Liquid detergent composition for laundry

Abstract

To provide a liquid detergent composition for laundry that exhibits superior detergency.SOLUTION: A liquid detergent composition for laundry comprising: (a) a surfactant [(a) component]; (b) 0.2 mass% or more and 5 mass% or less of a water-soluble neutral inorganic salt [(b) component]; and (c) 0.001 mass% or more and 0.1 mass% or less, in terms of enzyme protein amount, of an enzyme [(c) component], wherein the (a) component contains: (a1) one or more surfactants selected from polyoxyalkylene alkyl ether sulfate esters or salts thereof [(a1) component]; optionally (a2) one or more surfactants selected from anionic surfactants other than the (a1) component and nonionic surfactants [(a2) component]; and (a3) one or more surfactants selected from cationic surfactants, amphoteric surfactants, and amine-type surfactants [(a3) component]; the total content of the (a1) component and the (a2) component in the composition being 5 mass% or more and 30 mass% or less; the proportion of the (a1) component within the total content of the (a1) component and the (a2) component being 85 mass% or more; and the content of the (a3) component in the composition being 0.1 mass% or more and 5 mass% or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a liquid detergent composition for clothing. [Background technology]

[0002] In general, when using a liquid detergent composition for clothing containing an enzyme to remove partial stains (protein-containing stains such as collar stains and food stains) adhering to clothing, etc., direct application of the detergent composition, i.e., application of the detergent composition at a high concentration for a long period of time, has been effective in improving the stain removal rate. For this reason, attempts have been made to increase the viscosity of liquid detergent compositions for clothing within a range that does not cause problems in handling.

[0003] Patent Document 1 discloses a detergent composition for application to clothing, which contains 20 to 60 mass% of a surfactant and has a viscosity of 10 to 1,000 mPa·s at 20°C, and when 10 parts by mass of water is added to 100 parts by mass of the composition, the viscosity at 20°C increases by 5% or more. In the examples, combinations of a nonionic surfactant, an anionic surfactant, a cationic surfactant, an enzyme, and sodium sulfite are disclosed.

[0004] Patent Document 2 describes a cosmetic composition containing (a) 0.05 to 10 mass % of a non-soap surfactant, (b) one or more compounds selected from water-soluble fragrance compounds, and (c) 50 to 95 mass % of water, which has a pH of 7.5 to 12 at 20°C and an ionic strength of 0.5 to 5 mol m -3 The liquid detergent composition is disclosed as follows: The detergent composition has a viscosity of 1 to 50 mPa·s at 20°C (B-type viscometer, 60 r / min), and the method of use is to apply it directly to human soiling and then wash it after a certain period of time.

[0005] Patent Document 3 discloses a liquid detergent for textile products containing (A) a phenolic antibacterial agent, (B) an inorganic reducing agent, and (C) a surfactant. In the examples, a combination of an anionic surfactant, a nonionic surfactant, sodium sulfite, and a protease is disclosed.

[0006] One way to increase the viscosity of a liquid laundry detergent composition is to increase the amount of inorganic salt, such as magnesium sulfate, relative to the amount of surfactant. This increase in viscosity allows the liquid detergent composition to remain concentrated and work for a long time on localized stains. Patent Document 4 discloses a liquid laundry detergent composition containing (a) 5% to 30% by mass of surfactant, (b) an inorganic salt, and water, in which the viscosity of the diluted detergent composition, when diluted with 0.4 parts by volume of water, exceeds 1000 mPa·s at 30°C, and the viscosity (30°C) of the diluted composition is at least twice that of the undiluted composition. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-73698 [Patent Document 2] Japanese Patent Application Laid-Open No. 2004-75798 [Patent Document 3] International Publication No. 2016 / 159368 [Patent Document 4] Japanese Patent Publication No. 2022-099292 Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention provides a liquid detergent composition for clothing containing an enzyme, which exhibits high detergency when applied to remove partial stains (protein-containing stains such as collar stains and food stains) adhering to clothing, etc., and is then washed as is, and which has excellent enzyme stability. [Means for solving the problem]

[0009] The present inventors have discovered that liquid laundry detergent compositions containing specific amounts of component (a), component (b), and component (c) that meet specific requirements exhibit high detergency and enzyme stability.

[0010] That is, in one embodiment, the present invention provides a liquid detergent composition for clothing containing (a) a surfactant (hereinafter referred to as component (a)), (b) a water-soluble neutral inorganic salt (hereinafter referred to as component (b)) in an amount of 0.2% by mass to 5% by mass, and (c) an enzyme (hereinafter referred to as component (c)) in an amount of 0.001% by mass to 0.1% by mass in terms of enzyme protein, wherein component (a) contains (a1) one or more surfactants selected from polyoxyalkylene alkyl ether sulfates or salts thereof (hereinafter referred to as component (a1)), and component (a) optionally contains (a2) an anionic surfactant other than component (a1) and and one or more surfactants selected from cationic surfactants, amphoteric surfactants, and amine surfactants [hereinafter referred to as component (a3)] as component (a), wherein the total content of components (a1) and (a2) in the composition is 5% by mass or more and 30% by mass or less, the content of component (a1) in the total content of components (a1) and (a2) is 85% by mass or more, and the content of component (a3) ​​in the composition is 0.1% by mass or more and 5% by mass or less. [Effects of the Invention]

[0011] The present invention provides a liquid detergent composition for clothing with excellent detergency. Hereinafter, the detergency refers to the detergency of protein-containing stains (collar stains, food stains) adhered to clothing when the detergent composition is applied and washed, followed by washing. DETAILED DESCRIPTION OF THE INVENTION

[0012] [Liquid detergent composition for clothing] The liquid laundry detergent composition of the present invention (hereinafter also referred to simply as "the composition of the present invention") contains component (a), component (b), and component (c). In the present invention, "containing" also means that component (a), component (b), component (c), and, if necessary, optional components described below are blended and contained in the liquid laundry detergent composition. In the present invention, "content" can be read as "blended amount."

[0013] <Component (a)> The component (a) in the present invention is a surfactant. The component (a) in the present invention contains (a1) one or more surfactants selected from polyoxyalkylene alkyl ether sulfates or salts thereof (hereinafter referred to as component (a1)), optionally (a2) one or more surfactants selected from anionic surfactants and nonionic surfactants other than the (a1) (hereinafter referred to as component (a2)), and (a3) ​​one or more surfactants selected from cationic surfactants, amphoteric surfactants, and amine surfactants (hereinafter referred to as component (a3)). The component (a) in the present invention may be a surfactant consisting of components (a1), (a2), and (a3).

[0014] The component (a1) in the present invention is one or more surfactants selected from polyoxyalkylene alkyl ether sulfates or salts thereof (hereinafter also referred to as AES).

[0015] Examples of the oxyalkylene group of AES include an oxyethylene group and an oxypropylene group. From the viewpoint of improving detergency during application and cleaning, the average number of moles of the oxyalkylene group added in AES is preferably 1 or more and preferably 4 or less. From the viewpoint of improving detergency during application and cleaning, the alkyl group of AES preferably has 8 or more carbon atoms, more preferably 10 or more, and even more preferably 12 or more, and preferably has 18 or less carbon atoms, more preferably 16 or less, and even more preferably 14 or less. When AES is a salt, the counter cation of AES is preferably an alkali metal ion, and more preferably a sodium ion.

[0016] The component (a2) in the present invention is one or more surfactants selected from anionic surfactants other than AES and nonionic surfactants. The nonionic surfactants used as the component (a2) in the present invention do not include the amine surfactants of the component (a3) ​​described below.

[0017] The anionic surfactant other than AES used as component (a2) in the present invention is not particularly limited as long as it is other than AES. Specific examples include anionic surfactants having a sulfonate group, such as alkyl sulfate esters or salts thereof in which the alkyl group has 12 to 16 carbon atoms; alkenyl sulfate esters or salts thereof in which the alkenyl group has 12 to 16 carbon atoms; alkylbenzenesulfonic acids or salts thereof in which the alkyl group has 12 to 16 carbon atoms; alkenylbenzenesulfonic acids or salts thereof in which the alkenyl group has 12 to 16 carbon atoms; alkanesulfonic acids or salts thereof in which the alkane has 12 to 16 carbon atoms; α-olefinsulfonic acids or salts thereof in which the alkane has 12 to 16 carbon atoms; α-sulfofatty acids or salts thereof in which the fatty acyl group has 12 to 18 carbon atoms; and α-sulfofatty acid lower alkyl esters or salts thereof in which the fatty acyl group has 12 to 18 carbon atoms and the lower alkyl group has 1 to 3 carbon atoms. The alkyl group or alkenyl group is preferably an aliphatic alkyl group or an aliphatic alkenyl group, respectively. Specific examples of the lower alkyl group include one or more groups selected from the group consisting of a methyl group, an ethyl group, and a propyl group. The counter cation of the anionic surfactant is preferably an alkali metal ion, more preferably a sodium ion.

[0018] The nonionic surfactant used as component (a2) in the present invention is not particularly limited, but specifically, polyoxyalkylene alkyl ethers (hereinafter referred to as AE) are preferred. The average number of moles of oxyalkylene groups added in AE is preferably 2 or more, more preferably 5 or more, and even more preferably 7 or more, from the viewpoint of improving detergency during application and cleaning. Also, from the viewpoint of improving detergency during application and cleaning, it is preferably 30 or less, more preferably 20 or less, and even more preferably 15 or less. The oxyalkylene groups in AE are preferably oxyethylene groups. The alkyl groups in AE preferably have 8 or more carbon atoms, more preferably 10 or more, and even more preferably 12 or more, and preferably have 18 or less carbon atoms, more preferably 16 or less, and even more preferably 14 or less.

[0019] The component (a2) in the present invention is preferably a nonionic surfactant from the viewpoint of improving the cleaning power (against sebum stains) and ease of viscosity adjustment.

[0020] The component (a3) ​​in the present invention is one or more surfactants selected from cationic surfactants, amphoteric surfactants, and amine surfactants.

[0021] The cationic surfactant used as component (a3) ​​in the present invention is not particularly limited as long as it is a quaternary ammonium salt type cationic surfactant, but is preferably at least one selected from, for example, alkyltrimethylammonium salts having from 8 to 18 carbon atoms and alkylbenzyldimethyl quaternary ammonium salts having from 8 to 18 carbon atoms. The counter anion of the cationic surfactant is preferably an alkyl sulfate ion having from 1 to 3 carbon atoms, such as a methyl sulfate ion or an ethyl sulfate ion, or a chloride ion, with chloride ion being more preferred.

[0022] The amphoteric surfactant used as component (a3) ​​in the present invention is not particularly limited, and examples thereof include N-alkyl-N,N-dimethylamine oxide having an alkyl group with from 8 to 18 carbon atoms, N-alkylcarbonylaminopropyl-N,N-dimethylamine oxide having an alkyl group with from 8 to 18 carbon atoms, N-alkyl-N,N-dimethylaminoacetic acid betaine having an alkyl group with from 8 to 18 carbon atoms, N-alkylcarbonylaminopropyl-N,N-dimethylaminoacetic acid betaine having an alkyl group with from 8 to 18 carbon atoms, and N-alkyl-N,N-dimethyl-N-(2-hydroxysulfopropyl)ammonium sulfobetaine having an alkyl group with from 8 to 18 carbon atoms, with N-alkyl-N,N-dimethylamine oxide having an alkyl group with from 8 to 18 carbon atoms being preferred.

[0023] The amine surfactant used as component (a3) ​​in the present invention is preferably, for example, one represented by the following general formula (1): Among amine surfactants, those classified as nonionic surfactants are included in component (a3) ​​in the present invention, but are not included in component (a2) in the present invention.

[0024] [ka]

[0025] [In the formula, R 1a is an alkyl or alkenyl group having 8 to 18 carbon atoms, and R 2a O is an oxyalkylene group having 2 or 3 carbon atoms, and m and n are R 2a is the average number of moles of O added, and m+n is a number of 1 or more and 5 or less.]

[0026] In the above general formula (1), R 1a From the viewpoint of improving the cleaning power during application and cleaning, the number of carbon atoms in R is preferably 8 or more, more preferably 12 or more, and is preferably 18 or less, more preferably 14 or less. 1a R is preferably an alkyl group from the viewpoint of improving the detergency during application and cleaning.2a is preferably an oxyalkylene group having 2 carbon atoms. m+n is preferably 2 or more and 5 or less from the viewpoint of improving the detergency during application and cleaning. The amine surfactant represented by the above general formula (1) used as component (a3) ​​in the present invention is a polyoxyethylene (average number of moles of ethylene oxide added: 2.1) alkyl (C8 to C18) amine (R 1a is an alkyl group having 8 to 18 carbon atoms, R 2a is an oxyalkylene group having 2 carbon atoms, and m+n is 2.1), an amine surfactant of the above general formula (1) is more preferred.

[0027] The component (a3) ​​in the present invention is preferably one or more selected from benzalkonium chloride (C12-16), alkyl (C12-16) trimethylammonium chloride, lauryldimethylamine oxide, and polyoxyethylene (average number of moles of ethylene oxide added: 2.1) alkyl (C8-C18) amine.

[0028] <(a) Composition of ingredients> In the present invention, the amount of anionic surfactant is expressed as a value calculated by converting the counter cation of the anionic surfactant into sodium ion, and the amount of cationic surfactant is expressed as a value calculated by converting the counter anion of the cationic surfactant into chloride ion.

[0029] In the liquid detergent composition for clothing of the present invention, the content of component (a) is preferably 5.1% by mass or more, more preferably 6% by mass or more, from the viewpoint of improving the detergency during application cleaning, and is preferably 35% by mass or less, more preferably 33% by mass or less, from the viewpoint of improving the stability of the liquid detergent composition.

[0030] In the liquid detergent composition for clothing of the present invention, the content of component (a1) is preferably 5% by mass or more, more preferably 7% by mass or more, even more preferably 8% by mass or more, even more preferably 10% by mass or more, and is preferably 30% by mass or less, more preferably 25% by mass or less, and even more preferably 20% by mass or less, from the viewpoints of improving detergency during application cleaning and ease of viscosity control.

[0031] The liquid laundry detergent composition of the present invention may optionally contain component (a2). When the liquid laundry detergent composition of the present invention contains component (a2), the content of component (a2) in the composition is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and even more preferably 0.5% by mass or more, from the viewpoint of improving detergency during application cleaning, and is preferably 4.5% by mass or less, more preferably 4% by mass or less, from the viewpoint of ease of viscosity control.

[0032] In the liquid detergent composition for clothing of the present invention, the total content of the (a1) component and the (a2) component is 5% by mass or more, preferably 10% by mass or more from the viewpoint of improving detergency during application cleaning, and 30% by mass or less, preferably 20% by mass or less from the viewpoint of reducing costs.

[0033] In the liquid detergent composition for clothing of the present invention, the proportion of the content of component (a1) in the total content of component (a1) and component (a2) is 85% by mass or more, and from the viewpoint of improving the detergency during application washing, it is preferably 90% by mass or more, more preferably 93% by mass or more, and from the viewpoint of improving the detergency during application washing and the stability of the composition, it is preferably 100% by mass or less, and the proportion can also be 100% by mass.

[0034] In the liquid laundry detergent composition of the present invention, the content of component (a3) ​​is 0.1% by mass or more, preferably 0.5% by mass or more and more preferably 1% by mass or more from the viewpoint of improving detergency during application cleaning, and 5% by mass or less, preferably 2% by mass or less from the viewpoint of reducing skin irritation and improving the stability of the composition. By containing component (a3) ​​in the above range, detergency during application cleaning can be improved. Furthermore, in the liquid laundry detergent composition of the present invention, the content of component (a3) ​​is preferably within the above range and not exceeding the content of component (a1) in the composition.

[0035] In order to improve the cleaning power of the liquid detergent composition for clothing of the present invention during application cleaning, the ratio of the content of component (a1) in the content of component (a), i.e., the ratio of the content of component (a1) in the content of all surfactants contained in the composition, is preferably 80% by mass or more, more preferably 83% by mass or more, and is preferably 95% by mass or less, more preferably 90% by mass or less.

[0036] In order to improve the blend stability of the liquid detergent composition for clothing of the present invention, the total content of the (a1) component and the (a2) component relative to the content of the (a3) ​​component is preferably 2.5 or more, more preferably 5 or more, even more preferably 7 or more, and is preferably 30 or less, more preferably 20 or less, in terms of mass ratio [{(a1)+(a2)} / (a3)] in the composition.

[0037] <(b) Component> The component (b) in the present invention is a water-soluble neutral inorganic salt. In the present invention, "water-soluble" refers to a salt that dissolves in an amount of 1 g or more in 100 g of ion-exchanged water at 20° C. Furthermore, in the present invention, "neutral inorganic salt" refers to a salt with a strong acid such as hydrochloric acid or sulfuric acid and a strong base such as sodium hydroxide.

[0038] Component (b) in the present invention is preferably one or more water-soluble neutral inorganic salts selected from sodium sulfate, sodium chloride, magnesium sulfate, and magnesium chloride. In the present invention, component (b) can be contained in the liquid detergent composition for clothing by blending the water-soluble neutral inorganic salt. Furthermore, when preparing the liquid detergent composition for clothing of the present invention, a water-soluble neutral inorganic salt produced by blending a strong acid selected from hydrochloric acid and sulfuric acid with a strong base selected from sodium hydroxide and magnesium hydroxide through a neutralization reaction can also be used as component (b) in the present invention.

[0039] In one embodiment, the component (b) in the present invention is more preferably sodium sulfate from the viewpoints of reducing costs and reducing corrosiveness to metals used in some places where laundry washing operations are performed.

[0040] <(c) component> The component (c) in the present invention is an enzyme. In one embodiment, the component (c) in the present invention is preferably one or more enzymes selected from proteases, amylases, and lipases, and more preferably proteases from the viewpoint of improving detergency during application and cleaning.

[0041] The protease preferably used as component (c) in the present invention is a protease that can act in a neutral or alkaline aqueous solution. One form of component (c) in the present invention is preferably an alkaline protease, and examples of commercially available products include Progress Uno 100L manufactured by Novozymes.

[0042] From the viewpoint of improving detergency during application and cleaning, the protease used as component (c) in the present invention preferably has an activity per gram of enzyme protein, i.e., a specific activity of 5,000 mPU / g or more, more preferably 20,000 mPU / g or more. Here, 1,000 mPU is the amount of enzyme protein required to liberate a degradation product equivalent to 1 mmol of tyrosine per minute under the reaction conditions described below. The activity unit of the protease can be measured according to the following method.

[0043] [Evaluation of enzyme activity] 1.0 mL of 50 mM borate buffer (pH 10.5) containing 1% (w / v) casein (Hammerstein; Merck) was kept at 30° C. for 5 minutes, after which 0.1 mL of enzyme solution was added and the mixture was allowed to react for 15 minutes at 30° C. Next, 2.0 mL of a reaction stop solution, TCA solution (0.11 M trichloroacetic acid, 0.22 M sodium acetate, 0.33 M acetic acid), was added and the mixture was allowed to stand at room temperature for 10 minutes. After that, acid-denatured proteins were removed by filtration, and the acid-soluble protein hydrolysates contained in the filtrate were quantified by the Lowry method. Specifically, 2.5 mL of alkaline copper solution [a 1% (w / v) aqueous potassium sodium tartrate solution, a 1% (w / v) aqueous copper sulfate solution, and a 0.1 M aqueous sodium hydroxide solution of sodium carbonate (a 1:1:100 (v / v) mixture of 2% (w / v) sodium carbonate)] was added to 0.5 mL of the filtrate, and the mixture was incubated at 30°C for 10 minutes. 0.25 mL of diluted phenol reagent (phenol reagent (Kanto Chemical Co., Inc.) diluted 2-fold with ion-exchanged water) was then added, and the mixture was incubated at 30°C for 30 minutes. The absorbance at 660 nm was then measured, and the enzyme activity was calculated from the absorbance value. Note that the blank was a result of adding TCA solution, leaving the mixture at room temperature for 10 minutes, and then adding the enzyme solution.

[0044] <Composition, optional ingredients, etc.>

[0045] In the liquid laundry detergent composition of the present invention, the content of component (b) is 0.2% by mass or more, preferably 0.5% by mass or more, more preferably 1% by mass or more, from the viewpoint of controlling the viscosity and further enhancing the enzymatic stain cleanability when the liquid laundry detergent composition is applied to soiled clothing, and is 5% by mass or less, preferably 4.5% by mass or less, more preferably 4% by mass or less, from the viewpoint of improving the storage stability of the enzyme.

[0046] In the liquid detergent composition for clothing of the present invention, the content of component (c) is 0.001% by mass or more in terms of enzyme protein, and from the viewpoint of improving detergency during application washing, it is preferably 0.004% by mass or more, more preferably 0.008% by mass or more, and from the viewpoint of cost reduction, it is preferably 0.08% by mass or less, more preferably 0.05% by mass or less. The content of component (c) may be the value (enzyme protein equivalent) determined by quantifying component (c) as enzyme protein using the Lowry method.

[0047] In the liquid detergent composition for clothing of the present invention, from the viewpoint of improving detergency during application cleaning, the total content of the content of the component (a1) and the content of the component (a2) relative to the content of the component (b) is preferably 1 or more, more preferably 2 or more, even more preferably 3 or more, even more preferably 7 or more, even more preferably 15 or more, and is preferably 25 or less, more preferably 23 or less, in terms of mass ratio [{(a1)+(a2)} / (b)] in the composition.

[0048] In the liquid detergent composition for clothing of the present invention, from the viewpoint of improving the storage stability of the enzyme, the mass ratio [(b) / (c)] of the content of component (b) to the content of component (c) is preferably 20 or more, more preferably 50 or more, and is preferably 300 or less, more preferably 250 or less. The content of component (c) is expressed in terms of enzyme protein.

[0049] In the liquid detergent composition for clothing of the present invention, from the viewpoint of improving detergency during application cleaning, the mass ratio [(b) / (a3)] of the content of component (b) to the content of component (a3) ​​in the composition is preferably 0.2 or more, more preferably 0.5 or more, even more preferably 1 or more, and is preferably 20 or less, more preferably 10 or less.

[0050] The liquid detergent composition for clothing of the present invention preferably has a residence time of 60 seconds or more and 300 seconds or less as measured by the following method.

[0051] [Residence time measurement method] A cylindrical stirring bar (total length 42 mm, diameter 13 mm) was placed in a 1 L cylindrical beaker (inner diameter 105 mm), covered with a stainless steel sieve with an outer diameter of 80 mm and 2 mm mesh size, and 1 L of ion-exchanged water (30°C) was added and stirred at 600 rpm using a magnetic stirrer. The electrodes of an electrical conductivity meter (CM-42X, manufactured by DKK-TOA Corporation) were attached. A cotton knitted cloth (Tanigasashi Shoten, with a sill, 6 cm x 6 cm) was treated with 0.5 g of the liquid laundry detergent composition of the present invention dropped onto the center, and the cloth was placed in the bath (30°C) while stirring. The time when the treated cloth was placed was designated as 0 seconds, and electrical conductivity was measured every 5 seconds. The value at which electrical conductivity no longer changed was designated as the 100% dissolution value, and the 90% dissolution value was calculated. The time required to reach this 90% dissolution value was recorded as the residence time.

[0052] The liquid detergent composition for clothing of the present invention has a residence time measured by the above method of preferably 60 seconds or more, more preferably 70 seconds or more, and even more preferably 90 seconds or more, from the viewpoint of improving detergency during application-washing, and preferably 300 seconds or less, more preferably 180 seconds or less, from the viewpoint of migration of the detergent composition from the applied area. When the dissolution time is within the above range, the detergent composition can be in contact with partial soiling of clothing for a relatively long time, thereby improving detergency during application-washing.

[0053] The liquid detergent composition for clothing of the present invention may contain water. The water content in the composition is preferably 70% by mass or more, more preferably 75% by mass or more, from the viewpoint of reducing costs, and is preferably 90% by mass or less, more preferably 85% by mass or less, from the viewpoint of improving detergency during application cleaning. Water may be the remainder excluding components (a), (b), (c), and optional components.

[0054] When the liquid detergent composition for clothing of the present invention contains water, the total content of components (a), (b), (c) and water in the composition is preferably 90% by mass or more, more preferably 95% by mass or more.

[0055] The liquid detergent composition for clothing of the present invention may contain optional components other than those mentioned above, such as a foam booster, a pH adjuster which is an organic compound, a stabilizer, a fluorescent dye, a fragrance, a coloring matter, a preservative, a solvent, etc.

[0056] Examples of pH adjusters include organic alkaline compounds and organic acidic compounds. Examples of organic alkaline compounds include alkanolamines such as monoethanolamine, and further alkanolamines having 1 to 5 carbon atoms. Examples of organic acidic compounds include organic acids such as citric acid.

[0057] The pH adjuster is preferably used so that the pH of the liquid laundry detergent composition of the present invention falls within the range described below. Among the pH adjusters, the alkaline agent is preferably an alkanolamine such as monoethanolamine, from the viewpoint of improving the stability and detergency of the composition. The liquid laundry detergent composition of the present invention may contain an alkanolamine, and further monoethanolamine, in an amount of, for example, 0.2% by mass or more, further 0.4% by mass or more, and 2% by mass or less, and further 1% by mass or less. Among the pH adjusters, the acidic agent is preferably an organic acid such as citric acid, from the viewpoint of improving the stability of the composition and detergency during application washing. The liquid laundry detergent composition of the present invention may contain an organic acid, and further citric acid, in an amount of, for example, 0.05% by mass or more, further 0.1% by mass or more, and 2% by mass or less, and further 1% by mass or less.

[0058] The viscosity of the liquid laundry detergent composition of the present invention at 30°C (hereinafter also referred to as the undiluted solution viscosity) is preferably 500 mPa·s or more, more preferably 800 mPa·s or more, from the viewpoint of ease of pouring, and is preferably 8000 mPa·s or less, more preferably 5000 mPa·s or less, from the viewpoint of ease of pouring. This viscosity is measured using a B-type viscometer (TVB-10 manufactured by Toki Sangyo Co., Ltd., rotor numbers: M2 and M3, rotation speed: 12 to 60 rpm). A rotor appropriate for the viscosity is selected, and the rotation speed is adjusted according to the viscosity, so that the viscosity reading can be measured within the range of 20% to 80% of the scale width.

[0059] In order to improve the detergency during application and cleaning, and also to facilitate pouring, the liquid detergent composition for clothing of the present invention preferably has a viscosity at 30°C of a diluted product obtained by adding 10 parts by mass of water to 90 parts by mass of the composition (hereinafter also referred to as diluted viscosity) that is 5% or more higher, and more preferably 10% or more higher, than the viscosity at 30°C of the detergent composition before dilution (stock viscosity).

[0060] The liquid detergent composition for clothing of the present invention preferably has a pH of 7 or higher, more preferably 8 or higher, at 30°C from the viewpoint of improving the enzyme activity, and preferably has a pH of 11 or lower, more preferably 10 or lower, from the viewpoint of improving the stability of the composition. This pH can be measured by the method described in the Examples.

[0061] The liquid detergent composition for clothing of the present invention is suitable as a composition for application, which means that the composition is applied directly to clothing for washing.

[0062] The liquid detergent composition for clothing of the present invention exhibits a high cleaning effect when the contact time between the detergent composition and the item to be cleaned (soil) is long, and better effects can be obtained by contacting the liquid detergent composition for clothing with the soiled part of clothing for 5 to 15 minutes. Furthermore, even higher effects can be obtained by directly applying the liquid detergent composition for clothing to the soiled part of clothing and leaving it to stand for 5 to 15 minutes before contacting and immersing it in wash water. Furthermore, even higher effects can be obtained by directly applying the liquid detergent composition for clothing of the present invention to partial soiling on clothing, etc., and leaving it to stand for 5 to 15 minutes before contacting and immersing it in a cleaning solution containing the liquid detergent composition for clothing of the present invention.

[0063] The liquid detergent composition for clothing of the present invention can be directly applied to partial stains on clothing, etc., and then washed as is. Alternatively, the partial stains on clothing, etc., where the liquid detergent composition for clothing of the present invention has been applied, may be directly subjected to mechanical force, such as by hand washing, and examples thereof include a method of scrubbing the clothing with hands, a method of rubbing pieces of clothing together with hands, and a method of scrubbing the clothing with a tool such as a brush with fiber bundles implanted therein.

[0064] The present invention provides a method for washing clothes (hereinafter also referred to as the cleaning method of the present invention), in which clothes are washed with the liquid laundry detergent composition of the present invention. In the cleaning method of the present invention, the components (a), (b), (c), and water contained in the liquid laundry detergent composition of the present invention are the same as those described above for the liquid laundry detergent composition of the present invention. The cleaning method of the present invention can be appropriately applied to the embodiments described above for the liquid laundry detergent composition of the present invention.

[0065] In the cleaning method of the present invention, the liquid detergent composition for clothing of the present invention can be applied to clothing, and then the clothing can be washed. In the cleaning method of the present invention, the liquid detergent composition for clothing of the present invention can be applied to clothing, and then the applied area can be brought into contact with water to wash. Furthermore, in the cleaning method of the present invention, the liquid detergent composition for clothing of the present invention can be applied to clothing, and then the applied area can be brought into contact with water, and then mechanical force can be applied to wash.

[0066] Specifically, the present invention includes a method for washing clothes comprising the following steps 1 and 2. Step 1: Applying the liquid detergent composition for clothing of the present invention to clothing Step 2: After step 1, a step of contacting the applied area with water to wash the clothing.

[0067] In step 1, the liquid detergent composition for clothing of the present invention is preferably applied to clothing, specifically to partial stains (protein-containing stains) adhered to clothing, and then allowed to stand until the cleaning step in step 2. The contact time between the detergent composition and the item to be cleaned (soil) is preferably 5 minutes or more, more preferably 7 minutes or more, from the viewpoint of improving detergency during application and cleaning, and is preferably 30 minutes or less, more preferably 15 minutes or less, from the viewpoint of ease of the washing step.

[0068] In step 1, it is preferable to apply the liquid detergent composition for clothing of the present invention to clothing without diluting it with water or the like.

[0069] In step 2, the area of ​​the clothing to which the liquid detergent composition for clothing of the present invention has been applied is preferably brought into contact with water. For example, this can be achieved by applying the liquid detergent composition for clothing of the present invention to clothing and then contacting it with water, or by applying the liquid detergent composition for clothing of the present invention to clothing containing water. When the liquid detergent composition for clothing of the present invention is dissolved in water, the amount of water relative to the amount of the applied detergent composition is preferably at least 2 times and preferably not more than 10,000 times.

[0070] The water used in step 2 preferably has a German hardness of 0° DH or more and 30° DH or less. To achieve a more effective cleaning effect on protein-containing stains, a German hardness of 20° DH or less is more preferable, and 10° DH or less is even more preferable. The hardness refers to the total hardness determined by chelate titration using disodium ethylenediaminetetraacetic acid.

[0071] In step 2, the water to be brought into contact with the area of ​​clothing where the liquid detergent composition for clothing of the present invention has been applied can be wash water containing the liquid detergent composition for clothing of the present invention. That is, in step 2, the liquid detergent composition for clothing of the present invention can be further added within a range that does not impair the effects of the present invention. When wash water containing the liquid detergent composition for clothing of the present invention is used, the concentration of the detergent composition in the wash water is preferably 0.1 g / L or more, more preferably 0.5 g / L or more, and even more preferably 1 g / L or more, from the viewpoint of improving detergency, and is preferably 10 g / L or less, more preferably 8 g / L or less, and even more preferably 5 g / L or less, from the viewpoint of improving rinsing performance.

[0072] In step 2, the water to be brought into contact with the area of ​​the clothing where the liquid detergent composition for clothing of the present invention has been applied may contain a liquid detergent for clothing other than the detergent composition of the present invention, to the extent that the effects of the present invention are not impaired. When using wash water containing a liquid detergent for clothing other than the liquid detergent composition for clothing of the present invention, the concentration of the detergent composition in the wash water can be the same as when using wash water containing the liquid detergent composition for clothing of the present invention.

[0073] In step 2, the liquor ratio, which is the ratio of the mass of clothes (kg) to the amount of wash water (liters), i.e., the amount of wash water (liters) / mass of clothes (kg) (hereinafter, this ratio may be referred to as the liquor ratio), is preferably 5 or more, more preferably 10 or more, from the viewpoint of improving detergency, and is preferably 50 or less, more preferably 30 or less, from the viewpoint of reducing costs.

[0074] In step 2, the time for washing the clothes is preferably 3 minutes or more, more preferably 6 minutes or more, from the viewpoint of improving the cleaning power, and is preferably 60 minutes or less, more preferably 30 minutes or less, from the viewpoint of improving the cleaning efficiency.

[0075] In step 2, the temperature at which the clothes are washed is preferably 0°C or higher, more preferably 10°C or higher, and is preferably 100°C or lower, more preferably 90°C or lower, from the viewpoint of improving detergency. [Example]

[0076] Liquid laundry detergent compositions were prepared using the ingredients shown in Table 1, and the pH was adjusted to 9.0 at 30°C using citric acid monohydrate and monoethanolamine as needed. The pH was measured using the method described below. The content of each component in Table 1 is a mass-based percentage, and all values ​​are based on the active ingredient. The content of component (a1) is expressed as the sodium content, the content of cationic surfactant (component (a3)) is expressed as the chloride content, and the content of component (c) is expressed as the enzyme protein content. The resulting liquid laundry detergent compositions were evaluated as follows. The results are shown in Table 1.

[0077] <Ingredients used> Component (a1) AES (1): Polyoxyethylene (average ethylene oxide addition mole number 1) alkyl (C12-C14) ether sulfate sodium ester AES (2): Polyoxyethylene (average ethylene oxide addition mole number 2) alkyl (C12-C14) ether sulfate sodium ester (a2) component · AE(10): Polyoxyethylene (average number of moles of ethylene oxide added is 10) alkyl (C12 - C14) ether · AE(9): Polyoxyethylene (average number of moles of ethylene oxide added is 9) alkyl (C12 - C14) ether (a3) component · Benzalkonium chloride (C12 - 16) · Alkyl (C12 - 16) trimethylammonium chloride · Lauryl dimethylamine oxide · Polyoxyethylene (average number of moles of ethylene oxide added is 2.1) alkyl (C8 - C18) amine

[0078] (b) component · Sodium sulfate · Magnesium chloride · Magnesium sulfate

[0079] (c) component · Enzyme (Protease): Progress Uno 100L (Novozymes, enzyme preparation containing 10% by mass of active ingredient (equivalent amount of enzyme protein))

[0080] <Method for Measuring pH> Connect a combined electrode for pH measurement (HORIBA glass folded sleeve type) to a pH meter (HORIBA pH / Ion meter F - 23) and turn on the power. Use a saturated potassium chloride aqueous solution (3.33 mol / L) as the internal solution of the pH electrode. Next, fill 100 mL beakers with pH 4.01 standard solution (phthalate standard solution), pH 6.86 (neutral phosphate standard solution), and pH 9.18 standard solution (borate standard solution) respectively, and immerse them in a constant temperature bath at 25°C for 30 minutes. Immerse the pH measurement electrode in the standardized solution adjusted to a constant temperature for 3 minutes, and perform calibration operations in the order of pH 6.86 → pH 9.18 → pH 4.01. Adjust the sample to be measured (solution in which neutral inorganic salts are dissolved) to 25°C, immerse the electrode of the above pH meter in the sample, and measure the pH after 1 minute.

[0081] (1) Viscosity measurement of liquid laundry detergent compositions The following viscosity was measured using a Brookfield viscometer (TVB-10 manufactured by Toki Sangyo Co., Ltd., rotor numbers: M2 and M3, rotation speed: 12 to 60 rpm). Viscosity at 30°C of the liquid laundry detergent composition prepared using each component shown in Table 1 (undiluted viscosity, mPa·s) Viscosity at 30°C of the diluted product obtained by diluting 90 parts by mass of a liquid laundry detergent composition prepared using each of the components shown in Table 1 with 10 parts by mass of water (diluted viscosity, mPa·s)

[0082] (2) Calculation of residence time in a liquid laundry detergent composition by the following measurement method [Residence time measurement method] A cylindrical stirring bar (total length 42 mm, diameter 13 mm) was placed in a 1 L cylindrical beaker (inner diameter 105 mm), covered with a stainless steel sieve with an outer diameter of 80 mm and 2 mm mesh size, and 1 L of ion-exchanged water (30°C) was added and stirred at 600 rpm using a magnetic stirrer. The electrodes of an electrical conductivity meter (CM-42X, manufactured by DKK-TOA Corporation) were attached. A cotton knitted cloth (Tanigasashi Shoten, with a sill, 6 cm x 6 cm) was treated with 0.5 g of the liquid laundry detergent composition of the present invention dropped onto the center, and the cloth was placed in the bath (30°C) while stirring. The time when the treated cloth was placed was designated as 0 seconds, and electrical conductivity was measured every 5 seconds. The value at which electrical conductivity no longer changed was designated as the 100% dissolution value, and the 90% dissolution value was calculated. The time required to reach this 90% dissolution value was recorded as the residence time.

[0083] (3) Evaluation of cleaning power A standard artificially soiled cloth (product name: C-10 (base material: cotton), containing 18 mg of casein (BSA equivalent value measured by the Lowry method), peanut oil, and pigment as artificial contaminants (protein-containing soil) per gram of test cloth (obtained from Nippon Shizai Co., Ltd.) was cut into 6 cm squares. 0.3 g of the liquid detergent composition for clothing of the present invention, preheated to 30°C, was directly applied to each piece to prepare treated cloths for cleaning. 600 mL of hard water (corresponding to 10°DH on the German hardness scale) with a calcium carbonate content of 179 mg / L was added to a tergotometer and preheated to 30°C. After preparing the four treated cloths, they were immediately placed in the tergotometer and left for 5 minutes, then agitated and washed for 10 minutes (water temperature: 30°C, rotation speed: 100 rpm). The cloths were rinsed once in a washtub, spun in a spin dryer for 2 minutes, and pressed to dry, to prepare treated cloths for cleaning.

[0084] The detergency was evaluated by measuring the reflectance at 460 nm of the original fabric before soiling and before and after washing using a colorimeter (Z-300A manufactured by Nippon Denshoku Co., Ltd.), and calculating the cleaning rate (%) using the following formula. The "reflectance of original fabric" in the formula below was measured using the reflectance of the original fabric (base material: cotton) of the standard artificially soiled fabric obtained from Nippon Shizai Co., Ltd. In this evaluation, a cleaning rate of 40% or more is desirable.

[0085] Cleaning rate (%) = 100 × [(reflectance after cleaning - reflectance before cleaning) / (reflectance of original fabric - reflectance before cleaning)]

[0086] (4) Evaluation of enzyme stability The cleaning ratio was measured in the same manner as in (3) above, except that the cleaning compositions in Table 1 had been stored in a 40°C thermostatic chamber for 3 weeks. The cleaning power of the liquid laundry detergent compositions stored under the above conditions was designated "enzyme stability (cleaning ratio after storage)," and the cleaning power of the liquid laundry detergent compositions not stored under the above conditions was designated "cleaning power before storage." Liquid laundry detergent compositions with the same composition as the liquid laundry detergent compositions in Table 1 except that they did not contain component (c) (enzyme) were prepared, and the cleaning power calculated in the same manner as in (3) above was designated "cleaning power without enzyme." The cleaning power after storage was evaluated using the following formula. In this evaluation, a value calculated using the following formula of 70% or more can be said to indicate that sufficient enzyme activity remains even after storage.

[0087] Enzyme stability (%) = [(detergency after storage - detergency without enzyme) / (detergency before storage - detergency without enzyme)] x 100

[0088] [Table 1]

[0089] In Table 1, the liquid laundry detergent compositions of Examples 1 to 8 were confirmed to exhibit high detergency against artificially soiled fabrics with protein-containing soiling. This is presumably because a portion of the detergent composition, which exhibits a specific range of residence time as defined in the present invention, is able to remain on the partial soiling of the artificially soiled fabric in the wash bath. Furthermore, the liquid laundry detergent compositions of Examples 6 and 7 were confirmed to have a diluted viscosity at 30°C that was increased by 5% or more from the viscosity of the undiluted solution at 30°C.

Claims

1. (a) a surfactant (hereinafter referred to as component (a)), (b) a water-soluble neutral inorganic salt (hereinafter referred to as component (b)) in an amount of 0.2% by mass or more and 5% by mass or less; (c) an enzyme (hereinafter referred to as component (c)) in an amount of 0.001% by mass or more and 0.1% by mass or less in terms of the amount of enzyme protein; A liquid detergent composition for clothing containing The component (a) contains (a1) one or more surfactants selected from polyoxyalkylene alkyl ether sulfates or salts thereof [hereinafter referred to as component (a1)], The component (a) optionally contains (a2) one or more surfactants selected from anionic surfactants and nonionic surfactants other than the component (a1) [hereinafter referred to as component (a2)], The component (a) contains (a3) ​​one or more surfactants selected from cationic surfactants, amphoteric surfactants, and amine surfactants [hereinafter referred to as component (a3)], In the composition, the total content of the component (a1) and the component (a2) is 5% by mass or more and 30% by mass or less, The proportion of the content of the component (a1) in the total content of the component (a1) and the component (a2) is 85% by mass or more, In the composition, the content of the component (a3) ​​is 0.1% by mass or more and 5% by mass or less. Liquid detergent composition for clothing.

2. 2. The liquid detergent composition for clothing according to claim 1, which contains component (a2) as component (a).

3. 3. The liquid detergent composition for clothing according to claim 1, which contains a nonionic surfactant as component (a2) as component (a).

4. 3. The liquid detergent composition for clothing according to claim 1, wherein the residence time measured by the following method is from 60 seconds to 300 seconds. [Method for measuring residence time] A cylindrical stirring bar (total length 42 mm, diameter 13 mm) was placed in a 1 L cylindrical beaker (inner diameter 105 mm), and a stainless steel sieve with an outer diameter of 80 mm and mesh openings of 2 mm was placed on top. 1 L of ion-exchanged water (30°C) was added and stirred at 600 rpm using a magnetic stirrer. The electrodes of an electrical conductivity meter (CM-42X, manufactured by DKK-TOA Corporation) were then attached. 0.5 g of the liquid detergent composition for clothing of the present invention was dropped onto the center of a cotton knitted cloth (Tanito Shoten, with sill, 6 cm x 6 cm), and the treated cloth was placed in the stirring bath (30°C). The time when the treated cloth was placed was set to 0 seconds, and the electrical conductivity was measured at 5-second intervals. The value at which the electrical conductivity no longer changed was set to 100% dissolution, and the 90% dissolution value was calculated. The time required to reach this 90% dissolution value was defined as the residence time.

5. 3. The liquid laundry detergent composition according to claim 1, further comprising water, wherein the total content of components (a), (b), (c) and water in the composition is 90% by mass or more.

6. 3. The liquid laundry detergent composition according to claim 1, which has a viscosity at 30°C of 500 mPa·s or more and 8000 mPa·s or less.

7. 3. The liquid laundry detergent composition according to claim 1, wherein the viscosity at 30°C increases by 5% or more when 10 parts by mass of water is added to 90 parts by mass of the detergent composition.

8. 3. The liquid detergent composition for clothing according to claim 1, wherein component (b) is at least one selected from the group consisting of sodium sulfate, magnesium sulfate, and magnesium chloride.

9. 3. The liquid detergent composition for clothing according to claim 1, wherein the mass ratio of the total content of the (a1) component and the (a2) component to the content of the (a3) ​​component, [{(a1) + (a2)}] / (a3)], is 2.5 or more and 60 or less.

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