KR20060106688A - Industrial antimicrobial compositions and antimicrobial methods - Google Patents

Abstract

Provided are industrial antimicrobial compositions and antimicrobial methods having high safety and antimicrobial activity and exhibiting sufficient antimicrobial activity, even in alkaline conditions. As an active ingredient, it is an industrial antimicrobial composition containing sodium pyrithione and 2-methyl-4-isothiazolin-3-one and used under alkaline conditions of pH 7 or more. In particular, it is preferable to use sodium pyrthione and 2-methyl-4-isothiazolin-3-one in water to make an aqueous solution having an alkaline pH of 9-11.

Antimicrobial compositions, antibacterial methods, sodium pyridionone, 2-methyl-4-isothiazolin-3-one

Description

Antimicrobial composition for industrial use and antibacterial treatment method

1 is a graph showing the performance test results of the industrial antimicrobial composition of the present invention.

2 is a graph showing the performance test results of the industrial antimicrobial composition of the present invention.

The present invention relates to an industrial antimicrobial composition comprising at least two kinds of substances as an active ingredient and an antimicrobial method using the industrial antimicrobial composition.

As a conventional industrial antimicrobial composition, 2,2-dibromo-3-nitrilopropionamide (hereinafter referred to as DBNPA) and 1,4-bis (bromoacetoxy) -2-butene (hereinafter referred to as BBAB) And 5-chloro-2-methyl-4-isothiazolin-3-one (hereinafter referred to as CL-MIT) are used. These substances show excellent antibacterial effect in neutral to acidic acid, but decompose well in alkaline.

On the other hand, 1,2-benzoisothiazolin-3-one (hereinafter referred to as BIT), triazine and sodium pyrithione (hereinafter referred to as NaPT), which are similarly used as industrial antimicrobial compositions, are stable in alkali. However, when BIT has a pH of 9 or more, there is a problem that the antimicrobial activity is greatly reduced due to structural change, and triazine releases formalin. Moreover, NaPT alone has a problem of low antibacterial effect.

Therefore, the industrial antimicrobial composition which raised antimicrobial power by combining two or three types of substances is proposed (for example, patent document 1). In patent document 1, the industrial antimicrobial composition which combined 4, 5- cyclo- n-octyl-4-isothiazolin-3-one (henceforth DCOIT), and NaPT is disclosed. The industrial antimicrobial composition disclosed in Patent Document 1 exhibits high antibacterial activity even at low concentrations as the NaPT and isothiazoline-3-one compounds exhibit synergistic effects.

However, DCOIT is not soluble in water. For this reason, when using a substance which does not dissolve in water such as DCOIT, an organic solvent must be used. When a solvent-type product dissolved in an organic solvent is applied to an aqueous emulsion such as latex, an emulsion shock is caused by the solvent to aggregate. For this reason, in many cases, the product using the organic solvent is difficult to apply. For this reason, when the application target is aqueous, it is preferable that the antimicrobial composition is also aqueous.

By the way, in the material used for the industrial antimicrobial composition, the antimicrobial effect and safety are incompatible, and the material excellent in antimicrobial power tends to have a problem in safety, such as having mutagenicity. For example, it is known that among the isothiazolin-3-one compounds, CL-MIT has a high antibacterial effect, but there is a safety problem that is mutagenic or prone to allergy, and 2-methyl-4-isothiazoline -3-one (hereinafter referred to as MIT) has high safety but lower antibacterial effect than CL-MIT.

In addition, since MIT is unstable when used as an aqueous formulation, a stabilizer is required to obtain a stable aqueous formulation over a long period of time (Patent Document 2).

Japanese Patent Application Laid-Open No. 2003-63916

Japanese Patent Application Laid-Open No. 3-188071

In view of the above problems, an object of the present invention is to provide an industrial antimicrobial composition and an antimicrobial method having high safety and antimicrobial activity, particularly exhibiting sufficient antimicrobial activity under alkaline conditions and not causing aggregation.

By combining MIT with low antibacterial effect alone with NaPT, the inventors of the present invention have a high antibacterial effect by synergistic effects under alkaline conditions. Especially, an aqueous liquid solution in which MIT and NaPT are dissolved in water is alkaline even without using a stabilizer. The solution was found to be stable for a long time and exhibit a high antimicrobial effect, completing the present invention. Specifically, the present invention provides the following.

(1) An industrial antimicrobial composition comprising sodium pyrithione and 2-methyl-4-isothiazolin-3-one and added to an alkaline antibacterial target solution of pH 7 or higher.

(2) An industrial antimicrobial composition wherein sodium pyridion and 2-methyl-4-isothiazolin-3-one are dissolved in a solvent containing water to prepare an aqueous liquid formulation having a pH of 7 or more.

(3) The industrial antimicrobial composition as described in (1) or (2) whose pH is 9-11.

(4) The industrial use according to any one of (1) to (3), wherein the sodium pyridion and the 2-methyl-4-isothiazolin-3-one are included in a weight ratio of 4: 1 to 1: 4. Antimicrobial composition.

(5) An antibacterial method of adding sodium pyrithione and 2-methyl-4-isothiazolin-3-one to an alkaline antibacterial solution having a pH of 7 or higher.

(6) The sodium pyrithione and the 2-methyl-4-isothiazolin-3-one are dissolved in a solvent containing water and added to the alkaline antibacterial target liquid as an aqueous solution having a pH of 7 or more. The antimicrobial method of description.

(7) The antimicrobial method according to (5), wherein the sodium pyridion and the 2-methyl-4-isothiazolin-3-one are separately added to the alkaline antibacterial target liquid.

(8) The antimicrobial method according to any one of (5) to (7), wherein the alkaline antibacterial target liquid has a pH of 9-11.

(9) (5) to (8), wherein the sodium pyrithione and the 2-methyl-4-isothiazolin-3-one are added to the alkaline antibacterial solution in a ratio of 4: 1 to 1: 4 by weight. The antibacterial method according to any one of the above.

(1) The industrial antimicrobial composition which concerns on invention of a base material is added to alkaline liquid of pH 7 or more, especially pH 9-11. In the present specification, the 'liquid' is to include a suspension (slurry). Specific examples of the alkaline antibacterial target liquid include alkali slurry containing calcium carbonate, clay, kaolin or bentonite, coating liquid, aqueous coating, latex emulsion, polymer emulsion, metal covalent sharing, Fiber emulsions, thickened polysaccharides, adhesives and the like.

By coexisting sodium pyridion (NaPT) and 2-methyl-4-isothiazolin-3-one (MIT) in alkaline conditions, decomposition of MIT, which is susceptible to decomposition in aqueous conditions, can be suppressed and a synergistic effect can be obtained. For this reason, when NaPT and MIT are used in alkaline conditions, bacterial growth in an antibacterial solution can be suppressed over a long period of time at low concentrations compared to when NaPT or MIT is used alone.

The industrial antimicrobial composition may be added to the antibacterial target liquid as an agent in any form, such as a liquid, powder, emulsifier, and flow agent. NaPT and MIT may be formulated separately or may be formulated by mixing. The solvent used in the formulation is not particularly limited, and either a polar solvent or a nonpolar solvent may be used. Specific examples of the polar solvent include water, an alcohol solvent, a glycol solvent, and a glycol ether solvent. Examples of the nonpolar solvent include toluene, paraffin, xylene, vegetable oil, and the like.

It is particularly preferable to use water as the solvent, and specifically, NaPT and MIT are dissolved in a solvent containing water as in the invention described in (2), and the pH is 7 or more, preferably in the pH as in the invention described in (3). It is preferable to make it into the aqueous liquid agent made into 9-11. The pH of the aqueous liquid agent can be adjusted by dissolving NaPT and MIT in water and then adding alkalis such as sodium hydroxide, potassium hydroxide, ammonia, calcium hydroxide and sodium carbonate or organic acids such as hydrochloric acid and sulfuric acid such as sulfuric acid.

The solvent may contain additives such as a surfactant and a stabilizer, but it is preferable that the solvent is substantially free of an organic solvent containing 50% by weight or more of water. The surfactant and stabilizer added to the solvent are not particularly limited. Specific examples of the surfactant include anionic surfactants such as metal salts of alkylbenzenesulfonic acid and alkylnaphthalenesulfonic acid, nonionic surfactants such as polyoxyethylene alkylphenyl ether and polyoxyethylenenonylphenyl ether, and cationic interface such as aliphatic amine salts. Amphoteric surfactants, such as an active agent and an amino carbonate, are mentioned. Moreover, an alkali metal nitrate salt etc. are mentioned as a stabilizer.

When adding surfactant, it is preferable that the addition density | concentration is 0.1-10 weight% with respect to a solvent. In addition, it is preferable that the total concentration of the additive having no antimicrobial activity such as a surfactant and a stabilizer is less than 2% by weight.

By dissolving NaPT and MIT in a solvent containing water to make it alkaline, a high antibacterial effect due to the synergistic effect of these two components can be obtained and the decomposition of MIT can be suppressed. For this reason, alkaline aqueous formulations containing NaPT and MIT can exhibit stable antibacterial effects for a long time. In addition, since the aqueous liquid agent does not contain an organic solvent, it can be manufactured at low cost, has a low burden on the human body and the environment, and when added to latex and a coating liquid, it has good compatibility and can prevent emulsion aggregation.

The aqueous liquid formulation contains NaPT in a concentration of 5 to 40% by weight and MIT in a concentration of 10 to 40% by weight, and the mixing ratio of both is in the range specified in the invention described in (4), that is, NaPT: MIT is 4: 1 to the weight ratio. It is preferable that it is 1: 4.

In the case of carrying out the antimicrobial method described in (5), wherein the industrial composition according to the present invention is added to the alkaline antimicrobial target solution, the NaPT concentration is 1 to 1,000 mg / L and the MIT concentration is 1 to 1,000 mg. It is preferable to use NaPT and MIT in a weight ratio of 4: 1 to 1: 4 in / L. NaPT and MIT may be separately formulated as in the invention described in (7) to be added alternately into the antimicrobial target solution, or (6) may be added to the antimicrobial target solution in a state in which both are mixed in advance. . NaPT and MIT may be used under alkaline conditions to adjust the pH of the antimicrobial target liquid by adding alkali to the antimicrobial target liquid as needed, or may be used as NaPT and MIT are dissolved in an alkaline solvent in advance.

To practice the invention  Best form for

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail based on an Example.

[Antibacterial Test]

In order to evaluate the antimicrobial activity of the industrial antimicrobial composition according to the present invention, performance tests 1 to 12 were performed. As an industrial composition, an aqueous solution of 45% NaPT and an aqueous solution of 50% MIT were used alone or in combination. The antimicrobial activity was evaluated by adding this industrial composition to the culture medium to which bacteria were cultured, changing the concentration, and obtaining the minimum growth inhibitory concentration. As test bacteria, Porphyrobacter sp. Isolated from a calcium carbonate slurry and Pseudomonas pseudoalcaligenens isolated from a color coating solution were used. As the medium, a mixed liquid medium (pH 9, hereinafter referred to as 'PY medium') of polypeptone and yeast extract was used. The cell concentration in the medium at the start of the test was 4.5 × 10 ⁵ cells / ml in the test using Porphyrobacter sp. And 1.1 × 10 ⁶ cells / ml in the test using Pseudomonas pseudoalcaligenens.

In performance tests 1-6, Porphyrobacter sp. Was used as test bacteria, and in performance tests 7-12, Pseudomonas pseudoalcaligenens was used as test bacteria. The concentrations of NaPT and MIT added to the medium in the performance tests 1 to 6 are shown in Table 1, and the test results are shown in FIG. In addition, in the performance tests 7-12, the addition concentration of each of NaPT and MIT is shown in Table 2, and a result is shown in FIG.

NaPT concentration (mg / L) MIT concentration (mg / L) Test 1 10.5 0 Test 2 0.7 0.2 Test 3 0.6 0.3 Test 4 0.6 0.6 Test 5 0.2 0.5 Test 6 0 0.9

NaPT concentration (mg / L) MIT concentration (mg / L) Test 7 18 0 Test 8 3.5 One Exam 9 2.4 1.2 Exam 10 1.2 1.2 Exam 11 0.5 1.25 Test 12 0 1.8

1 and 2 are Porphyrobacter sp. When NaPT and MIT are used alone or in combination. Or, it is a graph showing the test result of binary growth inhibitory concentration showing the minimum growth inhibition concentration for Pseudomonas pseudoalcaligenens. Here, the effects of the antimicrobial agent used against microorganisms such as bacteria and fungi are roughly classified into bacteriostatic action that inhibits the growth of microorganisms and bactericidal action that kills microorganisms, and the minimum growth inhibition concentration is to evaluate the bacteriostatic action of the antimicrobial agent. . Specifically, with increasing the concentration of the antimicrobial agent, the effect of inhibiting the growth of the microorganism is increased, and the growth rate of the microorganism is lowered. The minimum growth inhibitory concentration is the minimum concentration of the antimicrobial agent necessary to stop the growth of the microorganism by increasing the concentration of the antimicrobial agent to the microorganism.

In these figures, the minimum growth inhibitory concentration when NaPT or MIT was used alone was plotted on the X and Y axes, respectively, and the minimum growth inhibition concentration of the industrial antimicrobial composition using NaPT and MIT was plotted on the coordinates. In addition, the minimum growth inhibitory concentration of the industrial antimicrobial composition using NaPT and MIT in combination is linearly connected to the minimum growth inhibitory concentration plotted on the X-axis or Y-axis when NaPT or MIT is used alone. In this case, an additive effect can be obtained, and when plotted below this straight line, a synergistic effect is shown. When plotted above this straight line, an antagonistic effect is shown.

As shown in Fig. 1, the results of Tests 2 to 5 using NaPT and MIT are plotted below the straight line, and synergistic effect can be obtained by using NaPT and MIT under alkaline conditions above pH 9 for Porphyrobacter sp. It was shown. Similarly, as shown in FIG. 2, the results of Tests 8 to 11 using NaPT and MIT for Pseudomonas pseudoalcaligenens were plotted below the straight line, indicating that synergistic effects could be obtained.

[Examples 1-16]

As an example, NaPT and MIT used in the above antimicrobial test were dissolved in water at different concentrations and blending ratios, and the pH was adjusted to about 9.4 using sodium hydroxide, and the aqueous alkaline antimicrobial solution was used. pH 9.4). Next, the coating liquid to which the aqueous liquid agent was added was airtight preserve | saved at 35 degreeC, and it sampled every fixed period, and cultured in PY agar medium (pH9), and measured the bacterial count in coating liquid.

[Comparative Examples 1-8]

NaPT or MIT was used alone as Comparative Examples 1 to 8, and others were tested in the same manner as in Example. Types and concentrations of the substances contained in the aqueous liquid formulations in Examples 3 to 16 in Table 3, pH of the aqueous liquid formulations, changes in the number of bacteria in the coating solution, and types of substances contained in the aqueous liquid formulations in Comparative Examples 1 to 8 in Table 4. And the concentration and pH of the aqueous liquid and the number of bacteria in the coating liquid are shown. In addition, in the following table, a "blank" shows the change of the number of bacteria in an untreated coating liquid, and the unit of the number of bacteria shows the number of cells / ml, and the column represented by "-" shows that the growth of the number of bacteria became remarkably impossible to measure.

[Examples 17-26]

As Examples 17 to 26, the alkaline aqueous liquid agent used in the above example was added to the calcium carbonate slurry (pH 10.7) instead of the circulating color coating solution of the above example, and the same test as in the above Example was performed.

[Comparative Examples 9-18]

The same test as in Examples 17 to 26 was conducted except that NaPT or MIT was used alone as Comparative Examples 9 to 18. In Table 5, Examples 17 to 26, and in Table 6 for Comparative Examples 9 to 18, the type and concentration of the substance contained in the aqueous liquid formulation, the pH of the aqueous liquid formulation, and the number of bacteria in the coating solution are shown.

As shown in Tables 3 to 6, in the examples to which the aqueous solution containing NaPT and MIT were added, the proliferation of microorganisms could be suppressed for a long time compared to the comparative example using NaPT or MIT alone. In particular, when added to the calcium carbonate slurry having a pH of more than 10 was shown to exhibit an antimicrobial effect over a long period of time at low concentrations compared to NaPT or MIT alone.

[Reference Examples 1-6]

In order to investigate the preservability of alkaline aqueous solution prepared by dissolving NaPT and MIT in water, NaPT and MIT were mixed as Reference Examples 1 to 6, or dissolved alone in water, and sodium hydroxide was added to pH 8.8 to 9.5. Adjusted. This was preserved at 40 ° C. for 2 months, and then liquid chromatography was used to measure the concentrations of NaPT and MIT in the aqueous solution. The results are shown in Table 7.

As shown in Table 7, in the alkaline aqueous liquid solution of Reference Example 2 in which MIT was dissolved in water alone, MIT was decomposed nearly 30%, but in Reference Examples 3 to 6 where NaPT coexisted, MIT was not substantially decomposed and maintained its initial concentration. .

According to the present invention, by using NaPT and MIT in alkaline conditions, a stable long-term antibacterial effect can be obtained. In addition, both NaPT and MIT are high safety materials, the industrial antimicrobial composition according to the present invention is less burden on the human body and the environment. Furthermore, since NaPT and MIT exert synergistic effects under alkaline conditions, high antibacterial activity can be obtained at low concentrations compared to the case of using NaPT or MIT alone. INDUSTRIAL APPLICATION This invention is applicable to the industrial antibacterial agent added to alkaline liquids, such as a papermaking coating liquid.

Claims (11)

An industrial antimicrobial composition comprising sodium pyrithione and 2-methyl-4-isothiazolin-3-one and added to an alkaline antibacterial target solution of pH 7 or higher. An industrial antimicrobial composition wherein sodium pyridion and 2-methyl-4-isothiazolin-3-one are dissolved in a solvent containing water to prepare an aqueous liquid formulation having a pH of 7 or more. The industrial antimicrobial composition of Claim 1 whose pH is 9-11. The industrial antimicrobial composition of Claim 2 whose pH is 9-11. The industrial antibacterial according to any one of claims 1 to 4, wherein the sodium pyrithione and the 2-methyl-4-isothiazolin-3-one are included in a weight ratio of 4: 1 to 1: 4. Composition. An antibacterial method of adding sodium pyridion and 2-methyl-4-isothiazolin-3-one to an alkaline antibacterial solution having a pH of 7 or higher. The sodium pyrithione and 2-methyl-4-isothiazolin-3-one are dissolved in a solvent containing water and added to the alkaline antibacterial target liquid as an aqueous solution having a pH of 7 or higher. Antibacterial method. The antimicrobial method according to claim 6, wherein the sodium pyrithione and the 2-methyl-4-isothiazolin-3-one are separately added to the alkaline antibacterial target liquid. The antimicrobial method according to any one of claims 6 to 8, wherein the alkaline antibacterial target liquid has a pH of 9-11. The said alkaline antibacterial object of any one of Claims 6-8 with which the said sodium pyrithione and the said 2-methyl-4-isothiazolin-3-one in a weight ratio of 4: 1-1: 4. Antibacterial method to add to the liquid. The antimicrobial method according to claim 10, wherein the sodium pyrithione and the 2-methyl-4-isothiazolin-3-one are added to the alkaline antibacterial target liquid in a ratio of 4: 1 to 1: 4 by weight.

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