JP5972780B2 - Biofilm removal method - Google Patents

Description

  The present invention relates to a biofilm removal method.

  A biofilm is also called a biofilm or slime, and is generally formed by a high-molecular substance such as a polysaccharide, protein, or nucleic acid produced by a microbial cell when a microorganism such as a fungus adheres to the surface of a substance and grows in an aqueous system. A structure that wraps microorganisms. When a biofilm is formed, various problems due to microorganisms occur, which is a problem in various industrial fields.

  For example, when a biofilm is formed in the piping of a food plant, the biofilm may be peeled off and mixed into the product as a foreign substance, or may cause food poisoning due to toxins derived from bacteria. In addition, biofilm formation on the metal surface causes metal corrosion and promotes aging of equipment. In the medical field, it is known that microorganisms remaining in narrow gaps and voids of medical devices such as endoscopes form biofilms and cause nosocomial infections. In addition, it is known that a biofilm called dental plaque (dental plaque) is formed on the teeth in the human oral cavity, causing caries and periodontal disease.

  In order to prevent harm caused by biofilms, the idea of not allowing bacteria to grow by giving bactericidal or bacteriostatic action to microorganisms, particularly bacteria, has been generally studied. However, in many cases, a microorganism control agent such as a bactericide or bacteriostatic agent does not sufficiently act on a microorganism aggregate forming a biofilm as compared to a microorganism in a dispersed and floating state. For this reason, the method of preventing the harm by a biofilm is examined (for example, refer patent documents 1-3).

JP 2006-188648 A JP 2009-149775 A JP 2009-149776 A

  However, Patent Document 1 aims to improve the sterilization effect of a detergent containing a high concentration of surfactant. Patent Document 1 describes a composition containing 2-ethylhexyl glyceryl ether, methyl glycine diacetic acid, and amine oxide. However, what is disclosed in Examples and the like is a composition in which the content of amine oxide in the composition is 4% by mass or more, or a composition not containing amine oxide. Not considering.

  Patent Documents 2 and 3 describe that methylglycine diacetate is used as a washing agent for washing tubs or pipes, and it is said that biofilms and the like can be removed with manganese compounds and copper compounds. Although Patent Document 2 and Patent Document 3 have a general description of nonionic surfactants, there is no disclosure of specific examples of compositions. Further, Patent Document 2 and Patent Document 3 do not sufficiently study the removal of biofilm.

  An object of the present invention is to provide a method for effectively removing a biofilm.

  In the method for removing a biofilm of the present invention, 0.005 to 0.5% by mass of 2-ethylhexyl glyceryl ether is used as the component (a), and methylglycine-N, N-diacetic acid or a salt thereof is set to 0.005 as the component (b). 005 to 0.5% by mass, and a biofilm removing aqueous solution containing 0.2 to 2% by mass of a nonionic solubilizer as component (c) is brought into contact with the surface on which the biofilm is present.

  According to the biofilm removal method of the present invention, the biofilm can be effectively removed.

  In the method for removing a biofilm according to this embodiment, a biofilm removing aqueous solution containing predetermined amounts of the following components (a), (b), and (c) is brought into contact with the surface on which the biofilm is present. Thereby, it becomes possible to remove a biofilm effectively.

<(A) component>
The component (a) is 2-ethylhexyl glyceryl ether. The component (a) 2-ethylhexyl glyceryl ether is obtained by reacting 2-ethylhexanol with an epoxy compound such as epihalohydrin or glycidol using an acid catalyst such as boron trifluoride (BF ₃ ) or an aluminum catalyst. Can be manufactured. When manufactured by such a method, it becomes a mixture containing a plurality of products (for example, see JP-A-2001-49291).

  Specifically, the component (a) may be a mixture of 2-ethylhexyl monoglyceryl ether and a by-product polyaddition compound. 2-ethylhexyl monoglyceryl ether is a compound in which 2-ethylhexanol is added to the 1-position of an epoxy compound (3- (2-ethylhexyloxy) -1,2-propanediol, hereinafter referred to as (a1)), and epoxy A compound added to the 2-position of the compound (2- (2-ethylhexyloxy) -1,3-propanediol, hereinafter referred to as (a2)) can be mentioned. Moreover, as a by-product, the polyaddition compound (henceforth (a3)) which further added the epoxy compound to (a1) or (a2) can be mentioned.

  In the present embodiment, the content of the component (a3) in the component (a) is preferably 30% by mass or less, more preferably 10% by mass or less, and further preferably 1% by mass or less.

<(B) component>
The component (b) is methylglycine-N, N-diacetic acid (MGDA) or a salt thereof. Examples of MGDA salts include MGDA sodium, MGDA disodium, MGDA dipotassium, MGAD tripotassium, and MGDA ammonium. The component (b) may be any of MGDA, a salt of MGDA, and a mixture of a salt of MGDA and MGDA. Further, the salt of MGADA may be a single salt or a mixture of a plurality of salts.

<(C) component>
The component (c) is a nonionic solubilizer for solubilizing the component (a). The nonionic solubilizer is one or two selected from alkyl glycoside surfactants, amine oxide surfactants, polyoxyethylene alkyl ether surfactants, polyoxyalkylene alkenyl ether surfactants and solvents. The above is preferable, and one or more selected from alkylglycoside surfactants and amine oxide surfactants are more preferable.

  As the alkyl glycoside surfactant, a compound represented by the following general formula (1) can be used. In the embodiment of the present invention, the concept of alkyl glycoside includes alkyl monoglycoside, alkyl oligoglycoside, and alkyl polyglycoside.

R ¹¹ − (OR ¹² ) _m1 G _t (1)

In the general formula (1), R ¹¹ is a linear alkyl group having 8 to 16 carbon atoms, preferably 10 to 16 carbon atoms, more preferably 10 to 14 carbon atoms. R ¹² is an alkylene group having 2 to 4 carbon atoms, preferably an ethylene group or a propylene group, more preferably an ethylene group. G is a residue derived from a reducing sugar. m1 is the average number of added moles, the value of m1 is a number from 0 to 6, preferably a number from 0 to 3, more preferably 0, t is the average degree of condensation of sugars, and the value is from 1 to 10 The number is preferably 1 to 5, more preferably 1 to 2.

  In the general formula (1), the reducing sugar as a raw material may be either aldose or ketose. For example, triose, tetrose, pentose, and hexose having 3 to 6 carbon atoms can be used. As aldose, for example, apiose, arabinose, galactose, glucose, lyxose, mannose, galose, aldose, idose, talose, xylose can be used. For example, fructose can be used as the ketose. In the present embodiment, aldopentose or aldohexose having 5 or 6 carbon atoms is particularly preferred, and glucose is most preferred.

The compound of the formula (1) can be easily synthesized by subjecting sugar and R ¹¹ — (OR ¹² ) _m1 —OH to an acetalization reaction or a ketalization reaction using an acid catalyst. In the case of an acetalization reaction, a hemiacetal structure or a normal acetal structure may be used.

  As the amine oxide surfactant, an amine oxide surfactant having a hydrocarbon group having 10 to 18 carbon atoms and an alkyl group having 1 to 3 carbon atoms or a hydroxyalkyl group having 1 to 3 carbon atoms may be used. it can. Among these, a compound represented by the following general formula (2) is preferable.

However, in the general formula (2), R ²¹ is a hydrocarbon group having 6 to 14 carbon atoms, R ²² is an alkylene group having 1 to 3 carbon atoms, and R ²³ and R ²⁴ are each independently a carbon number. 1 or more, 6 or less, preferably 3 or less alkyl group, or a hydroxyalkyl group having 1 to 3 carbon atoms, Y ²¹ represents —COO—, —OCO—, —NHCO—, —CONH—, and —O—. A group selected from: m2 is 0 or 1;

In general formula (2), from the viewpoint of improving solubility, a compound in which R ²¹ is an alkyl group having 8 to 12 carbon atoms, R ²³ and R ²⁴ are both methyl groups, and m2 is 0 is particularly preferable. . Specifically, dimethylalkyl (6 to 14 carbon atoms) amine oxide is preferably used, dimethylalkyl (8 to 12 carbon atoms) amine oxide is more preferably used, and dimethyllaurylamine oxide is used. More preferably.

In the general formula (2), R ²¹ may be a single alkyl (or alkenyl) group having the same chain length or a mixed alkyl group (or alkenyl group) having different chain lengths. In the latter case, those having a mixed alkyl (or alkenyl) chain length derived from a vegetable oil selected from coconut oil and palm kernel oil are preferred. Specifically, a mixture of a lauryl group (or lauric acid residue) and a myristyl group (or myristic acid residue) is preferable. The molar ratio of the lauryl group (or lauric acid residue) to the myristyl group (or myristic acid residue) is 95/5 or more and 20/80 or less, preferably 90/10 or more and 30/70 or less. From the viewpoint of improving solubility.

  As the polyoxyethylene alkyl ether type surfactant and the polyoxyalkylene alkenyl ether type surfactant, a compound represented by the following general formula (3) can be used.

R ³¹ —O— (R ³² O) _{m 3} —H (3)

In the general formula (3), R ³¹ is an alkyl group or alkenyl group having 8 to 16 carbon atoms, R ³² is an alkylene group having 2 to 3 carbon atoms, m3 is an average addition mole number, and its value is 1-30. Is the number of

From the viewpoint of improving solubility, R ³¹ preferably has 10 to 14 carbon atoms. R ⁷ is preferably an alkyl group. R ⁸ is preferably an ethylene group or a propylene group, and more preferably an ethylene group. m3 is preferably 1 to 25, more preferably 1.5 to 25, still more preferably 5 to 25, still more preferably 10 to 24, still more preferably 15 to 23, and still more preferably 20 to 22.

  The solvent is preferably a water-soluble organic solvent, for example, 1 selected from ethanol, isopropyl alcohol, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, glycerin, isoprene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, and the like. Species or two or more can be used.

<Aqueous solution for removing biofilm>
The aqueous solution for removing a biofilm of the present embodiment is an aqueous solution containing a predetermined amount of the component (a), the component (b), and the component (c).

  The content of the component (a) contained in the aqueous solution for removing a biofilm is 0.005% by mass or more, preferably 0.01% by mass or more, more preferably 0.04% by mass or more. Moreover, it is 0.5 mass% or less, Preferably, it is 0.25 mass% or less, More preferably, it is 0.1 mass% or less.

  The content of the component (b) contained in the aqueous solution for removing a biofilm is 0.005% by mass or more, preferably 0.01% by mass or more, more preferably 0.02% by mass or more. Moreover, it is 0.5 mass% or less, Preferably, it is 0.25 mass% or less, More preferably, it is 0.1 mass% or less.

  The content of the component (c) contained in the aqueous solution for removing a biofilm is 0.2% by mass or more, preferably 0.23% by mass or more, more preferably 0.27% by mass or more. Moreover, it is 2 mass% or less, Preferably, it is 1 mass% or less, More preferably, it is 0.5 mass% or less.

  The mass ratio (a) / (b) of the mass of the component (a) contained in the aqueous solution for removing a biofilm to the mass of the component (b) is not particularly limited, but is preferably 0.05 or more, more preferably 0.3 or more. More preferably, 1 or more is more preferable, 20 or less is preferable, 5 or less is more preferable, and 3 or less is more preferable.

  The remaining part of the aqueous solution for removing a biofilm excluding the component (a), the component (b), and the component (c) may be water. However, the aqueous solution for removing a biofilm may contain components other than the components (a), (b), (c) and water. The content of water in the aqueous biofilm removal solution is preferably 70% by mass or more, more preferably 80% by mass or more, still more preferably 90% by mass or more, and preferably 99.75% by mass. It is below, More preferably, it is 99.7 mass% or less, More preferably, it is 99.65 mass% or less. The water is not particularly limited, and ion exchange water, reverse osmosis (RO) water, distilled water, or the like can be used. Moreover, tap water etc. may be sufficient.

  The aqueous solution for removing a biofilm may contain a betaine surfactant as the component (d). The betaine surfactant is preferably one or more compounds represented by the following general formula (4).

In the general formula (4), R ⁴¹ is an alkyl group or alkenyl group having 10 to 16 carbon atoms, R ⁴² is an alkylene group having 1 to 6 carbon atoms, and R ⁴³ and R ⁴⁴ each have 1 to 3 carbon atoms. It is an alkyl group or a hydroxyalkyl group, and R ⁴⁵ is an alkylene group having 1 to 5 carbon atoms which may be substituted with a hydroxy group. Y ⁴¹ is a group selected from —COO—, —OCO—, —NHCO—, —CONH—, and —O—, and m4 is 0 or 1. D is a group selected from —COO ⁻ , —SO ₃ ⁻ , and —OSO ₃ ^— .

  More specifically, as a betaine-type surfactant, 2-alkyl (8 to 16 carbon atoms) -N-carboxymethyl-N-hydroxyethylimidazolinium betaine, lauryldimethylaminoacetic acid betaine, lauryl hydroxysulfobetaine , And one or more selected from lauric acid amidopropyl betaine are preferably used.

  The content of the betaine surfactant in the aqueous solution for removing a biofilm is not particularly limited, but is preferably 0.001% by mass or more, more preferably 0.005% by mass or more, and preferably 0.1% by mass or less. 0.07 mass% or less is more preferable.

  The aqueous solution for removing a biofilm preferably does not contain an anionic surfactant. However, an anionic surfactant may be included as long as the biofilm removal performance is not affected. The amount of the anionic surfactant contained in the aqueous solution for removing a biofilm is preferably 0.001% by mass or less, more preferably 0.0005% by mass or less, and still more preferably not contained.

  The hydrogen ion concentration (pH) at 20 ° C. of the aqueous solution for removing a biofilm is 5 or more, preferably 5.5 or more, more preferably 6 or more, from the viewpoint of further improving safety during use. Hereinafter, it is preferably 8.5 or less, more preferably 8 or less. The pH can be measured, for example, by the method described in the examples.

  The aqueous solution for removing a biofilm may be prepared by dissolving each component in water so as to have a predetermined concentration, or it may be prepared by diluting a dilution composition containing each component at a high concentration with water. Good. The dilution ratio in the case of preparing an aqueous solution for removing a biofilm by diluting a diluting composition containing each component at a high concentration with water is preferably 2 times by mass or more, more preferably 5 times by mass or more, and further preferably 10 times. It is more than mass times, and preferably is less than 200 mass times, more preferably less than 100 mass times, and still more preferably less than 50 mass times.

  The concentration of each component in the dilution composition may be as follows. The concentration of the component (a) is preferably 0.5% by mass or more, more preferably 1% by mass or more, further preferably 1.5% by mass or more, and preferably 10% by mass or less, more preferably 7% by mass. Hereinafter, it is more preferably 5% by mass or less, and still more preferably 4.5% by mass or less. The concentration of the component (b) is preferably 0.5% by mass or more, more preferably 1% by mass or more, further preferably 1.5% by mass or more, and preferably 10% by mass or less, more preferably 7% by mass. Hereinafter, it is more preferably 5% by mass or less, and still more preferably 4.5% by mass or less. The concentration of the component (c) is preferably 1% by mass or more, more preferably 2% by mass or more, further preferably 3% by mass or more, and preferably 40% by mass or less, more preferably 30% by mass or less, still more preferably. It may be 25% by mass or less, and more preferably 20% by mass or less.

  Although the composition for dilution does not need to contain components other than (a) component, (b) component, and (c) component, it contains the other component which can be contained in the aqueous solution for biofilm removal. It doesn't matter. The water used for dilution is not particularly limited, and ion exchange water, reverse osmosis (RO) water, distilled water, tap water, or the like can be used.

  The aqueous solution for removing a biofilm can contain, as other optional components, components that are blended in a general cleaning agent or the like as long as the biofilm removing effect is not hindered. For example, a chelating agent, a hydrotrope agent, a dispersant, a pH adjuster, a viscosity adjuster, a fragrance, a colorant, an antioxidant, an antiseptic, and the like can be given.

<Biofilm removal method>
In the biofilm removal method of this embodiment, an aqueous solution for biofilm removal is brought into contact with the biofilm. A biofilm is a polymer film formed outside the cells of microorganisms, and is formed by binding sugar chains such as polysaccharides and glycoproteins to each other. By bringing the aqueous solution for removing a biofilm of this embodiment into contact with the surface where the biofilm is present, the bonds between sugar chains in the biofilm can be dissociated. Thereby, a biofilm can be decomposed | disassembled and removed.

  When the ionic strength, salt concentration, etc. change greatly, the glycoprotein is denatured. When the glycoprotein is denatured, a stronger bond is formed in the biofilm, which may make it difficult to remove the biofilm. However, the biofilm removing aqueous solution of the present embodiment hardly induces such glycoprotein denaturation. For this reason, a biofilm can be removed efficiently.

  The biofilm removing aqueous solution and the biofilm may be contacted by any method as long as the biofilm to be removed comes into contact with the biofilm removing aqueous solution. For example, what is necessary is just to immerse the object which is going to remove a biofilm in the aqueous solution for biofilm removal. Rather than immersing the entire object in the aqueous biofilm removal solution, only part of the object is immersed in the aqueous biofilm removal solution so that the surface on which the biofilm is present is in contact with the aqueous biofilm removal solution. May be. Moreover, you may apply | coat or spray the aqueous solution for biofilm removal on the surface in which a biofilm exists. Further, an aqueous solution for removing biofilm is impregnated into a flexible water-absorbing material such as paper, cloth, and sponge, and the flexible water-absorbing material impregnated with the aqueous solution for removing biofilm is applied to the surface on which the biofilm is present. You may make it contact.

  The biofilm can be removed by standing in a state where the aqueous solution for removing the biofilm and the biofilm are in contact with each other, but heating may be performed to promote the removal. Furthermore, the surface on which the biofilm is present may be rubbed using a flexible water-absorbing material impregnated with the aqueous solution for removing the biofilm.

  The biofilm can be removed by the biofilm removal method of the present embodiment, and a microorganism suppressing agent such as a bactericide or a bacteriostatic agent can easily act on microorganisms forming the biofilm. For this reason, after removing a biofilm by the biofilm removal method of this embodiment, it is preferable to perform sterilization or sterilization of microorganisms using a microorganism suppressing agent. Moreover, if a microbial inhibitor that does not affect the action of the aqueous solution for removing a biofilm of the present embodiment is used, sterilization or sterilization can be performed simultaneously with the implementation of the biofilm removal method of the present embodiment. In this case, a biofilm removing aqueous solution and a microbial inhibitor may be mixed and used.

  The target for removing the biofilm is not particularly limited, and may be dishes such as dishes, chopsticks, and spoons, and cooking utensils such as cutting boards, kitchen knives, and bowls. The cooking utensils include cleaning tools such as sponges. Moreover, it can also be used for food processing equipment such as a noodle making machine, a rice cooking line, a conveyor, a cutter, and a slicer. Furthermore, it can also be used for removal of biofilms in medical devices such as tweezers, scalpels, forceps, tongue depressors, and dental instruments, and medical devices such as endoscopes.

-Evaluation method-
<PH>
The pH of the cleaning composition was measured with a pH measuring device using a glass electrode (HORIBA: PHMETER F-22). The sample temperature was 20 ° C. during the measurement.

<Biofilm removability>
A polyethylene test piece (manufactured by Nippon Test Panel Co., Ltd .: standard test version PE (with double-sided protective tape)) was cut out so that the bottom surface was a 1.5 cm × 1.5 cm square. 200 test pieces cut out were immersed in 100 mL of an aqueous solution of sodium hypochlorite having an effective chlorine concentration of 0.1% for 1 hour at a liquid temperature of 25 ° C., rinsed with 200 mL of ion-exchanged water, and dried at 25 ° C. for 1 hour. Then, after immersing the test piece in 100 mL of ethanol at a liquid temperature of 25 ° C. for 30 minutes, the test piece was dried at 25 ° C. for 1 hour and sterilized and washed to obtain test piece A.

  One test piece A was set in each well of a 24-well plate (Falcon). MTC2 medium (manufactured by Becton Dickinson) mixed with 1% Pseudomonasa eruginosa dispersion in physiological saline, adjusted to have an absorbance (OD) of 1 1 mL of the prepared bacterial solution was added to each well in which the test piece was set and cultured at 25 ° C. for 2 days to form a biofilm on the test piece. After discarding the bacterial solution, washing with 2 mL of ion-exchanged water for 3 minutes and disposal of the washing solution were repeated three times to obtain test piece B on which a biofilm was formed.

  One test piece B is set in each well of a 24-well plate prepared separately, and 2 mL of a sample solution obtained by diluting the detergent composition with ion exchange water 20 times is added to each well, and the test piece B is placed for 10 minutes. Soaked. Thereafter, each cleaning composition was discarded, and washing with 2 mL of ion exchange water for 3 minutes and disposal of the cleaning liquid (water) were repeated three times. Subsequently, 2 mL of 0.3% by mass of crystal violet solution (Wako Pure Chemical Industries, Ltd.) was added to each well, and the test piece was immersed for 90 minutes for staining. Next, the crystal violet solution was discarded, and washing with 2 mL of ion-exchanged water for 3 minutes and disposal of the cleaning solution (water) were repeated twice. One washed test piece B was set in each well of a 24-well plate prepared separately, and 2 mL of ethanol was added to each well. Test piece B was immersed in ethanol at 25 ° C. for 12 hours to dissolve crystal violet in ethanol, and then the absorbance of this ethanol was measured to obtain sample absorbance As. Moreover, it replaced with the sample solution and performed the same measurement using water, and set it as negative control light absorbency An.

  Based on the sample absorbance As and the negative control absorbance An, the biofilm removal rate (%) was calculated by the following formula.

  Biofilm removal rate (%) = ((An−As) / An) × 100

-Aqueous solution for biofilm removal-
<(A) component>
The following compounds were used as the component (a).
GE-2EH: 2-ethylhexyl glyceryl ether: compound synthesized by the following method [the content of the polyaddition compound of component (a3) was 1% by mass or less as a result of analysis by gas chromatography. ]

<Synthesis Method of 2-Ethylhexyl Glyceryl Ether>
9.57 g of acetic acid (manufactured by Kishida Chemical Co., Ltd .; primary, purity 99% or higher), 150 g of 2-ethylhexyl glycidyl ether (manufactured by Shell Japan, purity 99%), 28.44 g of ion-exchanged water, and sodium hydroxide (Wako Pure) Yakuhin Kogyo Co., Ltd. (special grade, purity 95%) 6.61 g was charged all at once into a 300 mL round bottom flask and stirred and held at 300 rpm with a crescent moon blade (width 4 cm, height 1.6 cm) to give 2-ethylhexyl. Glyceryl ether was obtained. The reaction was completed when the conversion reached 99% by quantitative analysis by gas chromatography.

<(B) component>
The following compounds were used as the component (b).
MGDA: methyl glycine diacetic acid trisodium salt, manufactured by BASF (trade name “TrilonM Compactate”), an aqueous solution with an effective content of 40% by mass, Table 1 shows the contents of methyl glycine diacetic acid trisodium salt did.

<(C) component>
As the component (c), the following compounds were mixed and used.
· Alkylglycoside: Formula (1) In R ¹¹ is a lauryl group, m1 is 0, G group is derived from glucose, condensation degree t of glucose 1.3 alkylglycoside surfactant-AO: N-lauryl -N, N-dimethylamine oxide

<(D) component>
The following compounds were used as the component (d).
Betaine: N-lauryl-N, N-dimethyl-N- (2-hydroxy-3-sulfopropyl) ammonium sulfobetaine

-Examples and Comparative Examples-
Example 1
(A) Component GE-2EH 0.043% by mass, (b) Component MGDA 0.03% by mass, Component (c) Alkyl glycoside 0.22% by mass and AO 0.08% by mass, d) An aqueous solution for biofilm removal containing 0.015% by mass of betaine and water was prepared, and the biofilm removal rate was evaluated. The amount of each component contained in the aqueous solution for removing a biofilm is the amount of each active component. The mass ratio (a) / (b) between the mass of the component (a) and the mass of the component (b) is 1.43. The pH was 6.6 and the biofilm removal rate was 60%.

(Comparative Example 1)
(A) Without component, (b) component MGDA 0.03% by mass, (c) component alkylglycoside 0.22% by mass and AO 0.08% by mass, (d) component betaine 0 An aqueous solution for removing biofilm containing 0.15% by mass and water was prepared, and the biofilm removal rate was evaluated. The amount of each component contained in the aqueous solution for removing a biofilm is the amount of each active component. The pH was 6.6 and the biofilm removal rate was 10%.

(Comparative Example 2)
(B) Component not included, (a) Component GE-2EH 0.043% by mass, (c) Component alkylglycoside 0.22% by mass and AO 0.08% by mass, (d) Component An aqueous solution for removing biofilm containing 0.015% by mass of betaine and water was prepared, and the biofilm removal rate was evaluated. The amount of each component contained in the aqueous solution for removing a biofilm is the amount of each active component. The pH was 6.6 and the biofilm removal rate was 0%.

(Comparative Example 3)
(A) GE-2EH as component 0.043% by mass, (b) component MGDA 0.03% by mass, (c) component alkylglycoside 0.08% by mass and AO 0.08% by mass , (D) A biofilm removal aqueous solution containing 0.015% by mass of betaine and water was prepared, and the biofilm removal rate was evaluated. The concentration of each component of the aqueous solution for removing a biofilm is the concentration of each active component. The mass ratio (a) / (b) between the mass of the component (a) and the mass of the component (b) is 1.43. The pH was 6.6 and the biofilm removal rate was 15%.

  Table 1 summarizes each example and comparative example. As shown in Table 1, when a predetermined amount of the A component, the B component, and the C component was included, excellent biofilm removability was exhibited.

  Using the components shown in Table 2, a biofilm removing aqueous solution was prepared in the same manner as in the Examples.

Claims (8)

(A) 0.005 mass% or more and 0.5 mass% or less of 2-ethylhexyl glyceryl ether as a component,
(B) 0.005% by mass or more and 0.5% by mass or less of methylglycine-N, N-diacetic acid or a salt thereof as a component;
(C) The biofilm removal method which makes the surface which a biofilm exists contact the aqueous solution for biofilm removal containing 0.2 to 2 mass% of nonionic solubilizers as a component.   The biofilm removal according to claim 1, wherein a mass ratio (a) / (b) of the mass of the component (a) to the mass of the component (b) in the aqueous solution for removing a biofilm is 1 or more and 3 or less. Method.   The biofilm removal method according to claim 1 or 2, wherein the component (c) is at least one selected from alkylglycoside surfactants and amine oxide surfactants.   The said biofilm removal aqueous solution is a biofilm removal method of any one of Claims 1-3 containing a betaine type surfactant as (d) component.   The biofilm removal method of any one of Claims 1-4 whose content of the anionic surfactant in the said aqueous solution for biofilm removal is 0.001 mass% or less.   The biofilm removal method according to any one of claims 1 to 5, wherein the surface on which the biofilm is present is rubbed with a flexible water-absorbing material impregnated with the aqueous solution for biofilm removal.   The biofilm removal method according to any one of claims 1 to 5, wherein an object having a surface on which a biofilm is present is immersed in the aqueous solution for biofilm removal. The aqueous solution for removing a biofilm is a composition for dilution containing the component (a), the component (b), and the component (c). Diluted to produce
The content of the component (a) in the dilution composition is 0.5% by mass or more and 10% by mass or less, and the content of the component (b) is 0.5% by mass or more and 10% by mass or less. The biofilm removal method according to any one of claims 1 to 7.