JPH08165204A - Algicide and method for preventing and exterminating algae i - Google Patents

Abstract

PURPOSE: To obtain an algicide capable of exhibiting excellent preventing and exterminating effects in the addition of a small amount by using sodium salt of 2-mercaptopyrimidine-N-oxide combined with N-substituted N- hydroxymethylamine or its polycondensation materials. CONSTITUTION: This algicide comprises containing (A) 2-mercaptopyrimidine- N-oxide or its alkali metal salts and (B) a N-substituted N-hydroxymethylamine of the formula I [R is a lower alkyl which may be substituted by OHj (n)=1--3] and its polycondensation materials [including the case of having a ring structure of formula II when (n)=3] in a weight ratio of (2:98)-(40:60), especially (4:96)-(16:84). This algicide can exhibit the preventing and exterminating effects on algae for a long period by using as small as possible amount, especially it can prevent and exterminate the algae of Hormidium genus and the above two components are preferably added by 0.5-100mg/ l.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an algae controlling agent and a method for controlling algae. More specifically, the present invention relates to an algae control agent and a method for controlling algae, which are extremely effective in preventing damages caused by algae breeding in various industrial water / drainage systems and various water storage systems.

[0002]

2. Description of the Related Art Various industrial water / drainage systems and various water storage systems, more specifically, cooling towers and water storage pits in cooling water systems, pools and open water storage tanks, and various types of irradiating sunlight such as rapid slips and fountains in play facilities. In the water system, green algae and cyanobacteria represented by genus Chlorelia and Anabaena breed and cause obstacles such as deterioration of water quality, generation of foul odors and impaired aesthetics, especially in cooling towers. It has been conventionally known that various problems such as deterioration of the temperature, induction of corrosion of metallic materials, and detached algae clog the strainer of the cooling system.

Therefore, various algae control agents have been proposed in the past, and in the past, organic mercury compounds such as mercury ethyl phosphate and phenyl mercury acetate, and chlorine compounds such as pentachlorophenol and trichlorophenol were used. . However, such drugs are not desirable because they are highly toxic, and their use is restricted from the viewpoint of preventing pollution.

With respect to this point, it has been proposed to use a compound having relatively low toxicity as an algae control agent, for example, glutaraldehyde, a quaternary ammonium salt, 3-
Cyclohexyl-6- (dimethylamino) -1-methyl-1,3,5-triazine and the like can be mentioned (JP-A-62-9).
6401, Japanese Examined Patent Publication No. 60-3361). In the 2-mercaptopyridine-N-oxide used in the present invention, its dimer or zinc salt is effective as an antibacterial / antibacterial agent (Merc
k Index page 1271), sodium salts, N-substituted N-hydroxymethylamines and polycondensates thereof are known as microbicides, and are used as industrial sterilizing / fungicides.

[0005]

However, when the above-mentioned low-toxicity agents are used, the algae control effect on site is often insufficient even when the practical concentration is used. Also, long-term effects could not be expected. As a result of the investigation by the inventors of the present invention, the target alga whose control effect is remarkably reduced is the subalgae (Ul.
otrichineae) was confirmed to be an alga containing the genus Hormidium. All of the algae of the genus Hormidium form unbranched filamentous filaments and propagate in a fibrous state so that they grow by entraining various scale components and slime-constituting bacteria, and have a form partially protected by these scales and the like. Therefore, it is presumed that the pesticidal effect is resistant to the control action of the drug and, as a result, the control effect is insufficient.

[0006] Although the above-mentioned various low-toxic drugs have low toxicity, it is desirable to reduce the use amount thereof as much as possible from the viewpoints of pollution prevention, environmental aspects and economical aspects. Therefore, an object of the present invention is to provide an algae control agent capable of exerting an algae control effect for a longer period of time with a use amount as small as possible, and particularly capable of controlling algae of the genus Holmium.

The inventors of the present invention have earnestly studied to achieve the above object, and as a result, 2-mercaptopyridine-N
-The combined use of sodium oxide and N-substituted N-hydroxymethylamine and its polycondensates exerts a remarkable synergistic effect. In fact, even with a small amount of addition, it is possible to treat green algae and cyanobacteria containing Hormidium. The present invention has been completed by finding the fact that the controlling effect is exerted and the effect lasts for a long time.

[0008]

Thus, according to the present invention, the active ingredient (a) 2-mercaptopyridine-N-
Oxide or an alkali metal salt thereof and (b) the general formula (I):

[0009]

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(In the formula, R is a lower alkyl group which may be substituted with a hydroxy group, n is an integer of 1 to 3) and N-substituted N-hydroxymethylamine and its polycondensate ( When n = 3, the formula:

[0011]

[Chemical 6]

At least one of the above (including the case of having a cyclic structure) is contained at a blending ratio of 2:98 to 40:60 by weight, and an algae control agent is provided. In the present invention, the alkali metal in the (a) component 2-mercaptopyridine-N-oxide or its alkali metal salt includes sodium, potassium and the like, of which the sodium salt is preferred. These are known compounds, and can be synthesized by a known method using 2-bromopyridine as a raw material, but as the sodium salt thereof, a commercially available product "Tomicide S" (trade name, manufactured by Yoshitomi Pharmaceutical Co., Ltd.) may be used.

In the present invention, the N-substituted N-hydroxymethylamine represented by the general formula (I) which is the component (b) and its polycondensate include 2- (hydroxymethylamino) ethanol, 2,4 -Bis (2-hydroxyethyl) diaza-1-butanol, 2,4,6-tris (2
-Hydroxyethyl) -2,4,6-triaza-1-hexanol, hexahydro-1,3,5-tris (2-
Hydroxyethyl) -s-triazine and hexahydro-1,3,5-triethyl-s-triazine. These compounds can be synthesized from monoethanolamine and paraformaldehyde (see British Patent No. 920301). In addition, commercially available products (manufactured by Yoshitomi Pharmaceutical Co., Ltd., trade name "Tomicide G", manufactured by Dainippon Ink and Chemicals Co., Ltd., trade names "Best Side 1087", "Best Side 1087T" or manufactured by RT Vanderbilt, trade name "Vancide" TH ") may be used.

In the agent for controlling algae of the present invention, the weight ratio of component (a) to component (b) is 2:98 to 40:60, preferably 4:96 to 32:68, more preferably 4 :.
By containing the compounding ratio of 96 to 16:84, a remarkable synergistic effect is exhibited. The synergistic effect of the present invention means that the algae killing rate is significantly improved and the algae to be controlled are of the genus Hormidium (Hormidiu) as compared with the case where they are used alone.
The effect of being extended to green algae and cyanobacteria including m).

The algae control agent of the present invention is usually prepared in the form of a liquid agent by directly mixing the respective active ingredients or by adding water or a hydrophilic solvent and, if necessary, a dispersant (surfactant). . Examples of the hydrophilic organic solvent include amides such as dimethylformamide, glycols such as ethylene glycol, propylene glycol, diethylene glycol and dipropylene glycol, methyl cellosolve, phenyl cellosolve, diethylene glycol monomethyl ether, dipropylene glycol monomethyl ether and tripropylene glycol. Glycol ethers such as monomethyl ether, alcohols having up to 8 carbon atoms or methyl acetate, ethyl acetate, 3-methoxybutyl acetate, 2-ethoxymethyl acetate, 2-
Esters such as ethoxyethyl acetate and propylene carbonate may be mentioned.

A mixed solvent of these hydrophilic organic solvent and water may be used. As the dispersant, a cationic surfactant, an anionic surfactant, a nonionic surfactant or an amphoteric surfactant is appropriate, and a nonionic surfactant is preferable in terms of stability as a preparation. Examples of the nonionic surfactant include higher alcohol ethylene oxide adducts (ethylene oxide is abbreviated as EO hereinafter), alkylphenol (EO) adducts, fatty acids (EO).
Adducts, polyhydric alcohol fatty acid ester (EO) adducts, higher alkylamine (EO) adducts, fatty acid amide (EO) adducts, oil and fat (EO) adducts, propylene oxide [ P. Abbreviated as O] (EO) copolymer,
Alkylamine (PO) (EO) copolymer adduct,
Examples thereof include glycerin fatty acid ester, pentaerythritol fatty acid ester, sorbitol and sorbitan fatty acid ester, sucrose fatty acid ester, polyhydric alcohol alkyl ether, and alkylolamide.

The proportion of the algae control agent of the present invention is preferably 1 to 85 parts by weight of the total amount of the active ingredients, and the balance is water or a hydrophilic organic solvent. Also, if necessary, the dispersant is at least 0.01 per 1 part by weight of the total of the active ingredients.
Part by weight may be blended. The algae control agent of the present invention further contains 5-chloro-2-methyl-isothiazoline-3.
3-isothiazolones such as -one, 4,5-dichloro-2-octyl-isothiazolin-3-one, 2-bromo-2-nitropropane-1,3-diol, 2-bromo-2-nitro-1, Bromonitroalcohol derivatives such as 3-diacetoxypropane, quaternary ammonium compounds such as benzalkonium chloride, urea derivatives such as 3- (3,4-dichlorophenyl) -1,1-dimethylurea, methylenebisthiocyanate, glutar Known algae control agents such as aldehydes, bactericides, defoamers and scale dispersant components may be added.

The respective active ingredients of the algae controlling agent of the present invention may be added to the system for controlling algae simultaneously or separately as separate preparations depending on the case. Therefore, from this viewpoint, (a) 2-mercaptopyridine-N-oxide sodium salt and (b) N-substituted N-hydroxymethylamine and at least one polycondensate thereof are simultaneously or separately added to the system for controlling algae. There is provided a method for controlling algae, which comprises adding a trace amount to algae.

In this case, the combination ratio is 2: 9 as the weight ratio of the component (a) and the component (b) as in the case of the algae control agent of the present invention.
The ratio of 8 to 40:60, preferably 4:96 to 32:68, and more preferably 4:96 to 16:84 produces a remarkable synergistic effect. Examples of the system for controlling algae of the present invention include a cooling tower and a water storage pit in a cooling water system, various industrial water / drainage systems and various water storage systems exposed to sunlight such as rapid slides and fountains in pools and open water tanks and amusement facilities. .

In the present invention, the active ingredients ((a) component and (b)
The total amount of the components) is 0.5 to 100 mg / L, preferably 1 to 60 mg / L, and more preferably 10 to 50 mg / L with respect to the algae control target water. Addition amount is 0.
If it is less than 5 mg / L, an effective algae control effect cannot be exhibited, which is not preferable, and more than 100 mg / L may be added, but it is not preferable for economic reasons.

[0021]

EXAMPLES The present invention is illustrated by the following examples and test examples. Example (Formulation Example) The following formulation was prepared as an example of the present invention. Formulation Example 1 HMAE 50 parts by weight MPO-Na 5 parts by weight Tap water 45 parts by weight Formulation Example 2 HMAE 60 parts by weight MPO-Na 3 parts by weight Tap water 37 parts by weight Formulation Example 3 HMAE 80 parts by weight MPO-Na 4 parts by weight Water supply Water 16 parts by weight Formulation Example 4 HETA 50 parts by weight MPO-Na 5 parts by weight Tap water 45 parts by weight Formulation Example 5 HETA 60 parts by weight MPO-Na 3 parts by weight Tap water 37 parts by weight Formulation Example 6 HETA 80 parts by weight MPO-Na 4 parts by weight Tap water 16 parts by weight The relationship between the abbreviations in the formulation examples and the active ingredients is shown below. The same applies to the following test examples. MPO-Na: 2-Mercaptopyridine-N-oxide sodium salt HMAE: 2- (Hydroxymethylamino) ethanol HETA: Hexahydro-1,3,5-tris (2-
Hydroxyethyl) -s-triazine Test Example 1 [Test for confirming synergistic effect on algae control] 10 ml of cooling water containing algae (Chlorella, Westella, Quadrigula mainly mixed) collected from a cooling tower (cooling tower) of a petrochemical company Each of them was dispensed into an L-shaped test tube, a predetermined amount of each active ingredient was added, and the initial absorbance (420 nm) was measured with a photoelectric colorimeter. Thereafter, a light amount of 1500 lux was applied at a constant temperature (25 ° C.) and shaken continuously for 3 days, and after 3 days, the algal killing rate was calculated by the following formula based on the increase / decrease in absorbance.

[0022] B _X : Absorbance on day 3 without addition of active ingredient B _O : Initial absorbance without addition of active ingredient A _X : Absorbance on day 3 after addition of active ingredient A _O : Initial absorbance on addition of active ingredient Among the test results of the algae control synergistic effect confirmation test by the above, the result of the synergistic effect confirmation test between MPO-Na and HMAE is shown in FIG. 1, and the result of the synergistic effect confirmation test between MPO-Na and HETA is shown in FIG. 2, respectively.

As is apparent from FIGS. 1 and 2, the component (a) and the component (b) of the present invention have a weight ratio of 2: 98-4.
It can be seen that a remarkable synergistic effect is exhibited by the combined use at a ratio of 0:60, preferably 4:96 to 32:68, and more preferably 4:96 to 16:84. Also,
FIG. 3 shows the relationship between the added amount of the algae controlling agent composed of MPO-Na and HMAE and the algal killing rate, and FIG. 4 shows the relationship between the added amount of the algal controlling agent consisting of MPO-Na and HETA and the algicidal rate. Are shown respectively. Test Example 2 [Algae control synergistic effect confirmation test] Algae (Hormidium) collected from a rapid slip at a certain amusement facility
Was conducted as a test water, and a test for confirming algae control synergistic effect of each active ingredient was conducted in the same manner as in Test Example 1.

Among the test results of the algal control synergistic effect confirmation test based on the mixing ratio of each active ingredient, the synergistic effect confirmation test result of MPO-Na and HMAE is shown in FIG. 5, and MPO-Na and HET.
The results of the synergistic effect confirmation test with A are shown in FIG. As is clear from FIGS. 5 and 6, (a) component of the present invention
The weight ratio of the component (b) to the component is 2:98 to 40:60, preferably 4:96 to 32:68, and more preferably 4: 9.
It can be seen that a conspicuous synergistic effect is exhibited by the combined use in the ratio of 6 to 16:84.

[0025]

EFFECTS OF THE INVENTION According to the present invention, various obstacles due to the reproduction of algae, particularly green algae containing genus Hormidium and cyanobacteria can be eliminated by using a very low concentration drug. In addition, the algae control agent of the present invention shows almost no toxicity, corrosiveness, skin irritation, effervescence and the like.

Therefore, the algae control agent of the present invention has extremely high industrial utility.

[Brief description of drawings]

FIG. 1 MPO-Na and HMA for algae in the cooling tower
It is a graph which shows the result of the synergistic effect confirmation test of E.

FIG. 2 MPO-Na and HET for algae in the cooling tower
It is a graph which shows the result of the synergistic effect confirmation test of A.

FIG. 3 is an algal control agent (MPO-) for algae in the cooling tower.
It is a graph which shows the relationship between the addition amount of Na: HMAE = 8: 92) and the algal killing rate.

FIG. 4 is an algal control agent (MPO-) for algae in the cooling tower.
It is a graph which shows the relationship between the addition amount of Na: HETA = 8: 92) and the algal killing rate.

[Figure 5] MPO for algae in a rapid stream of a play facility
It is a graph which shows the synergistic effect confirmation test result of -Na and HMAE.

[Figure 6] MPO for algae in a rapid stream of a play facility
It is a graph which shows the synergistic effect confirmation test result of -Na and HMAE.

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[Procedure amendment]

[Submission date] February 20, 1995

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be amended] Title of invention

[Correction method] Change

[Correction content]

Title: Algae control agent and algae control method I

Claims (8)

[Claims] 1. As an active ingredient, (a) 2-mercaptopyridine-N-oxide or an alkali metal salt thereof and (b) a general formula (I): (In the formula, R is a lower alkyl group which may be substituted with a hydroxy group, and n is an integer of 1 to 3).
Substituted N-hydroxymethylamine and its polycondensate (n
= 3, the formula: (Including the case of having a cyclic structure of 1.) in an amount of 2:98 to 40:60 as a weight ratio. 2. The algae control agent according to claim 1, wherein the alkali metal salt of the component (a) is a sodium salt. 3. The algae control agent according to claim 1, wherein the weight ratio of the component (a) and the component (b) is 4:96 to 32:68. 4. The algae control agent according to claim 1, wherein the weight ratio of the component (a) to the component (b) is 4:96 to 16:84. 5. A system for controlling algae, wherein (a) 2-mercaptopyridine-N-oxide or an alkali metal salt thereof and (b) general formula (I): (In the formula, R is a lower alkyl group which may be substituted with a hydroxy group, and n is an integer of 1 to 3).
Substituted N-hydroxymethylamine and its polycondensate (n
= 3, the formula: (Including the case of having a cyclic structure of 1.) at the same time or separately. 6. The method for adding a component (a) and a component (b) in a weight ratio of 2:98 to 40:60 in an amount of 0.5 mg / L to 100 mg / L to the system for controlling algae. 4. The method for controlling algae according to 4. 7. A component (a) added to a system for controlling algae
The ratio with the component (b) as a weight ratio is 4:96 to 32:68.
The method for controlling algae according to claim 4. 8. A component (a) added to a system for controlling algae
The weight ratio of the component (b) to the component is 4:96 to 16:84.
The method for controlling algae according to claim 4.