JP7688967B2 - Liquid detergent composition and cleaning method - Google Patents

Description

The present invention relates to a liquid detergent composition and cleaning method that has high cleaning power, including the ability to remove protein stains, even when washed at high temperatures of 60°C or higher.

In particular, in commercial laundries, when washing clothes that have been worn for a long time, such as dress shirts, uniforms, kitchen lab coats, and work clothes in machine factories, which have a complex of sebum, protein, and particle stains, washing at room temperature is not sufficient to remove the stains, so high-temperature washing at 60°C or higher is used in combination with a surfactant (liquid detergent or powder detergent) and an alkaline agent.

However, if these clothes are suddenly washed at high temperatures of 60°C or higher, the protein stains will be denatured and solidified by the heat before they can be removed, making them even more difficult to remove. For this reason, a two-stage washing process was required: first, the temperature was set to room temperature to 40°C to prevent the protein stains from solidifying, and the clothes were washed in an alkaline bath, and then the washing temperature was raised to 60°C or higher to remove other stains.

However, even after performing the above two-stage cleaning, there are cases where protein stains are not sufficiently removed, or where the attached protein stains have already deteriorated due to heat or the passage of time. For this reason, detergents containing protease, a protein-degrading enzyme, are often used. However, there is an issue that when washing at temperatures above 60°C, the protease does not work effectively and the stains cannot be sufficiently removed.

Another method that can be considered is to apply a surfactant or enzyme preparation to the dirty area in advance and leave it to wash, but in commercial laundry where a large number of items need to be washed at once, this method of applying the agent to each item individually significantly reduces productivity and is inefficient.
Thus, there has been a demand for a cleaning agent that has a high ability to remove proteinaceous stains and can be used for cleaning at high temperatures of 60°C or higher without employing time-consuming methods such as two-stage cleaning or applying a cleaning component and leaving it for a while before cleaning.

For example, Patent Document 1 reports a liquid detergent composition that contains (a) 5 to 40 mass % of a nonionic surfactant represented by [R-O-(EO) _n -H] (R: alkyl or alkenyl group having 10 to 20 carbon atoms, EO: ethylene oxide, n: number of moles of ethylene oxide added) having an average added mole number of ethylene oxide of 2 to 10, (b) 0.1 to 2.0 mass % of a saturated fatty acid having 14 to 18 carbon atoms or a salt thereof calculated as saturated fatty acid, (c) a protease preparation, and (d) a citrate salt, and is substantially free of anionic surfactants other than the fatty acid salt derived from component b. Patent Document 1 examines low foaming and rinsing properties during washing, detergency for application of sebum stains at 25°C, and transparent, uniform appearance stability.

Patent Document 2 reports a liquid detergent composition containing (a) 10 to 50% by mass of a nonionic surfactant containing 6 to 15% by mass of a compound represented by R-O(AO) _n -H [wherein R is a hydrocarbon group having 8 to 22 carbon atoms, AO is an oxyalkylene group having 2 to 4 carbon atoms, and n is a number selected from 0, 1, and 2], (b) 0.5 to 10% by mass of a fatty acid having an average carbon number of 8 to 20, (c) 0.5 to 5% by mass of a chelating agent, (d) an enzyme including a protease, and (e) an enzyme stabilizer. Patent Document 2 examines the stability of the enzyme and the cleaning performance of socks at 20°C.

Patent Document 3 reports a liquid detergent containing (A) a nonionic surfactant, (B) an anionic surfactant, (C) a protease, (D) a water-soluble polymer having at least one unit selected from the group consisting of an alkylene terephthalate unit and an alkylene isophthalate unit, and at least one unit selected from the group consisting of an oxyalkylene unit and a polyoxyalkylene unit, and (E) at least one component selected from the group consisting of an α-hydroxy-monocarboxylic acid and a salt thereof, in which the total content of all the surfactants is 45% by mass or more relative to the total mass of the liquid detergent, and the content of the (B) component is 4% by mass or more relative to the total mass of the liquid detergent. Patent Document 3 examines the stability of the enzyme and the appearance stability at high concentrations of surfactants.

Patent Document 4 reports a liquid detergent composition for clothing, which is characterized by containing 36 to 70% by mass of a nonionic surfactant consisting of (A-1) an average 10 to 20 mole ethylene oxide adduct of an alcohol having a monovalent hydrocarbon group with 12 carbon atoms and (A-2) an average 10 to 20 mole ethylene oxide adduct of an alcohol having a monovalent hydrocarbon group with 13 or 14 carbon atoms, with the mass ratio of (A-1)/(A-2) being 0.1 to 4, (B) 0.1 to 2% by mass of a protease, and (C) 0.0001 to 0.01% by mass of calcium chloride. Patent Document 4 examines the stability of the enzyme and the cleaning ability of sebum stains at 20°C.

Patent Document 5 reports a liquid detergent composition for clothing that contains (a) 10 to 30 mass % of a nonionic surfactant represented by R-O-(EO) _n -H (wherein R is an alkyl or alkenyl group having 10 to 20 carbon atoms, EO is an oxyethylene group, and n is the average number of moles added which is a value in the range of 8 to 26), (b) 0.05 to 1.0 mass % of a protease enzyme, (c) an antibacterial solvent, and (d) a crosslinked carboxyvinyl polymer, and has a liquid viscosity of 50 to 1,000 mPa·s at a liquid temperature of 10 to 30° C. Patent Document 5 examines the stability of the enzyme, the viscosity of the composition, and the cleaning performance for sebum stains at 25° C.

Patent Document 6 reports a liquid detergent composition that contains: component (A): a surfactant containing 60% by mass or more of a nonionic surfactant in component (A); component (B): a homopolyamino acid and/or a salt thereof; component (C): an enzyme including a protease; and component (D): water. Patent Document 6 examines the stability of the enzyme and the cleaning ability of sebum stains at 20°C.

Patent Document 7 describes a surfactant in which component (a) is a nonionic surfactant represented by R ¹ (CO) _m O-(A ¹ O) _n -R ² (wherein R ¹ is a primary aliphatic hydrocarbon group having from 9 to 16 carbon atoms, R ² is a hydrogen atom or a methyl group, CO is a carbonyl group, m is the number 0 or 1, the A ¹ O group is one or more groups selected from an ethyleneoxy group and a propyleneoxy group, and n is the average number of moles added which is from 2 to 30). Component (b) is a polyoxyethylene alkyl ether sulfate; and component (c) is (M ^x+ ) _y SO ₄ ^2- (c1) (wherein (M ^x+ ) is one or more ions selected from a sodium ion, a potassium ion, a magnesium ion, an ammonium ion, and an alkanolammonium ion having from 2 to 6 carbon atoms. x is the valence of the ion and is the number 1 or 2. When x is 1, y is the number 2, and when x is 2, y is the number 1. ]; and a liquid detergent composition for clothing, in which the (d) component is a protease, contains water, the content of the (a) component is 5% by mass or more and 30% by mass or less, the mass ratio of the content of the (a) component to the content of the (b) component, [the content of the (b) component]/[the content of the (a) component], is 0 to 0.45, and the content of the (c) component is 0.5% by mass or more and 4% by mass or less, has been reported. Patent Document 7 examines the stability of the enzyme and the cleaning performance of protein stains at 20°C.

Patent Document 8 describes a compound in which component (a) is an alkyl sulfate ester salt having 10 to 18 carbon atoms; component (b) is R-O-(AO) _n - _SO3M (wherein R is an aliphatic hydrocarbon group having 10 to 18 carbon atoms, AO is an alkyleneoxy group selected from alkyleneoxy groups having 2 carbon atoms and alkyleneoxy groups having 3 carbon atoms, n is an integer of 1 to 20, and M is a cation). has been reported a liquid detergent composition for clothing, in which the (c) component is a nonionic surfactant, the (d) component is one or more sulfates selected from organic ammonium sulfates having 1 to 8 carbon atoms and inorganic sulfates (excluding calcium sulfate), and the (e) component is a protease, contains water, the total content of the (a) component and the (b) component is 5% by mass or more and 40% by mass or less, the (d) component is 2% by mass or more and 8% by mass or less, and the mass ratio of the (a) component to the (b) component, [the (a) component content]/[the (b) component content], is 0.5 to 10. Patent Document 8 examines the stability of the enzyme and the cleaning performance for protein stains at 30°C.

All of the cleaning compositions shown in Patent Documents 1 to 8 report compositions containing protease and a nonionic surfactant, but their cleaning power has only been examined at temperatures of about 20 to 30°C. The inventors' investigations have shown that the compositions reported in Patent Documents 1 to 8 are not sufficient in removing proteinaceous stains when washed at high temperatures of 60°C or higher.

Patent Document 9 reports that Esperase® is a protease suitable for cleaning at high temperatures, but does not disclose anything about the chelate resistance of Esperase® or its optimum temperature.

JP 2002-167600 A JP 2009-138056 A International Publication No. WO 2014/109380 JP 2004-307630 A JP 2002-327199 A International Publication No. 2011/052501 JP 2017-008135 A JP 2017-071664 A JP 2013-007049 A

The present invention aims to provide a detergent composition that exhibits high protein decomposition and high cleaning power at high temperatures of 60°C or higher.

The present inventors have found that such problems can be solved by using a liquid detergent composition for clothing containing a protease having specific properties and a nonionic surfactant, and have thus completed the present invention.
That is, the present invention is characterized in the following points.

1. A liquid detergent composition for clothing, comprising a protease (excluding Esperase (registered trademark)) having all three of the following characteristics: (1) an activity value at pH 12.0 is 85% or more of the activity value at the optimum pH; (2) an activity value when 0.2 mass% of EDTA-4Na is added is 90% or more of the activity value when no EDTA-4Na is added; and (3) an optimum temperature of 60°C or higher, and a nonionic surfactant.
2. A liquid laundry detergent composition further comprising a fatty acid or a fatty acid salt.
3. A liquid laundry detergent composition further comprising a chelating agent.
4. A cleaning method comprising cleaning clothes with the liquid detergent composition for clothing described in any one of 1 to 3 above.
5. A cleaning method in which cleaning is carried out at a temperature of 55°C or higher and under alkaline conditions.
6. A washing method, wherein the washing is carried out at a temperature of 60-80°C.
7. The washing method according to 5 or 6 above, wherein washing is carried out under conditions of pH 9 to 13.
The activity value referred to here indicates the protein decomposition ability of an enzyme (protease) under certain conditions (pH, temperature, time, etc.).

The present invention provides a composition that exhibits high proteolytic and cleaning power at high temperatures of 60°C or higher.

The present invention will be described in detail below.
The composition of the present invention contains a protease that has all three of the following characteristics: (1) an activity value at pH 12.0 that is 85% or more of the activity value at the optimum pH; (2) an activity value when 0.2 mass% of EDTA-4Na is added that is 90% or more of the activity value when no EDTA-4Na is added; and (3) an optimum temperature of 60°C or higher; and a nonionic surfactant.
Protease is a general term for peptide bond hydrolase and is widely used in detergent compositions. The protease used in the present invention must satisfy all of the following three characteristics:

The methods for determining the three characteristics that the protease contained in the composition of the present invention must satisfy will now be described in turn.
(1) The activity value at pH 12.0 is 85% or more of the activity value at the optimal pH (optimum pH)
The protease contained in the composition of the present invention maintains 85 to 100% of its activity even when used at pH 12.0, compared to the activity at the optimum pH.
This indicator defines the optimal pH as the pH at which protease activity is highest when milk casein is used as a substrate, and defines "activity at pH 12.0 being 85% or more of the activity at the optimal pH" as a protease activity at 85% or more of the activity at the optimal pH at pH = 12.0.
(2) The activity value when 0.2 mass% of EDTA-4Na is added is 90% or more of the activity value when no EDTA-4Na is added (chelate resistance).
The protease contained in the composition of the present invention has high chelate stability.
This index was determined by adding 0.2% by mass of EDTA-4Na to a solution containing 0.01% by mass of protease, and then holding the solution at pH 7.5 at 40°C for 30 minutes to measure the activity value. If the activity value was 90% or more of the activity value when no EDTA-4Na was added, the index was deemed to be "90% or more of the activity value when 0.2% EDTA-4Na was added compared to the activity value when no EDTA-4Na was added."
(3) Optimum temperature 60℃ or higher (optimum temperature)
The protease contained in the composition of the present invention exhibits high activity at temperatures of 60°C or higher.
This index was determined by measuring protease activity at various temperatures at pH 10.0 using milk casein as a substrate, and the temperature at which activity was highest was 60°C or higher, which was defined as the "optimum temperature of 60°C or higher."
The proportion of the protease in the composition may be appropriately adjusted, but from the viewpoint of cleaning properties, it is preferably 0.005 to 20% by mass, more preferably 0.5 to 15% by mass, and even more preferably 2 to 10% by mass.

Next, the type of nonionic surfactant, which is another component of the composition of the present invention, is not particularly limited as long as it can remove dirt. However, from the viewpoint of cleaning properties of cotton products, nonionic surfactants which are alkylene oxide adducts of higher alcohols and alkylene oxide adducts of alkylamines are desirable, and from the viewpoint of cleaning properties of PET products, nonionic surfactants which are alkylene oxide adducts of mono- and/or di- and/or tristyrenated phenols are preferred. These nonionic surfactants can be used alone or in combination. More preferably, a combination of an alkylene oxide adduct of higher alcohol (which may be used alone or in combination of two or more, and in the case of two or more, the sum of the values obtained by multiplying the HLB values of each by the mass ratio of each is 13 to 15) and an alkylene oxide adduct of distyrenated phenol can be exemplified.
The proportion of the nonionic surfactant in the composition is appropriately adjusted, but from the viewpoints of cleaning properties, viscosity of the composition, and ease of handling of the composition, it is preferably 0.02 to 99% by mass, more preferably 10 to 70% by mass, and even more preferably 15 to 50% by mass.

In the present invention, both components are dissolved in water (ion-exchanged water, pure water, etc.) to form a liquid composition.

The composition of the present invention may contain other components that are known in the technical field of detergents to be incorporated into detergent compositions, provided that the components do not affect the performance of the present invention.
Examples of such components include, but are not limited to, fatty acids, fatty acid salts, chelating agents, stabilizers, anionic surfactants, water-miscible organic solvents, thickeners, viscosity reducers, solubilizing agents, alkaline agents, other chelating agents, antioxidants, preservatives, other enzymes, fragrances, colorants, emulsifying agents, natural products, pH adjusters, defoamers, texture improvers, storage stability improvers, fluorescent agents, dye transfer inhibitors, redeposition inhibitors, and pearling agents.

The fatty acids and fatty acid salts mainly function as antifoaming agents. Examples of such fatty acids and fatty acid salts include fatty acids (salts) having 12 to 18 carbon atoms. Specific examples include coconut fatty acid (salts) and stearic acid (salts). They can be blended in an amount of 0.01 to 10% by mass based on the composition.
The chelating agent has a function of stabilizing each component in the composition. An example of such a chelating agent is an organic chelating agent. Specifically, an aminocarboxylic acid chelating agent (for example, EDTA, NTA, DTPA, MGDA, GLDA, HEIDA, etc.) can be used. The proportion of the chelating agent in the composition is appropriately adjusted, but from the viewpoint of antifoaming property and stability of the composition, it can be blended in an amount of 0.5 to 10% by mass relative to the blending amount of the enzyme raw material of the composition.
As the stabilizer, various types can be used, and there is no particular limitation, but examples thereof include glycol solvents such as ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, etc.; and alcohol solvents such as methanol, ethanol, propanol, butanol, benzyl alcohol, 3-methyl-3-methoxy-butanol, etc. The amount of the stabilizer in the composition can be appropriately determined depending on the purpose of use, as long as it does not impair the cleaning power of the composition of the present invention.

Next, the cleaning method will be described.
The cleaning using the composition of the present invention is suitable for cleaning so-called clothes.
Specific examples of the washing method include washing methods that involve applying physical external forces such as stirring, rotation, dropping, vibration, etc. As a specific example, the composition of the present invention can be used to wash clothes using an automatic commercial washing machine, a continuous washing machine, or a home washing machine.
The amount of the detergent composition of the present invention used in cleaning is not particularly limited and is appropriately determined for cleaning. From the viewpoint of cleaning ability and defoaming ability, it is preferable to mix the composition of the present invention in a cleaning liquid so that the protease in the detergent composition is 0.001 to 10 mass %, or the nonionic surfactant is 0.001 to 5 mass %.

The washing temperature is not particularly limited and may be appropriately determined during washing, but in order to maximize the desired effects of the composition of the present invention, washing is preferably performed at 55 to 85° C. A more preferred washing temperature is 60 to 80° C., and an even more preferred washing temperature is 70 to 80° C.
The cleaning time is not particularly limited and is appropriately determined for each cleaning step, but from the viewpoint of cleaning performance, the cleaning time is preferably 1 to 60 minutes, more preferably 3 to 30 minutes, and even more preferably 5 to 20 minutes.

The pH of the cleaning solution is preferably 8 or higher. From the viewpoint of cleaning performance and preventing embrittlement of the clothes being washed, the pH is more preferably 9 to 13, and even more preferably 10 to 12. There are no particular limitations on the method for adjusting the pH of the cleaning solution, but sodium orthosilicate, sodium metasilicate, sodium silicate No. 1, sodium silicate No. 2, sodium silicate No. 3, potassium orthosilicate, potassium metasilicate, potassium silicate No. 1, potassium silicate No. 2, potassium silicate No. 2, sodium caustic, potassium caustic, sodium carbonate, potassium carbonate, alkanolamines, sodium tripolyphosphate, etc. can be used.

When washing, for example, liquid detergents, powder detergents; various surfactants such as nonionic surfactants, anionic surfactants, cationic surfactants, and amphoteric surfactants; inorganic compounds such as silicates, carbonates, and sulfates; chelating compounds such as tripolyphosphates and aminocarboxylates; bleaching agents such as hydrogen peroxide and sodium hypochlorite; organic solvents such as alcohol-based solvents, glycol-based solvents, and hydrocarbon-based solvents; other enzymes such as proteases, lipases, amylases, and cellulases; antioxidants, preservatives, fragrances, colorants, emulsifiers, antibacterial agents, natural products, pH adjusters, defoamers, texture improvers, storage stability improvers, fluorescent agents, dye transfer inhibitors, redeposition inhibitors, soil release agents, and pearl agents may be used within a range that does not interfere with the cleaning power of the composition of the present invention. The amount of these to be added can be appropriately determined according to the purpose of use, within a range that does not interfere with the cleaning power of the composition of the present invention.

The present invention will be described in detail below with reference to examples. However, the present invention is not limited to the following description.

[Selection of protease]
Proteases include Progress UNO 100L, Esperase 8.0L, Savinase 16L, Alcalase 2.5L (all manufactured by NOVO), Clinase SAP-200L, Clinase CAP-200L, Clinase AP-200L (all manufactured by Nippon Kokken), Bioprase APL-30, Bioprase 30L (all manufactured by Nagase ChemteX), EFFECTENZ P150, PREFERENZ Using P300 (all manufactured by DuPont), and according to the following method, each protease was judged to satisfy the requirements of the present invention, namely, (1) activity value at pH 12.0 is 85% or more of the activity value at the optimal pH <optimum pH>, (2) activity value when 0.2 mass% of EDTA-4Na is added is 90% or more of the activity value when no EDTA-4Na is added <chelate resistance stability>, and (3) optimum temperature is 60°C or higher <optimum temperature>.

<(1) Optimal pH>
Various solutions with different pH values containing 0.6% by mass of milk casein as a substrate were prepared using 100 mM phosphate-sodium buffer (pH 6.0-8.0), Tris-hydrochloric acid buffer (pH 8.0-9.0), glycine-sodium hydroxide buffer (pH 9.0-10.0), boric acid-sodium hydroxide buffer (10.0-11.0) or phosphate-sodium hydroxide buffer (pH 11.0-12.0). Protease activity was measured under various pH conditions according to the enzyme activity measurement method described below. The pH condition with the highest protease activity was determined as the optimal pH for the protease. The protease activity value at pH 12 was calculated as a percentage of the protease activity value under the optimal pH condition. As a result, those with a protease activity of 85% or more were evaluated as ◯, and others were evaluated as ×.

<(2) Chelate resistance>
EDTA-4Na was added to an enzyme raw material solution diluted to 0.01% with a diluent (sodium chloride 3 g/l, calcium acetate 0.175 g/l, sodium acetate 1.667 g/l, (pH 7.5)) to give a concentration of 0.2% by mass, and the remaining protease activity after maintaining at pH 7.5 at 40°C for 30 minutes was measured according to the method for measuring enzyme activity described below. Similarly, the protease activity value in the absence of added EDTA-4Na was measured, and the ratio of the value when EDTA-4Na was added to the value when EDTA-4Na was not added was calculated. As a result, values of 90% or more were evaluated as ◯, and other values were evaluated as ×.

<(3) Optimal temperature>
A 0.6% by mass solution of milk casein adjusted to pH 10.0 with boric acid-sodium hydroxide buffer was used to determine the protease activity when reacted for 10 minutes at each temperature according to the method for measuring enzyme activity described below, and the temperature at which the activity was highest was determined as the optimum temperature. Temperatures with an optimum temperature of 60°C or higher were evaluated as ◯, and others were evaluated as ×.

<Enzyme titer>
1 ml of the enzyme raw material solution diluted to 0.01% by mass with a diluent (sodium chloride 3 g/l, calcium acetate 0.175 g/l, sodium acetate 1.667 g/l, (pH 7.5)) was added to 5 ml of the reaction solution (0.6% by mass milk casein (Merck Co., Ltd.), 0.55% by mass disodium hydrogen phosphate (pH 7.5)), and reacted at 30 ° C. for 10 minutes. After the reaction, 5 ml of trichloroacetic acid solution (trichloroacetic acid 17.97 g/l, sodium acetate anhydride 18.04 g/l, acetic acid 19.81 g/l) was added, and the mixture was left at 30 ° C. for 30 minutes, and then filtered with a membrane filter (0.45 μm). 5 ml of 0.55 M sodium carbonate and 1 ml of Folin reagent (Folin reagent: ion-exchanged water = 1:2) were added to 2 ml of the filtrate, and the mixture was left at 30 ° C. for 30 minutes, and the absorbance (660 nm) was measured. Taking the Folin color intensity (absorbance) exhibited by L-tyrosine as the standard, the enzyme activity that gave an absorbance equivalent to the absorbance exhibited by 1 μg of L-tyrosine in the entire reaction solution in 1 minute at 30° C. was defined as 1 protease unit (1 PU) to calculate the enzyme titer.

The activity value of "protease activity" referred to here indicates the protein decomposition ability of an enzyme (protease) under certain conditions (pH, temperature, time, etc.), and the enzyme titer is a unit indicating the activity value of an enzyme, expressed in PU/ml.
The results are shown in Table 1.

As shown in Table 1, of the 11 types of proteases used in the experiment, only two types, Progress UNO 100L and Esperase 8.0L, were confirmed to satisfy the following conditions: (1) activity value at pH 12.0 was 85% or more of the activity value at the optimal pH, (2) activity value with 0.2% EDTA-4Na added was 90% or more of the activity value without EDTA-4Na added, and (3) optimal temperature of 60°C or higher. The other types did not satisfy at least one of the requirements (1) to (3).

[Preparation of Composition]
A composition was prepared according to the composition (mass %) shown in Table 2.
The components used are as follows:
<Nonionic Surfactant>
・C12 alcohol EO9: Softanol 90 manufactured by Nippon Shokubai
・C12 alcohol EO12: Softanol 120, manufactured by Nippon Shokubai
・C12 alcohol EO15: Softanol 150, manufactured by Nippon Shokubai
C12 alcohol (EO1/PO2) (EO3/PO1): Manufactured by Nicca Chemical; C12 alcohol EO3 (EO1.5/PO2.5) EO1.5: Manufactured by Nicca Chemical; C12 alcohol EO3 (EO2.5/PO2.5) EO3: Manufactured by Nicca Chemical; C12 alcohol EO3 (EO3/PO2.5) EO8: Manufactured by Nicca Chemical; Distyrenated phenol EO12: Manufactured by Nicca Chemical; C18 amine EO20: Manufactured by Nicca Chemical. EO represents an ethyleneoxy group, PO represents a propyleneoxy group, and the numbers represent the number of moles added. For example, C12 alcohol (EO1/PO2) (EO3/PO1) represents a structure in which 1 mole of EO and 2 moles of PO are randomly added to an alcohol having 12 carbon atoms, and then 3 moles of EO and 1 mole of PO are randomly added, and C12 alcohol EO3 (EO1.5/PO2.5) EO1.5 represents a structure in which 3 moles of EO are added to an alcohol having 12 carbon atoms, and then 1.5 moles of EO and 2.5 moles of PO are randomly added, and finally 1.5 moles of EO are added.

<Chelating Agent>
・NTA-3Na (sodium nitrilotriacetate): Nagase ChemteX Clewat P
C-C3
EDTA-4Na (tetrasodium ethylenediaminetetraacetate): Nagase ChemteX Clewat S2
・DTPA-5Na (pentasodium diethylenetetraminepentaacetate): Nagase ChemteX Clewat DP-80
<Fatty acid>
・Coconut fatty acid: Nippon Oil & Fats Co., Ltd., coconut fatty acid ・Stearic acid: New Japan Chemical Co., Ltd., stearic acid 300
<Neutralizing agent>
・Sodium hydroxide: Liquid caustic soda made by Tokuyama

[Cleaning method]
The cleaning device used was a Tergotometer (manufactured by Daiei Scientific Instruments Co., Ltd.).
The items to be washed were a wet artificially soiled cloth (manufactured by the Laundry Science Association Foundation) and an EMPA116 soiled cloth (manufactured by the Swiss Federal Institute for Materials Testing and Research). Four pieces of the above wet artificially soiled cloth and the above EMPA116 soiled cloth cut to 4 x 5 cm were washed with 500 ml of each of the solutions of Examples 1 to 30 and Comparative Examples 1 to 6. The washing temperature was 60°C, 70°C, or 80°C, the washing time was 15 minutes, and the rotation speed was 90 rpm.

[evaluation]
<Appearance stability>
The prepared composition was placed in a 200 ml mayonnaise bottle and allowed to stand for one week in thermostatic chambers at 45° C., 25° C., and −5° C. After one week, the appearance was visually observed, and those without any sediment or precipitate were rated as ◯.
<pH>
The pH of the composition immediately after preparation was measured using a pH meter.

<Cleaning rate>
After washing, the above-mentioned wet artificially soiled cloth and EMPA116 soiled cloth were rinsed and dried, and the reflectance (550 nm) of the surface of the soiled cloth was measured using a colorimeter CM-53D (manufactured by Murakami Color Research Laboratory Co., Ltd.), and the cleaning rate was calculated using the following formula.
Cleaning rate (%) = 100 x [(reflectance after cleaning - reflectance before cleaning) / (reflectance of white cloth - reflectance before cleaning)]
The wet artificially soiled cloths were evaluated at cleaning temperatures of 60°C and 70°C. Regarding the cleaning rate of the wet artificially soiled cloths, if the average cleaning rate of four soiled cloths was less than 45%, it was marked as X, if it was 45% or more but less than 50%, it was marked as △, if it was 50% or more but less than 55%, it was marked as ○, and if it was 55% or more, it was marked as ◎, and if it was △ or more, it was marked as pass.
The EMPA116-stained cloth was evaluated at cleaning temperatures of 60°C, 70°C, and 80°C. The cleaning rate of the EMPA116-stained cloth was evaluated as follows: if the average cleaning rate of four pieces of EMPA116-stained cloth was less than 25%, it was rated as x; if it was 25% or more but less than 30%, it was rated as △; if it was 30% or more but less than 35%, it was rated as ○; if it was 35% or more, it was rated as ◎; and if it was △ or more, it was rated as pass.

<Foam loss during rinsing>
After the above cleaning test, 4 ml of the cleaning solution was taken into a mayonnaise bottle with a height of about 10 cm and a volume of about 200 ml, and the total volume was adjusted to 100 ml with water of Ca hardness 60. After sealing, the container was shaken up and down at a constant speed 40 times in 10 seconds, and immediately placed on a flat table. The foam height was measured 5 seconds after being placed still, and a foam height of less than 5 mm after 5 seconds was marked as ○, and a foam height of 5 mm or more was marked as ×.

The results are shown in Tables 2 and 3.

As shown in Table 2, all of the compositions of the present invention were excellent in appearance stability.
Furthermore, as shown in Table 3, all of the compositions of the present invention (Compositions 1 to 23) exhibited excellent cleaning performance at temperatures of 60° C. or higher in both the wet artificially soiled fabric cleaning test and the EMPA116 soiled fabric cleaning test (Examples 1 to 30).

In contrast, compositions using proteases not satisfying the requirements (1) to (3) of the present invention (compositions 24 to 29, 34 to 36) were not suitable for use at temperatures of 60°C or higher in the EMPA116-stained fabric cleaning test (Comparative Examples 1 to 6, 11 to 13). Also, compositions using an anionic surfactant instead of a nonionic surfactant together with a protease satisfying the requirements (1) to (3) of the present invention (compositions 30 and 31), a protease satisfying the requirements (1) to (3) alone (composition 33), or a nonionic surfactant alone (composition 32) showed poor cleaning performance in the wet artificially soiled fabric cleaning test or the EMPA116-stained fabric cleaning test at temperatures of 60°C or higher (Comparative Examples 7 and 8; Comparative Example 10; Comparative Example 9).

From the above results, it was confirmed that by using a composition using a protease that has all three characteristics, namely (1) an activity value at pH 12.0 of 85% or more of the activity value at the optimal pH; (2) an activity value when 0.2 mass% of EDTA-4Na is added of 90% or more of the activity value when no EDTA-4Na is added; and (3) an optimal temperature of 60°C or higher, and a nonionic surfactant, excellent cleaning power for clothing can be demonstrated.

Claims (7)

(1) the activity at pH 12.0 is 85% or more of the activity at the optimal pH;
(2) The activity value when 0.2 mass% of EDTA-4Na is added is 90% or more of the activity value when no EDTA-4Na is added;
(3) A liquid detergent composition for clothing containing a protease (excluding Esperase (registered trademark)) having all three characteristics of an optimum temperature of 60°C or higher, and a nonionic surfactant , wherein the nonionic surfactant is a combination of an alkylene oxide adduct of a higher alcohol having a Griffin HLB value of 13 to 15 (either a single type or two or more types, and in the case of two or more types, the sum of the values obtained by multiplying the HLB values of each by the mass ratio of each type should be 13 to 15) and an alkylene oxide adduct of distyrenated phenol (excluding those containing 0.05 to 3% by mass of amylase and a bicarbonate salt, or those containing amylase and one or more organic solvents selected from the group consisting of phenoxyethanol, phenoxyisopropanol, and phenyldiglycol). The liquid laundry detergent composition according to claim 1, further comprising a fatty acid or a fatty acid salt. The liquid laundry detergent composition according to claim 1 or 2, further comprising a chelating agent. A cleaning method for cleaning clothes using the liquid detergent composition for clothes according to any one of claims 1 to 3. The cleaning method according to claim 4, wherein the cleaning is carried out at a temperature of 55°C or higher and under alkaline conditions. The cleaning method according to claim 5, wherein the cleaning is carried out at a temperature of 60 to 80°C. The cleaning method according to claim 5 or 6, wherein the cleaning is carried out under conditions of pH 9.0 to 13.0.