Microbicidal composition

1. A microbicidal composition comprising:

(a) 1,2-benzisothiazolin-3-one; and

(b) at least one microbicide selected from the group consisting of benzalkonium chloride, benzethonium chloride, benzyl alcohol, caprylyl glycol, chlorphenesin, diazolidinyl urea, ethylparaben, imidazolidinyl urea, methylparaben, phenoxyethanol, linoleamidopropyl PG-dimonium chloride phosphate, cocamidopropyl PG-dimonium chloride phosphate, propylparaben, Cis-1-(3-chloroallyl)-3,5,7-triaza-1-azoniaadamantane chloride, dehydroacetic acid or its salts, benzoic acid or its salts, and sodium hydroxymethylglycinate

wherein a weight ratio of 1,2-benzisothiazolin-3-one to benzalkonium chloride is from 1:0.025 to 1:40, a weight ratio of 1,2-benzisothiazolin-3-one to benzethonium chloride is from 1:0.13 to 1:3, a weight ratio of 1,2-benzisothiazolin-3-one to benzyl alcohol is from 1:0.4 to 1:35, a weight ratio of 1,2-benzisothiazolin-3-one to caprylyl glycol is from 1:0.7 to 1:67, a weight ratio of 1,2-benzisothiazolin-3-one to chlorphenesin is from 1:20 to 1:50, a weight ratio of 1,2-benzisothiazolin-3-one to diazolidinyl urea is from 1:1 to 1:100, a weight ratio of 1,2-benzisothiazolin-3-one to ethylparaben is from 1:13 to 1:400, a weight ratio of 1,2-benzisothiazolin-3-one to imidazolidinyl urea is from 1:20 to 1:30, a weight ratio of 1,2-benzisothiazolin-3-one to methylparaben is from 1:3 to 1:240, a weight ratio of 1,2-benzisothiazolin-3-one to phenoxyethanol is from 1:2.5 to 1:800, a weight ratio of 1,2-benzisothiazolin-3-one to linoleamidopropyl PG-dimonium chloride phosphate is from 1:0.5 to 1:800, a weight ratio of 1,2-benzisothiazolin-3-one to cocamidopropyl PG-dimonium chloride phosphate is from 1:1.3 to 1:800, a weight ratio of 1,2-benzisothiazolin-3-one to propylparaben is from 1:13 to 1:320, a weight ratio of 1,2-benzisothiazolin-3-one to Cis-1-(3-chloroallyl)-3,5,7-triaza-1-azoniaadamantane chloride is from 1:4 to 1:240, a weight ratio of 1,2-benzisothiazolin-3-one to dehydroacetic acid or its salts is from 1:0.4 to 1:5, a weight ratio of 1,2-benzisothiazolin-3-one to benzoic acid or its salts is from 1:5 to 1:2000, and a weight ratio of 1,2-benzisothiazolin-3-one to sodium hydroxymethylglycinate is from 1:27 to 1:100.

2. A microbicidal composition comprising:

(a) 2-methyl-4-isothiazolin-3-one; and

(b) at least one microbicide selected from the group consisting of caprylyl glycol, chlorphenesin, hexamidine diisethionate, hexetidine, linoleamidopropyl PG-dimonium chloride phosphate, cocamidopropyl PG-dimonium chloride phosphate and dehydroacetic acid or its salts

wherein a weight ratio of 2-methyl-4-isothiazolin-3-one to caprylyl glycol is from 1:0.5 to 1:20, a weight ratio of 2-methyl-4-isothiazolin-3-one to chlorphenesin is from 1:1.2 to 1:600, a weight ratio of 2-methyl-4-isothiazolin-3-one to hexamidine diisethionate is from 1:0.001 to 1:60, a weight ratio of 2-methyl-4-isothiazolin-3-one to hexetidine is from 1:0.002, to 1:250, a weight ratio of 2-methyl-4-isothiazolin-3-one to linoleamidopropyl PG-dimonium chloride phosphate is from 1:0.3 to 1:600, a weight ratio of 2-methyl-4-isothiazolin-3-one to cocamidopropyl PG-dimonium chloride phosphate is from 1:0.03 to 1:80, a weight ratio of 2-methyl-4-isothiazolin-3-one to dehydroacetic acid or its salts is from 1:0.25 to 1:3.