Powder detergent composition

Abstract

To provide a powder detergent composition suitable for clothing which has excellent cleaning power and excellent solubility in water and rinsability.SOLUTION: There is provided a powder detergent composition using detergent particles comprising a surfactant (A), at least one component (B) selected from the group consisting of an alkali metal salt of a carbonate and an alkali metal salt of a sulfate and a metal soap (C), wherein the surfactant (A) includes at least one nonionic surfactant, the metal soap (C) is uniformly dispersed in the detergent particles and the content of the metal soap (C) is 0.8 pt.mass or more and less than 15.0 pts.mass based on 100 pts.mass of the whole powder detergent composition.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a powder detergent composition (hereinafter also simply referred to as "detergent composition"), and more particularly to a powder detergent composition that has excellent detergency, solubility in water, and rinsability, and is suitable for use on clothing. [Background technology]

[0002] Powder detergents containing a surfactant as a main component and an alkali agent, a polyvalent metal ion-trapping builder, or other auxiliary components are known. To wash clothes using such powder detergents, the powder detergent must be dissolved in water. Therefore, powder detergents are required to have excellent solubility in water in addition to their detergency.

[0003] As a technology aimed at improving the solubility of powder detergents in water, for example, Patent Document 1 proposes coated particles that can maintain good manufacturability and powder properties while suppressing aggregation with nearby detergent particles due to, for example, surfactant gelation, a detergent composition using these coated particles, and a method for producing the same.The powdery coated particles are obtained by coating the surface of core particles containing a surfactant and / or a detergent builder with one or more salts in powder form selected from the group consisting of organic acid salts and inorganic acid salts that have a solubility in water of 1 g or more / 100 g at 5°C and contain potassium ions, magnesium ions, or calcium ions as the cation. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-336094 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, environmental concerns have led to a desire to conserve water when washing clothes. However, in the case of powder detergents, if the amount of water used for washing is reduced, the powder detergent added may not dissolve completely, resulting in the problem of the remaining powder detergent adhering to the clothes. In addition, to conserve water, it is also necessary to reduce the number of rinses and the amount of water used for rinsing.

[0006] Therefore, an object of the present invention is to provide a new powder detergent composition that has excellent detergency, excellent solubility in water, and excellent rinsability, and is suitable for use on clothing. [Means for solving the problem]

[0007] The present inventors discovered that the insoluble nature of powder detergent compositions is due to the solidification of sodium sulfate or sodium carbonate, which are used as alkaline agents or process additives, in water. Therefore, the present inventors investigated the use of organic acids, which are known solubilizers, but this resulted in a new problem: the solubility of the powder detergent composition in cold water deteriorates again when the composition is stored for a long period of time. After further intensive research, including addressing this problem, the present inventors discovered that by uniformly dispersing a predetermined amount of metal soap in detergent particles containing a surfactant and sodium sulfate and / or sodium carbonate, the solidification of sodium sulfate or sodium carbonate in cold water can be prevented for a long period of time, thereby completing the present invention.

[0008] That is, the powder detergent composition of the present invention is a powder detergent composition using detergent particles containing a surfactant (A), at least one member (B) selected from the group consisting of an alkali metal carbonate and an alkali metal sulfate, and a metal soap (C), wherein: The surfactant (A) contains at least one nonionic surfactant, The metal soap (C) is uniformly dispersed in the detergent particles, and the content of the metal soap (C) is 0.8 parts by mass or more and less than 15.0 parts by mass, based on 100 parts by mass of the total powder detergent composition.

[0009] The powder detergent composition of the present invention preferably further contains an oil absorbing agent. Furthermore, in the powder detergent composition of the present invention, the aliphatic carboxylic acid constituting the metal soap (C) is preferably an aliphatic carboxylic acid having 10 to 22 carbon atoms. Furthermore, in the powder detergent composition of the present invention, the surfactant (A) preferably contains 70 mass % or more of the nonionic surfactant. The powder detergent composition of the present invention can be suitably used for clothing. [Effects of the Invention]

[0010] According to the present invention, a new powder detergent composition having excellent detergency, solubility in water, and rinsability can be provided. The powder detergent composition of the present invention has the advantages of being excellent in solubility in cold water and maintaining its effectiveness even after long-term storage, and is particularly suitable for use as a powder detergent for clothing. DETAILED DESCRIPTION OF THE INVENTION

[0011] The powder detergent composition of the present invention will be described in detail below. The detergent composition of the present invention is a powdery detergent composition using detergent particles containing surfactant (A), at least one surfactant (B) selected from the group consisting of alkali metal carbonates and alkali metal sulfates, and metal soap (C) (hereinafter referred to as "component (A)," "component (B)," and "component (C)"). In the detergent composition of the present invention, surfactant (A) contains at least one nonionic surfactant, and a predetermined amount of component (C) is uniformly dispersed in the detergent particles. By uniformly dispersing the predetermined amount of component (C) in the detergent particles in this manner, coagulation of the alkali metal carbonates and alkali metal sulfates can be prevented, and as a result, the detergent composition can be prevented from remaining undissolved in water. The components of the detergent composition of the present invention are described in detail below.

[0012] <Surfactant (A)> In the cleaning composition of the present invention, component (A) is a surfactant and contains at least one nonionic surfactant. For example, by dissolving this nonionic surfactant by applying heat or in a solvent, components (B), (C), and any powder components aggregate to form cleaning agent particles. Therefore, the nonionic surfactant is preferably a solid at 20°C that is liquefied by heating. In the cleaning composition of the present invention, component (A) may consist solely of a nonionic surfactant, or may be used in combination with various surfactants conventionally used in cleaning agents, such as anionic surfactants, cationic surfactants, and amphoteric surfactants.

[0013] Examples of nonionic surfactants include polyoxyalkylene alkyl ethers, ester-type polyoxyalkylene alkyl ethers, polyoxyalkylene dialkyl ethers, polyoxyalkylene alkylphenyl ethers, fatty acid alkanolamides, polyoxyalkylene fatty acid alkanolamides, polyoxyalkylene fatty acid esters, polyoxyalkylene sorbitan fatty acid esters, alkyl glyceryl ethers, polyglycerin fatty acid esters, sorbitan fatty acid esters, sorbitol fatty acid esters, methyl glucoside fatty acid esters, methyl mannoside fatty acid esters, ethyl glucoside fatty acid esters, sucrose fatty acid esters, alkyl glucosides, alkyl polyglycosides, alkanoyl-N-methylglucamides, polyoxyethylene methyl ether fatty acid esters, fatty acid methyl ester ethoxylates, and polyoxyalkylene alkylamines.

[0014] In the detergent composition of the present invention, polyoxyalkylene alkyl ethers can be suitably used as the nonionic surfactant, and those having an alkyl group with 6 or more, preferably 8 or more, and 22 or less, preferably 18 or less, carbon atoms can be suitably used. Among polyoxyalkylene alkyl ethers, polyoxyethylene alkyl ethers are preferred, and the average number of moles of polyoxyethylene alkyl ether oxyethylene groups added is preferably 3 to 50, more preferably 9 to 16.

[0015] Examples of commercially available nonionic surfactants include the Emulmin series manufactured by Sanyo Chemical Industry Co., Ltd., the Adekatall series manufactured by ADEKA Corporation, the Brownon series manufactured by Aoki Oil & Fat Co., Ltd., and the Leox series manufactured by Lion Corporation.

[0016] Examples of anionic surfactants include fatty acid soaps, linear alkylbenzene sulfonates, alkanesulfonates, α-olefin sulfonates, linear or branched alkyl sulfates, alkenyl sulfates, alkyl ether sulfates, alkenyl ether sulfates, polyoxyethylene alkyl ether sulfates, polyoxyethylene alkenyl ether sulfates, α-sulfofatty acid alkyl esters, sulfosuccinates, acylated isethionates, acylated peptide salts, acylated amino acid salts, and phosphate salts.

[0017] In the cleaning composition of the present invention, an alkyl sulfate can be suitably used as the anionic surfactant. The alkyl sulfate preferably has an alkyl group having 8 or more, preferably 10 or more, and 20 or less, preferably 18 or less, more preferably 14 or less, and even more preferably 12 or less carbon atoms. The alkyl group may have a linear or branched chain.

[0018] As the alkylbenzenesulfonate, a linear alkylbenzenesulfonate having a linear alkyl group with 8 to 16 carbon atoms is preferred, and a linear alkylbenzenesulfonate having a linear alkyl group with 12 to 14 carbon atoms is particularly preferred.

[0019] Examples of the α-sulfofatty acid alkyl ester salt include α-sulfofatty acid alkyl ester salts represented by the following general formula (I). R 1 -CH(SO3M)-COOR 2 (I) Here, in general formula (I), R 1 is a hydrocarbon group having 14 to 16 carbon atoms, and R2 is a hydrocarbon group having 1 to 6 carbon atoms, and M is a counter ion.

[0020] In general formula (I), R 1 The hydrocarbon group may be linear or branched, or may contain a cyclic structure. 1 The hydrocarbon group is preferably an aliphatic hydrocarbon group, more preferably a linear or branched alkyl group or a linear or branched alkenyl group, and even more preferably a linear alkyl group or a linear alkenyl group.

[0021] R 2 The hydrocarbon group may be linear or branched, or may contain a cyclic structure. 2 The hydrocarbon group in R is preferably an aliphatic hydrocarbon group, more preferably a linear or branched alkyl group or a linear or branched alkenyl group, and even more preferably a linear alkyl group or a branched alkyl group. 2 The number of carbon atoms in R is 1 to 6, preferably 1 to 3. 2 Examples of the hydrocarbon group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, etc. Methyl, ethyl, and n-propyl groups are preferred, with a methyl group being particularly preferred, as they further improve the detergency of the cleaning component.

[0022] M is a counterion and R 1 CH(COOR 2 )SO3 - Any counter ion M may be used as long as it can form a water-soluble salt with M. Examples of the counter ion M include alkali metal ions, protonated amines, and ammonium. As the counter ion M, alkali metal ions are preferred, and sodium ions are particularly preferred, because they are easily available and tend to further improve the low-temperature stability of the liquid detergent.

[0023] Commercially available anionic surfactants include, for example, alkyl sulfate salts such as Texapon (registered trademark) OC-N (manufactured by BASF), EMAL 0S (manufactured by Kao Corporation), EMAL 10PT (manufactured by Kao Corporation), EMAL TD (manufactured by Kao Corporation), and EMAL AD-25R (manufactured by Kao Corporation); polyoxyethylene alkyl ether sulfate salts such as Teikapol NE1230 (manufactured by Teika Corporation), Teikapol NE1270 (manufactured by Teika Corporation), Teikapol NE1325 (manufactured by Teika Corporation), and Teikapol NE1370 (manufactured by Teika Corporation); linear alkylbenzene sulfonate salts such as "Teika Power LN2425" (manufactured by Teika Corporation) and "Lipon LS-250" (manufactured by Lion Specialty Chemicals Co., Ltd.); and α-sulfofatty acid alkyl ester salts such as "MIZULAN FL-80" (LION ECO CHEMICALS SDN.BHD.), and PALMFONATE 6909F (KL-KEPONG OLEOMAS SDN.BHD.).

[0024] Examples of cationic surfactants include didecyl dimethyl ammonium chloride, didecyl dimethyl ammonium methosulfate, distearyl dimethyl ammonium chloride, dioctyl dimethyl ammonium chloride, distearyl dihydroxyethyl ammonium chloride, di-beef tallow alkyl dimethyl ammonium chloride, di(stearoyloxyethyl) dimethyl ammonium chloride, di(oleoyloxyethyl) dimethyl ammonium chloride, di(palmitoyloxyethyl) dimethyl ammonium methosulfate, di(stearoyloxyisopropyl) dimethyl ammonium chloride, di(oleoyloxyisopropyl) dimethyl ammonium chloride, di(oleoyloxybutyl) dimethyl ammonium chloride, di(stearoyloxyethyl) methyl hydroxyethyl ammonium methosulfate, tri(stearoyloxyethyl) methyl methosulfate, lauryl trimethyl ammonium chloride, stearyl trimethyl ammonium chloride, etc. One type of cationic surfactant may be used alone, or two or more types may be used in appropriate combination.

[0025] Examples of amphoteric surfactants include alkyl dimethylamine oxides such as lauryl dimethylamine oxide, coconut alkyl dimethylamine oxide, and lauryl diethylamine oxide; and alkanoyl amido alkyl dimethylamine oxides such as lauric acid amidopropyl amine oxide.

[0026] Further examples include aminoacetic acid betaines such as lauryl dimethylaminoacetic acid betaine, coconut alkyl dimethylaminoacetic acid betaine, and lauric acid amidopropyl dimethylaminoacetic acid betaine; sulfobetaines such as N-lauryl-N,N-dimethylammonium-N-propyl sulfobetaine and N-lauryl-N,N-dimethylammonium-N-(2-hydroxypropyl) sulfobetaine; glycine-based compounds such as 2-lauryl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine and sodium lauryl diaminoethyl glycine; and aminopropionic acid-based compounds such as sodium lauryl aminopropionate and sodium lauryl aminodipropionate.

[0027] In the detergent composition of the present invention, the nonionic surfactant (A) may be used singly or in combination of two or more. As described above, the component (A) may also be used in combination with a surfactant other than the nonionic surfactant, for example, a nonionic surfactant and an anionic surfactant may be used in combination. From the viewpoints of detergency, rinsing ability, and fluidity, the nonionic surfactant is preferably present in the surfactant (A) in an amount of 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more.

[0028] In the cleaning composition of the present invention, the content of component (A) is not particularly limited, but is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and even more preferably 5 parts by mass or more, relative to 100 parts by mass of the entire cleaning composition. The content of component (A) is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, and even more preferably 12 parts by mass or less. If component (A) is less than 1 part by mass relative to 100 parts by mass of the entire cleaning composition, sufficient detergency may not be obtained, whereas if it exceeds 20 parts by mass, the cleaning composition may become sticky.

[0029] <(B) At least one selected from the group consisting of alkali metal carbonates and alkali metal sulfates> The alkali metal carbonates and alkali metal sulfates of component (B) are components mainly used as alkaline agents or process additives. These components tend to coagulate in water, causing them to remain undissolved. However, the detergent composition of the present invention solves this problem by adding component (C), which will be described later. In the detergent composition of the present invention, examples of alkali metal carbonates include sodium carbonate and potassium carbonate, with sodium carbonate being preferred. Examples of alkali metal sulfates include sodium sulfate and potassium sulfate, with sodium sulfate being preferred.

[0030] In the cleaning composition of the present invention, these components may be used alone as component (B), or two or more types may be used in combination. The content of component (B) in the cleaning composition of the present invention is not particularly limited, but is preferably at least 30 parts by mass, more preferably at least 40 parts by mass, and even more preferably at least 50 parts by mass, relative to 100 parts by mass of the total cleaning composition. It is also preferably at most 90 parts by mass, more preferably at most 80 parts by mass, and even more preferably at most 70 parts by mass. If the content of component (B) is less than 30 parts by mass relative to 100 parts by mass of the total cleaning composition, it may not function sufficiently as an alkaline agent or process additive, resulting in insufficient detergency or impaired fluidity. If the content exceeds 90 parts by mass, component (B) may aggregate significantly in cold water, potentially resulting in residual undissolved components in the cleaning composition.

[0031] <Metal soap (C)> In the detergent composition of the present invention, component (C) is a metal soap, preferably a salt of an aliphatic carboxylic acid and at least one selected from the group consisting of calcium, aluminum, zinc, and magnesium. This metal soap (C) is uniformly dispersed in detergent particles primarily composed of components (A) and (B). The use of component (C) prevents the coagulation of alkali metal carbonates and alkali metal sulfates in water, improving the solubility of the detergent composition in water. As a result, the detergent composition is prevented from remaining undissolved during washing. Component (C) also has a defoaming effect, reducing foaming during washing. This also improves the rinsing properties of the detergent composition.

[0032] In the detergent composition of the present invention, there are no particular restrictions on the aliphatic carboxylic acid that constitutes component (C), but the number of carbon atoms in the aliphatic carboxylic acid is preferably 10 or more, more preferably 12 or more, and even more preferably 14 or more. The number of carbon atoms in the aliphatic carboxylic acid is also preferably 24 or less, more preferably 22 or less, and even more preferably 20 or less. Calcium stearate is particularly preferred.

[0033] In the cleaning composition of the present invention, the content of component (C) is 0.8 parts by mass or more and less than 15.0 parts by mass, based on 100 parts by mass of the entire cleaning composition. If the content is less than 0.8 parts by mass, cold water coagulation of component (B) cannot be sufficiently suppressed, and improvement in the solubility in water of the cleaning composition or improvement in rinsing performance cannot be expected. On the other hand, if the content exceeds 15.0 parts by mass, component (C) cannot be sufficiently dispersed in water, which may cause it to remain undissolved. Preferably, the content is 1.0 parts by mass or more and 10.0 parts by mass or less.

[0034] <Other optional ingredients> The cleaning composition of the present invention preferably contains an oil-absorbing agent, and silicon dioxide is preferably used as the oil-absorbing agent. By using silicon dioxide, the cleaning particle of the present invention contains components (A), (B), and (C), as well as silicon dioxide. As a result, the flowability of the cleaning composition of the present invention is improved, and further, the solubility of the cleaning composition in water is improved. The content of silicon dioxide is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, and is preferably 5.0 parts by mass or less, more preferably 2.0 parts by mass or less, based on 100 parts by mass of the total cleaning composition. When the content of silicon dioxide is 0.1 parts by mass or less, based on 100 parts by mass of the total cleaning composition, the oil-absorbing capacity may be insufficient, which may lead to exudation of the surfactant and deterioration of the flowability. On the other hand, when the content of silicon dioxide is more than 5.0 parts by mass, the amount of fine powder in the cleaning composition may increase, which may also result in deterioration of the flowability. In the detergent composition of the present invention, in addition to silicon dioxide, amorphous calcium silicate, amorphous silica, etc. may also be used as the oil absorbent.

[0035] Examples of commercially available silicon dioxide products include the Nipsil series manufactured by Tosoh Silica Corporation.

[0036] Furthermore, the detergent composition of the present invention may contain, as necessary, other additives such as an alkaline agent other than component (B), a water softener, a bleaching agent, a processing agent other than component (B), a dissolution promoter, a sequestering agent, an anti-redeposition agent, a polycarboxylate, an enzyme, a chlorine scavenger, a hydrotrope, an enzyme activator, an antioxidant, a preservative, a colorant, a fragrance, and a pH adjuster, provided that the effects of the present invention are not impaired.

[0037] Examples of alkali agents other than component (B) include sodium bicarbonate, crystalline layered sodium silicate, and sodium silicate.

[0038] Examples of water softeners include crystalline aluminosilicates such as zeolites, and aluminosilicates such as amorphous aluminosilicates.

[0039] Examples of bleaching agents include hydrogen peroxide, sodium persulfate, sodium percarbonate, and sodium perborate.

[0040] Examples of processing agents other than component (B) include calcium carbonate.

[0041] Examples of the dissolution promoter include inorganic ammonium salts such as ammonium chloride; benzenesulfonates having a short-chain alkyl group having 1 to 5 carbon atoms such as sodium p-toluenesulfonate, sodium xylenesulfonate, and sodium cumenesulfonate; sodium benzoate, sodium benzenesulfonate, sodium chloride, citric acid, tartaric acid, D-glucose, urea, and sucrose.

[0042] Examples of sequestering agents include citric acid, lactic acid, tartaric acid, oxalic acid, malic acid, gluconic acid, nitrilotriacetic acid, iminodiacetic acid, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, glycoletherdiaminetetraacetic acid, and hydroxyethyliminodiacetic acid.Furthermore, organic phosphonic acid derivatives such as triethylenetetraaminehexaacetic acid, ethane-1,1-diphosphonic acid, ethane-1,1,2-triphosphonic acid, 1-hydroxyethane-1,1-diphosphonic acid, ethanehydroxy-1,1,2-triphosphonic acid, ethane-1,2-dicarboxy-1,2-diphosphonic acid, methanehydroxyphosphonic acid, aminotrimethylenephosphonic acid, and ethylenediaminetetraxymethylenesulfonic acid, as well as salts thereof.

[0043] Examples of anti-redeposition agents include polyethylene glycol, polyvinyl alcohol, polyvinylpyrrolidone, and carboxymethyl cellulose.

[0044] Examples of polycarboxylates include polyacrylic acid (salts), acrylic acid-allyl alcohol copolymers (salts), acrylic acid-maleic acid copolymers (salts), acrylic acid-sulfonic acid monomer copolymers (salts), polyhydroxyacrylic acid (salts), polycarboxylic acid ethers, and polytetramethylene-1,2-dicarboxylic acid (salts).

[0045] Examples of the enzyme include cellulase, protease, amylase, lipase, mannanase, and the like.

[0046] Examples of chlorine scavengers include ammonium sulfate, guanidine hydrochloride, guanidine carbonate, guanidine sulfamate, thiourea dioxide, monoethanolamine, diethanolamine, and triethanolamine.

[0047] Examples of hydrotropic agents include water-soluble solvents such as ethanol, propylene glycol, and polyethylene glycol; aromatic sulfonic acids such as toluenesulfonic acid, xylenesulfonic acid, cumenesulfonic acid, and substituted or unsubstituted naphthalenesulfonic acid, or salts thereof; and aromatic carboxylic acids such as benzoic acid and sodium benzoate, or salts thereof.

[0048] Examples of antioxidants include tert-butylhydroxytoluene (hereinafter, tert-butyl will be abbreviated as t-butyl), 4,4′-butylidenebis-(6-t-butyl-3-methylphenol), 2,2′-butylidenebis-(6-t-butyl-3-methylphenol), monostyrenated cresol, distyrenated cresol, monostyrenated phenol, distyrenated phenol, and 1,1′-bis-(4-hydroxyphenyl)cyclohexane.

[0049] The detergent composition of the present invention has excellent solubility in water and excellent rinsing properties, and therefore can be suitably used as a powder detergent composition for clothing, but its applications are not limited thereto. The detergent composition of the present invention can also be used, for example, as a dishwashing detergent composition for hand washing or for automatic dishwashers, and can also be used as a powder detergent composition for household and automotive detergents, for personal use, and for metals.

[0050] The detergent composition of the present invention comprises detergent particles containing the components (A) and (B), and the component (C) uniformly dispersed in the detergent particles. The method for producing the detergent composition of the present invention is not particularly limited as long as the component (C) can be uniformly dispersed in the detergent particles, and the detergent composition can be produced by any conventional method for producing powdery detergent compositions.

[0051] The method for producing the detergent composition of the present invention includes, for example, a spray drying method in which a slurry containing components (A) to (C) and other optional components is prepared, and the slurry is sprayed and dried. However, the method for producing the detergent composition of the present invention is not limited to this. In addition to the spray drying method, the detergent composition of the present invention may also be produced by a dry neutralization method, a dry granulation method, a dry blend method, a fluidized bed drying method, a thin film drying method, an extrusion granulation method, a tumbling granulation method, an agitation granulation method, a compaction granulation method, or a surfactant supporting method. [Example]

[0052] The cleaning composition of the present invention will be described in more detail below using examples, but the present invention is not limited to these examples.

[0053] Each detergent composition was produced by spray drying according to the formulations shown in Tables 1 to 5. In each of the resulting detergent compositions, except for Comparative Example 1, the metal soap was uniformly dispersed in the detergent particles. These detergent compositions were evaluated for detergency, solubility (cold water coagulation, evaluated using an actual washing machine), rinsability, and fluidity. Detailed procedures for each evaluation item are as follows. In the tables, the units are parts by mass.

[0054] <Cleaning power evaluation> 1. The reflectance of 10 pieces of artificially soiled cloth (product name: Wet Artificially Soiled Cloth, Sorits Co., Ltd.) before washing was measured using a color difference meter (SA5500, Nippon Denshoku Industries Co., Ltd.). 2. A Tergot-o-Tometer (WT-0121 KOKOKU MACHINERY WORKS LTD.) was used as a cleaning tester, and 10 pieces of soiled cloth and a knitted cloth (cut to 50 x 50 mm) were placed in a cleaning tank at a bath ratio of 1:30. 3. A cleaning solution was poured into the washing tank. The cleaning solution was prepared by dissolving the powder detergent composition for clothing in 1000 mL of water adjusted to a German hardness of 2.8 DH (same applies hereinafter) at 20°C to a concentration of 2500 ppm (by mass). 4. After washing for 10 minutes at 120 rpm and 20°C, the cloth was dehydrated for 1 minute and then rinsed once with 1000 mL of hardness-adjusted water at 20°C for 3 minutes. After dehydration for 1 minute, the cloth was dried and washed, and the reflectance of the soiled cloth was measured, and the cleaning rate was calculated using the following formula. Cleaning rate (%) = (K / S of soiled cloth - K / S of cleaned cloth) / (K / S of soiled cloth - K / S of unsoiled cloth) x 100 Here, in formula (i), K / S is (1-R / 100) / (2R / 100), the soiled cloth refers to the artificially soiled cloth, the washed cloth refers to the soiled cloth after washing, and the unsoiled cloth refers to the original unsoiled white cloth (raw cloth), K refers to the absorption coefficient, S refers to the scattering coefficient, and R refers to the absolute reflectance.

[0055] Detergency evaluation criteria ◎: The average cleaning rate of 10 sheets is 65% or more (passed) ○: The average cleaning rate of 10 sheets is 55% or more but less than 60% (pass) △: The average cleaning rate of 10 sheets is 50% or more but less than 55% (failure) ×: The average cleaning rate of 10 sheets is less than 50% (failure)

[0056] <Cold water coagulation evaluation> The cold water coagulation evaluation is a test to evaluate whether a detergent dissolves in cold water under harsh conditions that simulate a situation where the detergent has been placed in a clothing pocket, etc. 1. Wrap 20g of sample in gauze. 2. Tap water adjusted to 5°C is placed in a small washing machine (National NA-32, manufactured by Matsushita Electric Industrial Co., Ltd.), and the sample wrapped in gauze is allowed to stand in the water. 3. After leaving it to stand for 15 minutes, stir for 5 minutes and collect any remaining residue. 4. Dry the remaining residue in a dryer at 105°C for 1 hour. 5. Calculate the dissolution rate (%) from the remaining amount and the initial sample amount.

[0057] Cold water coagulation evaluation criteria ◎: Dissolution rate is 95% or more (passed) ○: Dissolution rate is 85% or more but less than 95% (pass) △: Dissolution rate is 70% or more but less than 85% (failure) ×: Dissolution rate is less than 70% (failure)

[0058] <Evaluation of residual detergent in an actual washing machine> The evaluation of residual detergent using an actual washing machine involves washing black clothes, which are more likely to be visible if residual detergent remains, and evaluating whether residual detergent adheres to the clothes. 1. Place 1.7 kg of items to be washed in a two-tier washing machine (PS-65AS2, manufactured by Hitachi, Ltd.) and place 72 g of the sample on top of it. 2. Place 1.7 kg of the item to be washed on top of the sample and sandwich the sample between the items to be washed. 3. Add 43 liters of adjusted 5°C tap water and wash in the following order: wash for 10 minutes, spin for 1 minute, rinse for 3 minutes, and spin for 1 minute. 4. After washing is complete, visually check the items to see if any powder remains dissolved.

[0059] Evaluation criteria for residual dissolution in an actual washing machine ○: No undissolved residue (passed) △: Spots of undissolved residue are observed (failed) ×: Undissolved residue is clearly visible (failed)

[0060] <Evaluation of rinsing ability (foam suppression)> The powder detergent composition for clothing was dissolved to a concentration of 2500 ppm (by mass) in 1000 mL of hardness-adjusted water adjusted to a German hardness of 2.8 DH at 1.25° C. This cleaning solution was diluted 10 times with the hardness-adjusted water to obtain a model rinse water. 2. 20 mL of model rinse solution was placed in an Epton tube and shaken up and down 20 times at 1 stroke per second. 3. One minute after the end of shaking, the height of the foam (the height from the boundary between the foam and the rinse liquid to the top surface of the foam) was read.

[0061] Evaluation criteria for rinsing (foam suppression) ○: Bubble height less than 5 mm (pass) △: Bubble height is 5mm or more but less than 10mm (pass) ×: Bubble height is 10mm or more (failed)

[0062] <Liquidity evaluation> This is a test to evaluate the handleability of detergent granules. The flowability is defined as the time required for 100 mL of powder to flow out of a hopper for measuring apparent density as described in JIS k 3362:2008.

[0063] Liquidity Assessment Criteria ◎: Less than 6.5 seconds (pass) ○: Less than 6.5 to 8.0 seconds (pass) △: 8.0 seconds or more (fail) ×: Bridging occurs in the hopper and no flow occurs (failed)

[0064] <Stability evaluation> This is a test to evaluate the long-term stability of the cold water coagulation effect. Each powder detergent composition for clothing was stored in a thermostatic chamber at 50°C and a relative humidity of 50% for 3 months, and then the cold water coagulation property was evaluated using the procedure described above.

[0065] Stability Evaluation Criteria ◎: Dissolution rate is 95% or more (passed) ○: Dissolution rate is 85% or more but less than 95% (pass) △: Dissolution rate is 70% or more but less than 85% (failure) ×: Dissolution rate is less than 70% (failure)

[0066] [Table 1] *1: Emulmin LS-90 (manufactured by Sanyo Chemical Industries, Ltd.) *2: Texapon OC-N (manufactured by BASF) *3: Nipsil NS (Tosoh Silica Corporation) *4: Protease, amylase, lipase, mannanase

[0067] [Table 2]

[0068] [Table 3]

[0069] [Table 4]

[0070] [Table 5]

[0071] When metal soap is blended in an amount of 0.8% or more, cold water solubility and rinsability can be improved. However, it was found that when the blending rate is 15% or more, the metal soap does not disperse in water, resulting in residual residue. It was also found that the powder detergent composition of the present invention can maintain its solubility for a long period of time.

Claims

1. A powder detergent composition using detergent particles containing a surfactant (A), at least one member (B) selected from the group consisting of an alkali metal carbonate and an alkali metal sulfate, and a metal soap (C), The surfactant (A) contains at least one nonionic surfactant, The powder detergent composition is characterized in that the metal soap (C) is uniformly dispersed in the detergent particles, and the content of the metal soap (C) is 0.8 parts by mass or more and less than 15.0 parts by mass, based on 100 parts by mass of the total powder detergent composition.

2. 2. The powder detergent composition according to claim 1, further comprising an oil absorbing agent.

3. 2. The powder detergent composition according to claim 1, wherein the aliphatic carboxylic acid constituting the metal soap (C) is an aliphatic carboxylic acid having 10 to 22 carbon atoms.

4. 2. The powder detergent composition according to claim 1, wherein the surfactant (A) contains the nonionic surfactant in an amount of 50% by mass or more.

5. The powder detergent composition according to any one of claims 1 to 4, which is for use on clothing.

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