JP7531344B2 - How to wash textile products - Google Patents

Description

The present invention relates to a method for washing textile products.

In recent years, in order to reduce the time required for laundry, an increasing number of households are washing several days' worth of laundry at once, or loading a large amount of laundry into a washing machine. In loading a large amount of laundry, dirt is likely to adhere to the laundry because the laundry is left for a long time. In loading a large amount of laundry, the ratio of the laundry to the cleaning liquid is high, so dirt removed during washing is likely to adhere to the laundry again, resulting in recontamination. Therefore, loading a large amount of laundry or loading a large amount of laundry is a laundry environment that makes it difficult to remove dirt.
In order to improve the cleaning performance against stubborn stains, a method is known in which a liquid detergent is directly applied to the stained area of the item to be washed, and the item is left to stand for 30 minutes to 24 hours before being washed as usual (see, for example, Patent Document 1).

JP 2018-188785 A

However, there is still room for improvement in the washing method described in Patent Document 1, and there is a demand for further improvement in the cleaning power against stubborn stains such as oily stains.
Furthermore, according to Patent Document 1, it is preferable to leave the detergent for 12 hours or more after application, but this takes a long time to complete washing, which is a significant time burden.
The inventors then heated the items to be washed with liquid detergent before washing, hoping to improve cleaning power and shorten the time the items were left on the surface after application.However, they discovered that depending on the heating temperature and type of liquid detergent, yellowing may progress and sufficient cleaning power may not be obtained for yellowed stains.

The present invention aims to provide a washing method that can improve the cleaning power against yellowing stains and oily stains.

The present invention has the following aspects.
[1] A method for washing a textile product, comprising applying a liquid detergent containing a surfactant (excluding higher fatty acid salts) including a nonionic surfactant (A) to the textile product, subjecting the textile product to a heat treatment at 20 to 70°C, and then contacting the textile product with water to perform a washing treatment.
[2] The method for washing a textile product according to [1], wherein the heat treatment time is 5 to 120 minutes.
[3] The method for washing textile products according to [1] or [2], wherein the liquid detergent further contains a water-miscible organic solvent (C).
[4] The method for washing a textile product according to [3], wherein the water-miscible organic solvent (C) is at least one selected from the group consisting of 3-methoxy-3-methyl-1-butanol, butyl carbitol, and phenoxyethanol.
[5] The method for washing a textile product according to any one of [1] to [4], wherein the liquid detergent further contains one or more compounds (B) selected from the group consisting of higher fatty acids and salts thereof.
[6] The method for washing a textile product according to any one of [1] to [5], wherein the surfactant further comprises an anionic surfactant (D).
[7] The method for washing textile products according to any one of [1] to [6], wherein the liquid detergent further contains water.
[8] The method for washing a textile product according to any one of [1] to [7], wherein the content of the nonionic surfactant (A) is 10 to 80 mass% based on the total mass of the liquid detergent.
[9] The method for washing a textile product according to any one of [1] to [8], wherein the amount of water used in the washing treatment is 30 times or more the amount of the detergent used in the washing treatment.

The present invention provides a washing method that can improve the cleaning power against yellowing stains and oily stains.

The present invention will be described in detail below.
In this specification, the textile product to be washed is also referred to as "item to be washed."
In this specification, the water-miscible organic solvent refers to an organic solvent that dissolves in an amount of 50 g or more in 1 L of ion-exchanged water at 25°C.

"Liquid cleaning agent"
The liquid detergent (α) used in the method for washing textile products of the present invention is a composition containing a surfactant (excluding higher fatty acid salts).
The total content of the surfactants is preferably 40% by mass or more, more preferably 50% by mass or more, and even more preferably 60% by mass or more, based on the total mass of the liquid detergent (α). The total content of the surfactants is preferably 80% by mass or less, more preferably 75% by mass or less, and even more preferably 70% by mass or less. That is, the total content of the surfactants is preferably 40 to 80% by mass, more preferably 50 to 75% by mass, and even more preferably 60 to 70% by mass, based on the total mass of the liquid detergent (α). If the total content of the surfactants is equal to or more than the lower limit, the cleaning power is superior, and if it is equal to or less than the upper limit, the liquid stability of the liquid detergent (α) is superior.

The surfactant contains at least a nonionic surfactant (A) (hereinafter, also referred to as "component (A)").
The liquid detergent (α) may contain a surfactant other than component (A), for example, one or more selected from the group consisting of an anionic surfactant (D) (hereinafter also referred to as "component (D)"), a cationic surfactant (E) (hereinafter also referred to as "component (E)"), and an amphoteric surfactant. In other words, the surfactant may further contain one or more selected from the group consisting of component (D), component (E) and amphoteric surfactant.
The surfactant preferably contains the (A) component and at least one of the (D) component and the (E) component, and more preferably contains at least the (A) component and the (D) component from the viewpoint of superior cleaning power against stubborn stains such as oil stains (particularly chili oil stains).

It is preferable that the liquid detergent (α) further contains one or more of one or more compounds (B) selected from the group consisting of higher fatty acids and their salts (hereinafter also referred to as "component (B)"), a water-miscible organic solvent (C) (hereinafter also referred to as "component (C)"), and water.
The liquid detergent (α) may further contain a propylene oxide adduct of a trihydric alcohol (F) (hereinafter also referred to as “component (F)”).
In addition, the liquid detergent (α) may further contain, in addition to the above-mentioned components, components (optional components) that are known in liquid detergents for textile products, as long as the effects of the present invention are not impaired.

<Component (A)>
The component (A) is a nonionic surfactant.
As the nonionic surfactant, a nonionic surfactant used in a liquid detergent for textile products can be used. The component (A) may be used alone or in combination of two or more kinds.
The compound represented by the following general formula (I) (hereinafter also referred to as "compound (I)") is preferred as component (A) in that the liquid detergent (α) is less likely to gel when applied to a textile product and subjected to a heat treatment.
In addition, the compound represented by the following general formula (II) (hereinafter also referred to as "compound (II)") is preferred as component (A) in that it has superior cleaning power for removing yellow stains, oil stains, and the like.

R ¹ -C(=O)O-[(EO) _s /(PO) _t ]-(EO) _u - ^R2 ...(I)
R ³ -O-[(EO) _v /(PO) _w ]-(EO) _x -H...(II)
In formula (I), R ¹ is a hydrocarbon group having 7 to 22 carbon atoms, R ² is an alkyl group having 1 to 6 carbon atoms, and s represents the average number of repeats of EO, which is a number from 6 to 20. where t represents the average number of repeats of PO and is a number from 0 to 6, u represents the average number of repeats of EO and is a number from 0 to 20, EO represents an oxyethylene group, and PO represents an oxyethylene group. When t is 1 or more, the oxyethylene group and the oxypropylene group in [(EO) _s /(PO) _t ] may be randomly polymerized or block polymerized. Good too.
In formula (II), ^R3 is a hydrocarbon group having 7 to 22 carbon atoms, v represents the average number of repeats of EO and is a number from 3 to 20, w represents the average number of repeats of PO and is 0. 1 to 6, x represents the average number of repeats of EO and is a number from 0 to 20, EO represents an oxyethylene group, and PO represents an oxypropylene group. In the formula (EO) _v /(PO) _w ), the oxyethylene groups and the oxypropylene groups may be randomly polymerized or block polymerized.
The average number of repetitions can be measured by gas chromatography or the like.

In formula (II), ^R3 preferably has 10 to 22 carbon atoms, more preferably has 10 to 20 carbon atoms, and even more preferably has 10 to 18 carbon atoms.
In formula (II), ^R3 may be a straight-chain hydrocarbon group, or may be a group selected from a branched-chain primary hydrocarbon group and a straight-chain secondary hydrocarbon group.
In general formula (II), when ^R3 is a linear hydrocarbon group, v+x is preferably 3 to 22, more preferably 5 to 20, still more preferably 10 to 20, and particularly preferably 14 to 18. w is a number of 0 to 6, preferably 0 to 3, and more preferably 0.
In general formula (II), when ^R3 is a group selected from a branched primary hydrocarbon group and a linear secondary hydrocarbon group, v+x is preferably 3 to 10, more preferably 3 to 8, and w is preferably 0.

Compound (I) is preferably a polyoxyethylene fatty acid alkyl ester, and the number of carbon atoms in R ¹ is preferably 9 to 19, more preferably 11 to 17. R ² is preferably a methyl group. s+u is preferably 6 to 20, more preferably 6 to 18, even more preferably 11 to 18, and particularly preferably 14 to 16. t is preferably 0 to 3, more preferably 0. In particular, compounds in which R ¹ in formula (I) is an alkyl group having 11 carbon atoms and an alkyl group having 13 carbon atoms, or R ¹ is an alkyl group having 15 carbon atoms and an alkyl group or alkenyl group having 17 carbon atoms, s=15, t=0, and u=0 (hereinafter sometimes referred to as MEE) are more preferred.
Polyoxyethylene fatty acid alkyl esters, especially MEE, are nonionic surfactants with weak molecular orientation in aqueous solutions and unstable micelles. For this reason, polyoxyethylene fatty acid alkyl esters do not cause gelation or the like at high concentrations, and even if a large amount of one type is mixed into the liquid detergent (α), it is presumed that the solubility in water can be increased. In particular, by applying the liquid detergent (α) to a textile product and heating it at 20 to 70°C, the water and volatile solvent contained in the liquid detergent (α) are evaporated, so that the liquid detergent (α) is concentrated on the textile product. Even under such conditions, it is considered that the liquid detergent (α) containing polyoxyethylene fatty acid alkyl esters is quickly dispersed and becomes a cleaning solution when it comes into contact with water. In addition, the concentration of polyoxyethylene fatty acid alkyl esters in the cleaning solution quickly becomes uniform, and a cleaning solution of appropriate concentration can be brought into contact with the washed item (textile product) from the beginning of the cleaning process, and as a result, it is considered that a high cleaning power can be exhibited.

As the compound (I), among polyoxyethylene fatty acid alkyl esters, those having a narrow ratio, which indicates the distribution ratio of compounds having different numbers of moles of ethylene oxide added, of 20% by mass or more are preferred. The upper limit of the narrow ratio is preferably substantially 80% by mass or less. The narrow ratio is more preferably 20 to 60% by mass. The higher the narrow ratio, the better the detergency can be obtained, but if it is too high, there is a risk of reducing the liquid stability at low temperatures, so the narrow ratio is more preferably 25 to 40% by mass.
The narrow ratio of a polyoxyalkylene type nonionic surfactant such as a polyoxyethylene fatty acid alkyl ester is a value calculated by the following formula (S).

In formula (S), _Smax represents the number of moles of alkylene oxide added in the alkylene oxide adduct present in the largest amount in the polyoxyalkylene type nonionic surfactant (the value of s+t in formula (I)).
i represents the number of moles of alkylene oxide added.
Yi represents the proportion (mass %) of alkylene oxide adducts in which the number of moles of alkylene oxide added is i, present in the entire component represented by formula (S).
The narrow ratio can be controlled, for example, by the method for producing the polyoxyethylene fatty acid alkyl ester.

The method for producing polyoxyethylene fatty acid alkyl ester is not particularly limited, but an example thereof includes a method of addition polymerization of ethylene oxide to fatty acid alkyl ester using a surface-modified composite metal oxide catalyst (see JP-A-2000-144179).
Suitable examples of the surface-modified composite metal oxide catalyst include composite metal oxide catalysts such as magnesium oxide whose surface has been modified with a metal hydroxide or the like and to which a metal ion (Al ³⁺ , Ga ³⁺ , In ³⁺ , Tl ³⁺ , Co ³⁺ , Sc ³⁺ , La ³⁺ , Mn ²⁺ or the like) has been added, and calcined hydrotalcite catalysts whose surface has been modified with a metal hydroxide and/or a metal alkoxide or the like.
In the surface modification of the composite metal oxide catalyst, the ratio of the metal hydroxide and/or metal alkoxide is preferably 0.5 to 10 parts by mass, and more preferably 1 to 5 parts by mass, per 100 parts by mass of the composite metal oxide.
The method for producing polyoxyethylene fatty acid alkyl ester is not limited to the above-mentioned method.For example, polyoxyethylene fatty acid alkyl ester can also be produced by a method of adding alkylene oxide to fatty acid alkyl ester by using an alkoxylation catalyst prepared from a mixture of alkaline earth metal compound and oxyacid, etc.The above alkoxylation catalyst is disclosed in Japanese Patent No. 04977609, International Publication No. 1993/004030, International Publication No. 2002/038269, International Publication No. 2012/028435, etc., and examples thereof include an alkoxylation catalyst prepared from a mixture of alkaline earth metal salt of carboxylic acid and/or alkaline earth metal salt of hydroxycarboxylic acid and sulfuric acid, etc.

The content of component (A) is preferably 10 to 70 mass%, more preferably 20 to 60 mass%, and even more preferably 30 to 50 mass%, based on the total mass of the liquid detergent (α). When the content of component (A) is equal to or more than the lower limit, the cleaning power against yellowing stains and oily stains is superior, and when the content is equal to or less than the upper limit, the liquid detergent (α) has superior liquid stability.
When the content of the component (D) described later is 20 mass % or less, based on the total mass of the liquid detergent (α), the content of the component (A) is preferably 30 to 70 mass %, more preferably 30 to 60 mass %, and even more preferably 35 to 50 mass %, based on the total mass of the liquid detergent (α).
When the content of the component (D) exceeds 20 mass % based on the total mass of the liquid detergent (α), the content of the component (A) is preferably 10 to 35 mass %, more preferably 15 to 30 mass %, and even more preferably 15 to 25 mass %, based on the total mass of the liquid detergent (α).
The component (A) preferably contains one or more compounds selected from the group consisting of compound (I) and compound (II), and more preferably contains one or more compounds (I) and one or more compounds (II).
Based on the total mass of the component (A), the total content of compound (I) and compound (II) is preferably 60 to 100 mass%, more preferably 80 to 100 mass%, and even more preferably 90 to 100 mass%.
When compound (I) and compound (II) are used in combination, the content of compound (I) is preferably 5 to 60 mass%, more preferably 20 to 50 mass%, and even more preferably 25 to 40 mass%, based on the total mass of liquid detergent (α). The content of compound (II) is preferably 1 to 20 mass%, more preferably 3 to 15 mass%, and even more preferably 5 to 10 mass%, based on the total mass of liquid detergent (α).
The mass ratio of the content represented by compound (I)/compound (II) is preferably 0.5-20, more preferably 2-10, and even more preferably 4-8.
When component (A) contains compound (I), the proportion of MEE relative to the total mass of compound (I) is preferably 80 to 100 mass%, more preferably 85 to 100 mass%, and even more preferably 90 to 100 mass%.

<Component (B)>
Component (B) is one or more compounds selected from the group consisting of higher fatty acids and their salts. "Higher fatty acids" refers to fatty acids having 8 to 22 carbon atoms. Component (B) contributes to improving rinsing performance. When rinsing performance is improved, the number of rinsing steps after cleaning can be reduced.
The higher fatty acid is preferably a chain monocarboxylic acid having 8 to 18 carbon atoms. Specific examples include compounds represented by the general formula: R ¹¹ -COOH, where R ¹¹ is an aliphatic hydrocarbon group having 7 to 17 carbon atoms.
In the above formula, the aliphatic hydrocarbon group of R ¹¹ may be linear or branched, and is preferably a linear or branched alkyl group or a linear or branched alkenyl group. The aliphatic hydrocarbon group of R ¹¹ has 7 to 17 carbon atoms, and preferably has 11 to 17 carbon atoms. When R ¹¹ has 7 or more carbon atoms, the anti-soil redeposition effect is enhanced. On the other hand, when R ¹¹ has 17 or less carbon atoms, the solubility of component (B) in water is further increased.

Examples of the salt form of component (B) include alkali metal salts, alkaline earth metal salts, amine salts, and ammonium salts. Examples of alkali metal salts include sodium salts and potassium salts. Examples of alkaline earth metal salts include calcium salts and magnesium salts. Examples of amine salts include alkanolamine salts (monoethanolamine salts, diethanolamine salts, triethanolamine salts, and the like).
The component (B) may be used alone or in combination of two or more types.
Furthermore, component (B) may be a mixture of a single chain length, or a mixture of two or more chain lengths.

The mass ratio (A/B ratio) of the content of component (A)/component (B) is preferably 5 to 40, more preferably 5 to 35, and even more preferably 10 to 30. When the A/B ratio is equal to or less than the upper limit, good rinsing properties are easily obtained during cleaning treatment after applying the liquid detergent (α) to a textile product and subjecting it to a heat treatment. When the A/B ratio is equal to or more than the lower limit, the stability of the liquid detergent (α) is excellent.
The content of the (B) component is preferably 0.5 to 10% by mass, more preferably 1 to 8% by mass, and even more preferably 2 to 5% by mass, based on the total mass of the liquid detergent (α). When the content of the (B) component is equal to or greater than the above lower limit, good rinsing properties are easily obtained during cleaning treatment after applying the liquid detergent (α) to a textile product and subjecting it to a heat treatment. When the content of the (B) component is equal to or less than the above upper limit, the stability of the liquid detergent (α) is excellent.
In particular, it is preferred that component (B) contains coconut fatty acid or a salt thereof. The total proportion of coconut fatty acid and coconut fatty acid salt relative to the total mass of component (B) is preferably 60 to 100 mass%, more preferably 80 to 100 mass%, and even more preferably 90 to 100 mass%.

<Component (C)>
Component (C) is a water-miscible organic solvent.
In the present invention, the water-miscible organic solvent refers to an organic solvent that dissolves in an amount of 50 g or more in 1 L of ion-exchanged water at 25°C.
Examples of the component (C) include monohydric alcohols having 2 to 4 carbon atoms, polyhydric alcohols having 2 to 4 carbon atoms, glycol ether solvents represented by the following general formula (III), and solvents represented by the following general formula (IV).

R ⁴ -(OR ⁵ ) _y OH...(III)
_CH3OCR6 (CH3 ₎ ^{CHR7CHR8OR9 ... ( IV} )
In formula (III), R ⁴ is an alkyl group having 1 to 6 carbon atoms or a phenyl group, R ⁵ is an alkylene group having 2 to 4 carbon atoms, and y represents the average number of repetitions of OR ⁵ , which is 1 to 5. The number 5.
In formula (IV), R ⁶ to R ⁸ each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R ⁹ represents a hydrogen atom or an acetyl group.

Examples of the monohydric alcohol having 2 to 4 carbon atoms include ethanol, 1-propanol, 2-propanol, and 1-butanol.
Examples of polyhydric alcohols having 2 to 4 carbon atoms include ethylene glycol, propylene glycol, butylene glycol, and glycerin.
Examples of the glycol ether solvent represented by formula (III) include ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, ethylene glycol monophenyl ether (phenoxyethanol), propylene glycol monophenyl ether, diethylene glycol monomethyl ether, and diethylene glycol monobutyl ether.
Examples of the solvent represented by formula (IV) include 3-methoxymethanol, 3-methoxy-3-methyl-1-butanol, butyl carbitol, 3-methoxy-3-ethylbutanol, 3-methoxy-3-propylbutanol, 3-methoxy-2-methylbutanol, 3-methoxy-2-ethylbutanol, 3-methoxy-2-propylbutanol, 3-methoxy-1-methylbutanol, 3-methoxy-1-ethylbutanol, 3-methoxy-1-propylbutanol, 3-methoxybutyl acetate, 3-methoxy-3-methylbutyl acetate, 3-methoxy-3-ethylbutyl acetate, 3-methoxy-3-propylbutyl acetate, 3-methoxy-2-methylbutyl acetate, 3-methoxy-2-ethylbutyl acetate, 3-methoxy-2-propylbutyl acetate, 3-methoxy-1-methylbutyl acetate, 3-methoxy-1-ethylbutyl acetate, and 3-methoxy-1-propylbutyl acetate.

Among these, from the viewpoint of further improving the cleaning power against yellow stains, 3-methoxy-3-methyl-1-butanol, butyl carbitol, and phenoxyethanol are preferred.
In addition, from the viewpoints of being less likely to gel even if the liquid detergent (α) is concentrated when applied to a textile product and heated, and of having excellent rinsing properties, propylene glycol, 3-methoxy-3-methyl-1-butanol, butyl carbitol, and phenoxyethanol are preferred.
Furthermore, from the viewpoint of the fluidity and handling of the liquid detergent (α), ethanol, propylene glycol, 3-methoxy-3-methyl-1-butanol, butyl carbitol, and phenoxyethanol are preferred.

The component (C) may be used alone or in combination of two or more types.
Preferred combinations when two or more types of component (C) are used in combination include combinations of ethanol and propylene glycol, ethanol and 3-methoxy-3-methyl-1-butanol, ethanol and butyl carbitol, and ethanol and phenoxyethanol.
Other preferred combinations include combinations of propylene glycol and 3-methoxy-3-methyl-1-butanol, propylene glycol and butyl carbitol, and propylene glycol and phenoxyethanol.
Other examples of the combination include 3-methoxy-3-methyl-1-butanol and butyl carbitol, 3-methoxy-3-methyl-1-butanol and phenoxyethanol, and butyl carbitol and phenoxyethanol.
Among these combinations, preferred combinations include ethanol and propylene glycol, ethanol and 3-methoxy-3-methyl-1-butanol, ethanol and phenoxyethanol, propylene glycol and 3-methoxy-3-methyl-1-butanol, propylene glycol and butyl carbitol, propylene glycol and phenoxyethanol, 3-methoxy-3-methyl-1-butanol and phenoxyethanol, and butyl carbitol and phenoxyethanol.

The content of component (C) is preferably 4 to 30% by mass, more preferably 5 to 25% by mass, and even more preferably 10 to 20% by mass, based on the total mass of liquid detergent (α). If the content of component (C) is equal to or greater than the lower limit, the cleaning power against yellowing stains and oily stains is superior. The higher the content of component (C), the shorter the time required to exhibit superior cleaning power (the time of heat treatment after application of liquid detergent (α)). In addition, the liquid stability of liquid detergent (α) is superior. In addition, the rinsing property during cleaning treatment after applying liquid detergent (α) to a textile product and subjecting it to heat treatment is superior. If the content of component (C) is equal to or less than the upper limit, costs can be reduced.

The proportion of one or more organic solvents selected from the group consisting of 3-methoxy-3-methyl-1-butanol, butyl carbitol, and phenoxyethanol relative to the total mass of component (C) is preferably 50% by mass or more, more preferably 60% by mass, and particularly preferably 65% by mass. When the proportion of one or more organic solvents selected from the group consisting of 3-methoxy-3-methyl-1-butanol, butyl carbitol, and phenoxyethanol relative to the total mass of component (C) is equal to or greater than the above lower limit, the cleaning power against yellowing stains and oily stains is improved.
In addition, by using one or more organic solvents selected from the group consisting of 3-methoxy-3-methyl-1-butanol, butyl carbitol, and phenoxyethanol in combination with one or more organic solvents selected from the group consisting of ethanol and propylene glycol, a liquid detergent that maintains high detergency against yellowing stains and oily stains and has excellent fluidity can be obtained.
The content of one or more organic solvents selected from the group consisting of ethanol and propylene glycol relative to the total mass of the component (C) is preferably 10 mass% or more, more preferably 20 mass% or more, and is preferably 40 mass% or less, more preferably 30 mass% or less.

<Component (D)>
The component (D) is an anionic surfactant (excluding higher fatty acid salts).
As the anionic surfactant, anionic surfactants conventionally used in liquid detergents for textile products and the like can be used, such as linear alkylbenzene sulfonic acid or a salt thereof; olefin (C10-20) sulfonic acid or a salt thereof (α-olefin sulfonic acid or a salt thereof in which the double bond is located at the 1st position of the carbon chain, internal olefin sulfonic acid or a salt thereof in which the double bond is located inside the carbon chain); linear or branched alkyl sulfate or a salt thereof; polyoxyalkylene alkyl ether sulfate or a salt thereof; polyoxyalkylene alkenyl ether sulfate or a salt thereof; alkane sulfonate having an alkyl group; carboxylic acid type anionic surfactants such as alkyl ether carboxylic acid or its salt, polyoxyalkylene ether carboxylic acid or its salt, alkylamide ether carboxylic acid or its salt, alkenylamide ether carboxylic acid or its salt, and acylamino carboxylic acid or its salt; and phosphate ester type anionic surfactants such as alkyl phosphate ester or its salt, polyoxyalkylene alkyl phosphate ester or its salt, polyoxyalkylene alkylphenyl phosphate ester or its salt, and glycerin fatty acid ester monophosphate ester or its salt.
Examples of the salt form of the anionic surfactant include alkali metal salts such as sodium and potassium; alkaline earth metal salts such as magnesium; and alkanolamine salts such as monoethanolammonium and diethanolammonium.
The component (D) may be used alone or in combination of two or more types.

The content of component (D) relative to the total mass of the liquid detergent (α) is preferably less than 50 mass%, more preferably 5 to 35 mass%, even more preferably 10 to 25 mass%, and particularly preferably 12 to 18 mass%.
When the content of component (A) in the liquid detergent (α) is 30 mass% or less, the content of component (D) is preferably 20 mass% or more, more preferably 25 to 40 mass%, and even more preferably 25 to 35 mass%, based on the total mass of the liquid detergent (α).
When the content of component (A) in the liquid detergent (α) exceeds 30 mass %, the content of component (D) is preferably 5 to 30 mass %, more preferably 10 to 25 mass %, and even more preferably 12 to 20 mass %, based on the total mass of the liquid detergent (α).
When the content of the (D) component is equal to or more than the above lower limit, the cleaning power against yellow stains and oily stains is superior, and when the content is equal to or less than the above upper limit, the stability of the liquid detergent (α) is superior.

The sum of the contents of components (A) and (D) relative to the total mass of liquid detergent (α) is preferably 40 to 80 mass%, more preferably 50 to 75 mass%, and even more preferably 55 to 70 mass%. If the sum of the contents of components (A) and (D) is equal to or greater than the lower limit, the cleaning power is superior, and if it is equal to or less than the upper limit, the liquid stability of liquid detergent (α) is superior.

The mass ratio of the contents represented by the component (A)/the component (D) (A/D ratio) is preferably 0.1-10, more preferably 0.8-5, and even more preferably 1-3.
When the content of component (A) in the liquid detergent (α) exceeds 30% by mass, the A/D ratio is preferably from 1 to 10, more preferably from 1.5 to 5, and even more preferably from 2 to 4. In a composition in which the content of component (A) exceeds 30% by mass, if the A/D ratio is within the above range, the cleaning power for yellowing stains during coating and cleaning is further improved.
When the content of component (A) in the liquid detergent (α) is 30% by mass or less, the A/D ratio is preferably 0.1 to 2, more preferably 0.2 to 1, and even more preferably 0.5 or more and less than 1. In a composition containing component (A) of 30% by mass or less, if the A/D ratio is within the above range, the cleaning power against stubborn stains such as oil stains (especially chili oil stains) is superior. In addition, the fluidity of the liquid detergent (α) is also improved.

<Component (E)>
The component (E) is a cationic surfactant.
Examples of cationic surfactants include long-chain aliphatic amide alkyl tertiary amines or salts thereof, such as caprylic acid dimethylaminopropylamide, capric acid dimethylaminopropylamide, lauric acid dimethylaminopropylamide, myristic acid dimethylaminopropylamide, palmitic acid dimethylaminopropylamide, stearic acid dimethylaminopropylamide, behenic acid dimethylaminopropylamide, and oleic acid dimethylaminopropylamide; aliphatic ester alkyl tertiary amines or salts thereof, such as palmitate ester propyl dimethylamine and stearate ester propyl dimethylamine; palmitic acid diethanolaminopropylamide, stearic acid diethanolaminopropylamide, and the like. Among these, caprylic acid dimethylaminopropylamide, capric acid dimethylaminopropylamide, lauric acid dimethylaminopropylamide, myristic acid dimethylaminopropylamide, palmitic acid dimethylaminopropylamide, stearic acid dimethylaminopropylamide, behenic acid dimethylaminopropylamide, and oleic acid dimethylaminopropylamide or salts thereof are particularly preferred. Mixtures of these are also preferred.
The cationic surfactant may be appropriately selected from known cationic surfactants, such as alkyl trimethyl ammonium salts, dialkyl dimethyl ammonium salts, alkyl benzyl dimethyl ammonium salts, and alkyl pyridinium salts.
The component (E) may be used alone or in combination of two or more types.

The content of component (E) is preferably 1 to 10% by mass, more preferably 1 to 7% by mass, and even more preferably 1 to 5% by mass, relative to the total mass of liquid detergent (α). If the content of component (E) is equal to or greater than the lower limit, the liquid detergent (α) will have excellent antibacterial effect when applied to a textile product and then subjected to a heat treatment, and if the content is equal to or less than the upper limit, the liquid detergent (α) will have excellent stability.

<Amphoteric surfactant>
As the amphoteric surfactant, any amphoteric surfactant that has conventionally been used in liquid detergents for textile products and the like can be used, and examples thereof include amphoteric surfactants such as alkyl betaine type, alkyl amide betaine type, imidazoline type, alkyl amino sulfonic acid type, alkyl amino carboxylic acid type, alkyl amide carboxylic acid type, amide amino acid type, and phosphoric acid type.
The amphoteric surfactant may be used alone or in combination of two or more kinds.

<Water>
The liquid detergent (α) preferably contains water.
The water content is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 20% by mass or more, and particularly preferably 30% by mass or more, based on the total mass of the liquid detergent (α). The water content is preferably less than 50% by mass, and more preferably 40% by mass or less. That is, based on the total mass of the liquid detergent (α), the water content is preferably 5% by mass or more and less than 50% by mass, more preferably 10 to 45% by mass, even more preferably 20 to 40% by mass, and particularly preferably 30 to 40% by mass.
If the water content is within the above range, when the liquid detergent (α) is applied to a textile product and heated, the water evaporates, thereby moderately concentrating the liquid detergent (α) to improve its cleaning power and preventing gelation or solidification due to excessive concentration.

The total content of the component (C) and water is preferably 20 to 50% by mass, more preferably 30 to 45% by mass, based on the total mass of the liquid detergent (α). When the total content of the component (C) and water is within the above range, when the liquid detergent (α) is applied to a textile product and heated, the water and the component (C) volatilize, and the liquid detergent (α) is appropriately concentrated to improve the cleaning power, and gelation or solidification due to excessive concentration can be prevented.
The total content of all components contained in the liquid detergent (α) is 100% by mass.

<Component (F)>
Component (F) is a propylene oxide adduct of a trihydric alcohol (polyoxypropylene glyceryl ether). Component (F) contributes to foam suppression.
The mass average molecular weight of the component (F) is preferably 1,500 to 6,000, more preferably 2,500 to 5,500, and even more preferably 3,000 to 5,000.
The component (F) may be used alone or in combination of two or more types.
The content of component (F) relative to the total mass of the liquid detergent (α) is preferably 0.1 to 5 mass %, more preferably 0.5 to 3 mass %, and even more preferably 0.6 to 2 mass %.

<Optional ingredients>
Examples of optional components include the chelating agents described below, the enzymes described below, the hydrotropes described below (for example, polyethylene glycol, aromatic sulfonic acids or salts thereof, etc.), detergent builders, stabilizers, alkali agents (for example, alkanolamines such as monoethanolamine, diethanolamine, triethanolamine, etc.), texture improvers such as silicone, antibacterial agents (for example, diclosan, triclosan, quaternary ammonium salts such as benzalkonium chloride, etc.), preservatives, fluorescent agents, dye transfer inhibitors, pearling agents, antioxidants, general-purpose dyes or pigments as colorants, emulsifiers, fragrances, pH adjusters, and the like.

(Chelating Agent (Sequestering Agent))
The liquid detergent (α) may contain a chelating agent capable of chelating metal ions.
The chelating agent may be an organic chelating agent. Specific examples of the chelating agent include organic phosphonic acid derivatives such as citric acid, lactic acid, tartaric acid, oxalic acid, malic acid, gluconic acid, nitrilotriacetic acid, iminodiacetic acid, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, glycol ether diaminetetraacetic acid, hydroxyethyliminodiacetic acid, triethylenetetraaminehexaacetic acid, ethane-1,1-diphosphonic acid, ethane-1,1,2-triphosphonic acid, 1-hydroxyethane-1,1-diphosphonic acid, ethanehydroxy-1,1,2-triphosphonic acid, ethane-1,2-dicarboxy-1,2-diphosphonic acid, methanehydroxyphosphonic acid, aminotrimethylenephosphonic acid, and ethylenediaminetetraxymethylenesulfonic acid, or salts thereof. Among these, 1-hydroxyethane-1,1-diphosphonic acid and ethylenediaminetetraxymethylenesulfonic acid are more preferable, and 1-hydroxyethane-1,1-diphosphonic acid is particularly preferable.
The chelating agent may be used alone or in combination of two or more kinds.

(enzyme)
When the liquid detergent (α) contains an enzyme, the detergent has better cleaning power against yellow stains and oily stains.
Examples of the enzyme include protease, amylase, lipase, cellulase, mannanase, cellulase, etc. Here, "enzyme" refers to an enzyme preparation.
The protease is preferably a protease having serine, histidine, and aspartic acid in the molecule, such as a serine protease.
Generally, preparations containing proteases (protease preparations) are commercially available. When preparing liquid detergents, proteases are usually blended using the protease preparations.
Examples of protease preparations include products available from Novozymes under the trade names Savinase 16L, Savinase Ultra 16L, Savinase Ultra 16XL, Everlase 16L TypeEX, Everlase Ultra 16L, Esperase 8L, Alcalase 2.5L, Alcalase Ultra 2.5L, Liquanase 2.5L, Liquanase Ultra 2.5L, Liquanase Ultra 2.5XL, and Coronase 48L; products available from Genencor under the trade names Purafect L and Purafect OX, Properase L, etc.
Examples of amylase preparations include those available from Novozymes under the trade names Termamyl 300L, Termamyl Ultra 300L, Duramyl 300L, Stainzyme 12L, and Stainzyme Plus 12L; those available from Genencor under the trade name Maxamyl; those available from Amano Enzyme Co., Ltd. under the trade name Pullulanase Amano; and those available from Seikagaku Corporation under the trade name DB-250.
Examples of lipase preparations include Lipex 100L and Lipolase 100L available from Novozymes.
Examples of cellulase preparations include Carezyme 4500L (trade name, manufactured by Novozymes), Carezyme Premium 4500L (trade name, manufactured by Novozymes), Endrase 5000L (trade name, manufactured by Novozymes), and Cellclean 4500T (trade name, manufactured by Novozymes).
An example of a mannanase preparation is available from Novozymes under the trade name Mannaway 4L.
The above enzymes may be used alone or in combination of two or more.
The content of the enzyme as an enzyme preparation is preferably 0.1 to 3% by mass based on the total mass of the liquid detergent (α).

(Hydrotrope)
Examples of the hydrotropic agent include paratoluenesulfonic acid or a salt thereof, cumenesulfonic acid or a salt thereof, benzoates, urea, etc. Among these, paratoluenesulfonic acid or a salt thereof, and cumenesulfonic acid or a salt thereof are preferred.
The content of the hydrotrope agent is preferably 0.1 to 10% by mass, more preferably 1 to 8% by mass, and particularly preferably 2 to 5% by mass, based on the total mass of the liquid detergent (α). When the content of the hydrotrope agent is within the above range, the liquid detergent (α) has good fluidity, is excellent in permeability into textile products, and is unlikely to gel even when heated to high temperatures.

<Containerized liquid cleaning agent products>
The liquid detergent (α) is preferably contained in a container and used as a containerized liquid detergent product. All components of the liquid detergent (α) may be contained in a container to form a one-liquid type liquid detergent, or the liquid detergent (α) may be divided into a plurality of liquids (e.g., two liquids) and each liquid may be contained in a container to form a liquid detergent (e.g., a two-liquid type liquid detergent).
The container is preferably one that can directly apply the liquid detergent to the textile product from the discharge port of the container, such as a squeeze container, a trigger container, a container with an application surface for directly applying the liquid to the textile product, etc. The container may be a reusable container or a disposable container.

<Method for producing liquid detergent (α)>
The liquid detergent (α) can be produced according to a conventional method for producing a liquid detergent. For example, the (A) component and, if necessary, components other than the (A) component (excluding the pH adjuster) are added to a portion of the water serving as a dispersion medium, and mixed. If necessary, a pH adjuster is added to adjust the pH, and the remainder of the water is added to make the total amount 100% by mass to produce the liquid detergent (α). It is preferable to further put the mixture in a container to produce a containerized liquid detergent product.
In the case of a two-liquid type liquid detergent, a first liquid and a second liquid are prepared by mixing the components to be contained in each liquid, and then each liquid is placed in a container to prepare a container-packed liquid detergent. The container for storing the first liquid and the container for storing the second liquid may be separate or may be integrated.

"Washing method"
The method for washing textile products of the present invention is a method in which the above-mentioned liquid detergent (α) is applied to a textile product (item to be washed), which is then heated at 20 to 70°C, and then the textile product is brought into contact with water for a washing treatment. After the washing treatment, a rinsing treatment is preferably carried out. Hereinafter, in this specification, the washing treatment and the rinsing treatment are collectively referred to as "washing treatment".
When applying the liquid detergent (α) to a textile product, it is preferable to apply the liquid detergent (α) to the stain on the textile product. By applying the liquid detergent (α) to the stain on the textile product, the stained portion of the textile product is impregnated with the liquid detergent (α) and the stain is brought into contact with the liquid detergent (α).
When applying the liquid detergent (α) to a textile product, it is preferable to bring the liquid detergent (α) into contact with the stain while maintaining its concentration, and therefore it is preferable to apply the liquid detergent (α) directly to the stain without immersing the textile product in water.
When using a two-liquid type liquid detergent, the first liquid, the second liquid, and the textile product are applied to the stains on the textile product so that they come into contact with each other.

It is preferable to apply an amount of liquid detergent (α) that is sufficient to penetrate the entire stained area.

The temperature (heat treatment temperature) when the textile product coated with the liquid detergent (α) is heat treated is 20 to 70°C, preferably 30 to 70°C, more preferably 40 to 60°C, and even more preferably 40 to 45°C. If the heat treatment temperature is equal to or higher than the lower limit, the liquid detergent (α) is concentrated on the textile in a short time, i.e., the volatile components in the liquid detergent (α) volatilize in a short time, so that the textile product can be washed efficiently and the time burden can be reduced. If the liquid detergent (α) is concentrated on the textile product, its compatibility with the stains attached to the textile product increases, and excellent cleaning power is exerted against stains such as yellowing stains and oil stains. If the heat treatment temperature is equal to or lower than the upper limit, the progression of yellowing can be suppressed, and sufficient cleaning power against yellowing stains can be obtained. In addition, when protein stains are attached to the textile product, protein denaturation is unlikely to occur, and sufficient cleaning power can be obtained against protein stains due to sebum, food spills, blood, etc.

The time (heat treatment time) for heat treating the textile product coated with the liquid detergent (α) is preferably 5 to 120 minutes, more preferably 30 to 100 minutes, and even more preferably 45 to 75 minutes. If the heat treatment time is equal to or more than the above lower limit, the cleaning power against stubborn stains such as oil stains (especially chili oil stains) is more excellent. If the heat treatment time is equal to or less than the above upper limit, the progression of yellowing can be further suppressed, and the cleaning power against yellowing stains is more excellent.
When the heat treatment temperature is 20 to 50° C., the heat treatment time is preferably 60 to 100 minutes. When the heat treatment temperature is higher than 50° C. and equal to or lower than 70° C., the heat treatment time is preferably 10 to 30 minutes.

The method of heat-treating the textile product coated with the liquid detergent (α) is not particularly limited, but may be, for example, a method in which a washing machine equipped with a device capable of supplying hot air or steam to a washing tub is used, the textile product coated with the liquid detergent (α) is placed in the washing tub, and hot air or steam at a predetermined temperature is supplied to the washing tub. In addition, for example, hot air may be applied to the textile product coated with the liquid detergent (α) using a dryer or the like. In a treatment at a relatively low temperature (for example, 20 to 40°C), the same level of cleaning power as that obtained by treatment under heating conditions above 50°C can be obtained by blowing air using a dryer or the like. The amount of air blown is preferably 0.1 to 2 m ³ /min, more preferably 0.5 to 1.8 m ³ /min, and even more preferably 0.7 to 1.6 m ³ /min. If the amount of air blown is equal to or greater than the lower limit, the heating efficiency can be improved. If the amount of air blown is equal to or less than the upper limit, the progression of yellowing can be suppressed, and the cleaning power against yellowing stains is more excellent.

The method of the washing treatment is not particularly limited as long as the textile product after being coated with the liquid detergent (α) and subjected to a heat treatment is brought into contact with at least water, and dirt adhering to the textile product and the liquid detergent (α) are transferred into the water and removed. A typical washing treatment includes a washing treatment and a rinsing treatment. The rinsing treatment is a treatment for removing the liquid detergent (α) remaining on the textile product after the washing treatment. After the rinsing treatment, the textile product is dried or the like to remove moisture therefrom.
In the cleaning treatment, an external force is preferably applied to the textile product in a cleaning solution containing water and a liquid cleaning agent (α) to transfer the dirt into the cleaning solution, and then the textile product is separated from the cleaning solution by dehydration or the like.
In the rinsing process, after the cleaning process, an external force is preferably applied to the textile product in rinsing water not containing the liquid detergent (α) to transfer the liquid detergent (α) remaining in the textile product into the rinsing water, and then the textile product is separated from the rinsing water by dehydration or the like.
The washing step is usually carried out once. The rinsing step may be carried out once or may be repeated two or more times. If the rinsing step is carried out once, the amount of rinsing water used can be reduced and the washing time can be shortened, which is preferable.
The method of applying an external force to the textile product may be, for example, a method of applying mechanical force using a washing machine, or a method of hand washing such as rubbing, pressing, beating, grabbing, pinching, or shaking.

At the start of the cleaning process, the textile product may be contacted with water alone, or with a cleaning liquid containing water and a new cleaning agent (β). When the textile product is contacted with water alone, the liquid cleaning agent (α) applied to the textile product is dispersed in the water to form a cleaning liquid. When the textile product is contacted with water and a cleaning liquid containing a cleaning agent (β), the liquid cleaning agent (α) applied to the textile product is dispersed in the cleaning liquid, and the concentration of the cleaning agent components in the cleaning liquid increases.
The detergent (β) may be liquid or powder. There is no particular limitation on the detergent (β), and a known detergent for textile products can be used. In addition, the detergent (β) may be a liquid detergent (α) or a commercially available product. In particular, the detergent (β) is preferably a detergent containing polyoxyethylene fatty acid methyl ester (MEE) and polyoxyethylene alkyl ether (AE).

The textile products in the washing process may include not only textile products to which the liquid detergent (α) has been applied, but also other textile products to which the liquid detergent (α) has not been applied.
The amount of detergent used in the cleaning treatment is preferably such that the ratio of the total mass of the textile product (mass of fabric)/the total mass of the detergent (total mass of the liquid detergent (α) and the detergent (β)) is 10 to 500, more preferably 10 to 300, and even more preferably 10 to 100. When the ratio is equal to or more than the lower limit, the detergent has excellent rinsing properties when applied for a long period of time, and when the ratio is equal to or less than the upper limit, the detergent has excellent detergency for other textile products to which the liquid detergent (α) is not applied.
When a liquid detergent (α) is used as the detergent (β), all of the liquid detergent (α) used in the cleaning process may be used to apply to the stains on the textile product, or a portion of the liquid detergent (α) may be applied to the stains on the textile product and the remainder may be added during the cleaning process.
The amount of water used in the cleaning treatment is preferably 30 times or more, more preferably 30 to 500 times, and more preferably 30 to 300 times, the amount of the cleaning agent used in the cleaning treatment (the total mass of the liquid cleaning agent (α) and cleaning agent (β)). When the amount of water used in the cleaning treatment is equal to or more than the above lower limit, the rinsing property is superior, and when the amount of water used in the cleaning treatment is equal to or less than the above upper limit, the cleaning performance is superior.

According to the washing method of the present invention, a specific liquid detergent is applied to stains adhering to textile products, and then a washing process is performed after heating at a specific temperature. This provides excellent washing power, particularly against yellowing stains and oily stains. Furthermore, by heating the textile product to which the liquid detergent has been applied before the washing process, the liquid detergent (α) is concentrated on the fibers in a short time, shortening the washing time and reducing the time burden.

Examples of textile products include clothing, dish towels, sheets, curtains, pillowcases, etc. The material of the textile products is not particularly limited, and may be any of natural fibers such as cotton, silk, wool, etc., and chemical fibers such as polyester, polyamide, etc.
The washing method of the present invention is preferably applied to stains that are difficult to remove by conventional washing methods, particularly yellowing stains and oil stains. In addition to yellowing stains and oil stains, the washing method of the present invention is also suitable for removing stains such as ink, foundation, lipstick, sebum, solid fats, food spills (curry, ketchup, sauce), and blood. Among these, the washing method of the present invention shows good cleaning power for yellowing stains, oil stains, and food spills that are a mixture of oil stains and protein stains.

The present invention will be described in detail below with reference to examples, but the present invention is not limited to the following description.
The following Examples 1, 2, and 6 to 12 are working examples, and Examples 3 to 5 are comparative examples.

"Ingredients used"
The compounds used as the respective components are shown below.
<Component (A)>
A-1 (MEE): fatty acid methyl ester ethoxylate (fatty acid carbon number 12 to 14, average number of moles of EO added 15), in the above general formula (I), R ¹ = alkyl group having 11 carbon atoms and alkyl group having 13 carbon atoms, R ² = methyl group, s = 15, t = 0, u = 0. Synthesized by the following synthesis method. Narrow ratio 30 mass%.
A-2 (MEE): fatty acid methyl ester ethoxylate (fatty acid carbon number: 18, average number of moles of EO added: 15), in the above general formula (I), R ¹ = alkyl group and alkenyl group having 17 carbon atoms, R ² = methyl group, s = 15, t = 0, u = 0. Narrow ratio: 60% by mass.
A-3 (AE(15EO)): A product in which 15 moles of ethylene oxide have been added to natural alcohol. In the above general formula (II), R ³ = an alkyl group having 12 carbon atoms and an alkyl group having 14 carbon atoms, v = 15, w = 0, x = 0. Synthesized by the following synthesis method.

<Component (B)>
B-1: Coconut fatty acid, manufactured by NOF Corporation, trade name "Coconut Fatty Acid".
B-2: Palmitic acid, manufactured by NOF Corporation, trade name "NAA-160".

<Component (C)>
C-1: 3-Methoxy-3-methyl-1-butanol, manufactured by Kuraray Co., Ltd., trade name "Solfit (fine grade)".
C-2: Ethanol, manufactured by Japan Alcohol Sales Co., Ltd., product name "Specific Alcohol 95% Synthetic".

<Component (D)>
D-1: Linear alkylbenzene sulfonic acid (LAS), (manufactured by Lion Corporation, trade name "Lipon LH-200").
D-2: Polyoxyalkylene alkyl ether sulfate (AES), (a mixture of sodium polyoxyethylene lauryl ether sulfate and sodium polyoxyethylene myristyl ether sulfate, average number of moles of EO added: 1).
D-3: Sodium C14-α olefin sulfonate (AOS) (manufactured by Lion Corporation, trade name "Lipolan LJ441"). Note that the "C" in "C14" refers to the number of carbon atoms.

<Water>
- Purified water: Manufactured by Kanto Chemical Co., Ltd.

<Optional ingredients>
Cumene sulfonic acid: manufactured by Teika Corporation, trade name "Teikatox N5040".
- Paratoluenesulfonic acid: product name "PTS acid", manufactured by Kyowa Hakko Kirin Co., Ltd.
Sodium lactate: manufactured by Kanto Chemical Co., Ltd., product name "Sodium lactate".
MGDA: trisodium methylglycine diacetate, manufactured by BASF, trade name "Trilon M Liquid".
- Calcium chloride: Product name "Calcium chloride" manufactured by Kanto Chemical Co., Ltd.
Sodium benzoate: manufactured by Toagosei Co., Ltd., trade name "Sodium Benzoate".
Fragrance: Fragrance composition A described in Tables 11 to 18 of JP-A No. 2002-146399.
Soil release polymer: Clariant Japan Co., Ltd., product name "TexCare SRN-170C", mass average molecular weight = 2000 to 3000, pH (5 mass% aqueous solution at 20 ° C.) = 4, viscosity (20 ° C.) = 300 mPa · s. TexCare SRN-170C is a 70 mass% aqueous solution of product name: TexCare SRN-100 (Clariant Japan Co., Ltd., mass average molecular weight: 2000 to 3000).
HP-20: Ethylene oxide adduct of polyethyleneimine, manufactured by BASF, trade name "Sokalan HP20".
Sodium hydroxide: manufactured by Tsurumi Soda Co., Ltd., trade name "Sodium Hydroxide".
- Alcalase: A protease preparation manufactured by Novozymes, trade name "Alcalase 2.5L".
- Colorant: manufactured by Kishi Chemical Co., Ltd., product name "Green No. 3".
- Monoethanolamine: Manufactured by Nippon Shokubai Co., Ltd., product name "Monoethanolamine".

Synthesis of MEE
It was synthesized according to the synthesis method described in JP-A-2000-144179.
Alumina magnesium hydroxide (manufactured by _Kyowa Chemical Industry Co., Ltd., trade name "Kyoward ₃₀₀ ") having a composition of _{2.5MgO.Al2O3.zH2O} was calcined at 600°C for 1 hour under a nitrogen atmosphere to obtain a calcined alumina magnesium hydroxide (unmodified) catalyst. 2.2g of the calcined alumina magnesium hydroxide (unmodified) catalyst, 2.9mL of 0.5N potassium hydroxide ethanol solution, 280g of lauric acid methyl ester, and 70g of myristic acid methyl ester were charged into a 4L autoclave, and the catalyst was modified in the autoclave. Next, after replacing the inside of the autoclave with nitrogen, 1052g of ethylene oxide was introduced while maintaining the temperature at 180°C and the pressure at 0.3MPa, and reacted with stirring.
The resulting reaction liquid was cooled to 80° C., and 159 g of water and 5 g each of activated clay and diatomaceous earth as filter aids were added and mixed, after which the catalyst was filtered off to obtain MEE.

<Synthesis of AE(15EO)>
224.4 g of CO-1214 (trade name) manufactured by Procter & Gamble Co. and 2.0 g of a 30% by mass NaOH aqueous solution were charged into a pressure-resistant reaction vessel, and the inside of the reaction vessel was replaced with nitrogen. Next, the reaction vessel was dehydrated for 30 minutes at a temperature of 100°C and a pressure of 2.0 kPa or less, and then the temperature was raised to 160°C. Next, 760.6 g of ethylene oxide (gaseous) was gradually added to the reaction liquid while stirring the reaction liquid. At this time, ethylene oxide was added through a blowing tube while adjusting the addition rate so that the reaction temperature did not exceed 180°C. After the addition of ethylene oxide was completed, the mixture was aged for 30 minutes at a temperature of 180°C and a pressure of 0.3 MPa or less, and then unreacted ethylene oxide was distilled off for 10 minutes at a temperature of 180°C and a pressure of 6.0 kPa or less.
Next, after cooling to a temperature of 100° C. or less, the reaction product was neutralized by adding 70% by mass p-toluenesulfonic acid so that a 1% by mass aqueous solution of the reaction product had a pH of about 7, thereby obtaining AE(15EO).

"Examples 1 to 12"
Liquid detergents were prepared according to the formulations shown in Tables 1 to 3, and textile products were washed under the conditions (heat treatment temperature and heat treatment time) shown in Tables 1 to 3. The cleaning power against yellowing stains and oily stains was evaluated by the following method. The results are shown in Tables 1 to 3.
The liquid detergent was produced by adding the components (A) to (D) and any optional components to water according to the formulation in the table and mixing them.
The table shows the following values of a to f for each example of the liquid detergent.
a: mass ratio of component (A)/component (B), b: mass ratio of component (A)/component (D), c: total content of component (A), d: total content of component (D), e: total content of surfactants, f: content of component (C).
The content in the table is in mass% and is expressed as a pure amount. A blank space in the table means that the component is not blended.

"Evaluation Method"
<Evaluation 1: Evaluation of cleaning power against yellow stains>
(Creating yellow stained cloth)
A cotton cloth cut to a size of 5 cm x 5 cm was prepared as the evaluation cloth.
In addition, squalene was prepared as a yellowing component.
Squalene dissolved in a solvent (toluene) was added to the fabric for evaluation to a concentration of 5.0% owf, and the fabric was left to dry at room temperature to obtain a yellowed stained fabric. owf is an abbreviation for On the Weight Fabric, and is a value calculated by the amount of stain/weight of fabric×100(%).
The yellow stained cloth was washed in the following manner: Washing 1 was a standard washing method for evaluating the cleaning power against yellow stains.

(Washing 1: Leave for 12 hours after application)
10 g of liquid detergent was applied to four pieces of yellowed stained cloth so that the yellowed stain attached to the yellowed stained cloth was in the center, and after leaving it at 25°C for 12 hours, it was washed by the method described below to remove the stains.
Four pieces of the yellowed stained cloth after standing were placed in a fully automatic drum washing machine (Hitachi Global Life Solutions, Inc., product name "BD-NX120C"), and a charge cloth (knitted cloth cut into small pieces, thoroughly washed, rinsed, and dried) was further added so that the total weight of the washed items was 2 kg. The washing process was repeated once using a standard cycle with a bath ratio of 20 times, washing for 12 minutes, rinsing once, and spin-drying for 6 minutes, and then air-dried. The bath ratio is the ratio (unit: times) of washing liquid (unit: L)/washed items (unit: kg).
The reflectance (R) of each of the evaluation cloths without yellowing stains, the yellowing stained cloths before cleaning (before washing), and the yellowing stained cloths after cleaning (after washing) was measured using a color difference meter (manufactured by Nippon Denshoku Industries Co., Ltd., product name "SE200 type"), and the cleaning rate (%) was calculated from the following formula (i). The cleaning rate (%) was calculated for each of the four yellowing stained cloths, and the average value was calculated.
Cleaning rate (%)=100×(K/S of soiled cloth before cleaning−K/S of soiled cloth after cleaning)/(K/S of soiled cloth before cleaning−K/S of evaluation cloth)×100 (i)
Here, K/S is a value calculated by the formula: (1-R/100) ² /(2R/100), and R is the reflectance (%) of the evaluation cloth, the soiled cloth before washing, or the soiled cloth after washing.

(Washing 2: After application, heat treatment)
10 g of the liquid detergent was applied to four pieces of yellow-stained cloth so that the yellow-stain attached to the yellow-stained cloth was in the center.
Four pieces of the yellowed stained cloth after standing were placed in a fully automatic drum washing machine (manufactured by Hitachi Global Life Solutions, Inc., product name "BD-NX120C"), and a charge cloth (a knitted cloth cut into small pieces, thoroughly washed, rinsed, and dried) was further added so that the total weight of the washed items was 2 kg, and heat treatment was performed under the conditions (heat treatment temperature and heat treatment time) shown in Tables 1 to 3. The concentration rate of the liquid detergent on the yellowed stained cloth after heat treatment is shown in Tables 1 to 3.
Thereafter, the laundry was washed once using a standard cycle with a bath ratio of 20 times, washing for 12 minutes, rinsing once, and spin-drying for 6 minutes, and then air-dried.
The concentration rate of the liquid detergent was calculated using the following formula (ii).
Concentration rate (%)=100×(weight (g) of the yellow-stained cloth to which 10 g of liquid detergent has been attached before heat treatment−weight (g) of the yellow-stained cloth after heat treatment)/10 (g) (ii)

The reflectance (R) of each of the evaluation cloths without yellowing stains, the yellowing stained cloths before cleaning (before washing), and the yellowing stained cloths after cleaning (after washing) was measured using a color difference meter (manufactured by Nippon Denshoku Industries Co., Ltd., product name "SE200 type"), and the cleaning rate (%) was calculated using the above formula (i). The cleaning rate (%) was calculated for each of the four yellowing stained cloths, and the average value was calculated.

(evaluation)
The cleaning power for yellow stains was evaluated based on the following evaluation criteria.
A: The cleaning rate (average value) of wash 2 is higher than the cleaning rate (average value) of wash 1 (the difference in cleaning rate is 5% or more).
B: The cleaning rate (average value) of wash 2 is higher than the cleaning rate (average value) of wash 1 (the difference in cleaning rate is more than 0% and less than 5%).
C: The cleaning rate (average value) of wash 2 is lower than the cleaning rate (average value) of wash 1.

<Evaluation 2: Evaluation of cleaning power against oily stains>
(Creating oil-stained cloth)
A cotton cloth cut to a size of 5 cm x 5 cm was prepared as the evaluation cloth.
In addition, chili oil (manufactured by S&B Foods Co., Ltd.) was prepared as an oil stain.
Two drops of chili oil were dropped onto the evaluation cloth, which was then left to stand at room temperature and dried to prepare an oil-stained cloth.
The oil-stained cloth was washed in the following manner: Washing 3 described below is a standard washing method for evaluating the cleaning power against oil stains.

(Washing 3: Leave for 12 hours after application)
10 g of the liquid detergent was applied to four pieces of oil-stained cloth so that the oil stains on the oil-stained cloth were the center, and the cloth was left for 12 hours at 25° C. Thereafter, the cloth was washed in the same manner as in Washing 1 of Evaluation 1 to wash away the stains.
The reflectance (R) of each of the evaluation cloths not stained with oil, the oil-stained cloths before cleaning (before washing), and the oil-stained cloths after cleaning (after washing) was measured using a color difference meter (manufactured by Nippon Denshoku Industries Co., Ltd., product name "SE200 type"), and the cleaning rate (%) was calculated using the above formula (i). The cleaning rate (%) of each of the four oil-stained cloths was calculated, and the average value was calculated.

(Washing 4: After application, heat treatment)
10 g of the liquid detergent was applied to four pieces of oil-stained cloth so that the oil stains on the cloth were the center. Then, the cloth was heated and washed in the same manner as in Washing 2 of Evaluation 1 to wash the stains.
The reflectance (R) of each of the evaluation cloths not stained with oil, the oil-stained cloths before cleaning (before washing), and the oil-stained cloths after cleaning (after washing) was measured using a color difference meter (manufactured by Nippon Denshoku Industries Co., Ltd., product name "SE200 type"), and the cleaning rate (%) was calculated using the above formula (i). The cleaning rate (%) of each of the four oil-stained cloths was calculated, and the average value was calculated.

(evaluation)
The cleaning power against oily stains was evaluated based on the following evaluation criteria.
A: The cleaning rate (average value) of wash 4 is higher than the cleaning rate (average value) of wash 3 (the difference in cleaning rate is 5% or more).
B: The cleaning rate (average value) of wash 4 is higher than the cleaning rate (average value) of wash 3 (the difference in cleaning rate is more than 0% and less than 5%).
C: The cleaning rate (average value) of wash 4 is lower than the cleaning rate (average value) of wash 3.

From the results in Tables 1 to 3, Examples 1, 2, and 6 to 12 exhibited good cleaning power against yellowing stains and oily stains. Moreover, compared with the case where the liquid detergent was applied to the evaluation cloth and then left for 12 hours (washing 1 and 3), washing could be completed in a short time by applying the liquid detergent to the evaluation cloth and then subjecting it to heat treatment at a specified temperature (washing 2 and 4).
On the other hand, in the case of Example 3 in which the heat treatment temperature was more than 70° C., the cleaning power against yellowing stains was insufficient.
In the case of Example 4, in which the heat treatment temperature was less than 20° C., the cleaning power against yellowing stains and oily stains was insufficient.
In the case of Example 5, in which a liquid detergent containing no nonionic surfactant was used, the cleaning power against yellow stains and oily stains was insufficient.

Claims (3)

A method for washing textile products, comprising the steps of applying a liquid detergent containing a surfactant (excluding higher fatty acid salts) including a nonionic surfactant (A) to the textile products, subjecting the textile products to a heat treatment at 30 to 70°C, and then contacting the textile products with water to perform a washing treatment,
The total content of the surfactant is 40% by mass or more based on the total mass of the liquid detergent,
The method for washing textile products, wherein the heat treatment time is 20 to 100 minutes . The method for washing textile products according to claim 1 , wherein the liquid detergent further contains a water-miscible organic solvent (C). The method for washing textile products according to claim 1 or 2, wherein the liquid detergent further contains an anionic surfactant (D).