JPH09124418A - Slime-controlling agent for cooling water system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject controlling agent containing a triazine compound in combination with 1-3 kinds of other compounds, effective for preventing the generation and proliferation of algae and the formation of slime of bacteria or mold by adding to cooling water and capable of effectively preventing the generation of slime. SOLUTION: This controlling agent contains (A) a triazine compound in combination with (B) at least one kind of compound selected from (a) a benzoisothiazolone compound or a bromonitroalcohol compound, (b) a polymer containing at least one kind of unsaturated carboxylic acid unit selected from acrylic acid unit, methacrylic acid unit, maleic acid unit and their salts and (c) a sulfonic acid or its salt. The triazine compound is preferably a compound of formula I (R<1> and R<3> are each H or a 1-4C alkyl; R<2> and R<4> are each a 1-4C alkyl) or formula II. The weight ratio of the components A and B is 1:9 to 9:1, preferably 3:7 to 7:3 or thereabout. The slime controlling agent is used by injecting into water at a rate to get a concentration of >=0.5mg/L, preferably 1-40mg/L.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a slime inhibitor for a cooling water system. More specifically, the present invention, by adding to cooling water, prevents the generation and reproduction of algae, the generation of mucilage of bacteria and fungi, and effectively prevents slime, a slime inhibitor for cooling water systems. Regarding

[0002]

2. Description of the Related Art In an open circulating cooling water system, water whose temperature has risen through a heat exchanger is recooled by passing through a cooling tower and is recycled. The open-circulation cooling water system is easily contaminated with dust, dust, and various organic substances mixed in from the atmosphere, and dirt (slime) mainly composed of microorganisms is easily generated. In particular, in a place exposed to light such as a watering tank of a cooling tower or a filling material, algae, which are microorganisms that have chlorophyll inside cells and carry out carbonic acid assimilation using light energy, propagate. The slime propagated in the sprinkling tank of the cooling tower and the filling material is gradually separated and suspended in the circulating water, transported to the heat exchanger and attached to the heat transfer surface, which not only causes a decrease in heat exchange efficiency, Local corrosion occurs at the bottom of the dirty heat transfer surface, significantly shortening the life of the metal material used for the heat exchanger, and when corrosion progresses significantly, it leads to penetration,
Gives a great deal of loss. When algae grow, bacteria and fungi also grow along with it, and the slime is formed by the inclusion of inorganic substances such as earth and sand due to the action of mucilage produced outside these bacteria. Conventionally, various slime control agents have been used to prevent these slimes, but even if they are effective against algae, they are not effective against bacteria and mold, and even if they are effective against bacteria and mold, they are not effective against algae. Therefore, it was often the case that a sufficient treatment effect could not be obtained.

[0003]

DISCLOSURE OF THE INVENTION The present invention is for a cooling water system which can be added to cooling water to prevent the generation and reproduction of algae and the formation of mucilage of bacteria and molds and effectively prevent slime. It was made for the purpose of providing an anti-slime agent.

[0004]

Means for Solving the Problems In order to solve the above problems, the present inventors have noticed that slime is composed of algae, bacteria, microorganisms such as mold and inorganic substances such as earth and sand. As a result of extensive research on triazine compounds that are effective in preventing outbreaks and materials that are used in combination with these to prevent bacteria and fungi from forming mucilage, a synergistic effect on slime prevention The combination that they have was found, and the present invention was completed based on this finding. That is, the present invention provides (1) a triazine compound (A) and (B) (a)
Benzisothiazolone compounds or bromonitroalcohol compounds, (b) polymers having at least one unsaturated carboxylic acid unit selected from acrylic acid units, methacrylic acid units, maleic acid units and salts thereof, and (c) phosphones 1 selected from acid or its salt
Or a slime inhibitor for a cooling water system containing two or more compounds, and (2) a triazine compound is a compound represented by the general formula [1] or the general formula [2]. A cooling water system slime inhibitor according to item (1),

Embedded image (However, in the formula, R ¹ and R ³ are hydrogen or a carbon number of 1 to 4
R ² and R ⁴ are alkyl groups having 1 to 4 carbon atoms. )

Embedded image (However, in the formula, R ¹ and R ³ are hydrogen or a carbon number of 1 to 4
R ² and R ⁴ are alkyl groups having 1 to 4 carbon atoms. ).

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The antislime agent of the present invention contains a triazine compound. The triazine compound used is not particularly limited as long as it has an effect of preventing the generation and reproduction of algae, and such a triazine compound is represented by the general formula [1] 6-methylthio-s-triazines. And 6-chloro-s represented by the general formula [2]
-Triazines and the like can be mentioned.

Embedded image However, in the general formula [1] and the general formula [2], R ¹
And R ³ are hydrogen or an alkyl group having 1 to 4 carbon atoms, and R ² and R ⁴ are alkyl groups having 1 to 4 carbon atoms.
Examples of the triazine compound represented by the general formula [1] include 2-ethylamino-4-isopropylamino-6.
-Methylthio-s-triazine, 2-methylamino-4
-Dimethylamino-6-methylthio-s-triazine,
2,4-bisdimethylamino-6-methylthio-s-triazine, 2-methylamino-4-isopropylamino-6-methylthio-s-triazine, 2-ethylamino-4-diethylamino-6-methylthio-s-triazine 2,4-bisisopropylamino-6-methylthio-s-triazine, 2,4-bisdiethylamino-6-
Methylthio-s-triazine etc. can be mentioned. Examples of the triazine compound represented by the general formula [2] include 2-ethylamino-4-tert-butyl-6-chloro-s-triazine and 2-ethylamino-
4-isopropylamino-6-chloro-s-triazine, 2,4-bisethylamino-6-chloro-s-triazine and the like can be mentioned. The slime inhibitor of the present invention is, in addition to the triazine compound which is the component (A),
As the component (B), at least one unsaturated carboxylic acid unit selected from (a) a benzoisothiazolone compound or a bromonitroalcohol compound, (b) an acrylic acid unit, a methacrylic acid unit, a maleic acid unit and salts thereof. And one or more compounds selected from (c) phosphonic acid or a salt thereof. The slime inhibitor of the present invention comprises a triazine compound as the component (A), a component (a) as the component (B),
The component (b) or the component (c) can be used in combination, and the component (a) and the component (b), the component (b) and the component (c), or the component (c) and the component (a) can be used. Two kinds of components can be used in combination, or three kinds of components (a), (b) and (c) can be used in combination.

Used in the slime preventive agent of the present invention (a)
The benzisothiazolone compound as a component is represented by the general formula [3]

[Chemical 6] (However, in the formula, R ⁵ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.) Or a benzisothiazolone or a lower alkyl-substituted product thereof. Examples of the compound represented by the general formula [3] include 1,2-
Benzisothiazolin-3-one, 1,2-benzisothiazolin-2-methyl-3-one, 1,2-benzisothiazolin-2-ethyl-3-one, 1,2-benzisothiazolin-2-isopropyl-3- On, 1, 2
-Benzisothiazolin-2-n-propyl-3-one, 1,2-benzisothiazolin-2-butyl-3-
On, 1,2-benzisothiazoline-2-pentyl-
3-on and the like can be mentioned. These compounds may be used alone or in combination of two or more. In order to use these benzisothiazolones and their lower alkyl-substituted compounds in a liquid state, it is preferable to adjust the pH of the antislime agent to 9 or more by using an alkali metal hydroxide, preferably potassium hydroxide.

Other (a) component bromonitroalcohol compounds used in the slime inhibitor of the present invention include:
General formula [4]

Embedded image (However, in the formula, R ⁶ and R ⁷ are alkylene groups having 1 to 5 carbon atoms, and they may be the same or different from each other.). Examples of the bromonitroalcohol compound represented by the general formula [4] include 2-bromo-2-nitropropane-1,
3-diol, 2-bromo-2-nitrobutane-1,4
-Diol, 2-bromo-2-nitropentane-1,5
-Diol, 3-bromo-3-nitropentane-1,5
-Diol, 2-bromo-2-nitrohexane-1,6
-Diol, 3-bromo-3-nitrohexane-1,6
-Diol, 2-bromo-2-nitroheptane-1,7
-Diol, 3-bromo-3-nitroheptane-1,7
-Diol, 4-bromo-4-nitroheptane-1,7
Mention may be made of diols and the like. These compounds may be used alone or in combination of two or more. Anti-slime agents containing bromonitro alcohol compounds have a pH of 5 for stabilization.
It is preferable to set the following. As the component (a) of the slime inhibitor of the present invention, only a benzoisothiazolone compound can be used, only a bromonitroalcohol compound can be used, or a combination of a benzoisothiazolone compound and a bromonitroalcohol compound can be used. You can

Used in the antislime agent of the present invention (b)
As the component, at least one selected from acrylic acid units, methacrylic acid units, maleic acid units and salts thereof.
Mention may be made of polymers having certain unsaturated carboxylic acid units. As such an unsaturated carboxylic acid-based polymer, a homopolymer composed of only one kind of unsaturated carboxylic acid unit can be used, and a copolymer having two or more kinds of unsaturated carboxylic acid units can be used. Further, a copolymer having one or more kinds of unsaturated carboxylic acid units and another monomer unit can be used. In the slime preventive agent of the present invention, the unsaturated carboxylic acid polymer as the component (b) can be used alone or in combination of two or more kinds. Examples of the raw material monomer that gives the unsaturated carboxylic acid polymer that is the component (b) of the present invention include acrylic acid, methacrylic acid, maleic acid, and salts of these unsaturated carboxylic acids, such as sodium salt and potassium salt. Examples thereof include alkali metal salts such as, and further, anhydrides of unsaturated carboxylic acids such as maleic anhydride. These monomers may be polymerized alone or 2
One or more kinds may be copolymerized, and one or more kinds of the monomers may be copolymerized with one or more kinds of other copolymerizable unsaturated compounds. Other copolymerizable unsaturated compounds include, for example, unsaturated alcohols, unsaturated carboxylic acid esters, alkenes, sulfone group-containing monomers and the like. Preferred examples of unsaturated alcohols include those having 4 or less carbon atoms such as allyl alcohol and methallyl alcohol. Preferable examples of unsaturated carboxylic acid esters include those having 6 or less carbon atoms such as methyl acrylate, ethyl acrylate, hydroxyethyl acrylate, and hydroxylethyl methacrylate. Preferable examples of the alkene include those having 8 or less carbon atoms such as isobutylene, n-butylene, diisobutylene and pentene. Examples of the sulfo group-containing monomer include vinyl sulfonic acid, 2-hydroxy-3-allyloxy-
Examples thereof include 1-propanesulfonic acid and styrenesulfonic acid. These unsaturated compounds may be used alone or in combination of two or more.

Used in the slime inhibitor of the present invention (c)
Examples of the phosphonic acid or its salt as the component include 1-hydroxyethylidene-1,1-represented by the formula [5].
Examples thereof include diphosphonic acid, phosphonic acid such as 2-phosphonobutane-1,2,4-tricarboxylic acid represented by the formula [6], and salts thereof.

Embedded image Examples of the phosphonic acid salt include alkali metal salts such as lithium salt, sodium salt and potassium salt, and alkaline earth metal salts such as magnesium salt and calcium salt. The phosphonic acid salt may be a normal salt in which hydrogen, which is a characteristic component of the acid, is completely replaced, or an acidic salt in which a part of hydrogen in the acid component remains. These phosphonic acids and salts thereof may be used alone or in combination of two or more. The blending ratio of the component (A) and the component (B) in the slime inhibitor of the present invention can be appropriately selected depending on the quality of water used, but usually the component (A): (B).
The weight ratio of the components is from 1: 9 to 9: 1, preferably from 3: 7.
It is selected in the range of 7: 3. In using the slime preventive agent of the present invention, if necessary, it may be diluted with a solvent in advance and then continuously diluted in water to a concentration of 0.5 mg / liter or more, preferably 1 to 40 mg / liter. It can be used by injecting it intermittently or intermittently.

[0010]

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Example 1 FIG. 1 is a perspective view of a test apparatus used in this example.
A model cooling tower 2 made of transparent acrylic resin is placed on the die light tank 1 having a volume of 30 liters, and at the bottom of the cooling tower,
A test board 3 made of lauan material having removable dimensions of 300 mm × 150 mm × 10 mm was attached. The test board is exposed to light. Put 20 liters of sewage treatment water shown in Table 1 into the dilite tank,
From a mixture of 2-ethylamino-4-isopropylamino-6-methylthio-s-triazine [(A) component] and 1,2-benzisothiazolin-3-one [(a) component] in a weight ratio of 1: 1. Containing 5mg of slime inhibitor
Add to make liter. Using the pump 4, water is guided at a rate of 1 liter per minute to the water spray plate 5 of the model cooling tower,
Water was dropped on the test board through the holes formed in the water spray plate, and the water dropped on the test board was returned to the die light tank through the pipe 6. To make it easier for microorganisms to reproduce,
The water temperature was maintained at 30 ° C.

[0011]

[Table 1]

In order to promote the growth of microorganisms, a mixture of glucose and yeast extract in a weight ratio of 1: 1 is used once a day B
An OD of 25 mg / liter was added, and deionized water was added at the same time to compensate for water loss due to evaporation, and the water amount was kept at 20 liters. The test board was removed after a test period of one month, all the slime adhering to the upper surface of the test board (surface area: 450 cm ² ) was collected, dried at 60 ° C. for 1 day, and weighed. Comparative Example 1 Example 1 was carried out in parallel with Example 1 except that the same sewage treatment water as the test apparatus having the same structure as that used in Example 1 was used and no slime inhibitor was added to the sewage treatment water. The exact same operation was performed. The dry weight of the slime attached to the test board after one month of the test period was 1,185 mg. The slime deposition amount of Example 1 of 30 mg corresponds to 2.5 wt% of the slime deposition amount of 1,185 mg of Comparative Example 1, and the slime prevention rate of Example 1 is determined to be 97.5%. Examples 2 to 4 Simultaneous with Example 1 except that the same sewage treatment water as the test apparatus having the same structure as that used in Example 1 was used and the slime inhibitor shown in Table 2 was added to the sewage treatment water. In parallel, the same operation as in Example 1 was performed. Table 2 shows the amount of slime deposited and the slime prevention rate. Comparative Example 2 Using the same sewage treatment water as in the test apparatus having the same structure as that used in Example 1, the sewage treatment water used as a slime inhibitor was 2-
Except that ethylamino-4-isopropylamino-6-methylthio-s-triazine [component (A)] was added so that the concentration was 5 mg / liter, in parallel with Example 1 and completely different from Example 1. The same operation was performed. The amount of slime adhered is 675 mg, and the slime prevention rate is 43.0%.
Met. Comparative Example 3 The same operation as in Comparative Example 2 was performed except that 2-ethylamino-4-tert-butylamino-6-chloro-s-triazine [component (A)] was used as a slime inhibitor. The amount of slime deposited was 563 mg, and the slime prevention rate was 52.5%. Comparative Example 4 1,2-benzisothiazoline-as a slime inhibitor
Except for using 3-one [(a) component], the same operation as in Comparative Example 2 was performed. The amount of slime deposited was 425 mg, and the slime prevention rate was 64.1%. Comparative Example 5 The same operation as in Comparative Example 2 was performed except that 2-bromo-2-nitropropane-1,3-diol [component (a)] was used as a slime inhibitor. The amount of slime adhered is 45
It was 0 mg, and the slime prevention rate was 62.0%.

[0013]

[Table 2]

[0014]

[Table 3]

In each of Examples 1 to 4 in which the slime preventive agent of the present invention comprising the component (A) and the component (a) was used, the slime preventive rate reached 97% or more, and an excellent slime preventive effect was obtained. In contrast, in Comparative Examples 2 to 3 using only the component (A) and Comparative Examples 4 to 5 using only the component (a), the same concentration of the drug as in Examples 1 to 4 was added. However, the slime prevention rate is low, and it can be seen from this result that the combined use of the component (A) and the component (a) produces a synergistic effect. Example 5 The same sewage treatment water as the test apparatus having the same structure as that used in Example 1 was used, and 2-
A slime inhibitor composed of a mixture of ethylamino-4-isopropylamino-6-methylthio-s-triazine [component (A)] and polymaleic acid [component (b)] in a weight ratio of 1: 1 had a concentration of 5 mg / liter. The same operation as in Example 1 was performed in parallel with Example 1 except that the addition was carried out. The amount of slime adhered is 150 mg,
The slime prevention rate was 87.3%. Examples 6 to 8 Simultaneous with Example 1 except that the same sewage treatment water such as a test apparatus having the same structure as that used in Example 1 was used and the slime inhibitor shown in Table 3 was added to the sewage treatment water. In parallel, the same operation as in Example 1 was performed. Table 3 shows the slime adhesion amount and the slime prevention rate. Comparative Examples 6 to 7 Other than using the same sewage treatment water as the test apparatus having the same structure as that used in Example 1 and adding a slime inhibitor consisting only of the component (b) shown in Table 3 to the sewage treatment water. In parallel with Example 1, the same operation as in Example 1 was performed. Table 3 shows the slime adhesion amount and the slime prevention rate.

[0016]

[Table 4]

In Examples 5 to 8 in which the slime preventive agent of the present invention comprising the component (A) and the component (b) was used, the slime preventive rate reached 87% or more, and an excellent slime preventive effect was obtained. In contrast, in Comparative Examples 6 to 7 in which only the component (b) was used, the slime prevention rate was low despite the addition of the same concentration of the chemical agent as in Examples 5 to 8. From this, it is understood that the combined use of the component (A) and the component (b) exhibits a synergistic effect. Example 9 The same sewage treatment water as the test apparatus having the same structure as that used in Example 1 was used, and 2-
It is composed of a mixture of ethylamino-4-isopropylamino-6-methylthio-s-triazine [component (A)] and 1-hydroxyethylidene-1,1-diphosphonic acid [component (c)] in a weight ratio of 1: 1. Anti-slime agent has a concentration of 5
Example 1 except that it was added so as to be mg / liter.
At the same time, the same operation as in Example 1 was performed in parallel.
The amount of slime adhered is 126 mg, and the slime prevention rate is 8
It was 9.4%. Examples 10 to 12 Simultaneous with Example 1 except that the same sewage treatment water as the test apparatus having the same structure as that used in Example 1 was used and the slime inhibitor shown in Table 4 was added to the sewage treatment water. In parallel, the same operation as in Example 1 was performed. Table 4 shows the slime adhesion amount and the slime prevention rate. Comparative Examples 8 to 9 Other than using the same sewage treatment water as the test apparatus having the same structure as that used in Example 1 and adding a slime inhibitor consisting only of the component (c) shown in Table 4 to the sewage treatment water. In parallel with Example 1, the same operation as in Example 1 was performed. Table 4 shows the slime adhesion amount and the slime prevention rate.

[0018]

[Table 5]

In Examples 9 to 12 using the slime preventive agent of the present invention comprising the components (A) and (c),
In all cases, the slime prevention rate reached 85% or more, and an excellent slime prevention effect was obtained, whereas in Comparative Examples 8 to 9 in which only the component (c) was used, the same concentration as in Examples 9 to 12 was obtained. The slime prevention rate is low in spite of the addition of the above chemicals, and it can be seen from this result that the synergistic effect is exhibited by the combined use of the component (A) and the component (c). Example 13 The same sewage treatment water as the test apparatus having the same structure as that used in Example 1 was used, and 2-
Of ethylamino-4-tert-butylamino-6-chloro-s-triazine [component (A)], 1,2-benzothiazolin-3-one [component (a)] and polymaleic acid [component (b)] Exactly the same operation as in Example 1 was carried out in parallel with Example 1 except that an antislime agent consisting of a mixture having a weight ratio of 1: 0.5: 0.5 was added to give a concentration of 5 mg / liter. went. The amount of slime adhered is 10
It was 4 mg, and the slime prevention rate was 91.2%. Example 14 Using the same sewage treated water as the test apparatus having the same structure as that used in Example 1, the sewage treated water was used as a slime preventive agent 2-
Ethylamino-4-tert-butylamino-6-chloro-s-triazine [(A) component], polymaleic acid [(b) component] and 1-hydroxyethylidene-1,1.
A weight ratio of diphosphonic acid [component (c)] of 1: 0.5: 0.
The same operation as in Example 1 was carried out in parallel with Example 1 except that the slime inhibitor consisting of the mixture of 5 was added so that the concentration was 5 mg / liter. The amount of slime adhered is 148 mg, and the slime prevention rate is 87.5%.
Met. Example 15 Using the same sewage treated water as the test apparatus having the same structure as that used in Example 1, the sewage treated water was used as a slime preventive agent 2-
Ethylamino-4-tert-butylamino-6-chloro-s-triazine [(A) component], 1,2-benzothiazolin-3-one [(a) component] and 1-hydroxyethylidene-1,1- Simultaneously with Example 1, except that a slime inhibitor consisting of a mixture of diphosphonic acid [component (c)] in a weight ratio of 1: 0.5: 0.5 was added to a concentration of 5 mg / liter. The same operation as in Example 1 was performed. The amount of adhered slime was 89 mg, and the slime prevention rate was 92.5%. Example 16 Using the same sewage treatment water as the test apparatus having the same structure as that used in Example 1, the sewage treatment water was treated with 2-
Ethylamino-4-tert-butylamino-6-chloro-s-triazine [(A) component], 1,2-benzothiazolin-3-one [(a) component], polymaleic acid [(b) component] and 1-hydroxyethylidene-1,1
A weight ratio of diphosphonic acid [component (c)] of 1: 0.4: 0.
A slime inhibitor consisting of a mixture of 3: 0.3 and a concentration of 5 m
Example 1 with the exception that it was added to g / l
At the same time, the same operation as in Example 1 was performed in parallel.
The amount of slime adhered is 134 mg, and the slime prevention rate is 8
It was 8.7%.

[0020]

[Table 6]

From the results of Examples 13 to 16, when the slime inhibitor prepared by blending the component (A) with two kinds of the components (a), (b) and (c) was used ( Even when a slime inhibitor prepared by blending all of the components (a), (b) and (c) into the component (A), the slime prevention rate reaches 88% or more, and the excellent slime prevention effect is obtained. Has been obtained. From these results, it can be seen that the synergistic effect is exhibited even when two or all of the components (a), (b) and (c) are used together with the component (A).

[0022]

EFFECT OF THE INVENTION By adding the slime inhibitor for a cooling water system of the present invention to cooling water, it is possible to prevent the generation and reproduction of algae and the production of mucilage of bacteria and molds and effectively prevent slime. it can.

[Brief description of the drawings]

FIG. 1 is a perspective view of a test apparatus used in Examples.

[Explanation of symbols]

 1 Dye Light Tank 2 Model Cooling Tower 3 Test Board 4 Pump 5 Sprinkler Plate 6 Pipe

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical indication location A01N 57:20) (72) Inventor Yasushi Murano 3-4-7 Nishishinjuku, Shinjuku-ku, Tokyo Kurita Industry Co., Ltd.

Claims (2)

[Claims] 1. A triazine compound (A), and (B)
(A) a benzoisothiazolone compound or a bromonitroalcohol compound, (b) a polymer having at least one unsaturated carboxylic acid unit selected from acrylic acid units, methacrylic acid units, maleic acid units and salts thereof, and ( c) A slime inhibitor for a cooling water system, which contains one or more compounds selected from phosphonic acid or a salt thereof. 2. The slime inhibitor for a cooling water system according to claim 1, wherein the triazine compound is a compound represented by the general formula [1] or the general formula [2]. Embedded image (However, in the formula, R ¹ and R ³ are hydrogen or a carbon number of 1 to 4
R ² and R ⁴ are alkyl groups having 1 to 4 carbon atoms. ) (However, in the formula, R ¹ and R ³ are hydrogen or a carbon number of 1 to 4
R ² and R ⁴ are alkyl groups having 1 to 4 carbon atoms. )