Liquid detergent composition for dishwashing machines

Abstract

To provide a liquid detergent composition for dishwashing machines that has high capability of cleaning oil stains with only a small amount of an acrylic acid polymer serving as a dispersant or a thickener blended therein, and can give a clean finish of an article having a hydrophobic surface.SOLUTION: The present invention provides a liquid detergent composition for dishwashing machines containing (a) a sulfosuccinic acid branched alkyl ester in which a branched alkyl group has 9-11 carbon atoms, (b) a thickener (excluding thickeners comprising polymers that include acrylic acid as a monomer unit), and water.SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] Examples of stains that adhere to tableware include oil stains, starch stains such as rice grains, protein stains such as eggs, and pigment stains such as tea. Of these, oil stains are difficult to remove, and there is also the problem that they re-adhere to dishes when washed in a dishwasher. In order to improve the detergency against oil stains, various proposals have been made, for example, regarding the type and formulation of surfactants, which are active cleaning ingredients. Patent Document 1 discloses a technology for an automatic dishwashing detergent containing an anionic surfactant such as a dialkyl sulfosuccinic acid. Furthermore, Patent Document 2 discloses a technology for using a dialkyl sulfosuccinic acid with a specific structure in a dishwashing detergent.

[0003] However, using a large amount of surfactant in a dishwasher detergent results in excessive foaming, overflowing the interior of the dishwasher and impairing cleaning power. Therefore, it is desirable to emulsify oil adhering to dishes using a minimal amount of surfactant. However, the dispersed oil tends to reattach to the dishes due to the low surfactant content. Therefore, a technique is commonly used in which a polymer dispersant such as polyacrylic acid is added to disperse the emulsified oil and prevent reattachment. Patent Document 3 discloses a concentrated liquid detergent composition for automatic dishwashers that contains a polycarboxylic acid polymer and prevents reattachment. Furthermore, for ease of use, liquid dishwasher detergents are thickened using thickeners, and polyacrylic acid-based thickeners are commonly used. Patent Document 4 discloses a technique containing a sulfosuccinic acid surfactant and a polycarboxylic acid thickener. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-182904 [Patent Document 2] Japanese Patent Application Publication No. 2017-214554 [Patent Document 3] Japanese Patent Application Publication No. 2019-035099 [Patent Document 4] Japanese Patent Application Laid-Open No. 2016-145306 Summary of the Invention [Problem to be solved by the invention]

[0005] When dishwasher liquid detergents containing polymer dispersants such as polyacrylic acid or polymer thickeners are used to wash items with hydrophobic surfaces, such as polypropylene, white spots may appear on the surface after washing and drying, significantly impairing the finish. The inventors have determined that these white spots are caused by a complex between calcium and an acrylic acid-based polymer. While eliminating the polymer dispersant or reducing its amount could potentially resolve this issue, omitting it would impair the dispersion of emulsified droplets, resulting in a significant decrease in cleaning power. Furthermore, reducing the amount of polymer dispersant can lead to the redeposition of oily soils on dishes during rinsing, contributing to poor finishes such as cloudiness. Dishwasher users may load more dishes into the washing cabinet than recommended, and it is desirable that cleaning effectiveness and finish quality not be compromised even in such cases.

[0006] The present invention provides a liquid detergent composition for dishwashers that has excellent detergency against oily stains and excellent finish on articles having hydrophobic surfaces, even when the blended amount of an acrylic acid-based polymer that functions as a dispersant or thickener is small. [Means for solving the problem]

[0007] The present invention relates to a liquid detergent composition for dishwashers, which contains (a) a branched alkyl sulfosuccinate ester in which the branched alkyl group has from 9 to 11 carbon atoms [hereinafter referred to as component (a)], (b) a thickener [excluding thickeners made of a polymer containing acrylic acid as a monomer unit] [hereinafter referred to as component (b)], and water. [Effects of the Invention]

[0008] According to the present invention, there is provided a liquid detergent composition for dishwashers that has excellent detergency against oily stains and excellent finish on articles having hydrophobic surfaces, even when the blended amount of an acrylic acid-based polymer that functions as a dispersant or thickener is small. DETAILED DESCRIPTION OF THE INVENTION

[0009] <Liquid detergent composition for dishwashers> The component (a) is a branched alkyl sulfosuccinate ester in which the branched alkyl group has 9 to 11 carbon atoms.

[0010] The component (a) may be a monoester or a diester, and is preferably a sulfosuccinic acid branched alkyl diester in which each of the two branched alkyl groups has from 9 to 11 carbon atoms.

[0011] The branched alkyl group of component (a) is preferably a branched alkyl group having a main chain of 6 or 7 carbon atoms and one or more side chains, the total number of carbon atoms in the side chains being 3. The branched alkyl group of component (a) is preferably a branched alkyl group selected from a 2-propylheptyl group and a 3,5,5-trimethylhexyl group.

[0012] Examples of the component (a) include branched sulfosuccinate esters represented by the following general formula (a1).

[0013] [ka]

[0014] [In the formula, R 1a , R 2a are each independently a branched alkyl group having 9 to 11 carbon atoms. 1 , A 2 are each independently an alkylene group having 2 to 4 carbon atoms, and x and y are each independently the average number of moles added, and are each independently 0 to 6. 1 is a hydrogen atom or a cation.

[0015] Further examples of the component (a) include branched alkyl sulfosuccinate esters represented by the following general formula (a1-1): This compound is a compound in which x=0 and y=0 in general formula (a1).

[0016] [ka]

[0017] [In the formula, R 1a , R 2a are each independently a branched alkyl group having 9 to 11 carbon atoms. 1 is a hydrogen atom or a cation.

[0018] The following explanation is applicable to both general formula (a1) and general formula (a1-1). R 1a , R 2a The carbon numbers of may be the same or different. In the present invention, a hydrocarbon residue obtained by removing a hydroxyl group from a secondary alcohol is included in the branched chain hydrocarbon group.

[0019] In the present invention, R 1a , R 2a Among the branched chain hydrocarbon groups, the hydrocarbon chain with the largest number of carbon atoms counting from the carbon atom bonded to the oxygen atom is the main chain, and the hydrocarbon chains that branch off from the main chain and bond to it are side chains. When two or more main chains are considered, that is, when there are two or more hydrocarbon chains with the largest number of carbon atoms (hereinafter also referred to as the longest hydrocarbon chains), the main chains are determined in the following order. 1. The side chain branching off from the longest hydrocarbon chain with the larger number of carbon atoms is considered the main chain. 2. Next, if the number of carbon atoms in the side chains branching off from the longest hydrocarbon chain is the same, the chain with the greater number of side chains branching off from the longest hydrocarbon chain is designated as the main chain. 3. Next, if the number of side chains branching off from the longest hydrocarbon chain is the same, the main chain is the one that has a side chain on the carbon atom closest to the oxygen atom, counting from the carbon atom bonded to the oxygen atom. 4. Next, if the positions of the carbon atoms having side chains closest to the oxygen atom are the same, the side chain with the larger number of carbon atoms closest to the oxygen atom is considered to be the main chain. When two or more longest hydrocarbon chains have the same symmetrical structure, either one may be used as the main chain.

[0020] R 1a , R 2a In each of the branched alkyl groups, the total number of carbon atoms constituting the side chains may be the same or different, and is preferably 3 from the viewpoint of detergency for solid grease and foam suppression. In the present invention, the total number of carbon atoms constituting the side chains refers to the total number of carbon atoms in all side chains other than the main chain in one branched alkyl group, and when there are multiple side chains, it refers to the total number of carbon atoms in all of those side chains.

[0021] R 1a , R 2a The number of side chains may be the same or different, and is 1 or more, preferably 3 or less, more preferably 2 or less, from the viewpoint of detergency for solid fats and the like and foam-suppressing property. In the present invention, the number of side chains refers to the number of side chains branching from the main chain, and the number of side chains does not change even if the side chains have further side chains branching from the side chains. However, from the viewpoint of detergency for solid grease and foam-suppressing properties, the side chains may have further side chains branching from the side chains.

[0022] R 1a , R 2aThe number of branched carbon atoms may be the same or different, and is 1 or more, preferably 3 or less, and even more preferably 2 or less, from the viewpoint of detergency and foam suppression properties for solid greases and the like. In the present invention, the number of branched carbon atoms is the total number of tertiary carbon atoms and quaternary carbon atoms in the branched chain hydrocarbon group.

[0023] R 1a , R 2a A preferred embodiment of R 1a , R 2a The total number of carbon atoms in the branched chain hydrocarbon groups is independently 9 or more and 11 or less, and further preferably 9 or 10, the number of carbon atoms in the main chain is independently 6 or 7, the number of carbon atoms in the side chains is independently 1 or more and 3 or less, and the number of side chains is independently 1.

[0024] R 1a , R 2a The specific branched alkyl groups may be the same or different, and are preferably branched alkyl groups selected from a 2-propylheptyl group and a 3,5,5-trimethylhexyl group.

[0025] In general formula (a1), A 1 , A 2 are each independently an alkylene group having 2 or more carbon atoms and 4 or less, preferably 3 or less, carbon atoms. In general formula (a1), x and y represent the average number of moles added, and from the viewpoint of detergency for solid fats and the like and foam-suppressing property, each independently is 0 or more and 6 or less, preferably 4 or less, more preferably 2 or less, and even more preferably 0. Furthermore, from the viewpoint of detergency and foam-suppressing properties for solid grease, etc., x+y is preferably 0 or more and preferably 12 or less, more preferably 6 or less, even more preferably 3 or less, and still more preferably 0.

[0026] In general formula (a1), M 1is a hydrogen ion, an inorganic cation such as a sodium ion, an ammonium ion, a potassium ion, or a magnesium ion, or an organic cation such as a monoethanolammonium ion, a diethanolammonium ion, a triethanolammonium ion, or a morpholinium ion, and is preferably an inorganic cation selected from the group consisting of a sodium ion, an ammonium ion, a potassium ion, and a magnesium ion.

[0027] In general formula (a1), R 1a , R 2a The method for preparing the compound in which R is the same is not particularly limited, but for example, it can be prepared by referring to the method described in U.S. Patent No. 2,028,091. 1a , R 2a As a method for preparing an asymmetric compound having different carbon atoms, for example, JP-A-58-24555 can be referred to. As a raw material for component (a), a compound obtained by adding an alkylene oxide to an alcohol having a predetermined number of carbon atoms can also be used. Suitable alcohols for use in producing component (a) of the present invention include: (1) Primary alcohols such as 3,5,5-trimethylhexan-1-ol and 2-propylheptan-1-ol, (2) Secondary alcohols such as 5-nonanol and 2,6-dimethyl-4-heptanol Examples include:

[0028] The liquid detergent composition for dishwashers of the present invention may contain component (a) in an amount of, for example, 0.01% by mass or more, further 0.05% by mass or more, or even 0.1% by mass or more from the viewpoint of cleaning performance, and in an amount of 10% by mass or less, further 5% by mass or less, further 3% by mass or less, or even 1% by mass or less from the viewpoint of foaming ability. In the present invention, the description of the amount of component (a) (mass %, etc.) refers to the mass of the compound converted into a sodium salt, for example, M 1 is based on the mass when it is assumed to be sodium.

[0029] Component (b) is a thickener (excluding thickeners made of polymers containing acrylic acid as a monomer unit).

[0030] The thickener (b) may be selected from water-soluble polymer thickeners and hydrogenated castor oil.

[0031] A water-soluble polymer thickener is a polymer compound that dissolves at least 1 g in 100 g of water at 25°C and has a viscosity of 100 mPa·s or more in a 1% by mass aqueous solution (B-type viscometer, rotor No. 3, 60 rpm, measurement time 1 minute, liquid temperature 25°C). The viscosity of the water-soluble polymer thickener is preferably 500 mPa·s or more, and preferably 100,000 mPa·s or less, more preferably 50,000 mPa·s or less.

[0032] Examples of the water-soluble polymer thickener include thickening polysaccharides, cellulose derivatives, and synthetic water-soluble polymers. The water-soluble polymer thickener is preferably a thickening polysaccharide or a cellulose derivative, and more preferably a thickening polysaccharide.

[0033] Examples of thickening polysaccharides include karaya gum, tragacanth gum, gum arabic, acemannan, konjac mannan, acacia gum, ghatti gum, guar gum, locust bean gum, carrageenan, xanthan gum, gellan gum, pullulan, dextran, casein, gelatin, keratin, glutelin, glucagon, gluten, zein, and shellac. Among these, thickening polysaccharides selected from carrageenan, xanthan gum, guar gum, and gellan gum are preferred, and thickening polysaccharides selected from xanthan gum and guar gum are more preferred.

[0034] Examples of cellulose derivatives include hydroxypropyl methylcellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose, hydroxypropyl cellulose, ethyl cellulose, carboxymethyl cellulose, cellulose acetate phthalate, nitrocellulose, and other cellulose ethers / esters. Among these, cellulose derivatives selected from hydroxypropyl methylcellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose, hydroxypropyl cellulose, ethyl cellulose, and carboxymethyl cellulose are preferred.

[0035] Specific examples of synthetic water-soluble polymers include polyvinyl alcohol, polyvinylpyrrolidone, polyalkylene oxide, polyacrylamide, polymethylacrylamide, polydimethylmethacrylamide, polyurethane, polyvinyl acetate, polyester, polyamide, polyamine, polyethyleneimine, copolymers of vinylpyrrolidone and vinyl acetate, and copolymers of vinylpyrrolidone and caprolactam.

[0036] The water-soluble polymer is preferably a water-soluble polymer selected from carrageenan, xanthan gum, guar gum, gellan gum, hydroxypropyl methylcellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose, hydroxypropyl cellulose, ethyl cellulose, and carboxymethyl cellulose, more preferably a water-soluble polymer selected from carrageenan, xanthan gum, guar gum, and gellan gum, even more preferably a water-soluble polymer selected from xanthan gum and guar gum, and even more preferably xanthan gum.

[0037] Furthermore, hydrogenated castor oil can be used as the hydrogenated castor oil. Taking into consideration the control of solubility in water during the preparation of the composition, polyoxyalkylene-added hydrogenated castor oil, preferably polyoxyethylene-added hydrogenated castor oil, can be used. The average number of moles of oxyalkylene, preferably oxyethylene, added in the polyoxyalkylene-added hydrogenated castor oil is, for example, 5 to 150, preferably 5 to 100. The iodine value of hydrogenated castor oil (hydrogenated castor oil) is preferably, for example, 0.1 or more, more preferably 1 or more, and 70 or less, even more preferably 50 or less (gI2 / 100g, German Einheitsmethod DGF C-V11a(53)). In the present invention, hydrogenated castor oil may be blended into the composition as a mixture containing hydrogenated castor oil and other components. Such a mixture includes, for example, a mixture containing hydrogenated castor oil, an anionic surfactant, and water, and more specifically, Mixture 2 used in producing a liquid detergent composition by the method described in JP 2016-147935 A.

[0038] Component (b) is preferably a water-soluble polymer thickener, more preferably a thickening polysaccharide, more preferably a thickening polysaccharide selected from carrageenan, xanthan gum, guar gum, and gellan gum, more preferably a thickening polysaccharide selected from xanthan gum and guar gum, and more preferably xanthan gum.

[0039] The liquid dishwasher detergent composition of the present invention may contain component (b), for example, at least 0.01% by mass, further at least 0.05% by mass, further at least 0.1% by mass, and at most 2% by mass, further at most 1% by mass, and further at most 0.8% by mass.

[0040] From the viewpoints of detergency and finish, the liquid dishwasher detergent composition of the present invention has a mass ratio (a) / (b) of the content of component (a) to the content of component (b) of preferably 0.1 or more, more preferably 0.3 or more, even more preferably 0.5 or more, still more preferably 0.7 or more, and preferably 10 or less, more preferably 7 or less, even more preferably 5 or less, still more preferably 4 or less, still more preferably 3.5 or less, and still more preferably 3 or less.

[0041] The liquid dishwasher detergent composition of the present invention may contain a surfactant other than component (a) [hereinafter referred to as component (c)]. However, some component (c) exhibits foaming properties and may impair cleaning performance, so caution is required when using it. Surfactants with hydrocarbon groups of 14 or more carbon atoms, such as alkyl groups [hereinafter referred to as component (c1)], can reduce the emulsifying power of component (a) and exhibit foaming properties, which can reduce the cleaning power. For example, nonionic surfactants with long-chain alkyl groups are themselves oily components and can impair the emulsifying power of component (a), so caution is required. Furthermore, amine compounds that function as surfactants may form complexes with component (a), reducing the effectiveness of component (a). In particular, amine compounds having a hydrocarbon group with 12 or more carbon atoms, such as an alkyl group [hereinafter referred to as component (c2)], may reduce the emulsifying power of component (a), so caution is required when using them. The liquid dishwasher detergent composition of the present invention preferably contains the components (c1) and (c2) in total at 1% by mass or less, more preferably 0.6% by mass or less, even more preferably 0.1% by mass or less, still more preferably 0.05% by mass or less, still more preferably 0.01% by mass or less, and may contain 0% by mass or more of the components (c1) and (c2).

[0042] In the present invention, when component (c) is used, a surfactant having a small number of carbon atoms in the hydrocarbon group, which is the hydrophobic group, is preferred. For example, component (c) can be selected from anionic surfactants having a hydrocarbon group with 8 to 12 carbon atoms, preferably 8 to 10 carbon atoms (excluding component (a)), and nonionic surfactants having a hydrocarbon group with 8 to 12 carbon atoms, preferably 8 to 10 carbon atoms (hereinafter referred to as component (c3)). Examples of the hydrocarbon group in component (c3) include alkyl and alkenyl groups. Specific examples of component (c3) include anionic surfactants selected from alkanesulfonic acids having from 8 to 12, preferably from 8 to 10, carbon atoms, alkyl sulfates having from 8 to 12, preferably from 8 to 10, carbon atoms, polyoxyalkylene alkyl ether sulfates having an alkyl group having from 8 to 12, preferably from 8 to 10, carbon atoms, and salts thereof, and nonionic surfactants selected from alkyl glycosides having an alkyl group having from 8 to 12, preferably from 8 to 10, carbon atoms, alkyl glyceryl ethers having an alkyl group having from 8 to 12, preferably from 8 to 10, carbon atoms, and polyoxyalkylene alkyl ethers having an alkyl group having from 8 to 12, preferably from 8 to 10, carbon atoms, and an average number of added moles of from 3 to 20, preferably from 3 to 10, oxyalkylene groups, preferably oxyethylene groups. The component (c3) is preferably an anionic surfactant selected from alkanesulfonic acids having from 8 to 12 carbon atoms, preferably from 8 to 10 carbon atoms; alkyl sulfates having from 8 to 12 carbon atoms, preferably from 8 to 10 carbon atoms; polyoxyalkylene alkyl ether sulfates having an alkyl group having from 8 to 12 carbon atoms, preferably from 8 to 10 carbon atoms; and salts thereof [hereinafter referred to as component (c3-1)]. The polyoxyalkylene alkyl ether sulfates may have an oxyalkylene group, preferably an oxyethylene group, with an average addition molar number of from 0.1 to 5, preferably from 0.5 to 2. The component (c3-1) preferably has one or more groups selected from a decyl group and a dodecyl group, more preferably a decyl group. The alkyl group or alkane moiety of the component (c3-1) preferably has 10 or 12 carbon atoms, more preferably 10.

[0043] From the viewpoint of enhancing detergency against complex soils containing grease and protein, and from the viewpoint of achieving excellent finish even under severe conditions in the presence of such complex soils, the liquid detergent composition for dishwashers of the present invention preferably contains, as component (c3), an anionic surfactant having a hydrocarbon group having from 8 to 12 carbon atoms, preferably from 8 to 10 carbon atoms, and further, as component (c3-1), one or more anionic surfactants selected from alkyl sulfate salts having an alkyl group having from 10 to 12 carbon atoms, and alkanesulfonates having an alkane moiety having from 10 to 12 carbon atoms. The liquid dishwasher detergent composition of the present invention, which contains as component (c) an anionic surfactant having a hydrocarbon group having from 8 to 12 carbon atoms, preferably from 8 to 10 carbon atoms, and further contains component (c3-1), has excellent detergency against complex soils containing grease and protein adhering to dishes, and also provides excellent post-rinsing finish even in the presence of such complex soils. It is presumed that the liquid dishwasher detergent composition of the present invention uses component (a) in combination with the anionic surfactant, for example component (c3-1), such that the anionic surfactant acts on the protein-based membrane, promoting the action of component (a) on complex soils containing protein, thereby exerting its cleaning effect against such complex soils and thereby providing excellent finish even in the presence of such complex soils. However, the manifestation of the effects of the liquid dishwasher detergent composition of the present invention is not limited to this mechanism of action.

[0044] When the liquid dishwasher detergent composition of the present invention contains component (c3), the composition may contain component (c3) in an amount of, for example, 0.01% by mass or more, further 0.05% by mass or more, further 0.1% by mass or more, and 15% by mass or less, further 10% by mass or less, or further 8% by mass or less. When the liquid dishwasher detergent composition of the present invention contains component (c3-1) as component (c), the content of component (c3-1) in the composition can also be selected from the same range.

[0045] Dishwasher detergents sometimes use a polymer containing acrylic acid as a monomer unit [hereinafter referred to as component (d)] as a dispersant. Component (d) is excluded from the thickener component (b). The liquid dishwasher detergent composition of the present invention may also contain component (d), but care must be taken with its content in terms of finished appearance. In the present invention, even if the blending amount of the polymer component (d) is small or not present, a high level of detergency against oily stains can be obtained due to the action of component (a), and the blending amount of component (d) is small or not present, resulting in excellent finished appearance of articles with hydrophobic surfaces. The component (d) may be a polymer containing acrylic acid in an amount of 30 mol % or more, and even 50 mol % or more, of all constituent monomers. Examples of component (d) include polyacrylic acid or its salts and acrylic acid-maleic acid copolymers. The weight-average molecular weight of component (d) is, for example, 1,000 or more, preferably 2,000 or more, and 70,000 or less, preferably 50,000 or less. If the weight-average molecular weight of component (d) is less than 1,000, the expected effects such as scale inhibition cannot be obtained, and if it exceeds 50,000, it is undesirable in terms of storage stability. The weight-average molecular weight of component (d) was measured by gel permeation chromatography (GPC) using polyethylene glycol of known molecular weight as a standard substance. When component (d) is a salt, it may be partially or entirely a salt, and the salt is preferably an alkali metal salt, more preferably a sodium salt or potassium salt. The liquid dishwashing detergent composition of the present invention optionally contains component (d), and the content of component (d) in the composition may be, for example, 5% by mass or less, further 3% by mass or less, further 1% by mass or less, or 0% by mass or more. The content of component (d) may also be 0% by mass.

[0046] The liquid dishwashing detergent composition of the present invention preferably contains a sequestering agent as component (e). Examples of component (e) include (e1) hydroxypolycarboxylic acids such as citric acid, malic acid, tartaric acid, and succinic acid, or their salts (hereinafter referred to as component (e1)); (e2) aminocarboxylic acids such as methylglycine diacetate, glutamic acid diacetate, hydroxyethyliminodiacetate, ethylenediaminedisuccinic acid, nitrilotriacetic acid, 1,3-propanediaminetriacetic acid, 1,3-diamino-2-hydroxypropanetetraacetic acid, glycol ether diaminetetraacetic acid, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, triethylenetetraaminehexaacetic acid, dihydroxyethylglycine, and hydroxyethylethylenediaminedicarboxymethylglutamic acid, or their salts (hereinafter referred to as component (e2)); and (e3) condensed phosphoric acids such as tripolyphosphoric acid or their salts. These components (e) may be used alone or in combination of two or more. Component (e2) is preferably an aminopolycarboxylic acid or its salt. The (e2) component is excluded from the (e1) component.

[0047] Of these, the component (e) is preferably a sequestering agent selected from citric acid, malic acid, methylglycine diacetate, glutamic acid diacetate, ethylenediaminetetraacetic acid, tripolyphosphate, and salts thereof.

[0048] From the viewpoint of enhancing the detergency for removing pigmented stains such as tea stains, the liquid dishwasher detergent composition of the present invention preferably contains component (e) as component (e1) and component (e2). In this case, the mass ratio (e1) / (e2) of the content of component (e1) to the content of component (e2) is preferably 0.1 or more, more preferably 1 or more and 10 or less. The liquid dishwasher detergent composition of the present invention preferably contains, as component (e), a hydroxy polycarboxylic acid or a salt thereof selected from citric acid and malic acid, and an amino polycarboxylic acid or a salt thereof selected from methylglycine diacetic acid, glutamic acid diacetic acid, and ethylenediaminetetraacetic acid.

[0049] The liquid dishwasher detergent composition of the present invention contains component (e) in an amount of preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 1% by mass or more, and even more preferably 3% by mass from the viewpoint of cleaning performance, and preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less from the viewpoint of formulation stability.

[0050] In the present invention, it is preferable to contain an antifoaming agent as component (f) from the viewpoint of foam suppression. From the viewpoint of blending suitability, the component (f) is preferably one or more selected from polyalkylene glycols having alkylene oxides of 3 or 4 carbon atoms as monomer units and silicone compounds. These can also be used in combination.

[0051] Examples of the polyalkylene glycol having an alkylene oxide of 3 or 4 carbon atoms as a monomer unit, which is the component (f), include polypropylene glycol and polybutylene glycol, with polypropylene glycol being preferred. The number average molecular weight of the polyalkylene glycol having alkylene oxides of 3 or 4 carbon atoms as monomer units is preferably 1,000 or more, more preferably 1,500 or more, even more preferably 2,000 or more, from the viewpoint of suppressing foaming during use, and is preferably 20,000 or less, more preferably 10,000 or less, even more preferably 6,000 or less, and even more preferably 4,000 or less. The number average molecular weight can be determined from the hydroxyl value. The hydroxyl value can be measured by a method in accordance with JIS K-1557-1.

[0052] The silicone compound of component (f) may be in the form of an oil, solution, powder, emulsion, or the like, but is not limited thereto. Examples include polyorganosiloxane oils such as polydimethylsiloxane, dispersions of polyorganosiloxane resins, emulsions of polyorganosiloxane, and combinations of polyorganosiloxanes chemically adsorbed or fused onto silica and silica particles. Among these, polydimethylsiloxane is a preferred example of component (f).

[0053] The liquid dishwasher detergent composition of the present invention contains component (f) in an amount of preferably 0.1% by mass or more, more preferably 0.15% by mass or more, from the viewpoint of defoaming or foam-suppressing properties, and preferably 5% by mass or less, more preferably 4% by mass or less, and even more preferably 3% by mass or less, from the viewpoint of storage stability.

[0054] The dishwasher detergent composition of the present invention may further contain, as optional components, components such as a solvent, a hydrotrope agent, an alkaline agent, a pH adjuster, a viscosity adjuster, a fragrance, a colorant, an antioxidant, a preservative, a foam suppressor, a bleaching agent, a bleach activator, a rust inhibitor, and an enzyme.

[0055] The liquid detergent composition for dishwashers of the present invention contains water. The water content may be, for example, 50% by mass or more, or even 70% by mass or more, and 95% by mass or less, or even 90% by mass or less, of the composition.

[0056] From the viewpoint of irritation to the skin of hands, the liquid dishwasher detergent composition of the present invention has a pH at 25°C of preferably 2 or more, more preferably 4 or more, even more preferably 5 or more, and preferably 10 or less, more preferably 9 or less, even more preferably 8 or less. The pH can be measured by a glass electrode method.

[0057] The liquid dishwasher detergent composition of the present invention has a viscosity at 25°C of preferably 3 mPa·s or more, more preferably 10 mPa·s or more, and preferably 5,000 mPa·s or less, more preferably 2,500 mPa·s or less, although this may vary depending on the intended use. The viscosity can be adjusted using commonly used thickeners, solvents, hydrotropes, etc. The viscosity of the liquid dishwasher detergent composition of the present invention can be measured using a Brookfield viscometer with a No. 2 rotor at 6 rpm for 1 minute at a liquid temperature of 25°C.

[0058] The liquid detergent composition for dishwashers of the present invention is preferably used by diluting the composition with water, for example, 10 times or more but less than 10,000 times, or even 50 times or more but less than 5,000 times, to prepare a cleaning liquid, which is then used for cleaning.

[0059] From the viewpoint of detergency, the dishwasher detergent composition of the present invention has a pH at 25°C of a 0.2% by mass water dilution (corresponding to a 500-fold dilution) of preferably 5 or more, more preferably 5.5 or more, even more preferably 6 or more, and preferably 11 or less, more preferably 10 or less, even more preferably 9 or less. The pH can be measured by a glass electrode method.

[0060] The washing temperature when using the liquid dishwasher detergent composition of the present invention is not particularly limited, but can be selected from, for example, 10°C or higher, more preferably 20°C or higher, and 100°C or lower, further preferably 90°C or lower, and even more preferably 60°C or lower, from the viewpoint of detergency and anti-redeposition properties based on the ability to disperse dirt. When using the liquid dishwasher detergent composition of the present invention in a dishwasher, for example, a commercially available dishwasher, the temperature during washing is preferably 40°C or higher, more preferably 55°C or higher, and preferably 90°C or lower, more preferably 80°C or lower. Furthermore, when using the liquid dishwasher detergent composition of the present invention in a dishwasher, for example, a commercially available dishwasher, the temperature during rinsing is preferably 50°C or higher, more preferably 65°C or higher, and preferably 90°C or lower, more preferably 80°C or lower.

[0061] The hardness of the water used for dilution when using the liquid dishwasher detergent composition of the present invention is preferably 0° DH or more, more preferably 2° DH or more, and preferably 20° DH or less, more preferably 10° DH or less, and even more preferably 8° DH or less, on the German hardness scale.

[0062] The liquid dishwasher detergent composition of the present invention is used for washing dishes in a dishwasher. Examples of tableware include items used to hold food, such as plates, bowls, and cups, and items used to serve food, such as chopsticks, forks, knives, and spoons. In the present invention, tableware may also refer to items that come into contact with food and their parts that can be washed in a dishwasher, such as storage containers such as Tupperware and bottles, cooking utensils such as knives, cutting boards, pots, frying pans, and fish grills, and cooking appliances such as food processors and mixers. Examples of materials for tableware include plastics (including silicone resins), metals, ceramics, wood, and combinations thereof. The liquid dishwasher detergent composition of the present invention is suitable for washing tableware with hydrophobic surfaces, such as plastic tableware. Washing using the liquid dishwasher detergent composition of the present invention is similar to washing using a conventional dishwasher.

[0063] The present invention provides a method for washing dishes in a dishwasher using a washing liquid containing the liquid dishwasher detergent composition of the present invention and water (hereinafter also referred to as the washing method of the present invention).The washing method of the present invention may be a method for washing dishes using a washing liquid containing component (a), component (b), and water.The washing liquid may be obtained by diluting the liquid dishwasher detergent composition of the present invention with water, for example, 10 to 10,000 times.The washing liquid may be obtained by mixing the liquid dishwasher detergent composition of the present invention with water having the German hardness.

[0064] The concentration of the component (a) in the cleaning solution may be, for example, 1 ppm or more, further 3 ppm or more, further 5 ppm or more, and 1000 ppm or less, further 500 ppm or less, further 100 ppm or less.

[0065] The concentration of the component (b) in the cleaning liquid may be, for example, 1 ppm or more, further 2 ppm or more, further 5 ppm or more, and 500 ppm or less, further 100 ppm or less, further 50 ppm or less.

[0066] The cleaning solution preferably contains component (c3) and also component (c3-1). The concentration of component (c3) in the cleaning solution may be, for example, 10 ppm or more, further 20 ppm or more, further 30 ppm or more, and 2000 ppm or less, further 1000 ppm or less, or further 500 ppm or less. Furthermore, when the cleaning solution contains component (c3-1) as component (c), the concentration of component (c3-1) in the cleaning solution can also be selected from this range.

[0067] From the viewpoint of detergency, the pH of the cleaning solution is preferably 5 or more, more preferably 5.5 or more, even more preferably 6 or more, and preferably 11 or less, more preferably 10 or less, even more preferably 9 or less. The pH can be measured by a glass electrode method. The pH of the cleaning solution is the pH at the temperature during cleaning, but may be the pH at 25°C.

[0068] The cleaning solution has a temperature of preferably 40°C or higher, more preferably 55°C or higher, and preferably 90°C or lower, more preferably 80°C or lower.

[0069] In the cleaning method of the present invention, after cleaning with the cleaning solution, rinsing with water can be performed. The temperature of the water used for rinsing is preferably 50°C or higher, more preferably 65°C or higher, and preferably 90°C or lower, more preferably 80°C or lower.

[0070] In the cleaning method of the present invention, the tableware may be tableware having dirt including oily dirt attached thereto. The cleaning method of the present invention can suppress the redeposition of dirt on tableware, for example, tableware having a hydrophobic surface.

[0071] <Aspects of the present invention> The following are examples of embodiments of the present invention. The matters described in relation to the liquid detergent composition for dishwashers and the method for cleaning hard articles of the present invention can be applied as appropriate to these embodiments.

[0072] <1> A liquid detergent composition for dishwashers, comprising: (a) a branched alkyl sulfosuccinate ester in which the branched alkyl group has from 9 to 11 carbon atoms [hereinafter referred to as component (a)]; (b) a thickener [excluding thickeners made of a polymer containing acrylic acid as a monomer unit] [hereinafter referred to as component (b)]; and water.

[0073] <2> The branched alkyl group of component (a) is a branched alkyl group having a main chain of 6 or 7 carbon atoms and one or more side chains, the total number of carbon atoms in the side chains being 3, <1> The liquid detergent composition for dishwashers according to claim 1.

[0074] <3> The branched alkyl group of component (a) is a branched alkyl group selected from a 2-propylheptyl group and a 3,5,5-trimethylhexyl group. <1> or <2> The liquid detergent composition for dishwashers according to claim 1.

[0075] <4> The component (a) is a branched sulfosuccinate ester represented by the following general formula (a1): <1> ~ <3> 10. The liquid detergent composition for dishwashers according to claim 9, wherein the detergent is a liquid detergent composition for dishwashers.

[0076] [ka]

[0077] [In the formula, R 1a , R 2a are each independently a branched alkyl group having 9 to 11 carbon atoms. 1 , A 2 are each independently an alkylene group having 2 to 4 carbon atoms, and x and y are each independently the average number of moles added, and are each independently 0 to 6. 1 is a hydrogen atom or a cation.

[0078] <5> In general formula (a1), R 1a , R 2a are each 1 or more, and preferably 3 or less, more preferably 2 or less, <4> The liquid detergent composition for dishwashers according to claim 1.

[0079] <6> In general formula (a1), R 1a , R 2a The number of branched carbon atoms in each of the above is 1 or more, and preferably 3 or less, more preferably 2 or less. <4> or <5> The liquid detergent composition for dishwashers according to claim 1.

[0080] <7> In general formula (a1), R 1a , R 2a the total number of carbon atoms in the branched chain hydrocarbon groups is independently 9 or 10, the number of carbon atoms in the main chain is independently 6 or 7, the number of carbon atoms in the side chains is independently 1 or more and 3 or less, and the number of side chains is independently 1, <4> ~ <6> 10. The liquid detergent composition for dishwashers according to claim 9, wherein the detergent is a liquid detergent composition for dishwashers.

[0081] <8> In general formula (a1), R 1a , R 2a are branched alkyl groups selected from a 2-propylheptyl group and a 3,5,5-trimethylhexyl group, <4> ~ <7> 10. The liquid detergent composition for dishwashers according to claim 9, wherein the detergent is a liquid detergent composition for dishwashers.

[0082] <9> In the general formula (a1), x and y each independently represent 0. <4> ~ <8> 10. The liquid detergent composition for dishwashers according to claim 9, wherein the detergent is a liquid detergent composition for dishwashers.

[0083] <10> In general formula (a1), M 1 is an inorganic cation selected from sodium ions, ammonium ions, potassium ions, and magnesium ions; <4> ~ <9> 10. The liquid detergent composition for dishwashers according to claim 9, wherein the detergent is a liquid detergent composition for dishwashers.

[0084] <11> The component (a) is a sulfosuccinic acid branched alkyl diester, wherein each of the two branched alkyl groups has 9 to 11 carbon atoms. <1> ~ <10> 10. The liquid detergent composition for dishwashers according to claim 9, wherein the detergent is a liquid detergent composition for dishwashers.

[0085] <12> (a) component is contained in an amount of 0.01% by mass or more, further 0.05% by mass or more, further 0.1% by mass or more, and 10% by mass or less, further 5% by mass or less, further 3% by mass or less, further 1% by mass or less, <1> ~ <11> 10. The liquid detergent composition for dishwashers according to claim 9, wherein the detergent is a liquid detergent composition for dishwashers.

[0086] <13> The component (b) is a thickener selected from a water-soluble polymer thickener and hydrogenated castor oil. <1> ~ <12> 10. The liquid detergent composition for dishwashers according to claim 9, wherein the detergent is a liquid detergent composition for dishwashers.

[0087] <14> The water-soluble polymer thickener is a water-soluble polymer selected from thickening polysaccharides, cellulose derivatives, and synthetic water-soluble polymers. <13> The liquid detergent composition for dishwashers according to claim 1.

[0088] <15> The thickening polysaccharide is a thickening polysaccharide selected from carrageenan, xanthan gum, guar gum, and gellan gum, and is further a thickening polysaccharide selected from xanthan gum and guar gum. <14> The liquid detergent composition for dishwashers according to claim 1.

[0089] <16> The cellulose derivative is selected from hydroxypropylmethylcellulose, hydroxymethylcellulose, hydroxyethylcellulose, methylcellulose, hydroxypropylcellulose, ethylcellulose, and carboxymethylcellulose. <14> or <15> The liquid detergent composition for dishwashers according to claim 1.

[0090] <17> the synthetic water-soluble polymer is selected from polyvinyl alcohol, polyvinylpyrrolidone, polyalkylene oxide, polyacrylamide, polymethylacrylamide, polydimethylmethacrylamide, polyurethane, polyvinyl acetate, polyester, polyamide, polyamine, polyethyleneimine, a copolymer of vinylpyrrolidone and vinyl acetate, and a copolymer of vinylpyrrolidone and caprolactam; <14> ~ <16> 10. The liquid detergent composition for dishwashers according to claim 9, wherein the detergent is a liquid detergent composition for dishwashers.

[0091] <18> The hydrogenated castor oil is polyoxyethylene-added hydrogenated castor oil. <13> ~ <17> 10. The liquid detergent composition for dishwashers according to claim 9, wherein the detergent is a liquid detergent composition for dishwashers.

[0092] <19> The component (b) is a water-soluble polymer thickener, further a thickening polysaccharide, further a thickening polysaccharide selected from carrageenan, xanthan gum, guar gum, and gellan gum, further a thickening polysaccharide selected from xanthan gum and guar gum, further xanthan gum; <13> ~ <18> 10. The liquid detergent composition for dishwashers according to claim 9, wherein the detergent is a liquid detergent composition for dishwashers.

[0093] <20> (b) component in an amount of 0.01% by mass or more, further 0.05% by mass or more, further 0.1% by mass or more, and 2% by mass or less, further 1% by mass or less, further 0.8% by mass or less; <1> ~ <19> 10. The liquid detergent composition for dishwashers according to claim 9, wherein the detergent is a liquid detergent composition for dishwashers.

[0094] <21> the total content of surfactants having a hydrocarbon group having 14 or more carbon atoms, for example, an alkyl group, and amine compounds having a hydrocarbon group having 12 or more carbon atoms, for example, an alkyl group, and further the total content of nonionic surfactants having a hydrocarbon group having 14 or more carbon atoms, for example, an alkyl group, and amine compounds having a hydrocarbon group having 12 or more carbon atoms, for example, an alkyl group, in the composition is preferably 1% by mass or less, more preferably 0.6% by mass or less, even more preferably 0.1% by mass or less, still more preferably 0.05% by mass or less, still more preferably 0.01% by mass or less, and is 0% by mass or more, or 0% by mass; <1> ~ <20> The liquid detergent composition for dishwashers according to claim 1.

[0095] <22> The composition contains a surfactant selected from an anionic surfactant having a hydrocarbon group with 8 to 12 carbon atoms, preferably 8 to 10 carbon atoms (excluding component (a)), and a nonionic surfactant having a hydrocarbon group with 8 to 12 carbon atoms, preferably 8 to 10 carbon atoms (hereinafter referred to as component (c3)), <1> ~ <21> 10. The liquid detergent composition for dishwashers according to claim 9, wherein the detergent is a liquid detergent composition for dishwashers.

[0096] <23> the anionic surfactant of component (c3) is an anionic surfactant selected from alkanesulfonic acids having from 8 to 12 carbon atoms, preferably from 8 to 10 carbon atoms, alkyl sulfates having from 8 to 12 carbon atoms, preferably from 8 to 10 carbon atoms, polyoxyalkylene alkyl ether sulfates having an alkyl group having from 8 to 12 carbon atoms, preferably from 8 to 10 carbon atoms, and salts thereof [hereinafter referred to as component (c3-1)]; <22> The liquid detergent composition for dishwashers according to claim 1.

[0097] <24> The component (c3-1) has one or more groups selected from a decyl group and a dodecyl group, and further has a decyl group; <23> The liquid detergent composition for dishwashers according to claim 1.

[0098] <25> the nonionic surfactant of component (c3) is a nonionic surfactant selected from alkyl glycosides having an alkyl group with 8 to 12 carbon atoms, preferably 8 to 10 carbon atoms, alkyl glyceryl ethers having an alkyl group with 8 to 12 carbon atoms, preferably 8 to 10 carbon atoms, and polyoxyalkylene alkyl ethers having an alkyl group with 8 to 12 carbon atoms, preferably 8 to 10 carbon atoms, and an oxyalkylene group, preferably oxyethylene group, with an average addition molar number of 3 to 20, preferably 3 to 10; <22> ~ <24> 10. The liquid detergent composition for dishwashers according to claim 9, wherein the detergent is a liquid detergent composition for dishwashers.

[0099] <26> (c3) component is contained in an amount of 0.01% by mass or more, further 0.05% by mass or more, further 0.1% by mass or more, and 15% by mass or less, further 10% by mass or less, further 8% by mass or less. <22> ~ <25> 10. The liquid detergent composition for dishwashers according to claim 9, wherein the detergent is a liquid detergent composition for dishwashers.

[0100] <27> The content of the polymer containing acrylic acid as a monomer unit in the composition is 5% by mass or less, further 3% by mass or less, further 1% by mass or less, and further 0% by mass or more. <1> ~ <26> 10. The liquid detergent composition for dishwashers according to claim 9, wherein the detergent is a liquid detergent composition for dishwashers.

[0101] <28> The composition contains, as the component (e), a sequestering agent, and further contains a sequestering agent selected from (e1) a hydroxy polycarboxylic acid or a salt thereof (hereinafter referred to as the component (e1)), (e2) an aminocarboxylic acid or a salt thereof (hereinafter referred to as the component (e2)), and (e3) a condensed phosphoric acid or a salt thereof, and further contains a sequestering agent selected from citric acid, malic acid, methylglycine diacetate, glutamic acid diacetate, ethylenediaminetetraacetic acid, tripolyphosphate, and salts thereof, <1> ~ <27> 10. The liquid detergent composition for dishwashers according to claim 9, wherein the detergent is a liquid detergent composition for dishwashers.

[0102] <29> The component (e) contains the component (e1) and the component (e2), and the mass ratio (e1) / (e2) of the content of the component (e1) to the content of the component (e2) is 0.1 or more, further 1 or more, and 10 or less; <28> The liquid detergent composition for dishwashers according to claim 1.

[0103] <30> The content of component (e) is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 1% by mass or more, still more preferably 3% by mass, and preferably 20% by mass or less, more preferably 15% by mass or less, even more preferably 10% by mass or less. <29> or <28> The liquid detergent composition for dishwashers according to claim 1.

[0104] <31> (f) contains an antifoaming agent as a component, and further contains at least one selected from polyalkylene glycols having alkylene oxides having 3 or 4 carbon atoms as monomer units, and silicone compounds; <1> ~ <30> 10. The liquid detergent composition for dishwashers according to claim 9, wherein the detergent is a liquid detergent composition for dishwashers.

[0105] <32> The polyalkylene glycol of component (f) is polypropylene glycol, and the number average molecular weight of the polypropylene glycol is preferably 1,000 or more, more preferably 1,500 or more, even more preferably 2,000 or more, and is preferably 20,000 or less, more preferably 10,000 or less, even more preferably 6,000 or less, and even more preferably 4,000 or less. <31> The liquid detergent composition for dishwashers according to claim 1.

[0106] <33> The silicone compound of component (f) is selected from polyorganosiloxane oil, a dispersion of polyorganosiloxane resin, an emulsion of polyorganosiloxane, and a combination of polyorganosiloxane and silica particles in which the polyorganosiloxane is chemically adsorbed or fused onto the silica. <31> or <32> The liquid detergent composition for dishwashers according to claim 1.

[0107] <34> The content of component (f) is preferably 0.1% by mass or more, more preferably 0.15% by mass or more, and preferably 5% by mass or less, more preferably 4% by mass or less, and even more preferably 3% by mass or less. <31> ~ <33> 10. The liquid detergent composition for dishwashers according to claim 9, wherein the detergent is a liquid detergent composition for dishwashers.

[0108] <35> The pH of the liquid dishwashing detergent composition at 25°C is preferably 2 or more, more preferably 4 or more, even more preferably 5 or more, and preferably 10 or less, more preferably 9 or less, even more preferably 8 or less. <1> ~ <34> 10. The liquid detergent composition for dishwashers according to claim 9, wherein the detergent is a liquid detergent composition for dishwashers.

[0109] <36> The viscosity of the liquid dishwashing detergent composition at 25°C is preferably 3 mPa·s or more, more preferably 10 mPa·s or more, and preferably 5,000 mPa·s or less, more preferably 2,500 mPa·s or less. <1> ~ <35> 10. The liquid detergent composition for dishwashers according to claim 9, wherein the detergent is a liquid detergent composition for dishwashers.

[0110] <37> The mass ratio (a) / (b) of the content of the component (a) to the content of the component (b) is preferably 0.1 or more, more preferably 0.3 or more, even more preferably 0.5 or more, still more preferably 0.7 or more, and is preferably 10 or less, more preferably 7 or less, even more preferably 5 or less, still more preferably 4 or less, still more preferably 3.5 or less, and still more preferably 3 or less. <1> ~ <36> 10. The liquid detergent composition for dishwashers according to claim 9, wherein the detergent is a liquid detergent composition for dishwashers.

[0111] <38> In the dishwasher, <1> ~ <37> 10. A method for washing tableware, comprising washing tableware with a cleaning liquid containing the liquid detergent composition for a dishwasher according to any one of 1 to 9 above and water.

[0112] <39> The concentration of the component (a) in the cleaning solution is 1 ppm or more, further 3 ppm or more, further 5 ppm or more, and 1000 ppm or less, further 500 ppm or less, further 100 ppm or less, <38> The cleaning method described in

[0113] <40> The temperature of the cleaning solution is 40°C or higher, preferably 55°C or higher, and preferably 90°C or lower, more preferably 80°C or lower. <38> or <39> The cleaning method described in

[0114] <41> The cleaning liquid is prepared by diluting the liquid detergent composition for dishwashers with water by 10 times or more but less than 10,000 times, or further by 50 times or more but less than 5,000 times. <38> ~ <40> 10. The cleaning method according to claim 9, wherein the cleaning agent is a fluorine-containing compound.

[0115] <42> Tableware includes articles that come into contact with food and can be washed in a dishwasher, and also includes articles and parts thereof selected from plates, bowls, cups, chopsticks, forks, knives, spoons, Tupperware, bottles, kitchen knives, cutting boards, pots, frying pans, fish grills, food processors, and mixers. <38> ~ <41> 10. The cleaning method according to claim 9, wherein the cleaning agent is a fluorine-containing compound.

[0116] <43> The material of the tableware is one or more selected from plastic (including silicone resin), metal, ceramic, wood, and combinations thereof. <38> ~ <42> 10. The cleaning method according to claim 9, wherein the cleaning agent is a fluorine-containing compound.

[0117] <44> The tableware is tableware having a hydrophobic surface. <38> ~ <43> 10. The cleaning method according to claim 9, wherein the cleaning agent is a fluorine-containing compound. [Example]

[0118] <Example 1 and Comparative Example 1> Tableware was washed in an automatic dishwasher (S45VS6SD, manufactured by Panasonic) using the liquid dishwasher detergent compositions shown in Table 1, and the detergency for oily stains and the finish (I) were evaluated by the following methods. The results are shown in Table 1.

[0119] (1) Ability to clean oil stains Four polypropylene dishes were placed in an automatic dishwasher. Two of the dishes were contaminated with a 1:1 (by mass) mixture of lard and rapeseed (3 g per dish), and the remaining two were uncontaminated. 6 g of the liquid dishwasher detergent composition shown in Table 1 was added, and the dishwasher was washed on the standard cycle. A total of three panelists touched the washed dishes and gave them scores based on the following criteria. The average scores were rounded to the nearest whole number and are shown in the table. The concentration of component (a) in the cleaning liquid applied to the tableware (cleaning liquid formed by diluting the liquid detergent composition with water) was 10 ppm when the amount of the composition added was 6 g. *Evaluation standard for cleaning oily stains 4: The dirt has been removed and it feels nice and squeaky to the touch. 3: The dirt has been removed, but there is no squeaky feeling when you touch it. 2: Most of the dirt appears to have been removed, but rubbing with your fingers leaves streaks. 1: You can see that there is oil remaining.

[0120] (2) Finishability (I) A clean black polypropylene lunch box was placed in an automatic dishwasher. Six grams of the liquid dishwasher detergent composition shown in Table 1 was added, and the dishwasher was washed using the standard cycle. A total of three panelists compared the washed lunch boxes with unwashed lunch boxes and evaluated them according to the following criteria. The average scores, rounded to one decimal place, are shown in Table 1. The concentration of component (a) in the cleaning liquid applied to the tableware (cleaning liquid formed by diluting the liquid detergent composition with water) was 10 ppm when the amount of the composition added was 6 g. 3: Clean with almost no white water spots or cloudiness remaining. 2: White water spots and cloudiness have appeared on about half of the lunch box. 1: White water spots and cloudiness remain on more than half of the lunch box, and the occurrence is clearly greater than level 2.

[0121] [Table 1]

[0122] *1 pH was adjusted with monoethanolamine. *2 The viscosity was measured at 25°C using a Brookfield viscometer with a rotor speed of 6 rpm, one minute after the start of rotation.

[0123] The ingredients in Table 1 are as follows. Note that although ingredient (a') in Table 1 is also ingredient (c), it is used as a component to be compared with ingredient (a), and is therefore conveniently shown as ingredient (a'). The "+" next to the enzymes indicates that amylase (Duramyl 120T (Novozymes)) was blended as an enzyme protein in the composition at 0.001% by mass, and protease (Savinase 18T-B (Novozymes)) was blended as an enzyme protein in the composition at 0.001% by mass (the same applies hereinafter). Xanthan gum: DSP Keldent manufactured by Gokyo Food & Chemical Co., Ltd., viscosity standard 1200-1700 mPa·s (measurement method for viscosity standard is as follows) (Viscosity standard measurement method) The viscosity of an aqueous solution containing 1% by mass of xanthan gum (Keldent) and 1% by mass of KCl is measured at 25°C using a Brookfield viscometer with a No. 3 rotor at 60 rpm, and the measured value is multiplied by 20 to obtain the viscosity standard (mPa·s). This viscosity standard value is approximately the same as the viscosity value of a 1% by mass aqueous solution measured using the method described above.

[0124] Hydrogenated castor oil mixture: Mixture 2 (a mixture of 2.9% hydrogenated castor oil, 11.7% sodium alkylbenzenesulfonate (component (c1)), and 85.4% water) obtained through steps 1 and 2 in <Example 1> <Preparation of Mixture 2> of JP 2016-147935 A, without carrying out <Optional Step A>; (a) / (b) in the table is calculated based on the amount of hydrogenated castor oil. Polyacrylic acid: Sumitomo Seika Chemicals Co., Ltd. Akupec HV-701EDR (viscosity of 1% by weight aqueous solution (25°C) 10,000 mPa·s or more) Polypropylene glycol: Number average molecular weight 3000

[0125] <Example 2> Using the liquid dishwasher detergent compositions shown in Table 2, dishes were washed in an automatic dishwasher (S45VS6SD, manufactured by Panasonic Corporation), and the cleaning ability for oily stains was evaluated in the same manner as in Example 1. The finish (II) was also evaluated in the following manner. The results are shown in Table 2. (1) Finishing quality (II) (1-1) Method for producing protein stains After making a soft-boiled egg (with the yolk part half-cooked and solidified) in a frying pan, the egg liquid was collected using a strainer. (1-2) Evaluation method Two clean glass cups were placed in an automatic dishwasher, and 2.5 g of the egg liquid collected in (1-1), 2.5 g of grease stains from lard and rapeseed (1:1 mass ratio), and 6 g of the dishwasher detergent composition listed in the table were added, and the dishwasher was run on the standard cycle. After washing, three panelists held the glass cups up to a light source (fluorescent lamp, AP Japan Co., Ltd., model number: 100V-4NSP, 10 cm from the light source) and visually observed them, assigning a score to each of the two cups according to the following criteria. The average of all the panelists' scores was used as the evaluation result. The average scores, rounded to one decimal place, are shown in Table 2. The concentration of component (a) in the cleaning liquid applied to the dishes (cleaning liquid formed by diluting the dishwasher detergent composition with water) was 10 ppm when the amount of the composition added was 6 g. 4: Clean with almost no water spots or cloudiness 3: Water spots and / or cloudiness have occurred in less than a quarter of the entire cup, but this does not affect use and does not require re-washing. 2: Water spots and / or cloudiness are present in more than a quarter of the cup but less than half, requiring re-washing. 1: Water spots and / or cloudiness have occurred in more than half of the cup, to the point that re-washing is necessary.

[0126] [Table 2]

[0127] *1 pH was adjusted with monoethanolamine.

[0128] The ingredients in Table 2 are as follows: Xanthan gum: same as in Table 1 Nonionic surfactant (1): Polyoxyethylene alkyl ether, in which an average of 3 moles of oxyethylene groups are added to a secondary higher alcohol with an alkyl group of 12 carbon atoms. Polypropylene glycol: same as in Table 1

[0129] <Combination example> Table 3 shows examples of liquid detergent compositions for dishwashers according to the present invention.

[0130] [Table 3]

[0131] *1 pH was adjusted with monoethanolamine.

[0132] The ingredients in the table are as follows: Xanthan gum: same as in Table 1 Guar gum: Fujifilm Wako Pure Chemical Industries, Ltd. (viscosity of 1% by weight aqueous solution (25°C) 3000-5000 mPa.s) Hydroxyethyl cellulose: Daicel Corporation HEC Daicel EE820 Polyvinyl alcohol: Kuraray Poval 22-88 manufactured by Kuraray Co., Ltd. Nonionic surfactants (1): the same as in Table 2 Polyacrylic acid / maleic acid copolymer: weight-average molecular weight 21,000, acrylic acid / maleic acid = 71 / 29 (molar ratio) (viscosity of 1% by weight aqueous solution (25°C) is 50 mPa·s or less) Polypropylene glycol: same as in Table 1 Silicone compound: Shin-Etsu Chemical Co., Ltd. emulsion type silicone KM-72

Claims

1. A liquid detergent composition for a dishwashing machine, containing (a) a branched alkyl sulfosuccinate ester in which the branched alkyl group has 9 to 11 carbon atoms [hereinafter referred to as component (a)], (b) a thickener [however, excluding thickeners composed of polymers containing acrylic acid as a monomer unit] [hereinafter referred to as component (b)], and water.

2. The liquid detergent composition for a dishwashing machine according to Claim 1, wherein the content of the polymer containing acrylic acid as a monomer unit is 5% by mass or less in the composition.

3. The liquid detergent composition for a dishwashing machine according to Claim 1, wherein component (b) is a thickener selected from a water-soluble polymer thickener and hydrogenated castor oil.

4. The liquid detergent composition for a dishwashing machine according to Claim 1, wherein the branched alkyl group of component (a) is a branched alkyl group having a main chain of 6 or 7 carbon atoms and one or more side chains, and the total number of carbon atoms in the side chains is 3 or 4.

5. The liquid detergent composition for a dishwashing machine according to Claim 1, wherein the branched alkyl group of component (a) is a branched alkyl group selected from a 2-propylheptyl group and a 3,5,5-trimethylhexyl group.

6. Further containing an anionic surfactant selected from alkanesulfonic acids having 8 to 12 carbon atoms, alkyl sulfates having 8 to 12 carbon atoms, polyoxyalkylene alkyl ether sulfates having an alkyl group of 8 to 12 carbon atoms, and salts thereof, the liquid detergent composition for a dishwashing machine according to Claim 1.

7. A method for washing tableware in a dishwashing machine, using a washing liquid containing the liquid detergent composition for a dishwashing machine according to any one of Claims 1 to 6 and water.

8. The washing method according to Claim 7, wherein the concentration of component (a) in the washing liquid is 1 ppm or more and 1000 ppm or less.

9. The cleaning method according to claim 7, wherein the temperature of the cleaning liquid is 40°C or higher.