JP7500489B2 - Liquid cleaning composition - Google Patents

Description

The present invention relates to a liquid cleaning composition.

Alkali metal salts of fatty acids, so-called fatty acid soaps, have been used as cleaning agents for a long time and are produced by saponification of vegetable oils and fats, or by neutralization of fatty acids with potassium hydroxide or sodium hydroxide. Many of the vegetable oils used in saponification contain unsaturated fatty acids, but unsaturated fatty acids are generally prone to oxidation, and alkali metal salts of fatty acids containing unsaturated fatty acids have problems such as the generation of a deteriorated odor and changes in color over time.
As a countermeasure, antioxidants such as tocopherol are generally used in oils and fats containing unsaturated fatty acids (Patent Document 1), and soap products containing tocopherol for their antioxidant effect are also widely available.
When antioxidants are not used, there is a method of masking the odor of deterioration with fragrances, but this is not a fundamental solution.

Japanese Patent Application Laid-Open No. 57-179297

The object of the present invention is to provide a novel liquid detergent composition containing an alkali metal salt of a fatty acid, including an unsaturated fatty acid, which is suppressed from changing in color over time and from generating a deterioration odor.

As a result of extensive research, the inventors have discovered that by incorporating a specific amount of one or more compounds selected from the group consisting of pyrrolidone carboxylic acid and its salts, it is possible to suppress the color change and the generation of a deterioration odor of the liquid detergent composition over time while maintaining suitability for use as a liquid detergent, and thus completed the present invention.

According to the present invention, the following liquid cleaning composition and the like can be provided.
1. A liquid cleaning composition comprising:
The composition contains, based on the entire composition, 3 to 36 mass% of an alkali metal salt of a fatty acid including an unsaturated fatty acid, and 0.01 to 10.3 mass% of one or more types selected from the group consisting of pyrrolidone carboxylic acid and salts thereof.
2. The liquid detergent composition according to 1, which satisfies the following formula (1) or (2), when the content of the alkali metal salt of the fatty acid is x [% by mass] and the upper limit of the content of the one or more selected from the group consisting of pyrrolidone carboxylic acid and salts thereof is y [% by mass]:
(1) When x is 3 mass% or more and 20 mass% or less, y = 0.4x + 2.25
(2) When x is greater than 20% by mass and less than 36% by mass, y = -0.17x + 13.5
3. The liquid detergent composition according to 1 or 2, wherein the unsaturated fatty acid is at least one selected from the group consisting of oleic acid, linoleic acid, linolenic acid, palmitoleic acid, eicosenoic acid, and erucic acid.
4. The liquid detergent composition according to any one of 1 to 3, wherein in the alkali metal salt of the fatty acid, a molar ratio of the sodium salt to the potassium salt is from 0:10 to 4:6.

The present invention provides a novel liquid detergent composition containing an alkali metal salt of a fatty acid, including an unsaturated fatty acid, which is suppressed from changing color over time and from generating a deterioration odor.

FIG. 1 is a graph showing the correlation between the fatty acid potassium content and the upper limit of the sodium pyrrolidone carboxylate content in Examples 10 to 19.

Hereinafter, embodiments of the liquid detergent composition of the present invention will be specifically described.
Herein, a preferred aspect of one feature may be combined in any manner with a preferred aspect of one or more other features.
In addition, in this specification, the description of "X to Y" indicating a numerical range means "X or more and Y or less," and for each parameter, the lower limit value and the upper limit value can be arbitrarily combined to form a numerical range.

The liquid detergent composition of the present invention is characterized by containing, based on the total mass of the composition, 3 to 36 mass% of an alkali metal salt of a fatty acid, including an unsaturated fatty acid, and 0.01 to 10.3 mass% of one or more types selected from the group consisting of pyrrolidonecarboxylic acid and salts thereof.
The liquid cleaning composition of the present invention, by incorporating one or more compounds selected from the group consisting of pyrrolidone carboxylic acids and their salts in a specific amount, can achieve the effect of suppressing color change over time and the generation of a deterioration odor, and furthermore can be made suitable for use as a liquid cleaning agent.

In this specification, "liquid" means that the viscosity is 20,000 mPa·s or less when measured using a B-type viscometer (product name: VISCOMETER (MODEL LVP), manufactured by BROOKFIELD) with rotor No. 4 at 25°C after rotating at 30 rpm for 1 minute. This viscosity range means that the material has fluidity that indicates suitability for use as a liquid cleaning agent.

In the liquid detergent composition of the present invention, the fatty acid constituting the alkali metal salt of a fatty acid is one or more types selected from the group consisting of saturated fatty acids and unsaturated fatty acids, and includes unsaturated fatty acids.
The alkali metal salt is a salt of an alkali metal element, and examples thereof include sodium salts and potassium salts.

In the liquid detergent composition of the present invention, the content of the alkali metal salt of a fatty acid, including an unsaturated fatty acid, is 3 to 36% by mass, preferably 5 to 35% by mass, and more preferably 10 to 35% by mass, based on the total mass of the composition.

Examples of saturated fatty acids include caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, etc. Caprylic acid, capric acid, lauric acid, and myristic acid themselves have an unpleasant odor, and sodium or potassium salts of caprylic acid, capric acid, and lauric acid are skin irritants. Therefore, the content of saturated fatty acids having 14 or less carbon atoms in the liquid detergent composition is preferably 90% by mass or less, more preferably 80% by mass or less, and even more preferably 65% by mass or less, based on the total fatty acid content. If there is a large amount of saturated fatty acids having 16 or more carbon atoms such as palmitic acid and stearic acid, the viscosity of the resulting detergent composition tends to increase, and in some cases the detergent composition may solidify, so the content of saturated fatty acids having 16 or more carbon atoms in the liquid detergent composition is preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less, based on the total fatty acid content.

Examples of unsaturated fatty acids include oleic acid, linoleic acid, linolenic acid, palmitoleic acid, eicosenoic acid, and erucic acid.
The ratio of saturated fatty acids to unsaturated fatty acids in the liquid detergent composition ("content of saturated fatty acids:content of unsaturated fatty acids (mass ratio)") is not particularly limited and is, for example, 20:80 to 95:5, preferably 25:75 to 93:7, and more preferably 30:70 to 90:10.

In the liquid detergent composition of the present invention, the molar ratio of the sodium salt to the potassium salt in the alkali metal salt of the fatty acid is preferably 0:10 to 4:6, and more preferably 0:10 to 3:7. By being in the above range, the content of the alkali metal salt of the fatty acid in the detergent composition can be increased by 0.1 to 1.0 mass % while maintaining the properties of the detergent composition in a liquid state.

In the liquid detergent composition of the present invention, the content of one or more selected from the group consisting of pyrrolidone carboxylic acid and its salts is 0.01 to 10.3 mass% based on the total composition, preferably 0.01 to 8.5 mass%, more preferably 0.1 to 5.0 mass%, even more preferably 0.25 to 3.0 mass%, and even more preferably 0.25 to 1.5 mass%.

Examples of salts of pyrrolidone carboxylic acid include sodium, zinc, potassium and the like salts.
Sodium pyrrolidone carboxylate is known to be a moisturizing component that plays an important role among natural moisturizing factors, but in the liquid cleansing composition of the present invention, it is a new finding that was not previously known that by using sodium pyrrolidone carboxylate in combination with an alkali metal salt of a fatty acid, including an unsaturated fatty acid, at a specific content ratio, it is possible to suppress color change over time and the generation of a deterioration odor.

It is preferable that the liquid detergent composition of the present invention satisfies the following formula (1) or (2) when the content of the alkali metal salt of the fatty acid is x [mass%] and the upper limit of the content of the one or more selected from the group consisting of pyrrolidone carboxylic acid and salts thereof is y [mass%].
(1) When x is 3 mass% or more and 20 mass% or less, y = 0.4x + 2.25
(2) When x is greater than 20% by mass and less than 36% by mass, y = -0.17x + 13.5
Formulas (1) and (2) are empirical formulas which show the correlation between the content of the alkali metal salt of a fatty acid and the upper limit of the content of one or more selected from the group consisting of pyrrolidone carboxylic acid and its salts, which were derived through the study in the Examples described later.
The liquid detergent composition of the present invention contains a specific content of an alkali metal salt of a fatty acid and, in contrast, contains a specific content of one or more types selected from the group consisting of pyrrolidone carboxylic acid and its salts, thereby making it possible to suppress the generation of deterioration odors that occur over time, etc. In particular, by specifying the upper limit of the content of one or more types selected from the group consisting of pyrrolidone carboxylic acid and its salts in accordance with formulas (1) and (2), phase separation of the liquid detergent composition can be suppressed to make it a homogeneous solution.

In one embodiment of the liquid detergent composition of the present invention, the mass ratio of the alkali metal salt of a fatty acid to one or more selected from the group consisting of pyrrolidonecarboxylic acid and salts thereof is, for example, 1:0.001 to 1:0.600, preferably 1:0.003 to 1:0.400, and more preferably 1:0.005 to 1:0.200.
The liquid cleaning composition of the present invention contains a specific content of an alkali metal salt of a fatty acid, and in contrast, contains a specific content of one or more types selected from the group consisting of pyrrolidone carboxylic acid and its salts, thereby making it possible to suppress the generation of deterioration odors that occur over time, etc.

The liquid detergent composition of the present invention can be used as a detergent product as it is, or may further contain, as optional components, anionic surfactants other than alkali metal salts of fatty acids, cationic surfactants, amphoteric surfactants, nonionic surfactants, moisturizers, thickeners, fragrances, pH adjusters, extract components, cleaning aids, preservatives, etc.
In the cleaning agent product, the content of the liquid cleaning agent composition of the present invention is, for example, 60 mass% or more, 70 mass% or more, 80 mass% or more, 90 mass% or more, 95 mass% or more, 98 mass% or more, or 100 mass% based on the entire product.
When the cleaning agent product contains the above-mentioned optional components, the content of the optional components is, for example, 40% by mass or less, 30% by mass or less, 20% by mass or less, 10% by mass or less, or 2% by mass or less based on the entire product.

As the anionic surfactant other than the alkali metal salt of a fatty acid, any surfactant known in the art can be used, and examples thereof include alkyl ether carboxylates, alkyl sulfates, alkyl sulfonates, alkyl ether sulfosuccinates, alkyl phosphates, alkyl ether phosphates, and acylamino acid salts.
As the cationic surfactant, any one known in the art can be used, and examples thereof include alkyltrimethylammonium salts, dialkyldimethylammonium salts, alkylammonium salts, benzalkonium salts, benzethonium salts, pyridinium salts, imidazolinium salts, and the like.
Any amphoteric surfactant known in the art may be used, and examples thereof include alkyl acetate betaines, imidazolinium betaines, alkyl amidopropyl betaines, and alkyl hydroxysulfobetaines.

The nonionic surfactant may be any surfactant known in the art, and examples thereof include silicone-based surfactants such as glycerin fatty acid esters, polyoxyethylene glycerin fatty acid esters, polyglycerin fatty acid esters, propylene glycol fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitol-sorbitan fatty acid esters, polyoxyethylene castor oil, polyoxyethylene hydrogenated castor oil, ethylene glycol fatty acid esters, polyethylene glycol fatty acid esters, alkyl glyceryl ethers, polyoxyethylene alkyl ethers, polyoxyethylene alkyl ether fatty acid esters, and polyether-modified silicones.
These surfactants can be selected from those generally used in cosmetics and cleansing agents.

As the moisturizer, any one known in the art can be used, such as glycerin, 1,3-butylene glycol, 1,2-pentanediol, propanediol, betaine, trehalose, sorbitol, xylitol, etc. These may be used alone or in combination of two or more.

Any thickener known in the art can be used, including, for example, natural polymers such as xanthan gum, carrageenan, guar gum, tamarind gum, and sodium alginate; semi-synthetic polymers such as methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, carboxymethylcellulose, cationized guar gum, and cationized cellulose; and synthetic polymers such as carboxyvinyl polymer, polyvinyl alcohol, polyvinylpyrrolidone, polyacrylic acid, methacryloylethylbetaine-methacrylic acid ester copolymer, and dimethylallylammonium chloride-acrylamide copolymer. These may be used alone or in combination of two or more. By using a thickener, the liquid detergent composition can be made to have suitable properties for its intended use.

As the fragrance, any of those known in the art can be used, for example, isolated or synthetic fragrances such as limonene, geraniol, linalool, citral, and essential oils such as lavender oil, peppermint oil, orange oil, ylang-ylang oil, frankincense oil, laurel oil, and rosewood oil. These may be used alone or in combination of two or more.

As the pH adjuster, any inorganic acid, organic acid, inorganic base, or organic base known in the art can be used. Among them, organic acids and inorganic bases are preferred, and for example, organic acids include citric acid, lactic acid, butyric acid, glycolic acid, etc., and inorganic bases include potassium hydroxide, sodium hydroxide, etc. These may be used alone or in combination of two or more.
The pH of the liquid detergent composition of the present invention is not particularly limited, but from the viewpoints of detergency and skin irritation, it is preferably from 8.5 to 10.99.

As the extract ingredient, any ingredient known in the art can be used, for example, Angelica extract, Acacia oleracea extract, Avocado extract, Amacha extract, Gynostemma pentaphyllum extract, Altea extract, Arnica extract, oil-soluble Arnica extract, Almond extract, Aloe extract, Ansokko extract, Ginkgo extract, Nettle extract, Iris root extract, Fennel extract, Turmeric extract, Ajing extract, Echinacea leaf extract, Scutellaria root extract, Phellodendron bark extract, Coptis extract, Barley extract, Okra extract, Extract, Hypericum extract, oil-soluble Hypericum extract, Lamium extract, oil-soluble Lamium extract, Ononis extract, Watercress extract, Orange extract, Orange flower water, Seaweed extract, Persimmon tannin, Pueraria root extract, Valerian extract, Cattail extract, Chamomilla extract, oil-soluble chamomilla extract, Chamomilla water, Oat extract, Carrot extract, oil-soluble carrot extract, Carrot oil, Artemisia capillaris extract, Licorice extract, Licorice extract powder, Licorice flavonoid, Cantharides tincture, Key Chigo extract, kiwi extract, cinchona extract, cucumber extract, apricot kernel extract, quince seed extract, gardenia extract, kumazasa extract, sophora flavescens extract, walnut shell extract, grapefruit extract, clematis extract, brown sugar extract, chlorella extract, mulberry extract, cinnamon extract, gentian extract, geranium extract, black tea extract, watercress extract, burdock extract, oil-soluble burdock extract, wheat germ extract, hydrolyzed wheat powder, rice bran extract, rice bran fermented extract, comfrey extract, saishi extract, saffron extract, soapwort extract, oil-soluble salvia extract, hawthorn extract, zanthoxylum extract, rehmannia extract, lithospermum extract, oil-soluble lithospermum extract, perilla extract, linden extract, oil-soluble linden extract, meadowsweet extract, peony extract, columbine extract, ginger extract, oil-soluble ginger extract, ginger tincture, calamus root extract, birch extract, oil-soluble birch extract, birch sap, honeysuckle extract, horsetail extract, oil-soluble horsetail extract, scordinin, ste Beer extract, English ivy extract, Hawthorn extract, Elderberry extract, Juniper extract, Yarrow extract, Oil-soluble Yarrow extract, Peppermint extract, Sage extract, Oil-soluble Sage extract, Sage water, Mallow extract, Celery extract, Cnidium officinalis extract, Cnidium officinalis water, Swertia japonica extract, Soybean extract, Chinese laurel extract, Thyme extract, Tea extract, Tea distillate, Tea fruit extract, Clove extract, Citrus aurantium extract, Camellia extract, Centella asiatica extract, Oil-soluble te Walnut extract, Duke extract, Terminalia extract, Capsicum tincture, Angelica extract, oil-soluble Angelica extract, Angelica water, Calendula extract, oil-soluble Calendula extract, soy milk powder, Peach kernel extract, Spruce extract, Houttuynia cordata extract, Tomato extract, Tormentilla extract, Natto extract, Carrot extract, oil-soluble carrot extract, Garlic extract, Wild rose extract, oil-soluble Wild rose extract, Bakuga extract, Bakuga root extract, Bakumondou extract, Parsley extract, Barley leaf juice concentrate, Distilled peppermint water, Hamame Squirrel water, Hamamelis extract, Rose extract, Parietaria extract, Scutellaria extract, Loquat leaf extract, Oil-soluble Loquat leaf extract, Coltsfoot extract, Poria columbine extract, Butcher's broom extract, Butcher's broom extract powder, Grape extract, Grape leaf extract, Grape water, Hayflower extract, Loofah extract, Loofah water, Safflower extract, Oil-soluble Lily extract, Lily water, Peony extract, Hop extract, Oil-soluble hop extract, Pine extract, Milk thistle extract, Horse chestnut extract, Oil-soluble Horse chestnut extract, Examples of such extracts include black jasmine extract, melissa extract, melilot extract, peach leaf extract, oil-soluble peach leaf extract, bean sprout extract, cornflower extract, cornflower water, eucalyptus extract, saxifrage extract, lily extract, coix seed extract, oil-soluble coix seed extract, mugwort extract, mugwort water, lavender extract, lavender water, apple extract, lychee extract, lettuce extract, lemon extract, astragalus extract, rose water, rosemary extract, oil-soluble rosemary extract, Roman chamomile extract, and burnet extract. These may be used alone or in combination of two or more.

The cleaning adjuvant may be any one known in the art, such as carbonates, soapberry extract, etc. These may be used alone or in combination of two or more.
As the preservative, any preservative known in the art may be used, and examples thereof include phenoxyethanol, benzoic acid or a salt thereof, sorbic acid or a salt thereof, dehydroacetic acid or a salt thereof, paraoxybenzoic acid ester, benzalkonium chloride, hinokitiol, etc. These may be used alone or in combination of two or more.

In one embodiment, the liquid detergent composition of the present invention does not contain a cellulose derivative, or if it does contain a cellulose derivative, the content thereof is preferably less than 0.01% by mass based on the entire composition.

In one embodiment, the liquid detergent composition of the present invention does not contain polyoxyethylene alkyl glycoside, or if it contains polyoxyethylene alkyl glycoside, the content is preferably less than 0.001% by mass based on the entire composition.

In one embodiment, the liquid detergent composition of the present invention does not contain a clay mineral, or if it contains a clay mineral, the content of the clay mineral is preferably less than 2.5 mass% based on the total composition. Examples of clay minerals include sodium montmorillonite and hectorite.

In one embodiment, the liquid cleaning composition of the present invention does not contain polyoxypropylene fatty acid isopropanolamide.

The liquid detergent composition of the present invention may be colorless or may be colored by incorporating any colorant known in the art. This can be changed as appropriate depending on the product design of the detergent composition.

It is preferable that all of the components of the liquid cleaning composition of the present invention form a homogeneous phase and are transparent. If some of the components separate from the continuous phase and float, this will cause cloudiness, which is undesirable from the viewpoint of aesthetics.

The liquid detergent composition of the present invention may be composed only of naturally derived materials, or may be composed by blending naturally derived materials with synthetic materials. When composed only of naturally derived materials, it is possible to provide a liquid detergent composition that is highly palatable to consumers who do not like synthetic chemicals.

The liquid detergent composition of the present invention can be suitably used as a skin cleaner such as hand soap, body soap, shampoo, or face wash, or as a cleaner such as dishwashing detergent or laundry detergent.

The liquid cleaning composition of the present invention can be produced by blending the specified components in the specified amounts and mixing them uniformly. The mixing means can be any known means in the art, and the mixing conditions can be set appropriately, provided that the composition is homogeneous.

The present invention will be explained in more detail below with reference to examples, but the scope of the present invention is not limited to the description of these examples.

Example 1
The fatty acid, water, and potassium hydroxide in the amounts shown in Table 1 were mixed, and an appropriate amount of an aqueous citric acid solution was added to adjust the pH to 9.5 to 10.5. Sodium pyrrolidonecarboxylate (AJIDEW (registered trademark) NL-50, manufactured by Ajinomoto Co., Inc.: 50% aqueous solution) in the amount shown in Table 1 was then added and mixed to prepare a cleaning composition sample. In Table 1, the "remainder" of the water content means the amount which, when combined with the contents of other components constituting the cleaning composition sample, amounts to 100% by mass.
100 g of the prepared sample was placed in a 100 ml polypropylene container and allowed to stand in a thermostatic chamber at 50° C. for one week, after which the odor and color were evaluated according to the following procedure.

Odor evaluation: The odor evaluation was carried out by a panel of five experts who scored the oxidative deterioration odor of the samples on a seven-point scale from 1 to 7. In the evaluation, the expert panel agreed on the standard criteria for how much the deterioration odor should be strengthened to raise the score and how much the deterioration odor should be improved to lower the score.
1 point: no deterioration odor 2 points: very weak deterioration odor 3 points: some deterioration odor 4 points: some deterioration odor 5 points: some strong deterioration odor 6 points: very strong deterioration odor 7 points: very strong deterioration odor Furthermore, the average score of the five expert panelists was calculated for each sample and evaluated according to the following criteria. The results are shown in Table 1.
◎: Average score of 2 points or less 〇: Average score of 2 points or more to 3 points or less △: Average score of 3 points or more to 4 points or less ×: Average score of 4 points or more

Color Tone Evaluation Color tone was evaluated by measuring the Δb* value of each sample using a special cell with a color difference meter CR-400 (manufactured by Konica Minolta, Inc.), determining the difference from the Δb* value immediately after preparation of Comparative Example 1 in Table 1 described below, and evaluating according to the following criteria. Comparative Example 1 is a transparent sample that does not contain sodium pyrrolidone carboxylate. The results are shown in Table 1.
◎: Difference is 2.0 or less. 〇: Difference is more than 2.0 to 3.0 or less. △: Difference is more than 3.0 to 6.0 or less. ×: Difference is more than 6.0.

Examples 2 to 9 and Comparative Examples 1 to 4
Using the components shown in Table 1, detergent composition samples were prepared in the same manner as in Example 1. When tocopherol was added, the tocopherol was dispersed in glycerin and added to the mixture after the pH adjustment. The odor and color of the prepared samples were evaluated in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 1, which does not contain sodium pyrrolidone carboxylate, produced a transparent, liquid cleaning composition that foamed well when used, and was confirmed to have no problems with suitability for use as a cleaning agent. However, an odor evaluation revealed that a deterioration odor occurred over time.

All of Examples 1 to 9, which contained sodium pyrrolidone carboxylate, produced transparent, liquid cleaning compositions that foamed well when used, and were confirmed to be suitable for use as cleaning agents. No deterioration over time was observed in either the odor or color evaluations, even in the harsh environment of 50°C.

Comparative Example 2, which uses Example 1 as a reference and uses tocopherol and glycerin as its solvent instead of sodium pyrrolidone carboxylate, showed an unacceptable change in color over time in the color evaluation. Tocopherol is a naturally occurring antioxidant, but it turns red when oxidized, which is thought to have been the cause of the color change. On the other hand, Example 2, which uses sodium pyrrolidone carboxylate in addition to Comparative Example 2, showed no change in color in the color evaluation, even though it contains tocopherol.

Comparative Example 4, which had a low content of fatty acid potassium, was very difficult to foam when used as a cleaning agent, and was poor in suitability for use.
In Comparative Example 3, in which the content of fatty acid potassium was high, the composition after preparation was solid rather than liquid, and a liquid detergent composition could not be prepared. No evaluation of odor or color tone was performed.

With reference to Example 1, Examples 6, 8 and 9 were prepared by changing the type and amount of fatty acid constituting the fatty acid potassium, and it was confirmed that transparent and liquid detergent compositions were obtained, which foamed well when used and had no problem in suitability for use as a detergent.
In Example 7, which was prepared by blending tocopherol with glycerin as a solvent for tocopherol in comparison with Example 6, no change in color tone was observed over time in the color tone evaluation.

Examples 10 to 19 and Comparative Examples 5 to 14
Using the components shown in Table 2 or Table 3, detergent composition samples were prepared in the same manner as in Example 1. In Tables 2 and 3, the "balance" of the water content means the amount that, when combined with the contents of other components constituting the detergent composition sample, amounts to 100 mass%.
The odor and color of the prepared samples were evaluated in the same manner as in Example 1. The results are shown in Tables 2 and 3.

In Examples 10 to 19, in which the fatty acid potassium content was varied and sodium pyrrolidone carboxylate was added, a transparent liquid detergent composition was obtained, which foamed well when used and was confirmed to have no problem in suitability for use as a detergent. No deterioration over time was observed in either the odor evaluation or the color evaluation, even in the harsh environment of 50°C.
In Comparative Examples 5 to 14, which had a high content of sodium pyrrolidone carboxylate among various fatty acid potassium contents, the liquid phase separated and floated on the liquid surface, and the appearance was cloudy. No evaluation of odor or color tone was performed.

Based on the results of Examples 10 to 19, the correlation between the fatty acid potassium content and the upper limit of the pyrrolidone carboxylate sodium content was approximated to a linear equation. The results are shown in FIG.
All of the samples in Examples 10 to 19 are suitable for use as liquid detergents, and are suppressed in terms of color change over time and the generation of a deterioration odor. On the other hand, all of the samples in Comparative Examples 5 to 14 are unfavorable in terms of the properties as liquid detergents. For various fatty acid potassium contents, it is presumed that samples suitable as liquid detergents, similar to those in Examples 10 to 19, can be obtained when the sodium pyrrolidone carboxylate content is within the upper limit range of the values in Examples 10 to 19.

From the results of Examples 10 to 19, as shown in FIG. 1 , it can be seen that when the content of fatty acid potassium is x [mass %] and the upper limit of the content of sodium pyrrolidonecarboxylate is y [mass %], the following formula (1) or formula (2) is satisfied depending on the content of fatty acid potassium.
(1) When x is 3 mass% or more and 20 mass% or less, y = 0.4x + 2.25
(2) When x is greater than 20% by mass and less than 36% by mass, y = -0.17x + 13.5

The liquid detergent composition of the present invention is highly industrially applicable because it can suppress color changes and the generation of odors caused by deterioration over time and can be used as a skin cleaner such as hand soap, body soap, shampoo, and face wash, as well as a cleaner such as dishwashing detergent and laundry detergent.

Claims (5)

A liquid cleaning composition comprising:
The composition contains, based on the entire composition, 10 to 35 mass% of an alkali metal salt of a fatty acid including an unsaturated fatty acid, and 0.01 to 10.3 mass% of one or more types selected from the group consisting of pyrrolidone carboxylic acid and salts thereof. A liquid cleaning composition comprising:
The composition contains, based on the entire composition, 3 to 36% by mass of an alkali metal salt of a fatty acid, including a saturated fatty acid and an unsaturated fatty acid, and 0.01 to 10.3% by mass of one or more selected from the group consisting of pyrrolidone carboxylic acid and salts thereof ;
The composition , wherein the saturated fatty acid comprises at least one selected from the group consisting of caprylic acid and capric acid . The liquid cleaning agent composition according to claim 1 or 2, which satisfies the following formula (1) or (2) when the content of the alkali metal salt of the fatty acid is x [% by mass] and the upper limit of the content of the one or more selected from the group consisting of pyrrolidone carboxylic acid and salts thereof is y [% by mass].
(1) When x is 3 mass% or more and 20 mass% or less, y = 0.4x + 2.25
(2) When x is greater than 20% by mass and less than 36% by mass, y = -0.17x + 13.5 The liquid detergent composition according to any one of claims 1 to 3, wherein the unsaturated fatty acid is at least one selected from the group consisting of oleic acid, linoleic acid, linolenic acid, palmitoleic acid, eicosenoic acid, and erucic acid. The liquid detergent composition according to any one of claims 1 to 4, wherein the molar ratio of the sodium salt to the potassium salt in the alkali metal salt of the fatty acid is 0:10 to 4:6.

Images