Verfahren zur Herstellung eines 3-Isothiazolongemisches und eine das Gemisch enthaltende Zusammensetzung

• Main Authors: KIM, JIN-MAN, SUWON, KYONGGI, KR, HAHN, SOON-JONG, SEOUL/SOUL, KR, LIM, JIN-SOO, KWACHEON, KYONGGI, KR, KIM, SEUNG-HWAN, SUWON, KYONGGI, KR
• Format: Patent
• Language: German
• Published: 26.06.1997
• Edition: 6
• Subjects: AGRICULTURE; ANIMAL HUSBANDRY; BIOCIDES, e.g. AS DISINFECTANTS, AS PESTICIDES, AS HERBICIDES; CHEMISTRY; FISHING; FOODS OR FOODSTUFFS; FOODS, FOODSTUFFS, OR NON-ALCOHOLIC BEVERAGES, NOT COVERED BYSUBCLASSES A23B - A23J; FORESTRY; HETEROCYCLIC COMPOUNDS; HUMAN NECESSITIES; HUNTING; HYGIENE; MEDICAL OR VETERINARY SCIENCE; METALLURGY; ORGANIC CHEMISTRY; PEST REPELLANTS OR ATTRACTANTS; PLANT GROWTH REGULATORS; PREPARATIONS FOR MEDICAL, DENTAL, OR TOILET PURPOSES; PRESERVATION OF BODIES OF HUMANS OR ANIMALS OR PLANTS OR PARTSTHEREOF; PRESERVATION OF FOODS OR FOODSTUFFS, IN GENERAL; SPECIFIC USE OF COSMETICS OR SIMILAR TOILETPREPARATIONS; THEIR PREPARATION OR TREATMENT, e.g. COOKING, MODIFICATION OFNUTRITIVE QUALITIES, PHYSICAL TREATMENT; THEIR TREATMENT, NOT COVERED BY OTHER CLASSES; TRAPPING

An impurity-free biologically active mixture of 2-methyl-4-isothiazolin-3-one (I) and 5-chloro-2-methyl-4-isothiazolin-3-one (II), which is useful as a biocide (eg against fungi, bacteria and algae) in various products, can be prepared by reacting N-methyl-3-mercaptopropionamide (A-1) or N,N'-dimethyl-3,3'-dithiodipropionamide (A-2) or a mixture thereof with a chlorinating agent at a temperature ranging from 5 to 20 {C and, optionally, centrifuging the resulting product mixture to obtain the desired mixture. By this process, a mixture of (I) and (II) can be obtained in which the concentration of (II) is sufficiently high so as to yield a biologically active mixture and yet in which the concentration of an undesired impurity 2-methyl-4-isothiazolin-3-one (III) is kept below 100 ppm based on 15000 ppm of (I) and (II). A stabilized isothiazolone composition is also disclosed which comprises: (A) a biologically effective amount of a mixture of (I) and (II); (B) an effective amount of a metal nitrate stabilizer; and (C) a sufficient amount of water to dissolve the components (A) and (B), the composition containing less than 100 ppm of (III) based on 15,000 ppm of the component (A):