JP2009149573A - Antimicrobial agent - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antimicrobial agent having high antimicrobial activity and less irritation to skin, etc. <P>SOLUTION: The antimicrobial agent consisting of a quaternary ammonium salt is expressed by general formula (1), wherein R<SP>1</SP>is a 6-24C hydrocarbon group; R<SP>2</SP>and R<SP>3</SP>are each a 1-24C hydrocarbon group which may be substituted by hydroxy; R<SP>4</SP>is a 1-3C aliphatic hydrocarbon group which may be substituted by hydroxy; R<SP>5</SP>is a 1-5C alkylene; (p) is an integer of 1 to 3; (q) and (r) are each an integer of 0 to 2; (s) is an integer of 1 to 3; (p+q+r+s)=4; and A<SP>-</SP>is an anion. An antimicrobial composition containing the agent is also provided. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an antibacterial agent. Specifically, the present invention relates to an antibacterial agent having high antibacterial activity against Staphylococcus aureus and Escherichia coli and having low skin irritation and an antibacterial composition containing the same.

  Cationic surfactants have antibacterial and bactericidal action and are used as antibacterial agents, bactericides, disinfectants and the like. For example, disinfectants for medical equipment and affected areas, medical cleaners such as cleaning, household cleaners such as household dishes, food industry cleaners, antibacterial processing of textiles and synthetic resins, wood, daily necessities, shampoos, etc. Widely used in rinsing, cosmetics, etc.

  As such, the cationic surfactants conventionally used as antibacterial agents and the like include alkyltrimethylammonium salt, alkyldimethylethylammonium salt, alkyldimethylbenzylammonium salt, dialkyldimethylammonium salt, alkylpyridinium salt, And quaternary ammonium salts such as alkylquinolinium salts (for example, see Non-Patent Documents 1 and 2). However, these conventional quaternary ammonium salts have drawbacks such as great irritation to skin and the like, and poor biodegradability.

On the other hand, a cationic surfactant having an amide group has been reported as having low skin irritation and excellent biodegradability (Patent Document 1), but it has not always been sufficiently satisfactory in terms of antibacterial properties. .
"Anti-bacteria-proof handbook", Gihodo Publishing Co., Ltd., published on May 25, 1986, P510-511 "New edition surfactant handbook", Engineering Books Co., Ltd., October 1, 1987, P538 JP 2004-83562 A

  An object of the present invention is to provide an antibacterial agent having high antibacterial activity and less irritation on the skin or the like.

  The present invention is an antibacterial agent comprising a quaternary ammonium salt represented by the general formula (1) (hereinafter referred to as quaternary ammonium salt (1)), and an antibacterial composition containing the antibacterial agent.

(In the formula, R ¹ is a hydrocarbon group having 6 to 24 carbon atoms, R ² and R ³ are each independently a hydrocarbon group optionally substituted by a hydroxy group having 1 to 24 carbon atoms, and R ⁴ is carbon. An aliphatic hydrocarbon group which may be substituted with a hydroxy group of 1 to 3, R ⁵ represents an alkylene group of 1 to ⁵ carbon atoms, p is an integer of 1 to 3, q and r are each independently 0; An integer of ˜2, s is an integer of 1 to 3, and p + q + r + s = 4, and A ⁻ represents an anion.)
In addition, the quaternary ammonium salt (1) which is the antibacterial agent of the present invention is used for the purpose of antibacterial, sterilization, disinfection, antifungal and the like, and they are collectively referred to as an antibacterial agent.

  According to the present invention, an antibacterial agent having high antibacterial activity and less irritation on the skin or the like can be provided. Moreover, since the quaternary ammonium salt (1) has an amide bond and is excellent in biodegradability, the present invention can provide an antibacterial agent with high environmental safety.

  In the quaternary ammonium salt (1), p is an integer of 1 to 3, and 1 or 2 is preferable and 1 is more preferable from the viewpoint of ease of production and cost.

R ¹ is a hydrocarbon group having 6 to 24 carbon atoms, preferably a hydrocarbon group having 8 to 22 carbon atoms, and more preferably an aliphatic hydrocarbon group. Further, when p is 1, R ¹ is preferably an aliphatic hydrocarbon group having 10 to 22 carbon atoms, more preferably a linear or branched alkyl group having 12 to 18 carbon atoms, and 12 to 18 carbon atoms. A linear alkyl group is more preferred. When p is 2, R ¹ is preferably an aliphatic hydrocarbon group having 8 to 16 carbon atoms, more preferably a linear or branched alkyl group having 10 to 14 carbon atoms, and a linear chain having 10 to 14 carbon atoms. The alkyl group is more preferable.

R ² and R ³ are each independently a hydrocarbon group that may be substituted with a hydroxy group having 1 to 24 carbon atoms, and an aliphatic hydrocarbon that may be substituted with a hydroxy group having 1 to 24 carbon atoms Group, more preferably a linear or branched alkyl group or a hydroxyalkyl group having 1 to 3 carbon atoms, more preferably a linear alkyl group having 1 or 2 carbon atoms or a hydroxyalkyl group having 2 or 3 carbon atoms. A methyl group is particularly preferred.

R ⁴ is an aliphatic hydrocarbon group which may be substituted with a hydroxy group having 1 to 3 carbon atoms, preferably a linear or branched alkyl group or hydroxyalkyl group having 1 to 3 carbon atoms, A linear alkyl group having 1 or 2 or a hydroxyalkyl group having 2 or 3 carbon atoms is more preferable, and a methyl group, an ethyl group, or a hydroxyethyl group is still more preferable.

R ⁵ is an alkylene group having 1 to 5 carbon atoms, which may be linear or branched, but is preferably a linear or branched alkylene group having 1 to 4 carbon atoms, and is linear or branched having 1 to 3 carbon atoms. A chain alkylene group is more preferable, and residues obtained by removing a carboxyl group and an amino group from glycine, alanine or β-alanine, that is, —CH ₂ —, —CH (CH ₃ ) —, —CH ₂ CH ₂ — are more preferable. preferable.

  q and r are each independently an integer of 0 to 2, an integer of 0 to 2 when p is 1, 0 or 1 when p is 2, and 0 when p is 3. s is an integer of 1 to 3, and is preferably 1. However, p + q + r + s = 4.

A ⁻ is an anion, specifically, halogen ions such as Cl ⁻ and Br ⁻ , alkyl sulfate ions such as methyl sulfate and ethyl sulfate, sulfate ions, paratoluene sulfonate ions, alkyl such as methyl phosphate and ethyl phosphate. Phosphate ion, phosphate ion, carbonate or carbonate ion, formic acid, acetic acid, propionic acid, butyric acid, glycolic acid, gluconic acid, lactic acid, glutamic acid, malic acid, tartaric acid, citric acid, maleic acid, malonic acid, succinic acid Organic acid ions such as From the viewpoint of ease of production and cost, Cl ⁻ , Br ⁻ , methyl sulfate ion, ethyl sulfate ion, p-toluenesulfonate ion, carbonate and carbonate ion, and acetic acid, propionic acid, glycolic acid, gluconic acid, lactic acid An organic acid ion selected from the group consisting of Cl ⁻ , methyl sulfate ion, ethyl sulfate ion, and an organic acid ion selected from acetic acid, propionic acid, and glycolic acid is more preferable.

  Although the manufacturing method of quaternary ammonium salt (1) is not specifically limited, For example, it can manufacture by the following methods 1 and 2.

  Method 1: First, the corresponding alkylamine is reacted with a halogenated carboxylic acid or its lower alcohol ester or acid halide, optionally using a catalyst, and then the corresponding amine or the like is reacted to give a tertiary intermediate of the reaction intermediate. An amine or directly a quaternary ammonium salt (1) is obtained, and a tertiary amine as a reaction intermediate is quaternized with a quaternizing agent in a solvent such as ethanol or a lower alcohol such as isopropyl alcohol or water. A method for obtaining a quaternary ammonium salt (1).

  Method 2: An amino acid or a derivative thereof and an alkylamine are reacted with a catalyst in some cases to obtain a tertiary amine as a reaction intermediate. Further, the tertiary amine as a reaction intermediate is obtained in the same manner as in Method 1. A method of obtaining a quaternary ammonium salt (1) by quaternization with a quaternizing agent.

  Examples of the quaternizing agent include alkyl halides such as methyl chloride, ethyl chloride, and methyl bromide, dialkyl sulfates such as dimethyl sulfate and diethyl sulfate, and alkylene oxides such as ethylene oxide and propylene oxide. In addition, when performing quaternization with alkylene oxide, it is necessary to add an acid which becomes a counter ion, and the timing of adding the acid is added all at once before or during the reaction or after the reaction. .

  The method of using the antibacterial agent of the present invention is not particularly limited, and can be applied to various objects. For example, commonly employed methods such as a method of spraying on an object to be subjected to antibacterial treatment, a method of applying, a method of impregnating the object, and a method of immersing the object can be used as they are. When the antibacterial treatment is actually performed, the antibacterial agent of the present invention may be used as it is, but is usually water or a water-water-soluble organic solvent, preferably 0.001 to 5% by mass, more preferably 0. Used by diluting to about 01 to 1% by mass. Or it can add to these as an antibacterial component contained in a cleaning agent or a disinfectant.

  The antibacterial composition of the present invention contains the antibacterial agent of the present invention, and other components such as a water-soluble organic solvent, a chelating agent, a surfactant, other bactericides, a thickener, a reducing agent, depending on the use. A viscosity agent, a pH adjuster, inorganic salts, a fragrance, a coloring agent, a pearling agent, a bulking agent, an enzyme, an abrasive, a binder and the like can be contained.

  0.001-5 mass% is preferable, as for content of the antimicrobial agent of this invention in the antimicrobial composition of this invention, 0.01-1 mass% is more preferable, and 0.1-1 mass% is still more preferable.

  The antibacterial agent and antibacterial composition of the present invention can be used in the same manner as known antibacterial agents, disinfectants, disinfectants, and antifungal agents for the purpose of antibacterial, sterilization, disinfection, antifungal and the like. The use mode includes: medical cleaning agents for the purpose of disinfecting and cleaning medical instruments and affected parts, household cleaning agents for sterilizing and cleaning dishes, food industry cleaning agents, lubricants for container transfer conveyors, food packaging films , Antibacterial agents for antibacterial processing of fibers, synthetic resins, wood, daily necessities, shampoos, rinses, hand soaps, body soaps, cleansing creams, cosmetics, softeners for clothing, aqueous or non-aqueous paints, Examples include a method of impregnating a nonwoven fabric or the like and using it as a wet tissue, toilet seat cleaner or the like. When used as an antibacterial agent for fibers, all fibers such as cotton, polyester, acrylic and nylon may be treated by a general method such as stirring treatment, dipping treatment, spray treatment and the like. Moreover, it can also apply | coat or spray or inject | pour on the surface to wood, daily necessities, etc. Moreover, when using about synthetic resin etc., you may make it adhere to the surface by apply | coating or spraying after shaping | molding, and can also knead | mix at the time of a shaping | molding process etc. in order to maintain an antimicrobial effect.

  In the following examples, “%” is based on mass unless otherwise specified.

Synthesis Example 1: Synthesis of quaternary ammonium salt (1-1) In a four-necked flask equipped with a stirrer, a thermometer, a dehydration tube, and a nitrogen introduction tube, 185 g of Farmin 20 (manufactured by Kao Corporation) and N, 157 g of N-dimethylglycine ethyl ester was added, 2 mol% (3.9 g) of methanol solution of 28% sodium methylate was added as a catalyst, and the reaction was carried out while distilling off the ethanol produced at 100 ° C. for 3 hours. Then, 2% of Kyoward 600S (Kyowa Chemical Industry Co., Ltd.) was added to the total charge and mixed, then filtered off, and excess N, N-dimethylglycine ethyl ester was distilled off. As a result, 251 g of a tertiary amine was obtained. Next, an autoclave equipped with a stirrer and a thermometer was charged with 0.5 mol (135 g) of tertiary amine, 56 g of methyl chloride, and 2-propyl alcohol as a solvent in the same amount with respect to the total amount charged, at 70 to 90 ° C. After completion of the reaction by maintaining for 3 hours, the solvent was distilled off, and in general formula (1), R ¹ was n-C ₁₂ H ₂₅ , R ⁵ was —CH ₂ —, R ² = R ³ = There was obtained 155 g of a compound wherein R ⁴ = methyl group, p = q = r = s = 1, and A ⁻ was Cl ⁻ . As a result of analyzing the composition by ¹ H NMR, the purity of the quaternary ammonium salt was 98.6%, the tertiary amine and its salt 0.9%, and 2-propyl alcohol 0.5%.

Synthesis Example 2: Synthesis of Quaternary Ammonium Salt (1-2) Instead of using Pharmamin 20 of Synthesis Example 1, 213 g of tetradecylamine (manufactured by Tokyo Chemical Industry Co., Ltd .: purity> 95%) was used. The same raw materials and conditions as in Synthesis Example 1 were used. In the general formula (1), R ¹ is n-C ₁₄ H ₂₉ , R ⁵ is —CH ₂ —, R ² = R ³ = R ⁴ = methyl group, p = Q = r = s = 1, and 164 g of a compound in which A ⁻ is Cl ⁻ was obtained. The composition was a quaternary ammonium salt purity of 98.5%, a tertiary amine and its salt 0.8%, and 2-propyl alcohol 0.7%.

Synthesis Example 3 Synthesis of Quaternary Ammonium Salt (1-3) Instead of using Pharmamin 20 of Synthesis Example 1 except that 241 g of hexadecylamine (manufactured by Tokyo Chemical Industry Co., Ltd .: purity> 90%) was used, The reaction was carried out under the same raw materials and conditions as in Synthesis Example 1. In the general formula (1), R ¹ is n-C ₁₆ H ₃₃ , R ⁵ is —CH ₂ —, R ² = R ³ = R ⁴ = methyl group, p = Q = r = s = 1, and 176 g of a compound in which A ⁻ is Cl ⁻ was obtained. The composition was a quaternary ammonium salt purity of 98.0%, a tertiary amine and its salt 1.2%, and 2-propyl alcohol 0.8%.

Synthesis Example 4: Synthesis of Quaternary Ammonium Salt (1-4) The same raw material as in Synthesis Example 1 except that 270 g of Farmin 80 (manufactured by Kao Corporation) was used instead of Farmin 20 in Synthesis Example 1. In the general formula (1), R ¹ is nC ₁₈ H ₃₇ , R ⁵ is —CH ₂ —, R ² = R ³ = R ⁴ = methyl group, p = q = r = s = 1. 191 g of a compound in which A ⁻ is Cl ⁻ was obtained. The composition was 98.5% quaternary ammonium salt purity, 1.0% tertiary amine and its salt, and 0.5% 2-propyl alcohol.

Synthesis Example 5: Synthesis of quaternary ammonium salt (1-5) 0.5 mol (135 g) of tertiary amine obtained in the same manner as in Synthesis Example 1 and 41 g of propionic acid in an autoclave equipped with a stirrer and a thermometer Then, 20 g of solvent water, 200 g of 2-propyl alcohol, and 44 g of ethylene oxide were charged and kept at 60 to 85 ° C. for 5 hours to complete the reaction. Then, after distilling off the solvent, crystallization with acetone is performed, and after drying, in general formula (1), R ¹ is nC ₁₂ H ₂₅ , R ⁵ is —CH ₂ —, R ² = R ³ = methyl. 145 g of the compound, wherein R ⁴ is a hydroxyethyl group, p = q = r = s = 1, and A ⁻ is CH ₃ CH ₂ COO ⁻ is obtained. The composition was 99.1% pure quaternary ammonium salt, 0.7% tertiary amine and salts thereof, and 0.2% water.

Synthesis Example 6 Synthesis of Quaternary Ammonium Salt (1-6) Synthesis Example except that the tertiary amine obtained by the same method as in Synthesis Example 3 was used in place of the tertiary amine of Synthesis Example 5. The same raw materials and conditions as in Example 5 are used. In the general formula (1), R ¹ is n-C ₁₆ H ₃₃ , R ⁵ is —CH ₂ —, R ² = R ³ = methyl group, and R ⁴ is hydroxyethyl group. , P = q = r = s = 1, and 169 g of a compound in which A ⁻ is CH ₃ CH ₂ COO ⁻ was obtained. The composition was 99.2% pure quaternary ammonium salt, 0.6% tertiary amine and salts thereof, and 0.2% water.

Synthesis Example 7 Synthesis of Quaternary Ammonium Salt (1-7) In a four-necked flask equipped with a stirrer, thermometer, dehydration tube, and dropping funnel, hexadecylamine (manufactured by Tokyo Chemical Industry Co., Ltd .: purity> 90 %) Was added 241 g, methanol 500 g, and 28% sodium methylate methanol solution 3 mol% (5.8 g) as a catalyst, and 135 g of 2-chloropropionic acid methyl ester was added dropwise over 1 hour while maintaining at 15 to 20 ° C. Thereafter, the reaction was allowed to proceed for 24 hours. After the reaction, the precipitated crystals were filtered, washed with 300 g of methanol and dried to obtain 271 g of the corresponding chloroacetamide. Next, 249 g of the above chloroacetamide, 169 g of dimethylamine and 500 g of 2-propyl alcohol were put into an autoclave equipped with a stirrer and a thermometer, and reacted at 50 ° C. for 10 hours. After the reaction, 61.7 g of 48% aqueous sodium hydroxide and 100 g of ion-exchanged water were added, excess dimethylamine and the solvent were distilled off under reduced pressure, desalting and crystallization with acetone were performed. 221 g of a tertiary amine was obtained. Furthermore, in an autoclave equipped with a stirrer and a thermometer, 170 g of tertiary amine, 61 g of methyl chloride, and 2-propyl alcohol as a solvent were charged in the same amount with respect to the total charge, and kept at 70 to 90 ° C. for 4 hours for reaction. After completion of the process, the solvent was distilled off, and after drying, in general formula (1), R ¹ was n-C ₁₆ H ₃₃ , R ⁵ was —CH (CH ₃ ) —, R ² = R ³ = R ⁴ = Methyl group, p = q = r = s = 1, and A ⁻ is Cl ⁻ to obtain 189 g of a compound. The composition was quaternary ammonium salt purity of 98.3%, tertiary amine and its salt 1.5%, 2-propyl alcohol 0.2%.

Synthesis Example 8: Synthesis of Quaternary Ammonium Salt (1-8) In a reaction apparatus similar to Synthesis Example 1, 157 g of decylamine (manufactured by Wako Pure Chemical Industries, Ltd.) and 73.5 g of N-methyliminodiacetic acid were charged. After reacting while distilling off water produced at 10 ° C. for 10 hours, acetone crystallization was performed, and after drying, 201 g of the corresponding tertiary amine was obtained. Next, in an autoclave equipped with a stirrer and a thermometer, 0.3 mol (128 g) of a tertiary amine, 18 g of methyl chloride, and ethyl alcohol as a solvent were added in an amount twice as much as the total amount of addition, and 80 to 95 ° C. After completion of the reaction by holding for a time, the solvent was distilled off, and after drying, in general formula (1), R ¹ was n-C ₁₀ H ₂₁ , R ⁵ was —CH ₂ —, R ² = R ⁴ = 139 g of a compound having a methyl group, p = 2, q = 1, r = 0, s = 1, and A ⁻ is Cl ⁻ was obtained. The composition was quaternary ammonium salt purity 97.5%, tertiary amine and its salt 2.1%, decylamine and its salt 0.1%, ethyl alcohol 0.3%.

Synthesis Example 9: Synthesis of Quaternary Ammonium Salt (1-9) The same raw materials and conditions as in Synthesis Example 8 except that 185 g of Farmin 20 (manufactured by Kao Corporation) was used in place of the decylamine of Synthesis Example 8. In general formula (1), R ¹ is n-C ₁₂ H ₂₅ , R ⁵ is —CH ₂ —, R ² = R ⁴ = methyl group, p = 2, q = 1, r = 0, s = 1, 149 g of a compound in which A ⁻ is Cl ⁻ was obtained. The composition was 97.2% pure quaternary ammonium salt, 2.1% tertiary amine and its salt, 0.3% dodecylamine and its salt, 0.4% ethyl alcohol.

Synthesis Example 10: Synthesis of quaternary ammonium salt (1-10) In the same reaction apparatus as in Synthesis Example 1, 48 g of quaternary ammonium salt (1-8), 12 g of propionic acid, 100 g of solvent water and 100 g of ethyl alcohol After stirring at 75 ° C. for 1 hour, the solvent was replaced with ethyl alcohol by repeatedly removing the solvent and adding ethyl alcohol. Next, the crystalline precipitate is removed by filtration, and then the ethyl alcohol is distilled off. After drying, in general formula (1), R ¹ is n-C ₁₀ H ₂₁ , R ⁵ is —CH ₂ —, R ² = R ^4. = methyl group, p = 2, q = 1 , r = 0, s = 1, a - is CH ₃ CH ₂ COO ^- give compounds wherein 51 g. Composition is quaternary ammonium salt purity 97.3%, tertiary amine and its salt 2.1%, decylamine and its salt 0.1%, ethyl alcohol 0.2%, NaCl 0.3%, A ^In 96% of Cl ⁻ , CH ₃ CH ₂ COO ⁻ was substituted.

Synthesis Example 11: Synthesis of Quaternary Ammonium Salt (1-11) The same procedure as in Synthesis Example 10 was carried out except that 98 g of Na acetate was used instead of Na propionate in Synthesis Example 10, and the general formula ( 1), R ¹ is n-C ₁₀ H ₂₁ , R ⁵ is —CH ₂ —, R ² = R ⁴ = methyl group, p = 2, q = 1, r = 0, s = 1, and A ⁻ is to give compounds wherein 49g ^- CH ₃ COO. Composition is quaternary ammonium salt purity 97.3%, tertiary amine and its salt 2.1%, decylamine and its salt 0.1%, ethyl alcohol 0.1%, NaCl 0.4%, A ^- is Cl ^- 95% of CH ₃ COO ^- was substituted with.

Examples 1-11 and Comparative Examples 1-5
As the antibacterial agent of the present invention, the quaternary ammonium salts (1-1) to (1-11) obtained in Synthesis Examples 1 to 11, and the following quaternary ammonium salt (2-1) as a comparative antibacterial agent. Using (2-5), antibacterial properties and skin irritation were evaluated by the following methods. The results are shown in Table 1.

<Comparison antibacterial agent>
Quaternary ammonium salt (2-1): In the following formula (2), R ⁶ is n-C ₁₄ H ₂₉ , R ² = R ³ = R ⁴ = methyl group, p = q = r = s = 1, a ^- is Cl ^-, compound quaternary ammonium salt (2-2): in formula (2), R ⁶ is _{n-C 10 H 21, R} 2 = R 4 = methyl, p = 2, q = 1, r = 0, s = 1, A ⁻ is Cl ⁻ quaternary ammonium salt (2-3): In the following formula (2), R ⁶ is nC ₁₄ H ₂₉ , R ² = Compound in which R ³ = methyl group, R ⁴ = benzyl group, p = q = r = s = 1, and A ⁻ is Cl ⁻ Quaternary ammonium salt (2-4): In the following formula (2), R ⁶ Is a compound in which n-C ₁₁ H ₂₃ CONHC ₃ H ₆ , R ² = R ³ = R ⁴ = methyl group, p = q = r = s = 1, and A ⁻ is Cl ⁻ quaternary ammonium salt (2- 5): In the following formula (2) Te, R ⁶ is _{n-C 11 H 23 CONHC 3} H 6, R 2 = R 4 = methyl, p = 2, q = 1 , r = 0, s = 1, A - is Cl ^-, compound

<Antimicrobial evaluation method>
As test compounds, the antibacterial agents of the present invention shown in Table 1 and comparative antibacterial agents are used, and MIC (Minimum Growth Inhibitory Concentration) and MBC (Minimum Bactericidal Concentration), which are general antibacterial evaluation methods, are diluted in a small amount of liquid. The antibacterial activity against Escherichia coli (Escherichia coli IFO3972) and Staphylococcus aureus IFO13276 was tested according to the method (Reference: Newly Revised GMP Microorganism Test Method June 1, 2000, Kodansha).

A medium, sterilized water, a specimen (test compound), and each bacterium were placed in a sterilized plastic cell to make a total volume of 200 μL. As the medium, an SCD (SOYBEAN-CASEIN DIGEST BROTH) medium was used as a medium for MIC. The bacterial concentration was about 2 × 10 ⁶ CFU / mL (CFU: Colony Forming Unit). Test compound concentrations were adjusted to 400, 200, 100, 50, 25, 12.5, 6.3, 3.1, 1.6, 0.8, 0.4, and 0.2 ppm. Then, after culturing at 35 ° C. for 24 hours, the MIC of bacterial growth was determined with a turbidimeter. Subsequently, the internal solution of the cell in which no bacterial growth was observed was transplanted into an MBC medium containing no test compound, and re-cultured for 48 hours in the same manner to determine MBC. As the medium for MBC, SCDLP (SOYBEAN-CASEIN DIGEST BROTH with LECITHIN & POLYSORBATE 80) medium was used.
The lower the concentration of MIC and MBC, the stronger the antibacterial activity of the test compound and the better the antibacterial property.

<Method for evaluating skin irritation>
Using the antibacterial agent of the present invention and the comparative antibacterial agent shown in Table 1 as test compounds, skin irritation was evaluated by a patch test. A 10% aqueous solution of the test compound was prepared, and 100 mg was applied to the gauze part of the adhesive bandage for patch test and attached to the back side of the upper arm part. After 48 hours, the adhesive bandage was peeled off and left for 3 hours, and then the presence or absence of erythema was visually observed. The test was conducted on 10 men and women, and the evaluation was performed according to the following criteria.

Evaluation criteria A: There was no person with erythema.
B: One person had erythema.
C: Two people had erythema.
D: There were 3 or more people with erythema.

Claims (4)

An antibacterial agent comprising a quaternary ammonium salt represented by the general formula (1).

(In the formula, R ¹ is a hydrocarbon group having 6 to 24 carbon atoms, R ² and R ³ are each independently a hydrocarbon group optionally substituted by a hydroxy group having 1 to 24 carbon atoms, and R ⁴ is carbon. An aliphatic hydrocarbon group which may be substituted with a hydroxy group of 1 to 3, R ⁵ represents an alkylene group of 1 to ⁵ carbon atoms, p is an integer of 1 to 3, q and r are each independently 0; An integer of ˜2, s is an integer of 1 to 3, and p + q + r + s = 4, and A ⁻ represents an anion.) In the general formula (1), p is 1, R ¹ is an aliphatic hydrocarbon group having 10 to 22 carbon atoms, R ² and R ³ are each independently an alkyl group or hydroxyalkyl group having 1 to 3 carbon atoms, R ⁴ is an alkyl group or hydroxyalkyl group having 1 to 3 carbon atoms, R ⁵ is an alkylene group having 1 to 3 carbon atoms, q and r are each independently an integer of 0 to 2, and s is 1. Antibacterial agent. In the general formula (1), p is 2, R ¹ is an aliphatic hydrocarbon group having 8 to 16 carbon atoms, R ² and R ³ are each independently an alkyl group or hydroxyalkyl group having 1 to 3 carbon atoms, R The antibacterial according to claim 1, wherein ⁴ is an alkyl group or hydroxyalkyl group having 1 to 3 carbon atoms, R ⁵ is an alkylene group having 1 to 3 carbon atoms, q and r are each independently 0 or 1, and s is 1. Agent.   The antibacterial composition containing the antibacterial agent of any one of Claims 1-3.