EP4630524A1

EP4630524A1 - Hydrotrope cleaning compositions

Info

Publication number: EP4630524A1
Application number: EP22839999.4A
Authority: EP
Inventors: Cheng Shen; Tao Wang; Chen Zheng; Xiaolin Ma; Dan Jiang; Jieying Chen
Original assignee: Dow Global Technologies LLC
Current assignee: Dow Global Technologies LLC
Priority date: 2022-12-05
Filing date: 2022-12-05
Publication date: 2025-10-15
Also published as: JP2026500610A; CN120153053A; WO2024119291A1

Abstract

A cleaning composition including water, a surfactant and a hydrotrope having Structure (I), wherein m of Structure (I) is from 1.0 to 1.2 as measured according to ¹³C Nuclear Magnetic Resonance.

Description

HYDROTROPE CLEANING COMPOSITIONS

BACKGROUND

Field of the disclosure
The present disclosure is related to cleaning compositions and more specifically to cleaning compositions that comprise a hydrotrope.
Introduction
In cleaning applications, hydrotropes are compounds which enable the solubilization of surfactants into a formulation at a higher concentration than the formulation would typically support. Hydrotropes are useful materials because under certain circumstances, such as high alkalinity (i.e., 10 weight percent ( “wt%” ) of NaOH in the cleaning formulation or even higher) the solubility of a surfactant in a cleaning composition is low. The low solubility of the surfactant in the cleaning composition means that not only may the cleaning composition not have sufficient detergency due to low surfactant loading, but also may exhibit a hazy appearance (due to insolubility of the surfactant in the formulation) , phase separation and instability. As such, hydrotropes can be thought of as a coupling or solubilization agent between the surfactant and cleaning composition. A measurement for how well a hydrotrope couples a non-ionic surfactant (the type of surfactant most common in industrial cleaning formulations) to an alkaline composition is the amount of hydrotrope required to impart a cloud point increase to the cleaning composition. A hydrotrope would be considered successful in coupling if a 1 wt%nonionic surfactant solution having an initial cloud point at 35℃ in a 5 wt%NaOH water solution at 23℃is transformed from hazy (i.e., not soluble) to clear with just the addition of 2.5 wt%the hydrotrope.
Hydrotropes may also affect other properties of the cleaning composition. For example, some hydrotropes are known to produce stable foams which are typically not advantageous in industrial cleaning settings. For example, some alkyl polyglucosides can be used for hydrotropes, but as United States Patent No 3,219,656 explains that alkyl polyglucosides “show high stable foams and which act as foam stabilizers for other surfactants. ” Stable foams in industrial cleaning applications present problems due to additional rinsing time and water consumption as well as the foam interfering with the machinery of the cleaning system. The Ross-Miles Foam Height test is a standard foam test method for amphiphilic materials where a water solution of surfactant or hydrotrope sample is poured into the test tube and its initial height of any foam is compared against the height of the foam after 5 minutes of allowing the foam to dissipate. Typically, a surfactant or hydrotrope exhibiting an initial foam height (at 0.1 wt%aqueous solution) less than 50 mm and a foam height less than 20 mm after 5 minutes are considered to be low foam surfactant or hydrotrope.
An additional, and increasingly important trend is the switch to environment-friendly hydrotropes. It is an increasing consideration of cleaning solution manufacturers is that components utilized in the cleaning solution be eco-friendly and biodegradable. Traditional hydrotropes include phosphate type and (di) sulfonate type, both of which are coming under increasing scrutiny. For example, phosphorus containing hydrotropes are alleged to result in increased eutrophication of water ways while some of sulfonate type hydrotropes are not readily biodegradable, or strong eye/skin irritation.
In view of these competing interests, it would be surprising to discover a cleaning composition utilizing an alkyl polyglucoside hydrotrope that not only is successful under the guidelines laid out above, but also exhibits less than 50 mm of initial foam and less than 20 mm of foam after 5 minutes when tested at 0.1 wt%according to the Ross-Miles Foam Height Test and is readily biodegradable.
SUMMARY OF THE DISCLOSURE
The inventors of the present application have discovered a cleaning composition utilizing an alkyl polyglucoside hydrotrope that not only is successful under the guidelines laid out above, but also exhibits less than 50 mm of initial foam and less than 20 mm of foam after 5 minutes when tested at 0.1 wt%according to the Ross-Miles Foam Height Test and is readily biodegradable.
The present disclosure is a result of discovering that cleaning compositions can achieve the above-noted benefits when utilizing a hydrotrope having Structure (I)
wherein m is from 1.0 to 1.2. As explained above, alkyl glucosides are typically used in applications where high and stable foam is desired. Surprisingly, the branched alkyl 2-octanol in Structure (I) with an m from 1.0-1.2 exhibits 10 mm of initial foam and 0 mm of foam after 5 minutes when tested at 0.1 wt%according to the Ross-Miles Foam Height Test. Without being bound by theory, it is believed that the lightly branched nature of Structure (I) renders the hydrotrope unable to stabilize foams generated by agitation of cleaning compositions including the hydrotrope. The low m value in combination with the 2-octyl of Structure (I) is also believed to place the hydrophilic-lipophilic balance of the hydrotrope at a value which provides superior cloud point increase rending the hydrotrope a successful in solubilizing and coupling the surfactant to the cleaning composition. Finally, the use of the alkyl glucoside hydrotrope does not negatively impact the biodegradability and eco-friendly nature of cleaning compositions it is added to as compared to phosphate or sulfonate hydrotropes.
According to a first feature of the present disclosure, a cleaning composition comprises water, a surfactant and a hydrotrope having Structure (I) wherein m of Structure (I) is from 1.0 to 1.2 as measured according to ¹³C Nuclear Magnetic Resonance.
According to a second feature of the present disclosure, the surfactant is a non-ionic surfactant.
According to a third feature of the present disclosure, the cleaning composition comprises from 0.01 wt%to 10.0 wt%of the surfactant based on a total weight of the cleaning composition.
According to a fourth feature of the present disclosure, the cleaning composition comprises an alkali salt.
According to a fifth feature of the present disclosure, the cleaning composition comprises 0.1 wt%of NaOH or greater based on a total weight of the cleaning composition.
According to a sixth feature of the present disclosure, the cleaning composition comprises from 0.01 wt%to 20.0 wt%of the hydrotrope.
According to a seventh feature of the present disclosure, the cleaning composition comprises from 0.5 wt%to 10.0 wt%of the hydrotrope based on a total weight of the cleaning composition.
According to an eighth feature of the present disclosure, wherein m of Structure (I) is 1.0.

DETAILED DESCRIPTION

As used herein, the term “and/or, ” when used in a list of two or more items, means that any one of the listed items can be employed by itself, or any combination of two or more of the listed items can be employed. 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.
All ranges include endpoints unless otherwise stated.
As used herein, the term weight percent ( “wt%” ) designates the percentage by weight a component is of a total weight of the glycol composition unless otherwise specified.
As used herein, Chemical Abstract Services registration numbers ( “CAS#” ) refer to the unique numeric identifier as most recently assigned as of the priority date of this document to a chemical compound by the Chemical Abstracts Service.
Cleaning composition
The cleaning composition of the present disclosure comprises water, a surfactant, and a hydrotrope having Structure (I) :
wherein m of Structure (I) is from 1.0 to 1.2 as measured according to ¹³C Nuclear Magnetic Resonance. The cleaning composition comprises from 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 greater, or 72 wt%or greater, or 74 wt%or greater, or 76 wt%or greater, or 78 wt%or greater, or 80 wt%or greater, or 82 wt%or greater, or 84 wt%or greater, or 86 wt%or greater, or 88 wt%or greater, or 90 wt%or greater, or 92 wt%or greater, or 94 wt%or greater, or 96 wt%or greater, or 98 wt%or greater, 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 based on the total weight of the cleaning composition.
Surfactant
The cleaning composition comprises a surfactant. As used herein, the term “surfactant” means a material that is capable of lowering the interfacial energy between two dissimilar substances. The surfactant may be an anionic surfactant, a non-ionic surfactant, a cationic surfactant, an amphoteric surfactant and/or combinations thereof. The hydrophobic portion of the surfactant may be branched or linear, primary alkyl or secondary alkyl, saturated or unsaturated, or (multi) -aryl-containing alkyl. In a specific example, the surfactant may be a branched alcohol ethoxylate. A commercially available example of the surfactant may include ECOSURF ^TM LFE-635 from The Dow Chemical Company, Midland, MI; or a broadly commercially available example of primary C12-14 alcohol ethoxylate, such as TERGITOL ^TM 26-L-9.
The cleaning composition may comprise from 0.01 wt%to 10.0 wt%of the surfactant based on a total weight of the cleaning composition. For example, the cleaning composition may comprise 0.01 wt%or greater, or 0.1 wt%or greater, or 0.5 wt%or greater, or 1.0 wt%or greater, or 1.5 wt%or greater, or 2.0 wt%or greater, or 2.5 wt%or greater, or 3.0 wt%or greater, or 3.5 wt%or greater, or 4.0 wt%or greater, or 4.5 wt%or greater, or 5.0 wt%or greater, or 5.5 wt%or greater, or 6.0 wt%or greater, or 6.5 wt%or greater, or 7.0 wt%or greater, or 7.5 wt%or greater, or 8.0 wt%or greater, or 8.5 wt%or greater, or 9.0 wt%or greater, or 9.5 wt%or greater, 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 the surfactant based on the total weight of the cleaning composition.
Hydrotrope
The cleaning composition comprises the hydrotrope having Structure (I) :
wherein m of Structure (I) is from 1.0 to 1.2 as measured according to ¹³C Nuclear Magnetic Resonance. For example, 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 as measured according to ¹³C Nuclear Magnetic Resonance. The m moiety of Structure (I) may also be referred to as glucose repeating unit.
The cleaning composition may comprise from 0.01 wt%to 20.0 wt%of the hydrotrope based on a total weight of the cleaning composition. For example, the cleaning composition may comprise 0.01 wt%or greater, or 0.1 wt%or greater, or 0.5 wt%or greater, or 1.0 wt%or greater, or 1.5 wt%or greater, or 2.0 wt%or greater, or 2.5 wt%or greater, or 3.0 wt%or greater, or 3.5 wt%or greater, or 4.0 wt%or greater, or 4.5 wt%or greater, or 5.0 wt%or greater, or 5.5 wt%or greater, or 6.0 wt%or greater, or 6.5 wt%or greater, or 7.0 wt%or greater, or 7.5 wt%or greater, or 8.0 wt%or greater, or 8.5 wt%or greater, or 9.0 wt%or greater, or 9.5 wt%or greater, 10.0 wt%or greater, or 10.5 wt%or greater, or 11.0 wt%or greater, or 11.5 wt%or greater, or 12.0 wt%or greater, or 12.5 wt%or greater, or 13.0 wt%or greater, or 13.5 wt%or greater, or 14.0 wt%or greater, or 14.5 wt%or greater, or 15.0 wt%or greater, or 15.5 wt%or greater, or 16.0 wt%or greater, or 16.5 wt%or greater, or 17.0 wt%or greater, or 17.5 wt%or greater, or 18.0 wt%or greater, or 18.5 wt%or greater, or 19.0 wt%or greater, or 19.5 wt%or greater, 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 the hydrotrope based on the total weight of the cleaning composition.
Alkali Salt
The cleaning composition may comprise an alkali salt. For example, the alkali salt may be an alkaline or alkaline earth hydroxide. The alkali salt may be selected from the group consisting of sodium hydroxide (i.e., NaOH) , potassium hydroxide, and/or combinations thereof or with certain amine, such as monoethaonlamine.
The cleaning composition may comprise from 0.01 wt. %to 40.00 wt. %of the alkali salt based on a total weight of the cleaning mixture. For example, the cleaning mixture may comprise 0.01 wt. %or greater, or 0.1 wt. %or greater, or 0.50 wt. %or greater, or 1.00 wt. %or greater, or 1.50 wt. %or greater, or 2.00 wt. %or greater, or 2.50 wt. %or greater, or 5.00 wt. %or greater, or 7.50 wt. %or greater, or 10.00 wt. %or greater, or 12.50 wt. %or greater, or 15.00 wt. %or greater, or 17.50 wt. %or greater, or 20.00 wt. %or greater, or 22.50 wt. %or greater, or 25.00 wt.%or greater, or 27.50 wt. %or greater, or 30.00 wt. %or greater, or 32.50 wt. %or greater, or 35.00 wt. %or greater, or 37.50 wt. %or greater, 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 the alkali salt based on the total weight of the cleaning composition.
Additives
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 greater, or 1 wt%or greater, or 2 wt%or greater, or 3 wt%or greater, or 4 wt%or greater, or 5 wt%or greater, or 6 wt%or greater, or 7 wt%or greater, or 8 wt%or greater, or 9 wt%or greater, or 10 wt%or greater, or 11 wt%or greater, or 12 wt%or greater, or 13 wt%or greater, or 14 wt%or greater, or 15 wt%or greater, or 16 wt%or greater, or 17 wt%or greater, or 18 wt%or greater, or 19 wt%or greater, 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 based on the total weight of the cleaning composition. The additives may include one or more diluents such as propylene glycol and/or other diluents. The additives may include one or more defoaming agents 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 ( “EDTA” ) acid, citric acid, potassium citrate, sodium citrate, tetrasodium ethylene-diaminetetraacetate, tetrasodium ethylene-diaminetetraacetate, tetrasodium ethylene-diaminetetraacetate, diammonium ethylene-diaminetetraacetate, tetrasodium ethylene-diaminetetraacetate, tetrasodium ethylene-diaminetetraacetate tetrahydrate, disodium ethylene-diaminetetraacetate tetrahydrate, ethylenediaminetetraacetic acid, disodium ethylene-diaminetetraacetate dihydrate, calcium disodium ethylene-diaminetetraacetate dihydrate, pentasodium diethylenetriaminepentaacetate, pentasodium diethylene-triaminepentaacetate, trisodium n- (hydroxyethyl) -ethylenediaminetriacetate, iron disodium n- (hydroxyethyl) -ethylenediaminetriacetate, ethylenediaminetetraacetic acid and combinations thereof.
Examples
Materials
The below noted materials were used in formation of the inventive examples ( “IE” ) and the comparative examples ( “CE” ) .
2OG is 2-octyl glucoside having Structure (I) with an m value of 1.0. The 2OG was formed by performing the following steps. First, 2-octanol (36.7 g, 0.282 mol, 1.1 eq. ) and D-glucose penta-acetate (100 g, 0.256 mol, 1 eq. ) were dissolved in 300 mL of dichloromethane (DCM) at 23℃ to form a solution. Next, boron trifluoride etherate (40 g, 0.282 mol, 1.1 eq. ) was then added in a dropwise manner over the course of 3 minutes to the solution. The solution was magnetically stirred for 48 hours at 23℃. Next, a 150 ml of saturated sodium bicarbonate solution was added into the solution and the resulting biphasic mixture was shaken until effervescence was no more observed. The biphasic mixture was then transferred into an extraction funnel for separation. Next, the organic phase was collected and the aqueous phase was washed by 100 mL of DCM. The separated organic phase was mixed with the previous organic phase. Next, 60g of sodium sulfate powder was then added into the combined organic phases to remove the residual water. The resulting organic phase was magnetically stirred for 30 minutes. Next, the solid that formed was filtrated, and the organic solvent (DCM) was removed from the dried organic phase under reduced pressure around 20 KPa at 23℃ to give a yellow oily crude product. The crude product was dissolved in mixture solvent (petroleum ether /ethyl acetate 10: 1) and purified by silica gel column (petroleum ether /ethyl acetate 10: 1 by vol. ) to remove the impurity. And then the mixed solvent was distillated out by rotary evaporator under 20 KPa at 30℃ to give a yellow solid product (18 g) . The yellow solid product then underwent a de-acetylation process. 10 grams of the yellow solid product was dissolved in 100 mL of methanol. Next, 30 g of anion-exchange resin Amberlite 400 (OH) was added at 23℃ in one portion to form a slurry. The slurry was kept magnetic stirring at 23℃ overnight. After stirring, all the solids were collected by filtration, then was rinsed with methanol. The methanol was removed by rotary evaporation under 20 KPa at 35℃ to get the 2-octyl glucoside of Structure (I) .
APG is isooctyl Glucoside having a CAS#of 125590-73-0 and a has Structure (II)
wherein n is 1.4 (i.e., the repeating glucose unit) . APG is commercially available as GREENAPG ^TM IC-08 from Shanghai Fine Chemical Co., Ltd., Shanghai, CHINA.
SURF is a non-ionic branched alcohol alkoxylate surfactant having a cloud point of 35℃and is commercially available as ECOSURF ^TM LFE-635 from The Dow Chemical Company, Midland, MI.
PG is a 2-octyl polyglucoside having Structure (I) with an m value from greater than 1.5. The PG was formed by performing the following steps. First, 2-octanol (65.1 g, 0.5 mol, 5 eq. ) and D-glucose (18.0 g, 0.1 mol, 1 eq. ) were added to a 100 mL flask. Para-toluene sulfonic acid (0.344 g, 0.002 mol, 0.02 eq. ) was then added in the flask, and the mixture was heated to 110℃ in an oil bath with magnetic stirring. A vacuum was slowly applied to the flask and kept at 50 kPa to 70 kPa to remove the water generated during the reaction and was adjusted to avoid the evaporation of 2-octanol. The reaction was run for 6 hours. After completion of the reaction, the pH was adjusted to 7-8 with 2 mol/L NaOH aqueous solution after stopping the vacuum and cooling down to 23℃. Then, the excess 2-octanol was removed (< 1 KPa) at 90℃. A yellow or brown wax-like solid was obtained as final product. The 2-octyl polyglucoside had an m value in Structure (I) of 2.35 as measured according to ¹³C Nuclear Magnetic Resonance.
NaOH is an aqueous solution of 80 g of sodium hydroxide per liter of water.
Sample Preparation and Test Methods
Hydrotrope Performance Test: A water solution of hydrotrope was prepared first at 50 wt.%active concentration. Based on the total amount of each ingredient in the final testing solution (10 mL) : 0.5 g NaOH solid was added into 8.9 g water or 8.4 g water; after its full dissolution, then 0.5 g or 1.0 g hydrotrope water solution (50 wt. %) was added into the 5 wt. %NaOH aq. soln., which targeted to a 2.5 wt. %active or 5 wt. %active concentration of hydrotrope in the final testing solution. Once it was well mixed, 0.1 g SURF was added into the mixture at an active concentration at 1 wt. %. The test tube was put into a hot water bath. When the appearance of the testing solution turned hazy, the tube was taken out, then we recorded the temperature where the solution turned from hazy to clear as its cloud point. And, such an operation was repeated three times to get an average cloud point.
Ross-Miles Foam Test: The test was conducted in accordance with China national standard GB/T 13173-2008 foaming test. A 0.1 wt. %active aqueous solution of hydrotrope was prepared with deionized water. The Ross-Miles test tube was rinsed with deionized water, and previously prepared sample solution (0.1 wt%active aqueous solution) . 50 mL of the sample solution was poured into the test tube. Once no foaming was observed for this first 50 mL of sample solution, 200 mL of sample solution was added via a dropping pipette. The tap of dropping pipette was then opened for the solution to flow down into the test tube. Once the flow of the solution was over, the initial foam height was recorded as the initial height. At the end of 5 min, the foam height was recorded as the final one.
Circulating Bubble Foam test: A special circulating foaming machine was used. The whole test was carried out at 23℃. About 250 mL of surfactant (0.1%by weight active SURF) aqueous solution was prepared in a beaker. The solution was kept stirring until the SURF was completely dissolved in water, and then it was poured into the glass test bottle. This pouring operation might cause some foam, and the machine was started after the bubbles disappeared. The initial volume reading was 5 mL, representing the volume of the original liquid (the total volume of the foam and liquid was recorded in the test; due to the liquid remaining on the wall in the end of the test, the final volume reading was likely less than 5 mL) . The total test lasted 5 minutes: the machine was on in the first minute and the total volume readings at 15, 30 and 60 seconds were recorded. After turning off the machine for 60 seconds, the total volumes at 75, 90 seconds, 2, 3, 4 and 5 minutes were recorded, respectively.
¹³C Nuclear Magnetic Resonance: A sample (～0.3 g) was dissolved in D ₂O (0.8 mL) at 23℃ to get a homogenous solution. The resultant solution was added into 5 mm tube and sent for NMR analysis. All NMR data were acquired at 23℃ on a Bruker AVANCE ^TM II 400 MHz spectrometer operating at a ¹³C resonance frequency of 100.6 MHz. A 5 mm BBO probe was employed. Zgig was used as the pulse program of ¹³C NMR with an observe pulse of 90 degrees. Recycle delay was set to 14 seconds. The sample was scanned 4000 times. The glucose unit number (PD) was calculated by the integral of corresponding peaks in ¹³C NMR spectrum using Equations 1-3.
Reacted Glucose= total glucose (CH ₂ signal in 65-59 ppm) -free glucose (CH, 95.9 ppm, 92.1 ppm) Eq. (1)
Reacted 2-octanol= total 2-octanol (CH ₃, 13.6 ppm) –free 2-octanol (CH2, 38.8 ppm) Eq. (2)
PD= reacted Glucose /reacted 2-octanol Eq. (3)
Results
Table 3 provides the results of the hydrotrope performance test in the 5 wt%NaOH alkaline environment, Table 4 provides the results of the Ross-Miles foam test, and Table 5 provides the results of the circulating foam test at 0.5 wt. %active content.
Table 3
*: hazy appearance at 23℃.
Referring now to Table 3, the blank example demonstrates that the SURF (at 1 wt. %) is insoluble in the 5%wt. NaOH water solution without the hydrotrope present. IE1 demonstrates that use of the hydrotrope having Structure (I) (having a glucose repeat unit value of 1.0) provides the greatest increase in cloud point per unit addition of hydrotrope relative to CE1 and CE2. As such, the hydrotrope having Structure (I) is successful in transforming a 1 wt. %nonionic surfactant solution having an initial cloud point at 35℃ in a water solution at 23℃ is from hazy (i.e., not soluble) to clear with the cloud point of the formulation increasing to 54-57℃ with just the addition of 2.5 wt. %the hydrotrope. When the hydrotrope dosage was at 5.0 wt. %, the cloud point of the formulation with IE1 was higher than 85℃. It can be seen that while CE1 (having a glucose repeat unit value of 1.4) is effective in solubilizing the SURF by increasing the cloud point of the formulation to 46-47.5℃ with the dosage at 2.5 wt. %and 69-71℃ with the dosage at 5.0 wt. %, CE2 (having an m value of 2.35 in Structure (I) ) is unable to solubilize the SURF. During testing of CE2, the addition of the SURF to the NaOH and hydrotrope solution caused the solution to turn hazy and phase separation occurred within 4 hours.
Table 4
Referring now to Table 4, IE1 is able to achieve the desired target of having an initial foam height of 10 mm or less and 0 mm of foam after 5 minutes. Unlike IE1, CE1 and CE2 exhibit an initial foam height of 25 mm and 18 mm, respectively. Residual foam for CE1 and CE2 also exist. As demonstrated by Tables 3 and 4, the hydrotrope of Structure (I) is able to effectively couple the SURF to the alkaline cleaning compositions, produce an initial foam height of 10 mm or less and a foam height less than 0 mm after 5 minutes according to Ross-Miles Foam Testing.
Table 5
Referring now to Table 5, it is self-evident that IE1 performs better at both preventing foam production during the test while also causing the foam to dissipate quicker as compared to CE1 and CE2.

Claims

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 as measured according to ¹³C Nuclear Magnetic Resonance.
The cleaning composition of claim 1, wherein the surfactant is a non-ionic surfactant.
The cleaning composition of one of claims 1 and 2, wherein the cleaning composition comprises from 0.01 wt%to 10.0 wt%of the surfactant based on a total weight of the cleaning composition.
The cleaning composition of one of claims 1-3, wherein the cleaning composition comprises an alkali salt.
The cleaning composition of one of claims 1-4, wherein the cleaning composition comprises 0.1 wt%of NaOH or greater based on a total weight of the cleaning composition.
The cleaning composition of one of claims 1-5, wherein the cleaning composition comprises from 0.01 wt%to 20.0 wt%of the hydrotrope.
The cleaning composition of claim 6, wherein the cleaning composition comprises from 0.5 wt%to 10.0 wt%of the hydrotrope based on a total weight of the cleaning composition.
The cleaning composition of any one of claims 1-7, wherein m of Structure (I) is 1.0.