JP6624716B2 - α-Sulfo fatty acid ester salt-containing liquid - Google Patents

Description

  The present invention relates to a liquid containing an α-sulfofatty acid ester salt.

Conventionally, α-sulfo fatty acid ester salts (α-SF salts) are distributed in the form of solids (flakes, powders, and the like) and are mainly used as a washing component of powder detergents. However, when the α-SF salt is used in the liquid detergent, a liquid in which flake-form α-SF salt solids are dissolved or dispersed in water or the like is prepared before being mixed in the main mixing tank. Needed.

As a cleaning component of the cleaning agent, a linear alkylbenzene sulfonate (LAS), a polyoxyethylene alkyl ether sulfate (AES), and the like are widely used in addition to the α-SF salt. These LAS and AES have already been distributed in the form of highly concentrated liquid (concentrated liquid).
It is preferable from the viewpoint of efficiency that the α-SF salt aqueous solution can be used or stored at a high concentration, but in the case of the α-SF salt alone aqueous solution, the viscosity increases as the concentration increases, and the concentration is about 30% by mass. As a result, a hexagonal structure is formed and a gel state is obtained in which fluidity is lost.

  On the other hand, as a method for improving the fluidity of a high-concentration α-SF salt aqueous solution, Examples of Patent Document 1 include powders of α-sulfofatty acid methyl ester sodium salt having a fatty acid composition of 14 to 16 carbon atoms. And a method of preparing an α-SF salt aqueous solution by dissolving a solution of a fatty acid polyoxyethylene (EOp = 15) methyl ether having 18 carbon atoms in water at a predetermined ratio.

JP-A-6-128588

  According to the findings of the present inventors, the α-SF salt aqueous solution prepared by the above-described method described in Patent Document 1 may cause separation or precipitation when left standing and stored, and such separation or precipitation may occur. The resulting α-SF salt aqueous solution has a non-uniform fatty acid composition in the liquid.

  It is an object of the present invention to provide an α-sulfofatty acid ester salt-containing liquid in which the uniformity of the liquid is kept good even when the liquid is left standing and the separation and precipitation hardly occur.

The α-sulfofatty acid ester salt-containing liquid of the present invention comprises an α-sulfofatty acid ester salt (a) having a fatty acid residue having 16 to 18 carbon atoms, a fatty acid polyoxyalkylene alkyl ether (b), and water. Contains
The total content of (a) and (b) is more than 30% by mass and 40% by mass or less, and the mass ratio of (a) / (b) is 1.5 or more and 9.0 or less. I do.

  According to the present invention, an α-sulfofatty acid ester salt-containing liquid can be obtained in which the uniformity of the liquid is kept good even when the liquid is left standing and the separation and precipitation hardly occur.

The liquid containing an α-sulfofatty acid ester salt of the present invention comprises: (a) a component: an α-sulfofatty acid ester salt having 16 to 18 carbon atoms in a fatty acid residue; and (b) a component: a fatty acid polyoxyalkylene alkyl ether. , Water and water.
<Component (a): α-sulfofatty acid ester salt having 16 to 18 carbon atoms in the fatty acid residue>
The α-sulfofatty acid ester salt (α-SF salt) is obtained by a known production method, for example, using a tank-type reactor equipped with a stirrer or the like according to a conventional method, and converting the raw material fatty acid ester to sulfuric anhydride or the like. An α-sulfofatty acid ester (α-SF acid) is prepared by contacting and sulfonating, and then obtained by neutralizing the α-SF acid with sodium hydroxide or the like. it can. In addition, before and after neutralization, bleached with hydrogen peroxide or the like may be used.

  The component (a) is represented by the following general formula (I).

[Wherein, R ¹ is a hydrocarbon group having 14 to 16 carbon atoms, R ² is a hydrocarbon group having 1 to 6 carbon atoms, and M is a counter ion. In the formula (I), the hydrocarbon group for R ¹ may be linear or branched, or may have a cyclic structure. Among them, the hydrocarbon group for R ¹ is preferably an aliphatic hydrocarbon group, more preferably a straight-chain or branched-chain alkyl group, or a straight-chain or branched-chain alkenyl group. Alkyl groups and linear alkenyl groups are more preferred. R ¹ has 14 to 16 carbon atoms. When the carbon number of R ¹ is 14 or more, the surface activity is enhanced, and the detergency as a cleaning component is improved. On the other hand, when the carbon number of R ¹ is 16 or less, the appearance stability of the α-sulfofatty acid ester salt-containing liquid is improved.

In the formula (I), the hydrocarbon group of R ² may be linear or branched, or may have a cyclic structure. Among them, the hydrocarbon group for R ² is preferably an aliphatic hydrocarbon group, and more preferably a straight-chain or branched-chain alkyl group, or a straight-chain or branched-chain alkenyl group. And a branched alkyl group are more preferred. R ² has 1 to 6 carbon atoms, preferably 1 to 3. Examples of the hydrocarbon group for R ² include a methyl group, an ethyl group, an n-propyl group, and an isopropyl group. Since the detergency as a cleaning component is further improved, a methyl group, an ethyl group, and an n-propyl group are preferred. Preferably, a methyl group is particularly preferred.

In the above formula (I), M is a counter ion, and may be any as long as it can form a water-soluble salt with R ¹ CH (COOR ² ) SO ₃ ^— . Examples of the counter ion include an alkali metal ion, a protonated amine, and ammonium. Examples of the alkali metal that can be the counter ion include sodium and the like.

  The amine that can be the counter ion may be any of primary to tertiary amines, and preferably has a total carbon number of 1 to 6. The amine may have a hydroxy group, and preferably has a hydroxy group because the solubility of the α-sulfofatty acid ester salt-containing liquid in water under low-temperature conditions increases. Examples of such an amine include alkanolamines, and the alkanol group preferably has 1 to 3 carbon atoms. Specific examples of the alkanolamine include monoethanolamine, diethanolamine, and triethanolamine.

M is preferably an alkali metal ion, particularly preferably a sodium ion, because it is easily available and the appearance stability of the α-sulfofatty acid ester salt-containing liquid is improved.

Among the components (a), R ¹ in the formula (I) is a linear or branched alkyl group having 14 to 16 carbon atoms, or a linear or branched alkenyl group, Compounds in which ² is a methyl group are particularly preferred.
As the component (a), one type may be used alone, or two or more types may be used in appropriate combination. As the component (a), a mixture of different fatty acid residues (referred to as an acyl group portion) having different numbers of carbon atoms may be used because the detergency as a cleaning component is increased and the solubility in water is increased. preferable. Specifically, α-SF salt (C16) in which R ¹ in the formula (I) is a hydrocarbon group having 14 carbon atoms, and α-SF salt (C18) in which R ¹ is a hydrocarbon group having 16 carbon atoms ) Are preferably used. The mixing ratio (mass ratio) of C16 and C18 is preferably C16: C18 = 45: 55 to 95: 5, more preferably 60:40 to 90:10, and further preferably 80:20 to 85:15. When the mass ratio is within the above-mentioned preferred range, the detergency, the solubility in water, and the appearance stability are further improved.

In the α-sulfofatty acid ester salt-containing liquid of the present invention, the content of the component (a) is 18 to 36% by mass, preferably 23 to 36% by mass, based on the total mass of the α-sulfofatty acid ester salt-containing solution. %, More preferably 25 to 32% by mass.
When the content of the component (a) is at least the lower limit, the effects of the present invention will be remarkably exhibited. On the other hand, when the content of the component (a) is equal to or less than the upper limit, the uniformity of the liquid is easily maintained well, and separation and precipitation hardly occur.
The α-sulfofatty acid ester salt-containing liquid of the present invention may contain another α-SF salt other than the α-sulfofatty acid ester salt (a) in which the fatty acid residue has 16 to 18 carbon atoms. As the other α-SF salt, those having 12 to 14 carbon atoms in the fatty acid residue are preferable. As the α-SF salt, the effect of the present invention is more exerted, and the detergency is increased as a cleaning component. 67% or more, preferably 80% or more, more preferably 90% or more, and may be 100% with respect to the total mass of
In the α-sulfofatty acid ester salt-containing solution of the present invention, by containing an α-sulfofatty acid ester salt having 12 to 14 carbon atoms in the fatty acid residue, the appearance stability of the α-sulfofatty acid ester salt-containing solution and Fluidity is further improved.
<(B) component: fatty acid polyoxyalkylene alkyl ether>
Fatty acid polyoxyalkylene alkyl ethers are obtained by a known production method, for example, a method in which an alkylene oxide is addition-polymerized to a fatty acid alkyl ester using a surface-modified composite metal oxide catalyst (Japanese Patent Application Laid-Open No. 2000-144179). It can be easily manufactured according to the publication. Preferable examples of the surface-modified composite metal oxide catalyst include, specifically, metal ions (Al ³⁺ , Ga ³⁺ , In ³⁺ , Tl ³⁺ , and Co ³⁾ surface-modified with a metal hydroxide or the like. ³⁺ , Sc ³⁺ , La ³⁺ , Mn ^2+, etc.) complex metal oxide catalysts such as magnesium oxide to which magnesium oxide or the like is added, or hydrotalcite calcined catalysts surface-modified with metal hydroxides and / or metal alkoxides. is there.

Further, in the surface modification of the composite metal oxide catalyst, the mixing ratio of the composite metal oxide and the metal hydroxide and / or metal alkoxide is adjusted to 100 parts by mass of the composite metal oxide with respect to the metal hydroxide. The ratio of the substance and / or metal alkoxide is preferably 0.5 to 10 parts by mass, more preferably 1 to 5 parts by mass.

As the component (b), a compound represented by the following general formula (II) is preferable.

 R³-CO (OR⁴) MOR⁵... (II)


[Wherein, R³Is a saturated or unsaturated hydrocarbon group having 9 to 18 carbon atoms;⁴Is a hydrocarbon group having 2 to 4 carbon atoms;⁵Represents a hydrocarbon group having 1 to 3 carbon atoms, m represents an average number of moles of alkylene oxide added, and is 5 to 25. ]
In the above formula (II), R³Is a saturated or unsaturated hydrocarbon group having 9 to 18 carbon atoms. When the carbon number is within the above range, the cleaning performance and the appearance stability are excellent. The saturated or unsaturated hydrocarbon group preferably has 10 to 18 carbon atoms, and more preferably 11 to 17 carbon atoms. The saturated or unsaturated hydrocarbon group is preferably linear or branched, respectively. Among them, R in the formula (II)³Is a fatty acid polyoxyethylene methyl ether having a straight-chain alkyl group having 11 or 13 carbon atoms, and R in the formula (II)³Is preferably a fatty acid polyoxyethylene methyl ether which is an unsaturated hydrocarbon group having 18 carbon atoms derived from palm oil, and R in the formula (II)³Is particularly preferred in view of fluidity.

R ⁴ is an alkylene group having 2 to ⁴ carbon atoms, preferably an ethylene group or a propylene group. A plurality of R ⁴ in the formula may be the same or different. That is, as the alkylene group for R ⁴ , only one type may be used alone, or a plurality of types may be used in combination. For example, the alkylene oxide (OR ⁴ ) in the formula may be a mixture of EO and PO.

A method of adding OR ⁴ when combining a plurality of kinds is not particularly limited, for example, the addition method in the case of containing EO and PO may be, for example, random addition, or a block addition. Examples of the block adding method include a method of adding PO after adding EO, a method of adding EO after adding PO, a method of adding PO after adding EO, and a method of further adding EO. Is mentioned.

(B) component may foaming during cleaning, because it is inexpensive, or a EO adduct of m OR ⁴ in the formula are all EO, or the m OR ⁴ in the formula EO It is preferably an EO / PO adduct that is a mixture of and PO.

  m represents the average number of moles of alkylene oxide added, and is 5 to 25. When m is within the above range, the detergency, especially the detergency for sebum dirt, is improved. Further, the solubility of the detergent composition is improved.

In the case of an EO adduct, m is preferably 10 to 20, more preferably 12 to 20, and particularly preferably 12 to 18. When m is 10 or more, the effect of suppressing the separation of the liquid containing the α-sulfofatty acid ester salt or modifying hexagonal into a micelle phase is high.
R ⁵ is an alkyl group having 1 to 3 carbon atoms, and is preferably a methyl group from the viewpoint of cleaning performance.
In the component (b), the narrow ratio indicating the distribution ratio of the alkylene oxide adduct having different addition mole numbers of the alkylene oxide is usually 20% by mass or more and 80% by mass or less.

  The higher the narrow ratio, the better the detergency. Further, when the narrow ratio is 20% by mass or more, particularly 30% by mass or more, a liquid detergent composition having a small amount of raw material odor of a surfactant is easily obtained. This is because, after the production of the component (b), the amount of the fatty acid ester, which is a raw material of the component (b), which coexists with the component (b), and the adduct of the alkylene oxide with m in the above formula of 1 or 2 are reduced.

Here, in the present specification, the “narrow ratio” means a ratio represented by the following formula 1 showing a distribution ratio of alkylene oxide adducts having different addition mole numbers of alkylene oxide.

In the formula 1, n _max represents the number of moles of the alkylene oxide added to the alkylene oxide adduct that is most frequently present in the entire alkylene oxide adduct.

  i represents the number of moles of alkylene oxide added.

  Yi represents the ratio (mass%) of the alkylene oxide adduct in which the added mole number of the alkylene oxide present in the entire alkylene oxide adduct is i.

The narrow ratio can be controlled, for example, by a method for producing the component (b).
In the α-sulfofatty acid ester salt-containing liquid of the present invention, as the component (b), only one type may be used alone, or a plurality of types may be used in combination.

In the α-sulfofatty acid ester salt-containing liquid of the present invention, the total content of the α-sulfofatty acid ester salt (a) having 16 to 18 carbon atoms of the fatty acid residue and the fatty acid polyoxyalkylene alkyl ether (b) is as follows: More than 30% by mass and not more than 40% by mass, preferably more than 30% by mass and not more than 37% by mass, more preferably not less than 33% by mass, based on the total mass of the α-sulfofatty acid ester salt-containing liquid, It is 37% by mass or less.

When the total content of the components (a) and (b) is equal to or more than the lower limit, the effects of the present invention are remarkably exhibited. On the other hand, when the total content of the component (a) and the component (b) is equal to or less than the upper limit, the uniformity of the liquid is easily maintained well, and the separation and precipitation hardly occur.
The α-sulfofatty acid ester salt-containing liquid of the present invention may contain impurities inevitable in producing the α-SF salt (a). Examples of the impurities include alkali metal sulfates (such as sodium sulfate), alkali metal alkyl sulfates (such as sodium methyl sulfate), α-sulfofatty acid, and α-sulfofatty acid dialkaline salts (such as α-sulfofatty acid disodium salt). No.
The α-sulfofatty acid ester salt-containing liquid of the present invention may contain, if necessary, an α-SF salt (a), a fatty acid polyoxyalkylene alkyl ether (b), and an inevitable production thereof, as long as the effects of the present invention are not impaired. Other components besides the above impurities may be blended.

  Examples of such other components include an alcohol having 1 to 3 carbon atoms, a pH buffer, a preservative, and a chelating agent.

In the liquid containing the α-sulfofatty acid ester salt of the present invention, the fluidity of the liquid containing the α-sulfofatty acid ester salt is further improved by containing the alcohol having 1 to 3 carbon atoms. Examples of the alcohol having 1 to 3 carbon atoms include monohydric alcohols such as methanol, ethanol, n-propanol, and isopropanol; polyhydric alcohols such as ethylene glycol and propylene glycol. Monohydric alcohols are preferable, and ethanol is more preferable.
The viscosity at 30 ° C. of the α-sulfofatty acid ester salt-containing liquid of the present invention is preferably 0.1 to 10 Pa · s, more preferably 0.5 to 10 Pa · s, and 0.5 to 7.5 Pa · s. More preferred. When it is at least the lower limit of the above range, the viscosity of the composition when blended into the detergent composition is appropriately maintained, and when it is at most the upper limit, the handleability when blending the composition is improved.

The pH at 30 ° C. of the α-sulfofatty acid ester salt-containing liquid of the present invention is preferably from 5.0 to 9.0, more preferably from 5.5 to 8.0. Hydrolysis of α-SF salt (a) and fatty acid polyoxyalkylene alkyl ether (b) in α-sulfofatty acid ester salt-containing solution when the pH of the α-sulfofatty acid ester salt-containing solution is within the above preferred range. Is suppressed, and liquid stabilization can be achieved.

The α-sulfofatty acid ester salt-containing liquid of the present invention can be produced by mixing the above components (a) and (b) with water. For example, it can be produced by adjusting the pH to a predetermined value while dissolving the component (a), the component (b) and, if necessary, an optional component in water as a solvent. As the component (a), for example, any of a paste or a solid after neutralization or bleaching can be used.

Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples. In this example, “%” indicates “% by mass” unless otherwise specified.
The raw materials shown in Table 1 were used.

The component (a), α-sulfofatty acid methyl ester sodium salt (α-SF-Na), is mixed with a flaky solid of α-sulfofatty acid methyl ester sodium salt (hereinafter referred to as “α-SF salt solid”). Object). The α-SF salt solid was prepared by producing a paste-like concentrate of α-SF salt as described below, and cooling and pulverizing it.
(Production Example 1) Production of Paste α-SF-Na Salt (a1) In this example, methyl palmitate (Pastel M-16 manufactured by Lion Corporation) and stearic acid were used as fatty acid esters as raw materials. A fatty acid methyl ester mixture was used which was previously mixed with methyl (trade name: Pastel M-180 manufactured by Lion Corporation) in a mass ratio of 85:15.

330 kg of the fatty acid methyl ester mixture is injected into a 1-kL reactor equipped with a stirrer, and while stirring, the reaction temperature is maintained at 80 ° C., and SO ₃ gas (sulfonated gas) 115 diluted to 8% by volume with nitrogen gas is used. 1.6 kg (1.2 times the mol of the fatty acid methyl ester mixture) was blown at a constant speed over 4 hours while bubbling. Thereafter, 0.25 parts by mass of anhydrous sodium sulfate was added to 100 parts by mass of the fatty acid methyl ester mixture, and aging was performed for 30 minutes while maintaining at 80 ° C. Thereafter, 13.5 kg of methanol was supplied as a lower alcohol, and the esterification was carried out at a temperature of 80 ° C. and an aging time of 75 minutes. Next, the esterified product extracted from the reactor was continuously neutralized by adding an equivalent amount of an aqueous sodium hydroxide solution using a line mixer.

  Then, the neutralized product is injected into a bleach mixing line, and 35% by volume of hydrogen peroxide solution is supplied and mixed at a purity of 1% by mass with respect to the AI content. Was performed to obtain an α-SF-Na salt (a1).

The molecular weight of the α-SF-Na salt contained in the obtained α-SF-Na salt (a1) was calculated from the carbon chain length ratio (mass ratio) of the charged raw material, and was set to 377.
(Production Example 2) Production of Paste α-SF-Na Salt (a2) In this example, methyl palmitate (same as in Production Example 1) and methyl stearate (as in Production Example 1) were used as fatty acid esters as raw materials. The same) and a fatty acid methyl ester mixture previously mixed so as to have a mass ratio of 6: 4.

330 kg of the fatty acid methyl ester mixture was injected into a 1-kL reactor equipped with a stirrer, and 112.8 kg of SO ₃ gas (sulfonated gas) diluted to 8% by volume with nitrogen gas at a reaction temperature of 80 ° C. while stirring was added. (1.2 times mol with respect to the fatty acid methyl ester mixture) was blown at a constant speed over 4 hours while bubbling. Thereafter, 0.25 parts by mass of anhydrous sodium sulfate was added to 100 parts by mass of the fatty acid methyl ester mixture, and aging was performed for 30 minutes while maintaining at 80 ° C.

  Thereafter, an α-SF-Na salt (a2) was obtained in the same manner as in the production of the α-SF-Na salt (a1).

The molecular weight of the α-SF-Na salt contained in the obtained α-SF-Na salt (a2) was calculated from the carbon chain length ratio (mass ratio) of the charged raw material, and was set to 384.

Concentration of α-SF-Na salt in paste form:
Each of the obtained paste-like α-SF-Na salts (a1) and (a2) is rotated at a rotation speed of 1060 rpm and a blade tip speed of about 11 m / s (heat transfer surface: 0.5 m ^2. The inner diameter of the cylindrical processing section: 205 mm, the clearance between the heat transfer surface and the blade tip as a scraping means: 3 mm, trade name “Exeva”, manufactured by Shinko Pantech Co., Ltd.) at 35 kg / hr, Concentration was performed under the conditions of an inner wall heating temperature (temperature of the heat transfer surface) of 135 ° C. and a degree of vacuum (pressure in the processing section) of 0.007 to 0.014 MPa. The temperature of the obtained concentrate was 115 ° C., and the water content was 2.5% by mass.
Production of α-SF salt solids:
Each of the obtained concentrates was continuously supplied at 222 kg / h to a double belt type belt cooler (NR3-Lo. Cooler) manufactured by Nippon Belting Co., Ltd. in which the clearance between the input pulleys was adjusted to 2 mm and cooled. At this time, the belt moving speed was set at 6 m / s, and the flow rate of the cooling water was 1500 L / h on the upper belt side (cooled down on the back side of the belt in a countercurrent manner) and 1800 L / h on the lower belt side (back side of the belt). And cooled by cooling to a temperature of 20 ° C. Next, the α-SF salt-containing sheet obtained by discharging from the cooling belt was crushed at a rotation speed of 200 rpm by an attached crusher installed near a discharge pulley, thereby forming a flake-like sheet at 25 ° C. α-SF salt solids (a1) and (a2) were obtained.

Anionic surfactant concentration in solid α-SF salt (total concentration (AI) of α-sulfofatty acid methyl ester sodium salt (α-SF-Na) and α-sulfofatty acid disodium salt (di-Na salt) ) Was measured as follows. <Method of measuring AI>
The content of the total (AI) of α-sulfofatty acid methyl ester sodium salt (α-SF-Na) and α-sulfofatty acid disodium salt (di-Na salt) was measured as follows.

  A sample having an amount of about 0.16 g as an AI pure component was accurately weighed into a 200 mL volumetric flask, ion-exchanged water (distilled water) was added up to the marked line, and the sample was dissolved in ion-exchanged water by ultrasonic waves. . After dissolution, the solution was cooled to about 25 ° C., 5 mL of the sample aqueous solution was taken into a titration bottle with a whole pipette, 25 mL of methylene blue indicator and 15 mL of chloroform were added, and 5 mL of a 0.004 mol / L benzethonium chloride solution was further added. Titration was performed with a 0.002 mol / L sodium alkylbenzene sulfonate solution. In each titration, the titration bottle was stoppered and vigorously shaken, then allowed to stand, and the point at which both layers separated against the white plate as a background had the same color tone was regarded as the end point.

  Similarly, a blank test (the same test as described above except that no sample is used) was performed, and the content of AI in the α-SF salt solid was calculated from the following formula based on the difference in titer of the sodium alkylbenzene sulfonate solution. did.

AI content (% by mass) = (titration in blank test (mL) −titration (mL)) × 0.002 (mol / L) × molecular weight of α-sulfofatty acid methyl ester salt / (sample collection amount ( g) × 5 (mL) / 200 (mL)) / 10

As a result of the above measurement, the concentration of the anionic surfactant in the α-SF salt solid (a1) was 90.0% by mass, and the concentration of the anionic surfactant in the α-SF salt solid (a2) was 88.1% by mass. Met. <Method for measuring content of α-sulfofatty acid disodium salt>
The content of α-sulfofatty acid disodium salt in the α-SF salt solid was measured as follows.

  0.02 g, 0.05 g, and 0.1 g of α-sulfofatty acid disodium salt standard products were each accurately weighed into a 200 mL volumetric flask, and dissolved by adding about 50 mL of water and about 50 mL of ethanol. After dissolution, the mixture was cooled to about 25 ° C., and methanol was accurately added to the marked line, and this was used as a standard solution. After filtering about 2 mL of this standard solution using a 0.45 μm chromato disk, analysis was performed by high performance liquid chromatography under the following measurement conditions, and a calibration curve was created from the peak area.

[Measurement conditions for high performance liquid chromatography analysis]
-Equipment: LC-6A (manufactured by Shimadzu Corporation)
・ Column: Nucleosil 5SB (GL Science)
-Column temperature: 40 ° C
・ Detector: Differential refractive index detector RID-6A (manufactured by Shimadzu Corporation)
Mobile phase: 0.7% sodium perchlorate in H ₂ O / CH ₃ OH = 1/4 (volume ratio) solution Flow rate: 1.0 mL / min.
・ Injection volume: 100 μL
Next, 1.5 g of solid α-SF salt as an AI pure component was accurately measured in a 200 mL volumetric flask, and dissolved by adding about 50 mL of water and about 50 mL of ethanol. After dissolution, the mixture was cooled to about 25 ° C., and methanol was accurately added to the marked line, and this was used as a test solution. Approximately 2 mL of the test solution was filtered using a 0.45 μm chromatodisk, and then analyzed by high performance liquid chromatography under the same measurement conditions as described above, and the α-sulfofatty acid disodium salt in the sample solution was analyzed using the calibration curve. The concentration was determined.

As a result of the measurement, the di-Na salt concentration in the α-SF salt solid (a1) was 4.2% by mass, and the di-Na salt concentration in the α-SF salt solid (a2) was 3.6% by mass. Met.

From the above, the α-sulfofatty acid methyl ester sodium salt (α-SF-Na) in the α-SF salt solid (a1) is 85.8% by mass, and the α-sulfo fatty acid methyl solid in the α-SF salt solid (a2) is Fatty acid methyl ester sodium salt (α-SF-Na) was calculated to be 84.5% by mass, and in this example, these values were used for the content of the component (a).
The fatty acid polyoxyalkylene alkyl ether used in this example was synthesized according to the production example in Examples described in JP-A-2000-144179.

(Production Example 3) Fatty acid polyoxyethylene methyl ether (m = average 15, narrow ratio 33 mass%) (b1) The production chemical composition is 2.5 MgO.Al 2 O 3 .nH 2 O.Alumina hydroxide / magnesium hydroxide (Kyowa Chemical Industry Co., Ltd. And 2.2 g of a calcined alumina-magnesium hydroxide (unmodified) catalyst obtained by calcining a product (trade name: Kyoward 300) at 600 ° C. for 1 hour in a nitrogen atmosphere, and 0.5 N. 2.9 mL of a potassium hydroxide ethanol solution, 262.5 g of lauric acid methyl ester and 87.5 g of myristic acid methyl ester were charged into a 4-liter autoclave, and the catalyst was reformed in the autoclave. Next, after the inside of the autoclave was replaced with nitrogen, the temperature was raised, and while maintaining the temperature at 180 ° C. and the pressure at 3 atm, 1048 g of ethylene oxide was introduced and reacted while stirring. Further, the reaction solution was cooled to 80 ° C., and after adding 159 g of water and 5 g of activated clay and diatomaceous earth each as a filter aid, the catalyst was separated by filtration to obtain (b1). The amount of alkali added to the catalyst was adjusted so that the narrow ratio of (b) was 33% by mass.

(Production Example 4) Production of fatty acid polyoxyethylene methyl ether (m = 11 on average, narrow ratio: 33% by mass) (b2) The same procedure as in Production Example 3 was carried out except that the amount of ethylene oxide was changed to 768 g. I got something.

(Production Example 5) As a raw material for producing fatty acid polyoxyethylene methyl ether (m = average 15, narrow ratio 33 mass%) (b3), carbon number derived from palm oil containing methyl oleate or methyl linoleate as a main component The target product was prepared in the same manner as in Production Example 3 except that a fatty acid methyl ester mixture (trade name: Pastel M182, manufactured by Lion Corporation) derived from fraction 18 was used, and the amount of ethylene oxide was changed to 780 g. Obtained.
<Method for measuring the number of moles of ethylene oxide added to fatty acid polyoxyalkylene alkyl ether>
The distribution of ethylene oxide adducts having different addition mole numbers of ethylene oxide was measured under the following measurement conditions, and the narrow ratio (% by mass) was calculated by the above equation (1).
[Conditions for measuring distribution of ethylene oxide adduct by HPLC]
Apparatus: LC-6A (manufactured by Shimadzu Corporation),
Detector: SPD-10A,
Measurement wavelength: 220 nm,
Column: Zorbax C8 (manufactured by Du Pont),
Mobile phase: acetonitrile / water = 60/40 (volume ratio),
Flow rate: 1 mL / min,
Temperature: 20 ° C

(Examples 1 to 14, Comparative Examples 1 to 5)
According to the compositions shown in Tables 2 to 4, the components (a) and (b) were added to water and mixed, stirred at 70 ° C. until the mixture became uniformly transparent, and then allowed to cool. To 5 were obtained. In addition, an α-sulfofatty acid ester salt-containing liquid of Comparative Example 1 was obtained in the same manner as described above except that the component (b) was not added.
In the table, the contents of the blending components are shown in terms of pure components.
"Balance" indicating the content of purified water means the balance added so that the total amount (% by mass) of all the components contained in the liquid detergent becomes 100% by mass.

  The pH (30 ° C.) of the obtained α-sulfofatty acid ester salt-containing solution was in the range of 5.5 to 7.5 in all examples.

The α-sulfofatty acid ester salt-containing liquid of each example was evaluated for appearance and measured for viscosity at 30 ° C. by the following methods. The evaluation results are shown in Tables 2 to 4.
<Appearance evaluation method>
In preparing the α-sulfofatty acid ester salt-containing solution, the solution was stirred at 70 ° C. until the solution became uniformly transparent, and then left standing in an atmosphere at 30 ° C. for one day, followed by visual observation. Evaluation was made according to the following criteria. The state in which the separation occurred was observed in a state in which a large number of small spheres were slightly suspended in the solution, or in a state in which some large transparent lumps were suspended.

  〇: Uniform and transparent.

  Δ: Separation occurred.

×: Precipitation occurred.
<Method of measuring viscosity>
The sample was adjusted to 30 ° C. and measured using a B-type viscometer (manufactured by TOKIMEC). The measurement conditions are shown below. In addition, the thing whose evaluation result of external appearance was x and (DELTA) did not measure a viscosity (it showed "-" in the table | surface that the viscosity was not measured).

  Measurement conditions: The rotational speed was 30 rpm, and the viscosity after 30 seconds was measured.

  When the viscosity is in the range of 0.1 to 5 Pa · s, the rotor no. Use 3

  When the viscosity is 0.1 Pa · s or less, the rotor no. Use 1 or 2.

  When the viscosity is 5 Pa · s or more, the rotor no. Use 4.

  As shown in the results of Tables 2 to 4, Comparative Examples 3, 5, and (a) in which the total content of the α-SF salt (a) and the fatty acid polyoxyethylene methyl ether (b) exceeds 40% by mass. Comparative Example 4 having a large mass ratio of (b) was separated when stored at 30 ° C.

  In particular, when comparing Example 5 and Comparative Example 3, the mass ratio of (a) / (b) is the same, and only the total content of the components (a) and (b) is increased by only 2% by mass. The evaluation of the appearance decreased from △ to △.

  In Comparative Example 1 not containing the fatty acid polyoxyethylene methyl ether (b) and Comparative Example 2 in which the total content of the components (a) and (b) was 45% by mass, precipitation occurred when allowed to stand still. Was.

  Comparing Examples 1 to 4 and 8 to 11, when the total content of the component (a) and the component (b) is the same, the lower the mass ratio (a) / (b), the lower the viscosity. Was.

Claims (1)

And it expresses the following general formula (I) alpha-sulfo fatty acid ester salt (a), the fatty acid polyoxyalkylene alkyl ether represented by the following general formula (II) (b), contains water,
The total content of (a) and (b) is more than 30% by mass and 40% by mass or less, and the mass ratio of (a) / (b) is 1.5 or more and 9.0 or less. Α-sulfofatty acid ester salt-containing liquid.
[In the formula (I), R ¹ is a hydrocarbon group having 14 to 16 carbon atoms, R ² is a hydrocarbon group having 1 carbon atom, and M is a sodium ion. ]
R ³ —CO (OR ⁴ ) mOR ⁵ (II)
[In the formula (II), R ³ is a saturated or unsaturated hydrocarbon group having 9 to 18 carbon atoms, R ⁴ is a hydrocarbon group having 2 to ⁴ carbon atoms, and R ⁵ is a hydrocarbon group having 1 to 3 carbon atoms. M is an average number of moles of alkylene oxide added, and is 5 to 25. ]