JPH11140795A - Slime control agent and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high slime control effect under acidic and alkaline papermaking conditions without being affected by changes in operating conditions in the pulp and paper industry, and slime-constituting bacteria growing in process water, especially white water. Provided are a slime control agent and a slime control method effective for eradication and growth inhibition. SOLUTION: A slime control agent containing a specific hydantoin-based compound and a specific organic bromine-based compound in a ratio of 10: 1 to 1:10 (weight ratio), and the slime control agent in a paper / pulp industrial process water A slime control method in which the slime is added to and sterilized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slime control agent and a slime control method, and more particularly, to a slime control for effectively suppressing obstacles caused by slime generated in process water of various industries, particularly pulp mills and paper mills. The present invention relates to an agent and a slime control method.

[0002]

2. Description of the Related Art It is well known that in a pulp mill and a paper mill, the growth of microorganisms in the water used in the process causes various problems.
For example, white water in a paper machine of a paper mill contains a large amount of pulp that is a nutrient source of microorganisms, and various chemicals and fillers are added thereto. It is in a very favorable environment for propagation. When microorganisms propagate in white water, microorganisms and their metabolites aggregate to form sticky substances, so-called slimes.When these grow to a certain size, they are separated by the flow of process water and mixed into paper stock. , Causing stains, spots, eyeballs, etc. on the paper, which may impair the quality of the product, and cause other obstacles in the process such as paper breakage, clogging of wires or blankets, corrosion, odor, etc. Becomes Since the white water directly contacts the paper of the product and is partially incorporated into the paper, the slime generated there often causes more serious problems than those in general cooling water and process water.

[0003] There are two types of papermaking methods: so-called acidic papermaking, in which the pH is adjusted to 4 to 6, and alkaline papermaking, in which the pH is adjusted to 6 to 8. Recently, there is little corrosion of equipment in the process. Alkaline papermaking methods are increasing due to the fact that inexpensive calcium carbonate can be used as a filler and the quality of the produced paper is excellent. On the other hand, in the papermaking process, the recycling and reuse of white water has progressed, and it has come to be operated in a condition close to closed. As the recycling and reuse of white water in the alkaline papermaking process progresses, nutrients in the water are concentrated, and the water temperature rises. In addition, the optimal pH for the growth and growth of microorganisms is 6 to 8; The slime problem has become more serious as compared with the conventional acidic papermaking method, for example, because it is extremely convenient as a habitat for microorganisms. On the other hand, the ratio of waste paper reuse is increasing due to environmental issues such as protection of forest resources. Recycling of waste paper involves adding a large amount of various chemicals to improve the quality of the paper and to improve the yield in the process. Countermeasures have become increasingly important.

Various slime control agents have been proposed for preventing slime in process water of pulp mills and paper mills. For example, 2,2-dibromo-3-nitrillopropionamide, 2-bromo-4-
Hydroxyacetophenone, 1-bromoacetoxy-2
-Propanol, 1,4-bisbromoacetoxy-2-
Organic bromine-based compounds such as butene (Japanese Patent Publication No. 52
No. -12247, Japanese Patent Publication No. 52-46285,
JP-A-8-198715), 5-chloro-2-methyl-4-isothiazolone-3-one and 2-methyl-4
-Isothiazolone-3-ones represented by a mixture of -isothiazolone-3-ones (Japanese Patent Publication No. 25004/1986) and α-chlorobenzaldoxime (Japanese Patent Application Laid-Open No. 6-49).
797), a hydantoin-based compound (JP-A-8-1)
No. 76996) has been proposed.

[0005]

However, many of the slime control agents up to now are intended for acidic papermaking conditions with a pH of 4 to 6, which has been the mainstream in the past. These slime control effects are not always great. Furthermore, the use ratio of waste paper has increased, and slime disorders have been diversified, which has been unsatisfactory from the viewpoint of slime control. When a conventional slime control agent is applied to an alkaline papermaking system, the same effects as those of an acidic papermaking system are not achieved unless a large amount of chemicals are used, and the effect is not realized, and it is not practical in terms of processing cost. is there.

An object of the present invention is to provide a slime control agent and a slime control method which are not affected by changes in the operating conditions of the pulp and paper industry and exhibit high effects even under alkaline papermaking conditions.

[0007]

SUMMARY OF THE INVENTION The present inventors have considered the new problems such as the conditions in the alkaline papermaking method and an increase in the percentage of waste paper, and have shown that slime that can withstand such an environment and is effective. As a result of studying the control agent, it was found that the combined use of a specific hydantoin compound and a specific organic bromine compound exerted a synergistic effect to sufficiently achieve the object, and completed the present invention. .

That is, the invention of claim 1 is based on the general formula (I)

Embedded image (In the formula, R ¹ and R ² may be the same or different from each other, at least one is a chlorine atom or a bromine atom, and the other is any one of a chlorine atom, a bromine atom, and a hydrogen atom; ³ and R ⁴ may be the same or different and each represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms), and at least one hydantoin-based compound represented by the formula: At least one of organic bromine compounds having at least one selected from a cyano group, a nitro group, a carbonyl group, a carboxyl group, an amide group and a sulfone group as a substituent at the carbon atom at the α-position and / or the β-position. Seeds and 10: 1 to 1:10 (weight ratio)
Wherein the hydantoin-based compound is 1-bromo-3-chloro-5,5-dimethylhydantoin, 1,3-dichloro-5,5. One or more members selected from the group consisting of 5-dimethylhydantoin and 1,3-dibromo-5,5-dimethylhydantoin, and the organic bromine compound is 1,4-bis (bromoacetoxy) -2
-Butene, 1,2-bis (bromoacetoxy) -ethene, 1,2-bis (bromoacetoxy) propene, 2,
2-dibromo-3-nitrilopropionamide, 2,2
-Dibromo-2-nitroethanol and 2-bromo-
The slime control agent according to claim 1, which is at least one member selected from the group consisting of 2-nitro-1,3-propanediol, and the slime according to claim 1 or 2 according to claim 3 or claim 2. This is a slime control method in which a control agent is added to process water in a pulp mill or a paper mill to sterilize.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

In the hydantoin compound of the formula (I) according to the present invention, R ¹ and R ² may be the same or different from each other, at least one of which is a chlorine atom or a bromine atom, and the other is a chlorine atom. , A bromine atom or a hydrogen atom, and R ³ and R ⁴ may be the same or different from each other, and each represents a hydrogen atom or a carbon atom
Represents an alkyl group of 1 to 12. Examples of the alkyl group having 1 to 12 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an n-hexyl group,
2-ethylhexyl, n-octyl, n-dodecyl and the like. An alkyl group having 13 or more carbon atoms is not preferable because the water solubility of the hydantoin-based compound becomes poor. Specific examples of the hydantoin-based compound represented by the general formula (I) include 1-bromo-3-chloro-5,5-
Dimethylhydantoin, 1-bromo-3-chloro-5,
5-diethylhydantoin, 1-bromo-3-chloro-
Hydantoin, 1,3-dichloro-5,5-dimethylhydantoin, 1,3-dibromo-5,5-dimethylhydantoin and the like can be mentioned.

The organic bromine compound, which is the other component of the present invention, comprises a cyano group, a nitro group, a carbonyl group, a carboxyl group, an amide group at the carbon atom at the α-position and / or the β-position with respect to the bromine atom. And at least one organic bromine compound having at least one selected from a sulfone group and a sulfone group as a substituent. Specific examples thereof include 1,2-bis (bromoacetoxy) -ethene, 1,2-bis (bromoacetoxy) propene, 1,4-bis (bromoacetoxy) -2-butene, tribromonitromethane, 2,2 −
Dibromo-2-nitroethanol, 2-bromo-2-nitro-1-phenylethanol, 1,1-dibromo-1
-Nitro-2-propanol, 2-bromo-2-nitro-1-phenylpropanol, 2-bromo-2-nitrobutanol-2, 3-bromo-3-nitrobutanol-
2,2-bromo-2-nitro-1,3-butanediol, 2-bromo-2-nitro-1,3-butanediol, 2-bromo-2-nitro-1,3-propanediol, 2-bromo -2-nitro-1,3-pentanediol, 4,5-dibromo-1,2-dithiol, 5-bromo-5-nitro-1,3-dioxane, 1,2-dibromo-2,4-dicyanobutane , 2-bromo-3-nitrilopropionamide, 2,2-dibromo-3-nitrilopropionamide, N-methyl-2,2-dibromo-3
-Nitrilopropionamide, 2,2-dibromo-2-
Nitro-1-acetoxyethane, 2-bromo-2-nitro-1,3-diacetoxypropane, 1,2,3-tris (bromoacetoxy) propane, 1,3-diacetoxy-2-bromo-2-nitropropane Benzylbenzyl acetate, 1,1-dibromo-1-nitro-2-acetoxyethane, 1,1-dibromo-1-nitro-2-acetoxypropane, bis (tribromomethyl) sulfone, bromodicyanoacetamide, 1,4 -Dibromo-
2,3-butanedione, β-bromo-β-nitrostyrene, β-bromo-β-nitro-4-chlorostyrene, β
-Bromo-β-nitro-4-nitrostyrene, β-bromo-β-nitro-4-methylstyrene and the like.

The slime control agent of the present invention is a combination of a hydantoin compound of the formula (I) and an organic bromine compound. The hydantoin-based compound of the general formula (I) and the organic bromine-based compound shown above are effective as a slime control agent even when used alone. However, in order to obtain a synergistic effect by the combination of the present invention, the combination ratio must be reduced by weight. The ratio ranges from 10: 1 to 1:10, preferably from 5: 1 to 5: 1.

According to a fourth aspect of the present invention, the weight ratio of the hydantoin compound of the general formula (I) to the organic bromine compound is 10:
This is a slime control method in which a slime control agent containing 1 to 1:10 is added to process water in a pulp mill or a paper mill.

The process water in the pulp mill and paper mill of the present invention includes process water collectively referred to as so-called white water, such as a crushing wood process, a paper making process, a screen process, and a bleaching process, as well as the process water in a pulp mill and a paper mill. Includes all water handled in.

The amount of the slime control agent of the present invention added to the aqueous system depends on the water quality of the aqueous system, the type and number of living microorganisms, the degree of slime generation, the hydantoin compound of the general formula (I) and the organic bromine-based compound. Although it depends on the kind of the compound, the frequency of addition thereof, etc., it is not limited, but usually, the total amount of the hydantoin-based compound and the organic bromine-based compound of the general formula (I) is 0% with respect to the aqueous water. 0.1 to 100 ppm, preferably 0.5 to 50 pp
m, more preferably 1 to 20 ppm. 0.1p
pm, the effect is substantially small, and 100
If the content is more than ppm, the effect is sufficient, but the effect is not so great for the added amount, which is economically disadvantageous. At the above concentration that kills and inhibits the growth of slime-constituting bacteria, there is no effect on the process and the quality of the product is not impaired.

The hydantoin compound of the general formula (I) used in the present invention is solid at ordinary temperature and generally has a solubility of about 0.1 to 0.2% by weight in water. For the addition to the aqueous system, a method of adding the hydantoin-based compound to the aqueous system in the form of a powder or dissolving the compound in water or a hydrophilic organic solvent is used. Considering the easiness of addition to the process, a method of dissolving in water and injecting it into a necessary portion of the process using a pump or the like can be said to be preferable. Examples of the hydrophilic organic solvent include acetone, dioxane, dimethylformamide, γ-butyrolactone,
N-methylpyrrolidone, ethylene glycol, propylene glycol, diethylene glycol monomethyl ether, propylene carbonate, and the like. However, the inclusion of an iso-solvent in an aqueous system is not preferable because it can be a nutrient source of microorganisms, and should be minimized when used. When the compound is dissolved in water or a hydrophilic organic solvent, the compound is preferably added to the system as soon as possible after dissolution in consideration of the stability of the hydantoin compound.

When the other organic bromine compound used in the present invention is added to an aqueous system, it is added by dissolving it in a hydrophilic organic solvent. Examples of the hydrophilic organic solvent include acetone, dioxane, dimethylformamide, γ-butyrolactone, N-methylpyrrolidone, ethylene glycol, propylene glycol, diethylene glycol monomethyl ether, propylene carbonate, and the like.

For the addition to an aqueous system, the hydantoin-based compound of the general formula (I) and the organic bromine-based compound are separately or mixed and injected into a necessary portion in the process.

The addition to the aqueous system is carried out by a method of impact addition at a high concentration at a constant interval, a method of intermittent addition, or a method of continuous addition to always maintain a constant concentration, and is not particularly limited. The microorganisms may be added so that the number of surviving microorganisms is maintained at a level not more than -quantity and slime damage does not occur.

[0020]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples.

Example 1 100 mL of white water (pH = 7.5, viable cell count: 9 × 10 ⁸ cells / mL) from a neutral medium paper production machine in a paper mill was collected, placed in a 300 mL Erlenmeyer flask, and then slimeed. A predetermined amount of the control agent was added, and the mixture was brought into contact with a shaker for 30 minutes. This was followed by inoculation on a TGY agar medium [medium prepared by dissolving tryptone, yeast extract and glucose in pure water to adjust the pH to 7], and incubating at 32 ° C for 3 hours.
After culturing for one day, the number of viable bacteria per 1 mL of white water was measured.
The culture temperature of 32 ° C. used here is the temperature at which bacterial propagation is considered to be most active.

[0022] Similarly, the white water of the acidic quality paper manufacturing machine (pH = 5.5, the viable cell count: 8 × 10 ⁷ cells / mL) was collected and measured the number of viable bacteria in the same manner as described above.

The results are collectively shown in Table 1. From the results shown in Table 1, when the hydantoin compound and the organic bromine compound are used alone, the use of the hydantoin compound and the organic bromine compound has a large effect of killing and inhibiting the growth of microorganisms, and the combined use of the hydantoin compound and the organic bromine compound It can be seen that a synergistic effect is exhibited by the above, and the bactericidal effect is particularly remarkable even in a high pH range of 7.5.

[Hydantoin-based compound] HY-1: 1-bromo-3-chloro-5,5-dimethylhydantoin HY-2: 1,3-dichloro-5,5-dimethylhydantoin HY-3: 1,3- Dibromo-5,5-dimethylhydantoin [Organic bromine compound] BBAB: 1,4-bisbromoacetoxy-2-butene DBNPA: 2,2-dibromo-3-nitrilopropionamide DBNE: 2,2-dibromo-2- Nitroethanol BNPD: 2-bromo-2-nitro-1,3-propanediol

[0025]

[Table 1]

[0026]

The bactericidal effect is great when a hydantoin compound of the general formula (I) and an organic bromine compound are used in combination as a slime control agent.
High acid pH of 6 to 8 as well as the acidic side of 6
A sufficient effect is exhibited even in the H range. However, it is possible to kill or inhibit the growth of slime-constituting bacteria that grow in the process water of the pulp mill and the paper mill, and to prevent slime damage occurring in the process.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C02F 1/50 532 C02F 1/50 532D 532H 540 540C 540B // C07D 233/82 C07D 233/82

Claims (3)

[Claims] 1. A compound of the general formula (I) (In the formula, R ¹ and R ² may be the same or different from each other, at least one is a chlorine atom or a bromine atom, and the other is any one of a chlorine atom, a bromine atom, and a hydrogen atom; ³ and R ⁴ may be the same or different and each represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms), and at least one hydantoin-based compound represented by the formula: Organic bromine-based compound having, as a substituent, at least one selected from the group consisting of a cyano group, a nitro group, a carbonyl group, a carboxyl group, an amide group and a sulfone group at a carbon atom at the α-position and / or the β-position At least one of 10: 1 to 1:10
A slime control agent, which is contained at a ratio of (weight ratio). 2. The method according to claim 1, wherein the hydantoin compound is 1-bromo-3.
-Chloro-5,5-dimethylhydantoin, 1,3-dichloro-5,5-dimethylhydantoin and 1,3-
At least one member selected from the group consisting of dibromo-5,5-dimethylhydantoin, and the organic bromine compound is 1,4-bis (bromoacetoxy) -2-butene;
2-bis (bromoacetoxy) -ethene, 1,2-bis (bromoacetoxy) propene, 2,2-dibromo-3
-Nitrilopropionamide, 2,2-dibromo-2-
Nitroethanol and 2-bromo-2-nitro-1,
The slime control agent according to claim 1, which is at least one member selected from the group consisting of 3-propanediol. 3. A slime control method in which the slime control agent according to claim 1 or 2 is added to process water in a pulp mill or a paper mill and sterilized.