The quaternary ammonium salt is an active ingredient widely used in disinfection products, the most common being benzalkonium chloride, or chlorpheniramine. I often receive inquiries from users of this type of product. Which generation of quaternary ammonium salt are they using? Today I will tell you about the iterative history of quaternary ammonium fungicides.
Molecular structure of quaternary ammonium salt: quaternary ammonium salt, also known as quaternary ammonium salt. It is a salt of a quaternary ammonium cation formed by replacing all four hydogenions of an ammonium ion with a hydrocarbon group, and has the general formula R4N + X-. The four hydrocarbon groups may be the same or different. X- is mostly halogen anion, HSO4-, RCOO- and OH- (quaternary ammonium base).
Intergenerational division of quaternary ammonium salt: According to the development process of quaternary ammonium fungicide, it is often divided into at least seven generations of products:
1st generation: The first generation product is alkyl dimethyl benzyl ammonium chloride, which is also the simplest and most basic quaternary ammonium salt. It is often named after the number of carbon atoms on the substituent, such as 1227 (dodecyl dimethyl benzyl ammonium chloride, benzyl is 7 carbon atoms), 1631 (hexadecyl trimethyl ammonium chloride) .
2nd generation: The hydrgen on the benzene ring of the first generation product is replaced with chlorine, methyl and ethyl, such as: alkyl dimethyl ethyl benzyl ammonium chloride. The second-generation quaternary ammonium salts are basically not commercially used alone.
3rd generation: The third generation product is a mixture of the first and second generation quaternary ammonium salts. For example: an equal mixture of alkyl dimethyl benzalkonium chloride (1st generation) and alkyl dimethyl ethyl benzyl ammonium chloride (2nd generation). This combination of products not only improves the bactericidal effect, but also significantly reduces acute oral toxicity (mice oral LD50: 300mg / kg for the first generation product, 750mg / kg for the third generation product).
The third generation quaternary ammonium salt is rare in China, but it is a very classic disinfection ingredient in the United States. It often appears in the formulation tables of some old products, and it is indeed a milestone in business. Hundreds of disinfection products with the third-generation quaternary ammonium salt as the main ingredient can be found on the US EPA website. More well-known products include PDI's Sani-Cloth and Clorox's Scentiva Wipes.
4th generation: The fourth generation products are double long-chain quaternary ammonium salts. The product types include bis-octyl, bis-decyl, octyl-decyl and other combinations. Its bactericidal effect is obviously enhanced, and it is more resistant to hard water and organic interferences.
5th generation: The fifth generation product is a mixture of fourth and first generation quaternary ammonium salts. For example: a mixture of bisdecyl dimethyl ammonium chloride and alkyl dimethyl benzyl ammonium chloride. This combination is based on the principle of synergy of the third-generation quaternary ammonium salt formula. The commonly used component ratio is 60% and 40%. Its bactericidal effect and other properties are better than a single component.
6th generation: The sixth generation products are polymeric quaternary ammonium salts. Its main features are less toxicity and milder bactericidal effect (weaker than previous generations). Mainly reflects its medicinal value, such as polychloride in eye drops and contact lens care solution as a preservative.
Seventh generation: The seventh generation product is a mixture of the sixth generation and the first or third generation quaternary ammonium salt. The 7th generation quaternary ammonium salt commercial application cases are still few.
