JP2605764B2 - Slime control chemicals for petroleum fuels - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a slime control agent for controlling slime generated in petroleum fuel used for engines, generators, boilers and the like.

<Background of the problems> fungi, bacteria, yeasts, actinomycetes, etc., water, and the presence of nutrients, a suitable temperature, growth and industrial microbial contamination trying p ^H conditions abacus, corruption, degradation, discoloration, turbidity It causes precipitation, odor and the like. And since various troubles occur due to them, the controlling chemicals are used.

Fuels such as heavy fuel oil A, light oil, aviation fuel, and gasoline are stored in tanks, so that water is mixed in by tank breathing and condensation. In particular, microorganisms such as mold, bacteria, yeast, and actinomycetes are generated at the interface between the oil layer and the water layer, and a collection of these microorganisms and sludge in the system is called slime.
When the slime is generated, the slime adheres to or floats on tanks, pipes, and the like, causing clogging in an excessive process of the fuel, resulting in poor flow in the pipes. In general, heavy fuel oil A has troubles caused by asphaltenes and paraffin-based sludge. However, since these sediments are relatively slow and are dispersed, they are removed by passing through a centrifuge equipped with a centrifugal separator. On the other hand, slime mainly composed of microorganisms is large in shape and sticky, so that the filter is rapidly clogged, and the operation of the engine and the generator becomes impossible, which is dangerous for navigation of ships and the like. For this reason, slime control agents have been used in some ships in the past, but some molds, yeasts and the like have no slime control effect. For example, the following drugs have been used as conventional drugs. Methylenebisthiocyanate, benzalkonium chloride, 1,2-benzisothiazolin-3-one, nonionic and cationic surfactants and the like. These chemicals have been conventionally used for papermaking and as a slime control agent for cooling water, but they are (1) effective against bacteria but weak against mold, and (2) effective on culture media. Are difficult to dissolve in heavy fuel oil A, (3) the effect at the heavy fuel oil-water interface is weak, and (4) methylene bisthiocyanate is very toxic to living organisms.

<Means for Solving the Problems> The present inventors have conducted intensive research on the above problems, and as a result, the main component of the slime is filamentous fungi, and the water system at the oil layer interface
It p ^H is a weakly acidic, was further studied these fungi, that these filamentous fungus, Cladosporium sp., Penicillium sp., is a collection of various types of microorganisms consisting of Aspergillus, etc. and the candy data belonging to the genus of yeast And found that these fungi have a remarkable growth inhibitory effect at a low concentration (about 100 to 200 ppm) in the fuel and the water system at the interface, and easily dissolve in the fuel without deteriorating the fuel and are soluble in the water system at the interface. As a result of studying drugs that can be converted, the present invention has been completed.

That is, the present invention relates to 2-n-octyl-4-isothiazolone (compound A) and 2,3,5,6-tetrachloro-
An object of the present invention is to provide a slime control agent for petroleum-based fuels, which contains 4- (methylsulfonylpyridine (referred to as compound B) as an active ingredient and has a compounding ratio of 1: 0.1 to 5 parts by weight.

<Structure> Compounds A and B, which are the active ingredients of the present invention, are insoluble in water and soluble in an organic solvent, and may be used by adding a solvent, a surfactant and the like as necessary.

As the solvent, glycol solvents such as ethylene glycol, diethylene glycol, dipropylene glycol, alcohol solvents such as methanol, ethanol, oleyl alcohol, DMF, xylene, cyclohexanone, toluene, THF, and butyl cellosolve are used. As the surfactant, a nonionic or anionic surfactant is preferably used. As the nonionic surfactant, a polyoxyethylene type such as polyoxyethylene styrenated phenol, polyoxyethylene phenyl ether, or polyoxyethylene alkyl is used. Examples thereof include ethers and polyhydric alcohol esters such as sorbitan fatty acid esters. As anionic surfactants,
Alkyl aryl sulfonates are preferred, for example, sodium alkyl benzene sulfonate.

The mixing ratio of the compound A and the compound B is slightly different depending on the fuel, but is usually 0.1 to 5 parts, preferably 0.2 to 1 part, of the compound B to 1 part (parts by weight; the same applies hereinafter) of the compound A.

The content of the active ingredient in the pesticidal composition of the present invention varies depending on the dosage form and the purpose of use, but is generally about 1 to 30% by weight, preferably 10 to 30% by weight. At that time, the solvent is preferably 60 to 98% by weight, and the surfactant is preferably about 1 to 10% by weight.

Present controlling agent is p ^H adjusting buffering agent, antifreezing agents, perfumes,
An antifoaming agent, another industrial germicide, or the like may be added for use. Other industrial germicides include halogenated phenols, tetrachloroisophthalonitrile, diiodomethyl-p-tolylsulfone, 4-chlorophenyl-3-iodopropargyl formal, 3-iodo-2-propargyl butyl carbamate, N- Dimethyl-N-phenyl-
(N'-fluorodichloromethylthio) sulfamide,
2-bromo-2-nitro-1,3-propanediol, 1,2
-Benzisothiazolin-3-one, 2- (4-thiocyanomethylthio) benzothiazole, 2-methoxycarbonylaminobenzimidazole, 5-chloro-2-methyl-4-isothiazolin-3-one, 2-methyl-4
-Isothiazolin-3-one and the like, but are not limited to these examples.

Petroleum-based fuels include heavy oil, light oil, gasoline, kerosene, jet fuel and the like.

The amount of the control agent of the present invention added to petroleum-based fuels depends on the type of fuel, but is preferably 50 to 10,000 ppm, particularly 100 to 5 ppm.
000 ppm.

The agent of the present invention may be obtained by separately adding a compound A alone and a compound B alone to a fuel such as heavy oil A or adding compound A to a fuel and then adding compound B or compound B. After adding to the fuel, compound A may be added, or a mixture of compound A and compound B may be added to heavy oil A.

<Effect> The slime controlling agent of the present invention can be easily dissolved and mixed with various fuels, and has an excellent slime generation preventing effect at a low concentration. It does not cause a chemical reaction and does not have a strong effect on the human body (toxicity).

Hereinafter, the present invention will be described in detail with reference to Examples. Unless otherwise specified, “parts” and “%” are based on weight.

Example 1 and Comparative Examples 1-2 According to the above composition, compound B was dissolved in a mixed solvent (cyclohexanone, dimethylformamide) as in Example 1, and then compound A and penelol-N-100 (a nonionic surfactant manufactured by Matsumoto Yushi Pharmaceutical Co., Ltd.) were further added. It was added and dissolved to give a slime control agent.

In the same manner, the above-mentioned compounds prepared by using each of the compounds A and B alone in the mixed solvent were used as the slime control agents of Comparative Examples 1 and 2.

Test Example 1 (Antibacterial activity test) A drug solution diluted with sterilized water was prepared, and 1 ml of the diluted solution was added to 50
The mixture was mixed with 49 ml of a medium (potato decoction agar) at 9 ° C. and placed in a sterilized petri dish having a diameter of 9 cm to prepare an agar plate containing a drug solution having a predetermined concentration. Test bacteria (A) previously cultured on a slant medium at 28 ° C for 7 days
A spore suspension (isolated from heavy oil slime) was prepared, and a sterile 5 mm diameter paper disk was impregnated with each spore suspension and placed on a plate. These petri dishes were cultured at 28 ° C. for 7 days, and the presence or absence of growth of mold and yeast was examined, and the minimum drug concentration (minimum growth inhibitory concentration) for completely inhibiting the growth of each fungus was determined. The results were as shown in Table 1, and it was confirmed that the drug comprising the mixture of the compound A and the compound B of the present invention exhibited a synergistic antibacterial effect.

F-1 to Y-3 indicate the following molds and yeasts.

F-1: Cladosporium sp. F-2: Penicillium sp. F-3: Aspergillus sp. F-4: Fusarium sp. F-5: Penicillium sp. Y-1: Candida sp. Y-2: Candida sp. Y-3: Torulopsis sp. Drug slime in heavy oil A To confirm the control effect,
Experiments were conducted on the preventive effect of suppressing the germination of spores and the bactericidal effect of directly acting on already generated cells to kill fungi.

Test Example 2 (Spore suspension inoculation method) Test method 10 ml of an inorganic salt liquid medium was placed in a test tube of φ18 mm, and a predetermined amount of Example A and the control example were added with 9.5 m of heavy oil A.
l added. Next, bacterial spores were collected from the slant culture, dispersed in heavy oil A, and inoculated with 0.5 ml. 3 at 25 ℃ ± 2 ℃
After static culture for 0 days, it was examined whether slime was generated at the interface between the heavy oil A and the aqueous layer.

Judgment criteria-: No slime generated +: Low slime generation: High slime generation Active ingredient of commercial drug A: Organic nonmetal compound [Cleanside-S (Nippon Petroleum Product)] B: Cationic surfactant [Destall]・ F (Nippon Petrochemical) Test Example 3 (Microflora Inoculation Method) Test Method For inoculation, inoculate the microflora of each bacterium (mold: about 3 mm × 3 mm in size) and the yeast / platinum loop.

 Other conditions were the same as in the spore suspension inoculation method.

The agent of the present invention has an excellent slime generation control effect in heavy oil A even at a low concentration of about 100 to 250 ppm, a preventive effect by suppressing spore germination of each bacterium, and a bactericidal effect of killing already generated germs. I confirmed from the fact that there is.

Claims (1)

(57) [Claims] 1. An active ingredient comprising 2-n-octyl-4-isothiazolone and 2,3,5,6-tetrachloro-4- (methylsulfonyl) pyridine, and the mixing ratio thereof is 1: 0.1 to 5 parts by weight of a slime control agent for petroleum fuels.