JP5166808B2 - Method for suppressing biofilm formation in washing machine - Google Patents

Description

  The present invention relates to a biofilm suppression method in a cleaning machine that prevents the generation of biofilm in the cleaning machine and prevents the growth of bacteria. More specifically, the present invention relates to a biofilm production suppressing method for suppressing the production of biofilms composed of microorganisms and microorganism-producing substances in a washing machine in which microbial contamination is a problem, and preventing harm resulting therefrom.

  A biofilm is also called a biofilm or slime, and generally refers to an aqueous system in which microorganisms adhere to and grow on the surface of substances to produce macromolecular substances such as polysaccharides and proteins from within microbial cells to form structures. . When a biofilm is formed, harms caused by microorganisms occur and cause problems in various industrial fields. For example, when a biofilm is formed in the piping of a food plant, the biofilm is peeled off and not only leads to contamination of foreign substances in the product, but also causes food poisoning due to microorganism-derived toxins. Furthermore, biofilm formation on the metal surface causes metal corrosion and promotes aging of the equipment. Furthermore, inside automatic washing machines that are washed with water-based washing machines such as automatic dishwashers and clothing washing machines, there are always plenty of dirt that is a nutrient source for the bacteria, and it is indispensable for the growth of bacteria. There are many scenes filled with moisture and moisture, and it is easily presumed that it is convenient for the production of biofilms. In fact, the occurrence of slime and bacteria adherence caused by biofilm generation inside the washing machine are likely to occur, and this is likely to cause problems in terms of washing and hygiene, such as adhesion and dropping of bacteria on the object to be washed.

  Furthermore, microbial control agents such as bactericides and bacteriostatic agents are not sufficiently effective against microbial aggregates that have formed biofilms, compared to microorganisms that are dispersed and suspended in water. There are also many. For example, in the medical field, many cases of nosocomial infections have been reported in recent years due to microorganisms remaining in narrow gaps and holes in medical devices to form biofilms. In the human oral cavity, it is well known that biofilms formed on teeth, so-called dental plaque (plaque), cause caries and periodontal disease, and these problems have been studied for a long time.

  Until now, in order to suppress biofilms, the idea of not allowing bacteria to grow by giving bactericidal or bacteriostatic action to microorganisms, particularly bacteria, has been generally studied. Patent Document 1 and Patent Document 2 disclose that the number of bacteria can be reduced using fatty acids, aliphatic alcohols, and the like, and as a result, adhesion of bacteria to the target substance can be prevented. In particular, Patent Document 1 shows that a composition prepared with an antibacterial oil phase and an emulsifier has an effect of reducing the number of bacteria in a relatively short time, which is based on the fact that the absolute number of bacteria per unit volume is low, It expresses the idea of suppressing the adhesion of bacteria to the surface of the target substance. Further, Patent Document 3 discloses a toothpaste composition in which a non-aqueous active ingredient such as an anti-inflammatory agent is dissolved in an oily substance, but does not suppress biofilm formation.

  Patent Document 1 or 2 describes the evaluation of bactericidal properties (reducing the number of bacteria by about the fourth power) when microorganisms are sterilized for a relatively short time within 60 minutes or contacted with an antibacterial composition. However, the biofilm problem occurs in units of a long time of several days to several months, and it is practically difficult to link to biofilm production suppression control with a short sterilization evaluation. Fatty acids and fatty alcohols listed as antibacterial oil phases do not have a sufficient bactericidal effect on all microorganisms (bacteria), especially gram-negative bacteria that often cause problems by forming biofilms In contrast, it does not have the minimum inhibitory concentration (MIC), which is an indicator of the bactericidal effect over a long period of time (Science of preservatives and fungicides; edited by John J. Kabbalah, Fragrance Journal, 1990 ). Furthermore, according to experiments by the inventors, the composition described in Patent Document 1 or 2 shows a short-term (up to about 3 hours) bactericidal effect against Pseudomonas aeruginosa and Serratia bacteria among gram-negative bacteria. However, in the long-term (one day or more), it was confirmed that the biofilm was formed as a result without showing bactericidal effect or even bacteriostatic effect to suppress bacterial growth.

In addition, there are high bactericidal bactericides such as cationic surfactants and hypochlorites with high bactericidal properties, but if organic substances are present in the system, bactericidal properties are quickly lost. As described above, it is difficult to maintain the effect of reducing the number of bacteria over a long period of time.
For these reasons, it has been difficult to fundamentally suppress the production of biofilms from the viewpoint of bactericidal and bacteriostatic.
Special Table 2002-524257 JP-T-2004-513153 JP 2005-289917 A

  Accordingly, an object of the present invention is to provide a biofilm production suppression method in a washing machine that prevents the production of biofilm in a washing machine in which microbial contamination is a problem and prevents the growth of fungi and mold.

  Therefore, the present inventor has made various studies on methods for suppressing biofilms in a cleaning machine, and found that a method using a composition containing the compound (A) described later can suppress the production of biofilms in the cleaning machine. It came to complete.

That is, the present invention relates to the general formula (1)
RO- (EO) n-H (1)
(Wherein R represents a linear or branched alkyl or alkenyl group having 8 to 14 carbon atoms, EO represents an ethyleneoxy group, and n represents an integer of 0 to 5). A composition containing at least one selected from (A) is brought into contact with a washing machine that is washed with an aqueous washing solution, and a method for suppressing biofilm production in the washing machine is provided.

In addition, the present invention provides a general formula (1)
RO- (EO) n-H (1)
(Wherein R represents a linear or branched alkyl or alkenyl group having 8 to 14 carbon atoms, EO represents an ethyleneoxy group, and n represents an integer of 0 to 5). The present invention provides a biofilm production inhibitor composition for use in a cleaning machine, which contains one or more selected from (A) and is used by being brought into contact with a cleaning machine that is cleaned with an aqueous cleaning solution.

  ADVANTAGE OF THE INVENTION According to this invention, the production | generation of the biofilm in the washing machine in which microbial contamination becomes a problem can be prevented, and the proliferation of a microbe and a mold can be prevented.

The active ingredient (A) of the biofilm inhibitor composition in the washing machine of the present invention has the general formula (1):
RO- (EO) n-H (1)
Wherein R is a linear or branched alkyl or alkenyl group having 8 to 14 carbon atoms, EO is an ethyleneoxy group, and n is an integer of 0 to 5.

  The alkyl group or alkenyl group represented by R may be a straight chain or a branched chain, but those having 10 to 12 carbon atoms are preferred from the viewpoint of the biofilm formation inhibitory effect. The number n of ethyleneoxy groups represented by EO is more preferably 0-4, and still more preferably 1-3.

  In the present invention, the compound (A) may be present in the system at a concentration of 10 ppm or more as a concentration capable of exhibiting the biofilm formation inhibitory effect. It is preferable to make it contact, and 10-1000 ppm is more preferable.

  As described above, the composition used in the biofilm production suppression method in the cleaning machine of the present invention only needs to contain 10 to 10,000 ppm of the compound (A) as the concentration at the time of use, so the concentration of the compound (A) in the composition Is not particularly limited, but is preferably 0.001 to 50% by weight, more preferably 0.01 to 10% by weight, and still more preferably 0.01 to 1% by weight from the viewpoints of economy and effects.

In the present invention, the compound (A) may be used as an aqueous solution, may be used as an emulsifying system using a surfactant, or may be used as an organic solvent solution using an organic solvent. When EO of 0) is 0, it is preferably used as an organic solvent solution using an organic solvent.
Examples of the organic solvent used here include ethanol, 1-propanol, 2-propanol, ethylene glycol, diethylene glycol, low molecular weight polyethylene glycol, ethylene glycol-n-monobutyl ether, diethylene glycol mono-n-butyl ether, propylene glycol as alcohols. Dipropylene glycol, low molecular weight polypropylene glycol, glycerin, diglycerin, polyglycerin, etc. are mentioned, among others, ethanol, 1-propanol, 2-propanol, low molecular weight polyethylene glycol, diethylene glycol mono-n-butyl ether, propylene glycol, dipropylene glycol Is preferred. Examples of hydrocarbons include hexane, octane, liquid paraffin, cyclohexane, and benzene. Examples of the esters include methyl acetate, ethyl acetate, methyl octoate, and animal and plant-derived fats and oils. Furthermore, examples of the polar aprotic solvent include dimethyl sulfoxide and N, N-dimethylformamide. Among them, dimethyl sulfoxide is preferable.

  Although the kind of surfactant for making this invention composition into an emulsion type is not specifically limited, Surfactant which can make compound (A) exist stably in an aqueous system is desirable. Furthermore, from the viewpoint of emulsification / dispersion / solubilization performance, it is preferable to use an anionic surfactant or a nonionic surfactant among the surfactants.

  Examples of the anionic surfactant include lignin sulfonate, alkylbenzene sulfonate, alkyl sulfonate, polyoxyethylene (hereinafter referred to as POE) alkyl sulfonate, POE alkylphenyl ether sulfonate, and POE alkylphenyl. Ether phosphate ester salt, POE aryl phenyl ether sulfonate, alkyl sulfate ester salt, POE alkyl sulfate ester salt, POE aryl phenyl ether phosphate ester salt, naphthalene sulfonate, naphthalene sulfonate formalin condensate, POE tribenzyl phenyl Ether sulfonate, alkyl phosphate, POE alkyl phosphate, POE tribenzylphenyl ether phosphate ester salt, dialkyl sulfosuccinate, fatty acid salt (soap), POE Al Ether acetates, and among them alkyl sulfates and POE alkyl sulfates, it is more preferable to use a POE alkyl ether acetic acid salt. These anionic surfactants preferably have 10 to 18 alkyl carbon atoms, and the ethylene oxide average addition mole number is preferably 0 to 10, and more preferably 0 to 5.

  Nonionic surfactants include POE alkyl ethers (excluding compound (A)), POE alkyl phenyl ethers, polyoxypropylene / POE (block or random) alkyl ethers, POE aryl phenyl ethers, POE styrenated phenyls. Monovalent alcohol derivative type nonionic surfactants such as ether and POE tribenzylphenyl ether, polyhydric alcohols such as (poly) glycerin fatty acid ester, sucrose fatty acid ester, sorbitan fatty acid ester, POE sorbitan fatty acid ester, alkyl polyglycoside Derivative-type nonionic surfactants, etc. are mentioned. Among them, POE alkyl ether (except for compound (A)), (poly) glycerin fatty acid ester, alkyl polyglycoside, sorbitan fatty acid ester Preferably POE sorbitan fatty acid ester, further, POE alkyl ethers [except the compound (A)] is preferred. Of these, the HLB of the POE alkyl ether is more preferably 10 or more. The POE alkyl ether preferably has 12 to 18 alkyl carbon atoms, and more preferably has an ethylene oxide average addition mole number of 6 or more.

  Surfactants can be used alone or in combination of two or more in order to enhance the emulsification / dispersion / solubilization performance.

  The weight ratio [(A) / surfactant] of the compound (A) and the surfactant in the emulsified composition is preferably 2 or less from the viewpoint of a long-term biofilm suppressing effect, and preferably 2/1 to 1/100. More preferably, 2/1 to 1/50 is more preferable, 2/1 to 1/20 is still more preferable, and 1/1 to 1/10 is still more preferable.

  In the present invention, it is also possible to use a bactericide and an antibacterial agent together with the compound (A). In general, when a biofilm is formed, a situation occurs in which the bactericidal agent is hardly effective. However, when the formation of the biofilm is suppressed by the compound (A), it is possible to sufficiently bring out the efficacy of the bactericide.

  The above bactericides and antibacterials include benzalkonium chloride, benzethonium chloride, didecyldimethylammonium chloride, cetylpyridinium chloride, chlorhexidine hydrochloride, chlorhexidine gluconate, polyhexamethylenebiguanidine hydrochloride, triclosan, isopropyl Examples include methylphenol, trichlorocarbanilide, ethanol, isopropyl alcohol and the like.

  In the composition used for the biofilm production suppression method in the washing machine of the present invention, a thickener can be used in order to increase the viscosity and improve the adhesion to an object.

  Further, a chelating agent may be added to the composition. Examples of the chelating agent include ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic acid (NTA), succinic acid, salicylic acid, oxalic acid, malic acid, lactic acid, fumaric acid, tartaric acid, citric acid, gluconic acid, tripolyphosphoric acid, 1-hydroxy Examples include ethane-1,1-diphosphonic acid, polyacrylic acid, acrylic acid / maleic acid copolymer, and salts thereof.

Further, the composition can take various forms such as paste, powder, tablet and the like in addition to liquid. The biofilm inhibitor composition may be a one-component type in which all the components are mixed, but depending on ease of use, it may be divided into several divided packages.
As described above, the composition of the present invention may be any one of an aqueous solution system, an organic solvent solution system, and an emulsification system, but it is more effective to use the composition in an aqueous solution system.

The biofilm production suppression method in a washing machine of the present invention is characterized in that a composition containing the compound (A) is brought into contact with an object, that is, in the washing machine. Examples of this method include a method in which the compound (A) is first contained in a rinsing liquid and rinsed with this rinsing liquid. According to this method, it is not necessary to apply in the washing machine, and it is simple. And it is preferable from the point of the biofilm production | generation suppression effect to leave as it is after this rinsing. Moreover, the method of filling a compound (A) containing composition in a washing machine is also mentioned. Furthermore, the method of spraying the compound (A) -containing composition by spraying mist into a washing machine using a spray device, spraying a foamed product using a foaming machine, or brushing is also included. In addition, a towel may be impregnated with the aqueous solution to wipe off the object. If the conditions for contact with the object are satisfied, an aqueous solution of the compound (A) can be attached or applied to the surface where the biofilm can exist. In the above, the contact between the composition containing the compound (A) and the object is preferably performed continuously. Here, performing continuously is applied so that the composition containing the compound (A) remains on the object as described above, and the composition containing the compound (A) and the object are long. It means making contact with time. That is, it is preferable not to wash away the composition after application to the object.
Moreover, it is also possible to spread in the form of cream or ointment without using a water dilution system. In this case, the compound (A) is provided in a form dissolved, dispersed, and emulsified in an appropriate medium. In the above, the contact between the composition containing the compound (A) and the object is preferably performed continuously. Here, performing continuously is applied so that the composition containing the compound (A) remains on the object as described above, and the composition containing the compound (A) and the object are long. It means making contact with time. That is, it is preferable to leave the composition without washing after application to the object. The standing time is not particularly limited, but is preferably 3 to 120 hours, more preferably 6 to 100 hours, and further preferably 12 to 72 hours.

  The washing machine that is the subject of the present invention is not limited as long as it is a washing machine that is washed with an aqueous washing liquid, but an automatic washing machine that is washed with an aqueous washing liquid, such as an automatic dishwashing machine, a clothing washing machine, a medical instrument washing machine, Examples include a washing machine for plastic containers.

Component (A) R1O- (EO) p-H used in this example
(A-1) C12 alcohol [Calcoal 2098, manufactured by Kao Corporation, R1 = C12 alkyl, p = 0]
(A-2) C12 alcohol ethylene oxide 3 mol adduct [NIKKOL BL-3SY, manufactured by Nikko Chemicals, R1 = C12 alkyl, p = 3]
Component (A ′) R1′O— (EO) p—H
(A′-1) C18 alcohol [Calcoal 8098, manufactured by Kao Corporation, R1 ′ = C18 alkyl, p = 0]
(A′-2) C12 alcohol ethylene oxide 8 mol adduct [NIKKOL BL-8SY, manufactured by Nikko Chemicals, R1 ′ = C12 alkyl, p = 8]

Surfactant [Numbers in parentheses indicate the average number of moles of ethylene oxide added. ]
(Nonionic surfactant 1)
Polyoxyethylene (12) lauryl ether [Emulgen 120, manufactured by Kao Corporation]
(Nonionic surfactant 2)
Lauryl glycoside [Mydol 12, manufactured by Kao Corporation]
(Anionic surfactant 1)
Sodium lauryl sulfate [Emar 0, manufactured by Kao Corporation]

Example 1
(Addition to rinse water)
A base detergent (sodium carbonate 70% by weight / sodium metasilicate 20% by weight / sodium tripolyphosphate 10% by weight) is prepared in a washing tank (38L) of a commercial dishwasher [SANYO DR53 manufactured by Sanyo Electric Co., Ltd.] 38 g of this was added and dissolved in hot water at 50 ° C. Set 4 pieces of 8 ounce glass coated with model dirt (1 g of rapeseed oil and 1 g of milk) on a dedicated rack, wash with 50 ° C cleaning solution for 40 seconds, and then use the specified amount of dishwasher shown in Table 1 Rinse was performed for 8 seconds using 4 L of 40 ° C. rinse water in which the finish composition was dissolved or stirred and dispersed.
Each time model dirt is put into the washing tank, and washed once every hour for 5 times a day, rinsed for 20 hours until the next day, and it is repeated for 10 days until the biofilm formation in the machine washer is visually observed. Observed. The biofilm production state is indicated as “◯” when no biofilm is produced, “Δ” when the biofilm starts to be slightly colored, and “x” when the biofilm is clearly produced.
The results are shown in Table 1.

Example 2 (spray in washing tank)
In the same manner as described above, the base cleaning agent was washed with a cleaning solution at 50 ° C. for 40 seconds, and then rinsed with 4 L of 40 ° C. rinsing water for 8 seconds. Each time, the model soil was put in a washing tank and washed and rinsed 5 times a day every other hour. Thereafter, the dissolved or stirred and dispersed agent shown in Table 2 was sprayed evenly in the tank, and then left for 20 hours until the next day, which was repeated for 10 days, and the biofilm formation in the machine washer was visually observed. The biofilm production state is indicated as “◯” when no biofilm is produced, “Δ” when the biofilm starts to be slightly colored, and “x” when the biofilm is clearly produced.
The results are shown in Table 2.

Example 3 Effect of washing machine for clothing (full tank)
Fill the washing tank of a commercial clothes washing machine [LAVNET EXCELA 22N manufactured by Inamoto Seisakusho Ltd.] with a high water level (about 190 L). Further, an empty operation for 5 minutes was performed, and this was repeated for 7 days. After the final drainage, biofilm formation in the clothing washing machine was visually observed. The biofilm production state is indicated as “◯” when no biofilm is produced, “Δ” when the biofilm starts to be slightly colored, and “x” when the biofilm is clearly produced.
The results are shown in Table 3.

  According to the method of the present invention, it was confirmed that the biofilm production in the clothing washing machine can be remarkably suppressed.

Claims (9)

General formula (1)
RO- (EO) n-H (1)
(Wherein R represents a linear or branched alkyl or alkenyl group having 8 to 14 carbon atoms, EO represents an ethyleneoxy group, and n represents an integer of 0 to 5). A method for inhibiting biofilm formation in a washing machine, comprising bringing a composition containing one or more selected from (A) into a washing machine that is washed with an aqueous cleaning liquid.   The method for inhibiting biofilm production according to claim 1, wherein the concentration of the compound (A) during use of the composition is 10 to 10,000 ppm.   The biofilm production suppressing method according to claim 1 or 2, wherein the washing machine is an automatic dishwashing machine or a clothing washing machine.   The biofilm production suppression method according to any one of claims 1 to 3, wherein the composition is an aqueous solution or an organic solvent solution.   The biofilm production | generation suppression method of any one of Claims 1-4 with which a contact is performed continuously.   The biofilm production suppression according to any one of claims 1 to 5, wherein the contact is to apply, spray or fill the composition in the washing machine and leave the composition, or to rinse the washing machine with the composition. Method. General formula (1)
RO- (EO) n-H (1)
(Wherein R represents a linear or branched alkyl or alkenyl group having 8 to 14 carbon atoms, EO represents an ethyleneoxy group, and n represents an integer of 0 to 5). A biofilm production inhibitor composition for use in a cleaning machine, comprising one or more selected from (A) and used in contact with a cleaning machine that is cleaned with an aqueous cleaning solution.   The biofilm production inhibitor composition according to claim 7, wherein the concentration of the compound (A) when the composition is used is 10 to 10,000 ppm.   The biofilm production inhibitor composition according to claim 7 or 8, wherein the composition is an aqueous solution or an organic solvent solution.