Stabilization of non-aqueous solutions of 3-isothiazolones

Abstract

Non-aqueous solutions of 3-isothiazolones are stabilized against chemical decomposition by using organic hydroxylic solvents. These compositions exhibit bactericidal, fungicidal and algaecidal properties.

I claim: .[.1. A method for stabilizing a 0.5 to about 10% by weight solution of an isothiazolone of the formula: ##STR3## wherein Y is an unsubstituted alkyl of 1 to 8 carbon atoms, an unsubstituted or halo substituted alkenyl or alkynyl of 2 to 8 carbon atoms, an unsubstituted cycloalkyl of 5 to 8 carbon atoms, benzyl, aralkyl selected from 3,4-dichlorobenzyl, 4-methoxybenzyl or 4-chlorobenzyl or substituted aryl selected from 3,4-dichlorophenyl or 4-methoxyphenyl; R is halo; R 1   is hydrogen, halogen or (C 1  -C 4 )alkyl which consists of formulating a solution of the isothiazolone by dissolving the isothiazolone in from about 90 to about 99% by weight of dipropylene 
     
        glycol, polypropylene glycol, 1,5-pentadiol or benzyl alcohol..]. .[.2. The method of claim 1 wherein the isothiazolone is 5-chloro-2-methyl-4-isothiazolin-3-one..]. .[.3. The method of claim 1 wherein the solvent is dipropylene glycol..]. .[.4. A stabilized solution consisting essentially of from 0.5 to 10% by weight of a compound of the formula: ##STR4## wherein Y is an unsubstituted alkyl of 1 to 8 carbon atoms, an unsubstituted or halo substituted alkenyl or alkynyl group of 2 to 8 carbon atoms, an unsubstituted cycloalkyl of 5 to 8 carbon atoms, benzyl, or 3,4-dichloro phenyl or 4-methoxy phenyl R is halo; R 1  is hydrogen, halogen or (C 1  -C 4 ) alkyl, and from 90 to 99.5% by weight of dipropylene glycol, polypropylene glycol,   
     
     
        1,5-pentanediol or benzyl alcohol..]. .[.5.  The solution of claim 4 wherein the isothiazolone is 5-chloro-2-methyl-4-isothiazolin-3-one..]. .[.6. The solution of claim 4 wherein the solvent is dipropylene 
     
     
        glycol..]. .Iadd.7.  A method for stabilizing a 0.5 to about 10% by weight solution of an isothiazolone of the formula: ##STR5## wherein Y is an unsubstituted alkyl of 1 to 8 carbon atoms, an unsubstituted or halo substituted alkenyl or alkynyl of 2 to 8 carbon atoms, an unsubstituted cycloalkyl of 5 to 8 carbon atoms, benzyl, aralkyl selected from 3,4-dichlorobenzyl, 4-methoxybenzyl or 4-chlorobenzyl or substituted aryl selected from 3,4-dichlorophenyl or 4-methoxyphenyl; R 1  is halo; R is hydrogen, halogen or (C 1  -C 4 ) alkyl which consists of formulating a solution of the isothiazolone by dissolving the isothiazolone in from about 90 to about 99% by weight of dipropylene glycol, polypropylene glycol, 1,5-pentadiol or benzyl alcohol. .Iaddend. 
     
     
        .Iadd.8.  The method of claim 7 wherein the isothiazolone is 5-chloro-2-methyl-4-isothiazolin-3-one. .Iaddend. .Iadd.9. The method of claim 7 wherein the solvent is dipropylene glycol. .Iaddend. .Iadd.10. A stabilized solution consisting essentially of from 0.5 to 10% by weight of a compound of the formula: ##STR6## wherein Y is an unsubstituted alkyl of 1 to 8 carbon atoms, an unsubstituted or halo substituted alkenyl or alkynyl group of 2 to 8 carbon atoms, an unsubstituted cycloalkyl of 5 to 8 carbon atoms, benzyl, or 3,4-dichloro phenyl or 4-methoxy phenyl R 1  is halo; R is hydrogen, halogen or (C 1  -C 4 ) alkyl, and from 90 to 99.5% by weight of dipropylene glycol, polypropylene glycol,   
     
     
        1,5-pentanediol or benzyl alcohol. .Iaddend. .Iadd.11.  The solution of claim 10 wherein the isothiazolone is 5-chloro-2-methyl-4-isothiazolin-3-one. .Iaddend. .Iadd.12. The solution of claim 10 wherein the solvent is dipropylene glycol. .Iaddend. 
     
     
        .Iadd.     A method for stabilizing a 0.5 to about 10% by weight solution of an isothiazolone of the formula: ##STR7## wherein Y is an unsubstituted alkyl of 1 to 8 carbon atoms, an unsubstituted or halo substituted alkenyl or alkynyl of 2 to 8 carbon atoms, an unsubstituted cycloalkyl of 5 to 8 carbon atoms, benzyl, aralkyl selected from 3,4-dichlorobenzyl, 4-methoxybenzyl or 4-chlorobenzyl or substituted aryl selected from 3,4-dichlorophenyl or 4-methoxyphenyl; R 1  is halo; R is hydrogen, halogen or (C 1  -C 4 ) alkyl which consists of formulating a solution of the isothiazolone by dissolving the isothiazolone in from about 90 to about 99% by weight of a solvent selected from the group consisting of ethylene glycol, dipropylene glycol, polypropylene glycol, 1,5-pentanediol, propylene glycol, diethylene glycol, and triethylene glycol, in the absence of water. .Iaddend. 
     
     
        .Iadd.  .  A stabilized solution consisting of essentially from 0.5 to 10% by weight of a compound of the formula: ##STR8## wherein Y is an unsubstituted alkyl of 1 to 8 carbon atoms, an unsubstituted or halo substituted alkenyl or alkynyl group of 2 to 8 carbon atoms, an unsubstituted cycloalkyl of 5 to 8 carbon atoms, benzyl, or 3,4-dichlorobenzyl, 4-methoxybenzyl; R 1  is halo; R is hydrogen, halogen or (C 1  -C 4 ) alkyl, and from 90 to 99% by weight of a solvent selected from the group consisting of ethylene glycol, dipropylene glycol, polypropylene glycol, 1,5-pentanediol, propylene glycol, diethylene glycol and triethylene glycol, said solution containing no 
     
     
        water. .Iaddend. .Iadd.15.  The solution of claim 14 wherein said compound is 5-chloro-2-methyl-4-isothiazoline-3-one. .Iaddend.