Detergent composition

Abstract

The present invention provides a detergent composition in which thermal deterioration is suppressed. The detergent composition of the present invention is a liquid detergent composition comprising (a) a fatty acid salt and (b) a sophorolipid, in which the fatty acid salt (a) comprises (a-1) at least one member selected from the group consisting of salts of C14-C22 saturated fatty acids and (a-2) at least one member selected from the group consisting of salts of C14-C22 unsaturated fatty acids, and the components are contained in the following proportions: A) based on 100 mass% of the detergent composition, the total amount of the component (a) is 2-35 mass%; b) the proportion of component (a-2) is 20 parts by mass or more based on 100 parts by mass of the total amount of component (a); and C) the proportion of component (b) is 3 parts by mass or more per 100 parts by mass of component (a-2).

Description

Technical Field

[0001] The present invention relates to a detergent composition. More specifically, the present invention relates to a detergent composition comprising a saturated fatty acid salt and an unsaturated fatty acid salt as a fatty acid salt, wherein the advantages of each fatty acid salt are utilized while improving their disadvantages. The present invention also relates to a method for improving the disadvantages of a detergent composition comprising an unsaturated fatty acid salt as a fatty acid salt. Background Art

[0002] Cleansers are used to clean the body including hands, face and head as well as hair, dishes, houses, clothes and anything in daily life. Cleansers have the effect of removing stains, removing bacteria to prevent infection, and / or removing and suppressing odors, as well as the effect of refreshing the user by cleaning. Such cleansers need to be stable against light and heat, have less irritation to the skin, ensure good foaming and good foam quality, and / or impart an excellent feeling during use (e.g., no unpleasant slippery feeling during rinsing and / or no squeaking feeling or skin tightness after cleaning).

[0003] In particular, it is known that the slippery feeling during rinsing and the squeaky feeling and skin tightness after washing are caused by the synthetic surfactant or fatty acid salt (soap-based material) contained in the detergent as a cleaning and foaming component remaining on the skin. Several methods have been proposed to solve these problems. For example, it is reported that problems such as the slippery feeling during rinsing or after washing, the squeaky feeling, and the skin tightness can be solved by incorporating a sophorolipid (which may be referred to as "SL" hereinafter), which is a natural surfactant, into the detergent to inhibit the synthetic surfactant or fatty acid salt from adhering to and remaining on the human body (see, for example, Patent Document 1).

[0004] SL (non-patent document 1), which is a glycolipid biosurfactant (natural surfactant) type produced by microorganisms, has less irritation to the skin, has high biodegradability, and is good to the natural environment. In this sense, SL has the same characteristics as alkaline soap (fatty acid salt), which is a detergent with a high level of safety and biodegradability. Therefore, the applicant has previously found that adding SL to a soap-based material (fatty acid salt) improves the disadvantages of soap (such as low solubility in water and poor foaming under hard water conditions) while utilizing the advantages of soap (high level of safety and biodegradability), and further improves the moisturizing properties, and the applicant has proposed a detergent composition comprising a soap-based material (fatty acid salt) and SL (see, for example, patent document 2). The applicant has also proposed such a detergent composition: its combination comprises a soap-based material (fatty acid salt) and SL to prevent clogging at the distribution outlet when stored and used in a dispenser, while improving stability at low temperatures (see patent document 3).

[0005] Reference List

[0006] Patent Literature

[0007] Patent Document 1: JP2009-275145

[0008] Patent Document 2: JP2006-083238

[0009] Patent Document 3: WO2018 / 164204

[0010] Non-patent literature

[0011] Non-patent document 1: Canadian Journal of Chemistry, 39, 846 (1961) Summary of the invention

[0012] Technical issues

[0013] As described above, by incorporating fatty acid salts (which are soap-based materials) and SL into a cleanser, it is possible to improve the disadvantages of soap (such as low solubility in water and poor foaming under hard water conditions) while utilizing the advantages of soap (high level of safety and biodegradability), and in addition, the feeling of skin tightness and crunching after washing can be suppressed.

[0014] However, according to the findings of the present inventors, C 12The alkali metal salt of saturated fatty acid (lauric acid) (which is the lauric acid soap in the soap base material) has the problem of high stimulation to the skin. In contrast, myristic acid soap, palmitic acid soap and stearic acid soap etc. (which are the alkali metal salts of saturated fatty acids with 14 or more carbon atoms in the soap base material) are less irritating to the skin (see Experimental Example 1), but the problem is that a large amount of insoluble metal soaps are formed during rinsing, which leaves a strong creaking feeling or skin tightness after cleaning, and causes the skin to dry out. These problems about saturated fatty acid salts can be solved by adding the salt of the unsaturated fatty acid with unsaturated bonds in addition to the saturated fatty acid salts. However, unsaturated fatty acids, especially linoleic acid, are easily deteriorated by heat, which causes coloration and odor generation over time.

[0015] The main object of the present invention is to inhibit the deterioration of unsaturated fatty acid salts due to heat over time in a detergent composition comprising fatty acid salts (particularly unsaturated fatty acid salts) and SL. "Deterioration" as used herein refers to a phenomenon caused by the decomposition of unsaturated fatty acid salts due to heat, and specifically includes at least one of the following phenomena: formation of low molecular weight compounds caused by the decomposition of unsaturated fatty acids, coloration, and odor generation.

[0016] Another object of the present invention is to reduce skin irritation during use of a cleansing composition comprising a fatty acid salt (especially an unsaturated fatty acid salt) and SL.

[0017] Another object of the present invention is to suppress the amount of metal soap generated from hard water components in tap water during rinsing in a detergent composition comprising fatty acid salts (especially unsaturated fatty acid salts) and SL to improve the crunchy feeling during rinsing and the skin tight feeling after rinsing.

[0018] Technical Solution

[0019] The present inventors conducted extensive studies and found that the above problems can be solved by preparing a detergent composition containing a specific saturated fatty acid salt and a specific unsaturated fatty acid salt as fatty acid salts and SL in a specific ratio.

[0020] The present invention has been completed as a result of further studies based on this finding, and encompasses the following embodiments.

[0021] (I) Cleaning agent composition

[0022] (I-1) A liquid detergent composition comprising:

[0023] (a) fatty acid salts; and

[0024] (b) SL,

[0025] in

[0026] The fatty acid salt (a) comprises (a-1) selected from C 14 -C 22 At least one member of the salt of a saturated fatty acid and (a-2) is selected from C 14 -C 22 at least one member of the salts of unsaturated fatty acids, and

[0027] The components are included in the following proportions:

[0028] A) the total amount of component (a) is 2% to 35% by mass based on the detergent composition regarded as 100% by mass;

[0029] B) the proportion of component (a-2) is 20 parts by mass or more based on 100 parts by mass of the total amount of component (a); and

[0030] C) The proportion of the component (b) is 3 parts by mass or more per 100 parts by mass of the component (a-2).

[0031] (I-2) The detergent composition according to (I-1), wherein B) the proportion of component (a-2) is 20 to 95 parts by mass based on 100 parts by mass of the total amount of component (a).

[0032] (I-3) The detergent composition according to (I-1) or (I-2), wherein the proportion of C) component (b) is 3 parts by mass to 500 parts by mass per 100 parts by mass of component (a-2).

[0033] (I-4) The detergent composition according to any one of (I-1) to (I-3), wherein A) the total amount of component (a) is 3% by mass to 32% by mass based on the detergent composition regarded as 100% by mass.

[0034] (I-5) The cleaning composition according to any one of (I-1) to (I-4),

[0035] in

[0036] Component (a-1) is a salt of at least one member selected from the group consisting of myristic acid, palmitic acid, isopalmitic acid, stearic acid, isostearic acid and arachidic acid, and

[0037] Component (a-2) is a salt of at least one member selected from the group consisting of oleic acid, linoleic acid, linolenic acid, palmitoleic acid, arachidonic acid, eicosenoic acid, erucic acid, eicosadienoic acid, docosadienoic acid and mead acid.

[0038] (II) Method for suppressing thermal degradation of detergent composition

[0039] (II-1) A method for inhibiting thermal degradation of a detergent composition comprising (a) a fatty acid salt, wherein the fatty acid salt (a) comprises (a-1) selected from C 14 -C 22 At least one member of the salt of a saturated fatty acid and (a-2) is selected from C 14 -C 22 at least one member of a salt of an unsaturated fatty acid, the method comprising incorporating (b) SL in an amount of 3 mass % or more per 100 mass parts of component (a-2) in the detergent composition.

[0040] (II-2) The method according to (II-1), wherein the detergent composition contains at least a salt of at least one unsaturated fatty acid selected from linoleic acid, linolenic acid, eicosadienoic acid, docosadienoic acid, mead acid and arachidonic acid as component (a-2).

[0041] (II-3) The method according to (II-1) or (II-2), wherein the detergent composition comprises component (a) and component (a-2) in the following ratio:

[0042] A) the total amount of component (a) is 2% to 35% by mass based on the detergent composition regarded as 100% by mass; and

[0043] B) The proportion of the component (a-2) is 20 parts by mass or more based on 100 parts by mass of the total amount of the component (a).

[0044] (II-4) The method according to (II-3), wherein A) the total amount of component (a) is 3% by mass to 32% by mass based on the detergent composition regarded as 100% by mass.

[0045] (II-5) The method according to (II-3), wherein B) the proportion of component (a-2) is 20 parts by mass to 95 parts by mass based on 100 parts by mass of the total amount of component (a).

[0046] (II-6) The method according to any one of (II-1) to (II-5), wherein the proportion of component (b) is 3 parts by mass to 500 parts by mass per 100 parts by mass of component (a-2).

[0047] Beneficial Effects

[0048] According to the present invention, a detergent composition in which the deterioration of the unsaturated fatty acid salt due to heat is suppressed can be provided by containing a specific saturated fatty acid salt and a specific unsaturated fatty acid salt as fatty acid salts and SL in a specific ratio. More specifically, the present invention can provide a detergent composition with good thermal stability: in the detergent composition, the formation of low molecular weight compounds caused by the decomposition of linoleate in particular in the unsaturated fatty acid salt, coloration and / or odor generation is suppressed.

[0049] The present invention also provides a method for inhibiting the deterioration due to heat in a detergent composition, wherein the detergent composition particularly comprises linoleate as an unsaturated fatty acid salt. More specifically, the present invention provides a method for inhibiting the formation, coloration and / or odor generation of low molecular weight compounds in a detergent composition comprising an unsaturated fatty acid salt.

[0050] According to the present invention, a detergent composition having at least one of the following effects in addition to the above effects can be provided by containing a specific saturated fatty acid salt and a specific unsaturated fatty acid salt as fatty acid salts and SL at a specific ratio:

[0051] (i) inhibiting the formation of metal soaps;

[0052] (ii) low skin irritation; and

[0053] (iii) Good stability at low temperatures.

[0054] The detergent composition of the present invention having at least one of the above-mentioned effects (i) to (iii) and / or the above-mentioned thermal degradation inhibition effect can be used daily for washing the human body (e.g., hair and body, including hands, face and head), body (including body hair of pets such as dogs and cats), as well as dishes, houses, clothes and anything in daily life. In particular, the detergent composition of the present invention having the above-mentioned thermal degradation inhibition effect and the above-mentioned effect (ii) can be used as a detergent composition that can be particularly suitable for use on the body or hair of infants and / or people with sensitive skin. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1-1 The HPLC chromatogram of the sample of the detergent composition of Example 1 before storage at 50° C. is shown (see Experimental Example 1 (2)).

[0056] Figure 1-2 The HPLC chromatogram of a sample of the detergent composition of Example 1 after storage at 50° C. is shown (see Experimental Example 1 (2)).

[0057] Figure 2-1The HPLC chromatogram of the sample of the detergent composition of Comparative Example 1 before storage at 50° C. is shown (see Experimental Example 1 (2)).

[0058] Figure 2-2 The HPLC chromatogram of a sample of the detergent composition of Comparative Example 1 after storage at 50° C. is shown (see Experimental Example 1 (2)).

[0059] Figure 3 It is a graph showing comparison of cell viability (%) in the skin irritation test results of various fatty acid salts (C12K: potassium laurate, C14K: potassium myristic acid, C16K: potassium palmitate, C18-1K: potassium oleate) in Experimental Example 3. DETAILED DESCRIPTION

[0060] (I) Cleaning agent composition

[0061] The detergent composition of the present invention comprises (a) a fatty acid salt and (b) SL as active ingredients. Components (a) and (b) are described below.

[0062] (a) Fatty acid salts

[0063] Component (a) of the detergent composition of the present invention consists of a fatty acid and an alkali.

[0064] Component (a) comprises (a-1) selected from C 14 -C 22 At least one member of the salt of a saturated fatty acid and (a-2) is selected from C 14 -C 22 A combination of at least one member selected from the group consisting of salts of unsaturated fatty acids. 14 -C 22 At least one member (a-1) of the salt of a saturated fatty acid is referred to as "component (a-1)", and selected from C 14 -C 22 At least one member (a-2) of the salt of unsaturated fatty acid is referred to as "component (a-2)".

[0065] Fatty acid salts having 12 or fewer carbon atoms are more irritating to the skin than fatty acid salts having 14 or more carbon atoms and are therefore unsuitable as component (a) contained in the detergent composition of the present invention. Therefore, it is preferred that the detergent composition of the present invention does not contain fatty acid salts having 12 or fewer carbon atoms.

[0066] Component (a-1) comprises myristic acid (C14), pentadecanoic acid (C15), palmitic acid (C16), isopalmitic acid (C16), margaric acid (C17), stearic acid (C18), isostearic acid (C18), arachidic acid (C20) and behenic acid (C22) (all of which are C 14 -C 22 Saturated fatty acids). Preferably C 14 -C 18 Salts of saturated fatty acids. Component (a-1) is more preferably a salt of at least one saturated fatty acid selected from myristic acid, palmitic acid, isopalmitic acid, stearic acid and isostearic acid. These saturated fatty acid salts may be used alone or in any combination of two or more.

[0067] Component (a-2) comprises myristic acid (C14:1), palmitic acid (C16:1), oleic acid (C18:1), elaidic acid (C18:1), eicosenoic acid (C20:1), erucic acid (C22:1) (all monounsaturated fatty acids), linoleic acid (C18:2), eicosadienoic acid (C20:2), docosadienoic acid (C22:2) (all diunsaturated fatty acids), linolenic acid (C18:3), mead acid (C20:3) (all triunsaturated fatty acids), and arachidonic acid (C20:4) (tetraunsaturated fatty acids) (all C 14 -C 22 unsaturated fatty acid). Preferably C 18 -C 20 Component (a-2) is more preferably at least one selected from oleic acid, linoleic acid and linolenic acid. 18 Salts of unsaturated fatty acids. These unsaturated fatty acid salts may be used alone or in any combination of two or more.

[0068] As shown in Experimental Example 1, in particular, in component (a-2), diunsaturated fatty acid salts, triunsaturated fatty acid salts and tetraunsaturated fatty acid salts (all of which have two or more double bonds) tend to be easily decomposed by heat. Examples of unsaturated fatty acid salts that are particularly easy to decompose by heat include linoleate, linolenate, eicosadienoate, docosadienoate, meadate and arachidonate. Therefore, the detergent composition comprising at least one of these as component (a-2) greatly benefits from the deterioration inhibition effect of the present invention.

[0069] The fatty acids constituting components (a-1) and (a-2) may be of natural or synthetic origin and may be of plant or animal origin. The fatty acids constituting components (a-1) and (a-2) are preferably fatty acids derived from natural vegetable oils and fats.

[0070] Examples of natural oils and fats include vegetable oils and fats, such as linseed oil, perilla oil, oiticica oil, olive oil, cocoa butter, kapok oil, white mustard oil, sesame oil, rice bran oil, safflower oil, shea butter, china wood oil, soybean oil, tea seed oil, camellia oil, corn oil, rapeseed oil, palm oil, palm kernel oil, castor oil, sunflower oil, cottonseed oil, coconut oil, Japan wax and peanut oil; and animal oils and fats, such as horse tallow, beef tallow, lard, mutton tallow, milk fat, fish fat and whale fat.

[0071] Examples of counterions that react with the above-mentioned saturated fatty acids or unsaturated fatty acids to form fatty acid salts include those used as counterions in fatty acid soaps. Examples of bases or basic compounds used as counterions include alkali metals such as lithium, sodium and potassium; alkanolamines such as triethanolamine, diethanolamine, aminomethylpropanol and tromethamine; basic amino acids such as arginine and lysine; ammonium; and the like. Alkali metals such as sodium and potassium and alkanolamines such as diethanolamine and triethanolamine are preferred. Alkali metals such as sodium and potassium are more preferred, and potassium is particularly preferred.

[0072] The total amount of component (a) contained in the detergent composition of the present invention is 2% to 35% by mass. If the content of component (a) is significantly less than 2% by mass, foaming tends to be poor. The lower limit of component (a) is 2% by mass or more, preferably 3% by mass or more, more preferably 3.5% by mass or more, and even more preferably 5% by mass or more.

[0073] If the content of component (a) is significantly greater than 35 mass %, the fluidity of the composition is poor, which makes it difficult to maintain liquid properties. The upper limit of component (a) is 35 mass % or less, preferably 30 mass % or less, more preferably 25 mass % or less, and even more preferably 20 mass % or less. Any combination of these lower and upper limits can be selected. The content of component (a) in the range of, for example, 3 mass % to 35 mass %, 3 mass % to 30 mass %, 3.5 mass % to 30 mass %, 3.5 mass % to 25 mass % or 5 mass % to 20 mass % can be selected.

[0074] The proportion of the component (a-2) is 20 parts by mass or more based on 100 parts by mass of the component (a) contained in the detergent composition of the present invention.

[0075] If the proportion of component (a-2) is less than 20 parts by mass, when the resulting detergent composition is diluted or rinsed with tap water, the fatty acid in the detergent composition tends to combine with the divalent metal ions in the tap water containing divalent metal ions, thereby forming a large amount of water-insoluble metal soaps (fatty acid calcium salts, fatty acid magnesium salts). Metal soaps tend to adhere to and remain on the object being cleaned. Therefore, when such a detergent composition is applied to the human body (body, hair), it causes unpleasant sensations, such as a creaking sensation and a tight feeling of the skin after cleaning, and also has adverse effects, such as a reduction in skin moisture. When such a detergent composition is used to clean houses, clothes, etc., it causes white residues. In contrast, by adjusting the proportion of component (a-2) to 20 parts by mass or more based on 100 parts by mass of component (a), even when the detergent composition is diluted or rinsed with tap water, the formation of metal soaps can be suppressed, and the above-mentioned sensation during use and the problems of white residues can be reduced.

[0076] The tap water mentioned above is water having a hardness of usually 300 mg / l or less (according to ministerial regulations related to water quality standards of the Japanese Water Supply Act), typically about 10 mg / l to 100 mg / l.

[0077] Water hardness can be determined using the following formula.

[0078] Hardness (mg / l) = (calcium content (mg / l) × 2.5) + (magnesium content (mg / l) × 4)

[0079] Based on 100 mass parts of components (a), the lower limit of the ratio of component (a-2) is 20 mass parts or more, preferably 40 mass parts or more, and more preferably 50 mass parts or more. The upper limit of the ratio of component (a-2) is not limited, as long as it is less than 100 mass parts. For example, the upper limit of the ratio of component (a-2) is 98 mass parts or less, preferably 95 mass parts or less, and more preferably 93 mass parts or less. Any combination of these lower limits and upper limits can be selected. The ratio of component (a-2) in the range of, for example, 20 mass parts to less than 100 mass parts, 20 mass parts to 98 mass parts, 40 mass parts to 98 mass parts or 50 mass parts to 95 mass parts can be selected.

[0080] (b) Sophorolipids (SL)

[0081] Component (b) used in the detergent composition of the present invention is a glycolipid composed of a hydroxy fatty acid and sophorose or a sophorose in which one or more hydroxyl groups are acetylated. Sophorose is a sugar composed of two glucose molecules bonded by a β1→2 bond. A hydroxy fatty acid is a fatty acid having a hydroxyl group.

[0082] SL is roughly divided into acid-type SL represented by the following formula (1) and lactone-type SL represented by the following formula (2). Acid-type SL is a sophorolipid in which the carboxyl group of the hydroxy fatty acid is free. Lactone-type SL is a sophorolipid in which the carboxyl group of the hydroxy fatty acid is bonded to sophorose in the molecule.

[0083]

[0084] In the above chemical formula, R 0 is a hydrogen atom or a methyl group. 1 and R 2 Each is independently a hydrogen atom or an acetyl group. 3 It is composed of a saturated aliphatic hydrocarbon chain or an unsaturated aliphatic hydrocarbon chain having at least one double bond. The aliphatic hydrocarbon chain generally has 11 to 20 carbon atoms, preferably 13 to 17 carbon atoms, and more preferably 14 to 16 carbon atoms. The SL mentioned herein includes salts of the acid-type SL represented by the above formula (1). Examples of the salt include salts of alkali metals such as potassium and sodium, salts of alkaline earth metals such as magnesium and calcium, and ammonium salts. Alkali metal salts are preferred, and potassium salts and sodium salts are more preferred.

[0085] As used herein, the term "sophorolipid (SL)" does not distinguish between lactone-type SL, acid-type SL, and salts thereof. In this case, the sophorolipid (SL) may be a lactone-type SL, an acid-type SL, or a salt of an acid-type SL, or may include a mixture of two or more of these. When the term "sophorolipid (SL)" refers to any of them, it is referred to as an "acid-type SL" or a "lactone-type SL". Unless otherwise specified, the term "acid-type SL" includes both an acid-type SL in free form and an acid-type SL in salt form. Acid-type SL and lactone-type SL may each be a lactone-type SL, an acid-type SL, or a salt of an acid-type SL. 0 To R 3 Each is a single compound of a specific atom or substituent in the above formula, or may be a compound having different R 0 To R 3 A mixture (composition) of multiple compounds.

[0086] Specifically, SL is obtained by culturing microorganisms, especially yeast. SL obtained by yeast fermentation includes both the above-mentioned acid-type SL and lactone-type SL.

[0087] Examples of yeasts that produce SL include Starmerella (Candida) bombicola, C. apicola, C. petrofilum, Rhodotorula (Candida) bogoriensis, and the like. By culturing such yeasts using a medium containing a high concentration of sugar and an oily substrate, a large amount (100 g / L to 150 g / L) of SL can be produced and accumulated in the medium. SL can be isolated by subjecting the culture to a purification treatment such as centrifugation, decantation, or ethyl acetate extraction, and can be obtained as a dark brown candy-like substance by further washing the SL with hexane. Since SLs have a greater specific gravity than water, they can be easily removed in such a manner that the culture is allowed to stand after the completion of the culture, thereby separating the SL by settling into the lower layer. The SL thus obtained is an SL having a water content of about 50% by mass. The obtained SL is a mixture of a plurality of compounds represented by the above formulae (1) and (2). These SLs include acid-type SLs and lactone-type SLs.

[0088] In the present invention, component (b) may be an acidic SL, a lactone SL, or a mixture thereof. From the viewpoint of product stability (e.g., pH stability and suppression of appearance changes associated with pH changes (e.g., precipitation)), component (b) is preferably an acidic SL.

[0089] The acidic SL can be prepared by subjecting a mixture of the acidic SL and the lactone SL obtained by the above method to alkaline treatment and hydrolyzing the ester bond in the lactone SL. Examples of alkaline treatment include alkaline reflux method (e.g., JP2006-070231A); however, the alkaline treatment is not limited to this method, and a known alkaline treatment method can be used. For convenience, a commercially available acidic SL can be used. For example, an acidic SL is sold by Saraya Co., Ltd. under the trade name SOFORO (registered trademark) AC-30. This product is an acidic SL having a water content of 70% by mass.

[0090] The proportion of component (b) in the detergent composition of the present invention is preferably adjusted to 3 parts by mass or more per 100 parts by mass of component (a) contained in the detergent composition.

[0091] If the content of component (b) is less than 3 parts by mass per 100 parts by mass of component (a-2), the deterioration of the unsaturated fatty acid contained in the detergent composition due to heat over time cannot be suppressed. In contrast, by incorporating component (b) in an amount of 3 parts by mass or more per 100 parts by mass of component (a-2) in the detergent composition, the decomposition of component (a-2) due to heat can be suppressed, and as a result, the causes of deterioration such as the formation of low molecular weight compounds, coloration and / or odor generation can be eliminated or reduced.

[0092] The lower limit of every 100 mass parts of component (a-2) component (b) ratio is 3 mass parts or more, preferably 5 mass parts or more, more preferably 10 mass parts or more, and even more preferably 15 mass parts or more.From the viewpoint of the above-mentioned effect, the upper limit of the ratio of component (b) is not particularly limited, and from the viewpoint of economy, is such as 500 mass parts or less, preferably 300 mass parts or less, and more preferably 250 mass parts or less.Can select any combination of these lower limit values ​​and upper limit values.Can select such as 3 mass parts to the ratio of component (b) in the range of less than 500 mass parts, 5 mass parts to 300 mass parts or 10 mass parts to 300 mass parts.

[0093] As long as the above conditions are satisfied, the proportion of component (b) based on the detergent composition of the present invention regarded as 100% by mass is not limited, and may be selected from the range of 0.01% by mass to 30% by mass.

[0094] The proportion of component (b) in the detergent composition of the present invention is preferably adjusted so that the proportion of component (b) is 80 parts by mass or less per 100 parts by mass of the total amount of component (a) contained in the detergent composition. The proportion of component (b) is more preferably 70 parts by mass or less, and even more preferably 60 parts by mass or less. If the proportion of component (b) is greater than 80 parts by mass per 100 parts by mass of the total amount of component (a), the foamability, foam firmness and storage stability of the detergent composition tend to decrease.

[0095] The detergent composition of the present invention is preferably adjusted to have a pH in the range of 9 to 11 by using a pH adjuster to exhibit good foaming properties and foam firmness and reduce skin irritation. Examples of pH adjusters include acids, alkali metal salts, and the like. Examples of acids include, but are not limited to, organic acids such as citric acid, malic acid, and succinic acid; and inorganic acids such as sulfuric acid and hydrochloric acid. Examples of alkali metal salts include alkali metal salts such as potassium hydroxide, sodium hydroxide, and potassium carbonate.

[0096] (c) Water

[0097] The detergent composition of the present invention is a liquid composition comprising (c) water in addition to the above-mentioned components (a) and (b). The content of water (c) can be selected from the range of 60% by mass to 97% by mass. The term "liquid" or "liquid" as used herein means that it has fluidity at a temperature of at least 5°C to 50°C.

[0098] The water used in the present invention can be any water that does not impair the effect of the present invention. Preferred examples include purified water, distilled water, ion exchange water and RO water. When the above-mentioned tap water is used as water, it is preferred to use the tap water in combination with a chelating agent to chelate the metal ions contained in the tap water. The amount of the chelating agent used is not limited as long as the metal ions contained in the tap water can be chelated. The amount of the chelating agent can be, for example, about 0.1% by mass; however, the amount of the chelating agent is not limited thereto.

[0099] (d) Optional components

[0100] Depending on the purpose or use, in addition to the above-mentioned components (a) to (c), the detergent composition of the present invention may also contain, for example, the above-mentioned pH adjusters, thickeners (viscosity agents), wetting agents (humectants), chelating agents, anti-inflammatory agents, fragrances, pigments, antioxidants, preservatives, and / or disinfectants as optional components, as long as the effects of the present invention are not impaired.

[0101] Thickener (viscous agent) can be used to increase the viscosity of detergent composition. Various thickeners (viscous agents) that can be added to detergents usually can be used, as long as the effect of the present invention is not damaged. Examples include xanthan gum, guar gum, cationized guar gum, gelatin, hydroxypropyl cellulose, hydroxyethyl cellulose, cationized cellulose and similar modified cellulose, bentonite, carboxyvinyl polymer (carbomer), sodium polyacrylate, polyethylene glycol, polyvinyl alcohol, polyglutamic acid, acrylic acid-methacrylic acid alkyl ester copolymer, alkyl acrylate copolymer etc. These can be used alone or in combination of two or more appropriately.

[0102] Wetting agent (humectant) plays the role of retaining water. Wetting agent (humectant) can also be used to make the components of detergent composition compatible with each other easily and prevent the drying of detergent composition itself. In addition, wetting agent (humectant) can also be used to replenish moisture and soften the object to be cleaned (for example, human skin, human hair and clothes). Any wetting agent can be used as long as it does not damage the effect of the present invention. Specific examples include polyols, such as glycerol, butylene glycol, propylene glycol (propanediol), hexylene glycol (hexylene glycol), dipropylene glycol, propylene glycol (propylene glycol), hexanediol (hexanediol), pentanediol, octanediol, decanediol, diglycerol, and ethylhexylglycerol; amino acids, such as taurine, glutamic acid, glycine, leucine, serine, valine, threonine, alanine, isoleucine, allantoin, phenylalanine, arginine, proline, and tyrosine; and extracts of natural origin, such as perilla extract, rosemary extract, royal jelly extract, and placenta extract. Natural moisturizing factor (NMF) is also useful. Polyols are preferred.

[0103] Chelating agents can be used for the metal ions included in the chelating detergent composition to prevent the obstruction (for example, the foaming of reduction) caused by the metal ions. Any chelating agent can be used, as long as the effect of the present invention is not impaired. Specific examples include salts of organic aminocarboxylic acids (for example EDTA, NTA, DTPA, GLDA, HEDTA, GEDTA, TTHA, HIDA and DHEG).

[0104] Examples of anti-inflammatory agents include, but are not limited to, allantoin, dipotassium glycyrrhizinate, and the like.

[0105] Spices can be used to mask the smell of raw materials or improve preferences. Such spices can be composed of a single fragrance component, or can be a composition comprising a multipolar fragrance component. Any spices can be used as long as the effect of the present invention is not impaired. Specific examples include synthetic spices, such as alcohol-based spices, aldehyde-based spices, ether-based spices, ester-based spices, ketone-based spices, and lactone-based spices; and natural spices derived from plants. Natural spices include, but are not limited to, spices prepared from distillates or fractions of essential oils or plants. Such essential oils are obtained using plants (e.g., flowers, leaves, fruits, peels, bark, roots, seeds) as raw materials.

[0106] The detergent composition of the present invention can be prepared by mixing component (a), component (b) and component (c). If necessary, the detergent composition of the present invention can also be prepared by incorporating the above-mentioned optional component (d) in addition to these components. In the process of preparing the detergent composition, instead of using (adding and incorporating) component (a) itself, component (a) can be produced by stirring the fatty acid constituting component (a) and the hydroxide constituting the salt of component (a) under heating conditions to carry out neutralization reaction. As mentioned above, the detergent composition prepared in this way can be adjusted to have a pH in the range of 9 to 11 using a pH adjusting agent, and it is provided as the detergent composition of the present invention.

[0107] (II) Method for suppressing thermal degradation of detergent composition

[0108] The present invention provides a method for inhibiting thermal degradation of a detergent composition comprising (a) a fatty acid salt.

[0109] The fatty acid salt (a) comprises (a-1) selected from C 14 -C 22 At least one member of the salt of a saturated fatty acid and (a-2) is selected from C 14 -C 22 At least one member of the salts of unsaturated fatty acids.

[0110] This method can be carried out by incorporating (b) SL in an amount of 3 parts by mass or more per 100 parts by mass of component (a-2) in the detergent composition.

[0111] If the content of component (b) is significantly less than 3 parts by mass per 100 parts by mass of component (a-2), the deterioration of the unsaturated fatty acid salt contained in the detergent composition due to heat over time cannot be suppressed. In contrast, by incorporating component (b) in an amount of 3 parts by mass or more per 100 parts by mass of component (a-2) in the detergent composition, the decomposition of component (a-2) due to heat can be suppressed, and as a result, the causes of deterioration such as the formation of low molecular weight compounds, coloration and / or odor generation can be eliminated or reduced.

[0112] Component (a-2) mentioned herein comprises at least one unsaturated fatty acid salt that is easily degraded by heat. Examples of such unsaturated fatty acid salts include unsaturated fatty acid salts having two or more double bonds in the molecule. Specific examples include linoleate, linolenate, eicosadienoate, docosadienoate, meadate and arachidonate.

[0113] The lower limit of the ratio of component (b) is 3 mass parts or more per 100 mass parts of components (a-2), preferably 5 mass parts or more, more preferably 10 mass parts or more, and even more preferably 15 mass parts or more. From the viewpoint of the above-mentioned effect, the upper limit of the ratio of component (b) is not particularly limited, and from an economic point of view, is, for example, 500 mass parts or less, preferably 300 mass parts or less, and more preferably 250 mass parts or less. Any combination of these lower limits and upper limits can be selected. The ratio of the component (b) in the range of, for example, 3 mass parts to less than 500 mass parts, 5 mass parts to 300 mass parts or 10 mass parts to 300 mass parts can be selected.

[0114] As long as the above conditions are satisfied, the proportion of component (b) based on the detergent composition of the present invention regarded as 100% by mass is not limited, and may be selected from the range of 0.01% by mass to 30% by mass.

[0115] In the method of the present invention, the types of component (a-1), component (a-2) and component (b) and the amounts of component (a-1) and component (a-2) are as described in section (I), and the description in section (I) may be incorporated herein by reference.

[0116] Example

[0117] Examples are given below to illustrate the present invention in more detail. However, the present invention is not limited to these specific examples, and various modifications may be added without departing from the scope of the present invention. Unless otherwise stated, the operations in the following experimental examples are carried out at room temperature and atmospheric pressure. "Room temperature" means a temperature in the range of 10°C to 40°C.

[0118] Reference Production Example 1: Preparation of Sophorolipids

[0119] As a culture medium, a liquid culture medium containing 10 g of aqueous glucose (produced by Nihon Shokuhin Kako Co., Ltd., product name: Nisshoku Gansui Kessho Budoto), 10 g of peptone (produced by Oriental Yeast Co., Ltd., product name: Peptone CB90M) and 5 g of yeast extract (produced by Asahi Food & Healthcare Co., Ltd., product name: Meast Powder N) per liter was used. Candida bombus ATCC22214 was cultured in the culture medium while shaking at 30° C. for 2 days. This was used as a preculture liquid.

[0120] The preculture solution was inoculated into a main culture medium (3 L) in a 5-liter fermenter in an amount of 4% by mass, and then cultured for 6 days at 30° C. with an aeration rate of 0.6 vvm for fermentation. The main culture medium contained 100 g of aqueous glucose, 50 g of palm olein (produced by NOF Corporation, product name: Palmary 2000), 50 g of oleic acid (produced by Acid Chem, product name: Palmac 760), 1 g of sodium chloride, 10 g of potassium dihydrogen phosphate, 10 g of magnesium sulfate heptahydrate, 2.5 g of yeast extract (produced by Asahi Food & Healthcare Co., Ltd., product name: Meast Powder N) and 1 g of urea per liter (pH before sterilization was 4.5 to 4.8).

[0121] On the 6th day from the start of cultivation, fermentation was stopped. The culture solution taken out from the fermenter was heated, then returned to room temperature and allowed to stand for 2 to 3 days. As a result, the culture solution was separated into the following three layers in this order from the bottom: a liquid brown precipitate layer, a milky white solid layer that may mainly contain cells, and a supernatant. After removing the supernatant, industrial water or groundwater was added in an amount equal to the amount of the supernatant removed. While the resulting mixture was stirred, a 48% by mass sodium hydroxide aqueous solution was gradually added to adjust the pH to 6.5 to 6.9, thereby dissolving the SL contained in the culture solution. The resulting product was centrifuged with a desktop centrifuge (Westfalia: produced by Westfalia Separator AG) to precipitate the milky white solid, and the supernatant was collected. While stirring the collected supernatant, a 62.5% by mass sulfuric acid aqueous solution was gradually added to adjust the pH to 2.5 to 3.0, thereby indissolving the SL again. After the resulting mixture was allowed to stand for 2 days, the supernatant was removed as much as possible by decantation, thereby obtaining a residue as sophorolipid (SL) (a water-containing product having an SL content of about 50% by mass). The SL-containing aqueous solution contained acid-type SL and lactone-type SL in a ratio (mass ratio) of 30:70.

[0122] Reference Production Example 2: Preparation of Acid Sophorolipids

[0123] The SL-containing aqueous solution obtained in the above Reference Production Example 1 (aqueous product having an SL content of 50% by mass) was adjusted to have a pH of 14 by adding an aqueous sodium hydroxide solution, and treated at 80° C. for 2 hours to perform hydrolysis (alkaline hydrolysis). Subsequently, the hydrolyzate was returned to room temperature and then adjusted to have a pH of 11 by using an aqueous sulfuric acid solution (9.8 M). The resulting insoluble matter was removed by filtration to obtain a filtrate as an aqueous solution containing an acidic SL. The aqueous solution containing an acidic SL contained an acidic SL in an amount of 30% by mass (an aqueous product having an acidic SL content of 30% by mass).

[0124] Experimental Example 1: Preparation and Evaluation of Detergent Compositions

[0125] 1. Preparation of detergent composition

[0126] Detergent compositions (Example 1 and Comparative Example 1) were prepared by mixing the components except the pH adjuster in the ratio shown in Table 1 and finally adjusting the pH to 10 or near 10 using the pH adjuster. As SL of component (b), the aqueous solution containing the acid-type SL prepared in Reference Production Example 2 above (aqueous product having an acid-type SL content of 30% by mass) was used.

[0127] Table 1

[0128]

[0129] *Amount of pH adjuster: an amount such that the pH of the final composition becomes within the range of 9.5 to 10.5 (appropriate amount)

[0130] 2. Evaluation of thermal stability of detergent compositions

[0131] Each of the detergent compositions (Example 1 and Comparative Example 1) prepared above was placed separately in a PET container (50 mL) and allowed to stand at 50° C. in dark conditions for 1 month. After storage, the temperature was returned to room temperature (20° C.), and the resulting samples after storage at 50° C. were subjected to appearance (color tone) evaluation and HPLC analysis by the following method. Thermal stability was evaluated based on the results.

[0132] (1) Appearance (color tone) evaluation

[0133] The appearance (color tone) of each detergent composition (Example 1 and Comparative Example 1) before and after storage at 50°C was compared. As a result, the detergent composition not containing SL (Comparative Example 1) turned yellow (colored) when stored at 50°C for 1 month. In contrast, the detergent composition containing SL (Example 1) showed no difference in color tone compared to before storage. These results confirm that incorporating SL into a detergent composition containing a saturated fatty acid salt and an unsaturated fatty acid salt suppresses coloration that occurs under heating conditions.

[0134] (2) HPLC analysis and evaluation

[0135] Samples of each detergent composition (Example 1 and Comparative Example 1) before and after storage at 50°C were subjected to HPLC under the following conditions.

[0136] HPLC conditions

[0137] HPLC equipment: Prominece-i 2030 (manufactured by Shimadzu Corporation)

[0138] Column: Inersil ODS-3 (φ4.6 mm×150 mm) (manufactured by GL Sciences)

[0139] Mobile phase: acetonitrile: purified water: formic acid = 70:30:0.1 (volume ratio)

[0140] Flow rate: 1.0ml / min

[0141] Column temperature: 40°C

[0142] Detection: UV 215nm

[0143] Preliminary analysis using standard products of unsaturated fatty acids (linoleic acid and oleic acid) confirmed that the retention time of linoleic acid under the above HPLC conditions was 25.5 minutes, and the retention time of oleic acid under the above HPLC conditions was 42.5 minutes.

[0144] Figure 1-1 and Figure 1-2 HPLC chromatograms of a sample of the detergent composition (Example 1) before and after storage at 50° C. are shown respectively. Figure 2-1 and Figure 2-2 HPLC chromatograms of a sample of the detergent composition (Comparative Example 1) before and after storage at 50° C. are shown respectively.

[0145] Table 2 shows changes in linoleic acid content (%) calculated from the peak area of ​​linoleic acid determined from the chromatogram of each sample before and after storage at 50°C.

[0146] Table 2

[0147]

[0148] *1: Change in the linoleic acid content in the sample of Comparative Example 1 before storage at 50°C relative to 100% by mass

[0149] *2: Change in the linoleic acid content in the sample of Example 1 before storage at 50°C relative to 100% by mass

[0150] As shown in Table 2, when the composition was stored at 50°C, the peak of linoleic acid in the detergent composition not containing SL (Comparative Example 1) decreased by 17.1%. Figure 2-2 As shown in FIG. 1 , in the chromatogram of the sample stored at 50° C., several peaks of low molecular weight compounds considered to be decomposition products of linoleic acid were observed at retention times of 0 to 12.5 minutes. In contrast, it was confirmed that even when the detergent composition containing SL (Example 1) was stored at 50° C., the decomposition of linoleic acid in the composition was significantly suppressed (see Figure 1-2 ).

[0151] Experimental Example 2: Preparation and Evaluation of Detergent Compositions

[0152] 1. Preparation of detergent composition

[0153] The detergent compositions (Examples 1 to 11 and Comparative Examples 1 to 18) were prepared by mixing the components except the pH adjuster in the ratios shown in Tables 3 to 5 and adjusting the pH to 10 or near 10 using the pH adjuster. As SL of component (b), the aqueous solution containing the acid-type SL prepared in Reference Production Example 2 above (aqueous product having an acid-type SL content of 30% by mass) or the aqueous solution containing SL prepared in Reference Production Example 1 (aqueous product having an SL content of 50% by mass) was used.

[0154] 2. Evaluation of detergent composition

[0155] The detergent compositions (Examples 1 to 11 and Comparative Examples 1 to 18) prepared above were evaluated for thermal stability, metal soap-forming properties, skin irritation, stability at low temperatures, and foaming properties by the following methods.

[0156] 2-1. Evaluation of thermal stability

[0157] The thermal stability of each detergent composition was evaluated by storing the detergent composition under heating conditions at 50°C and under conditions at -5°C for a predetermined period of time, respectively, and comparing (1) the content of unsaturated fatty acid (linoleic acid), (2) the color tone of the detergent composition, and (3) the odor between the two conditions. Preliminary tests confirmed that each detergent composition was stable after storage at -5°C for 4 weeks, with no significant changes in the content of unsaturated fatty acid (linoleic acid), color tone or odor.

[0158] (1) Measurement of unsaturated fatty acid (linoleic acid) content: Effect of inhibiting deterioration of unsaturated fatty acid salts Evaluate

[0159] Each detergent composition (Examples 1 to 11 and Comparative Examples 1 to 18) was divided into two groups, namely, a group stored at 50°C and a group stored at -5°C. Samples of the group stored at 50°C and the group stored at -5°C were each placed in a PET container (50 mL), and then allowed to stand at 50°C and -5°C under dark conditions for 4 weeks, respectively. After storage, the resulting samples of each group (samples stored at 50°C and samples stored at -5°C) were subjected to HPLC under the same conditions as in Experimental Example 1 (2) to analyze the content of unsaturated fatty acid (linoleic acid).

[0160] Based on the chromatograms obtained for the samples stored at -5°C and the samples stored at 50°C of each detergent composition, the peak areas of linoleic acid in the two samples were compared, and the residual percentage of linoleic acid in the sample stored at 50°C was determined using the following formula. Since the linoleic acid in each detergent composition is stable under the storage condition of -5°C as described above, the presence or absence of deterioration of unsaturated fatty acids in each detergent composition under heating conditions (thermal stability) can be determined from the residual percentage of linoleic acid in the sample stored at 50°C obtained using the following formula. It can be evaluated that the higher the residual percentage, the higher the effect of suppressing the thermal decomposition of unsaturated fatty acids (thermal stability effect).

[0161] Formula: Residual percentage (%) = (A / B) × 100

[0162] A: Peak area of ​​linoleic acid in samples stored at 50°C

[0163] B: Peak area of ​​linoleic acid in samples stored at -5°C

[0164] From the residual percentage obtained using the above formula, the effect of suppressing the degradation of the unsaturated fatty acid salt was evaluated based on the following criteria.

[0165] Criteria for evaluating the effect of inhibiting the deterioration of unsaturated fatty acid salts

[0166] ◎: 90% or more residual percentage

[0167] ○: Residual percentage of 85% or more and less than 90%

[0168] ×: Less than 85% residual percentage

[0169] (2) Measurement of color tone changes: Evaluation of coloration suppression effects

[0170] Five trained expert panelists visually compared the color tones of the samples stored at -5°C and the samples stored at 50°C of each detergent composition, and answered whether there was a difference between the color tones of the two samples. As described above, the color tones of each detergent composition did not change when stored at -5°C. Therefore, when the color tones of the samples stored at 50°C are not different from the color tones of the samples stored at -5°C, it can be evaluated that the effect of suppressing the color tones change (coloration) caused by heating (coloration suppression effect) is high.

[0171] The coloration-inhibiting effect of each detergent composition was evaluated based on the following criteria according to the number of panelists who answered that the color tone of the sample stored at 50°C was not different from the color tone of the sample stored at -5°C.

[0172] Criteria for evaluating coloration suppression effects

[0173] ◎: The number of panelists who answered that there was no difference was 5.

[0174] ○: The number of panelists who answered that there was no difference was 4.

[0175] △: The number of panelists who answered that there was no difference was 2 to 3.

[0176] ×: The number of panelists who answered that there is no difference is 1 or less.

[0177] (3) Measurement of odor changes: Evaluation of odor change suppression effects

[0178] Five trained expert panelists compared the odors of samples stored at -5°C and samples stored at 50°C of each detergent composition, and answered whether there was a difference between the odors of the two samples. As described above, the odor of each detergent composition did not change when stored at -5°C. Therefore, when the odor of the sample stored at 50°C is not different from the odor of the sample stored at -5°C, it can be evaluated that the effect of suppressing the odor change caused by heating (odor change suppression effect) is high.

[0179] According to the number of panelists who answered that the odor of the sample stored at 50°C was not different from that of the sample stored at -5°C, the odor generation suppressive effect of each detergent composition was evaluated based on the following criteria.

[0180] Criteria for evaluating the inhibitory effect of odor generation

[0181] ◎: The number of panelists who answered that there was no difference was 5.

[0182] ○: The number of panelists who answered that there was no difference was 4.

[0183] △: The number of panelists who answered that there was no difference was 2 to 3.

[0184] ×: The number of panelists who answered that there is no difference is 1 or less.

[0185] 2-2. Evaluation of the metal soap formation inhibition effect

[0186] The metal soap formation inhibitory effect of each detergent composition is evaluated based on the turbidity of the liquid produced by adding calcium chloride to each detergent composition. Specifically, 1mM calcium chloride aqueous solution is added to each detergent composition so that the total concentration of fatty acid salt is 2mM. After stirring, the turbidity of the liquid is converted into transmittance by measuring the absorbance at 550nm. It can be evaluated that the lower the transmittance is, the higher the amount of the metal soap formed, and the higher the metal soap formation characteristic (the lower the metal soap formation inhibitory effect is), and the higher the transmittance is, the lower the amount of the metal soap formed, and it is less likely to form metal soap (the higher the metal soap formation inhibitory effect is).

[0187] From the measured transmittance, the metal soap formation inhibitory effect of each detergent composition was evaluated based on the following criteria.

[0188] Criteria for evaluating the inhibition of metal soap formation

[0189] ◎: Transmittance of 50% or more

[0190] ○: Transmittance of 40% or more and less than 50%

[0191] ×: Transmittance less than 40%

[0192] 2-3. Evaluation of skin irritation

[0193] Skin irritation testing was performed based on OECD test guideline TG439 (In vitro skin irritation: reconstructed human epidermis test method).

[0194] After preparing each detergent composition, 25 μL of the detergent composition was added to a three-dimensional cultured skin model (LabCyte EPI-MODEL 24 produced by J-TEC). After 15 minutes of exposure, the model was washed with PBS to remove the detergent composition. After 42 hours of cultivation, the culture was carried out again in a culture medium supplemented with MTT, and living cells were stained. Subsequently, the dye was extracted with isopropanol and the absorbance (570nm) of the extract was measured. As a negative control, purified water was used in the same manner instead of the detergent composition as a test sample for testing.

[0195] The cell viability of the cultured skin to which each cleansing composition was added was calculated using the following formula.

[0196] Cell viability (%) = (A / B) × 100

[0197] a: Average absorbance measured using each detergent composition as a test sample

[0198] b: Average absorbance measured using purified water as the test sample (negative control)

[0199] Based on OECD TG439, ​​the skin irritation of each detergent composition was evaluated according to the following criteria.

[0200] Criteria for evaluating skin irritation

[0201] ◎Non-irritating: Cell viability is 50% or greater.

[0202] × Irritant: Cell viability is less than 50%.

[0203] 2-4. Stability at low temperatures

[0204] After preparing each detergent composition, the detergent composition was placed in a PET container (50 mL) and stored in a dark condition at 5° C. for 4 weeks, and the liquid state of the detergent composition was visually observed over time to evaluate the presence or absence of precipitation, floating matter, and solid-liquid separation. The stability at low temperature was evaluated based on the following criteria.

[0205] Criteria for evaluating stability at low temperatures

[0206] ◎: During the 4-week storage period, no precipitation, floating matter, or solid-liquid separation was observed, and the components were uniformly dissolved.

[0207] ○: During the 1-week storage period, no precipitation, floating matter, or solid-liquid separation was observed, and the components were uniformly dissolved. However, after 1-week storage, precipitation, floating matter, or solid-liquid separation was observed.

[0208] ×: During the 1-week storage period, precipitation, floating matter, or solid-liquid separation was observed.

[0209] 2-5. Foaming properties (foaming characteristics)

[0210] 2.5 mL of sample and 2.5 mL of tap water were placed in a test tube (18 mm diameter x 180 mm length) and stirred for 20 seconds with a vortex mixer. The amount of bubbles in the sample (the length from the liquid surface to the top of the bubble in the test tube (foam height)) was measured immediately after stirring. The test was performed at room temperature (25 ± 5 °C).

[0211] Criteria for evaluating foaming properties

[0212] ○: The height of the foam immediately after stirring is 10 mm or more.

[0213] ×: The height of the foam immediately after stirring is less than 10 mm.

[0214] Tables 3 to 5 show the formulations and evaluation results of the respective detergent compositions (Examples 1 to 11 and Comparative Examples 1 to 18).

[0215] Table 3

[0216]

[0217] Table 4

[0218]

[0219] Table 5

[0220]

[0221] The detergent compositions of Examples 1 to 11 contain (a-1) one or more saturated fatty acid salts having 14 or more carbon atoms and (a-2) unsaturated fatty acid salts having 14 or more carbon atoms as (a) fatty acid salts and (b) SL. In each detergent composition, based on the composition regarded as 100% by mass, the proportion of component (a) is in the range of 2% by mass to 35% by mass, based on 100 parts by mass of the total amount of component (a), the proportion of component (a-2) is 20 parts by mass or more, and the proportion of component (b) is 3 parts by mass or more per 100 parts by mass of component (a-2). As shown in Table 3, it was confirmed that all of these detergent compositions have low skin irritation, high thermal stability (unsaturated fatty acid salt deterioration inhibition effect, coloring inhibition effect and odor generation inhibition effect), and good stability and foaming properties at low temperatures, and further confirmed that metal soap formation is inhibited.

[0222] In contrast, the detergent compositions not containing unsaturated fatty acid salts (Comparative Examples 3 and 9 to 13) all have high metal soap formation characteristics and do not have a metal soap formation inhibitory effect. The detergent compositions containing one or more unsaturated fatty acid salts in an amount of less than 20 parts by mass based on 100 parts by mass of the total amount of the fatty acid salts (Comparative Examples 7, 8 and 14 to 16) also have high metal soap formation characteristics and do not have a metal soap formation inhibitory effect (Tables 4 and 5). When such detergent compositions are used for body washing, the large amount of metal soap formed causes a creaking sensation and a tight feeling of the skin, and when such detergent compositions are used for washing dishes, clothes and houses, the large amount of metal soap formed causes white residues.

[0223] In contrast, detergent compositions containing one or more unsaturated fatty acid salts in an amount of 20 parts by mass or more based on 100 parts by mass of the total amount of the fatty acid salts (Examples 1 to 11 and Comparative Examples 4 to 6, 17 and 18) had a high metal soap formation inhibitory effect and produced less metal soap when diluted with tap water (see Tables 3 to 5). These results confirm that a detergent composition having a high metal soap formation inhibitory effect and producing less metal soap can be prepared by setting the ratio of the one or more unsaturated fatty acid salts to 20 parts by mass or more based on 100 parts by mass of the total amount of the fatty acid salts.

[0224] The detergent compositions of Comparative Examples 1, 2, and 4 to 6 all had poor thermal stability, and unsaturated fatty acid deterioration, coloration, and odor generation were observed when they were stored at 50° C. In contrast, the detergent composition (Comparative Example 3) not containing an unsaturated fatty acid salt had good thermal stability (suppression of coloration and suppression of odor generation) (see Table 4). Considering the results of Experimental Example 1 above, it is believed that the coloration and odor generation caused by storage at 50° C. are due to the deterioration (decomposition into low molecular weight compounds) of the unsaturated fatty acid salt contained in the detergent composition.

[0225] The detergent compositions (Examples 1 to 11 and Comparative Examples 14 to 18) containing one or more unsaturated fatty acid salts and 3 parts by mass or more of SL per 100 parts by mass of the one or more unsaturated fatty acid salts have good thermal stability (inhibition of deterioration of the unsaturated fatty acid salts, inhibition of coloration, and inhibition of odor generation) (see Tables 3 and 5). In contrast, the detergent composition of Comparative Example 5 containing an unsaturated fatty acid salt and 2.3 parts by mass of SL per 100 parts by mass of the unsaturated fatty acid salt has poor thermal stability (see Table 4).

[0226] These results confirm that thermal stability problems (unsaturated fatty acid deterioration, coloration, odor generation) caused by incorporating unsaturated fatty acid salts as fatty acid salts can be reduced or solved by incorporating SL in an amount of 3 parts by mass or more per 100 parts by mass of unsaturated fatty acid salts.

[0227] The detergent compositions (embodiments 1 to 11 and comparative examples 1 to 3) that do not contain fatty acid salts having less than 14 carbon atoms are all less irritating to the skin. In contrast, it is found that the detergent compositions (comparative examples 4 to 18) that contain one or more fatty acid salts having less than 14 carbon atoms are all irritating to the skin. According to the result of Experimental Example 3 described below, it is believed that the skin irritation of the detergent composition is due to the fatty acid salts having less than 14 carbon atoms, particularly the saturated fatty acid salts having 12 carbon atoms. This confirms that a detergent composition that is less irritating to the skin can be prepared by using fatty acid salts having 14 or more carbon atoms without using fatty acid salts having less than 14 carbon atoms as fatty acid salts. That is, the detergent composition that does not contain fatty acid salts having less than 14 carbon atoms is less irritating to the skin, and therefore can be appropriately used as a detergent composition for the body or hair of babies with delicate skin and people with sensitive skin.

[0228] Does not contain C 14 -C 22 The detergent composition containing unsaturated fatty acid salt (Comparative Example 3) and the detergent composition containing 40% by mass of fatty acid salt (Comparative Example 6) had poor stability at low temperature (Table 4). 14 -C 22 The detergent compositions of unsaturated fatty acid salts (Examples 1 to 11 and Comparative Examples 1, 2, 4, 5, 7, 8 and 14 to 18) and the detergent compositions containing no unsaturated fatty acid salts but containing one or more saturated fatty acid salts having less than 14 carbon atoms (Comparative Examples 9 to 13) all have good stability at low temperatures (Tables 3 and 5). All of these detergent compositions have a fatty acid salt content of 35% by mass or less.

[0229] These results confirm that by incorporating C 14 -C 22 Unsaturated fatty acid salts are added and the total fatty acid salt content is adjusted to 35 mass % or less to prepare a detergent composition having good stability at low temperatures.

[0230] All of the detergent compositions (Examples 1 to 11 and Comparative Examples 1 to 18) contained the fatty acid salt in an amount of 2% by mass or more of the total amount, and were confirmed to have foaming properties required as detergent compositions.

[0231] Experimental Example 3: Evaluation of skin irritation

[0232] The skin irritation of alkali metal salts of various fatty acids (potassium laurate, potassium myristate, potassium palmitate and potassium oleate) was evaluated by the following method based on OECD test guideline TG439.

[0233] (1) Evaluation method

[0234] 1) Each culture insert of the human three-dimensional cultured epidermis model was individually transferred to a well containing 0.5 mL of an assay medium and pre-cultured in a CO 2 incubator for about 24 hours.

[0235] 2) 25 μL of each test sample (each 0.1 M fatty acid aqueous solution) was added individually to the surface of the cultured epidermis, followed by exposure for 15 minutes (N=3).

[0236] 3) Wash the sample from each culture insert with sterile PBS (repeat the wash 15 times or more to completely remove the test sample).

[0237] 4) Each washed culture insert was transferred to a well containing 1 mL of fresh assay medium and subjected to post-treatment incubation in a CO2 incubator for 42 hours.

[0238] 5) After the culture, each culture insert was transferred to a well containing 0.5 mL of MTT culture medium and cultured in a CO 2 incubator for 3 hours.

[0239] 6) The cultured epidermis in each culture insert was taken out with forceps and placed in a microtube, 300 μL of isopropanol was added thereto to completely immerse the cultured epidermis, the cultured epidermis was allowed to stand overnight or longer, and the dye was extracted.

[0240] 7) Place 200 μL of the solution in the microtube into each well of a 96-well plate, and measure the absorbance at 570 nm using a plate reader.

[0241] (2) Evaluation results

[0242] As a negative control, the same test was performed using purified water instead of the fatty acid solution as a test sample. The viability (%) of the cells exposed to the fatty acid solution was determined in the same manner as described in Parts 2 to 3 of Experimental Example 2.

[0243] Figure 3 Results are shown.Based on OECD TG439, ​​cell viability ≤ 50% was considered stimulatory and cell viability > 50% was considered non-stimulatory.

[0244] like Figure 3 As shown, it is determined to be C 12 Lauric acid salts of saturated fatty acids are irritants, and salts of saturated or unsaturated fatty acids having 14 or more carbon atoms are determined to be non-irritants.

[0245] Industrial Applicability

[0246] The detergent composition of the present invention has good stability, less irritation to the skin, and gives excellent feeling during use. Therefore, the detergent composition of the present invention can be used to clean the human body (e.g., hair and body, including hands and face), tableware, house, clothes and anything in daily life.

Claims

1. A liquid detergent composition comprising: (a) fatty acid salts; and (b) sophorolipids, in The fatty acid salt (a) comprises (a-1) selected from C 14 -C 22 At least one member of the salt of a saturated fatty acid and (a-2) is selected from C 14 -C 22 at least one member of the salts of unsaturated fatty acids, and The components are included in the following proportions: A) the total amount of component (a) is 2% to 35% by mass based on the detergent composition regarded as 100% by mass; B) the proportion of component (a-2) is 20 parts by mass or more based on 100 parts by mass of the total amount of the component (a); and C) The proportion of the component (b) is 3 parts by mass or more per 100 parts by mass of the component (a-2). 2 . The detergent composition according to claim 1 , wherein B) the proportion of the component (a-2) is 20 to 95 parts by mass based on 100 parts by mass of the total amount of the component (a).

3. The detergent composition according to claim 1 or 2, wherein the proportion of C) the component (b) is 3 to 500 parts by mass per 100 parts by mass of the component (a-2).

4. The detergent composition according to claim 1 or 2, wherein A) the total amount of the component (a) is 3 to 32 mass% based on the detergent composition regarded as 100 mass%.

5. The cleaning composition according to claim 1 or 2, in The component (a-1) is a salt of at least one member selected from the group consisting of myristic acid, palmitic acid, isopalmitic acid, stearic acid, isostearic acid and arachidic acid, and The component (a-2) is a salt of at least one member selected from the group consisting of oleic acid, linoleic acid, linolenic acid, palmitoleic acid, arachidonic acid, eicosenoic acid, erucic acid, eicosadienoic acid, docosadienoic acid and mead acid.

6. A method for inhibiting thermal degradation of a detergent composition comprising (a) a fatty acid salt, wherein the fatty acid salt (a) comprises (a-1) selected from C 14 -C 22 At least one member of the salt of a saturated fatty acid and (a-2) is selected from C 14 -C 22 At least one member of a salt of an unsaturated fatty acid, the method comprising incorporating (b) a sophorolipid in an amount of 3 parts by mass or more per 100 parts by mass of the component (a-2) into the detergent composition.

7. The method according to claim 6, wherein the detergent composition comprises as the component (a-2) a salt of at least one unsaturated fatty acid selected from linoleic acid, linolenic acid, eicosadienoic acid, docosadienoic acid, mead acid and arachidonic acid.

8. The method according to claim 6 or 7, wherein the detergent composition comprises the component (a) and the component (a-2) in the following ratio: A) the total amount of the component (a) is 2% to 35% by mass based on the detergent composition regarded as 100% by mass; and B) The proportion of the component (a-2) is 20 parts by mass or more based on 100 parts by mass of the total amount of the component (a).

9. The method according to claim 8, wherein A) the total amount of the component (a) is 3 to 32 mass% based on the detergent composition regarded as 100 mass%. 10 . The method according to claim 8 , wherein B) the proportion of the component (a-2) is 20 parts by mass to 95 parts by mass based on 100 parts by mass of the total amount of the component (a).

11. The method according to claim 6 or 7, wherein the proportion of the component (b) is 3 parts by mass to 500 parts by mass per 100 parts by mass of the component (a-2).

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