Hydrotropes for alkaline compositions containing nonionic surfactants and cleaning compositions containing the same

Abstract

To provide a hydrotrope agent capable of improving the solubility of a nonionic surfactant in an alkaline aqueous solution (alkaline composition).SOLUTION: The hydrotrope agent for an alkaline composition containing a nonionic surfactant comprises a compound represented by formula (1). In Formula (1), R1 represents a saturated or unsaturated hydrocarbyl group having 1 to 10 carbon atoms, A1 and A2 each independently represent a linear or branched alkylene group having 2 to 4 carbon atoms, n and m each independently represent an average number of added moles of oxyalkylene groups represented by A1O and A2O and each independently represent a number of 1 to 6, and n + m = 2 to 10.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a hydrotropic agent for alkaline compositions containing nonionic surfactants and to alkaline compositions containing the same. [Background technology]

[0002] Hydrotropes are substances used to dissolve compounds that are poorly soluble or insoluble in water in an aqueous phase. The solubility of such compounds with low solubility in water is further reduced not only by their chemical structure but also by the presence of salts (e.g., alkaline compounds) in the aqueous phase. Hydrotropes are particularly used in cosmetic compositions, pharmaceutical compositions, and cleaning compositions for household or industrial use.

[0003] For example, Patent Document 1 discloses, as a hydrotropic agent, a secondary alcohol alkoxylate in which a secondary alcohol having 3 to 22 carbon atoms is alkoxylated with oxyalkylene units selected from oxyethylene (OE), oxypropylene (OP), and oxybutylene (OB), and the total number of oxyalkylene units is 2 to 100. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2022-552998 Summary of the Invention [Problem to be solved by the invention]

[0005] Even when the hydrotrope agent described in Patent Document 1 was used, it was difficult to incorporate a nonionic surfactant into an alkaline aqueous solution (alkaline composition) containing an alkaline compound at a high concentration (for example, a sodium hydroxide concentration of 8% by mass or more). Therefore, even with the hydrotrope agents proposed by the prior art, there is still room for improvement in terms of improving the solubility of nonionic surfactants in alkaline aqueous solutions (alkaline compositions).

[0006] Therefore, an object of the present invention is to provide a means for improving the solubility of a nonionic surfactant in an alkaline aqueous solution (alkaline composition). [Means for solving the problem]

[0007] The present inventors have conducted extensive research to solve the above problems, and as a result have found that the above problems can be solved by using a hydrotropic agent having a specific structure, which has led to the completion of the present invention.

[0008] That is, according to one embodiment of the present invention, a compound represented by the following formula (1):

[0009] [ka]

[0010] In formula (1), R 1 represents a saturated or unsaturated hydrocarbon group having 1 to 10 carbon atoms, A 1 and A 2 each independently represents a linear or branched alkylene group having 2 to 4 carbon atoms, n and m are A 1 O and A 2 represents the average number of moles of oxyalkylene groups added, each independently being a number of 1 to 6, and n+m=2 to 10; The present invention provides a hydrotropic agent for a nonionic surfactant-containing alkaline composition, comprising a compound represented by the formula: [Effects of the Invention]

[0011] The hydrotrope according to the present invention can improve the solubility of a nonionic surfactant in an alkaline aqueous solution (alkaline composition). DETAILED DESCRIPTION OF THE INVENTION

[0012] The following describes in detail the embodiments of the present invention. The embodiments described herein are merely illustrative examples for embodying the technical concept of the present invention and are not intended to limit the present invention. Therefore, all other possible embodiments, methods of use, and operational techniques conceivable by those skilled in the art without departing from the spirit of the present invention are within the scope and spirit of the present invention, as well as within the scope of the claims and their equivalents. The embodiments described herein can be arbitrarily combined to produce other embodiments. Furthermore, in this specification, the term "X to Y" indicating a range means "X or more and Y or less," and "weight," "weight %," "mass %," and "parts by weight" and "parts by mass" are treated as synonyms. Unless otherwise specified, operations and measurements of physical properties are performed at room temperature (20-25°C) and a relative humidity of 40-60%.

[0013] <Hydrotrope> One aspect of the present invention provides a hydrotropic agent for a nonionic surfactant-containing alkaline composition, which comprises a compound represented by the following formula (1):

[0014] [ka]

[0015] In formula (1), R 1 represents a saturated or unsaturated hydrocarbon group having 1 to 10 carbon atoms, A 1 and A 2 each independently represents a linear or branched alkylene group having 2 to 4 carbon atoms, n and m are A 1 O and A 2 O, and are independently a number of 1 to 6, and n+m=2 to 10.

[0016] According to the inventors' investigations, it has been found that the hydrotrope according to the present embodiment has the effect of improving the solubility of a nonionic surfactant contained in an alkaline composition. Therefore, the hydrotrope according to the present embodiment is added to an alkaline composition to improve the solubility of the nonionic surfactant. For example, the hydrotrope improves the solubility of a nonionic surfactant contained in an alkaline composition. More specifically, the hydrotrope improves the solubility of a nonionic surfactant in an alkaline composition containing a high concentration (e.g., 8% by mass or more) of an alkaline compound. Alkaline compositions containing a high concentration of an alkaline compound tend to reduce the solubility of nonionic surfactants and lower the cloud point due to their high electrolyte concentration. The hydrotrope according to the present embodiment can improve the cloud point of an alkaline composition containing a nonionic surfactant. Here, the cloud point is the temperature at which one or more components contained in the composition (solution) become insoluble (not solubilized) in the composition (solution), and the cloud point can be used to determine the temperature at which the composition (solution) becomes unstable. The higher the cloud point, the more stable the composition (solution), and the lower the cloud point, the less stable the composition (solution).

[0017] According to one embodiment, the hydrotrope agent of this embodiment suppresses the cloud point phenomenon of nonionic surfactants. According to one embodiment, the hydrotrope agent of this embodiment improves the cloud point. This allows an alkaline composition to contain a high concentration of electrolytes (e.g., a high concentration of alkaline compounds) while also containing a high concentration of nonionic surfactants. Therefore, the hydrotrope agent of this embodiment is added to an alkaline composition to suppress the cloud point phenomenon of nonionic surfactants.

[0018] The reason why the hydrotrope agent of this embodiment exhibits the above-mentioned effects is unclear, but it is thought to be as follows. Because the compound represented by formula (1) is a tertiary amine compound, it can better suppress the dissociation of electrolytes such as alkaline compounds (e.g., sodium ions in sodium hydroxide) compared to primary and secondary amine compounds. It is also speculated that in alkaline compositions containing alkaline compounds, the balance between the hydrophobicity (hydrocarbon group) and hydrophilicity (amino group, oxyalkylene group, and terminal hydroxyl group) of the compound represented by formula (1) acts favorably, protecting the hydrogen bond between the polyether chain (oxyalkylene group) and water in nonionic surfactants. In other words, it is believed that the compound represented by formula (1) acts as an excellent amphiphilic solubilizer for alkaline compounds (e.g., sodium hydroxide) and nonionic surfactants, enabling high-concentration dissolution of both. It should be noted that the present invention is in no way limited to the above mechanism.

[0019] The hydrotrope agent according to this embodiment has the above-mentioned effect, thereby enabling a high pH to be established in an alkaline composition (allowing for a highly concentrated alkaline aqueous solution). Therefore, for example, a cleaning composition containing the hydrotrope agent according to this embodiment can achieve high detergency. Furthermore, since the hydrotrope agent according to this embodiment itself is alkaline, a cleaning composition containing the hydrotrope agent according to this embodiment does not experience a decrease in the alkalinity of the cleaning composition, and thus does not experience a decrease in cleaning performance. Because the hydrotrope agent according to this embodiment is amphiphilic, it can function as a detergent component and contribute to improved detergency. The hydrotrope agent according to this embodiment can effectively dissolve electrolytes and nonionic surfactants, even when the water content is high.

[0020] The compound represented by the following formula (1) contained in the hydrotropic agent according to this embodiment will be described below.

[0021] [ka]

[0022] In formula (1), R 1 represents a saturated or unsaturated monovalent hydrocarbon group having 1 to 10 carbon atoms. Here, the saturated or unsaturated hydrocarbon group may be linear, branched, or cyclic. Examples of the saturated or unsaturated hydrocarbon group include an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, a cycloalkenyl group, a cycloalkynyl group, and an aryl group.

[0023] R in the above formula (1) 1 Examples of the alkyl group represented by the formula (I) include alkyl groups having 1 to 10 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a sec-pentyl group, a 3-pentyl group, a tert-pentyl group, a neopentyl group, a 1,2-dimethylpropyl group, an n-hexyl group, a cyclohexyl group, a 1,3-dimethylbutyl group, a 1-isopropylpropyl group, a 1,2-dimethylbutyl group, an n-heptyl group, a 1,4-dimethylpentyl group, a 2-methyl-1-isopropylpropyl group, a 1-ethyl-3-methylbutyl group, an n-octyl group, a 2-ethylhexyl group, and a decyl group.

[0024] R in the above formula (1) 1 Examples of the alkenyl group represented by the formula (I) include alkenyl groups having 2 to 10 carbon atoms, such as a vinyl group (ethenyl group), an allyl group (2-propenyl group), an isopropenyl group, a 1-butenyl group, a 3-butenyl group, a 1-pentenyl group, an isopentenyl group, a 1-hexenyl group, a 5-hexenyl group, and a 2-octenyl group.

[0025] R in the above formula (1) 1Examples of the alkynyl group represented by the formula (I) include alkynyl groups having 2 to 10 carbon atoms, such as an ethynyl group, a 1-propynyl group, a 2-propynyl group, a 1-butynyl group, a 2-butynyl group, a 3-butynyl group, a 3-methyl-1-propynyl group, a 2-methyl-3-propynyl group, a pentynyl group, a 1-hexynyl group, a 3-methyl-1-butynyl group, and a 3,3-dimethyl-1-butynyl group.

[0026] R in the above formula (1) 1 Examples of the cycloalkyl group represented by the formula (1) include cycloalkyl groups having 3 to 10 carbon atoms, such as a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group, and an adamantyl group. 1 Examples of the cycloalkenyl group represented by the formula (1) include cycloalkenyl groups having 4 to 10 carbon atoms, such as a cyclobutenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a cyclooctenyl group, and a cyclodecenyl group. 1 Examples of the cycloalkynyl group represented by the formula: include cycloalkynyl groups having 4 to 10 carbon atoms such as a cyclobutynyl group, a cyclopentynyl group, a cyclohexynyl group, a cycloheptynyl group, a cyclooctynyl group, and a cyclodecynyl group.

[0027] R in the above formula (1) 1 Examples of the aryl group represented by the formula: include aryl groups having 6 to 10 carbon atoms, such as a phenyl group, a methylphenyl group, and a dimethylphenyl group.

[0028] Among these, from the viewpoint of solubility of nonionic surfactants, R 1 is preferably an alkyl group having 1 to 8 carbon atoms, more preferably an alkyl group having 2 to 6 carbon atoms, even more preferably an alkyl group having 2 to 5 carbon atoms, particularly preferably an alkyl group having 2 to 4 carbon atoms, and most preferably an alkyl group having 3 or 4 carbon atoms. 1 is a butyl group.

[0029] In formula (1), A 1 and A2 Each independently represents a linear or branched alkylene group having 2 to 4 carbon atoms. Examples of the linear or branched alkylene group having 2 to 4 carbon atoms include an ethylene group (-CH2CH2-), a methylmethylene group (-CH2(CH3)-), a trimethylene group (-CH2CH2CH2-), a 2-methylethylene group (-CH2-CH(CH3)-), a tetramethylene group (-CH2CH2CH2CH2-), a 1-methyltrimethylene group (-CH(CH3)CH2CH2-), a 2-methyltrimethylene group (-CH2CH(CH3)CH2-), a 1,1-dimethyldimethylene group (-C(CH3)(CH3)CH2-), and a 1,2-dimethyldimethylene group (-CH(CH3)CH(CH3)-). These alkylene groups, together with an oxygen atom, form an oxyalkylene group. This oxyalkylene group (A 1 O groups and A 2 O groups) may be the same or a mixture of different types (block or random), and preferably are oxyethylene groups (A 1 and A 2 is an ethylene group), oxypropylene group (A 1 and A 2 is a 2-methylethylene group) alone or a mixture (block or random) of oxyethylene and oxypropylene groups, more preferably an oxyethylene group or an oxypropylene group, and particularly preferably an oxyethylene group (A is an ethylene group). 1 and A 2 is an ethylene group (-CH2CH2-).

[0030] In formula (1), n ​​and m are A 1 O and A 2represents the average number of moles of oxyalkylene groups represented by O added, and each independently represents a number of 1 to 6, with n+m=2 to 10. n and m are each independently preferably a number of 1 to 5, more preferably a number of 1 to 4, even more preferably a number of 1 to 3, and particularly preferably 1 or 2. n+m is preferably a number of 2 to 8, more preferably a number of 2 to 6, even more preferably a number of 2 to 5, particularly preferably a number of 2 to 4, and most preferably 2. According to one embodiment, n and m are each independently a number of 1 to 4, with n+m=2 to 5. According to one embodiment, n and m are each independently a number of 1 to 2, with n+m=2 to 3.

[0031] In the hydrotropic agent according to this embodiment, two or more compounds represented by formula (1) may be used in combination.

[0032] The compound represented by formula (1) may be synthesized or a commercially available product may be used. When synthesizing the compound represented by formula (1), for example, a saturated or unsaturated hydrocarbon group (R 1 The compound can be synthesized by a known method, for example, by adding an alkylene oxide to an alkylamine having an alkyl chain of the formula:

[0033] Commercially available products of the compound represented by formula (1) include amino alcohol MDA, amino alcohol MED, amino alcohol MBD, and amino alcohol tr-BDEA manufactured by Nippon Nyukazai Co., Ltd.; MDEOA and BDEA manufactured by BASF; and MDEA and DMEA manufactured by Huntsman.

[0034] The hydrotropic agent according to this embodiment can exhibit solubilizing properties in alkaline compositions containing nonionic surfactants. A preferred use of the hydrotropic agent according to this embodiment can be as a hydrotropic agent that solubilizes nonionic surfactants in alkaline compositions containing nonionic surfactants. Therefore, according to another embodiment of the present invention, a nonionic surfactant-containing alkaline composition containing the hydrotropic agent is provided. By using the hydrotropic agent according to this embodiment as a hydrotropic agent in a nonionic surfactant-containing alkaline composition, excellent solubilization of electrolytes and nonionic surfactants can be achieved in the alkaline composition, and the stability of the resulting alkaline composition can be significantly improved.

[0035] The hydrotrope agent according to this embodiment is preferably one that, when combined with a nonionic surfactant, sodium hydroxide as an alkali, and pure water as a dispersion medium, solubilizes the nonionic surfactant at 20°C to form a transparent composition. Specifically, in a preferred embodiment, the composition is placed in a beaker and stirred for 1 minute using a stirrer and a magnetic stirrer. If the temperature of the composition rises above 20°C due to the heat of dissolution, the composition is cooled to 20°C, and the transparency of the composition is confirmed visually at 20°C. Here, the composition is preferably transparent despite its higher alkali (sodium hydroxide) concentration. Specifically, the composition is preferably transparent in the following composition (A), more preferably in the following composition (B), even more preferably in the following composition (C), particularly preferably in the following composition (D), and particularly preferably in the following composition (E); (A) 20 parts by mass of nonionic surfactant, 59 parts by mass of hydrotropic agent, 8 parts by mass of sodium hydroxide, 13 parts by mass of pure water; (B) 20 parts by mass of nonionic surfactant, 59 parts by mass of hydrotropic agent, 9 parts by mass of sodium hydroxide, 12 parts by mass of pure water; (C) 20 parts by mass of nonionic surfactant, 59 parts by mass of hydrotropic agent, 10 parts by mass of sodium hydroxide, 11 parts by mass of pure water; (D) 20 parts by mass of nonionic surfactant, 59 parts by mass of hydrotropic agent, 11 parts by mass of sodium hydroxide, 10 parts by mass of pure water; (E) 2 parts by mass of nonionic surfactant, 5.9 parts by mass of hydrotropic agent, 1 part by mass of sodium hydroxide, 91.1 parts by mass of pure water.

[0036] The hydrotrope agent according to this embodiment is preferably one that, when combined with a nonionic surfactant, sodium hydroxide as an alkali, and pure water as a dispersion medium, solubilizes the nonionic surfactant at 40°C to form a transparent composition. Specifically, in a preferred embodiment, the composition is placed in a beaker, heated on a hot plate while stirring with a stir bar and a magnetic stirrer, and the transparency of the composition at 40°C is visually confirmed to be transparent. Here, the composition is preferably transparent despite having a higher alkali (sodium hydroxide) concentration. Specifically, the composition is preferably transparent in the composition (C) below, and more preferably transparent in the composition (E) below; (C) 20 parts by mass of nonionic surfactant, 59 parts by mass of hydrotropic agent, 10 parts by mass of sodium hydroxide, 11 parts by mass of pure water; (E) 2 parts by mass of nonionic surfactant, 5.9 parts by mass of hydrotropic agent, 1 part by mass of sodium hydroxide, 91.1 parts by mass of pure water.

[0037] The hydrotrope agent according to the present invention can also be suitably used in applications other than cleaning compositions. For example, the hydrotrope agent according to the present invention can also be used in cosmetic compositions, pharmaceutical compositions, lubricants, etc.

[0038] [Alkaline composition] As described above, one aspect of the present invention provides an alkaline composition in which a nonionic surfactant is solubilized using the hydrotropic agent. Although there are no particular limitations on the alkaline composition according to this aspect, preferred aspects of the alkaline composition are described below.

[0039] Nonionic surfactants The alkaline composition according to this embodiment contains a nonionic surfactant. There is no particular limitation on the specific form of the nonionic surfactant, and examples thereof include polyoxyalkylene alkyl ethers such as polyoxyethylene alkyl ethers; polyoxyalkylene alkylphenyl ethers such as polyoxyethylene alkylphenyl ethers; fatty acid esters having a structure in which a polyhydric alcohol (for example, glycerin, sorbitol, sucrose, etc.) and a fatty acid are ester-bonded (for example, glycerin fatty acid esters, sorbitan fatty acid esters, sucrose fatty acid esters, etc.); polyoxyalkylene fatty acid esters such as polyoxyethylene fatty acid esters in which ethylene oxide is added to these fatty acid esters; and polyoxyalkylene alkylamines such as polyoxyethylene alkylamines.

[0040] The nonionic surfactant preferably has an HLB value of 6 to 18 (more preferably 10 to 17). Examples of such nonionic surfactants include polyoxyethylene alkyl ethers in which the average number of moles of oxyethylene groups added is 1 to 60 and the alkyl group has 6 to 20 carbon atoms. Such nonionic surfactants may be synthesized or commercially available products may be used.

[0041] According to one embodiment, the nonionic surfactant is preferably a compound represented by the following formula (2):

[0042] [ka]

[0043] Here, in the above formula (2), R 2represents a saturated or unsaturated monovalent hydrocarbon group having 6 to 20 carbon atoms. Here, the saturated or unsaturated hydrocarbon group may be linear, branched, or cyclic. Examples of the saturated or unsaturated hydrocarbon group include an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, a cycloalkenyl group, a cycloalkynyl group, and an aryl group.

[0044] R in the above formula (2) 2 Examples of alkyl groups represented by the formula (I) include linear or branched alkyl groups having 6 to 20 carbon atoms, such as n-hexyl, cyclohexyl, 1,3-dimethylbutyl, 1-isopropylpropyl, 1,2-dimethylbutyl, n-heptyl, 1,4-dimethylpentyl, 2-methyl-1-isopropylpropyl, 1-ethyl-3-methylbutyl, n-octyl, 2-ethylhexyl, decyl, n-undecyl, 1-methyldecyl, 1-ethylnonyl, n-dodecyl, n-tridecyl, n-tetradecyl, 1-methyltridecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, and n-nonadecyl. From the viewpoint of availability, alkyl groups having 6 to 18 carbon atoms are preferred, and 2-ethylhexyl, dodecyl, and tridecyl are more preferred.

[0045] R in the above formula (2) 2 Examples of the alkenyl group represented by the formula: include alkenyl groups having 6 to 20 carbon atoms, such as a 1-hexenyl group, a 5-hexenyl group, and a 2-octenyl group.

[0046] R in the above formula (2) 2 Examples of the alkynyl group represented by the formula: include alkynyl groups having 6 to 20 carbon atoms, such as a 1-hexynyl group, a 3-methyl-1-butynyl group, and a 3,3-dimethyl-1-butynyl group.

[0047] R in the above formula (2) 2Examples of the cycloalkyl group represented by the formula (2) include cycloalkyl groups having 6 to 20 carbon atoms, such as a cyclohexyl group, a norbornyl group, and an adamantyl group. 2 Examples of the cycloalkenyl group represented by the formula (2) include cycloalkenyl groups having 6 to 20 carbon atoms, such as a cyclohexenyl group, a cycloheptenyl group, a cyclooctenyl group, and a cyclodecenyl group. 2 Examples of the cycloalkynyl group represented by the formula: include cycloalkynyl groups having 6 to 20 carbon atoms, such as a cyclohexynyl group, a cycloheptynyl group, a cyclooctynyl group, and a cyclodecynyl group.

[0048] R in the above formula (2) 2 Examples of the aryl group having 6 to 20 carbon atoms represented by the formula (I) include a phenyl group, a methylphenyl group, a dimethylphenyl group, a biphenyl group, a 1-naphthyl group, a 2-naphthyl group, a 9-anthryl group, a 9-phenanthryl group, a 1-pyrenyl group, a 5-naphthacenyl group, a 1-indenyl group, a 2-azulenyl group, a 9-fluorenyl group, a terphenyl group, a quaterphenyl group, a mesityl group, a pentalenyl group, a binaphthalenyl group, a ternaphthalenyl group, a heptalenyl group, a biphenylenyl group, an indacenyl group, a fluoranthenyl group, an acenaphthylenyl group, an acene Examples of the alkyl group include a trilenyl group, a phenalenyl group, a fluorenyl group, an anthryl group, a bianthracenyl group, a teranthracenyl group, a quaternanthracenyl group, an anthraquinolyl group, a phenanthryl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a pleiadenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a pentacenyl group, a tetraphenylenyl group, a hexaphenyl group, a hexacenyl group, a rubicenyl group, a coronenyl group, a trinaphthylenyl group, a heptaphenyl group, a heptacenyl group, a pyrantrenyl group, and an ovalenyl group.

[0049] R 2is preferably an alkyl group or cycloalkyl group having 6 to 20 carbon atoms, more preferably an alkyl group having 6 to 20 carbon atoms, even more preferably an alkyl group having 6 to 18 carbon atoms, particularly preferably an alkyl group having 8 to 16 carbon atoms, and most preferably an alkyl group having 8 to 14 carbon atoms.

[0050] In the above formula (2), A 3 is a linear or branched alkylene group having 2 to 4 carbon atoms. Examples of such alkylene groups include propylene groups such as an ethylene group (-(CH2)2-), an n-propylene group (-(CH2)3-), and an isopropylene group (-CH2-CH(CH3)-, -CH(CH3)-CH2-), and butylene groups such as an n-butylene group (-(CH2)4-), a 1-methylpropylene group (-CH2-CH2-CH(CH3)-, -CH(CH3)-CH2-CH2-), a 2-methylpropylene group (-CH2-CH(CH3)-CH2-), a dimethylethylene group (-CH2-C(CH3)2-, -C(CH3)2-CH2-), and an ethylethylene group (-CH2-CH(CH2CH3)-, -CH(CH2CH3)-CH2-).

[0051] In the above formula (2), (A 3 O) p represents a polyoxyalkylene chain. 3 O) p may contain two or more types of oxyalkylene groups. 3 O) p It is preferable that (AO) contains an oxyethylene group (-O-(CH2)2-), but it may contain an oxyalkylene group other than the oxyethylene group (-O-(CH2)2-). p When has two or more kinds of oxyalkylene groups, the arrangement may be either random or block.

[0052] In the above formula (2), p is A 3It represents the average number of moles of O added, and is a number from 1 to 60. From the viewpoint of the effect of improving cleaning performance, p is preferably a number from 2 to 40, more preferably a number from 2 to 30, and particularly preferably a number from 3 to 20. 3 O) p When has two or more kinds of oxyalkylene groups, p represents the total number of moles of the two or more kinds of oxyalkylene groups added.

[0053] The content of the nonionic surfactant in the alkaline composition according to this embodiment is not particularly limited, but is preferably 1 to 80% by mass relative to 100% by mass of the total amount of the composition. From the viewpoint of improving cleaning properties, the content of the nonionic surfactant is preferably 1 to 50% by mass, more preferably 1 to 40% by mass, even more preferably 1 to 35% by mass, particularly preferably 1 to 30% by mass, and most preferably 1 to 25% by mass relative to 100% by mass of the total amount of the composition.

[0054] Alkaline compounds The alkaline composition according to this embodiment contains an alkaline compound. The alkaline compound can be appropriately selected from various alkaline compounds that have the function of increasing the pH of the cleaning composition in which the alkaline compound is dissolved. There are no particular limitations on the specific form of the alkaline compound, but it is preferably an inorganic basic compound. As the inorganic basic compound, inorganic basic compounds such as alkali metal hydroxides, alkaline earth metal hydroxides, various carbonates, and hydrogen carbonates can be used. Such basic compounds may be used alone or in combination of two or more.

[0055] Specific examples of alkali metal hydroxides include potassium hydroxide, sodium hydroxide, ammonium hydroxide, etc. Specific examples of alkaline earth metal hydroxides include calcium hydroxide, magnesium hydroxide, etc. Specific examples of carbonates and bicarbonates include ammonium bicarbonate, ammonium carbonate, potassium bicarbonate, potassium carbonate, sodium bicarbonate, sodium carbonate, etc. Of these, potassium hydroxide and sodium hydroxide are preferred from the viewpoint of increasing the pH.

[0056] The alkaline composition according to this embodiment is not particularly limited in terms of the content of the alkaline compound, but from the viewpoint of improving cleaning properties, the content of the alkaline compound is preferably 0.5 to 30 mass%, more preferably 1 to 25 mass%, even more preferably 3 to 20 mass%, particularly preferably 5 to 20 mass%, and most preferably 6 to 20 mass%, relative to 100 mass% of the total amount of the composition. According to one embodiment, the alkaline composition according to this embodiment has a content of the alkaline compound of 8 to 15 mass%, 9 to 13 mass%, or 9 to 12 mass%.

[0057] ·water The alkaline composition according to this embodiment preferably contains water as a dispersion medium. While there are no particular limitations on the water content, from the viewpoint of dissolving the nonionic surfactant and alkaline compound, the water content is preferably 0.5 to 50 mass%, more preferably 1 to 40 mass%, even more preferably 3 to 35 mass%, particularly preferably 5 to 30 mass%, and most preferably 6 to 25 mass%, relative to 100 mass% of the total amount of the composition. According to one embodiment, the alkaline composition according to this embodiment has a water content of 8 to 25 mass%, 9 to 25 mass%, 10 to 25 mass%, 15 to 25 mass%, or 15 to 20 mass%.

[0058] pH The pH of the alkaline composition of this embodiment can be adjusted to a range of greater than 7.0, 7.2 or greater, 7.3 or greater, 7.5 or greater, or 8.0 or greater. In some embodiments, the pH of the alkaline composition of this embodiment is 8.5 or greater, 9.0 or greater, greater than 9.0, 9.5 or greater, 10 or greater, 10.5 or greater, or 11 or greater. In some embodiments, the pH of the alkaline composition of this embodiment can be 14.0 or less. In some embodiments, the pH of the alkaline composition of this embodiment is 9.0 to 14.0 or less, 9.5 to 14.0 or less, 10.0 to 14.0 or less, 11.0 to 14.0 or less, 11.5 to 14.0 or less, or 12.0 to 14.0 or less.

[0059] In the alkaline composition of this embodiment, the mass ratio of the alkaline compound to the nonionic surfactant (alkaline compound:nonionic surfactant) is preferably 1:99 to 70:30, more preferably 5:95 to 60:40, even more preferably 10:90 to 50:50, particularly preferably 15:85 to 40:60, and most preferably 18:82 to 35:65.

[0060] In the alkaline composition of this embodiment, the mass ratio of the hydrotropic agent to the nonionic surfactant (hydrotropic agent:nonionic surfactant) is preferably 10:90 to 95:5, more preferably 20:80 to 90:10, even more preferably 30:70 to 90:10, particularly preferably 40:60 to 85:15, and most preferably 50:50 to 80:20.

[0061] In the alkaline composition according to this embodiment, the mass ratio of the hydrodrop agent to the alkaline compound (hydrodrop agent: alkaline compound) is preferably 50:50 to 99:1, more preferably 60:40 to 98:2, even more preferably 70:30 to 97:3, particularly preferably 75:25 to 95:5, and most preferably 80:20 to 93:7. According to one embodiment, the mass ratio of the hydrodrop agent to the alkaline compound (hydrodrop agent: alkaline compound) is 80:20 to 90:10, 83:17 to 90:10, 85:15 to 90:10, 80:20 to 89:11, 80:20 to 88:12, or 83:17 to 88:12.

[0062] According to one embodiment, the alkaline composition according to this embodiment contains 90% by mass of water, and the mass ratio of the hydrotrope to the nonionic surfactant (hydrotrope:nonionic surfactant) is preferably 10:90 to 95:5, more preferably 20:80 to 90:10, even more preferably 30:70 to 90:10, particularly preferably 40:60 to 85:15, and most preferably 50:50 to 80:20.

[0063] The alkaline composition according to the present invention may contain one or more conventional additives in addition to the nonionic surfactant, alkaline compound, and water. Examples of such additives include solubilizers other than the hydrotropic agent (solubilizers other than the compound represented by formula (1)), pH adjusters such as chelating agents and buffers, enzymes, viscosity adjusters, thickeners, surface modifiers, antioxidants, UV absorbers, preservatives, antibacterial agents, dispersants, antifoaming agents, rust inhibitors, polymeric compounds other than the nonionic surfactants (e.g., anionic surfactants), and dispersion media other than water (e.g., polyhydric alcohols such as glycerin and butylene glycol).

[0064] The method for producing the alkaline composition according to this embodiment is not particularly limited, and may involve, for example, mixing the hydrotrope with the components of the cleaning composition (e.g., a nonionic surfactant, an alkaline compound, water, and, if necessary, additives). The temperature during mixing is not particularly limited, but is preferably 10 to 60°C, more preferably 15 to 45°C, even more preferably 15 to 40°C, and particularly preferably 15 to 35°C. The mixing time is also not particularly limited, and may be, for example, 10 to 120 minutes, as long as the components of the alkaline composition are uniformly mixed.

[0065] A preferred application of the alkaline composition according to this embodiment is a cleaning composition. That is, the nonionic surfactant-containing alkaline composition can be a cleaning composition. Therefore, another embodiment of the present invention can be a cleaning composition containing the above-mentioned hydrotrope agent. By using the above-mentioned hydrotrope agent as the hydrotrope agent in the cleaning composition, excellent solubilization of electrolytes and nonionic surfactants can be achieved in the cleaning composition, and the stability and detergency of the resulting cleaning composition can be significantly improved.

[0066] The alkaline composition according to the present embodiment is not particularly limited in terms of the object to be cleaned, as long as it is used as a cleaning agent. Examples of cleaning applications include a multipurpose cleaning agent, a cleaning agent for hard surfaces, a cleaning agent for electronic materials, a cleaning agent for clothing, a cleaning agent for sanitary utensils, a cleaning agent for automobiles, and a cleaning agent for clean-in-place (CIP).

[0067] The alkaline composition according to the present invention can contain high concentrations of alkaline compounds and nonionic surfactants, resulting in excellent cleaning properties. Because the alkaline compounds and nonionic surfactants are well solubilized by the hydrotropic agent, the alkaline composition according to the present invention is less likely to become unstable even when diluted with water. Therefore, the alkaline composition according to the present invention can be appropriately diluted as needed for storage or use. Therefore, the cleaning composition according to the present invention also has the advantage of being easy to handle.

[0068] The alkaline composition according to the present invention can be suitably used in applications other than cleaning compositions. For example, the alkaline composition according to the present invention can be used in cosmetic compositions, pharmaceutical compositions, lubricants, etc.

[0069] Although the embodiments of the present invention have been described in detail, it is clear that this is for illustrative and exemplary purposes only and not for limitation, and that the scope of the present invention should be interpreted by the appended claims.

[0070] The present invention encompasses the following aspects and configurations.

[0071] [1] Formula (1):

[0072] [ka]

[0073] In formula (1), R 1 represents a saturated or unsaturated hydrocarbon group having 1 to 10 carbon atoms, A 1 and A 2 each independently represents a linear or branched alkylene group having 2 to 4 carbon atoms, n and m are A 1 O and A 2represents the average number of moles of oxyalkylene groups added, each independently being a number of 1 to 6, and n+m=2 to 10; a hydrotropic agent for a nonionic surfactant-containing alkaline composition, comprising a compound represented by the formula: [2]A 1 and A 2 is an ethylene group; [3]R 1 is an alkyl group having 2 to 6 carbon atoms; [4] The hydrotropic agent according to any one of the above [1] to [3], wherein n and m are each independently a number from 1 to 4, and n+m=2 to 5; [5]R 1 is an alkyl group having 2 to 4 carbon atoms, n and m are each independently a number of 1 or 2, and n+m=2 to 3; [6] The hydrotropic agent according to any one of the above [1] to [5], wherein the compound represented by formula (1) is n-butyldiethanolamine; [7] The hydrotropic agent according to any one of [1] to [6] above, wherein a composition consisting of 20 parts by mass of the nonionic surfactant, 59 parts by mass of the hydrotropic agent, 8 parts by mass of sodium hydroxide, and 13 parts by mass of pure water is placed in a beaker and stirred for 1 minute using a stirring bar and a magnetic stirrer, and when the temperature of the composition reaches 20°C or higher due to heat of dissolution, the composition is cooled to 20°C, and the transparency of the composition is confirmed visually at 20°C, and the composition is transparent; [8] An alkaline composition comprising the hydrotropic agent according to any one of [1] to [7] above, a nonionic surfactant, an alkaline compound, and water; [9] The alkaline composition according to [8] above, which is a cleaning composition. [Example]

[0074] The effects of the present invention will be explained using the following examples and comparative examples. However, the technical scope of the present invention is not limited to the following examples. In the following description, "parts" means parts by mass, and "%" means % by mass. In the following examples, unless otherwise specified, operations were performed at 25°C.

[0075] [Notation of the compound represented by formula (1) and comparative compounds] Hereinafter, the compound represented by formula (1) (compound (1)) will be referred to as "Cx monoalkylamine diEOy" (where x in Cx represents the number of carbon atoms, EO represents ethylene oxide, and y in EOy represents the number of moles of EO (ethylene oxide) added (total number)). Comparative compounds will be referred to as "Cx dialkylamine monoEOy" (where x in Cx represents the number of carbon atoms, and y in EOy represents the number of moles of EO added (total number)); and "Cx monoalkylamine monoEOy" (where x in Cx represents the number of carbon atoms, and y in EOy represents the number of moles of EO added (total number)).

[0076] [Preparation of the compound represented by formula (1) and comparative compounds] [Production Example 1: C3 monoalkylamine diEO2 (Compound 2 below)] A stainless steel autoclave equipped with a stirrer, a thermometer, and an EO inlet tube was charged with 50 parts by mass of propylamine (manufactured by Tokyo Chemical Industry Co., Ltd.) and purged with nitrogen. Then, 2 moles (74.5 parts by mass) of ethylene oxide per mole of propylamine were fed and added to the autoclave at an initial nitrogen pressure of 0.05 MPa and 145±5°C, yielding the target C3 monoalkylamine diEO2.

[0077] [Production Example 2: C3 monoalkylamine diEO3 (Compound 3 below)] The target C3 monoalkylamine diEO3 was obtained in the same manner as in Production Example 1, except that the number of moles of ethylene oxide added was changed to 3 moles (111.8 parts by mass) per mole of propylamine.

[0078] [Production Example 3: C3 monoalkylamine diEO4 (Compound 4 below)] The target C3 monoalkylamine diEO4 was obtained in the same manner as in Production Example 1, except that the number of moles of ethylene oxide added was changed to 4 moles (149.1 parts by mass) per mole of propylamine.

[0079] [Production Example 4: C4 monoalkylamine diEO4 (Compound 6 below)] The target C4 monoalkylamine diEO4 was obtained in the same manner as in Production Example 1, except that the raw material was changed to 50 parts by mass of butylamine (manufactured by Tokyo Chemical Industry Co., Ltd.) and the number of moles of ethylene oxide added was changed to 4 moles (120.5 parts by mass) per mole of butylamine.

[0080] [Production Example 5: C6 monoalkylamine diEO2 (Compound 7 below)] The target C6 monoalkylamine diEO2 was obtained in the same manner as in Production Example 1, except that the raw material was changed to 50 parts by mass of hexylamine (manufactured by Tokyo Chemical Industry Co., Ltd.) and the number of moles of ethylene oxide added was changed to 2 moles (43.6 parts by mass) per mole of hexylamine.

[0081] [Production Example 6: C6 monoalkylamine diEO3 (Compound 8 below)] The target C6 monoalkylamine diEO3 was obtained in the same manner as in Production Example 5, except that the number of moles of ethylene oxide added was changed to 3 moles (65.3 parts by mass) per mole of hexylamine.

[0082] [Production Example 7: C6 monoalkylamine diEO4 (Compound 9 below)] The target C6 monoalkylamine diEO4 was obtained in the same manner as in Production Example 5, except that the number of moles of ethylene oxide added was changed to 4 moles (87.1 parts by mass) per mole of hexylamine.

[0083] [Production Example 8: Comparative Compound C1 Dialkylamine Mono EO4 (Compound 11 below)] The target C1 dialkylmono EO4 was obtained in the same manner as in Production Example 1, except that the raw material was changed to 50 parts by mass of dimethylaminoethanol (manufactured by Nippon Nyukazai Co., Ltd.) and the number of moles of ethylene oxide added was changed to 3 moles (74.1 parts by mass) per mole of dimethylamine part of dimethylaminoethanol.

[0084] [Evaluation of solubilization performance] The solubilizing ability of each compound was evaluated using the compounds listed in Table 1 below.

[0085] In the table below, compounds 1 to 10 are compounds represented by formula (1), and compounds 11 to 22 are comparative compounds.

[0086] [Table 1]

[0087] [composition] Solubilization studies were carried out using compositions (a) and (b). Composition (b) corresponds to a 10-fold dilution of composition (a) containing 10.0% by weight of sodium hydroxide. In the compositions below, a nonionic surfactant (Newcol 1004 (manufactured by Nippon Nyukazai Co., Ltd.) or Newcol 2306-Y (manufactured by Nippon Nyukazai Co., Ltd.)) was used as the surfactant. The compositions below indicate the amount of pure sodium hydroxide. Composition (a): 20.0 parts by weight of nonionic surfactant, 59.0 parts by weight of hydrotropic agent, 1.0 to 11.0 parts by weight of sodium hydroxide, balance parts by weight of pure water (balance parts by weight to make the total amount of the composition 100 parts by weight) Composition (b): 2.0 parts by mass of nonionic surfactant, 5.9 parts by mass of hydrotropic agent, 1.0 part by mass of sodium hydroxide, 91.1 parts by mass of pure water.

[0088] [Solubility evaluation method] ≪Solubility at room temperature (20℃)≫ (1) Place the above-mentioned composition (a or b) into a beaker. (2) The composition in the beaker is stirred for 1 minute using a stirring bar and a magnetic stirrer, while measuring the temperature of the composition using a thermometer. (3) If the temperature of the composition rises above 20°C due to the heat of dissolution, cool the composition until the temperature reaches 20°C (room temperature). (4) The transparency of the composition is visually confirmed under a temperature condition of 20°C, and if it is transparent, it is rated as ○, and if it is cloudy, it is rated as ×. In the visual transparency test, "transparent" is defined as follows: a thermometer (model HG451-100, manufactured by Ando Keiki Seikosho Co., Ltd., size 6 mm diameter x 450 mm length) is placed in the center of a 100 mL beaker containing 100 mL of composition, the beaker is placed against a black background, and when the inside of the beaker is viewed from the side, the value on the thermometer scale can be accurately read through the composition (the scale lines can be seen). If the value on the thermometer scale can be accurately read, it is rated as "transparent" (rated as ○), and if the value on the thermometer scale cannot be accurately read, it is rated as "cloudy" (rated as ×).

[0089] ≪Solubility at 40℃≫ (1) The composition in the beaker used in the room temperature solubility evaluation is heated on a hot plate while being stirred using a stirring bar and a magnetic stirrer, and the temperature of the composition is adjusted to 40°C. (2) The transparency of the composition at 40° C. is visually confirmed, and if it is transparent, it is evaluated as ○, and if it is cloudy, it is evaluated as ×. The visual transparency test is carried out in the same manner as above.

[0090] The results of the solubility evaluation are shown in Tables 2 to 4. The solubility evaluation was performed for each composition using Newcol 1004 and Newcol 2306-Y as the surfactant, but the solubility evaluation results were the same for both, so Tables 2 to 4 show only the results using Newcol 1004 (referred to as N-1004 in the tables) as the surfactant.

[0091] [Table 2]

[0092] [Table 3]

[0093] [Table 4]

[0094] The results shown in Tables 2 to 4 demonstrate that good solubilization is possible by using the compounds of the Examples as hydrotropic agents.

Claims

1. The following formula (1): 【Chemistry 1】 In formula (1), R １ represents a saturated or unsaturated hydrocarbon group having 1 to 10 carbon atoms, A １ and A ２ each independently represents a linear or branched alkylene group having 2 to 4 carbon atoms, n and m are A １ O and A ２ represents the average number of moles of oxyalkylene groups represented by O added, and each independently represents a number of 1 to 6, and n+m=2 to 10; A hydrotropic agent for a nonionic surfactant-containing alkaline composition, comprising a compound represented by the formula:

2. A １ and A ２ The hydrotropic agent of claim 1 , wherein is an ethylene group.

3. R １ The hydrotropic agent according to claim 1 or 2, wherein is an alkyl group having 2 to 6 carbon atoms.

4. The hydrotropic agent according to claim 1 or 2, wherein n and m are each independently a number from 1 to 4, and n+m=2 to 5.

5. R １ The hydrotropic agent according to claim 1 or 2, wherein n is an alkyl group having 2 to 4 carbon atoms, n and m are each independently a number from 1 to 2, and n+m=2 to 3.

6. The hydrotropic agent according to claim 1 or 2, wherein the compound represented by formula (1) is n-butyldiethanolamine.

7. The hydrotrope agent according to claim 1 or 2, wherein a composition consisting of 20 parts by mass of the nonionic surfactant, 59 parts by mass of the hydrotrope agent, 8 parts by mass of sodium hydroxide, and 13 parts by mass of pure water is placed in a beaker and stirred for 1 minute using a stirring bar and a magnetic stirrer, and when the temperature of the composition reaches 20°C or higher due to heat of dissolution, the composition is cooled to 20°C, and the transparency of the composition is confirmed visually at 20°C.

8. An alkaline composition comprising the hydrotropic agent according to claim 1 or 2, a nonionic surfactant, an alkaline compound, and water.

9. The alkaline composition according to claim 8, which is a cleaning composition.

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