JP2007284674A - Surfactant composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surfactant composition suppressing salt formation with calcium ions and magnesium ions included in water, even though water having high degree of hardness is used, and having excellent detergent effect, and provide a detergent composition including the same. <P>SOLUTION: The liquid surfactant composition comprises (a) one or more species selected from a group consisting of alkylbenzene sulfonic acids, alkylbenzene sulfonates, alkylsulfuric acids and alkylsulfuric acid salts and (b) a hydrocarbon group-containing polyoxyalkylene-based compound which has 10-30C hydrocarbon groups and contains polyoxyalkylene groups having sum total mass of ≤3C oxyalkylene groups and hydroxyl groups in 75-95% based on 100% whole mass of the compound. In the composition, the ratio of mass content of (a) and (b) satisfies the equation: (a):(b)=100:0.1-100:17. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a surfactant composition containing an anionic surfactant such as an alkylbenzene sulfonate and a specific hydrocarbon group-containing polyoxyalkylene compound. In particular, the present invention relates to a surfactant composition having an excellent cleaning effect even when water having high hardness is used, and a detergent composition containing the same.

Linear alkylbenzene sulfonates (LAS) and alkyl sulfates (AS) such as dodecylbenzenesulfonic acid are widely used as anionic surfactants used in detergents used in clothing due to their excellent cleaning effect. . Alkyl benzene sulfonate and alkyl sulfate are known to be sensitive to hardness components such as calcium ions and magnesium ions. That is, alkylbenzene sulfonate or alkyl sulfate and calcium or magnesium present in water form calcium salt or magnesium salt. And these salts precipitate and precipitate in washing water, As a result, the fall of a detergent density | concentration and the fall of a cleaning power are caused. For this reason, builders such as condensed phosphates, zeolites, silicates, or carbonates that generally capture metal ions are used in detergents to suppress calcium salt precipitation. However, if these builders are added sufficiently to satisfy the calcium scavenging ability, problems such as long-term storage stability of the detergent and adhesion of the builders to clothing may occur. As a means for solving this problem, in Non-Patent Document 1, even when the amount of builder added is small, the precipitation of the calcium salt can be reduced by adding a nonionic surfactant. It has been reported.
Louis Ho Tan Tai, “Formation of Detergents and Personal Care Products”, AOCS Press, 2000, p53-54.

  However, by combining any anionic surfactant and nonionic surfactant, the anionic surfactant does not form a salt even under high hardness conditions with high calcium and magnesium concentrations, and has an excellent cleaning effect No specific knowledge has been obtained about the current situation.

  Therefore, the present invention has been made in view of the above circumstances, and even when water having high hardness is used, formation of salts with calcium ions and magnesium ions contained in water is suppressed, and the present invention is excellent. It is an object of the present invention to provide a surfactant composition having a cleaning effect and a detergent composition containing the same.

  Another object of the present invention is to provide a washing method using such a surfactant composition or detergent composition and water having high hardness.

  As a result of intensive studies on various anionic surfactants and nonionic surfactants in order to achieve the above object, the present inventors have found that anionic surfactants such as alkylbenzene sulfonates and specific hydrocarbon group-containing polymers. The surfactant composition containing an oxyalkylene compound suppresses the precipitation of salts formed from an anionic surfactant and calcium ions or magnesium ions in water, and as a result can maintain an excellent cleaning effect. The headline and the present invention were completed.

  That is, the present invention has (a) one or more selected from the group consisting of alkylbenzene sulfonic acid, alkylbenzene sulfonate, alkyl sulfate and alkyl sulfate, and (b) a hydrocarbon group having 10 to 30 carbon atoms. A hydrocarbon group-containing polyoxyalkylene compound in which the total mass of the polyoxyalkylene group having 3 or less carbon atoms of the oxyalkylene group and the hydroxyl group is 75 to 95% with respect to 100% of the total mass of the compound, The surfactant composition in which the mass ratio of (a) to (b) is (a) :( b) = 100: 0.1 to 100: 17.

  Furthermore, the present invention has (a) one or more selected from the group consisting of alkylbenzene sulfonic acid, alkylbenzene sulfonate, alkyl sulfate and alkyl sulfate, and (b) a hydrocarbon group having 10 to 30 carbon atoms. And a hydrocarbon group-containing polyoxyalkylene compound having a HLB of 15.0 to 19.0, wherein the mass ratio of (a) and (b) is (a) :( b) = The surfactant composition is 100: 0.1 to 100: 17.

  Furthermore, this invention is a washing | cleaning method using the detergent composition containing the said surfactant composition, the said surfactant composition or the said detergent composition, and water with high hardness.

  By using the surfactant composition and the detergent composition of the present invention, even when washed with high-hardness water, precipitation of salts formed from an anionic surfactant and calcium ions or magnesium ions can be prevented. As a result, the high cleaning effect can be maintained.

  Hereinafter, the present invention will be described in detail.

  The surfactant composition according to the first embodiment contains (a) one or more selected from the group consisting of alkylbenzene sulfonic acid, alkylbenzene sulfonate, alkyl sulfate and alkyl sulfate as essential components.

  The alkylbenzenesulfonic acid / salt is not particularly limited as long as the effects of the present application can be obtained, and the alkyl group may be linear or branched. Preferably, the carbon number of the alkyl group is 8 to 20, more preferably 10 to 18, still more preferably 11 to 16, and particularly preferably 11 to 14. Further, alkylbenzenesulfonic acid / salt having a linear alkyl group is preferable. Furthermore, examples of the cation that forms a salt with alkylbenzenesulfonic acid include alkali metals such as sodium and potassium, and amines such as monoethanolamine, diethanolamine, and triethanolamine. Among these, sodium is preferably used.

  The alkyl sulfate / salt is not particularly limited as long as the effect of the present application can be obtained, and the alkyl group may be linear or branched. Preferably, the carbon number of the alkyl group is 8 to 20, more preferably 10 to 18, still more preferably 12 to 18, and particularly preferably 14 to 18. Also preferred is an alkyl sulfate / salt having a linear alkyl group. Examples of the cation that forms a salt with alkylsulfuric acid include alkali metals such as sodium and potassium, and amines such as monoethanolamine, diethanolamine, and triethanolamine. Among these, sodium is preferably used.

  The content of alkylbenzenesulfonic acid / salt and alkylsulfuric acid / salt in the surfactant composition is not particularly limited, but is preferable in order to effectively suppress the formation of salts with calcium and magnesium ions. Is 10 to 30% by mass (hereinafter simply referred to as%), more preferably 10 to 25%, based on the total amount of the composition.

  In order to obtain the effect of the present invention, the component (a) needs to be an anionic surfactant in the form of a salt by the final use form (for example, a detergent composition). Specifically, the surfactant composition may contain an alkylbenzene sulfonate or an alkyl sulfate which is in the form of a salt from the beginning, and the surfactant composition may be an alkylbenzene sulfonic acid or an alkyl sulfate. And a base, and finally it becomes an anionic surfactant in the surfactant composition, and a base is later added to the surfactant composition containing alkylbenzenesulfonic acid or alkylsulfuric acid. It can also be added to form an anionic surfactant.

  In addition to the component (a), it is a feature of the present invention that the component (b) includes a hydrocarbon group-containing polyoxyalkylene compound. By adding the component (b), even when washing is performed with water having high hardness, the formation of a salt of calcium ion or magnesium ion and an anionic surfactant is small, and a good cleaning effect is obtained. The hydrocarbon group-containing polyoxyalkylene compound refers to a compound containing at least a hydrocarbon group having 10 to 30 carbon atoms and a polyoxyalkylene group in the compound. The hydrocarbon group is not particularly limited, and may be linear, branched, saturated, or unsaturated.

  In one embodiment of the component (b) used in the present invention, the total mass of the polyoxyalkylene group having 3 or less carbon atoms in the oxyalkylene group and the hydroxyl group is 75 to 95% with respect to 100% of the total mass of the compound. It is a hydrocarbon group-containing polyoxyalkylene compound. From the viewpoint of suppressing the formation of a salt between the anionic surfactant and calcium in water, the total mass of the polyoxyalkylene group having 3 or less carbon atoms and the hydroxyl group is 87 to 94% with respect to 100% of the total mass of the compound. It is preferable. Here, as for the oxyalkylene group in a hydrocarbon group containing polyoxyalkylene type compound, only 1 type may exist independently and 2 or more types may exist. The oxyalkylene group in the polyoxyalkylene group is not only composed of oxyalkylene groups having 3 or less carbon atoms, but also oxyalkylene groups having 4 or more carbon atoms in the polyoxyalkylene group. It may be contained in the group.

  Another embodiment of the component (b) used in the present invention is such that the HLB is 15.0 to 19.5 from the viewpoint of suppressing the formation of a salt between an anionic surfactant and calcium in water or the like by calculation using the Griffin equation. 0, more preferably HLB is in the range of 17.5 to 18.8. The HLB is calculated by the method described in “Surfactant Physical Properties / Applications / Chemical Ecology” (Fumio Kitahara et al., P.24-25, Kodansha).

  The hydrocarbon group-containing polyoxyalkylene compound is not particularly limited as long as the effects of the present invention can be obtained, but from the viewpoint of inhibiting the formation of the salt, a compound represented by the following chemical formula (1) is preferred. It is.

  R in the chemical formula (1) represents a hydrocarbon group having 10 to 30 carbon atoms, and may be linear, branched, saturated, or unsaturated. Preferably, R has 10 to 20 carbon atoms, more preferably 10 to 18, more preferably 12 to 16, and particularly preferably 12 to 15. R is preferably an alkyl group or an alkenyl group. Examples of the alkyl group include decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, icosyl and the like. Examples of the alkenyl group include decylene group, undecylene group, dodecylene group, tridecylene group, tetradecylene group, pentadecylene group, hexadecylene group, heptadecylene group, octadecylene group, nonadecylene group, icosylene group, and the like. Among these, R is preferably a dodecyl group, a tridecyl group, a tetradecyl group, a dodecylene group, a tridecylene group, or a tetradecylene group, and more preferably a dodecyl group, a tridecyl group, or a tetradecyl group.

  X in the chemical formula (1) is

It is. Further, p in the chemical formula (1) represents an integer, preferably 0 or 1, more preferably 0.

  Y in the chemical formula (1) is

It is. From the viewpoint of suppressing calcium salt formation, more preferably, Y in the chemical formula (1) is —O—R ₁ . In the formula, R _{1 to} R ₄ each independently represents an alkylene group, preferably an alkylene group having 2 to 6 carbon atoms, more preferably 2 to 4 carbon atoms, still more preferably 2 to 3 carbon atoms, and particularly preferably 2 alkylene atoms. It is a group. R ₅ represents a hydrogen atom or a group represented by the following chemical formula (2);

It is. In the chemical formula (2), R ₆ and R ₇ each independently represent an alkylene group having 2 to 6 carbon atoms, preferably 2 to 6 carbon atoms, more preferably 2 to 4 carbon atoms, still more preferably 2 to 3 carbon atoms. Particularly preferred are 2 alkylene groups. s represents an integer, preferably 0 to 200, more preferably 0 to 100, still more preferably 0 to 70, particularly preferably 0 to 55. As the R _7, may be present only each alone, there may be two or more.

  Z in the chemical formula (1) represents an oxyalkylene group. Preferably, it is an oxyalkylene group having 2 to 6, more preferably 2 to 4, more preferably 2 to 3, and particularly preferably 2 carbon atoms. In addition, as Z, only 1 type may exist independently and 2 or more types may exist. q represents an integer, preferably an integer of 17 to 200, more preferably 18 to 100, still more preferably 28 to 70, and particularly preferably 34 to 55.

Furthermore, r in the chemical formula (1) is an integer, preferably 1 to 6, more preferably 1 or 2, and still more preferably 1. When r is 2 or _{more, -X p -Y- (Z q)} -OH may each be the same or may be different. In addition, when r is 2 or more, —X _p —Y— (Z _q ) —OH in the chemical formula (1) is bonded to carbon atoms having different Rs (the number of r) in the chemical formula (1). and means that are, -X p _-Y- (Z q) repeating structure as a repeating unit the moiety of _-OH is not intended to mean that the r followed.

  Among the compounds represented by the chemical formula (1), polyoxyalkylene alkyl ether is preferable from the viewpoint of suppressing the formation of a salt between an anionic surfactant and calcium in water. Such polyoxyalkylene alkyl ethers include polyoxyethylene alkyl ether, polyoxypropylene alkyl ether, polyoxyethylene polyoxypropylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxypropylene alkylphenyl ether, polyoxyethylene poly ether. And oxypropylene alkylphenyl ether. Among these, polyoxyethylene alkyl ether and polyoxyethylene alkyl phenyl ether are particularly preferable. The alkyl chain of the polyoxyalkylene alkyl ether preferably has 10 to 20 carbon atoms, more preferably 10 to 18, still more preferably 12 to 16, and particularly preferably 12 to 15.

  The cloud point when the component (b) is a 1% aqueous solution is preferably 100 ° C. or higher. A cloud point of 100 ° C. or higher is preferable because the hydrophilicity of the surfactant is increased and the solubility in water is improved. The cloud point can be measured by a generally known method.

  The mass ratio of the component (a) to the component (b) is (a) :( b) = 100: 0.1 to 100: 17. Within this range, formation of a salt of an anionic surfactant and calcium or magnesium in water is suppressed, which is preferable. When component (b) exceeds 17 mass% with respect to 100 mass% of component (a), the effect corresponding to the addition amount of component (b) may not be seen. In addition, in the case of a powder surfactant composition, it is necessary to add an excessive absorbent such as zeolite or porous inorganic salt in order to make powder, and the composition ratio of the surfactant is reduced. Therefore, the cleaning power may be reduced. In addition, increasing the amount of zeolite, etc. for powdering reduces the solubility of the surfactant composition in water. When used in detergents, the amount of undissolved detergent increases and causes stains. It becomes. More preferably, (a) :( b) = 100: 2 to 100: 16, more preferably (a) :( b) = 100: 4 to 100: 15, particularly preferably (a) :( b) = 100: 5 to 100: 12.

  Applications of the surfactant composition of the present invention include detergents, emulsifiers, solubilizers, antistatic agents, and dispersants for clothing, tableware, residential, hair, body, toothpaste, and automobiles. Etc. In view of the effects of the present invention, a preferred use is a detergent. The detergent can be used for clothing, tableware, dwelling, body, etc., but is preferably used as a clothing detergent. From the viewpoints of usage, usability, and functionality, known arbitrary components can be appropriately added to the surfactant composition.

  The surfactant of the present invention can be used as it is as a detergent for the above applications, or can be used as a detergent composition by appropriately adding necessary components according to the application. Therefore, the second embodiment of the present invention is a detergent composition.

  Although content (total) of a component (a) and a component (b) is not specifically limited as long as the effect of this invention is acquired, Preferably it is 1-40% with respect to 100% of liquid detergent composition. More preferably, it is 5-35%, More preferably, it is 10-30%. If it is this range, since a favorable cleaning effect is acquired, it is preferable.

  In the detergent composition, surfactants and additives other than the components (a) and (b) usually used in detergents can be used.

  The surfactant is at least one selected from anionic surfactants other than component (a), nonionic surfactants other than component (b), cationic surfactants and amphoteric surfactants, and these surfactants Can use 1 type (s) or 2 or more types.

  Anionic surfactants other than component (a) include alkyl ether sulfates, alkenyl ether sulfates, alkenyl sulfates, α-olefin sulfonates, α-sulfo fatty acids or ester salts thereof, alkane sulfonates, saturated fatty acids. Salt, unsaturated fatty acid salt, alkyl ether carboxylate, alkenyl ether carboxylate, amino acid type surfactant, N-acyl amino acid type surfactant, alkyl phosphate ester or salt thereof, alkenyl phosphate ester or salt thereof, etc. Is preferred.

  As the nonionic surfactant other than the component (b), higher fatty acid alkanolamides or alkylene oxide adducts thereof, sucrose fatty acid esters, alkyl glycoxides, fatty acid glycerin monoesters, alkyl amine oxides and the like are suitable.

  As the cationic surfactant, a quaternary ammonium salt or the like is suitable.

  As the amphoteric surfactant, a carboxyl type amphoteric surfactant, a sulfobetaine type amphoteric surfactant and the like are suitable.

  The blending ratio of the surfactant (total) including the components (a) and (b) is usually preferably 5 to 60% with respect to 100% of the detergent composition. More preferably, it is 5 to 50%, still more preferably 10 to 45%, and particularly preferably 10 to 40%. If it is this range, since a favorable cleaning effect is acquired, it is preferable.

  The detergent composition of the present invention preferably further contains a detergent builder as an additive. The term “builder” as used herein refers to a component that has a chelate ion exchange action, an alkali buffer action, a solid particle dispersion action, and the like, and that significantly improves detergent performance when combined with a surfactant. The builder that can be used in the present invention is not particularly limited as long as it has the effects of the present invention. For example, alkali builders such as carbonates, hydrogen carbonates, silicates, and bow glasses, tripolyphosphates, pyrophosphates, Nitrilotriacetate, ethylenediaminetetraacetate, citrate, (meth) acrylic acid copolymer salt, acrylic acid-maleic acid copolymer, fumarate, chelate builder such as zeolite, (meth) acrylic acid polymer Examples thereof include known polycarboxylates such as salts, acrylic acid-maleic acid copolymer salts and fumaric acid copolymer salts, and anti-redeposition agents such as carboxyl derivatives of polysaccharides such as carboxymethylcellulose. As the counter salt used for the builder, alkali metals such as sodium and potassium, ammonium, amine and the like can be used. In the case of a powder detergent, it is preferable to blend tripolyphosphate, pyrophosphate, and zeolite. In the case of a liquid detergent, it is preferable to mix nitrilotriacetate, ethylenediaminetetraacetate, and citric acid.

  Other additives include the above-mentioned builders, enzymes such as amylase, protease, lipase, and cellulase, stain inhibitors such as benzotriazole and ethylene-thiourea, soil release agents, color transfer inhibitors, softeners, and fragrances. , Solubilizers, fluorescent agents, colorants, foam stabilizers, polishes, bactericides, bleaching agents such as percarbonates, bleaching aids, dyes, solvents and the like.

  The blending ratio of the additive is usually 40 to 95%, more preferably 50 to 90%, further preferably 55 to 90%, particularly preferably 60 to 90% with respect to 100% of the detergent composition. . If the blending ratio of the additive is within this range, it is preferable because a good cleaning effect can be obtained and the long-term stability of the composition is also improved.

  The detergent composition is used only for specific applications such as synthetic detergents for household detergents, textile industry and other industrial detergents, hard surface cleaners, and bleaching detergents that enhance one of the components. Also includes detergent.

  The detergent composition of the present invention may be a solid detergent composition such as a powder detergent, a high bulk density detergent, a tablet detergent, or a liquid detergent composition. Any form of production can be produced using a conventionally known production method. For example, in the case of a powder detergent, the powder detergent composition is obtained by adding a surfactant or the like containing the components (a) and (b) to base granules obtained by slurrying the additive and spray drying. be able to.

  When the detergent composition is a liquid detergent composition, the amount of water contained in the liquid detergent composition is usually preferably 0.1 to 75%, more preferably 1 to 55, with respect to 100% of the liquid detergent composition. % Or less, and most preferably 1.5 to 50%.

  Even when the surfactant composition or the detergent composition is used in hard water having a high concentration of calcium ions and magnesium ions, the precipitation of salt is small and an excellent cleaning effect is obtained. That is, the third embodiment of the present invention is a method of washing using the surfactant composition or the detergent composition described above and water having a hardness of 100 mg / L (calcium carbonate equivalent) or more. As described above, the component (a) and calcium ions and magnesium ions contained in water used for washing form a salt, and this salt suppresses the washing effect of the component (a). is there. This is a particular problem in regions where the concentration of calcium contained in tap water is high, specifically in regions where the hardness is 100 mg / L or more. The problem can be solved by performing washing using the surfactant composition or the detergent composition.

  The surfactant composition and the detergent composition used in the washing method of the present embodiment are as described above. The amount of the surfactant composition and the detergent composition used at the time of washing is not particularly limited as long as the effect of the present invention can be obtained. Usually, in the case of a surfactant composition, Used at 0.1 g / L to 0.6 g / L. If it is the usage-amount of this range, it is preferable at points, such as a washability and the solubility of a detergent.

  In the present invention, the water used for washing has a hardness of 100 mg / L (calcium carbonate equivalent) or more, more preferably a hardness of 100 to 500 mg / L (calcium carbonate equivalent). In addition, the hardness as used in this invention points out the total hardness measured according to JISK0101.

  In the above method, as long as washing is performed with water having a hardness of 100 mg / L or more using the surfactant composition or the detergent composition, the means to be used (washing machine, hand washing, etc.), the number of washings, etc. are not limited.

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

(Example)
In water (pH 10) containing sodium dodecylbenzenesulfonate 200 mg / L and a hydrocarbon group-containing polyoxyalkylene compound having the structure and HLB value shown in Table 1 below as shown in Table 1, a calcium carbonate concentration of 610 mg / L A calcium chloride aqueous solution was added so as to have a hardness of L, and the calcium salt precipitation inhibiting ability was measured by the following method.
(1) First, pure water was added to 14.7 g of calcium chloride dihydrate to make 100 g, and a 1 mol / L calcium chloride aqueous solution was prepared.
(2) Pure water was added to 4.5 g of glycine and 3.5 g of sodium chloride to make 1,000 g to prepare a glycine buffer. The pH was adjusted to 10 with sodium hydroxide.
(3) Hydrocarbon group-containing polyoxyethylene alkyl ether was added to 2.0 g of sodium dodecylbenzenesulfonate at a ratio shown in Table 1, and pure water was added thereto to make 200 g to prepare a surfactant composition aqueous solution.
(4) 3.6 g of the glycine buffer solution of (2), and 1.8 g of the surfactant composition aqueous solution of (3) to make 90 g, and the sample is sufficiently stirred using a magnetic stirrer. A solution was prepared.
(5) The sample solution prepared in (4) was titrated with a 1 mol / L calcium chloride aqueous solution using an automatic drop device (main body: COM-550, luminous intensity unit; M-500) manufactured by Hiranuma Sangyo Co., Ltd. The transmittance of the aqueous solution was measured (wavelength: 650 nm). The titration amount of the calcium chloride aqueous solution was 0.55 ml, and the dropping speed was 0.025 ml / s.

  The results are shown in Table 1.

As shown in Table 1 above, the transmittances of the surfactant compositions of Examples 1 to 7 were higher than those of Comparative Examples 1 to 4, and Examples 1 to 7 Examples have shown that precipitation of calcium salts can be suppressed. From the above results, it was shown that the surfactant composition of the present invention suppresses precipitation of calcium salt even when water having high hardness is used.

Claims (6)

  (A) one or more selected from the group consisting of alkylbenzenesulfonic acid, alkylbenzenesulfonate, alkylsulfuric acid and alkylsulfate, and (b) carbon having 10 to 30 carbon atoms and having an oxyalkylene group A hydrocarbon group-containing polyoxyalkylene compound in which the total mass of polyoxyalkylene groups having 3 or less and hydroxyl groups is 75 to 95% with respect to 100% of the total mass of the compound, (a) and (b ) And a mass ratio of (a) :( b) = 100: 0.1 to 100: 17.   (A) one or more selected from the group consisting of alkylbenzene sulfonic acid, alkylbenzene sulfonate, alkyl sulfate and alkyl sulfate, and (b) a hydrocarbon group having 10 to 30 carbon atoms, and the HLB of Griffin is 15 A hydrocarbon group-containing polyoxyalkylene compound having a molecular weight of (a) and (b) of (a) :( b) = 100: 0.1 A surfactant composition that is 100: 17. The surfactant composition according to claim 1 or 2, wherein the hydrocarbon group-containing polyoxyalkylene compound is represented by the following chemical formula (1):

In the formula, R represents a linear or branched alkyl group or alkenyl group having 10 to 20 carbon atoms; X is

P is 0 or 1; Y is

In the formula, R _{1 to} R ₄ represent an alkylene group having 2 to 6 carbon atoms, R ₅ represents a hydrogen atom or a group represented by the following chemical formula (2);

In the formula, R ₆ and R ₇ represent an alkylene group having 2 to 6 carbon atoms, and s is an integer of 0 to 200:
Z represents an oxyalkylene group having 2 to 6 carbon atoms; q is an integer of 17 to 200; and r is an integer of 1 to 6.   The surfactant composition according to any one of claims 1 to 3, which contains 10 to 30% by mass of (a) based on the total amount of the composition.   The surfactant composition according to any one of claims 1 to 4, which is a detergent composition.   A washing method using the surfactant composition according to claim 5 and water having a hardness of 100 mg / L (calcium carbonate equivalent) or more.