JP7475216B2 - Liquid cleaning composition - Google Patents

Description

The present invention relates to a liquid detergent composition.

2. Description of the Related Art Liquid detergent compositions for textile products such as clothing conventionally contain surfactants such as nonionic surfactants.
In recent years, there has been a demand for highly concentrated liquid detergent compositions with high surfactant concentrations so that a small amount of the liquid detergent composition can provide sufficient cleaning effects. In addition, enzymes are often blended to supplement the cleaning power of the surfactant.
Such highly concentrated liquid detergent compositions can be prone to gelling, and a solvent is often added to the compositions in order to inhibit gelling (Patent Document 1).

International Publication No. WO 2014/109380

However, in a highly concentrated liquid detergent composition, simply increasing the amount of solvent used may result in denaturation of the enzyme by the solvent.
In addition, since highly concentrated liquid detergent compositions have a low water content in their composition, if the amount of solvent added is increased, the water content will decrease further, and there is a risk that the incorporated enzymes will be prone to precipitation when stored at low temperatures.
These are particular problems when the amount of enzymes incorporated is increased in highly concentrated liquid detergent compositions.
Therefore, an object of the present invention is to provide a highly concentrated liquid detergent composition in which the enzyme is unlikely to precipitate and is unlikely to denature even when stored at low temperature.

In order to achieve the above object, the present invention employs the following configuration.
[1] Component (A): a nonionic surfactant,
Component (B): a non-soap anionic surfactant;
(D) component: Protease;
Component (C): A liquid detergent composition which may contain an organic solvent having a hydroxyl group,
The content of the component (A) is 35 to 50% by mass based on the total mass of the liquid detergent composition,
The content of the (B) component is 15 to 30% by mass based on the total mass of the liquid detergent composition,
The content of the (C) component is 3 mass% or less based on the total mass of the liquid detergent composition,
The content of the (D) component is 2 to 5% by mass based on the total mass of the liquid detergent composition,
The total content of the (A) component and the (B) component is 50 to 70% by mass based on the total mass of the liquid detergent composition,
The liquid detergent composition, wherein the component (A) contains the following component (A1):
Component (A1): a polyoxyalkylene-type nonionic surfactant represented by the following general formula (a-1):
R ¹ -X-[(EO) _s /(AO) _t ]-(EO) _u -R ² ... (a-1)
In formula (a-1), R ¹ is a hydrocarbon group having 8 to 22 carbon atoms, -X- is a divalent linking group, and R ² is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkenyl group having 2 to 6 carbon atoms.
EO is an oxyethylene group, and s is a number from 3 to 25 indicating the average number of EO repeats.
AO is at least one of PO (oxypropylene group) and BO (oxybutylene group), t indicates the average number of repetitions of AO and is a number from 0 to 6. u indicates the average number of repetitions of EO and is a number from 0 to 20.
When t is 1 or more, the order of EO and AO in [(EO) _s /(AO) _t ] is not limited except that the terminal is not EO, and the polymer may be randomly polymerized or block polymerized. In the case of block polymerization, three or more blocks may be arranged.
However, this does not include the cases where R ¹ is a straight-chain hydrocarbon group, -X- is -O-, the carbon atom of R ¹ to which X is bonded is a primary carbon atom, R ² is a hydrogen atom, and t is 0.
[2] The liquid detergent composition according to [1], wherein the ratio of the mass of the (A) component to the mass of the (B) component [(A)/(B)] is 1.5 to 2.5.
[3] The liquid detergent composition according to [1] or [2], wherein the ratio of the mass of the component (C) to the total mass of the component (A) and the component (B) [(C)/{(A)+(B)}] is 0 to 0.07.
[4] The liquid detergent composition according to any one of [1] to [3], wherein the component (B) comprises one or more components selected from the group consisting of the following component (B1), the following component (B2), the following component (B3), and the following component (B4).
Component (B1): linear alkylbenzene sulfonic acid or a salt thereof.
Component (B2): polyoxyalkylene alkyl(alkenyl) ether sulfate or a salt thereof.
Component (B3): α-olefin sulfonic acid or a salt thereof.
Component (B4): internal olefin sulfonic acid or its salt.

The liquid detergent composition of the present invention has a high surfactant concentration and is highly concentrated, but even when stored at low temperatures, the protease is not easily precipitated and is not easily denatured.

The liquid detergent composition of the present invention is a liquid detergent composition containing components (A), (B), and (D) described below, and may also contain component (C).
The following description of the constituent elements may be based on representative embodiments or specific examples, but the present invention is not limited to such embodiments. In this specification, a numerical range expressed using "to" means a range including the numerical values before and after "to" as the lower and upper limits. In addition, the content of a component that can be in the form of an acid or a salt is the content in the form of an acid, unless otherwise specified.

<Component (A)>
Component (A) is a nonionic surfactant.
The component (A) includes the following component (A1).
The component (A1) is a compound represented by the following general formula (a-1) (hereinafter referred to as compound (a-1)).
R ¹ -X-[(EO) _s /(AO) _t ]-(EO) _u -R ² ... (a-1)

In formula (a-1), R ¹ is a hydrocarbon group having 8 to 22 carbon atoms, -X- is a divalent linking group, and R ² is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkenyl group having 2 to 6 carbon atoms.
EO is an oxyethylene group, and s is a number from 3 to 25 indicating the average number of EO repeats.
AO is at least one of PO (oxypropylene group) and BO (oxybutylene group), t indicates the average number of repetitions of AO and is a number from 0 to 6. u indicates the average number of repetitions of EO and is a number from 0 to 20.
When t is 1 or more, the order of EO and AO in [(EO) _s /(AO) _t ] is not limited except that the terminal is not EO, and the polymer may be randomly polymerized or block polymerized. In the case of block polymerization, three or more blocks may be arranged.

However, this does not include the cases where R ¹ is a straight-chain hydrocarbon group, -X- is -O-, the carbon atom of R ¹ to which X is bonded is a primary carbon atom, R ² is a hydrogen atom, and t is 0.
Hereinafter, a compound in which "R ¹ is a straight-chain hydrocarbon group, -X- is -O-, the carbon atom of R ¹ to which X is bonded is a primary carbon atom, R ² is a hydrogen atom, t is 0, and s + u is 3 to 25" in formula (a-1) may be referred to as "component (AX)".

In formula (a-1), the number of carbon atoms in the hydrocarbon group of R ¹ is 8 to 22, preferably 10 to 18, and more preferably 12 to 18. The hydrocarbon group may be linear or branched. In addition, it may or may not have an unsaturated bond.
^R1 is preferably a straight or branched chain alkyl group.

Examples of the divalent linking group -X- include -O-, -COO-, -CONH-, etc. The carbon atom in ^R1 to which X is bonded may be a primary carbon atom or a secondary carbon atom.
When ^R2 is an alkyl group, it has 1 to 6 carbon atoms, and preferably 1 to 3 carbon atoms. When ^R2 is an alkenyl group, it has 2 to 6 carbon atoms, and preferably 2 to 3 carbon atoms.

s is 3 to 25, preferably 5 to 20, and more preferably 7 to 18. When the average number of EO repeats s is 25 or less, the HLB value does not become too high, which is advantageous for cleaning sebum, and the cleaning function is more easily exhibited. When s is 3 or more, the cleaning effect against sebum stains is easily exhibited.
t is an integer of 0 to 6, and preferably an integer of 0 to 3. When t is 6 or less, the storage stability of the liquid detergent composition at high temperatures is further improved.
u is an integer of 0 to 20, preferably 0 to 15, and more preferably 0 to 10.

s + u, i.e., the average total number of EO moles added in compound (a-1), is 3 to 25, preferably 7 to 25, and more preferably 10 to 20. When s + u is 3 or more, the cleaning effect against sebum stains is easily exhibited. When s + u is 25 or less, the enzyme is less likely to precipitate when the liquid detergent composition is stored at high temperatures. The above range is more preferable, especially when t is 0.

When t is not 0, that is, when the compound (a-1) has EO and PO, EO and BO, or EO, PO and BO, the distribution (arrangement order) of EO and PO, EO and BO, or EO, PO and BO is not particularly limited, and they may be arranged in a block shape or a random shape. In the case of block polymerization, three or more blocks may be arranged. Also, a combination of a random arrangement and a block arrangement may be used.
Examples of the method for arranging EO and PO in a block form include a method of introducing ethylene oxide and then propylene oxide, a method of introducing propylene oxide and then ethylene oxide, and a method of introducing ethylene oxide, then propylene oxide, and further introducing ethylene oxide.
Examples of the method for arranging EO and BO in a block form include a method of introducing ethylene oxide and then butylene oxide, a method of introducing butylene oxide and then ethylene oxide, and a method of introducing ethylene oxide, then butylene oxide, and then ethylene oxide.

The compound (a-1) in which --X-- is --O-- can be obtained by adding ethylene oxide or ethylene oxide and propylene oxide to a primary alcohol or a secondary alcohol (R ¹ --OH).
The compound (a-1) in which -X- is -COO- can be obtained from a fatty acid (R ¹ -COOH) as a raw material. The compound (a-1) in which -X- is -CONH- can be obtained from a fatty acid amide (R ¹ -CONH) as a raw material.

The component (A1) preferably contains one or more components selected from the group consisting of the following components (A11), (A12), (A13), and (A14).
Component (A11): A compound represented by the above general formula (a-1), in which R ¹ is a straight-chain alkyl group, -X- is -O-, s is 3 to 25, t is 1 to 6, u is 0 to 20, R ² is a hydrogen atom, and the carbon atom of R ¹ to which X is bonded is a primary carbon atom.
Component (A12): A compound represented by the above formula (a-1), in which R ¹ is a straight-chain alkyl group, -X- is -O-, s is 3 to 25, t is 0 to 6, u is 0 to 20, R ² is a hydrogen atom, and the carbon atom of R ¹ to which X is bonded is a secondary carbon atom.
Component (A13): A compound in which, in the compound (a-1), R ¹ is a linear alkyl group or a linear alkenyl group, -X- is -COO-, s is 3 to 25, t is 0 to 6, u is 0 to 20, R ² is an alkyl group, and the carbon atom of R ¹ to which X is bonded is a secondary carbon atom.
Component (A14): A compound represented by general formula (a-1), in which R ¹ is a branched alkyl group, -X- is -O-, s is 3 to 25, t is 0 to 6, u is 0 to 20, R ² is a hydrogen atom, and the carbon atom of R ¹ to which X is bonded is a primary carbon atom.

The number of carbon atoms in R ¹ of component (A11) is 8 to 22, preferably 10 to 18, and more preferably 12 to 18. s is 3 to 25, and preferably 5 to 20. t is 1 to 6, and preferably 1 to 3. u is 0 to 20, and preferably 0 to 10. s+u is preferably 3 to 25, more preferably 7 to 25, and even more preferably 10 to 20.

Of the components (A11), a compound obtained by randomly polymerizing EO and PO, or a compound obtained by block polymerizing EO, PO, and EO in this order is preferred.
An example of a compound obtained by randomly polymerizing EO and PO is a compound obtained by randomly adding an average of 20 moles of EO and an average of 2 moles of PO to 1 mole of natural alcohol (mass ratio of alcohol having 12 carbon atoms/alcohol having 14 carbon atoms=7/3).
An example of a compound in which EO, PO, and EO are block polymerized in this order is one in which 8 moles of ethylene oxide, 2 moles of propylene oxide, and 8 moles of ethylene oxide are block-polymerized in this order to 1 mole of natural alcohol (mass ratio of alcohol having 12 carbon atoms/alcohol having 14 carbon atoms=7/3).

The number of carbon atoms in R ¹ of the component (A12) is 8 to 22, preferably 10 to 18, and more preferably 12 to 18. s is 3 to 25, and preferably 5 to 18. t is 0 to 6, and preferably 0 to 3. u is 0 to 20, and preferably 0 to 10.
Commercially available products of the component (A12) include those manufactured by Nippon Shokubai Co., Ltd. under the trade names “SOFTANOL 30”, “SOFTANOL 70”, “SOFTANOL 120”, and “SOFTANOL 150”.

R ¹ in the component (A13) has 9 to 21 carbon atoms, preferably 9 to 19 carbon atoms, and more preferably 9 to 17 carbon atoms.
The carbon number of R ² in the component (A13) is 1 to 6, preferably 1 to 3, and most preferably 1.
In addition, in component (A13), s is an integer from 3 to 25, preferably from 5 to 18, more preferably from 10 to 18, and particularly preferably from 12 to 18. t is an integer from 0 to 6, and preferably from 0 to 3. u is an integer from 0 to 20, and preferably from 0 to 10. s+u is preferably an integer from 3 to 25, more preferably from 10 to 20, and particularly preferably from 12 to 18.

Among the components (A13), from the viewpoint of improving the detergency and the solubility of the liquid detergent composition, a compound in which R ¹ is an alkyl or alkenyl group having 11 to 17 carbon atoms, R ² is a methyl group, s is 15, and t is 0 (polyoxyethylene fatty acid methyl ester, hereinafter also referred to as "MEE") is particularly preferred. Furthermore, R ¹ in MEE is preferably an alkyl group having 11 carbon atoms and an alkyl group having 13 carbon atoms, or an alkyl group and an alkenyl group having 17 carbon atoms, or an alkyl group and an alkenyl group having 15 or 17 carbon atoms. MEE is less likely to remain on clothing than other nonionic surfactants or anionic surfactants.
An example of a commercially available MEE product is "CEAO-90" manufactured by Lion Corporation.

R ¹ in the component (A14) has 8 to 22 carbon atoms, preferably 10 to 20 carbon atoms, and more preferably 12 to 18 carbon atoms.
In addition, in component (A14), s is 3 to 25, preferably 5 to 20, more preferably 5 to 15, and even more preferably 5 to 10. t is 0 to 6, preferably 0 to 3. u is 0 to 20, preferably 0 to 15, and more preferably 0 to 10. s+u is preferably 3 to 30, more preferably 5 to 25, even more preferably 5 to 20, particularly preferably 5 to 15, very preferably 5 to 10, and most preferably 5 to 8.
Examples of commercially available products in which some or all of the hydrocarbon groups of R ¹ are branched include, for example, DIADOLL (registered trademark) manufactured by Mitsubishi Chemical Corporation (C13, the number after C indicates the carbon number of the alcohol, the same applies below), Neodol (registered trademark) manufactured by Shell (a mixture of C12 and C13), Safol (registered trademark) 23 (a mixture of C12 and C13), and EXXAL (registered trademark) 13 (C13) manufactured by Sasol, in which 3 to 10 moles of ethylene oxide are added to alcohol; and products in which 3, 5, or 7 moles of ethylene oxide are added to a C13 alcohol obtained by subjecting an alkene having a carbon number of 12 obtained by trimerizing butene to the oxo method (Lutensol (registered trademark) TO3, Lutensol TO5, Lutensol TO7, manufactured by BASF); a product in which 12 or 15 moles of ethylene oxide are added to a C13 alcohol obtained by subjecting an alkene having 12 carbon atoms, obtained by trimerizing butene, to the oxo method (Lutensol (registered trademark) TO12, Lutensol TO15, etc., manufactured by BASF); a product in which 9 moles of ethylene oxide are added to a C10 alcohol obtained by subjecting pentanol to the Guerbet reaction (Lutensol XP90, manufactured by BASF); a product in which 7 moles of ethylene oxide are added to a C10 alcohol obtained by subjecting pentanol to the Guerbet reaction (Lutensol XL70, manufactured by BASF); a product in which 6 moles of ethylene oxide are added to a C10 alcohol obtained by subjecting pentanol to the Guerbet reaction (Lutensol XA60, manufactured by BASF).

Among these, there are also cases where the compound is a "mixture" of a compound that is component (A14) and a component (AX), such as Safol 23 (branching ratio: 50 mass%) manufactured by Sasol (an alcohol obtained by subjecting olefins obtained from coal gasification to an oxo process, and then hydrogenating the alcohol) and Neodol 23 (branching ratio: 20 mass%) manufactured by Shell Chemicals (an alcohol produced from n-olefins by a modified oxo process, followed by rectification).
The "branching ratio" refers to the ratio (mass %) of ^R1 having a branched chain to the total ^R1 .

Examples of the component (A1) other than the components (A11), (A12), (A13), and (A14) include polyoxyalkylene-type nonionic surfactants that have conventionally been used in liquid detergents for clothing, etc.
Examples of the component (A) other than the component (A1) include nonionic surfactants that have conventionally been used in liquid detergents for clothing and the like.
Examples of such compounds include polyoxyalkylene alkylamines, alkylphenols, alkylene oxide adducts of higher amines, fatty acid alkanolamines, fatty acid alkanolamides, polyhydric alcohol fatty acid esters or their alkylene oxide adducts, polyhydric alcohol fatty acid ethers, alkyl (or alkenyl) amine oxides, alkylene oxide adducts of hydrogenated castor oil, sugar fatty acid esters, N-alkyl polyhydroxy fatty acid amides, and alkyl glycosides.
These components (A) are readily available on the market, and may be synthesized by a known method.
The component (A) may be used alone or in combination of two or more types.

The total content of component (A) is 35 to 50 mass %, preferably 37 to 48 mass %, and more preferably 40 to 48 mass %, based on the total mass of the liquid detergent composition.
When the total content of the component (A) is 35 mass% or more, the cleaning power against sebum stains is enhanced.
By controlling the total content of the component (A) to 50 mass % or less, the liquid stability of the liquid detergent composition is improved when stored at low temperatures.

The total content of the component (A1) (i.e., the total content of one or more components selected from the group consisting of the components (A11), (A12), (A13), and (A14)) is preferably 35 to 50 mass%, more preferably 37 to 48 mass%, and even more preferably 40 to 48 mass%, relative to the total mass of the liquid detergent composition.
When the total content of the component (A1) is 35 mass% or more, the sebum cleansing power is enhanced.
By controlling the total content of the component (A1) to 50 mass % or less, the liquid stability of the liquid detergent composition during low-temperature storage is improved.

The ratio of the content of the component (A1) to the total content of the component (A) in the liquid detergent composition is preferably 50 to 100 mass%, more preferably 60 to 100 mass%, and even more preferably 70 to 100 mass%.
When the ratio of the content of the component (A1) to the total content of the component (A) is within the above range, the cleaning power against sebum stains is enhanced.

The ratio of the combined content of the components (A11), (A12), (A13) and (A14) to the total content of the component (A1) in the liquid detergent composition is preferably 50 to 100 mass%, more preferably 60 to 100 mass%, and even more preferably 70 to 100 mass%.
When the ratio of the combined content of the components (A11), (A12), (A13), and (A14) to the total content of the component (A1) is within the above range, the cleaning power against sebum stains is enhanced.

When the liquid detergent composition contains the component (A13), the content of the component (A13) relative to the total content of the component (A) in the liquid detergent composition is preferably 50 to 100 mass%, more preferably 60 to 100 mass%, and even more preferably 70 to 100 mass%.
By ensuring that the ratio of the content of the component (A13) relative to the total content of the component (A) is within the above range, the cleaning power against sebum stains is enhanced.

The content of component (A13) is preferably 35 to 50 mass %, more preferably 37 to 48 mass %, and even more preferably 40 to 48 mass %, relative to the total mass of the liquid detergent composition.
When the content of the component (A13) is 35 mass% or more, the sebum cleansing power is enhanced.
By controlling the content of the component (A13) to 50 mass % or less, the liquid stability of the liquid detergent composition during low-temperature storage is improved.

The component (A) preferably consists of one or more selected from the components (A11), (A12), (A13), and (A14).
The component (A) preferably contains the component (A13), and particularly preferably consists solely of the component (A13).
When two or more of them are used in combination, a combination of the components (A13) and (A14) and a combination of the components (A11) and (A12) are preferred.
The component (A14) which is the component (A) may contain the component (AX) mixed therein. In the case where the component (A) and the component (AX) are mixed, the content of the component (AX) is preferably 42 mass % or less, more preferably 35 mass % or less, based on the total mass of the liquid detergent composition.

<Component (B)>
Component (B) is a non-soap anionic surfactant. The term "non-soap anionic surfactant" refers to an anionic surfactant other than higher fatty acids or salts thereof (so-called soaps).
The component (B) preferably contains one or more components selected from the group consisting of the following components (B1), (B2), (B3), and (B4).

Component (B1): Linear alkylbenzene sulfonic acid or a salt thereof.
Component (B2): polyoxyalkylene alkyl(alkenyl) ether sulfate or a salt thereof.
Component (B3): α-olefin sulfonic acid or a salt thereof.
Component (B4): internal olefin sulfonic acid or its salt.

The alkyl group in the component (B1) preferably has 8 to 18 carbon atoms, more preferably 8 to 16 carbon atoms, and even more preferably 10 to 16 carbon atoms.
Examples of salts of linear alkylbenzenesulfonic acid include alkali metal salts with sodium, potassium, etc., alkaline earth metal salts with magnesium, etc., and alkanolamine salts with monoethanolamine, diethanolamine, etc.

Examples of the component (B2) include a compound represented by the following general formula (b-1) (hereinafter referred to as "compound (b-1)").
R ³ -O-[(EO) _k /(PO) _n ]-SO ₃ ^- M ⁺ ... (b-1)
In formula (b-1), ^R3 is a linear or branched alkyl group having 8 to 20 carbon atoms or a linear or branched alkenyl group having 8 to 20 carbon atoms, EO is an oxyethylene group, PO is an oxypropylene group, k is a number of 0.1 or more indicating the average number of repetitions of EO, n is a number of 0 to 6 indicating the average number of repetitions of PO, [(EO) _k /(PO) _n ] indicates that there is no limitation on the order of arrangement of EO and PO, and M ⁺ is a counter cation.
The content of the component (b-0) in formula (b-1) where k=0 and n=0 is preferably 35 to 55 mass % relative to the total mass of the component (B2).

^R3 is preferably a linear or branched alkyl or alkenyl group having 10 to 20 carbon atoms, and more preferably a linear or branched alkyl or alkenyl group having 12 to 14 carbon atoms.
In particular, a straight-chain alkyl group having 10 to 20 carbon atoms is preferred, and a straight-chain alkyl group having 12 to 14 carbon atoms is more preferred.
k is preferably from 0.1 to 5, more preferably from 0.1 to 3, further preferably from 0.5 to 2, and particularly preferably from 0.5 to 1.5.
n is preferably 0 to 3, and more preferably 0.
k+n is preferably 0.1 or more, and more preferably 1 to 5.

From the viewpoint of sebum cleansing power, the compound (b-1) is preferably a polyoxyethylene alkyl ether sulfate in which k is 0.5 or more and n is 0, or a salt thereof.
The k of the polyoxyethylene alkyl(alkenyl) ether sulfate or a salt thereof is preferably from 0.1 to 5, more preferably from 0.1 to 3, further preferably from 0.5 to 2, and particularly preferably from 0.5 to 1.5.

When neither k nor n is 0, that is, when compound (b-1) has both EO and PO, the distribution (arrangement order) of EO and PO is not particularly limited, and they may be arranged in a block form or randomly.
Examples of the method for arranging EO and PO in a block form include a method of introducing ethylene oxide and then propylene oxide, a method of introducing propylene oxide and then ethylene oxide, and a method of introducing ethylene oxide, then propylene oxide, and further introducing ethylene oxide.
Examples of the salts of polyoxyalkylene alkyl ether sulfates include alkali metal salts with sodium, potassium, etc., alkaline earth metal salts with magnesium, etc., and alkanolamine salts with monoethanolamine, diethanolamine, etc.

The component (B3) preferably has 8 to 24 carbon atoms, and more preferably 10 to 20 carbon atoms.
Examples of the salts of α-olefinsulfonic acid include alkali metal salts with sodium, potassium, etc., alkaline earth metal salts with magnesium, etc., and alkanolamine salts with monoethanolamine, diethanolamine, etc.

The component (B4) preferably has 8 to 24 carbon atoms, and more preferably 10 to 20 carbon atoms.
Examples of the salts of internal olefin sulfonic acid include alkali metal salts with sodium, potassium, etc., alkaline earth metal salts with magnesium, etc., and alkanolamine salts with monoethanolamine, diethanolamine, etc.

Examples of the (B) component other than the (B1), (B2), (B3), and (B4) components include anionic surfactants that have conventionally been used in liquid detergents for clothing and the like.
For example, linear or branched alkyl sulfate esters or salts thereof; alkanesulfonic acids or salts thereof having an alkyl group; α-sulfofatty acid esters or salts thereof (MES); carboxylic acid type anionic surfactants such as alkyl ether carboxylic acids or salts thereof, polyoxyalkylene ether carboxylic acids or salts thereof, alkylamide ether carboxylic acids or salts thereof, alkenylamide ether carboxylic acids or salts thereof, and acylamino carboxylic acids or salts thereof; phosphate ester type anionic surfactants such as alkyl phosphate esters or salts thereof, polyoxyalkylene alkyl phosphate esters or salts thereof, polyoxyalkylene alkylphenyl phosphate esters or salts thereof, and glycerin fatty acid ester monophosphate esters or salts thereof.
Examples of the salt form of these anionic surfactants include alkali metal salts such as sodium and potassium; alkaline earth metal salts such as magnesium; and alkanolamine salts such as monoethanolammonium and diethanolammonium.

These components (B) are readily available on the market, and may be synthesized by a known method.
The component (B) may be used alone or in combination of two or more types.

The total content of component (B) is 15 to 30 mass %, preferably 17 to 27 mass %, and more preferably 20 to 25 mass %, based on the total mass of the liquid detergent composition.
When the total content of the component (B) is 15 mass% or more, the cleaning power against protein stains is enhanced.
By controlling the total content of the (B) component to 30 mass % or less, the liquid stability of the liquid detergent composition is improved when stored at low temperatures.

The (B) component includes one or more components selected from the group consisting of the (B1) component, the (B2) component, the (B3) component, and the (B4) component. The total content of the (B) component is preferably 15 to 30 mass %, more preferably 17 to 27 mass %, and even more preferably 20 to 25 mass %, relative to the total mass of the liquid detergent composition.
When the total content of the components (B1), (B2), (B3) and (B4) is 15 mass% or more, the cleaning power against proteinaceous stains is enhanced.
By controlling the total content of the components (B1), (B2), (B3) and (B4) to 30 mass % or less, the low temperature stability of the liquid detergent composition becomes good.

The ratio of the combined content of the (B1), (B2), (B3) and (B4) components to the total content of the (B) component in the liquid detergent composition is preferably 60 to 100 mass%, more preferably 65 to 100 mass%, and even more preferably 70 to 100 mass%.
When the ratio of the combined content of the components (B1), (B2), (B3), and (B4) to the total content of the component (B) is 60 mass% or more, the cleaning power against proteinaceous stains is enhanced.

The component (B) preferably contains a component (B1).
The ratio of the content of the component (B1) to the total content of the component (B) in the liquid detergent composition is preferably 60 to 100 mass%, more preferably 65 to 100 mass%, and even more preferably 70 to 100 mass%.
When the proportion of the component (B1) relative to the total content of the component (B) is 60 mass % or more, the cleaning power against proteinaceous stains is enhanced.

The content of component (B1) is preferably 15 to 30 mass %, more preferably 17 to 27 mass %, and even more preferably 20 to 25 mass %, relative to the total mass of the liquid detergent composition.
By ensuring that the content of the component (B1) is 15 mass% or more, the cleaning power against protein stains is enhanced.
By controlling the content of the component (B1) to 30 mass % or less, the low temperature stability of the liquid detergent composition is improved.

The combined content of components (A) and (B) is 50 to 70 mass %, preferably 53 to 68 mass %, and more preferably 57 to 65 mass %, based on the total mass of the liquid detergent composition.
When the total content of the components (A) and (B) is 50% by mass or more, sufficient cleaning power can be exhibited even with a small amount used.
By ensuring that the total content of components (A) and (B) is 70 mass% or less, the liquid stability during low-temperature storage is improved.

The ratio of the mass of the component (A) to the mass of the component (B) [(A)/(B)] is preferably from 1.5 to 2.5, more preferably from 1.7 to 2.3, and particularly preferably from 1.7 to 2.0.
When [(A)/(B)] is within the above range, the liquid stability during low-temperature storage is improved.
The ratio of the mass of the component (A13) to the mass of the component (B1) [(A13)/(B1)] is preferably from 1.5 to 2.5, more preferably from 1.7 to 2.3, and particularly preferably from 1.7 to 2.0.

<Component (C)>
The component (C) is an organic solvent having a hydroxyl group. The component (C) preferably contains a glycol ether having both a hydroxyl group and an etheric oxygen, and more preferably contains an aromatic glycol ether having a hydroxyl group.
The component (C) may be used alone or in combination of two or more types.
Specific examples of the component (C) include phenoxyethanol, ethanol, propylene glycol, butyl carbitol, and glycerin. Among these, phenoxyethanol is preferred, and it is particularly preferred to use only phenoxyethanol as the component (C).

The content of component (C) is 3% by mass or less based on the total mass of the liquid detergent composition. That is, the liquid detergent composition does not need to contain component (C), but it is preferable that the content of component (C) is more than 0% by mass.
When component (C) is contained, the total content thereof is preferably more than 0 mass% and not more than 3 mass%, more preferably 0.5 to 2.5 mass%, and even more preferably 1 to 2 mass%, relative to the total mass of the liquid detergent composition.
When the content of component (C) exceeds 0 mass %, the viscosity of the liquid detergent composition is reduced, improving ease of use and solubility in cold water.
By ensuring that the content of component (C) is 3 mass% or less, the liquid stability during low-temperature storage is improved, and the improved enzyme stability makes it easier to prevent a decrease in the detergency of the liquid detergent composition after storage.
On the other hand, when the (C) component is not contained (when the component is 0 mass %), the liquid stability during low-temperature storage can be increased, but the solubility in cold water and the effect of reducing the viscosity of the liquid detergent composition are inferior to when the (C) component is contained.

The liquid detergent composition may contain an organic solvent other than the component (C) as long as the effects of the present invention are not impaired, but it is preferable that the liquid detergent composition does not contain such an organic solvent.
Examples of organic solvents other than component (C) include organic solvents that have conventionally been used in liquid detergents for clothing and the like.

The ratio of the mass of the component (C) to the total mass of the components (A) and (B), [(C)/{(A)+(B)}], is preferably 0 to 0.07, more preferably 0 to 0.06, and even more preferably 0 to 0.05.
When the component (C) is contained, [(C)/{(A)+(B)}] is preferably 0.001 to 0.07, more preferably 0.01 to 0.06, and even more preferably 0.01 to 0.05. When the component (C) is not contained, [(C)/{(A)+(B)}] is 0.
When [(C)/{(A)+(B)}] is within the above range, the liquid stability during low-temperature storage is improved.
When the component (C) is phenoxyethanol, the component (A) is (A13), and the component (B) is (B1), the ratio of the mass of phenoxyethanol to the total mass of the components (A13) and (B1) [(phenoxyethanol)/{(A13)+(B1)}] is preferably 0.01 to 0.07, more preferably 0.01 to 0.06, and even more preferably 0.01 to 0.05.

<Component (D)>
Component (D) is a protease. The protease is preferably a protease having serine, histidine, and aspartic acid in the molecule, such as a serine protease.
Enzyme preparations containing proteases (protease preparations) are commercially available. When preparing liquid detergents, proteases are usually formulated using these 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, 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, Coronase 48L Progress Uno 100L; examples of the product available from Genencor include Purafect L, Purafect OX, and Properase L.
Among these, Everlase 16L, Alcalase 2.5L, Coronase 48L, and Progress Uno 100L are preferred, with Progress Uno 100L being more preferred.

The content of component (D) as an enzyme preparation is 2 to 5 mass %, preferably 2 to 4 mass %, more preferably 2.5 to 4 mass %, and even more preferably 2.5 to 3.5 mass %, relative to the total mass of the liquid detergent composition.
By ensuring that the content of component (D) is 2 mass% or more, the cleaning power against protein stains is enhanced.
By controlling the content of component (D) to 5 mass % or less, precipitation of the enzyme during low-temperature storage can be suppressed, and the liquid stability of the liquid detergent composition can be improved.

When the component (C) is contained, the ratio of the mass of the component (C) to the mass of the component (D) [(C)/(D)] is preferably from 0.1 to 1.6, more preferably from 0.1 to 1.3, and even more preferably from 0.1 to 1.1.
The ratio of the mass of the component (A) to the mass of the component (D) [(A)/(D)] is preferably 7-25, more preferably 10-20, and even more preferably 10-15.
The ratio of the mass of the component (B) to the mass of the component (D) [(B)/(D)] is preferably 3-15, more preferably 5-12, and even more preferably 5-10.
The ratio of the total mass of the components (A) and (B) to the mass of the component (D), [{(A)+(B)}/(D)], is preferably from 10 to 35, more preferably from 15 to 30, and even more preferably from 15 to 25.

<Water>
The water is not particularly limited, and examples thereof include purified water, distilled water, ion-exchanged water, tap water, etc. As the water, one of these may be used alone, or two or more of them may be used in combination.
The water content is preferably 10 to 30 mass %, more preferably 15 to 28 mass %, and even more preferably 20 to 28 mass %, based on the total mass of the liquid detergent composition.
If the water content is 10% by mass or more, the stability of the protease is easily obtained.
If the water content is 30 mass % or less, it is easy to obtain a highly concentrated liquid detergent composition.

<Higher fatty acid or its salt>
The liquid detergent composition of the present invention may further contain a higher fatty acid or a salt thereof.
By "higher fatty acid" is meant a fatty acid having 8 to 22 carbon atoms.
Although higher fatty acids or their salts are classified as anionic surfactants, their action differs from that of the non-soap anionic surfactant (B) in that they function as foam inhibitors and contribute to improved rinsing performance, which can reduce the number of rinsing steps required after cleaning.

As the higher fatty acid, any higher fatty acid used in general liquid detergents can be used, and among them, fatty acids having 8 to 22 carbon atoms are preferable. The number of carbon atoms of the fatty acid is preferably 10 to 20, and more preferably 12 to 18.
The higher fatty acid may be a saturated fatty acid, an unsaturated fatty acid, or a mixture of a saturated fatty acid and an unsaturated fatty acid. Examples of the fatty acid include stearic acid, linoleic acid, oleic acid, and coconut fatty acid.

Examples of salt forms of higher fatty acids 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, etc.).

The higher fatty acid or its salt may be used alone or in combination of two or more kinds.
The content of the higher fatty acid or its salt is preferably 2% by mass or more, more preferably 2.5% by mass or more, based on the total mass of the liquid detergent composition. Also, the content is preferably 10% by mass or less, more preferably 7% by mass or less, based on the total mass of the liquid detergent composition. That is, the content is preferably 2 to 10% by mass, more preferably 2.5 to 7% by mass, based on the total mass of the liquid detergent composition.
When the content of the higher fatty acid or a salt thereof is within the above range, the antifoaming property is enhanced and the enzyme stability after high-temperature storage is easily obtained.

The total content of the higher fatty acid and component (B) (non-soap anionic surfactant) is preferably from 17 to 40% by mass, more preferably from 19 to 37% by mass, and even more preferably from 22 to 35% by mass.
The ratio of the mass of the higher fatty acid or a salt thereof to the mass of the component (D) [(higher fatty acid or a salt thereof)/(D)] is preferably from 0.4 to 5, more preferably from 0.4 to 3, and even more preferably from 0.4 to 1.5.

<Other enzymes>
The liquid detergent composition of the present invention may contain an enzyme other than a protease.
Examples of enzymes other than proteases include amylase, lipase, cellulase, and mannanase.

Preferred amylases include α-amylase, β-amylase, α-glucosidase, glucoamylase; glucoamylase which hydrolyzes α-1,6 bonds in starch, glycogen, etc., pullulanase, isoamylase, amylo-1,6 glucosidase/4-α glucanotransferase, oligo-1,6-glucosidase, etc.
Enzyme preparations containing amylase (amylase preparations) are commercially available. When preparing liquid detergents, amylase is usually formulated using these amylase preparations.
Examples of amylase preparations include Termamyl Ultra 300L, Duramyl 16L, Stainzyme 12L, Promozyme 200L, Amplify Prime 100L, Medley (registered trademark) Core 210L (mixture of protease and amylase, all trade names; manufactured by Novozymes); Maxamyl (trade name; manufactured by Genencor), Pullulanase Amano (trade name; manufactured by Amano Pharmaceutical Co., Ltd.), DB-250 (trade name; pullulanase derived from Aerobacter aerogenes ATCC9621, crude or crystallized product; manufactured by Seikagaku Corporation), and the like. Among these, Duramyl 16L, Stainzyme 12L, Termamyl Ultra 300L, and Amplify Prime 100L (all trade names; manufactured by Novozymes) are preferred, with Amplify Prime 100L being more preferred.

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).
Examples of mannanase preparations include those available from Novozymes under the trade names Mannaway 4L and Mannaway 200L.

The total content of enzymes other than proteases as an enzyme preparation is preferably 0.1 to 10% by mass, more preferably 0.2 to 5% by mass, based on the total mass of the liquid detergent composition.

<Single-chain alkylbenzene sulfonic acid>
The liquid detergent composition of the present invention may further contain a short-chain alkylbenzene sulfonic acid. The short-chain alkylbenzene sulfonic acid means an alkylbenzene sulfonic acid having a straight or branched chain and a carbon number of 1 to 5. Examples of the short-chain alkylbenzene sulfonic acid include meta-xylene sulfonic acid, cumene sulfonic acid, para-toluene sulfonic acid (pTS), and ethylbenzene sulfonic acid. Among the short-chain alkylbenzene sulfonic acids, para-toluene sulfonic acid is preferred from the viewpoint of odor suppression of the liquid detergent composition.
The content of the short-chain alkylbenzene sulfonic acid is preferably 0.1 to 10 mass %, more preferably 0.5 to 5 mass %, based on the total mass of the liquid detergent composition.
By setting the content of the short-chain alkylbenzene sulfonic acid within the above range, the viscosity of the liquid detergent composition is reduced, improving usability, and gelling or solidification of the liquid detergent composition during low-temperature storage can be suppressed, and precipitation of the enzyme during high-temperature storage can be suppressed.

<Other optional ingredients>
The liquid detergent composition may contain components known in the field of liquid detergents, provided that the effects of the present invention are not impaired.
Examples of optional components include surfactants other than component (A) and component (B), bleaching agents, fluorescent brightening agents, soil release agents, polymers such as alkylene oxide adducts of polyalkyleneamines, dispersants, defoamers (excluding component (A) and higher fatty acids or salts thereof), pH adjusters, chelating agents, alkali agents, texture improvers, antibacterial agents, preservatives, antioxidants, fragrances, colorants, and the like.

Surfactants other than components (A) and (B) include cationic surfactants, semi-polar surfactants, amphoteric surfactants, etc. Specific examples are given below.

(Cationic Surfactant)
The cationic surfactant may be, for example, an alkylamidoamine, and is preferably contained in an amount of 0.1 to 20% by mass, more preferably 1 to 10% by mass, based on the total mass of the liquid detergent composition.

(Amphoteric surfactant)
Examples of amphoteric surfactants include alkyl betaine type, alkyl amide betaine type, imidazoline type, alkyl amino sulfone type, alkyl amino carboxylic acid type, alkyl amide carboxylic acid type, amide amino acid type, phosphoric acid type, etc. The content of the amphoteric surfactant is preferably 0.1 to 20 mass %, more preferably 1 to 10 mass %, based on the total mass of the liquid detergent composition.

(Semi-polar surfactants)
Examples of semi-polar surfactants include lauryl dimethylamine oxide, lauric acid amide propyl dimethylamine oxide, etc. The content of the semi-polar surfactant is preferably 0.1 to 20 mass %, more preferably 1 to 10 mass %, based on the total mass of the liquid detergent composition.
The content of the total surfactants including the component (A), the component (B), the higher fatty acid or a salt thereof, the cationic surfactant, the semi-polar surfactant, and the amphoteric surfactant is preferably 52 to 80%, and more preferably 52 to 70%.

Examples of bleaching agents include hydrogen peroxide. The bleaching agent is preferably present in an amount of 0.01 to 10% by mass based on the total mass of the liquid detergent composition.

Fluorescent brightening agents include biphenyl-type fluorescent brightening agents such as 4,4'-bis(2-sulfostyryl)biphenyl disodium salt, and stilbene-type fluorescent brightening agents such as 4,4'-bis((4-amino-6-morpholino-1,3,5-triazinyl-2)amino)stilbene-2,2'-disulfonate. These fluorescent brightening agents may be used alone or in combination of two or more. The amount of these fluorescent brightening agents is preferably 0.01 to 10% by mass based on the total mass of the liquid detergent composition.

Examples of soil release agents include polymers having at least one repeating unit selected from the group consisting of alkylene terephthalate units and alkylene isophthalate units, and oxyalkylene units. Examples of such polymers include those described in International Publication No. 2017/142012. Examples of commercially available SR agents include "TexCare SRN-170" manufactured by Clariant.

Further, polymers such as alkylene oxide adducts of polyalkyleneamines can be mentioned. Examples of alkylene oxide adducts of polyalkyleneamines include those described in International Publication No. 2017/142012 and JP-A-2017-514967. Examples of commercially available products include the product name "Sokalan HP20" manufactured by BASF.
Further, the cationic cellulose described in JP-A-2019-90057 can be used.
The amount of these soil release agents is preferably 0.1 to 20% by mass based on the total mass of the liquid detergent composition.

Examples of dispersants include polyacrylic acid and its salts, polymethacrylic acid and its salts, and polymeric polycarboxylic acids or their salts. The amount of these dispersants is preferably 0.01 to 5% by mass based on the total mass of the liquid detergent composition.

Examples of the defoaming agent (excluding component (A) and higher fatty acids or salts thereof) include propylene oxide adducts of alcohols (excluding component (A)), fatty acid esters, etc. Examples of the propylene oxide adducts of alcohols (excluding component (A)) include those in which propylene oxide is added to monoalcohols such as methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, etc.; those in which propylene oxide is added to diols such as ethanediol, triols such as glycerin, tetraols such as erythritol, hexaols such as sorbitol, and other polyhydric alcohols. The defoaming agent is preferably present in an amount of 0.1 to 10% by mass based on the total mass of the liquid detergent composition.

Examples of fatty acid esters include 2-ethylhexyl 2-ethylhexanoate (also known as 2-ethylhexyl isooctanoate, 2H08). These defoamers are preferably present in an amount of 0.01 to 5% by mass relative to the total mass of the liquid detergent composition.

Examples of pH adjusters include inorganic acids such as hydrochloric acid, sulfuric acid, and phosphoric acid, sodium hydroxide, potassium hydroxide, alkanolamines, and ammonia. These pH adjusters may be used alone or in combination of two or more.

Examples of chelating agents include organic phosphonic acids such as lactic acid, ethylenediaminetetraacetic acid (EDTA), triethylenetetraacetic acid (TTHA), methylglycine diacetic acid (MGDA), hydroxyiminodisuccinic acid (HIDS), diethylenetriaminepentaacetic acid (DTPA), and 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP) or their salts. Examples of salt forms of chelating agents include sodium, potassium, calcium, and magnesium. These chelating agents may be used alone or in combination of two or more. The amount of these chelating agents is preferably 0.001 to 10% by mass based on the total mass of the liquid detergent composition.

Examples of alkaline agents include alkanolamines (monoethanolamine, diethanolamine, triethanolamine, etc.). These alkaline agents may be used alone or in combination of two or more. The amount of these alkaline agents is preferably 0.1 to 5% by mass based on the total mass of the liquid detergent composition.

Examples of texture improvers include silicones such as dimethyl silicone, polyether-modified silicone, and amino-modified silicone. Examples of these silicones include oil type, oil compound type, solution type, emulsion type, and self-emulsifying type. These texture improvers may be used alone or in combination of two or more types. The amount of these texture improvers is preferably 0.1 to 20% by mass based on the total mass of the liquid detergent composition.

Examples of antibacterial agents (excluding the cationic surfactants mentioned above) include cationic disinfectants such as diclosan, triclosan, and quaternary ammonium salts (benzalkonium chloride, etc.). These antibacterial agents may be used alone or in combination of two or more. The amount of these antibacterial agents is preferably 0.001 to 10% by mass, more preferably 0.01 to 5% by mass, and even more preferably 0.1 to 3% by mass, based on the total mass of the liquid detergent composition.

Examples of preservatives include "Casson CG" (trade name) manufactured by Dow Chemical Company, "Acticide MBS" (trade name) manufactured by Thor Japan, and "NIPACIDE BIT 20" (trade name) manufactured by Clariant. These preservatives may be used alone or in combination of two or more kinds. The amount of these preservatives is preferably 0.001 to 1% by mass based on the total mass of the liquid detergent composition.

Examples of antioxidants include BHT (dibutylhydroxytoluene) and BHA (butylhydroxyanisole). These antioxidants may be used alone or in combination of two or more. The amount of these antioxidants is preferably 0.01 to 3% by mass based on the total mass of the liquid detergent composition.

The fragrance may be a fragrance raw material alone or a fragrance composition consisting of a fragrance raw material, a fragrance solvent, a fragrance stabilizer, etc., and fragrances that are normally used in liquid detergent compositions may be blended. Capsule fragrances may also be blended. The amount is preferably 0.01 to 5% by mass based on the total mass of the liquid detergent composition.

Examples of dyes include quinone dyes, triphenylmethane dyes, xanthene dyes, quinoline dyes, and pyrene dyes. In this specification, the "C.I." below is an abbreviation for color index. The structure of each dye is described in the "Legal Dyes Handbook" (edited by the Japan Cosmetic Industry Council) and the Dyes Handbook (edited by the Society of Organic Synthesis Chemistry).

Examples of quinone dyes include C.I. Solvent Blue 63 (C.I. Solvent Blue 63, Blue No. 403), and products under the trade names of Liquitint Blue HP and Liquitint Blue BL manufactured by Milliken Corporation.
An example of the triphenylmethane dye is Green No. 3 (C.I. 42053).
An example of the quinoline dye is C.I. Acid Yellow 3. The dye is preferably present in an amount of 0.1 to 100 ppm by mass based on the total mass of the liquid detergent composition.

<Physical Properties>
The pH of the liquid detergent composition at 25° C. is preferably from 6 to 8, more preferably from 6.5 to 7.5.
The pH of the liquid detergent composition can be adjusted, if necessary, by adding a pH adjuster.
The pH is a value measured at 25° C. using a pH meter (product name: HM-30G, manufactured by DKK-TOA Corporation).

<Production Method>
The liquid detergent composition of the present invention can be produced according to a method for producing a liquid detergent composition known in the art. For example, the liquid detergent composition can be produced by adding each component except the pH adjuster to a part of water and mixing them, then adding the pH adjuster as necessary to adjust the pH, and then adding the rest of the water to make the total amount 100 mass%. The obtained liquid detergent composition is preferably placed in a container such as a squeeze container to make a container-packed liquid detergent product.

<How to use>
Methods for using the liquid detergent composition include, for example, a method in which the liquid detergent composition is placed in a liquid detergent composition inlet of a washing machine and then the washing machine is operated, a method in which the liquid detergent composition is placed in water together with the article to be washed when washing, a method in which the article to be washed is immersed in a cleaning liquid prepared in advance by dissolving the liquid detergent composition in water, a method in which the liquid detergent composition is directly applied to the article to be washed and left for, for example, 3 minutes to 24 hours, and then a normal washing is performed, and the like.

It is also preferable to use a washing machine equipped with an automatic detergent dispensing function, which has been put into practical use in recent years. The automatic detergent dispensing function automatically dispenses detergent from a tank containing the detergent into the washing tub via a dispensing pipe. A measuring device such as a syringe pump is provided in the dispensing pipe, and a fixed amount of detergent, set according to the amount of laundry, can be transferred from the tank to the washing tub.

Using the automatic detergent dispensing function not only saves the trouble of measuring the amount of detergent, but also prevents the liquid detergent composition from sticking to your hands when measuring the amount, or from spilling and soiling the washing machine or surrounding area.
In addition, since the liquid detergent composition of the present invention is a concentrated type, the amount used per wash may be very small, about 10 mL. Such a small amount of liquid detergent composition is difficult to measure accurately using a cap or the like, and the amount of liquid is likely to be insufficient or excessive. By using the detergent automatic injection function, even a small amount of liquid detergent composition can be accurately measured, making it easier to demonstrate sufficient cleaning power and avoiding waste due to overuse, which is preferable.

It is also preferable to use an automatic dispenser capable of automatically discharging a predetermined amount of liquid. When an automatic dispenser is used, even a small amount of the liquid detergent composition can be accurately measured, so that sufficient cleaning power can be easily exhibited and waste due to overuse can be avoided, which is preferable.
Some automatic dispensers are commercially available that use an infrared sensor or the like to automatically dispense the liquid detergent composition without touching a switch, etc. By using such an automatic dispenser, the liquid detergent composition can be measured out simply by holding the container in one hand, which significantly reduces the burden on the user.

In addition, when an automatic dispenser is used, it is also preferable to receive the liquid detergent composition discharged into a soft container and then directly put the soft container into the washing machine, so that the entire amount of the discharged liquid detergent composition can be reliably dissolved in the cleaning liquid.
Examples of materials for the soft container that can be directly put into the washing machine include silicone resin, polyvinyl chloride, elastomer, soft polyester, soft polypropylene, polyurethane, and the like.

Examples of items to be washed include textile products such as clothing, dishcloths, towels, sheets, curtains, 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.
When the liquid detergent composition is used by dissolving it in water, it is preferably diluted, for example, 5 to 5,000 times (by volume).
The liquor ratio, which is the amount of water per amount of clothes (mass of washing liquid during washing/mass of clothes), is preferably 5 or more for a drum type washing machine and 10 or more for a vertical washing machine.
The amount of the liquid detergent composition used in the cleaning treatment is preferably 10 to 500, more preferably 10 to 300, and even more preferably 10 to 100, in terms of the ratio of the total mass of the items to be washed (mass of fabric) to the total mass of the liquid detergent composition.
The liquid detergent composition is suitable as a detergent for textile products.

<Action and effect>
Although the liquid detergent composition of the present invention has a high surfactant concentration and is highly concentrated, the protease is unlikely to precipitate even when stored at low temperatures, and the decrease in protease activity after storage at high temperatures can be suppressed.
Since the liquid detergent composition of the present invention is highly concentrated, the amount used per wash is small. In addition, the container for storing the liquid detergent composition can be made smaller, which contributes to reducing energy consumption and waste during distribution.

The liquid detergent composition of the present invention is also less likely to produce precipitates even when stored at low temperatures. This prevents the injection pipes and syringe pumps of washing machines equipped with an automatic detergent injection function from being clogged with precipitates. In addition, when an automatic dispenser is used, the nozzle and discharge mechanism can be prevented from being clogged with precipitates. Therefore, it is possible to install and use a washing machine or automatic dispenser in a place where the temperature fluctuates greatly, such as a balcony.

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 raw materials used in this example are as shown in <Raw Materials Used> below.

<Ingredients used>
[Component (A)]

(A11) Component EO20PO2: A compound in which an average of 20 moles of EO and an average of 2 moles of PO are randomly added to 1 mole of natural alcohol (mass ratio of C12 alcohol/C14 alcohol = 7/3). In the formula (a-1), R ¹ is a linear alkyl group having 12 carbon atoms (C12) and a linear alkyl group having 14 carbon atoms (C14) (mass ratio of C12:C14 = 70:30), R ² is a hydrogen atom, -X- is -O-, the carbon atom of R ¹ to which X is bonded is a primary carbon atom, s is 20, t is 2, and u is 0.

(A12) Component Softanol (5EO): A compound in which 5 moles of ethylene oxide are added to 1 mole of secondary alcohol (mass ratio of alcohol having 12 carbon atoms to alcohol having 14 carbon atoms = 7/3). In the formula (a-1), R ¹ is a linear alkyl group having 12 carbon atoms (C12) and a linear alkyl group having 14 carbon atoms (C14) (mass ratio of C12:C14 = 70:30), R ² is a hydrogen atom, -X- is -O-, the carbon atom of R ¹ to which X is bonded is a secondary carbon atom, s is 5, t is 0, and u is 0.

Softanol (12EO): A compound in which 12 moles of ethylene oxide are added to 1 mole of secondary alcohol (mass ratio of alcohol having 12 carbon atoms/alcohol having 14 carbon atoms=7/3). In the formula (a-1), R ¹ is a linear alkyl group having 12 carbon atoms (C12) and a linear alkyl group having 14 carbon atoms (C14) (mass ratio of C12:C14=70:30), R ² is a hydrogen atom, -X- is -O-, the carbon atom of R ¹ to which X is bonded is a secondary carbon atom, s is 12, t is 0, and u is 0.

Component (A13) MEE: Polyoxyethylene fatty acid methyl ester (coconut fatty acid methyl ester (mixture of methyl laurate/methyl myristate = 8/2 by mass).
In the formula (a-1), a compound in which R ¹ is an alkyl group having 11 to 13 carbon atoms, R ² is a methyl group, -X- is -COO-, the carbon atom of R ¹ to which X is bonded is a secondary carbon atom, s is 15, t is 0, and u is 0. Product name "CEAO-90", manufactured by Lion Corporation.

Component (A14) TAG: polyoxyethylene alkyl ether (a compound in which 7 moles of ethylene oxide are added to an alcohol having 13 carbon atoms. In the general formula (a-1), R ¹ is a branched alkyl group having 13 carbon atoms, the carbon atom of R ¹ bonded to the oxygen atom is a primary carbon atom, R ² is a hydrogen atom, s is 7, t is 0, and u is 0. This compound was synthesized according to Preparation Example 1 below.).

[Preparation Example 1: Synthesis of TAG]
400 g of EXXAL (registered trademark) 13 manufactured by Sasol and 3.33 g of 30% by mass NaOH aqueous solution were charged into a pressure-resistant reactor, and the inside of the reactor was replaced with nitrogen. Next, the temperature was 100°C and the pressure was 2.0 kPa or less for 30 minutes to dehydrate, and then the temperature was raised to 160°C. Next, while stirring the reaction solution, 1145 g of ethylene oxide (gaseous) was gradually added to the reaction solution. 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, the temperature was cooled to 100° C. or less, and the reaction product was neutralized by adding 70% by mass p-toluenesulfonic acid so that the pH of a 1% by mass aqueous solution of the reaction product became about 7, thereby obtaining TAG.

(AX) component AE(5EO): 5 moles of ethylene oxide are added to 1 mole of natural alcohol (mass ratio of C12 alcohol/C14 alcohol=7/3). In formula (a-1), R ¹ is an alkyl group having 12 carbon atoms (C12) and an alkyl group having 14 carbon atoms (C14) (mass ratio of C12:C14=70:30), R ² is a hydrogen atom, -X- is -O-, the carbon atom of R ¹ to which X is bonded is a primary carbon atom, s is 5, t is 0, and u is 0.

AE(15EO): A compound in which 15 moles of ethylene oxide are added to 1 mole of natural alcohol (mass ratio of alcohol having 12 carbon atoms to alcohol having 14 carbon atoms = 7/3). In the formula (a-1), R ¹ is a linear alkyl group having 12 carbon atoms (C12) and a linear alkyl group having 14 carbon atoms (C14) (mass ratio of C12:C14 = 70:30), R ² is a hydrogen atom, -X- is -O-, the carbon atom of R ¹ to which X is bonded is a primary carbon atom, s is 15, t is 0, and u is 0.

AE(25EO): A compound in which 25 moles of ethylene oxide are added to 1 mole of natural alcohol (mass ratio of alcohol having 12 carbon atoms to alcohol having 14 carbon atoms = 7/3). In the formula (a-1), R ¹ is a linear alkyl group having 12 carbon atoms (C12) and a linear alkyl group having 14 carbon atoms (C14) (mass ratio of C12:C14 = 70:30), R ² is a hydrogen atom, -X- is -O-, the carbon atom of R ¹ to which X is bonded is a primary carbon atom, s is 25, t is 0, and u is 0.

[Component (B)]
Component (B1) LAS: linear alkylbenzene sulfonic acid having an alkyl group having 10 to 14 carbon atoms, manufactured by Lion Specialty Chemicals, trade name "Lipon (registered trademark) LH-200".

Component (B2) AES: polyoxyalkylene alkyl ether sulfate (average number of moles of EO added: 1). In formula (b-1), ^R3 is a linear alkyl group having 12 and 14 carbon atoms, k is 1, n is 0, M is sodium, and the proportion of the compound in which k is 0 and n is 0 (component (b-0)) relative to the total amount of AES is 43 mass%. Synthesized by the method of Preparation Example 2 below.

[Preparation Example 2: Synthesis of AES]
Into a 4 L autoclave, 400 g of Procter &Gamble's trade name CO1270 alcohol (a mixture of an alcohol having 12 carbon atoms and an alcohol having 14 carbon atoms in a mass ratio of 75/25) was charged as a raw material alcohol, and 0.8 g of potassium hydroxide catalyst was charged as a reaction catalyst. The atmosphere inside the autoclave was replaced with nitrogen, and the temperature was raised with stirring.
Subsequently, 91 g of ethylene oxide was introduced while maintaining the temperature at 180° C. and the pressure at 0.3 MPa or less, and reacted to obtain an alcohol ethoxylate.
Analysis using a gas chromatograph: GC-5890 manufactured by Hewlett-Packard, a detector: a flame ionization detector (FID), and a column: Ultra-1 (manufactured by HP, L25m×φ0.2mm×T0.11μm) showed that the average number of moles of ethylene oxide added in the obtained alcohol ethoxylate was 1.0. In addition, the amount of compounds to which ethylene oxide was not added (those that ultimately became component (b-0)) was 43% by mass based on the total amount of the obtained alcohol ethoxylate.
Next, 237 g of the alcohol ethoxylate obtained above was placed in a 500 mL flask equipped with a stirrer, and after replacing with nitrogen, 96 g of liquid sulfuric anhydride (sulfane) was slowly added dropwise while maintaining the reaction temperature at 40° C. After the dropwise addition was completed, stirring was continued for 1 hour (sulfation reaction) to obtain polyoxyethylene alkyl ether sulfate. This was then neutralized with an aqueous sodium hydroxide solution to obtain AES.

Component (B3) AOS: sodium α-olefin sulfonate, trade name “Lipolan LB-840”, manufactured by Lion Corporation.

[Component (C)]
- Phenoxyethanol: Product name "Phenyl Glycol", manufactured by Nippon Nyukazai Co., Ltd.
Ethanol: Product name: "Specific Alcohol 95% Synthetic", manufactured by Japan Alcohol Sales Co., Ltd.
- Propylene glycol: Product name "Propylene Glycol", manufactured by The Dow Chemical Company.
-Butyl carbitol: Product name "Diethylene glycol monobutyl ether", manufactured by Nippon Nyukazai Co., Ltd.
- Glycerin: Product name "Glycerin", manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.

[Component (D): Protease]
D-1: Product name "Progress Uno", manufactured by Novozymes.
D-2: Product name "Coronase 48L", manufactured by Novozymes.
D-3: Trade name "Alcalase 2.5L", manufactured by Novozymes.
D-4: Product name "Everlase 16L", manufactured by Novozymes.

[Other ingredients]
・Fatty acid: coconut fatty acid. Product name: "Coconut Fatty Acid", manufactured by NOF Corporation.
Lactic acid: Product name "Sodium Lactate 60E", manufactured by Musashino Chemical Laboratory.
pTS: paratoluenesulfonic acid, trade name "PTS acid", manufactured by Kyowa Hakko Kogyo Co., Ltd.
Fragrance: Fragrance composition A described in Tables 11 to 18 of JP-A No. 2002-146399.
- Monoethanolamine: Trade name "Monoethanolamine", manufactured by Nippon Shokubai Co., Ltd.
- Water: Product name "Purified Water", manufactured by Kanto Chemical Co., Ltd.

<Examples 1 to 25>
In a 500 mL beaker, components (B) and (C) were added in the amounts shown in Tables 1 to 5 and thoroughly stirred with a magnetic stirrer (manufactured by MITAMURA KOGYO INC.) to dissolve component (B). Then, fatty acids, pTS, lactic acid, and flavorings were added and further thoroughly stirred.
Next, an appropriate amount of monoethanolamine was added so that the pH at 25°C was 7.0, followed by the addition of components (A) and (D), and then water was added so that the total amount became 100% by mass, thereby obtaining a liquid detergent composition.
Examples 1 to 21 are working examples, and Examples 22 to 25 are comparative examples.

The resulting liquid detergent compositions were evaluated for protease stability, detergency (protein), and liquid stability (low temperature) using the following evaluation methods. The results are shown in Tables 1 to 5. The amounts in the tables are in units of "mass %" and are expressed as the amount converted into pure content. A blank space for the amount means that the component was not blended (amount blended of 0 mass %).
Here, the appropriate amount of monoethanolamine refers to a necessary and sufficient amount for adjusting the pH of the liquid detergent composition at 25°C to 7.0.
The amount of water is calculated assuming that the amount of monoethanolamine is 4.0% by mass, and the actual amount of water is an amount such that the total amount (% by mass) of all ingredients, including monoethanolamine, is 100% by mass.

<Evaluation method>
[Protease stability]
After production, the liquid detergent composition of each example was stored for 2 weeks at 40° C. and 5° C. The protease activity of the liquid detergent composition stored for 2 weeks at 40° C. (40° C. stored product) and the liquid detergent composition stored for 2 weeks at 5° C. (5° C. stored product) was measured as shown below.

Milk casein (Casein, Bovine Milk, Carbohydrate and Fatty Acid Free/Calbiochem (registered trademark)) was dissolved in 1N sodium hydroxide (1 mol/L sodium hydroxide solution (1N), manufactured by Kanto Chemical Co., Ltd.), the pH was adjusted to 10.5, and the solution was diluted with an aqueous solution of 0.05M boric acid (boric acid (special grade), manufactured by Kanto Chemical Co., Ltd.) so that the concentration of milk casein became 0.6%, to prepare a protease substrate.
In addition, 0.1 g of each of the samples stored at 40° C. and 5° C. in each example was diluted 25-fold with calcium chloride (calcium chloride (special grade), manufactured by Kanto Chemical Co., Ltd.) 3° DH hard water to prepare a sample solution.

5 g of the above protease substrate was added to 1 g of sample solution, stirred for 10 seconds with a vortex mixer, and then allowed to stand at 40° C. for 30 minutes to allow the enzyme reaction to proceed. 5 g of a 0.44 M aqueous solution of TCA (trichloroacetic acid (special grade), manufactured by Kanto Chemical Co., Ltd.), an enzyme reaction stopper, was then added to the solution, and the reaction was stopped by stirring for 10 seconds with a vortex mixer. The solution was then allowed to stand at 20° C. for 30 minutes, and the precipitated unreacted substrate was removed with a 0.45 μm filter, and the filtrate was collected.
The absorbance (absorbance A) of the recovered filtrate at a wavelength of 275 nm was measured using a Shimadzu UV-160 ultraviolet-visible spectrophotometer.

In order to eliminate the influence of absorption by components other than the target component, 5 g of TCA, an enzyme reaction stopper, was added to 1 g of each sample solution, and the mixture was stirred for 10 seconds with a vortex mixer, after which 5 g of protease substrate was added, stirred for 10 seconds with a vortex mixer, and allowed to stand at 20°C for 30 minutes. Insoluble components were then removed with a 0.45 μm filter, and the filtrate was collected. The absorbance (absorbance B) of the filtrate at a wavelength of 275 nm was then measured using UV-160.
A larger difference between absorbance A and absorbance B indicates a larger amount of tyrosine (produced by the protease decomposing the protease substrate) present in the filtrate.

From the results of the above-mentioned measurement of protease activity, the residual rate (%) of protease activity was calculated according to the following formula (i).
In addition, the absorbance value at 275 nm of each filtrate substituted into the following formula (i) was used after subtracting the absorbance value at 600 nm measured at the same time in order to exclude scattered light due to bubbles, etc. from the absorbance.
Protease activity residual rate=(absorbance A of sample stored at 40° C.−absorbance B of sample stored at 40° C.)/(absorbance A of sample stored at 5° C.−absorbance B of sample stored at 5° C.)×100 (i)

Using the residual protease activity (%) as an index, enzyme stability was evaluated according to the following criteria, with ⊚, ⊚, and ◯ being deemed acceptable.
◎◎: 80% or more.
◎: 70% or more but less than 80%.
○: 60% or more but less than 70%.
△: 50% or more but less than 60%.
×: Less than 50%.

[Cleaning power (protein)]
A commercially available protein-stained cloth (manufactured by Swissatest, product name: EMPA117) cut to 5 cm x 5 cm was used as the soiled cloth. A Terg-O-tometer (manufactured by United States Testing) was used as the cleaning tester. The cleaning liquid was prepared by adding the liquid detergent composition of each example to 900 mL of water (25°C, 5° DH) so as to give a concentration of 200 ppm, and stirring for 30 seconds.

The cleaning solution, 10 of the above soiled fabrics, and the cleaned knitted fabric were placed in a cleaning tester, and washed for 10 minutes at 120 rpm and 25° C. with a bath ratio of 20. The fabrics were then transferred to a twin-tub washing machine (manufactured by Mitsubishi Electric Corporation: product name CW-C30A1-H1), dehydrated for 1 minute, rinsed in 30 L of water for 3 minutes, and air-dried.
The reflectance of the unsoiled cloth and the soiled cloth before and after cleaning was measured using a color difference meter (product name: SE7700, manufactured by Nippon Denshoku Industries Co., Ltd.), and the cleaning rate (%) was calculated according to the following formula (ii).
Cleaning rate (%)=(K/S of soiled cloth before cleaning−K/S of soiled cloth after cleaning)/(K/S of soiled cloth before cleaning−K/S of unsoiled cloth)×100 (ii)
In formula (ii), K/S is (1-R/100) ² /(2R/100), where R represents the reflectance (%) of an unsoiled cloth and a soiled cloth before and after washing.

The cleaning rate was determined for each of the 10 soiled cloths, and the average value was calculated as the cleaning rate of the liquid detergent composition. The cleaning power was then evaluated based on the following criteria, with ⊚, ⊚, and ◯ being considered as acceptable.
◎: Cleaning rate is 65% or more.
◯: cleaning rate is 60% or more but less than 65%.
△: cleaning rate is 55% or more but less than 60%.
×: cleaning rate is less than 55%.

[Liquid stability (low temperature)]
100 mL of the liquid detergent composition of each example was placed in a transparent glass bottle (wide-mouth standard bottle PS-No. 11) and sealed with a lid. After standing in this state in a thermostatic chamber at 5°C for one month, the appearance of the liquid was visually observed and evaluated according to the following criteria, with ◎, ◎, and ◯ being considered as pass.
: The liquid is fluid and transparent with no sediment observed at the bottom of the glass bottle.
⊚: The solution is fluid and a small amount of precipitate is observed at the bottom of the glass bottle, but the precipitate disappears within 15 minutes when returned to room temperature.
Good: No fluidity, slight precipitation observed at the bottom of the glass bottle, but the precipitation disappears within 15 to 30 minutes when returned to room temperature.
Δ: No fluidity, the entire liquid detergent becomes cloudy, but when returned to room temperature, the cloudiness disappears within 30 minutes to 6 hours.
×: There is no fluidity, the entire liquid detergent becomes cloudy, and the cloudiness does not disappear even when returned to room temperature.

As shown in Tables 1 to 4, all of Examples 1 to 21 were excellent in protease stability, detergency (protein), and liquid stability (low temperature).
In contrast, as shown in Table 5, Example 22, in which 5% by mass of solvent was blended, and Examples 23 to 25, in which the (AX) component was used as the nonionic surfactant, had poor protease stability and liquid stability (low temperature).

Claims (3)

Component (A): a nonionic surfactant,
(B) component: a non-soap anionic surfactant;
(D) component: Protease;
Component (C): may contain an organic solvent having a hydroxyl group,
A liquid detergent composition further comprising water ,
The content of the component (A) is 35 to 50% by mass based on the total mass of the liquid detergent composition,
The content of the (B) component is 15 to 30% by mass based on the total mass of the liquid detergent composition,
The content of the (C) component is 3 mass% or less based on the total mass of the liquid detergent composition,
The content of the (D) component is 2 to 5% by mass based on the total mass of the liquid detergent composition,
The water content is 10% by mass or more based on the total mass of the liquid detergent composition,
The total content of the (A) component and the (B) component is 50 to 70% by mass based on the total mass of the liquid detergent composition,
The component (A) contains the following component (A1):
The ratio of the content of the following component (A1) to the total content of the component (A) is 50 to 100 mass %,
The component (B) includes one or more selected from the group consisting of the following component (B1), the following component (B2), the following component (B3), and the following component (B4),
a ratio of the total content of the following component (B1), the following component (B2), the following component (B3), and the following component (B4) to the total content of the component (B) is 60 to 100 mass%;
Liquid cleaning compositions.
Component (A1): a polyoxyalkylene-type nonionic surfactant represented by the following general formula (a-1):
R ¹ -X-[(EO) _s /(AO) _t ]-(EO) _u -R ² ... (a-1)
In formula (a-1), R ¹ is a hydrocarbon group having 8 to 22 carbon atoms, -X- is a divalent linking group, and R ² is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkenyl group having 2 to 6 carbon atoms.
EO is an oxyethylene group, and s is a number from 3 to 25 indicating the average number of EO repeats.
AO is at least one of PO (oxypropylene group) and BO (oxybutylene group), t indicates the average number of repetitions of AO and is a number from 0 to 6. u indicates the average number of repetitions of EO and is a number from 0 to 20.
When t is 1 or more, the order of EO and AO in [(EO) _s /(AO) _t ] is not limited except that the terminal is not EO, and the polymer may be randomly polymerized or block polymerized. In the case of block polymerization, three or more blocks may be arranged.
However, this does not include the cases where R ¹ is a straight-chain hydrocarbon group, -X- is -O-, the carbon atom of R ¹ to which X is bonded is a primary carbon atom, R ² is a hydrogen atom, and t is 0.
Component (B1): linear alkylbenzene sulfonic acid or a salt thereof.
Component (B2): polyoxyalkylene alkyl(alkenyl) ether sulfate or a salt thereof.
Component (B3): α-olefin sulfonic acid or a salt thereof.
Component (B4): internal olefin sulfonic acid or its salt. The liquid detergent composition according to claim 1, wherein the ratio of the mass of the (A) component to the mass of the (B) component [(A)/(B)] is 1.5 to 2.5. The liquid detergent composition according to claim 1 or 2, wherein the ratio of the mass of the (C) component to the total mass of the (A) component and the (B) component [(C)/{(A)+(B)}] is 0 to 0.07.