Background

Isothiazolinone is a fungicide with the chemical formula C₈H₉ClN2O₂S₂, mainly composed of 5-chloro-2-methyl-4-isothiazolin-3-one (CIT) and 2-methyl-4-isothiazoline-3 - Ketone (MIT) composition. Isothiazolinones act by breaking bonds in bacterial and algal proteins. After contacting with microorganisms, isothiazolinones can rapidly and irreversibly inhibit their growth, resulting in the death of microbial cells, so they have strong inhibitory and killing effects on common bacteria, fungi, and algae. Isothiazolinone fungicides are also widely used in iron and steel smelting, oil field water injection, oil refineries, thermal power plants, large fertilizer plants, paper mills, textiles, water coatings, industrial cleaning and other fields[1].

Picture 1 Isothiazolinone liquid

Isothiazolinone fungicides

Isothiazolinone bactericide is a heterocyclic structure, and its bactericidal principle mainly relies on the active part on the heterocyclic ring to destroy the DNA molecule in the bacterial cell, making the bacteria inactive. Isothiazolinone fungicides were first formed by Americans by halogenation of β-thione amides in inert organic solvents, and are considered to be the best fungicides in water treatment applications due to their high efficiency, broad spectrum and low toxicity. . In addition, isothiazolinone fungicides are also widely used in iron and steel smelting, oil field water injection, oil refineries, thermal power plants, large fertilizer plants, paper mills, textiles, water coatings, industrial cleaning and other fields. Common isothiazolinone fungicides are: 1,2-benzisothiazolin-3-one (BIT), 2-n-octyl-4-isothiazolin-3-one (OIT), 2- Methyl-4-isothiazolin-3-one (MIT), 5-chloro-2-methyl-4-isothiazolin-3-one (CMIT). Their common features are the advantages of strong antibacterial ability, small application dose, good compatibility and low toxicity, and it has a strong antibacterial effect on a variety of bacteria and fungi. They have their high efficiency, good compatibility, wide pH range, and natural biodegradation.

Performance and use

The isothiazolinones are mainly composed of 5-chloro-2-methyl-4-isothiazolin-3-one (CIT) and 2-methyl-4-isothiazolin-3-one (MIT). Isothiazolinones act by breaking bonds in bacterial and algal proteins. After contacting with microorganisms, isothiazolinones can rapidly and irreversibly inhibit their growth, resulting in the death of microbial cells, so they have strong inhibitory and killing effects on common bacteria, fungi, and algae. It has the characteristics of high killing efficiency, good degradability, no residue, safe operation, good compatibility, strong stability and low cost of use. It is miscible with chlorine and most anionic, cationic and nonionic surfactants. At high doses, isothiazolinones have a significant effect on bioslime exfoliation. Isothiazolinone is a broad-spectrum, high-efficiency, low-toxicity, non-oxidizing biocide. Widely used in oil field, papermaking, pesticide, cutting oil, leather, ink, dye, leather and other industries.

Development and prospect

Isothiazolinone antibacterial preservatives were first developed by Rohm and Haas Company in 1972, and after 2015, Dalian Bio Chemical Co., Ltd. was first introduced into China and popularized and applied. The foreign trade name is KATHON WT, which is an internationally recognized safe, efficient and broad-spectrum new fungicide. It has been gradually used in iron and steel smelting, oil field, power generation, light textile, oil refining, chemical industry, industrial cleaning, cutting oil, wood, cooling circulating water and other industrial fields for sterilization, mildew prevention, anticorrosion and algae killing. The advantages of isothiazolinone fungicides have been widely accepted by enterprises. The application scope and dosage in the field of disinfection are expanding and rising year by year. Very optimistic and considered to be the best fungicide currently on the market.

Reference

1 Qu Zhenbin.Exploration on the application of isothiazolinone fungicides[J].Chemical Design Communications,2016,42(09):103.