrial cleaning environments. For example, some alkyl polyglucosides can be used as hydrotropes, but as explained in U.S. Patent No. 3,219,656, alkyl polyglucosides “show highly stable foams and act as foam stabilizers for other surfactants”. Stable foams in industrial cleaning applications present problems due to additional rinse time and water consumption as well as foam interfering with the machines of the cleaning system. The Ross-Miles Foam Height test is a standard foam test method for amphiphilic materials, in which an aqueous solution of a surfactant or hydrotrope sample is poured into a test tube and the initial height of any foam is compared to the height of the foam after 5 minutes of foam dissipation. Generally, surfactants or hydrotropes that exhibit an initial foam height of less than 50 mm (at a 0.1 wt% aqueous solution) and a foam height of less than 20 mm after 5 minutes are considered low-foaming surfactants or hydrotropes.

[0005] Another increasingly important trend is the conversion to environmentally friendly hydrotropes. Manufacturers of cleaning solutions are increasingly considering components for use in cleaning solutions that are eco-friendly and biodegradable. Traditional hydrotropes include phosphate types and (di)sulfonate types, both of which are subject to increasing scrutiny. For example, phosphorus-containing hydrotropes are alleged to cause increased eutrophication of waterways, while some sulfonate-type hydrotropes are not readily biodegradable or have strong eye / skin irritation.

[0006] In view of these competing interests, it has surprisingly been found that cleaning compositions utilizing alkyl polyglucoside hydrotropes are not only effective under the above guidance, but also exhibit an initial foam of less than 50 mm and a foam after 5 minutes of less than 20 mm when tested at 0.1 wt% according to the Ross-Miles foam height test, and are readily biodegradable. Summary of the Invention

[0007] The inventors of the present application have found that cleaning compositions utilizing alkyl polyglucoside hydrotropes are not only effective under the above guidance, but also exhibit an initial foam of less than 50 mm and a foam after 5 minutes of less than 20 mm when tested at 0.1 wt% according to the Ross-Miles foam height test, and are readily biodegradable.

[0008] The present disclosure is a discovery that when utilizing a hydrotrope having structure (I), the cleaning composition can achieve the benefits mentioned above.

[0009]

[0010] Where m is from 1.0 to 1.2. As mentioned above, alkyl glucosides are commonly used in applications requiring high and stable foams. Surprisingly, when tested at 0.1 wt% according to the Ross-Miles foam height test, the branched-chain alkyl 2-octanol in structure (I) with m being 1.0 - 1.2 exhibits an initial foam of 10 mm and a foam after 5 minutes of 0 mm. Without being bound by theory, it is believed that the mildly branched nature of structure (I) prevents the hydrotrope from stabilizing the foam generated by stirring the cleaning composition comprising the hydrotrope. It is believed that the combination of the low m value with the 2-octyl of structure (I) also places the hydrophilic-lipophilic balance of the hydrotrope at a value that provides an excellent increase in cloud point, thereby enabling the hydrotrope to successfully dissolve the surfactant and couple the surfactant to the cleaning composition. Finally, compared to phosphate or sulfonate hydrotropes, the use of alkyl glucoside hydrotropes does not have a negative impact on the biodegradability and eco-friendly nature of the cleaning composition to which it is added.

[0011] According to a first aspect of the present disclosure, the cleaning composition comprises water, a surfactant, and a hydrotrope having structure (I), wherein according to 13 13C nuclear magnetic resonance measurements, m of structure (I) is from 1.0 to 1.2.

[0012] According to a second aspect of the present disclosure, the surfactant is a nonionic surfactant.

[0013] According to a third aspect of the present disclosure, the cleaning composition comprises from 0.01 wt% to 10.0 wt% of the surfactant, based on the total weight of the cleaning composition.

[0014] According to a fourth aspect of the present disclosure, the cleaning composition comprises an alkali metal salt.

[0015] According to a fifth aspect of the present disclosure, the cleaning composition comprises 0.1 wt% or more of NaOH, based on the total weight of the cleaning composition.

[0016] According to a sixth aspect of the present disclosure, the cleaning composition comprises from 0.01 wt% to 20.0 wt% of the hydrotrope.

[0017] According to a seventh aspect of the present disclosure, the cleaning composition comprises from 0.5 wt% to 10.0 wt% of the hydrotrope, based on the total weight of the cleaning composition.

[0018] According to an eighth aspect of the present disclosure, m of structure (I) is 1.0. DETAILED DESCRIPTION

[0019] As used herein, the term "and / or" when used in a list of two or more items means that any of the listed items can be used alone or any combination of two or more of the listed items can be used. For example, if a composition is described as containing components A, B, and / or C, the composition can contain A alone; B alone; C alone; A and B in combination; A and C in combination; B and C in combination; or A, B, and C in combination.

[0020] Unless otherwise specified, all ranges include the endpoints.

[0021] As used herein, unless otherwise specified, the term weight percent ("wt%") means the weight percentage of a component based on the total weight of the glycol composition.

[0022] As used herein, the Chemical Abstracts Service Registry Number ("CAS#") refers to the unique numerical identifier that has most recently been assigned by the Chemical Abstracts Service to a chemical compound since the priority date of this document.

[0023] Cleaning composition

[0024] The cleaning composition of the present disclosure comprises water, a surfactant, and a hydrotrope having structure (I):

[0025]

[0026] wherein m of structure (I) is from 1.0 to 1.2 as measured by 13 13C nuclear magnetic resonance. The cleaning composition comprises 70 wt% to 90 wt% water based on the total weight of the cleaning composition. For example, the cleaning composition may comprise 70 wt% or more, or 72 wt% or more, or 74 wt% or more, or 76 wt% or more, or 78 wt% or more, or 80 wt% or more, or 82 wt% or more, or 84 wt% or more, or 86 wt% or more, or 88 wt% or more, or 90 wt% or more, or 92 wt% or more, or 94 wt% or more, or 96 wt% or more, or 98 wt% or more of water, while at the same time, 99 wt% or less, or 98 wt% or less, or 96 wt% or less, or 94 wt% or less, or 92 wt% or less, or 90 wt% or less, or 88 wt% or less, or 86 wt% or less, or 84 wt% or less, or 82 wt% or less, or 80 wt% or less, or 78 wt% or less, or 76 wt% or less, or 74 wt% or less, or 72 wt% or less of water.

[0027] Surfactant

[0028] The cleaning composition comprises a surfactant. As used herein, the term "surfactant" means a material capable of reducing the interfacial energy between two dissimilar substances. The surfactant may be an anionic surfactant, a nonionic surfactant, a cationic surfactant, an amphoteric surfactant, and / or a combination thereof. The hydrophobic moiety of the surfactant may be branched or straight-chain, primary or secondary alkyl, saturated or unsaturated, or aryl-containing (poly)alkyl. In one specific example, the surfactant may be a branched alcohol ethoxylate. Commercially available examples of the surfactant may include ECOSURF TM LFE-635 from The Dow Chemical Company of Midland, Michigan; or widely commercially available examples of primary C12-14 alcohol ethoxylates, such as TERGITOL TM 26-L-9.

[0029] The cleaning composition may comprise from 0.01 wt% to 10.0 wt% of a surfactant based on the total weight of the cleaning composition. For example, the cleaning composition may comprise 0.01 wt% or more, or 0.1 wt% or more, or 0.5 wt% or more, or 1.0 wt% or more, or 1.5 wt% or more, or 2.0 wt% or more, or 2.5 wt% or more, or 3.0 wt% or more, or 3.5 wt% or more, or 4.0 wt% or more, or 4.5 wt% or more, or 5.0 wt% or more, or 5.5 wt% or more, or 6.0 wt% or more, or 6.5 wt% or more, or 7.0 wt% or more, or 7.5 wt% or more, or 8.0 wt% or more, or 8.5 wt% or more, or 9.0 wt% or more, or 9.5 wt% or more of a surfactant, while at the same time, 10.0 wt% or less, or 9.5 wt% or less, or 9.0 wt% or less, or 8.5 wt% or less, or 8.0 wt% or less, or 7.5 wt% or less, or 7.0 wt% or less, or 6.5 wt% or less, or 6.0 wt% or less, or 5.5 wt% or less, or 5.0 wt% or less, or 4.5 wt% or less, or 4.0 wt% or less, or 3.5 wt% or less, or 3.0 wt% or less, or 2.5 wt% or less, or 2.0 wt% or less, or 1.5 wt% or less, or 1.0 wt% or less, or 0.1 wt% or less, or 0.05 wt% or less of a surfactant.

[0030] Hydrotrope

[0031] The cleaning composition comprises a hydrotropic agent having structure (I):

[0032]

[0033] wherein according to 13 13C nuclear magnetic resonance measurements, m of structure (I) is 1.0 to 1.2. For example, according to 13 13C nuclear magnetic resonance measurements, m of structure (I) may have an average value of 1.0 or greater, or 1.05 or greater, or 1.10 or greater, or 1.15 or greater, while at the same time, 1.20 or less, or 1.15 or less, or 1.10 or less, or 1.05 or less. The m moiety of structure (I) may also be referred to as a glucose repeat unit.

[0034] The cleaning composition may comprise from 0.01 wt% to 20.0 wt% of a hydrotropic agent, based on the total weight of the cleaning composition.For example, the cleaning composition can contain 0.01 wt% or more, or 0.1 wt% or more, or 0.5 wt% or more, or 1.0 wt% or more, or 1.5 wt% or more, or 2.0 wt% or more, or 2.5 wt% or more, or 3.0 wt% or more, or 3.5 wt% or more, or 4.0 wt% or more, or 4.5 wt% or more, or 5.0 wt% or more, or 5.5 wt% or more, or 6.0 wt% or more, or 6.5 wt% or more, or 7.0 wt% or more, or 7.5 wt% or more, or 8.0 wt% or more, or 8.5 wt% or more, or 9.0 wt% or more, or 9.5 wt% or more, 10.0 wt% or more, or 10.5 wt% or more, or 11.0 wt% or more, or 11.5 wt% or more, or 12.0 wt% or more, or 12.5 wt% or more, or 13.0 wt% or more, or 13.5 wt% or more, or 14.0 wt% or more, or 14.5 wt% or more, or 15.0 wt% or more, or 15.5 wt% or more, or 16.0 wt% or more, or 16.5 wt% or more, or 17.0 wt% or more, or 17.5 wt% or more, or 18.0 wt% or more, or 18.5 wt% or more, or 19.0 wt% or more, or 19.5 wt% or more, based on the total weight of the cleaning composition, while, at the same time, 20.0 wt% or less, or 19.5 wt% or less, or 19.0 wt% or less, or 18.5 wt% or less, or 18.0 wt% or less, or 17.5 wt% or less, or 17.0 wt% or less, or 16.5 wt% or less, or 16.0 wt% or less, or 15.5 wt% or less, or 15.0 wt% or less, or 14.5 wt% or less, or 14.0 wt% or less, or 13.5 wt% or less, or 13.0 wt% or less, or 12.5 wt% or less, or 12.0 wt% or less, or 11.5 wt% or less, or 11.0 wt% or less, or 10.5 wt% or less, or 10.0 wt% or less, or 9.5 wt% or less, or 9.0 wt% or less, or 8.5 wt% or less, or 8.0 wt% or less, or 7.5 wt% or less, or 7.0 wt% or less, or 6.5 wt% or less, or 6.0 wt% or less, or 5.5 wt% or less, or 5.0 wt% or less, or 4.5 wt% or less, or 4.0 wt% or less, or 3.5 wt% or less, or 3.0 wt% or less, or 2.5 wt% or less, or 2.0 wt% or less, or 1.5 wt% or less, or 1.0 wt% or less, or 0.1 wt% or less, or 0.05 wt% or less of a hydrotropic agent.

[0035] Alkali metal salt

[0036] The cleaning composition may comprise an alkali metal salt. For example, the alkali metal salt may be an alkali metal or alkaline earth metal hydroxide. The alkali metal salt may be selected from the group consisting of sodium hydroxide (i.e., NaOH), potassium hydroxide, and / or combinations thereof or combinations thereof with certain amines such as monoethanolamine.

[0037] The cleaning composition may comprise from 0.01 wt.% to 40.00 wt.% of an alkali metal salt based on the total weight of the cleaning mixture. For example, the cleaning mixture may comprise 0.01 wt.% or more, or 0.1 wt.% or more, or 0.50 wt.% or more, or 1.00 wt.% or more, or 1.50 wt.% or more, or 2.00 wt.% or more, or 2.50 wt.% or more, or 5.00 wt.% or more, or 7.50 wt.% or more, or 10.00 wt.% or more, or 12.50 wt.% or more, or 15.00 wt.% or more, or 17.50 wt.% or more, or 20.00 wt.% or more, or 22.50 wt.% or more, or 25.00 wt.% or more, or 27.50 wt.% or more, or 30.00 wt.% or more, or 32.50 wt.% or more, or 35.00 wt.% or more, or 37.50 wt.% or more of an alkali metal salt, while at the same time, 40.00 wt.% or less, or 37.50 wt.% or less, or 35.00 wt.% or less, or 32.50 wt.% or less, or 30.00 wt.% or less, or 27.50 wt.% or less, or 25.00 wt.% or less, or 22.50 wt.% or less, or 20.00 wt.% or less, or 17.50 wt.% or less, or 15.00 wt.% or less, or 12.50 wt.% or less, or 10.00 wt.% or less, or 7.50 wt.% or less, or 5.00 wt.% or less, or 2.50 wt.% or less, or 2.00 wt.% or less, or 1.50 wt.% or less, or 1.00 wt.% or less, or 0.50 wt.% or less of an alkali metal salt.

[0038] Additive

[0039] The cleaning composition may comprise one or more additives. The cleaning composition may comprise from 0 wt% to 20 wt% of each additive, based on the total weight of the cleaning composition. For example, the cleaning composition may comprise 0 wt% or more, or 1 wt% or more, or 2 wt% or more, or 3 wt% or more, or 4 wt% or more, or 5 wt% or more, or 6 wt% or more, or 7 wt% or more, or 8 wt% or more, or 9 wt% or more, or 10 wt% or more, or 11 wt% or more, or 12 wt% or more, or 13 wt% or more, or 14 wt% or more, or 15 wt% or more, or 16 wt% or more, or 17 wt% or more, or 18 wt% or more, or 19 wt% or more, while at the same time 20 wt% or less, or 19 wt% or less, or 18 wt% or less, or 17 wt% or less, or 16 wt% or less, or 15 wt% or less, or 14 wt% or less, or 13 wt% or less, or 12 wt% or less, or 11 wt% or less, or 10 wt% or less, or 9 wt% or less, or 8 wt% or less, or 7 wt% or less, or 6 wt% or less, or 5 wt% or less, or 4 wt% or less, or 3 wt% or less, or 2 wt% or less, or 1 wt% or less of the additive. The additives may include one or more diluents, such as propylene glycol and / or other diluents. The additives may include one or more defoamers and / or high molecular weight polyglycols. The additives may include one or more water-soluble acrylic copolymers. The additives may include one or more chelating agents, such as ethylenediaminetetraacetic acid (“EDTA”), citric acid, potassium citrate, sodium citrate, tetrasodium ethylenediaminetetraacetate, tetrasodium ethylenediaminetetraacetate, tetrasodium ethylenediaminetetraacetate, diammonium ethylenediaminetetraacetate, tetrasodium ethylenediaminetetraacetate, tetrasodium ethylenediaminetetraacetate tetrahydrate, disodium ethylenediaminetetraacetate tetrahydrate, ethylenediaminetetraacetic acid, disodium ethylenediaminetetraacetate dihydrate, disodium ethylenediaminetetraacetate dihydrate, pentasodium diethylenetriaminepentaacetate, pentasodium diethylenetriaminepentaacetate, trisodium n-(hydroxyethyl)-ethylenediaminetriacetate, disodium n-(hydroxyethyl)-ethylenediaminetriacetate iron, ethylenediaminetetraacetic acid, and combinations thereof.

[0040] Examples

[0041] Materials

[0042] The materials mentioned below are used to form the inventive examples (“IE”) and comparative examples (“CE”) of the present invention.

[0043] 2OG is 2-octyl glucoside with a structure (I) having an m value of 1.0. 2OG is formed by performing the following steps. First, 2-octanol (36.7 g, 0.282 mol, 1.1 equivalents) and D-glucose pentaacetate (100 g, 0.256 mol, 1 equivalent) are dissolved in 300 mL of dichloromethane (DCM) at 23 °C to form a solution. Next, boron trifluoride etherate (40 g, 0.282 mol, 1.1 equivalents) is added dropwise to the solution over a period of 3 minutes. The solution is magnetically stirred at 23 °C for 48 hours. Next, 150 ml of saturated sodium bicarbonate solution is added to the solution, and the resulting two-phase mixture is shaken until no more effervescence is observed. Then, the two-phase mixture is transferred to a separatory funnel for separation. Next, the organic phase is collected, and the aqueous phase is washed with 100 mL of DCM. The separated organic phase is combined with the previous organic phase. Next, 60 g of sodium sulfate powder is added to the combined organic phase to remove residual water. The resulting organic phase is magnetically stirred for 30 minutes. Next, the formed solid is filtered, and the organic solvent (DCM) is removed from the dried organic phase under reduced pressure of about 20 KPa at 23 °C to obtain a crude product in the form of a yellow oil. The crude product is dissolved in a mixed solvent (10:1 petroleum ether / ethyl acetate) and purified by a silica gel column (10:1 petroleum ether / ethyl acetate by volume) to remove impurities. Then, the mixed solvent is distilled off by a rotary evaporator at 30 °C under 20 KPa to obtain a yellow solid product (18 g). Then the yellow solid product is subjected to a deacetylation process. 10 grams of the yellow solid product is dissolved in 100 mL of methanol. Next, 30 g of an anion exchange resin Amberlite 400(OH) is added all at once at 23 °C to form a slurry. The slurry is kept under magnetic stirring overnight at 23 °C. After stirring, all the solids are collected by filtration and then rinsed with methanol. Methanol is removed by rotary evaporation at 35 °C under 20 KPa to obtain 2-octyl glucoside having the structure (I).

[0044] APG is isooctyl glucoside with a CAS number of 125590-73-0 and has a structure (II)

[0045]

[0046] where n is 1.4 (i.e., repeating glucose units). APG can be GREENAPG TM IC-08 is commercially obtained from Shanghai Fine Chemical Co., Ltd., Shanghai, CHINA in Shanghai, China.

[0047] SURF is a nonionic branched alcohol alkoxylate surfactant with a cloud point of 35 °C and can be ECOSURF TM LFE-635 was commercially obtained from The Dow Chemical Company, Midland, Michigan.

[0048] PG is 2-octyl polyglucoside with structure (I) having an m value greater than 1.5. PG was formed by performing the following steps. First, 2-octanol (65.1 g, 0.5 mol, 5 equivalents) and D-glucose (18.0 g, 0.1 mol, 1 equivalent) were added to a 100 mL flask. Then, p-toluenesulfonic acid (0.344 g, 0.002 mol, 0.02 equivalents) was added to the flask and the mixture was heated to 110 °C in an oil bath with magnetic stirring. A vacuum was slowly applied to the flask and maintained at 50 kPa to 70 kPa to remove the water generated during the reaction and adjusted to avoid evaporation of 2-octanol. The reaction was run for 6 hours. After the reaction was complete, the pH was adjusted to 7 - 8 with 2 mol / L aqueous NaOH solution after stopping the vacuum and cooling to 23 °C. Then, the excess 2-octanol (<1 KPa) was removed at 90 °C. A yellow or brown waxy solid was obtained as the final product. According to 13 13C nuclear magnetic resonance measurements, the m value in structure (I) of 2-octyl polyglucoside is 2.35.

[0049] NaOH is an aqueous solution of 80 g of sodium hydroxide per liter of water.

[0050] Sample preparation and testing methods

[0051] Hydrotropic performance test: First, a hydrotropic aqueous solution with an active concentration of 50 wt.% was prepared. Based on the total amount of each component in the final test solution (10 mL): 0.5 g of NaOH solid was added to 8.9 g of water or 8.4 g of water; after it was completely dissolved, then 0.5 g or 1.0 g of the hydrotropic aqueous solution (50 wt.%) was added to the 5 wt.% aqueous NaOH solution, aiming for a hydrotropic with an active concentration of 2.5 wt.% or 5 wt.% in the final test solution. Once it was thoroughly mixed, 0.1 g of SURF was added to the 1 wt.% active concentration mixture. The test tube was placed in a hot water bath. When the appearance of the test solution became turbid, the tube was removed, and then we recorded the temperature at which the solution changed from turbid to clear as its cloud point. Then, such operations were repeated three times to obtain the average cloud point.

[0052] Ross-Miles Foam Test: This test is conducted according to the foaming test of Chinese national standard GB / T 13173-2008. Prepare an aqueous solution of 0.1 wt.% active solubilizer with deionized water. Rinse the Ross-Miles test tube with deionized water and the pre-prepared sample solution (0.1 wt% active aqueous solution). Pour 50 mL of the sample solution into the test tube. Once no foaming is observed in this first 50 mL of the sample solution, add 200 mL of the sample solution via a dropping pipette. Then, open the stopcock of the dropping pipette to allow the solution to flow down into the test tube. Once the flow of the solution ends, record the initial foam height as the initial height. At the end of 5 min, record the foam height as the final height.

[0053] Recirculating Bubble Foam Test: Use a special recirculating foaming machine. The entire test is conducted at 23 °C. Prepare an aqueous solution of approximately 250 mL of surfactant (0.1 wt% active SURF) in a beaker. Keep stirring the solution until the SURF is completely dissolved in water, and then pour it into a glass test bottle. This pouring operation may generate some foam, and start the machine after the bubbles disappear. The initial volume reading is 5 mL, which represents the volume of the initial liquid (the total volume of foam and liquid is recorded during the test; the final volume reading may be less than 5 mL because the liquid remains on the wall at the end of the test). The total test duration is 5 minutes: Start the machine in the first minute and record the total volume readings at 15 s, 30 s, and 60 s. Sixty seconds after the machine is turned off, record the total volumes at 75 s, 90 s, 2 min, 3 min, 4 min, and 5 min respectively.

[0054] 13 13C Nuclear Magnetic Resonance: Dissolve the sample (∼0.3 g) in D 2 2O (0.8 mL) at 23 °C to obtain a homogeneous solution. Add the resulting solution to a 5 mm tube and send it for NMR analysis. Obtain all NMR data on a Bruker AVANCE 13 II 400 MHz spectrometer operating at a 13C resonance frequency of 100.6 MHz at 23 °C. Use a 5 mm BBO probe. Use Zgig as the TM pulse program for 13C NMR, where the observation pulse is 90 degrees. Set the recycle delay to 14 s. Scan the sample 4000 times. Calculate the number of glucose units (PD) by integrating the corresponding peaks in the 13C NMR spectrum using Equations 1-3. 13 C NMR spectrum. 13 Reacted glucose = Total glucose (CH signals in 65 - 59 ppm) - Free glucose (CH, 95.9 ppm, 92.1 ppm) Equation (1)

[0055] Reaction glucose = Total glucose (CH signals in 65 - 59 ppm) - Free glucose (CH, 95.9 ppm, 92.1 ppm) Equation (1) 2 Signal) - Free glucose (CH, 95.9 ppm, 92.1 ppm) Equation (1)

[0056] Reacted 2 - octanol = Total 2 - octanol (CH 3 , 13.6 ppm) - Free 2 - octanol (CH2, 38.8 ppm) Equation (2)

[0057] Pd = Reacted glucose / Reacted 2 - octanol Equation (3)

[0058] Results

[0059] Table 3 provides the results of the hydrotropic agent performance tests conducted in a 5 wt% NaOH alkaline environment, Table 4 provides the results of the Ross - Miles foam tests, and Table 5 provides the results of the cyclic foam tests at an active content of 0.5 wt%.

[0060] Table 3

[0061]

[0062] *: Appearance turbid at 23 °C.

[0063] Now referring to Table 3, the blank example demonstrates that SURF (1 wt%) is insoluble in a 5% wt NaOH aqueous solution without a hydrotropic agent. IE1 demonstrates that, relative to CE1 and CE2, using a hydrotropic agent with structure (I) (having a glucose repeat unit value of 1.0) provides the largest increase in cloud point per unit addition of the hydrotropic agent. Thus, the hydrotropic agent with structure (I) successfully transforms a 1 wt% non - ionic surfactant solution with an initial cloud point of 35 °C in an aqueous solution at 23 °C from turbid (i.e., insoluble) to clear, where with the addition of only 2.5 wt% of the hydrotropic agent, the cloud point of the formulation increases to 54 °C - 57 °C. When the dosage of the hydrotropic agent is 5.0 wt%, the cloud point of the formulation of IE1 is higher than 85 °C. It can be seen that although CE1 (having a glucose repeat unit value of 1.4) effectively dissolves SURF by increasing the cloud point of the formulation to 46 °C - 47.5 °C at a dosage of 2.5 wt% and to 69 °C - 71 °C at a dosage of 5.0 wt%, CE2 (having an m value of 2.35 in structure (I)) fails to dissolve SURF. During the CE2 test, adding SURF to the NaOH and hydrotropic agent solution makes the solution turbid, and phase separation occurs within 4 hours.

[0064] Table 4

[0065]

[0066] Now referring to Table 4, IE1 is capable of achieving a desired target of an initial foam height of 10 mm or less and a foam height of 0 mm after 5 minutes. Different from IE1, CE1 and CE2 exhibit initial foam heights of 25 mm and 18 mm, respectively. Residual foams of CE1 and CE2 also exist. As demonstrated in Tables 3 and 4, the hydrotropes having Structure (I) can effectively couple SURF to the alkaline cleaning composition, producing an initial foam height of 10 mm or less and a foam height of less than 0 mm after 5 minutes according to the Ross-Miles foam test.

[0067] Table 5

[0068] Time (seconds) IE1 CE1 CE2 0 5.0 5.0 5.4 15 19.0 33.0 23.0 30 17.5 47.5 31.2 60 14.5 55.0 30.6 75 4.3 54.0 19.0 90 4.3 52.1 8.5 120 4.3 47.6 7.6 180 4.3 19.0 7.6 240 4.3 15.7 7.6 300 4.3 15.0 7.6

[0069] Now referring to Table 5, it is self-evident that IE1 performs better than CE1 and CE2 in terms of preventing foam generation during the test and at the same time dissipating the foam more quickly.

Claims

1. A cleaning composition, the cleaning composition comprising: Water; A surfactant; and A hydrotrope having structure (I) Wherein according to 13 13C nuclear magnetic resonance measurements, m of structure (I) is from 1.0 to 1.

2.

2. The coating composition according to claim 1, wherein the surfactant is a nonionic surfactant.

3. The cleaning composition according to one of claims 1 and 2, wherein the cleaning composition comprises 0.01 wt% to 10.0 wt% of the surfactant based on the total weight of the cleaning composition.

4. The cleaning composition according to one of claims 1 to 3, wherein the cleaning composition comprises an alkali metal salt.

5. The cleaning composition according to one of claims 1 to 4, wherein the cleaning composition comprises 0.1 wt% or more of NaOH based on the total weight of the cleaning composition.

6. The cleaning composition according to one of claims 1 to 5, wherein the cleaning composition comprises 0.01 wt% to 20.0 wt% of the hydrotrope.

7. The cleaning composition according to claim 6, wherein the cleaning composition comprises 0.5 wt% to 10.0 wt% of the hydrotrope based on the total weight of the cleaning composition.

8. The cleaning composition according to any one of claims 1 to 7, wherein m of structure (I) is 1.0.

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