WO1998047359A1

WO1998047359A1 - Rapid and long lasting biocidal system

Info

Publication number: WO1998047359A1
Application number: PCT/GB1998/001176
Authority: WO
Inventors: John Frederick Carr; Brian Davis; Peter Jordan
Original assignee: Rhodia Ltd
Current assignee: Rhodia Ltd
Priority date: 1997-04-22
Filing date: 1998-04-22
Publication date: 1998-10-29
Anticipated expiration: 1999-10-22
Also published as: GB9708067D0; AU7066998A; GB2324467A

Abstract

A rapidly active and long lasting biocide system (BS) comprising at least one watersoluble or waterdispersible monoquaternary ammonium or phosphonium salt biocidal agent or monoquaternary heterocyclic amine salt biocidal agent (M); and at least one watersoluble or waterdispersible polymeric quaternary ammonium salt, polymeric quaternary heterocyclic amine salt or polymeric cationic biguanide salt (P) and biocidal aqueous compositions comprising said biocide system.

Description

RAPID AND LONG LASTING BIOCIDAL SYSTEM

The invention relates to a rapid and long lasting biocide system, to its use in biocidal aqueous compositions, particularly for the biocidal treatment of hard surfaces, and to a method for rapid and long lasting biocidal treatment of hard surfaces.

Monoquaternary ammonium or phosphonium salt biocides and monoquaternary heterocyclic amine salt biocides are known as having rapid activity particularly when applied on hard surfaces, but they suffer from the disadvantage of having to be used in relatively high amounts.

It has been proposed, in order to control biocide release, to provide a liquid biocidal composition containing the biocide and a film forming polymer or copolymer such as polyvinylpyrrolidone, copolymers of vinylpyrrolidone and vinyl acetate, copolymers of vinyl ethers and maleic anhydride (GB-A-1 553 132) , acrylic or methacrylic copolymers (EP-A-0 290 676) or terephthalic copolyesters (WO 97/06675) . The polymer or copolymer film formed on the hard surface holds and protects the biocide, which is slowly released to give extended disinfectancy, by resistance to washing.

Such compositions suffer the disadvantage that they contain a relatively high concentration of polymer compared to the concentration of biocide; besides the increase in cost, this prevents the provision of rapid disinfection. Further it may also create problems in formulation because most of these polymers are insoluble in water, and thus difficult to formulate in aqueous products.

Thus, a need exists for a biocidal product and a biocidal composition capable of being both rapid acting and long lasting and which can be used at low level.

According to the present invention, there is provided a biocidal system which is able to provide both in-built rapid acting disinfection (for example as little as 5 minutes after having been applied to a hard surface) and in-built extended disinfectancy (for example 24 hours, indeed 3 days or more after having been applied to said hard surface) . This biocidal system is composed of a combination of a monocationic salt biocidal agent and a polymeric cationic salt compound; isobolograms show that the agent and compound mutually support each other very significantly in their effects and that a lower concentration of biocide is required to achieve the same effect; impact on the environment is thus reduced. Further, said biocidal system is easy to formulate, particularly in non-ionic active cleaners.

According to the present invention, there is provided a rapidly active and long lasting biocide system (BS) in the form of an aqueous solution comprising water, as solvent, and at least 1% by weight of at least one watersoluble first biocidal agent which is a monoquaternary ammonium or phosphonium salt or a monoquaternary heterocyclic amine salt (M) ; and at least 3% by weight of at least one watersoluble second biocidal agent which is a polymeric quaternary ammonium salt, polymeric quaternary heterocyclic amine salt or polymeric cationic biguanide salt (P) .

Preferably at least one non-ionic, amphoteric or zwitterionic surfactant is present .

The present invention also provides the use in a biocidal aqueous composition (BAC) , of a biocide system (BS) as defined above as well as a method for the biocidal treatment of a hard surface which comprises applying to said surface a biocidal aqueous composition (BAC) as defined above.

The (BAC) is preferably a hard surface treatment or cleaning composition.

Suitable biocidal agents include:

-mono- or -di- (higher alkyl) quaternary ammonium salts such as N-higher alkyl-N-aryl-N, N-di (lower alkyl) ammonium salts such as

R¹R²R³R⁴N⁺X^" where

R¹ is optionally chloro substituted benzyl, or C₁-C₄ alkyl benzyl,

R² is C₈-C₂₄ alkyl,

R³ and R⁴ are each independently C^C, alkyl or C_!-C₄ hydroxyalkyl , and X^" is a water solubilising anion such halide (e.g. chloride, bromide, iodide), sulfate, or methylsulfate . Generally "lower alkyl" as used herein, means alkyl of 1 to 4 carbon atoms while "higher alkyl" means alkyl of at least 8 carbon atoms .

Specific examples include coco-alkyl benzyl dimethylammonium chloride, C₁₂-C₁₄ alkyl benzyl dimethyl ammonium chloride, coco-alkyl dichlorobenzyl dimethylammonium chloride and tetradecyl benzyl dimethylammonium chloride .

*N,N-di (higher alkyl) -N,N-di (lower alkyl) ammonium salt such as

where

R¹ and R² are each independently, C₈-C₂₄ alkyl,

R^3' and R^4' are each independently, C^C, alkyl, and

X^" is a water solubilising anion such as defined above, such as dodecyl dimethylammonium chloride and dioctyl dimethylammonium chloride .

*N-higher alkyl-N,N,N-tri (lower alkyl) ammonium salts such as R^1"R^2"R^3"R^4,,N⁺X^" where

R^1" is C₈-C₂₄ alkyl R^2", R³ and R⁴ are each independently Cj-C, alkyl, and X^" is a water solubilising anion such as defined above such as myristyl trimethylammonium bromide and cetyl trimethylammonium bromide.

- monoquaternary heterocyclic amine salts such as laurylpyridinium chloride, cetylpyridinium chloride, C₁₂- C₁₄-alkyl-benzyl imidazolinium chloride. higher alkyl triphenyl phosphonium salts wherein the anion is generally a water solubilising anion as defined for X, such as -myristyl triphenyl phosphonium bromide.

(P) is water soluble and is a biocide such as: polymers from the reaction of

*epichlorhydrin and dimethylamine or diethylamine e.g. poly [hydroxyethylene (dimethylamino) -2- hydroxypropyl (dimethylamino) methylene dichloride] ;

*epichlorhydrin and imidazole;

*1, 3-dichloro-2-propanol and dimethylamine; *1, 3-dichloro-2-propanol and 1 , 3-bis-dimethylamino-2- propanol ;

*ethylene dichloride and 1, 3 -bis-dimethylamino-2 -propanol ;

*bis (2-chloroethyl) ether and N, N,N', N¹-tetramethylethylene diamine e.g. polyoxyethylene (dimethylamino) ethylene (dimethylamino) dichloride;

*bis (2-chloroethyl) ether and N, N'-bis (dimethylaminopropyl) urea or thiourea;

*polymeric biguanidine hydrochloride such as VANTOCIL IB ( ICI ) .

These (P) polymers generally have a molecular weight from 500 to 1,000,000 preferably from 1,000 to 40,000.

The weight ratio (dry basis) (M) / (P) in (BS) is generally from 10/90 to 90/10, preferably 15/85 to 80/20, particularly 20/80 - 40/60 and especially about 25/75.

(BS) is preferably in the form of an aqueous concentrate containing up to, say, 50, 65 or 70%, preferably up to 30 or, 35 or 40%, by weight of (M) + (P) (dry basis) . It can be prepared by simply mixing solutions of (M) and (Q) . Thus, typically, the concentrate will contain 1 to 20 or 30%, especially 1 or 5 to 10 or 15% by weight of (M) and 3 to 60%, especially 15 to 30%, by weight of (P) .

(BS) can be used as a rapid and long lasting biocide agent (additive) in a biocidal aqueous composition (BAC) , typically in an amount from 3 to 300 ppm, preferably 5 to 100 ppm, by weight (dry basis) .

(BS) and/or (BAC) can contain at least one non- ionic, amphoteric or zwitterionic surfactant. Typically the concentration of surfactant in (BAC) is

0.01% to 1% by weight while the weight ratio of surfactant/ (BS) is 0.2/1 to 8/1 preferably l/l to 5/1. Examples of suitable non-ionic surfactants include block polymers of ethylene oxide and propylene oxide, polyethoxylated sorbitan esters, sorbitan fatty esters, ethoxylated fatty esters (e.g. 1-25 oxyethylene units), ethoxylated C₈-C₂₂ alcohols (e.g. 1-12 oxyethylene units), polyethoxylated C₆-C₁₂ alkylphenols (e.g. 5-25 oxyethylene units) , alkylpolyglycosides, amine oxides (such as C₁₀-C₁₈ alkyldimethylamineoxides, C₈-C₂₂ alkoxyethyl dihydroxyethylamineoxides) .

Examples of suitable amphoteric or zwitterionic surfactants include

C₆-C₂₀ alkylamphoacetates or alkylamphodiacetates (such as cocoamphoacetates) , C₁₀-C₁₈ alkyldimethylbetaines , C₁₀-C₁₈ alkylamidopropyldimethylbetaines, C₁₀-C₁₈ alkyldimethyl sulphobetaines, C₁₀-C₁₈ alkylamidopropyldimethyl sulphobetaines .

In a preferred embodiment, (BAC) is an aqueous hard surface treatment or cleaning composition.

Other possible ingredients of the composition include:

* chelating agents such as aminocarboxylates (ethylenediaminetetraacetates, nitrilotriacetates , N,N- bis (carboxymethyl) glutamates) , citrates;

* builders such as phosphates, silicates;

* alcohols such as ethanol, isopropanol, glycols;

* Perfumes and colorants . The (BAC) compositions can be prepared simply by dilution of (BS) in water.

When other additives are present in (BAC) compositions, said additives can be added either to the (BS) system or to the dilution water or to the diluted formulation, said additives are preferably introduced in (BS) when (BS) is a solution.

Examples of microorganisms which can be controlled include: (i) Gram negative bacteria: Pseudomonas aeruginosa;

Escherichia coli ; and Proteus mirabilis .

(ii) Gram positive bacteria: Staphylococcus aureus ; and

Streptococcus faecium. (iii) Other harmful food bacteria: Salmonella typhimurium ;

Listeria monocytogenes ; Campylobacter ieiuni ; and Yersinia enterocolitica .

(iv) Yeasts: Saccharomvces cerevisiae ; and Candida albicans . (v) Fungi: Aspergillus niger ,- Fusarium solani ; and

Pencillium chrysogenum .

(vi) Algae: Chlorella saccharophilia ,- Chlorella emersonii ;

Chlorella vulgaris ; and Chlamydomonas eugametos .

The microorganisms controlled by the method of the present invention are preferably Gram negative microorganisms, especially Pseudomonas aeruginosa. Gram positive microorganisms, especially Staphylococcus aureus, and fungi e.g. Aspergillus niger. The (BAC) compositions may be applied to the hard surface by coating, spraying, dipping, brushing or wiping, for example. It can be used as surface disinfectant for floors, walls, working surfaces, equipment, furniture, instruments, in hospitals, food plants, breweries and the home (e.g. kitchens and bathrooms) . Examples of hard surfaces which can be treated include glazed or unglazed ceramics, glass, PVC, plastic laminate and other hard plastics, stainless steel or other painted or unpainted metals and painted or unpainted wood as well as flexible polymer surfaces.

The amount used will, of course, depend to some extent on the nature of the surface but, generally, total actives should amount to 1 to 1000 ppm, preferably 5 to 500 ppm and more preferably 5 to 100 ppm.

The following Examples further illustrate the present invention.

Test protocol for evaluation of (M) / (P) biocide system (BS) for biocidal activity according to AFNOR 72.150 Standard Test

Conditions

*biocide dilutions prepared in distilled water *test organism Pseudomonas aeruginosa ATCC

15442 *temperature : 20°C *contact time : 5 minutes and extended to 24 hours

*organic matter : Nil *inactivator solution : 3% Tween 80 + 2% Soya Lecithin

*result : dilution to give 5 log reduction, i.e. 99.999% kill

Procedure

1. Prepare serial dilutions of (M) / (P) biocidal system (BS) with different ratios (M) / (P) ;

2. inoculate said test dilutions with Pseudomonas aeruginosa bacterial suspension; 3. sample after 5 minutes and 24 hours, by transferring lml of test dilution to 9 mis of inactivator solution; 4. plate out inactivated test dilution on nutrient agar, incubate at 37°C for 48 hours and assess for bacterial survivors ; 5. calculate dilution which gives 5 log reduction in bacterial numbers .

When all the results had been collated, the Σ Fractional Bacterial Concentration (Σ FBC) was calculated for each particular blend.

The Fractional Bacterial Concentrations (FBC) method compares the biocidal effect of each biocide compound when used in the biocide mixture to the effect produced when each biocide compound is used alone.

FBC = concentration in the mixture/concentration when used alone Σ FBC = FBC (M) + FBC (P) Σ FBC = 1 corresponds to a normal additive effect Σ FBC = >1.0 corresponds to antagonism Σ FBC = <1.0 corresponds to synergy

Example 1 The tested biocide system (BS) consists of a blend of

- RHODAQUAT RP 50 (Rhone-Poulenc) , an aqueous solution containing 50% solids of C₁₂-C₁₄ alkyl benzyl dimethyl ammonium chloride;

- and GLOKILL PQ (Rhone-Poulenc) , an aqueous solution containing 50% solids of a polymer from epichlorhydrin and dimethylamine .

The five following dilutions were prepared

5 minutes test results

24 hours test results

An additive effect can be noted after 5 minutes (but no antagonism) and a significant synergy after 24 hours, particularly for the ratio RP50 / PQ of 1/3.

Example 2

Example 1 is repeated replacing GLOKILL PQ by GLOKILL ELC (Rhone-Poulenc) , an aqueous solution containing 50% solids of a polymer from epichlorphydrin and imidazole .

24 hours test results

Synergy after 24 hours can be noted here too

Claims

1. A rapidly active and long lasting biocide system (BS) in the form of an aqueous solution comprising water, as solvent, and at least 1% by weight of at least one watersoluble first biocidal agent which is a monoquaternary ammonium or phosphonium salt or a monoquaternary heterocyclic amine salt (M) ; and at least 3% by weight of at least one watersoluble second biocidal agent which is a polymeric quaternary ammonium salt, polymeric quaternary heterocyclic amine salt or polymeric cationic biguanide salt (P) .

2. A biocide system according to claim 1 comprising at least one nonionic, amphoteric or zwitterionic surfactant .

3. A biocide system according to claim 1 or 2 wherein the first biocidal agent is a -mono- or -di- (higher alkyl) quaternary ammonium salt.

4. A biocide system according to any one of the preceding claims wherein the first biocidal agent is a N- higher alkyl-N-aryl-N,N-di (lower alkyl) ammonium salt, a N,N-di (higher alkyl) -N,N-di (lower alkyl) ammonium salt, a N-higher alkyl-N,N, N-tri (lower alkyl) ammonium salt, a monoquaternary heterocyclic amine salt or a higher alkyl triphenyl phosphonium salt .

5 . A biocide system according to claim 4 wherein the N-higher alkyl-N-aryl-N, N-di (lower alkyl) ammonium salt is

R¹R²R³R⁴N⁺X^_ where

R¹ is optionally chloro substituted benzyl, or C₁-C₄ alkyl benzyl,

R² is C₈-C₂₄ alkyl,

R³ and R⁴ are each independently C^-C^ alkyl or C_j.-^ hydroxyalkyl, and X^" is sulfate, or methylsulfate; or the N, N-di (higher alkyl) -N, N-di (lower alkyl) ammonium salt is

R¹'R'R³'R^4,N⁺X^" where

R¹' and R²' are each independently, C₈-C₂₄ alkyl, R³' and R⁴' are each independently, C^-C^ alkyl, and X^" is halide, sulfate or methylsulfate; or the N-higher alkyl-N,N,N-tri (lower alkyl) ammonium salt is

R¹"R²"R³"R"N⁺X- where

R¹" is C₈-C₂₄ alkyl

R²'0 R³" and R⁴" are each independently C_x-C₄ alkyl, and X^" is halide, sulfate or methylsulfate; or the monoquaternary heterocyclic amine salt is laurylpyridinium chloride, cetylpyridinium chloride, C₁₂- C₁₄-alkyl-benzyl imidazolinium chloride; or the higher alkyl triphenyl phosphonium salt is myristyl triphenyl phosphonium bromide .

6. A biocide system according to any one of the preceding claims wherein the weight ratio (dry basis) (M)/(P) is 15/85 to 80/20.

7. A biocide system according to claim 6 wherein the weight ratio (dry basis (M) / (P) is 25/75.

8. A biocide system according to any one of the preceding claims, in the form of an aqueous concentrate, comprising up to 50% by weight of (M) + (P) (dry basis) .

9. A biocide system according to claim 8 comprising 5 to 10% by weight (dry basis) of (M) and 15 to 30% by weight (dry basis) of P.

10. A process for the biocidal treatment of a hard surface which process comprises applying to said surface a biocide system according to any one of the preceding claims .