JP2000109890A - Prewashing treatment composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition which has an excellent detergency to blackish stains in fibrous products, by incorporating therein a surface active agent selected from amine oxides and amphoteric surface active agents and an organic and/or inorganic acid with a specific pKa and setting the pH at a specific value. SOLUTION: An organic acid and/or an inorganic acid which have a pKa of 2.0-6.8 is used. The pH of an aqueous solution containing 1 wt.% of this composition is set at 2.0-6.8. As the amine oxide, that of formula I is preferred. In formula I, R1 is a 6-20C alkyl, alkenyl or β-hydroxyalkyl or an 8-24C alkyl or alkenyl including its ester, amide or ether split group; R2 is R1, a 1-3C alkyl or hydroxyalkyl; and R3 is a 1-3C alkyl or hydroxyalkyl. The amphoteric surface active agents preferably include those of formulae II and III. In the formulae, R4 and R7 have the same meaning as that of R1; R5 and R8 are each a 1-20C alkyl or β-hydroxyalkyl; R9 has the same meaning as that of R3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laundry pretreatment composition having excellent detergency for dark stains on textiles such as clothing.

2. Description of the Related Art Dark stains on textiles are one of the stains that are difficult to remove by ordinary washing. The cause of this dark stain is considered to be mainly dust, but it has been shown that the black component of dust is carbon black (Hario Mizushima, "Surface", 1968). This carbon black is obtained by incomplete combustion of various organic substances, and is basically a substance consisting of carbon, which is in the form of almost spherical particles of colloidal size. It is usually a body. In particular, in the vicinity of cities where automobile exhaust gas is high as in today, such carbon black is considered to be a major cause of darkening of fibers. Such dark stains do not adhere in a large amount in one wear unlike mud stains of socks, but gradually adhere in each wear and darken the fibers little by little. Therefore, if noticed, darkening stains become more noticeable as compared to new ones, but it is difficult to remove such darkening by ordinary washing. As a method of removing such dirt, improving the mechanical force at the time of washing can be cited. However, any further increase in the mechanical force will cause damage to clothing. In addition, since dirt is widespread, washing with hands is too burdensome, and in fact it is giving up. Therefore, although a cleaning agent and a cleaning method for effectively removing darkening without improving the mechanical force have been demanded, those which are actually satisfactory have not been found yet.

[0002] As a method for washing mud stains, which are different from dark stains but are representative of inorganic stains, a method of treating fibers under acidic conditions is also known. JP-A-60-212496
JP-A-60-212497 and JP-A-60-212497 disclose a method of washing by the action of cellulase under weakly acidic conditions.
No. 26797 discloses a method in which a phosphonic acid compound is allowed to act under weakly acidic conditions, and then mud stains are removed with an alkaline detergent. Although these methods are effective for removing mud particles as inorganic dirt, they do not show a sufficient cleaning effect on carbon dirt, which is a darkening component. Also, weakly acidic detergents containing amine oxides are disclosed in JP-A-1-266200, JP-A-64-40598, JP-A-5-19217, and the like. Further, JP-A-57-105495, JP-A-57-105496,
JP-A-57-105497 discloses an acidic liquid detergent composition for clothing capable of imparting flexibility to fibers by utilizing the property that amine oxide and betaine exhibit cationic properties under acidic conditions and exhibit a softening effect. It is shown. However,
All of these are used solely as detergents, and do not exhibit sufficient detergency especially for dark stains on textiles.

Further, JP-A-6-207196, JP-A-7-126694, JP-A-7-34094 and JP-A-6-184594 disclose a liquid bleach containing hydrogen peroxide and an amine as a cleaning aid. An example incorporating an oxide is also shown as an example. In such a liquid bleach containing hydrogen peroxide, since the hydrogen peroxide is unstable under alkaline conditions, the composition is made acidic and used as an acidic cleaning agent for removing stains on hard surfaces, or as a bleaching agent. There is known a use method in which a textile product is washed and bleached after mixing with an alkali-containing clothing detergent in order to exert the effect.
However, for stains derived from foods such as black spots, the stains are bleached by the oxidizing action of the bleaching agent.However, in the dark stains, carbon is the main component. It is difficult to remove. As described above, although a wide variety of cleaning agents and bleaching agents are known, a cleaning agent and a cleaning method having a satisfactory cleaning effect on dark stains are not known.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a laundry pretreatment composition having excellent detergency against dark stains on textiles such as clothing.

Means for Solving the Problems The present inventors have intensively studied and, by pre-treating a fiber product with an amine oxide showing a cationic property under an acidic condition and an amphoteric surfactant, the present invention is excellent in preventing dark stains. The present inventors have found that a good cleaning effect can be obtained, and have reached the present invention. That is, the present invention relates to (a) at least one surfactant selected from the group consisting of amine oxides and amphoteric surfactants, and (b) a pKa of 2.0 to 6.8.
Containing an organic acid and / or an inorganic acid having a pKa of 2.0 to 6.8,
The present invention provides a laundry pretreatment composition, wherein the pH of a 1% by weight aqueous solution of the composition is 2.0 to 6.8.

BEST MODE FOR CARRYING OUT THE INVENTION The present invention utilizes the property that the ionized state of an amine oxide or an amphoteric surfactant varies depending on the pH of an aqueous solution. This is an acidic laundry pretreatment composition for removing from clothing and textiles by a completely different washing mechanism. That is, the amine oxide or amphoteric surfactant included in the present invention utilizes the fact that the chemical equilibrium represented by the following formula exists.

[0005]

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That is, the amine oxide exhibits cationicity under acidic conditions and nonionicity under alkaline conditions,
Amphoteric surfactants are cationic under acidic conditions and anionic under alkaline conditions. Utilizing this property, these surfactants are adsorbed under acidic conditions by increasing the electrostatic affinity of these surfactants to the fiber surface or dark spots. Next, the dispersibility of dark stains is increased by the action of a detergent containing an anionic surfactant. Since both the anionic surfactant and the fiber surface have a negative charge in the aqueous solution, they both repel electrostatically, and the aggregate of the surfactant adsorbed on the dark stains is easily detached from the fiber surface. It is considered to show an epoch-making detergency.
Therefore, it is necessary to adsorb these surfactants to dark stains for a certain period of time under a condition of pH less than 7.0, and then wash them with a detergent containing an anionic surfactant to effectively remove dark stains. Can be. The amine oxide as the component (a) of the present invention has the following general formula (1)
Is preferably represented by

[0007]

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In the formula, R ₁ is a linear or branched alkyl, alkenyl or β-hydroxyalkyl group having 6 to 20, preferably 8 to 18 and particularly preferably 10 to 16 carbon atoms, or an ester group. And an alkyl or alkenyl group having 8 to 24 carbon atoms, preferably 10 to 20 carbon atoms, particularly preferably 12 to 18 carbon atoms, including a splitting group split by an amide group or an ether group. Among them, a linear alkyl group is preferable. R ₂ is a linear or branched alkyl group, alkenyl group or β-hydroxyalkyl group having 6 to 20, preferably 8 to 18, and particularly preferably 10 to 16 carbon atoms, or an ester group, an amide group or an ether group. Represents an alkyl group or alkenyl group having 8 to 24, preferably 10 to 20, particularly preferably 12 to 18 carbon atoms, or an alkyl group or hydroxyalkyl group having 1 to 3 carbon atoms, including the splitting group split by the above. Among them, an alkyl group having 1 to 3 carbon atoms is preferable. R ₃ has 1 carbon atom
Represents an alkyl group or a hydroxyalkyl group. Among them, an alkyl group having 1 to 2 carbon atoms is preferable.
Further, the amphoteric surfactant used as the component (a) of the present invention is preferably represented by the following general formula (2) or (3).

[0009]

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Wherein R ₄ and R _{7 each} have 6 to 20 carbon atoms;
Preferably 8 to 18, particularly preferably 10 to 16, linear or branched alkyl or alkenyl groups or β-
Having 8 to 8 carbon atoms including a hydroxyalkyl group, or a splitting group split by an ester group, an amide group or an ether group;
24, preferably 10-20, particularly preferably 12-1
8 represents a linear or branched alkyl or alkenyl group. R ₅ and R _{8 each} have 1 to 20 carbon atoms, preferably 1 to
10, particularly preferably 1 to 3, of a linear or branched alkyl group or β-hydroxyalkyl group. R ₆ and R ₉ represent an alkyl group having 1 to 3 carbon atoms or a β-hydroxyalkyl group. X represents a hydrogen atom or a hydroxyl group. Of the above amine oxides and amphoteric surfactants,
A particularly preferred surfactant is an amine oxide. These surfactants can be basically produced by a known method. Other examples include α-trimethylammonio fatty acid, alkylaminopropionic acid, and alkyltaurine salts. The amount of the surfactant of the present invention represented by the formulas (1) to (3) is 0.1 to 60% by weight, preferably 4% by weight.
-50% by weight, particularly preferably 6-20% by weight.

The pH of the laundry pretreatment composition of the present invention when diluted to 1% by weight is 2.0 to 6.8, more preferably 3.0 to 3.0%.
To 6.5, more preferably 4.0 to 6.0. That is, the present invention relates to an organic acid having a pKa of 2.0 to 6.8 and a pKa of 2.0 to 6.8 in an amount for adjusting the pH of a 0.1% by weight diluted aqueous solution to this range.
Containing an inorganic acid. These acid components act as pH buffering agents, and the inclusion of such acid components reduces the change in pH before and after dilution of the composition.
Therefore, even when the composition is allowed to act directly on the soiled portion, or when diluted with water, the composition is maintained in a pH range showing a good cleaning effect. When pH becomes equal to pKa, p
Since the H buffering action is the highest, the pKa range of the organic acid and the inorganic acid in the present invention is from 2.0 to 6.8, preferably from 2.5 to 6.5, and more preferably from 3.0 to 6.0. Further, as for the organic acid and the inorganic acid which are dissociated in multiple stages, the buffering action is expected if any of the pKa is within a predetermined range. Therefore, the pKa of all dissociation stages need not be within this range. Organic acids having a pKa of 2.0 to 6.8 include benzoic acid, citric acid, malic acid, tartaric acid, glycolic acid, β-
Oxybutyric acid, tartroic acid, tricarbaric acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, muconic acid, aconitic acid, formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthylic acid, caprylic acid Acids, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, speric acid, azelaic acid and sebacic acid. Further, a phosphonic acid such as 1-hydroxyethane-1,1-diphosphonic acid, an aminocarboxylic acid such as ethylenediaminetetraacetic acid, or a mixture of these acids and a water-soluble salt thereof can be used. Of these, benzoic acid and citric acid are preferred. pKa2.0-6.
Examples of the inorganic acid 8 include phosphoric acid, pyrophosphoric acid and tripolyphosphoric acid. Of these, tripolyphosphoric acid is preferred. If necessary, the pH is adjusted to the above-mentioned range using caustic soda, caustic potash, sodium carbonate, sodium bicarbonate, alkanolamines such as monoethanolamine and diethanolamine, and alkali agents such as silicates.

The following components can be added to the laundry pretreatment composition of the present invention, if desired, as long as the cleaning effect is not impaired: nonionic surfactant, anionic surfactant, cationic interface Activator; Metal chelating agent; Hydrotrope such as ethanol and lower alkylaryl sulfonic acid; Hydrogen peroxide and JP-A-5-205, which can suppress generation of chlorine gas even when mixed with a chlorine-based detergent by mistake. Known chlorine gas generation inhibitors as disclosed in JP-A-111546; enzymes such as proteases, lipases and cellulases; and optical brighteners, preservatives, dyes, fragrances,
Glue, etc. In order to suppress the generation of chlorine gas, a hydrogen peroxide content of 4.5% by weight is sufficient. Further, when chlorine gas is not generated even when mixed with a chlorine-based bleaching agent, such as when the composition has a pH of 6 or more, it is not necessary to particularly add the compound.

[0013] The anionic surfactant is preferably added in an amount less than the equivalent amount to the total amount of the amine oxide and / or amphoteric surfactant, since the detergency is improved.
On the other hand, nonionic surfactants can coexist for the purpose of improving the permeability to the cloth to be washed and the cleaning power of sebum dirt, and the like. The following are specific examples of such nonionic surfactants. A polyoxyalkylene alkyl or alkenyl ether obtained by adding an average of 4 to 18 moles of ethylene oxide (EO) and / or propylene oxide (PO) to a primary or secondary alcohol having 8 to 18 carbon atoms; Polyoxyethylene alkyl phenyl ether having an average of 4 to 20 moles of ethylene oxide having an alkyl group of from 12 to 12; a product obtained by adding ethylene oxide to a condensate of propylene oxide and propylene glycol (pluronic surfactant);
A product obtained by adding ethylene oxide to a condensate of propylene oxide and ethylenediamine (tetronic surfactant); a fatty acid having 8 to 22 carbon atoms and ethylene oxide (EO) and / or propylene oxide (PO)
A polyoxyalkylene alkyl or alkenyl fatty acid ester or a lower alcohol ether thereof having an average of 4 to 18 moles added thereto; a polyoxyethylene alkylphenyl having an alkyl group having an average of 6 to 12 carbon atoms and having an average of 5 to 20 moles of ethylene oxide added thereto Ethers; esters of fatty acids having an average of 10 to 20 carbon atoms with sucrose; fatty acid glycerin monoesters having an average of 10 to 20 carbon atoms; and alkyl polyglucosides having 8 to 20 carbon atoms.

These alkyl or alkenyl groups may be linear or branched. A nonionic surfactant obtained by adding ethylene oxyside or propylene oxide can be synthesized by an ordinary method using an alkali catalyst (such as NaOH), or a method described in JP-A-1-164337. , An alcohol alkoxylate having a narrow alkylene oxide addition molar distribution using a non-strongly basic alkoxylation catalyst. A preferred nonionic surfactant used in the present invention is an alcohol ethoxylate having a narrow ethylene oxide addition molar distribution obtained by using a non-strongly basic alkoxylation catalyst or the like. The pretreatment composition for washing of the present invention may be liquid, powder, or paste, and is not particularly limited, but is preferably liquid. However, in each case, dissolve in pure water
It is necessary that the aqueous solution when adjusted to the weight% has an acidity of pH 2.0 to 6.8.

When the acidic laundry pretreatment composition of the present invention is used, the preferred concentration of the amine oxide and / or amphoteric surfactant in the composition depends on the method of using the pretreatment composition. When a liquid or paste-like composition is directly applied to the fibers, a sufficient cleaning effect is exhibited when the concentration of these surfactants in the liquid composition is 0.01% by weight or more. When the composition is dissolved in water and the textile is immersed, the concentration of these surfactants in the washing bath must be at least 1% by weight or more. 0.1 when directly applied to fiber
A concentration of at least 1% by weight is preferred, and a concentration of at least 1% by weight is particularly preferred. On the other hand, when immersing, a concentration of 1 to 50% by weight and a concentration of 6 to 20% by weight are preferable. The pretreatment method using the pretreatment composition for washing in the present invention is not particularly limited, but specific examples are shown below. 1) In a bucket or the like, the pretreatment agent composition of the present invention is dissolved in water or lukewarm water in advance, and the textile is immersed in the aqueous solution for a predetermined time, and then a washing liquid (washing) in which a detergent containing an anionic surfactant is dissolved. Transfer to the machine) and wash. 2) The pretreatment agent composition of the present invention is dissolved in water or lukewarm water collected in a washing machine, and the textile is immersed in the aqueous solution for a predetermined time. Then, a detergent containing an anionic surfactant is added thereto, and washing is performed. 3) When the pretreatment agent composition of the present invention is in the form of a liquid or paste, it is applied directly to a particularly dirty portion of a textile,
Transfer to a washing liquid (in a washing machine) in which a commercially available detergent containing an anionic surfactant is dissolved, and wash. 4) When the pretreatment agent composition of the present invention is in a powder or solid form, the pretreatment agent composition is dissolved in water or lukewarm water in advance, and the solution is directly applied to a particularly dirty portion of a textile, and then anionic interface Transfer to a washing liquid (in a washing machine) in which a commercially available detergent containing an activator is dissolved, and wash. 5) Put the textile in cold or lukewarm water collected in a washing machine, add the pretreatment composition of the present invention while rotating the washing machine and dissolve it. Washing is performed by adding a detergent containing the agent.

Although the above-mentioned methods are mentioned as specific examples, the present invention is not limited to these methods. That is, by treating with the pretreatment agent composition of the present invention and leaving it to stand for a predetermined time and then washing it with the anionic surfactant-containing washing liquid, an excellent cleaning effect against dark stains can be obtained. In the present invention, the detergent used at the time of washing (main washing) after the pretreatment with the laundry pretreatment composition is preferably a detergent containing at least an anionic surfactant. Specific examples of the anionic surfactant contained in the detergent for the main cleaning are shown below. 1) an alkylbenzene sulfonate having an alkyl group having 8 to 16 carbon atoms 2) an alkyl sulfate having 10 to 20 carbon atoms 3) an α-olefin sulfonate having 10 to 20 carbon atoms 4) an alkane having 10 to 20 carbon atoms Sulfonates 5) Alkyl ether sulfates or alkenyl ether sulfates having a linear or branched alkyl or alkenyl group having 10 to 20 carbon atoms and having an average of 0.5 to 8 mol of ethylene oxide added thereto 6) Having an alkyl group having 10 to 20 carbon atoms, and having an average of 0.1.
Polyoxyethylene alkylphenol ether sulfate to which 5 to 8 mol of ethylene oxide is added 7) α-sulfofatty acid ester salt having an alkyl group having 10 to 20 carbon atoms 8) Alkyl or alkenyl group having 10 to 22 carbon atoms Fatty acid salt 9) Alkyl ether fatty acid salt or alkenyl ether fatty acid salt having a linear or branched alkyl or alkenyl group having 10 to 20 carbon atoms and having an average of 0.5 to 8 mol of ethylene oxide added thereto 10) Carbon Having an average of 0.1 to 10 having an alkyl group of 10 to 20;
Polyoxyethylene alkylphenol ether fatty acid salt to which 5 to 8 mol of ethylene oxide is added Among these, preferred are anionic surfactants having a strongly acidic group such as a sulfonic acid group as described in 1) to 7). .

[0017]

According to the present invention, the use of amine oxides and / or amphoteric surfactants which exhibit cationicity under acidic conditions enables pretreatment for washing to exhibit excellent detergency against dark stains on textiles. Agent composition can be obtained.

EXAMPLES Next, the present invention will be described in more detail with reference to examples. Prior to this, a method for evaluating the cleaning power of dark stains used in the examples will be described. (1) Preparation method of darkened stained cloth As the darkened stained cloth, artificial darkened stained cloth (cotton) and darkened curtain (polyester) shown in (A) and (B) below.
Were used. (A) Artificial darkened stained cloth: EMPA10 manufactured by EMPA
1 was used as an artificial darkened soiled cloth. This is an artificially contaminated cloth in which carbon is attached to cotton cloth using olive oil as a medium.
This was cut into 5 cm × 5 cm, and those having a reflectance in the range of 15 ± 2% were provided to the stained cloth. (B) Darkened curtain: A darkened lace curtain was used for about 4 years in a household in Kawasaki city. This curtain is a plain weave white lace curtain (180 cm wide x 190 cm high) with 100% polyester display, and is washed at home every six months using a commercially available laundry detergent and a fully automatic washing machine. After about 5 months hanging over the window, overall darkening was observed. This is 5cm x 5c
m, and sew the outer shell to prevent fraying during washing,
Those having a reflectivity in the range of 42 ± 2% were used for the stained cloth.

(2) Preparation of pre-washing treatment composition The pre-washing treatment composition was prepared as in Examples and Comparative Examples shown in Tables 1-3. Regarding the pH of the composition, the pH of an aqueous solution (1% by weight aqueous solution of the composition) in which 1 gram of the composition is dissolved in 99 gram of water indicates a predetermined pH.
It was prepared by previously adding NaOH or monoethanolamine to the composition. In Tables 1-3, the pH described following the composition of the pretreatment agent indicates the pH of the 1% by weight aqueous solution. (3) Washing method (immersion washing) Using a Terg-O-Tometer manufactured by USTesting, 0.9 g of the laundry pretreatment composition of the present invention was dissolved in 900 ml of water at 3 ° DH and 25 ° C in a washing tank. A treatment liquid was used.
Next, knitted cloth was added to 10 contaminated cloths to make a total of 30 g, which was immersed in the pretreatment liquid for a predetermined time (this time is referred to as immersion time). The immersion was performed in a constant temperature bath to avoid a change in water temperature during the immersion. After soaking for a predetermined time,
1 g of a detergent (anionic, nonionic or cationic surfactant) was added to the immersion liquid, and washed at 120 rpm for 10 minutes. Thereafter, it was rinsed with 3 ゜ DH and 900 ml of water for 3 minutes, dehydrated in a two-tub washing machine, and air-dried. Tables 1 and 2 show the results.
Shown in (Applying and washing) About 1 ml of the laundry pretreatment composition of the present invention shown in Tables 1 and 2 was applied to five stained cloths, left for 60 minutes, and then contained a commercially available detergent (Super Top, manufactured by Lion Corporation). The laundry was washed with 15 g / 30 L of a detergent solution. Table 3 shows the results. (4) Evaluation method The detergency was determined by the formula-1.

[0019]

(Equation 1) K / S = (1−R ÷ 100) ² ÷ (2R ÷ 100) (Equation of Kubelka-Munk) Here, R is a reflectance (%) measured by an ELREPHO reflectometer manufactured by Carl Twice. is there.

The description of each component used in Tables 1-3 is shown below. (5) Components of pretreatment agent for washing Amine oxide-1; Lauryl dimethylamine oxide Amine oxide-2; Alkyl dimethylamine oxide having an alkyl group of C12 to C14 Amine oxide-3; Monohydrogenated tallow alkyl dimethylamine oxide Amine oxide -4; Amidopropylamine oxide laurate betaine-1; Betaine lauryl dimethylaminoacetate (Lebon LD-36, manufactured by Sanyo Chemical Co., Ltd.) (6) Main component of detergent Anionic surfactant-containing detergent: linear alkyl (C _{10 to} C
₁₄ ) Sodium benzenesulfonate Nonionic surfactant-containing detergent: alcohol ethoxylate with an average of 9 moles of ethylene oxide added per mole of lauryl alcohol Detergent containing cationic surfactant: monoalkyl (C ₁₈ ) trimethylammonium chloride (7) Organic acid pKa Lactic acid: 3.66 Citric acid: 4.35 Benzoic acid: 4.20 HEDP (1-hydroxyethane-1,1-diphosphonic acid): 2.5

[0021]

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[0022]

[Table 1] Table 1 Immersion cleaning (Example)  Example 1 2 3 4 5 6 7 (Pre-treatment) Composition of laundry pre-treatment agent (% by weight) 4---10---Betaine-1----10--Lactic acid 1--1---Citric acid-1--1--Benzoic acid--1-----HEDP----- 1 1 Fragrance 0.1 0.1 0.1 0.1 0.1 0.1 0.1 pH adjuster qs qq qq qq qq qq qqWater Remaining Remaining Remaining Remaining Remaining Remaining Remaining Remaining Remaining pH 5.0 5.5 4.0 6.0 3.0 4.5 6.5 Immersion time (min) 60 60 60 60 60 60 60 (Washing) Detergent composition (% by weight) Anion 20 10 10 5 5 10-Nonionic--10 20--20 Cation---2---Sodium hydroxide Appropriate amountWater Remaining Remaining Remaining Remaining Remaining Remaining Remaining Remaining Remaining PH of the washing liquid 77 77 77 77 77 Detergency (%) Artificial black cloth 60 58 59 55 53 54 52Darkening curtain 44 40 42 39 37 39 39 36

[0023]

[Table 2] Table 2 Immersion cleaning (comparative example) Comparative Example 1 2 3 4 5 (Pretreatment) Composition of laundry pretreatment agent (% by weight) Amine oxide -2 10--10 10 Alcohol ethoxylate-10---LAS-Na--10--Betaine-1- ----Lactic acid 5----Citric acid-1-1-Benzoic acid--1--HEDP------Fragrance 0.1 0.1 0.1--pH adjuster qs qs qs qs qs qs qs water balance Amount Remaining amount Remaining amount pH 4.0 3.0 4.0 1.5 8.0 Soaking time 60 60 60 60 60 (Main washing) Detergent composition Anion 20 20 20 20 20 Sodium hydroxide Appropriate amount Appropriate amount Appropriate amount-Sulfuric acid-----Appropriate amount Water Remaining amount Remaining Remaining Remaining Remaining pH 7 7 7 7 7 Detergency (%) Artificial black cloth 56 43 41 45 43 Black curtain 39 30 30 37 32

[0024]

TABLE 3 Table 3 applied washed embodiment Sample No. 8 9 10 11 12 13 14 (Pretreatment) Composition of laundry pretreatment agent (% by weight) Amine oxide- 11 ---- 13 Amine oxide-2-2-2 ---- --- Amine oxide-3 ---- 2 ----Amine oxide-4---0.5---Betaine-1----31 -Phenoxyethanol-11-----Lactic acid 1--1----Citric acid-1--1-- Benzoic acid − − 1 − − − − HEDP − − − − − − 1 1 Fragrance 0.1 0.1 0.1 0.1 0.1 0.1 0.1 pH adjuster Appropriate amount Appropriate amount Appropriate amount Appropriate amount Appropriate amount Appropriate amount Water remaining Remaining Remaining Remaining Remaining Remaining pH 5.0 5.5 4.0 6.0 3.0 4.5 6.5 Standing time (min) 60 60 60 60 60 60 60 (Main washing) pH of washing liquid 10.4 10.4 10.4 10.4 10.4 10.4 10.4 Detergency (%) Artificial black cloth 60 59 57 57 53 56 53

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C11D 17/08 C11D 17/08

Claims (1)

[Claims] 1. A surfactant selected from the group consisting of (a) an amine oxide and an amphoteric surfactant, and (b) an organic acid having a pKa of 2.0 to 6.8 and / or a pKa of 2.0 to 6.8.
PH of a 1% by weight aqueous solution of the composition containing an inorganic acid of 6.8
Is from 2.0 to 6.8.