Synergetic Biocidal Compositions Comprising 5-Chlorine-2-Methylisothiazolin-3-One

Abstract

The present invention relates to a biocidal composition, which contains 5-chloro-2-methylisothiazolin-3-one and at least one further component chosen from the group consisting of 3-iodo-2-propanyl butylcarbamate, octylisothiazolinone, n-butyl-benzisothiazolinone, phenetyl alcohol, methylparaben, ethylparaben, benzoic acid, sorbic acid, salicylic acid, dehydracetic acid, didecyldimethylammonium chloride, benzalkonium chloride, formaldehyde, glutaraldehyde, (1-hydroxyethylidene)bis-phosphonic acid, N,N-ethylenediamine disuccinate, and polyaspartic acid. The biocidal composition according to the invention is characterized in that it contains methyl-4-isothiazolin-3-one in the range of between 0 and 2 wt. %, in relation to the total amount of 5-chloro-2-methyl-4-isothiazolin-3-one. The invention further relates to the use of the biocidal compositions according to the invention for preserving technical products.

Claims

1. A biocidal composition containing 5-chloro-2-methylisothiazolin-3-one and at least one further component chosen from the group of 3-iodo-2-propynyl butylcarbamate, octylisothiazolinone, N-butyl-benzisothiazolinone, phenetyl alcohol, methylparaben, ethylparaben, benzoic acid, sorbic acid or salts thereof, salicylic acid or salts thereof, dehydracetic acid or salts thereof, didecyldimethylammonium chloride, benzalkonium chloride, formaldehyde, glutardialdehyde, (1-hydroxyethylidene)bis-phosphonic acid, ethylenediamine disuccinate, polyaspartic acid, characterized in that the composition contains methyl-4-isothiazolin-3-one in the range of 0 to 2 wt. %, in relation to the total amount of the 5-chloro-2-methyl-4-isothiazolin-3-one.

2. The biocidal composition according to claim 1, characterized in that the weight ratio of 5-chloro-2-methylisothiazolin-3-one to 3-iodo-2-propynyl butylcarbamate lies in the range of 3:1 to 1:3,000, in that the weight ratio of 5-chloro-2-methylisothiazolin-3-one to octylisothiazolinone lies in the range of 8:1 to 1:800, in that the weight ratio of 5-chloro-2-methylisothiazolin-3-one to N-butyl-benzisothiazolinone lies in the range of 3:1 to 1:60, in that the weight ratio of 5-chloro-2-methylisothiazolin-3-one to phenetyl alcohol lies in the range of 1:167 to 1:4,000, in that the weight ratio of 5-chloro-2-methylisothiazolin-3-one to 2,2-methylparaben lies in the range of 1:125 to 1:750, in that the weight ratio of 5-chloro-2-methylisothiazolin-3-one to ethylparaben lies in the range of 1:83 to 1:2,000, in that the weight ratio of 5-chloro-2-methylisothiazolin-3-one to benzoic acid lies in the range of 1:167 to 1:2,000, in that the weight ratio of 5-chloro-2-methylisothiazolin-3-one to sorbic acid lies in the range of 1:63 to 1:2,000, in that the weight ratio of 5-chloro-2-methylisothiazolin-3-one to salicylic acid lies in the range of 1:63 to 1:4,000, in that the weight ratio of 5-chloro-2-methylisothiazolin-3-one to dehydracetic acid lies in the range of 1:33 to 1:600, in that the weight ratio of 5-chloro-2-methylisothiazolin-3-one to didecyldimethylammonium chloride lies in the range of 3:1 to 1:20, in that the weight ratio of 5-chloro-2-methylisothiazolin-3-one to benzalkonium chloride lies in the range of 1:3 to 1:40, in that the weight ratio of 5-chloro-2-methylisothiazolin-3-one to formaldehyde lies in the range of 1:10 to 1:1,000, in that the weight ratio of 5-chloro-2-methylisothiazolin-3-one to glutardialdehyde lies in the range of 1:21 to 1:500, in that the weight ratio of 5-chloro-2-methylisothiazolin-3-one to (1-hydroxyethylidene)bis-phosphonic acid lies in the range of 1:11 to 1:500, in that the weight ratio of 5-chloro-2-methylisothiazolin-3-one to ethylenediamine disuccinate lies in the range of 1:104 to 1:10,000, and in that the weight ratio of 5-chloro-2-methylisothiazolin-3-one to polyaspartic acid (as Na salt) lies in the range of 1:208 to 1:6,667.

3. The biocidal composition according to claim 1, characterized in that it contains the 5-chloro-2-methylisothiazolin-3-one and the at least one further biocide in a total concentration of 0.5 to 50 wt. %, in relation to the total biocide composition.

4. The biocidal composition according to claim 1, characterized in that it comprises a polar and a nonpolar medium.

5. The biocidal composition according to claim 4, characterized in that it comprises, as polar liquid medium, water, an aliphatic alcohol with 1 to 4 carbon atoms, a glycol, a glycol ether, a glycol ester, a polyethylene glycol, a propylene glycol, N,N-dimethylformamide, 2,2,4-trimethylpentandiolmonoisobutyrate or a mixture thereof.

6. The biocidal composition according to claim 1, characterized in that it is present in the form of a liquid preparation.

7. Use of the biocidal composition according claim 1 for in-can preservation.

8. The use of the biocidal composition according to claim 7 for the in-can preservation of coating materials such as paints, varnishes and plaster, of polymer dispersions, emulsions, latexes and adhesives.

9. A preserved product, containing a biocidal composition as described in claim 1.

10. The preserved product according to claim 9, selected from lignin sulfonates and starch preparations in coating materials, paints, varnishes, glazes and plasters, emulsions, latexes, polymer dispersions, chalk slurries, mineral slurries, ceramic materials, adhesives, fragrances, casein-containing products, starch-containing products, bitumen emulsions, surfactant solutions, fuels, cleaning agents, pigment pastes and pigment dispersions, inks, lithographic liquids, thickeners, cosmetic products, toilet articles, water systems, fluids in wood working, fluids in oil extraction, fluids in paper processing, fluids in leather production, fluids in textile production, drilling and cutting oils, hydraulic fluids and cooling lubricants.

Description

THE FOLLOWING EXAMPLES SERVE TO FURTHER EXPLAIN THE PRESENT INVENTION

Examination of the Synergetic Effect

[0103] The synergism of a combination of 5-chloro-2-methylisothiazolin-3-one, containing 0.003 wt. %, in relation to the total amount of 5-chloro-2-methyl-4-isothiazolin-3-one, of 2-methylisothiazolin-3-one, with a biocide/a compound selected from the group consisting of 3-iodo-2-propynyl butylcarbamate (IPBC), octylisothiazolinone (OIT), N-butyl-benzisothiazolinone, phenetyl alcohol, methylparaben, ethylparaben, benzoic acid, sorbic acid, salicylic acid, dehydracetic acid, didecyldimethylammonium chloride (DDAC), benzalkonium chloride (BAC), formaldehyde, glutardialdehyde, (1-hydroxyethylidene)bis-phosphonic acid (HEDP), ethylenediamine disuccinate (EDDS) and polyaspartic acid (PASP), was investigated for a synergetic interaction.

[0104] The test organisms used were the Gram-negative bacterium Pseudomonas putida (DSM 25068) and the yeast fungus Yarrowia lipolytica (DSM 32369). For this, mixtures with different concentrations of the particular active substances were prepared and tested in regard to their effect on Pseudomonas putida and Yarrowia lipolytica. The testing was done in Milller-Hinton broth MHB (in the case of Pseudomonas) or Sabouraud Maltose broth SMB (in the case of Yarrowia) with a cell density of 10.sup.6 germs per ml.

[0105] The incubation time of the microtiter plates was 48 hours at 30 C. (Pseudomonas) or 25 C. (Yarrowia). After 48 hours the batches were evaluated for turbidity due to growth and, in addition, the optical density was determined by photometry. In this way, the minimum inhibitory concentrations (MHK) were determined for the two active substances individually and in combination.

[0106] The resulting synergism was represented numerically by calculating the synergy index (SI). The calculation was done by the customary method of F. C. Kull et al., Applied Microbiology, Vol. 9 (1961), p. 538. There, the SI is calculated by the following formula: synergy index SI =Qa/QA +Qb/QB

[0107] Qa =concentration of component A in the mixture A+B

[0108] QA =concentration of component A as sole biocide

[0109] Qb =concentration of component B in the mixture A+B

[0110] QB =concentration of component B as sole biocide

[0111] If the synergy index has a value over 1, this means that an antagonism is present. If the synergy index takes on the value 1, this means that an addition of the effect of the two biocides/compounds is present. If the synergy index takes on a value below 1, this means that a synergism exists for the two biocides. If the synergy index has a value of more than 1, this means that an antagonism exists.

EXAMPLE 1a

Examination of the Synergetic Interaction Between chloro-2-methyl-4-isothiazolin-3-one (CMIT) and 3-iodo-2-propynyl butylcarbamate (IPBC)

[0112] Calculation of the synergy index of chloro-2-methyl-4-isothiazolin-3-one (CMIT) and IPBC with regard to Pseudomonas putida at an incubation time of 48 hours at 30 C.

TABLE-US-00001 TABLE 1a Synergy index Qa/QA + Qa (CIT) [ppm] Qb (IPBC) [ppm] Qb/QB 0 1000 1.00 0.25 750 0.88 0.5 500 0.75 0.75 300 0.68 1 200 0.70 1.5 100 0.85 2 0 1.00 Qa: Concentration of CMIT in the mixture indicating an end point QA: Concentration of CMIT as sole agent indicating an end point Qb: Concentration of IPBC in the mixture indicating an end point QB: Concentration of IPBC as sole agent indicating an end point

[0113] It is evident from Table 1a that the optimal synergism, i.e. the lowest synergy index (0.68) of a biocidal composition of CMIT and IPBC lies at a ratio of 0.75 ppm CMIT to 300 ppm IPBC. A synergism can be demonstrated if the weight ratio of the biocides CMIT and IPBC lies in the range of 1:67 to 1:3,000.

Example 1b

Examination of the Synergetic Interaction Between chloro-2-methyl-4-isothiazolin-3-one (CMIT) and 3-iodo-2-propynyl butylcarbamate (IPBC)

[0114] Calculation of the synergy index of chloro-2-methyl-4-isothiazolin-3-one (CMIT) and IPBC with regard to Yarrowia lipolytica at an incubation time of 48 hours at 25 C.

TABLE-US-00002 TABLE 1b Qa (CIT) Qb (IPBC) Synergy index [ppm] [ppm] Qa/QA + Qb/QB 0.00 2.50 1.00 0.50 1.75 0.90 0.75 1.25 0.80 0.75 1.00 0.70 0.75 0.75 0.60 1.00 0.75 0.70 1.50 0.50 0.80 2.50 0.00 1.00 Qa: Concentration of CMIT in the mixture indicating an end point QA: Concentration of CMIT as sole agent indicating an end point Qb: Concentration of IPBC in the mixture indicating an end point QB: Concentration of IPBC as sole agent indicating an end point

[0115] It is evident from Table 1b that the optimal synergism, i.e. the lowest synergy index (0.60) of a biocidal composition of CMIT and IPBC lies at a ratio of 0.75 ppm CMIT to 0.75 ppm IPBC. A synergism can be demonstrated if the weight ratio of the biocides CMIT and IPBC lies in the range of 3:1 to 1:3.5.

EXAMPLE 2a

Examination of the Synergetic Interaction Between chloro-2-methyl-4-isothiazolin-3-one (CMIT) and octylisothiazolinone (OIT)

[0116] Calculation of the synergy index of chloro-2-methyl-4-isothiazolin-3-one (CMIT) and octylisothiazolinone (OIT) with regard to Pseudomonas putida at an incubation time of 48 hours at 30 C.

TABLE-US-00003 TABLE 2a Qa (CIT) Synergy index [ppm] Qb (OIT) [ppm] Qa/QA + Qb/QB 0 300 1.00 0.25 200 0.79 0.5 150 0.75 0.75 100 0.71 1 100 0.83 1.5 50 0.92 2 0 1.00 Qa: Concentration of CMIT in the mixture indicating an end point QA: Concentration of CMIT as sole agent indicating an end point Qb: Concentration of OIT in the mixture indicating an end point QB: Concentration of OIT as sole agent indicating an end point

[0117] It is evident from Table 2a that the optimal synergism, i.e. the lowest synergy index (0.71) of a biocidal composition of CMIT and OIT, lies at a ratio of 0.75 ppm CMIT to 100 ppm OIT. A synergism can be demonstrated if the weight ratio of the biocides CMIT and OIT lies in the range of 1:33 to 1:800.

EXAMPLE 2b

Examination of the Synergetic Interaction Between chloro-2-methyl-4-isothiazolin-3-one (CMIT) and octylisothiazolinone (OIT)

[0118] Calculation of the synergy index of chloro-2-methyl-4-isothiazolin-3-one (CMIT) and octylisothiazolinone (OIT) with regard to Yarrowia lipolytica at an incubation time of 48 hours at 25 C.

TABLE-US-00004 TABLE 2b Qa (CIT) Qb (OIT) Synergy index [ppm] [ppm] Qa/QA + Qb/QB 0.00 2.00 1.00 0.25 1.50 0.85 0.50 1.00 0.70 0.75 1.00 0.80 0.75 0.75 0.68 1.00 0.50 0.65 1.50 0.25 0.73 2.00 0.25 0.93 2.50 0.00 1.00 Qa: Concentration of CMIT in the mixture indicating an end point QA: Concentration of CMIT as sole agent indicating an end point Qb: Concentration of OIT in the mixture indicating an end point QB: Concentration of OIT as sole agent indicating an end point

[0119] It is evident from Table 2b that the optimal synergism, i.e. the lowest synergy index (0.65) of a biocidal composition of CMIT and OIT lies at a ratio of 1 ppm CMIT to 0.5 ppm OIT. A synergism can be demonstrated if the weight ratio of the biocides CMIT and OIT lies in the range of 8:1 to 1:6.

EXAMPLE 3a

Examination of the Synergetic Interaction Between chloro-2-methyl-4-isothiazolin-3-one (CMIT) and N-butyl-benzisothiazolinone (BBIT)

[0120] Calculation of the synergy index of chloro-2-methyl-4-isothiazolin-3-one (CMIT) and N-butyl-benzisothiazolinone (BBIT) with regard to Pseudomonas putida at an incubation time of 48 hours at 30 C.

TABLE-US-00005 TABLE 3a Qa (CIT) Synergy index [ppm] Qb (BBIT) [ppm] Qa/QA + Qb/QB 0 20 1.00 0.25 15 0.88 0.25 10 0.63 0.5 7.5 0.63 0.75 5 0.63 0.75 3 0.53 1 3 0.65 1.5 1 0.80 2 0 1.00 Qa: Concentration of CMIT in the mixture indicating an end point QA: Concentration of CMIT as sole agent indicating an end point Qb: Concentration of BBIT in the mixture indicating an end point QB: Concentration of BBIT as sole agent indicating an end point

[0121] It is evident from Table 3a that the optimal synergism, i.e. the lowest synergy index (0.53) of a biocidal composition of CMIT and BBIT lies at a ratio of 0,75 ppm CMIT to 3 ppm BBIT. A synergism can be demonstrated if the weight ratio of the biocides CMIT and BBIT lies in the range of 1:0.67 to 1:60.

EXAMPLE 3b

Examination of the Synergetic Interaction Between chloro-2-methyl-4-isothiazolin-3-one (CMIT) and N-butyl-benzisothiazolinone (BBIT)

[0122] Calculation of the synergy index of chloro-2-methyl-4-isothiazolin-3-one (CMIT) and N-butyl-benzisothiazolinone (BBIT) with regard to Yarrowia lipolytica at an incubation time of 48 hours at 25 C.

TABLE-US-00006 TABLE 3b Qa (CIT) Qb (BBIT) Synergy index [ppm] [ppm] Qa/QA + Qb/QB 0.00 3.00 1.00 0.50 2.00 0.87 0.50 1.50 0.70 0.75 1.00 0.63 1.00 0.75 0.65 1.50 0.50 0.77 2.50 0.00 1.00 Qa: Concentration of CMIT in the mixture indicating an end point QA: Concentration of CMIT as sole agent indicating an end point Qb: Concentration of BBIT in the mixture indicating an end point QB: Concentration of BBIT as sole agent indicating an end point

[0123] It is evident from Table 3b that the optimal synergism, i.e. the lowest synergy index (0.63) of a biocidal composition of CMIT and BBIT lies at a ratio of 0.75 ppm CMIT to 1 ppm BBIT. A synergism can be demonstrated if the weight ratio of the biocides CMIT and BBIT lies in the range of 3:1 to 1:4.

EXAMPLE 4

Examination of the Synergetic Interaction Between chloro-2-methyl-4-isothiazolin-3-one (CMIT) and Phenetyl Alcohol

[0124] Calculation of the synergy index of chloro-2-methyl-4-isothiazolin-3-one (CMIT) and 2,2-phenetyl alcohol with regard to Pseudomonas putida at an incubation time of 48 hours at 30 C.

TABLE-US-00007 TABLE 4 Qa (CMIT) Qb (phenetyl alcohol) Synergy index [ppm] [ppm] Qa/QA + Qb/QB 0 3000 1.00 0.5 2000 0.92 0.75 1000 0.71 0.75 750 0.63 0.75 500 0.54 1 500 0.67 1.5 250 0.83 2 0 1.00 Qa: Concentration of CMIT in the mixture indicating an end point QA: Concentration of CMIT as sole agent indicating an end point Qb: Concentration of phenetyl alcohol in the mixture indicating an end point QB: Concentration of phenetyl alcohol as sole agent indicating an end point

[0125] It is evident from Table 4 that the optimal synergism, i.e. the lowest synergy index (0.54) of a biocidal composition of CMIT and phenetyl alcohol, lies at a ratio of 0.75 ppm CMIT to 500 ppm phenetyl alcohol. A synergism can be demonstrated if the weight ratio of the biocides CMIT and phenetyl alcohol lies in the range of 1:167 to 1:4,000.

EXAMPLE 5

Examination of the Synergetic Interaction Between chloro-2-methyl-4-isothiazolin-3-one (CMIT) and Methylparaben

[0126] Calculation of the synergy index of chloro-2-methyl-4-isothiazolin-3-one (CMIT) and methylparaben with regard to Pseudomonas putida at an incubation time of 48 hours at 30 C.

TABLE-US-00008 TABLE 5 Qa (CMIT) Qb (methylparaben) Synergy index Qa/QA + [ppm] [ppm] Qb/QB 0 2000 1.00 1 750 0.88 1 500 0.75 2 250 0.88 2 0 1.00 Qa: Concentration of CMIT in the mixture indicating an end point QA: Concentration of CMIT as sole agent indicating an end point Qb: Concentration of methylparaben in the mixture indicating an end point QB: Concentration of methylparaben as sole agent indicating an end point

[0127] It is evident from Table 5 that the optimal synergism, i.e. the lowest synergy index (0.75) of a biocidal composition of CMIT and methylparaben lies at a ratio of 1 ppm CMIT to 500 ppm methylparaben. A synergism can be demonstrated if the weight ratio of the biocides CMIT and methylparaben lies in the range of 1:125 to 1:750.

EXAMPLE 6

Examination of the Synergetic Interaction Between chloro-2-methyl-4-isothiazolin-3-one (CMIT) and Ethylparaben

[0128] Calculation of the synergy index of chloro-2-methyl-4-isothiazolin-3-one (CMIT) and ethylparaben with regard to Pseudomonas putida at an incubation time of 48 hours at 30 C.

TABLE-US-00009 TABLE 6 Qa (CMIT) Qb (ethylparaben) Synergy index [ppm] [ppm] Qa/QA + Qb/QB 0 1500 1.00 0.5 1000 0.92 0.5 750 0.75 0.75 500 0.71 0.75 250 0.54 1 125 0.58 1.5 125 0.83 2 0 1.00 Qa: Concentration of CMIT in the mixture indicating an end point QA: Concentration of CMIT as sole agent indicating an end point Qb: Concentration of ethylparaben in the mixture indicating an end point QB: Concentration of ethylparaben as sole agent indicating an end point

[0129] It is evident from Table 6 that the optimal synergism, i.e. the lowest synergy index (0.54) of a biocidal composition of CMIT and ethylparaben lies at a ratio of 0.75 ppm CMIT to 250 ppm ethylparaben. A synergism can be demonstrated if the weight ratio of the biocides CMIT and ethylparaben lies in the range of 1:83 to 1:2,000.

EXAMPLE 7

Examination of the Synergetic Interaction Between chloro-2-methyl-4-isothiazolin-3-one (CMIT) and Benzoic Acid

[0130] Calculation of the synergy index of chloro-2-methyl-4-isothiazolin-3-one (CMIT) and benzoic acid with regard to Yarrowia lipolytica at an incubation time of 48 hours at 25 C.

TABLE-US-00010 TABLE 7 Qa (CMIT) Qb (benzoic acid) Synergy index [ppm] [ppm] Qa/QA + Qb/QB 0 2500 1.00 0.5 1000 0.60 0.75 750 0.60 0.75 500 0.50 1 500 0.60 1 250 0.50 1.5 250 0.70 2.5 0 1.00 Qa: Concentration of CMIT in the mixture indicating an end point QA: Concentration of CMIT as sole agent indicating an end point Qb: Concentration of benzoic acid in the mixture indicating an end point QB: Concentration of benzoic acid as sole agent indicating an end point

[0131] It is evident from Table 7 that the optimal synergism, i.e. the lowest synergy index (0.50) of a biocidal composition of CMIT and benzoic acid lies at a ratio of 1 ppm CMIT to 250 ppm benzoic acid. A synergism can be demonstrated if the weight ratio of the biocides CMIT and benzoic acid lies in the range of 1:167 to 1:2,000.

EXAMPLE 8

Examination of the Synergetic Interaction Between chloro-2-methyl-4-isothiazolin-3-one (CMIT) and Sorbic Acid

[0132] Calculation of the synergy index of chloro-2-methyl-4-isothiazolin-3-one (CMIT) and sorbic acid with regard to Yarrowia lipolytica at an incubation time of 48 hours at 25 C.

TABLE-US-00011 TABLE 8 Qa (CMIT) Qb (sorbic acid) Synergy index [ppm] [ppm] Qa/QA + Qb/QB 0 750 1.00 0.25 500 0.77 0.5 500 0.87 0.75 250 0.63 1 125 0.57 1.5 125 0.77 2 125 0.97 2.5 0 1.00 Qa: Concentration of CMIT in the mixture indicating an end point QA: Concentration of CMIT as sole agent indicating an end point Qb: Concentration of sorbic acid in the mixture indicating an end point QB: Concentration of sorbic acid as sole agent indicating an end point

[0133] It is evident from Table 8 that the optimal synergism, i.e. the lowest synergy index (0.57) of a biocidal composition of CMIT and sorbic acid lies at a ratio of 1 ppm CMIT to 125 ppm sorbic acid. A synergism can be demonstrated if the weight ratio of the biocides CMIT and sorbic acid lies in the range of 1:63 to 1:2,000.

EXAMPLE 9

Examination of the Synergetic Interaction Between chloro-2-methyl-4-isothiazolin-3-one (CMIT) and Salicylic Acid

[0134] Calculation of the synergy index of chloro-2-methyl-4-isothiazolin-3-one (CMIT) and salicylic acid with regard to Yarrowia lipolytica at an incubation time of 48 hours at 25 C.

TABLE-US-00012 TABLE 9 Qa (CMIT) Qb (salicylic acid) Synergy index [ppm] [ppm] Qa/QA + Qb/QB 0 3000 1.00 0.5 2000 0.87 0.5 1000 0.53 0.75 750 0.55 0.75 500 0.47 1 500 0.57 1.5 500 0.77 2 250 0.88 2 125 0.84 2.5 0 1.00 Qa: Concentration of CMIT in the mixture indicating an end point QA: Concentration of CMIT as sole agent indicating an end point Qb: Concentration of salicylic acid in the mixture indicating an end point QB: Concentration of salicylic acid as sole agent indicating an end point

[0135] It is evident from Table 9 that the optimal synergism, i.e. the lowest synergy index (0.47) of a biocidal composition of CMIT and salicylic acid lies at a ratio of 0.75 ppm CMIT to 500 ppm salicylic acid. A synergism can be demonstrated if the weight ratio of the components CMIT and salicylic acid lies in the range of 1:63 to 1:4,000.

EXAMPLE 13

Examination of the Synergetic Interaction Between chloro-2-methyl-4-isothiazolin-3-one (CMIT) and Dehydracetic Acid

[0136] Calculation of the synergy index of chloro-2-methyl-4-isothiazolin-3-one (CMIT) and dehydracetic acid with regard to Yarrowia lipolytica at an incubation time of 48 hours at 25 C.

TABLE-US-00013 TABLE 13 Qa (CMIT) Qb (dehydracetic acid) Synergy index [ppm] [ppm] Qa/QA + Qb/QB 0 200 1.00 0.25 150 0.85 0.5 150 0.95 0.75 100 0.80 1 100 0.90 1.5 50 0.85 2.5 0 1.00 Qa: Concentration of CMIT in the mixture indicating an end point QA: Concentration of CMIT as sole agent indicating an end point Qb: Concentration of dehydracetic acid in the mixture indicating an end point QB: Concentration of dehydracetic acid as sole agent indicating an end point

[0137] It is evident from Table 7 that the optimal synergism, i.e. the lowest synergy index (0.80) of a biocidal composition of CMIT and dehydracetic acid lies at a ratio of 0.75 ppm CMIT to 100 ppm dehydracetic acid. A synergism can be demonstrated if the weight ratio of the components CMIT and dehydracetic acid lies in the range of 1:33 to 1:600.

EXAMPLE 10

Examination of the Synergetic Interaction Between chloro-2-methyl-4-isothiazolin-3-one (CMIT) and Didecyldimethylammonium Chloride (DDAC)

[0138] Calculation of the synergy index of chloro-2-methyl-4-isothiazolin-3-one (CMIT) and didecyldimethylammonium chloride (DDAC) with regard to Pseudomonas putida at an incubation time of 48 hours at 30 C.

TABLE-US-00014 TABLE 10 Qa (CMIT) Qb (DDAC) Synergy index [ppm] [ppm] Qa/QA + Qb/QB 0 7.5 1.00 0.25 5 0.79 0.5 5 0.92 1 2.5 0.83 1 1 0.63 1.5 0.5 0.82 2 0 1.00 Qa: Concentration of CMIT in the mixture indicating an end point QA: Concentration of CMIT as sole agent indicating an end point Qb: Concentration of DDAC in the mixture indicating an end point QB: Concentration of DDAC as sole agent indicating an end point

[0139] It is evident from Table 10 that the optimal synergism, i.e. the lowest synergy index (0.63) of a biocidal composition of CMIT and DDAC lies at a ratio of 1 ppm CMIT to 1 ppm DDAC. A synergism can be demonstrated if the weight ratio of the components CMIT and DDAC lies in the range of 3:1 to 1:20.

EXAMPLE 11

Examination of the Synergetic Interaction Between chloro-2-methyl-4-isothiazolin-3-one (CMIT) and Benzalkonium Chloride (BAC)

[0140] Calculation of the synergy index of chloro-2-methyl-4-isothiazolin-3-one (CMIT) and benzalkonium chloride (BAC) with regard to Pseudomonas putida at an incubation time of 48 hours at 30 C.

TABLE-US-00015 TABLE 11 Qa (CMIT) Qb (BAC) Synergy index [ppm] [ppm] Qa/QA + Qb/QB 0 30 1.00 0.5 20 0.92 0.75 15 0.88 1 10 0.83 1 7.5 0.75 1.5 5 0.92 2 0 1.00 Qa: Concentration of CMIT in the mixture indicating an end point QA: Concentration of CMIT as sole agent indicating an end point Qb: Concentration of BAC in the mixture indicating an end point QB: Concentration of BAC as sole agent indicating an end point

[0141] It is evident from Table 11 that the optimal synergism, i.e. the lowest synergy index (0.75) of a biocidal composition of CMIT and BAC lies at a ratio of 1 ppm CMIT to 7.5 ppm BAC. A synergism can be demonstrated if the weight ratio of the components CMIT and BAC lies in the range of 1:3 to 1:40.

EXAMPLE 12

Examination of the Synergetic Interaction Between chloro-2-methyl-4-isothiazolin-3-one (CMIT) and Formaldehyde (HCHO)

[0142] Calculation of the synergy index of chloro-2-methyl-4-isothiazolin-3-one (CMIT) and formaldehyde (HCHO) with regard to Pseudomonas putida at an incubation time of 48 hours at 30 C.

TABLE-US-00016 TABLE 12 Qa (CMIT) Qb (HCHO) Synergy index [ppm] [ppm] Qa/QA + Qb/QB 0 500 1.00 0.25 250 0.63 0.5 125 0.50 0.75 62.5 0.50 0.75 31.25 0.44 1 31.25 0.56 1.5 15.63 0.78 2 0 1.00 Qa: Concentration of CMIT in the mixture indicating an end point QA: Concentration of CMIT as sole agent indicating an end point Qb: Concentration of HCHO in the mixture indicating an end point QB: Concentration of HCHO as sole agent indicating an end point

[0143] It is evident from Table 12 that the optimal synergism, i.e. the lowest synergy index (0.44) of a biocidal composition of CMIT and HCHO lies at a ratio of 0.75 ppm CMIT to 62.5 ppm HCHO. A synergism can be demonstrated if the weight ratio of the components CMIT and HCHO lies in the range of 1:10 to 1:1,000.

EXAMPLE 13

Examination of the Synergetic Interaction Between chloro-2-methyl-4-isothiazolin-3-one (CMIT) and Glutardialdehyde (GDA)

[0144] Calculation of the synergy index of chloro-2-methyl-4-isothiazolin-3-one (CMIT) and glutardialdehyde (GDA) with regard to Pseudomonas putida at an incubation time of 48 hours at 30 C.

TABLE-US-00017 TABLE 13 Qa (CMIT) Qb (GDA) Synergy index [ppm] [ppm] Qa/QA + Qb/QB 0 500 1.00 0.5 250 0.75 0.5 125 0.50 0.5 62.5 0.38 1 62.5 0.63 1.5 31.25 0.81 2 0 1.00 Qa: Concentration of CMIT in the mixture indicating an end point QA: Concentration of CMIT as sole agent indicating an end point Qb: Concentration of GDA in the mixture indicating an end point QB: Concentration of GDA as sole agent indicating an end point

[0145] It is evident from Table 13 that the optimal synergism, i.e. the lowest synergy index (0.38) of a biocidal composition of CMIT and GDA lies at a ratio of 1 ppm CMIT to 125 ppm GDA. A synergism can be demonstrated if the weight ratio of the components CMIT and GDA lies in the range of 1:21 to 1:500.

EXAMPLE 14

Examination of the Synergetic Interaction Between chloro-2-methyl-4-isothiazolin-3-one (CMIT) and (1-hydroxyethylidene)bis-phosphonic Acid (HEDP)

[0146] Calculation of the synergy index of chloro-2-methyl-4-isothiazolin-3-one (CMIT) and (1-hydroxyethylidene)bis-phosphonic acid (HEDP) with regard to Pseudomonas putida at an incubation time of 48 hours at 30 C.

TABLE-US-00018 TABLE 14 Qa (CMIT) Qb (HEDP) Synergy index [ppm] [ppm] Qa/QA + Qb/QB 0 250 1.00 0.25 125 0.63 0.5 31.25 0.38 0.75 31.25 0.50 1 15.63 0.56 1.5 16.63 0.82 2 0 1.00 Qa: Concentration of CMIT in the mixture indicating an end point QA: Concentration of CMIT as sole agent indicating an end point Qb: Concentration of HEDP in the mixture indicating an end point QB: Concentration of HEDP as sole agent indicating an end point

[0147] It is evident from Table 14 that the optimal synergism, i.e. the lowest synergy index (0.38) of a biocidal composition of CMIT and HEDP lies at a ratio of 0.5 ppm CMIT to 31.25 ppm HEDP. A synergism can be demonstrated if the weight ratio of the components CMIT and HEDP lies in the range of 1:11 to 1:500.

EXAMPLE 15

Examination of the Synergetic Interaction Between chloro-2-methyl-4-isothiazolin-3-one (CMIT) and Ethylenediamine Disuccinate (EDDS)

[0148] Calculation of the synergy index of chloro-2-methyl-4-isothiazolin-3-one (CMIT) and ethylenediamine disuccinate (EDDS) with regard to Pseudomonas putida at an incubation time of 48 hours at 30 C.

TABLE-US-00019 TABLE 15 Qa (CMIT) Qb (EDDS) Synergy index [ppm] [ppm] Qa/QA + Qb/QB 0 5000 1.00 0.25 2500 0.63 0.5 1250 0.50 0.75 312.5 0.44 0.75 156.25 0.41 1 156.25 0.53 1.5 156.25 0.78 2 0 1.00 Qa: Concentration of CMIT in the mixture indicating an end point QA: Concentration of CMIT as sole agent indicating an end point Qb: Concentration of EDDS in the mixture indicating an end point QB: Concentration of EDDS as sole agent indicating an end point

[0149] It is evident from Table 15 that the optimal synergism, i.e. the lowest synergy index (0.41) of a biocidal composition of CMIT and EDDS lies at a ratio of 0.75 ppm CMIT to 156.25 ppm EDDS. A synergism can be demonstrated if the weight ratio of the components CMIT and EDDS lies in the range of 1:104 to 1:10,000.

EXAMPLE 16

Examination of the Synergetic Interaction Between chloro-2-methyl-4-isothiazolin-3-one (CMIT) and Polyaspartic Acid (PASP)

[0150] Calculation of the synergy index of chloro-2-methyl-4-isothiazolin-3-one (CMIT) and polyaspartic acid Na salt (PASP Na salt)with regard to Pseudomonas putida at an incubation time of 48 hours at 30 C.

TABLE-US-00020 TABLE 16 Qa (CMIT) Qb (PASP Na salt) Synergy index [ppm] [ppm] Qa/QA + Qb/QB 0 10000 1.00 0.75 5000 0.88 1 2500 0.75 1 1250 0.63 1 625 0.56 1.5 312.5 0.78 2 0 1.00 Qa: Concentration of CMIT in the mixture indicating an end point QA: Concentration of CMIT as sole agent indicating an end point Qb: Concentration of PASP Na salt in the mixture indicating an end point QB: Concentration of PASP Na salt as sole agent indicating an end point

[0151] It is evident from Table 16 that the optimal synergism, i.e. the lowest synergy index (0.56) of a biocidal composition of CMIT and PASP Na salt lies at a ratio of 1 ppm CMIT to 625 ppm PASP Na salt. A synergism can be demonstrated if the weight ratio of the components CMIT and PASP Na salt lies in the range of 1:208 to 1:6,667.