JP7701965B1 - Liquid cleaning composition - Google Patents

Abstract

The present invention provides a detergent composition that is less irritating to the skin, has good cleaning and rinsing properties, and has excellent bactericidal and viral inactivating effects even in the presence of organic soil.
[Solution] The present invention provides an alkaline liquid cleanser composition for skin which contains an alkyltrimethylammonium salt as a component (A-α), an alkyldimethylbenzylammonium salt as a component (A-β), a pH adjuster as a component (B), at least one selected from a nonionic surfactant and an amphoteric surfactant as a component (C), a polyhydric alcohol as a component (D), and water as a component (E), wherein the total amount of the components (A-α) and (A-β) is less than 0.6 mass%, the mass ratio (A-α)/(A-β) of the mass of the component (A-α) to the mass of the component (A-β) is 0.01 or more and less than 1, and the pH at 25°C is 8.0 or more and 12.0 or less.
[Selection diagram] None

Description

The present invention relates to an alkaline liquid detergent composition for skin. More specifically, the present invention relates to a detergent composition that is mainly used for washing hands and fingers, has low skin irritation, good cleaning and rinsing properties, and has excellent bactericidal and viral inactivating effects even in the presence of organic soils.

Traditionally, various methods have been used to wash and sterilize the hands of employees in food-related industries, such as meat and seafood processing and restaurant kitchens, as well as doctors, nurses, caregivers, and patients in hospitals and public health centers. The most common method is to first thoroughly wash the hands with a hand cleaner, and then sterilize the hands by immersing them in a hand disinfectant or spraying them with a disinfectant. These methods can be said to be effective when carried out faithfully according to the washing and sterilization manuals. However, there is a problem that if the hands are not washed sufficiently, the sterilizing power of the subsequent sterilization treatment is extremely reduced, and microorganisms that cause food poisoning may be brought into the workplace.

In recent years, the number of food poisoning cases and patients caused by norovirus has been increasing, and its high infectiousness has made it a major problem. Food poisoning caused by norovirus is not only caused by eating bivalve mollusks such as oysters, but also by secondary infection caused by contact with human feces and vomit, or by eating food contaminated by a cook infected with norovirus.

To prevent the introduction of food poisoning bacteria and secondary contamination by norovirus, thorough hand washing is required, and it is important that food production and cooking staff not bring microorganisms or viruses into the workplace.

Furthermore, it is generally known that the bactericidal effect of bactericides and other disinfectants is reduced in the presence of organic soil. Food manufacturing workers and cooks may become contaminated with organic soil derived from food, which may make it difficult for hand cleaners to exert their bactericidal and virus inactivating effects. For this reason, hand cleaners are required to be able to exert their bactericidal and virus inactivating effects even in the presence of organic soil.

Conventional detergents used for washing hands and fingers include a liquid detergent composition containing a fatty acid, an alkylaminocarboxylic acid type amphoteric surfactant, and a chelating agent and having a pH of 9.5 to 11 (Patent Document 1); a detergent composition containing an anionic surfactant having a specific structure as component (A), a glyceryl ether having a hydrocarbon group having 4 to 22 carbon atoms as component (B), at least one bactericide selected from the group consisting of triclosan, isopropylmethylphenol, and parachlorometaxylenol as component (C), an alkyl glycoside as component (D), and a saturated monohydric alcohol having 1 to 3 carbon atoms as component (E), in which the mass ratio of component (B) to component (E) is (B and a liquid skin cleanser composition comprising a quaternary ammonium salt surfactant as component (A), a pH adjuster as component (B), at least one surfactant selected from a nonionic surfactant and an amphoteric surfactant as component (C), water as component (D), and a polyhydric alcohol as component (E), wherein the mass ratio of component (A) to component (B), in terms of (A)/(B), is 0.002 or more and 100 or less, the mass ratio of component (A) to component (E), in terms of (A)/(E), is 0.001 or more and 1 or less, and the pH at 25° C. is 8.1 or more and 12.0 or less (Patent Document 4).
Furthermore, as a technology relating to a virus inactivation effect, there is mentioned an antiviral detergent composition which contains a quaternary ammonium salt, a nonionic surfactant and/or an amphoteric surfactant, and an alkaline agent and has a pH of 11 or more at 25° C. (Patent Document 3).

International Publication No. 2013/141118 JP 2020-026407 A JP 2019-052118 A Patent No. 6860734

The liquid detergent composition of Patent Document 1 has a certain degree of cleaning ability because its pH is in the alkaline range, but the bactericidal effect is insufficient and no virus inactivation effect is obtained. The skin detergent composition of Patent Document 2 has a bactericidal effect and cleaning ability, but has a neutral pH and therefore no virus inactivation effect is obtained. The antiviral detergent composition of Patent Document 3 can inactivate viruses and clean objects having hard surfaces such as countertops, refrigerators, toilets, and floors by wiping them with the antiviral detergent impregnated into a nonwoven fabric or spraying them with a spray and then rinsing with water, but it is highly irritating to the skin, so workers must wear gloves when working. The liquid detergent composition of Patent Document 4 can be used to wash hands and fingers, is less irritating to the skin, and has excellent cleaning ability, bactericidal effect, and virus inactivation effect, but there is room for improvement in the bactericidal effect and virus inactivation effect in the presence of organic dirt.

The present invention was discovered to solve the above problems. That is, the object of the present invention is to provide a cleaning composition that is less irritating to the skin, has good cleaning and rinsing properties, and has excellent bactericidal and viral inactivating effects even in the presence of organic soils.

In order to solve the above problems, the present inventors conducted extensive research and discovered that a composition containing an alkyltrimethylammonium salt as the (A-α) component, an alkyldimethylbenzylammonium salt as the (A-β) component, a pH adjuster as the (B) component, at least one selected from a nonionic surfactant and an amphoteric surfactant as the (C) component, a polyhydric alcohol as the (D) component, and water as the (E) component, and further containing the (A-α) component and the (A-β) component in a specific total amount range, and having the (A-α) component and the (A-β) component in a specific ratio range, is low irritation to the skin, has excellent cleansing properties, and provides good bactericidal and viral inactivation effects even in the presence of organic dirt, thus completing the present invention.

That is, the alkaline liquid cleanser composition for skin of the present invention comprises an alkyltrimethylammonium salt as component (A-α), an alkyldimethylbenzylammonium salt as component (A-β) , a pH adjuster consisting of a combination of an alkali metal hydroxide and/or an alkanolamine with at least one selected from an alkali metal carbonate, an alkali metal phosphate, and an organic acid salt as component (B) , 0.1 mass % or more and 6 mass % or less of at least one selected from a nonionic surfactant and an amphoteric surfactant as component (C) , and ethylene glycol, diethylene glycol, triethylene glycol, ... and water as component (E), wherein the total amount of the components (A-α) and (A-β) is 0.06% by mass or more and 0.5% by mass or less, the mass ratio (A-α)/(A-β) of the mass of the component (A-α) to the mass of the component (A-β) is 0.06 or more and 0.75 or less , and the pH at 25° C. is 8.0 or more and 12.0 or less.

In the present invention, the mass ratio of the mass of the component (C) to the mass of the component (A), i.e., component (C)/component (A), is preferably 0.1 or more and 150 or less .

The present invention also preferably contains, as component (C), at least one selected from polyoxyalkylene alkyl ethers, alkyl glucosides including alkyl polyglucosides, alkyl betaine-type amphoteric surfactants, alkyl imidazolinium betaine-type amphoteric surfactants, alkyl amino (mono- or di-)propionates, and alkyl dimethyl amine oxides.

In the present invention, it is preferable that the component (D) contains at least one member selected from ethylene glycol, polyethylene glycol, propylene glycol, butylene glycol, 1,5-pentanediol, hexylene glycol, glycerin, and sorbitol.
In the present invention, the above-mentioned alkaline liquid cleanser composition for skin is preferably a liquid cleanser for hands.

The alkaline liquid skin cleaner composition of the present invention has excellent bactericidal and viral inactivating effects in the presence of organic soil.

The alkaline liquid skin cleanser composition of the present invention contains an alkyl trimethyl ammonium salt as the component (A-α), an alkyl dimethyl benzyl ammonium salt as the component (A-β), a pH adjuster as the component (B), at least one selected from a nonionic surfactant and an amphoteric surfactant as the component (C), a polyhydric alcohol as the component (D), and water as the component (E), and is characterized in that the total amount of the components (A-α) and (A-β) is less than 0.6% by mass, and the mass ratio (A-α)/(A-β) of the mass of the component (A-α) to the mass of the component (A-β) is 0.01 or more and less than 1.

(A-α) Alkyltrimethylammonium Salt The alkyltrimethylammonium salt used in the present invention is represented by the general formula ([R ¹ N(CH ₃ ) ₃ ] ⁺ ·X ^- ). Here, R ¹ is a linear or branched alkyl group having 8 to 22 carbon atoms, and X is a halogen atom. Examples of R ¹ include alkyl groups such as octyl, nonyl, decyl, undecyl, lauryl, tridecyl, myristyl, pentadecyl, heptadecyl, stearyl, nonadecyl, and eicosyl.
Among these, alkyl groups having 10 to 18 carbon atoms are preferred, alkyl groups having 12 to 18 carbon atoms are more preferred, alkyl groups having 14 to 18 carbon atoms are even more preferred, and alkyl groups having 16 carbon atoms are most preferred.

X represents a group that forms a counter ion, and examples of such groups include halogen atoms and alkyl sulfates. Of these, halogen atoms, particularly chlorine and bromine atoms, are preferred.

Specific examples of alkyltrimethylammonium salts include lauryltrimethylammonium chloride, hexadecyltrimethylammonium chloride, stearyltrimethylammonium chloride, coconut alkyltrimethylammonium chloride, alkyl (C14-C18)trimethylammonium chloride, alkyl (C16-C18)trimethylammonium chloride, behenyltrimethylammonium chloride, hexadecyltrimethylammonium bromide, and steartrimethylammonium bromide. Among these, lauryl trimethyl ammonium chloride, hexadecyl trimethyl ammonium chloride, stearyl trimethyl ammonium chloride, coconut alkyl trimethyl ammonium chloride, alkyl (C14-C18) trimethyl ammonium chloride, alkyl (C16-C18) trimethyl ammonium chloride, hexadecyl trimethyl ammonium bromide, and steartrimethyl ammonium bromide are preferred, lauryl trimethyl ammonium chloride, hexadecyl trimethyl ammonium chloride, stearyl trimethyl ammonium chloride, alkyl (C14-C18) trimethyl ammonium chloride, alkyl (C16-C18) trimethyl ammonium chloride, hexadecyl trimethyl ammonium bromide, and steartrimethyl ammonium bromide are more preferred, and hexadecyl trimethyl ammonium chloride and hexadecyl trimethyl ammonium bromide are even more preferred.

(A-β) Alkyldimethylbenzylammonium salt The alkyldimethylbenzylammonium salt used in the present invention is represented by the general formula ([C ₆ H ₅ CH ₂ N(CH ₃ ) ₂ R ² ] ⁺ ·X ^- ). Here, R ² represents a linear or branched alkyl group having 8 to 18 carbon atoms. Examples of R ² include octyl, nonyl, decyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, and octadecyl groups. Among these, it is preferable that R ² has 12 to 16 carbon atoms.

X represents a group that forms a counter ion, and examples of such groups include halogen atoms and alkyl sulfates. Of these, halogen atoms, and particularly chlorine atoms, are preferred.

Examples of alkyl dimethyl benzyl ammonium salts include alkyl (C12-16) dimethyl benzyl ammonium chloride, octyl dimethyl benzyl ammonium chloride, decyl dimethyl benzyl ammonium chloride, stearyl dimethyl benzyl ammonium chloride, etc. Among these, alkyl (C12-16) dimethyl benzyl ammonium chloride is preferred.

The (A) component contributes to the bactericidal power and virus inactivation of the alkaline liquid skin cleaner composition of the present invention. Therefore, if the blending amount of the (A-α) component and the (A-β) component is too small, the bactericidal power or virus inactivation effect of the alkaline liquid skin cleaner composition may be insufficient. On the other hand, if the blending amount of the (A-α) component and the (A-β) component is too large, the skin irritation may become strong, and the rinsing property and storage stability may also be undesirably affected.
From such a viewpoint, the concentration of the total amount of the component (A-α) and the component (A-β) in the alkaline liquid skin cleanser composition of the present invention is less than 0.6 mass%, preferably from 0.01 mass% to less than 0.6 mass%, more preferably from 0.03 mass% to 0.57 mass%, even more preferably from 0.06 mass% to 0.54 mass%, and particularly preferably from 0.10 mass% to 0.50 mass%.

The alkaline liquid skin cleanser composition of the present invention may contain quaternary ammonium salt surfactants other than the component (A-α) and the component (A-β) (hereinafter referred to as "other quaternary ammonium salts") within the range that does not impair the effects of the present invention, but the total amount of the component (A-α) and the component (A-β) is preferably at least 80 mass%, more preferably at least 90 mass%, and particularly preferably at least 95 mass%, relative to the total amount of the component (A-α), the component (A-β), and the other quaternary ammonium salts. In another embodiment, the alkaline liquid skin cleanser composition of the present invention does not contain other quaternary ammonium salts.
In addition, the total amount of the component (A-α), the component (A-β) and other quaternary ammonium salts is preferably less than 0.6 mass% based on the total amount of the alkaline liquid skin cleanser composition.

From the viewpoint of bactericidal power and virus inactivation effect, the (A-α) component used in the present invention is preferably 0.005% by mass or more and 0.3% by mass or less, more preferably 0.008% by mass or more and 0.27% by mass or less, even more preferably 0.01% by mass or more and 0.24% by mass or less, and particularly preferably 0.01% by mass or more and 0.15% by mass or less, based on the total amount of the alkaline liquid skin cleanser composition of the present invention.

The (A-β) component used in the present invention is preferably 0.005% by mass or more and 0.59% by mass or less, more preferably 0.01% by mass or more and 0.5% by mass or less, even more preferably 0.05% by mass or more and 0.3% by mass or less, and particularly preferably 0.1% by mass or more and 0.2% by mass or less, based on the total amount of the alkaline liquid skin cleanser composition of the present invention. If the (A-β) component is less than 0.005% by mass, sufficient bactericidal power and virus inactivation effect cannot be obtained. Furthermore, if it is more than 0.59% by mass, skin irritation may be strong and rinsing properties and storage stability may be reduced.

In the alkaline liquid skin cleanser composition of the present invention, the mass ratio (A-α)/(A-β) of the mass of the (A-α) component to the mass of the (A-β) component must be 0.01 or more and less than 1. This value is preferably 0.02 or more and 0.9 or less, more preferably 0.06 or more and 0.8 or less, and particularly preferably 0.1 or more and 0.75 or less. If this value is less than 0.01, a decrease in bactericidal power is observed, and if it is 1.0 or more, a decrease in the virus inactivation effect is observed.

Here, viruses include enveloped viruses, which are viruses that have an envelope, and non-enveloped viruses, which are viruses that do not have an envelope.

Enveloped viruses include, but are not limited to, human herpesvirus, vaccinia virus, influenza virus, SARS coronavirus, MERS coronavirus, SARS-CoV-2, respiratory syncytial virus, mumps virus, Lassa virus, dengue virus, rubella virus, human immunodeficiency virus, measles virus, hepatitis B virus, hepatitis C virus, Ebola virus, yellow fever virus, and Japanese encephalitis virus.

Non-enveloped viruses include, but are not limited to, norovirus, poliovirus, echovirus, rhinovirus, astrovirus, rotavirus, coxsackievirus, enterovirus, sapovirus, adenovirus, human parvovirus B19 virus, human papillomavirus, hepatitis A virus, and hepatitis E virus.

(B) pH adjuster The (B) component is a pH adjuster for adjusting the pH of the alkaline liquid skin cleaner composition of the present invention. The liquid cleaner composition of the present invention is preferably adjusted to a pH range of 8.0 or more and 12.0 or less by the (B) component, taking into consideration the blending amounts of other components. A typical alkaline cleaner is highly irritating to the skin and is avoided from being used directly on the hands and fingers, but the present invention is alkaline, but by blending the (A) component and the (C) component, it is possible to exert high cleaning power, bactericidal power and virus inactivation effect (hereinafter, these are also referred to as cleaning properties, etc.) while suppressing irritation to the skin.

From the viewpoint of exerting more sufficient cleaning properties, bactericidal power, and virus inactivation effects, the above pH is preferably 9 or more, and more preferably 9.5 or more. Furthermore, from the viewpoint of providing a cleaning agent with less skin irritation, the above pH is preferably 11.5 or less, more preferably 11 or less, and particularly preferably less than 11.

The pH adjuster can be selected from compounds capable of adjusting the pH of the liquid detergent composition without impairing the effects of the present invention. For example, the pH adjuster can be any one or combination selected from alkali metal hydroxides, alkali metal silicates, alkanolamines, alkali metal carbonates, alkali metal phosphates, and organic acid salts.

The alkali metal hydroxide includes, for example, sodium hydroxide, potassium hydroxide, and the like.
Examples of alkali metal silicates include sodium orthosilicate, potassium orthosilicate, sodium metasilicate, potassium metasilicate, No. 1 sodium silicate, No. 2 sodium silicate, No. 3 sodium silicate, potassium A silicate, potassium B silicate, and potassium C silicate.
The alkanolamine may, for example, be monoethanolamine, diethanolamine, or triethanolamine.
Examples of the alkali metal carbonate include sodium carbonate, potassium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, sodium sesquicarbonate, potassium sesquicarbonate, sodium percarbonate, and potassium percarbonate.
Examples of the alkali metal phosphate include sodium phosphate, potassium phosphate, sodium dihydrogen phosphate, potassium dihydrogen phosphate, disodium hydrogen phosphate, and dipotassium hydrogen phosphate.
Examples of organic acid salts include sodium citrate, potassium citrate, trisodium citrate, tripotassium citrate, sodium gluconate, potassium gluconate, sodium lactate, potassium lactate, sodium acetate, and potassium acetate.

From the viewpoint of cleaning properties, the component (B) is preferably an alkali metal hydroxide or an alkanolamine.
From the viewpoint of effective virus inactivation for objects to be washed that have organic soiling, it is preferable to use an alkali metal hydroxide and/or an alkanolamine in combination with at least one selected from alkali metal carbonates, alkali metal phosphates, and organic acid salts. This is presumably because the buffering action of the carbonates, phosphates, or organic acid salts prevents a drop in pH even when soiling is present, thereby providing an excellent virus inactivation effect.

The proportion of component (B) relative to the total amount of the alkaline liquid skin cleaner composition of the present invention is preferably 0.05% by mass or more and 5.0% by mass or less, more preferably 0.1% by mass or more and 4.0% by mass or less, and particularly preferably 0.3% by mass or more and 3.0% by mass or less. If it is less than 0.05% by mass, the bactericidal power and virus inactivation effect may be insufficient, and if it is more than 5% by mass, skin irritation may increase and storage stability may decrease.

When a general liquid detergent composition is brought into contact with an object to be cleaned that has organic dirt or the like attached thereto, the pH of the liquid detergent composition may be significantly reduced. As a result, the cleaning properties and the like are reduced, and the object to be cleaned is not sufficiently cleaned and sterilized. In addition, there is a problem that sufficient sterilization is not achieved even if a disinfectant or the like is sprayed on an object to be cleaned that has not been completely cleaned and sterilized. In contrast, the liquid detergent composition of the present invention has a pH adjusted to a predetermined range by the pH adjuster (B), so that even when it comes into contact with organic dirt, it is easy to maintain its alkalinity, and as a result, it is easy to maintain high cleaning properties and the like.
Weak bases such as sodium bicarbonate, potassium bicarbonate, sodium dihydrogen phosphate, potassium dihydrogen phosphate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, trisodium citrate, and tripotassium citrate have a buffering effect that prevents the pH of the liquid detergent composition from decreasing even when it comes into contact with dirt, thereby maintaining high cleaning properties, etc., and are able to effectively inactivate viruses on objects having organic dirt attached thereto.

The alkaline liquid skin cleanser composition of the present invention contains at least one selected from the group consisting of nonionic surfactants and amphoteric surfactants as component (C). These surfactants contribute to realizing good cleansing properties while suppressing irritation to the skin, and also contribute to good foaming during use.

Examples of the nonionic surfactant which is component (C) above include aliphatic alkanolamides, polyoxyalkylene alkyl ethers, polyoxyethylene fatty acid esters, polyoxyethylene polyoxypropylene glycols, sucrose fatty acid esters, monoglycerin fatty acid esters, polyglycerin fatty acid esters, sorbitan fatty acid esters, alkylene oxide adducts of sorbitan fatty acid esters, and alkyl glucosides.
The number of carbon atoms in the alkyl group is not particularly limited, but is preferably 6 or more and 14 or less. More specific examples include octyl glucoside, decyl glucoside, and lauryl glucoside.

Examples of the amphoteric surfactant that is component (C) above include betaine-type amphoteric surfactants, amino acid-type amphoteric surfactants, and amine oxide-type amphoteric surfactants.

In the present invention, the betaine-type amphoteric surfactant refers to a surfactant that has a betaine in its molecular structure and thus exhibits amphiphilicity. Here, betaine refers to an intramolecular salt that has a positive charge and a negative charge at non-adjacent positions in the same molecule.
The betaine type amphoteric surfactants include alkyl betaine type amphoteric surfactants, alkyl imidazolinium betaine type amphoteric surfactants, and fatty acid amidopropyl betaine type amphoteric surfactants.

Examples of the alkyl betaine type amphoteric surfactant include alkyl dimethyl amino acetate betaine, alkyl dimethyl amino sulfobetaine, alkyl hydroxy sulfobetaine, etc. The number of carbon atoms in the alkyl group is not particularly limited, but is preferably 8 to 18, and more specifically, examples thereof include lauryl dimethyl amino acetate betaine, stearyl dimethyl amino acetate betaine, etc.
Examples of the alkyl imidazolinium betaine type amphoteric surfactant include 2-alkyl-N-carboxymethyl-N-hydroxyethyl imidazolinium betaine, 2-alkyl-N-carboxyethyl-N-hydroxyethyl imidazolinium betaine, etc. The number of carbon atoms in the alkyl group is not particularly limited, but is preferably 8 or more and 18 or less.
Examples of the alkylamidopropyl betaine type amphoteric surfactant include coconut oil fatty acid amidopropyl betaine, palm oil fatty acid amidopropyl betaine, lauric acid amidopropyl betaine, myristic acid amidopropyl betaine, ricinoleic acid amidopropyl betaine, etc. The number of carbon atoms in the alkyl group is not particularly limited, but is preferably 8 to 18.

In the present invention, examples of amino acid type amphoteric surfactants include alkylaminoethylglycine, alkyldiaminoethylglycine, glycine n-(3-aminopropyl) C10-16 derivatives, alkylpolyaminoethylglycine, carboxymethylglycine, alkylamino (mono- or di-)propionate, alkylaminodiacetate, etc. The number of carbon atoms in the alkyl group is not particularly limited, but is preferably 8 to 16. More specifically, dodecyldiaminoethylglycine, tetradecyldiaminoethylglycine, dodecyldiaminoethylglycine chloride, tetradecyldiaminoethylglycine chloride, sodium laurylpropionate, sodium laurylaminodipropionate, etc. can be mentioned.

In the present invention, examples of amine oxide type amphoteric surfactants include alkyl dimethylamine oxide, alkyl amidopropyl dimethylamine oxide, dihydroxyethyl alkylamine oxide, etc. The number of carbon atoms in the alkyl group is not particularly limited, but is preferably 8 to 18. More specifically, examples include octyl dimethylamine oxide, decyl dimethylamine oxide, lauryl dimethylamine oxide, myristyl dimethylamine oxide, coconut oil alkyl dimethylamine oxide, lauric acid amidopropyl dimethylamine oxide, dihydroxyethyl coconut oil alkyl amine oxide, etc.

From the viewpoint of providing a liquid detergent composition that exhibits more preferable foam retention and rinsing properties, it is preferable that the above-described component (C) contains at least one selected from polyoxyalkylene alkyl ethers such as polyoxyethylene alkyl ethers, alkyl glucosides, alkyl betaine-type amphoteric surfactants, alkyl imidazolinium betaine-type amphoteric surfactants, alkyl amino (mono- or di-)propionates, and alkyl dimethyl amine oxides, and it is more preferable that the component (C) contains at least one of alkyl glucosides including alkyl polyglucosides, alkyl betaine-type amphoteric surfactants, and alkyl imidazolinium betaine-type amphoteric surfactants.

The content of the nonionic surfactant or amphoteric surfactant (C) can be appropriately determined within a range that does not impair the effects of the present invention. The proportion of the (C) component in the total amount of the alkaline liquid detergent composition for skin is preferably 0.1 mass% or more and 8.0 mass% or less, more preferably 0.5 mass% or more and 6 mass% or less, and particularly preferably 1.0 mass% or more and 6 mass% or less.
If the amount of component (C) is less than 0.1% by mass, good foaming may not be obtained, whereas if it is more than 8.0% by mass, storage stability may decrease.

In the alkaline liquid skin cleanser composition of the present invention, the mass ratio (C)/(A) of the mass of component (C) to the mass of component (A) is preferably 0.1 or more and less than 150, more preferably 0.2 or more and 130 or less, and even more preferably 0.8 or more and 100 or less. By having this value fall within the above range, it is possible to achieve both good foaming and disinfecting power.

(D) Polyhydric alcohol The alkaline liquid skin cleanser composition of the present invention contains a polyhydric alcohol as component (D). By incorporating component (D), it is possible to further reduce the skin irritation of the alkaline liquid skin cleanser composition having a high pH.

Examples of the (D) component include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, 1,3-butylene glycol, 1,4-butanediol, 1,5-pentanediol, hexylene glycol, glycerin, polyglycerin, sorbitol, etc., among which ethylene glycol, polyethylene glycol, propylene glycol, butylene glycol, 1,5-pentanediol, hexylene glycol, glycerin, and sorbitol are preferred, with glycerin, propylene glycol, and polyethylene glycol being particularly preferred.

From the viewpoint of exerting a skin irritation suppression effect, the blending amount of the above-mentioned (D) component is preferably 0.1 mass % or more and 10 mass % or less, more preferably 0.5 mass % or more and 8 mass % or less, and particularly preferably 1 mass % or more and 6 mass % or less, based on the total amount of the alkaline liquid skin cleanser composition. If the concentration of the (D) component is less than 0.1 mass %, the skin irritation suppression effect may not be sufficient, and even if more than 10 mass % is blended, an effect commensurate with the blending amount will not be observed.

(E) Water The liquid detergent composition of the present invention contains water as component (E). The water of component (E) is not particularly limited, and tap water, softened water, pure water, RO water, ion-exchanged water, and distilled water can be used. Examples of tap water include tap water from Arakawa Ward, Tokyo (pH = 7.6, total alkalinity (calcium carbonate equivalent) 40.5 mg/L, German hardness 2.3° DH (including calcium hardness 1.7° DH and magnesium hardness 0.6° DH), chloride ions 21.9 mg/L, sodium and its compounds 15 mg/L, nitrate nitrogen and nitrite nitrogen 1.2 mg/L, fluorine and its compounds 0.1 mg/L, boron and its compounds 0.04 mg/L, total trihalomethanes 0.016 mg/L, residual chlorine 0.4 mg/L, organic matter (total organic carbon amount) 0.7 mg/L). The water (E) of the present invention constitutes the balance relative to the total amount of the above components (A) to (D), or the balance relative to the total amount of components (A) to (D) and other optional components.

The liquid detergent composition of the present invention may contain other ingredients commonly used in the art as necessary, provided that the effects of the present invention are not impaired. Examples of such components include fatty acids such as caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, behenic acid, coconut fatty acid, and salts thereof; metal corrosion inhibitors such as benzotriazole, tolyltriazole, benzothiazole, 1-hydroxyethylidene-1,1-diphosphonic acid, 2-phosphonobutane-1,2,4-tricarboxylic acid, and aminotrimethylenephosphonic acid; alcohol-based solvents such as ethanol, isopropanol, and phenoxyethanol; glycol ether-based solvents such as diethylene glycol monobutyl ether and dipropylene glycol monobutyl ether; chelating agents such as ethylenediaminetetraacetic acid, diethylenetriaminopentaacetic acid, triethylenetetraaminehexaacetic acid, methylglycine diacetic acid, and glutamic acid diacetic acid, and salts thereof; bactericides such as isopropylmethylphenol, triclosan, and triclocarban; thickeners such as xanthan gum; inorganic electrolytes such as sodium chloride; fragrances; and pigments. Of the above components, fatty acids may be preferably blended in terms of foam retention and rinsing properties, alcohol-based solvents in terms of bactericidal power, glycol ether-based solvents in terms of storage stability, and thickeners and inorganic electrolytes in terms of foam retention. When the above alcohol-based solvent is contained in the liquid detergent composition from the viewpoint of improving bactericidal power while suppressing skin irritation, the alcohol-based solvent is preferably contained in a range of, for example, 0.01% by mass to 1.0% by mass, more preferably 0.05% by mass to 0.8% by mass, and even more preferably 0.1% by mass to 0.6% by mass.

The alkaline liquid skin cleanser composition of the present invention is generally prepared by mixing and stirring each component when it is liquid, or by first dissolving solid components in water, followed by adding and stirring the other liquid components, but depending on the composition, there are no particular limitations on the order of addition and dissolution of each component, or on the manufacturing procedure such as heating/cooling as necessary.

The alkaline liquid skin cleaner composition of the present invention can be used by foaming the liquid cleaner composition in the palm of the hand or with a sponge, or it can be filled into a foaming container and used as a foamed cleaner extruded from the foaming container when used.

The alkaline liquid skin cleaner composition of the present invention is preferably used to clean human skin, and is more preferably used as a so-called hand soap for cleaning hands and fingers. The time for cleaning with the alkaline liquid skin cleaner composition of the present invention is not particularly limited, but from the viewpoint of more thoroughly cleaning hands and fingers, it is preferably 10 seconds or more and less than 90 seconds, and more preferably 20 seconds or more and less than 60 seconds.

The present invention will be described in detail below with reference to examples and comparative examples. The components used in the liquid detergent compositions of the examples and comparative examples are shown in Tables 1 to 7 below. The numerical values relating to the blending amounts shown in Tables 1 to 7 below are the ratio (mass %) of the pure content of each component to the liquid detergent composition.
It should be noted that Examples 1 to 22, 37, 38, and 40 are reference examples.

(A) Components A-α1: Hexadecyltrimethylammonium chloride A-α2: Stearyltrimethylammonium chloride A-α3: Lauryltrimethylammonium chloride A-α4: Alkyl (C14-C18) trimethylammonium chloride A-β: Alkyl (C12-C16) dimethylbenzylammonium chloride A-γ: Dialkyl (C10) methylhydroxyethylammonium propionate

(B) Components B-1: Potassium hydroxide B-2: Monoethanolamine B-3: Sodium hydrogen carbonate B-4: Sodium carbonate B-5: Trisodium citrate B-6: Disodium hydrogen phosphate B-7: Sodium dihydrogen phosphate

(C) Component C-1: Lauryl glucoside C-2: Lauryl amidopropyl betaine C-3: Sodium laurylaminodipropionate C-4: 2-alkyl (C8 to C18)-N-carboxyethyl-N-hydroxyethyl imidazolinium betaine C-5: Polyoxyethylene alkyl ether (having a straight-chain hydrocarbon group having 12 carbon atoms, the average number of moles of oxyethylene groups added is 7)
C-6: Lauryl dimethylamine oxide

(D) Component D-1: Glycerin
D-2: Propylene glycol D-3: Polyethylene glycol (weight average molecular weight 400)

(E) Component E-1: Ion-exchanged water

Other ingredients F-1: Disodium ethylenediaminetetraacetate F-2: Trisodium methylglycine diacetate F-3: Tetrasodium glutamate diacetate F-4: Sodium chloride F-5: Ethanol F-6: Phenoxyethanol

*1: Cleaning test <Test method>
The test was conducted once a day after work on 10 panelists who work in office and field jobs, using a wipe tester (Lucipac (registered trademark) PEN; manufactured by Kikkoman Corporation) in accordance with the instruction manual. One type of liquid detergent composition was used per day.
First, the cotton swab set in the body of the Lucipack PEN was removed, and both hands of each panelist were wiped with the cotton swab before hand washing, which was used as a wipe sample. The wipe sample was returned to the Lucipack PEN body and thoroughly immersed in a luminescence reagent in a measurement tube provided at the tip of the Lucipack PEN. Then, using a luminescence measurement device (Lumitester (registered trademark) PD-30; manufactured by Kikkoman Corporation), the Lucipack PEN was inserted into the measurement chamber of the Lumitester PD-30, and the ATP luminescence (RLU ₀ ) before hand washing was measured.

After preparing the wipe samples, each panelist took 1 mL of the liquid detergent composition on their hands, washed their hands for 30 seconds, rinsed them with tap water for 30 seconds, and then thoroughly drained the water to finish washing their hands.
After hand washing, the ATP luminescence ( _RLU1 ) of each panelist was measured in the same manner as above. Using the measured values of the ATP luminescence ( _RLU0 ) before hand washing and the ATP luminescence ( _RLU1 ) after hand washing, the cleaning rate by hand washing was calculated according to the following (Equation 1), the average cleaning rate of the 10 panelists was calculated, and the cleaning performance was evaluated according to the evaluation criteria described below.
(Formula 1)
Cleaning rate (%)=100− _RLU1 / _RLU0 ×100 (1)

<Evaluation criteria>
◎: Cleaning rate is 90% or more.
◯: cleaning rate is 75% or more but less than 90%.
△: cleaning rate is 60% or more but less than 75%.
×: cleaning rate is less than 60%.
The items were judged as practical with △, ○, and ◎.

*2: Bactericidal activity test against general bacteria <Test bacteria>
The test bacteria used were Escherichia coli (NBRC3972) and Staphylococcus aureus (NBRC12732). Each test bacteria was smeared on SCD agar medium (manufactured by Eiken Chemical Co., Ltd.), cultured at 37°C for 24 hours, and then the colonies were scraped off and diluted in sterilized phosphate-buffered saline to be used as a bacterial suspension.
<Test Method>
To 10 mL of each liquid detergent composition, 0.1 mL of each bacterial suspension was added to give a final concentration of 1.5 to 5.0 x 10 ⁸ (CFU/mL), and the mixture was allowed to come into contact at 25°C for 15 seconds, followed by adding a sterile neutralizing solution (SCDLP medium, manufactured by Eiken Chemical Co., Ltd.) and stirring thoroughly to give a test solution. In addition, to 10 mL of each liquid detergent composition containing 0.1 mass% yeast extract as a soiling agent, assuming organic soiling, 0.1 mL of each bacterial suspension was added to give a final concentration of 1.5 to 5.0 x 10 ⁸ (CFU/mL), followed by contact at 25°C for 30 seconds, followed by adding a sterile neutralizing solution (SCDLP medium, manufactured by Eiken Chemical Co., Ltd.) and stirring thoroughly to give a test solution. Each 1 mL of the mixture was mixed and solidified on SCD agar medium, and then cultured at 37°C for 2 days. After the cultivation, the viable cell count was measured, and the log reduction value was calculated from the difference with the initial cell count, and the bactericidal activity was evaluated according to the following criteria.

<Evaluation criteria>
The reduction in the number of bacteria for each species of bacteria was evaluated using a score as follows: 1 point: a reduction in the number of bacteria for which the Log reduction of the test bacteria is 5 or more; 2 points: a reduction in the number of bacteria for which the Log reduction of the test bacteria is 3 or more and less than 5; 3 points: a reduction in the number of bacteria for which the Log reduction of the test bacteria is 1 or more and less than 3; 4 points: a reduction in the number of bacteria for which the Log reduction of the test bacteria is less than 1.

The above evaluation scores were averaged for the two types of bacteria, and the bactericidal activity was evaluated according to the following criteria.
⊚: Average value is 1.0 or more and less than 1.5 points.
○: Average value is 1.5 points or more and less than 2.5 points.
△: Average value is 2.5 points or more and less than 3.5 points.
×: Average value is 3.5 or more.
The items were judged as practical with △, ○, and ◎.

*3: Virus inactivation test <Test method>
In a test tube, 0.9 mL of each liquid detergent composition was added to 0.1 mL of virus liquid adjusted to 10 ⁸ TCID ₅₀ /mL for each of the three types of viruses listed below, and mixed in a mixer to prepare a mixed liquid, which was then allowed to act at 25°C for 30 seconds.
In addition, to simulate organic soiling, 0.9 mL of each liquid detergent composition was placed in a test tube, and 0.1 mL of a virus solution containing 5% meat extract (manufactured by Nacalai Tesque) adjusted to 10 ⁸ TCID ₅₀ /mL for each of the following three types of viruses was added, mixed in a mixer to create a mixed solution, and allowed to act at 25°C for 30 seconds.
After the action, 0.1 mL of the above mixture was sampled and added to 9.9 mL of a stop solution (cell growth solution containing 2% sodium thiosulfate, 0.2% lecithin, and 1.5% polysorbate 80) to dilute 100-fold, and the action of the various squeezed solutions against the virus was stopped. This was used as a sample stock solution for measuring the virus infectivity titer in order to measure the infectivity titer. Similarly, a test was carried out using phosphate buffered saline (hereinafter sometimes abbreviated as PBS) instead of the squeezed solution, and this was used as a control.
The phosphate buffered saline was prepared by mixing four salts, namely, 8 g of sodium chloride, 0.2 g of potassium chloride, 1.44 g of disodium hydrogen phosphate, and 0.24 g of potassium dihydrogen phosphate, dissolving them in 900 mL of ultrapure water, adjusting the pH to 7.4 with hydrochloric acid, and then filling the solution to 1 L and sterilizing it in an autoclave.

Three types of viruses were used in the above test: feline calicivirus, mouse norovirus, and influenza virus.
Each sample stock solution for virus infectivity measurement was diluted 10- ^fold with PBS to prepare dilutions, and then 50 μL of each of the sample stock solution for virus infectivity measurement and the dilutions at each dilution step, and 50 μL of cell solution suspended in Dulbecco's modified Eagle's Medium (DMEM) containing 5% fetal bovine serum (FBS), were planted in a 96-well plate. Then, the cells were cultured for 4 days in a carbon dioxide incubator at 37° C. and 5% CO _2. After the culture, the presence or absence of CPE (cytopathic effect) due to virus growth was observed under an inverted microscope, and the virus infectivity (TCID ₅₀ /mL) was determined using the Reed-Muench method and evaluated according to the following criteria.

<Evaluation criteria>
The reduction in the virus infectivity for each virus was evaluated using a score as follows: 1 point: a reduction in virus infectivity of 4 or more; 2 points: a reduction in virus infectivity of 3 or more and less than 4; 3 points: a reduction in virus infectivity of 2 or more and less than 3; 4 points: a reduction in virus infectivity of less than 1. The reduction in the virus infectivity for each virus was evaluated using a score, and the average score for the three types of viruses was calculated, and the virus inactivation effect was evaluated according to the following criteria.

⊚: Average value is 1.0 or more and less than 1.5 points.
○: Average value is 1.5 points or more and less than 2.5 points.
△: Average value is 2.5 points or more and less than 3.5 points.
×: Average value is 3.5 or more.
The items were judged as practical with △, ○, and ◎.

*4: Foam retention test <Test method>
In this test, each liquid detergent composition was foamed at 25°C by the Ross-Miles method (JIS K 3362), and the foam height was measured at the start of measurement and after 5 minutes. The foam retention rate was calculated from the foam height after 5 minutes ( _F1 ) relative to the foam height at the start of measurement ( _F0 ) according to the following formula 2, and the foam retention was evaluated according to the following criteria. A commercially available foam pump was used to foam the liquid detergent composition.
(Formula 2)
Foam retention rate (%) = F ₁ /F ₀ ×100 (2)

<Evaluation criteria>
Good: Foam retention is 90% or more.
Δ: Foam retention rate is 80% or more but less than 90%.
×: Foam retention rate is less than 80%, or sufficient foaming is not obtained.
The evaluation was made as △ or ◯, and the evaluation was made as practical.

*5: Rinseability test <Test method>
This test was conducted on 10 panelists who had been trained in the evaluation of rinsing performance. Each panelist took one push (about 1 mL) of each liquid detergent composition in a commercially available foam pump onto their hand, washed their hands for 30 seconds, and then rinsed with tap water for 30 seconds. The rinsing performance was evaluated based on the following criteria, such as the speed of rinsing and the lack of tightness in the hands after rinsing.

<Evaluation criteria>
The rinsing ability was evaluated based on the following criteria: 4 points: good rinsing ability, 3 points: somewhat good rinsing ability, 2 points: somewhat poor rinsing ability, and 1 point: poor rinsing ability. The average value was calculated and the rinsing ability was evaluated according to the following criteria.

◎: Average value is 3.4 points or higher.
○: Average value is 2.7 points or more and less than 3.4 points.
△: Average value is 2.0 points or more and less than 2.7 points.
×: Average value is less than 2.0 points.
The items were judged as practical with △, ○, and ◎.

*6: Skin irritation test <Test method>
This test was conducted with 10 panelists per Example. The panelists did not conduct the cleaning property test, rinsing property test, and skin irritation test of the liquid detergent composition described in other Examples during this test. Each panelist took 1 mL of the liquid detergent composition on their hands, washed their hands for 30 seconds, and then rinsed them with tap water for 30 seconds. This hand-washing action was repeated three times a day for seven days, and the skin irritation was evaluated based on the condition of each panelist's hands after seven days according to the following criteria.

<Evaluation criteria>
4 points: no roughness at all 3 points: slight roughness 2 points: roughness in places 1 point: considerable roughness The skin irritation was evaluated using a score and the average value was calculated, and the skin irritation was evaluated according to the following criteria.

◎: Average value is 3.5 points or more.
○: Average value is 3.0 points or more and less than 3.5 points.
△: Average value is 2.5 points or more and less than 3.0 points.
×: Average value is less than 2.5 points.
The items were judged as practical with △, ○, and ◎.

*7: Storage stability test <Test method>

200 ml of each liquid detergent composition was placed in a 250 ml transparent polypropylene container, the container was covered, and the container was stored and left to stand in a thermostatic chamber at -5°C, 25°C, or 40°C. After one month, the appearance was observed.

<Evaluation criteria>
○: No separation or turbidity was observed and the mixture was stable.
Δ: No overall separation, slight turbidity observed, but no problem in use.
×: Separation or turbidity is observed.
The evaluation was made as △ or ◯, and the evaluation was made as practical.

Claims (5)

An alkyltrimethylammonium salt as the component (A-α),
an alkyldimethylbenzylammonium salt as the (A-β) component;
(B) a pH adjuster comprising a combination of an alkali metal hydroxide and/or an alkanolamine with at least one selected from an alkali metal carbonate, an alkali metal phosphate, and an organic acid salt ;
As the component (C), 0.1 mass % or more and 6 mass % or less of at least one selected from a nonionic surfactant and an amphoteric surfactant,
As the component (D), a polyhydric alcohol which is at least one selected from the group consisting of ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, 1,3-butylene glycol, 1,4-butanediol, 1,5-pentanediol, hexylene glycol, glycerin, polyglycerin, and sorbitol; and as the component (E), water.
the total amount of the component (A-α) and the component (A-β) is 0.06% by mass or more and 0.5% by mass or less , the mass ratio of the component (A-α) to the component (A-β), (A-α)/(A-β), is 0.06 or more and 0.75 or less , and the pH at 25° C. is 8.0 or more and 12.0 or less. The alkaline liquid skin cleaner composition according to claim 1, wherein the mass ratio of the mass of the (C) component to the mass of the (A) component, (C) component/(A) component, is 0.1 or more and 150 or less. The alkaline liquid cleaner composition for skin according to claim 1 or 2, which contains, as component (C), at least one selected from polyoxyalkylene alkyl ethers, alkyl glucosides including alkyl polyglucosides, alkyl betaine-type amphoteric surfactants, alkyl imidazolinium betaine-type amphoteric surfactants, alkyl amino (mono- or di-)propionates, and alkyl dimethyl amine oxides. The alkaline liquid skin cleaner composition according to claim 1 or 2, which contains at least one selected from ethylene glycol, polyethylene glycol, propylene glycol, butylene glycol, 1,5-pentanediol, hexylene glycol, glycerin, and sorbitol as component (D). The alkaline liquid skin cleanser composition according to claim 1 or 2, wherein the alkaline liquid skin cleanser composition is a liquid cleanser for hands.