JP3396721B2 - Industrial sterilization method - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to an industrial sterilization method. More specifically, it relates to an industrial sterilization method useful for sterilization of various industrial products, particularly industrial products exhibiting neutrality to alkalinity.

[0002]

2. Description of the Related Art Conventionally, many industrial products such as pulp slurries, coating colors, cutting oils, latices, synthetic resin emulsions, starch slurries, calcium carbonate slurries, muddy water polymers, fiber oils, lignins, etc. are caused by bacteria and fungi. It is known that spoilage and pollution occur, polluting products and reducing their value.

Many fungicides have been used to prevent damage by these microorganisms. Organic mercury compounds, chlorinated phenol compounds, formalin, etc. were used in old times, but these drugs are highly toxic to humans and seafood, and their use is regulated because they cause environmental pollution. Relatively low toxicity methylenebisthiocyanate, 1,2-benzisothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3
-One represented by organic nitrogen-sulfur system, 2,2-dibromo-2-nitroethanol, 2,2-dibromo-3-nitrilopropionamide, 1,2-bis (bromoacetoxy) ethane, 1,4-bis (Bromoacetoxy) -2-
Organic bromine compounds represented by butene and bistribromomethylsulfone and organic sulfur compounds represented by 4,5-dichloro-1,2-dithiol-3-one are widely used as industrial fungicides ( (See "Encyclopedia of Antibacterial and Antifungal Agents" published by the Japan Society for Antibacterial and Antifungal Agents in 1986)

However, many of these industrial bactericides are stable in the acidic range and decompose in the alkaline range, so long-term effects cannot be expected. That is, these industrial bactericides were added to the preservatives prepared in an alkaline range according to the needs of the market, for example, coating color, cutting oil, latex compound, calcium carbonate slurry, mud polymer, fiber oil agent, etc. at a normal concentration. However, since the bactericidal active ingredient decomposes over time, it was necessary to increase the amount of addition in anticipation of decomposition.

However, even in that case, the persistence of the bactericidal effect may be diminished or, in some cases, the decomposed product may lower the pH of the system to be sterilized and the product value may be impaired. In particular, in the case of coating colors and the like, if the pH is lowered, the viscosity increases, making continuous operation impossible.

[0006] Conventionally, in these alkaline preservative systems, compounds stable in the alkaline range, such as hexahydro-1,3,5-tris (2-hydroxyethyl)
-S-triazine, hexahydro-1,3,5-triethyl-S-triazine and other triazine compounds, 2-mercaptopyridine-N-oxide and other pyridine compounds, 1,2-benzisothiazolin-3-one, 2, -Industrial fungicides such as hydroxymethylaminoethanol were commonly used.

[0007]

Of these compounds that are stable in the alkaline range, the triazine-based compounds are alkaline themselves and therefore change the pH of the target system,
There is a drawback that it decomposes in the vicinity of neutrality, and since it has a weak bactericidal effect, it requires a large amount of addition, which is not economical.

The pyridine compound has a drawback that it is colored when a heavy metal such as iron or copper is present in the antiseptic system to contaminate the antiseptic system. Further, 1,2-benzisothiazolin-3-one has a weak bactericidal effect, so that a large amount needs to be added, which is not economical. An object of the present invention is to provide an industrial bactericide which sterilizes a system to be preserved in an alkaline region for a long period of time with a small amount of addition.

[0009]

In order to solve such problems, as a result of research on sterilization methods using various industrial bactericides having different combinations and content ratios, 2,2-dibromo-2-nitroethanol and 2-nitro-1,3-
Propanediol, when used alone, has no bactericidal action in the alkaline range and has a bactericidal effect only in the neutral to acidic range, but these were combined in a specific ratio. We have found the surprising fact that when used, it shows a strong bactericidal effect even in the alkaline range and that the bactericidal effect lasts.

This bactericidal sustaining effect is 2,2-dibromo-
By using 2-nitroethanol (A) and 2-bromo-2-nitro-1,3-propane-diol (B) in combination, the decomposition of each component over time in the alkaline range is suppressed. Was confirmed. Thus, according to the present invention, 2,2-dibromo-2-nitroethanol (A) and 2-bromo-2-nitro-1,3- are particularly suitable for sterilization target systems in the neutral to alkaline range of pH 7 to 9.5.
Propanediol (B) as the active ingredient, 95: 5 to 25:75
There is provided an industrial sterilization method, characterized in that the industrial sterilizer blended in a ratio of (weight ratio) is added simultaneously or separately so as to have an active ingredient concentration of 1 to 1000 mg / l .

The industrial sterilization method of the present invention comprises 2,2-dibromo-2-nitroethanol (A) and 2-bromo-
This is a method of sterilization using an industrial bactericide containing 2-nitro-1,3-propanediol (B) as an active ingredient and blended in a specific ratio. First, the industrial bactericide will be described in detail. It is known that the active ingredients (A) and (B) of the present invention each independently show antimicrobial activity (for example,
(A) and (B) are JP-B-40-8917).
When (A) and (B) are used in combination, the details of the reason why the remarkable effect is exerted in the alkaline range are not clear, but it is considered to be a synergistic action due to a specific combination of specific compounds.

In the industrial bactericidal agent of the present invention, the ratio of the active ingredients (A) and (B) that exerts a synergistic effect is that (A) to (B) is 95: 5 to 25:75 (weight ratio), preferably Is 95: 5-3
It is 5:65 (weight ratio). The industrial bactericide used in the present invention is preferably used by formulating it in the form of a normal liquid formulation, particularly an aqueous liquid formulation. However, the present invention is not limited to this, and may be used in the form of powder or the like depending on the object of use.

In the case of a one-pack formulation, water and / or a hydrophilic organic solvent may be used as a medium, and a dispersant may be optionally added to prepare a one-component formulation by a conventional method. As the hydrophilic organic solvent, amides such as dimethylformamide, glycols such as ethylene glycol, propylene glycol, diethylene glycol and dipropylene glycol,
Glycol ethers such as methyl cellosolve, phenyl cellosolve, diethylene glycol monomethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, alcohols having up to 8 carbon atoms or methyl acetate, ethyl acetate, 3-methoxybutyl acetate, 2-ethoxy. Esters such as methyl acetate, 2-ethoxyethyl acetate and propylene carbonate can be mentioned.

As the dispersant, a cationic surfactant,
Anionic surfactants, nonionic surfactants or amphoteric surfactants are suitable, and nonionic surfactants are preferred from the viewpoint of stability as a preparation. As the nonionic surfactant, higher alcohol ethylene oxide adduct (ethylene oxide is hereinafter abbreviated as EO), alkylphenol (EO) adduct, fatty acid (EO) adduct, polyhydric alcohol fatty acid ester (EO) adduct, Higher alkylamine (EO) adduct, fatty acid amide (EO) adduct,
Oil and fat (EO) adduct, propylene oxide [hereafter PO
Abbreviation] (EO) copolymer, alkylamine (PO) (E.
O) Copolymer adduct, fatty acid ester of glycerin, fatty acid ester of pentaerythritol, fatty acid ester of sorbitol and sorbitan, alkyl ether of polyhydric alcohol, alkylolamide and the like.

The blending ratio of the industrial bactericide used in the present invention is 3 to 50 parts by weight, preferably 10 to 30 parts by weight of the total amount of the active ingredient, and the dispersant is 1 part by weight of the total amount of the active ingredient. It is preferably at least 0.01 part by weight, and the balance is preferably a hydrophilic organic solvent. Furthermore, for the system to be sterilized in which the active ingredient of the present invention can be directly dissolved or dispersed, a direct or solid diluent (for example, kaolin, clay,
It may be used as a dust diluted with bentonite, CMC, etc.).

The amount of industrial fungicides used in the invention will vary by the object system, as 1 to 1000 mg / l, preferably the total amount of usually active ingredient is 5 to 200 mg / l. The industrial bactericide used in the present invention is preferably used as a one-pack formulation as described above, but each active ingredient may be separately added to the system to be sterilized. The method of the present invention has a strong bactericidal effect particularly in a neutral to alkaline range of pH 7 to 9.5, and is therefore used for a system to be sterilized in this range.

Examples of systems to be sterilized by these methods are industrial products, for example, 1) paper coating liquids (coating color, calcium carbonate slurry) used in paper / pulp factories, synthetic resin emulsions (latex, etc.), Starch pastes, pulp slurries, etc. and 2) metal working oils (cutting oils, rolling oils, etc.), fiber oils, emulsion paints, adhesives, sizing agents, latex compounds, cement dispersants and the like.

Industrial products which are particularly alkaline, such as coating colors, cutting oils, latex compounds,
Examples thereof include calcium carbonate slurry, muddy water polymer, fiber oil agent and the like. The liquid properties of these systems to be sterilized are as shown in Table 1, and those marked with a circle in the neutral to alkaline range are particularly suitable for the method of the present invention.

[0019]

[Table 1]

When the active ingredients are added simultaneously in the method of the present invention, it is convenient to use the same preparation as described above, but it is preferable to separate them from the viewpoint of long-term stability of the preparation. In cases where they are added separately, they are used as separate formulations. Also in this case, it is usually convenient to use liquid agents. Such a formulation can be prepared by a conventional method by adding the above-mentioned organic solvent and dispersant.

Further, the active ingredients of the present invention can be used directly or in the form of powders for the system to be sterilized in which they can be directly dissolved or dispersed. Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited thereto.

[0022]

EXAMPLES The active ingredients of the present invention will hereinafter be abbreviated by the following symbols. (A) DBNE: 2,2-dibromo-2-nitroethanol (B) BNPD: 2-bromo-2-nitro-1,3-
Propanediol

Test Example 1 DBNE (A), BNPD (B)
Synergistic effect test of L-shaped tubes sterilized in pH 9, 7, 5.9 buffer (phosphate buffer below pH 8 and carbonate-bicarbonate buffer above pH 9 with 0.01M concentration) And 10 ml each
We dispensed each. In this, the reagent agent (DBNE (A) and B
NPD (B) combination) was added to a predetermined concentration, and 0.1 ml of Pseudomonas aeruginosa IAM1514 preculture liquid was further added. Then, shaking contact was carried out at 37 ° C. for 60 minutes in a constant temperature bath. Then, the viable cell count was measured by the plate method. The results are shown in Table 2 and FIGS.

[0024]

[Table 2]

Comparative Test Example [Test of bactericidal activity of each drug alone at each pH] pH was adjusted to 4.5, 5 and 6 using MacIlvaine buffer, pH to 7 and 8 using phosphate buffer, or carbonic acid. After sterilizing the test solution whose pH was adjusted to 9 and 9.5 using a monocarbonate buffer, 10 ml was dispensed to each L-shaped tube. Each of these test solutions
Standard bacteria acclimated to the pH conditions (Pseudomonas aer u ginosa)
0.1 ml as a seed culture and 10 mg / l of a reagent were added. Then, the viable cell count (cells / ml) was measured after shaking contact at 37 ° C. for 60 minutes. The results are shown in Table 3.

[0026]

[Table 3]

Discussion of Test Examples and Comparative Test Examples: From the test examples, the active ingredients of the present invention, DBNE (A), BNPD
When combined with (B), a marked bactericidal effect is observed in alkaline regions where it is not effective alone. However, from the comparative test examples, when the active ingredient of the present invention is tested alone, it shows a remarkable bactericidal action only in the acidic region, but almost no bactericidal action in the alkaline region.

Test Example 3 Synergistic effect on coating color Coating color of a certain paper manufacturing company (A: pH 8.1, B: pH)
7.3, C: pH 7.8) are sampled respectively, and the drug is used at each concentration.
(Mg / l) , and leave it in a constant temperature bath at 30 ℃.
The bacterial count (cells / ml) was measured daily. All strains are Pseud
omonas sp. and Alcaligenes sp. Viable cell count (cells / ml) at the start of the test: Coating color A 3.9 × 10 ⁴ Coating color B 6.1 × 10 ⁵ Coating color C 3.6 × 10 ⁶ The results are shown in Tables 4, 5 and 6.

Description of symbols of drugs used in the following table MBTC: methylenebisthiocyanate BIT: 1,2-benzisothiazolin-3-one DBNPA: 2,2-dibromo-3-nitrosopropionamide Cl-MIT: 5-chloro 2-Methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-
3-one 9: 1 mixture DEG: diethylene glycol MDG: diethylene glycol monomethyl ether

[0030]

[Table 4]

[0031]

[Table 5]

[0032]

[Table 6]

[0033] to determine the concentration of the added day by day in each drug so that the drug to the concentration remaining rate S B R-series latex in Test Example 4 latex (pH 8.1) in HPLC (high performance liquid chromatography) The residual rate (%) was calculated. The results are shown in Table 7 and FIG.

[0034]

[Table 7]

Device of Test Example 4 ... Decomposition of each drug when each component alone or in combination was faster when alone.
When combined, the decomposition is suppressed and the bactericidal effect continues.

Formulation Example 1 Table 8 shows a formulation containing two components of DBNE (A) and BNPD (B) of the present invention as active ingredients. Unit is parts by weight
It

[0037]

[Table 8]

[0038]

The method of using a combination of DBNE (A) and BNPD (B) in a specific ratio shows a strong bactericidal effect in an alkaline range and sterilizes by suppressing decomposition of each component with time. It has a long-lasting effect and is useful for sterilizing alkaline industrial products, especially coating colors.

[Brief description of drawings]

FIG. 1 shows the synergistic effect of a combination of DBNE + BNPD at pH 9.

FIG. 2 shows the synergistic effect of the above combination at pH 7.

FIG. 3 shows the synergistic effect of the above combination at pH 5.9.

FIG. 4 is a diagram showing a daily survival rate of a combination of DBNE + BNPD and each alone.

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) A01N 33/20 101 A61L 9/01

Claims (2)

(57) [Claims] 1. A system to be sterilized, particularly in a neutral to alkaline range of pH 7 to 9.5, is provided with 2,2-dibromo-2-nitroethanol (A) and 2-bromo-2-nitro-1,3-propanediol ( B) as an active ingredient, and industrial bactericides mixed at a ratio of 95: 5 to 25:75 (weight ratio) are added simultaneously or separately so that the active ingredient concentration is 1 to 1000 mg / l. An industrial sterilization method characterized by: 2. The mixing ratio of (A) and (B) according to claim 1 is 95: 5 to 35:65 and the active ingredient concentration is 5 to 200 mg.
Industrial sterilization method which is / l .