GB2391478A

GB2391478A - Phenolic disinfectants

Info

Publication number: GB2391478A
Application number: GB0218269A
Authority: GB
Inventors: Carol Christine Bilverstone; Nigel Frederick Cooper; Sharron Iles
Original assignee: Jeyes Group Ltd
Current assignee: Jeyes Group Ltd
Priority date: 2002-08-06
Filing date: 2002-08-06
Publication date: 2004-02-11
Also published as: GB0218269D0

Abstract

A disinfectant solution comprises a phenolic active ingredient, an organic solvent for solubilising the active ingredient, and an anionic surfactant or a soap. The solution has a pH in the range 8 to 9, and a co-solvent is provided to form a stable emulsion on dilution with water. The solution preferably comprises dichlorophen, castor soap, ethylene glycol monobutyl ether, alcohol ethoxylate, a dye and perfume.

Description

M&C Folio: GBP86011 2391478 Disinfectants The present invention relates to

disinfectants, and in particular to disinfectants incorporating a high concentration of a phenol analogue as the active ingredient. Such solutions are sold in concentrated form, and are often diluted with water before use, typically 1 part in I O parts water to 1 part in 1000 parts of water. As a biocide or herbicide they may be poured down drains in the concentrated form, or diluted with water for spraying, watering, washing down and the like. Low concentration formulations may also be prepared for medical use (e.g. DETTOL, registered trade mark). A difficulty with such solutions is that to obtain a concentrated form which is stable on dilution, i.e., the active ingredient remains solubilised or homogeneously dispersed as an emulsion for a useful period of time, the solution is at high pH, typically pH 13, to provide the sodium salt of the active ingredient. Such a high pH product is severely irritating to the eyes and so can be prohibited for amateur use.

Thus it is desirable to provide a phenolic based herbicide or biocide having a relatively low pH and so safer for use, and in which the active ingredient will remain dispersed on aqueous dilution.

The invention provides a disinfectant solution comprising a phenolic active ingredient, an organic co-solvent for solubilising the active ingredient, an anionic surfactart or a soap, and a co-solvent for stabilizing the emulsion on dilution with water.

The phenolic active ingredient is present in an amount of from 1 to 50% by weight of the total composition, more preferably at least 4 or 5% and more preferably at

least 10% by weight. An amount of from 10% to 30% by weight is particularly preferred and more preferably 10% to 20%.

The organic solvent is preferably present in an amount of from 1% to 50% by weight of the total composition, more preferably from about 15% to about 30%. The organic solvent is preferably present in an amount of about 1 to 1.5 times the amount of the phenolic active ingredient.

The soap is an aqueous solution and provides the major balance of the composition and may be present in an amount of from about 50% to 90% by weight, preferably 50% to about 75% by weight.

The co-solvent is an agent to aid dispersion of the active ingredient on dilution of the composition with water and to stabilise the resulting emulsion. The preferred co-solvent is a surfactant, preferably a nonionic surfactant such as an alcohol ethoxylate, or other antiflocculant such as a polyacrylate, but other dispersants such as lecithin may also be suitable. Such suitable co-solvents may be found by trial and error.

The preferred phenolic active ingredient, a phenol analogue, is dichlorophen (4,4 dichloro 2,2 methylenediphenol) but other phenol analogues, that is compounds having a phenol grouping with a biocidal or herbicidal action, may be used, such as cresols, xylenols, resorcinols, and napthols.

Typically the molecular weight will be less than about 250. Preferred phenol analogues include ortho phenol phenol, chloro cresols, chlorophen, dichloro mete xylenol and pare chloro metaxylenol (4 chloro 3,5 dimethyl phenol).

The preferred solvent is a polar organic solvent which is miscible with water.

Alcohols, such as ethanol, may be used but a glycol is preferred and in particular a glycol ether, particularly ethylene glycol monobutyl ether.

The soap is in aqueous solution or dispersion. Castor soap is particularly preferred and is typically available as 30 or 35% active (i. e. formulated from 30 or 35%

by weight castor oil, about 4% sodium hydroxide and the balance water). Other soaps which may be used include palm kernel, tallow or coconut soaps. Surfactants, such as long chain fatty acids, particularly the sodium salts of saturated C'2-Ci4 surfactants may also be suitable although the soaps incorporating a glycerol by-product are preferred.

The pH of the composition is preferably less than pH 11, and more preferably from about pH 7.5 to pH 10, more particularly about pH 8 to pH 9.

On dilution with water, for example for spraying plants, the pH will remain fairly constant.

It is import that the active ingredient, the phenol analogue, remain dispersed or in solution, i.e. giving a stable emulsion, for a reasonable period of time after dilution, commensurate with the intended use. Preferably the emulsion will be stable for about 8 hours, more preferably for at least 24 hours, and more preferably for about 48 hours. This provides sufficient time for the diluted composition to be used.

The composition may include dyes and perfumes as well known in the art.

A composition according to the following fonnulation was prepared: % by weight Dichlorophen 1 0 (4,4 dichloro 2,2 methylene diphenol) Castor Soap (30% active) 72.5 Butyl Oxitol (T.M.) 15 (ethylene gIycol monobutyl ether) Synperonic 91161G (T.M.) 2 (alcohol ethoxylate)

Dye, Perfume 0.5 The solution had long term stability when stored at ambient temperatures.

The solution was diluted with water at concentrations of 1 part solution: 10 parts water, 100 parts water and 1000 parts water and formed a whiteish dispersion which did not flocculate or precipitate out for a period of at least 24 hours.

Claims

CLAIMS:

1. A disinfectant solution comprising a phenolic active ingredient, an organic solvent for solubilising the active ingredient, and an anionic surfactant or a soap, wherein a co-solvent is provided to stabilize the emulsion on dilution with water.

2. A disinfectant solution as claimed in claim 1, wherein the active ingredient is present in an amount of from 1 to 50% by weight.

3. A disinfectant solution as claimed in claim 2, wherein the active ingredient is present in an amount of at least 5% by weight.

4. A disinfectant solution as claimed in claim 3, wherein the active ingredient is present in an amount of at least 10% by weight.

5. A disinfectant solution as claimed in claim 4, having from 10% to 30% by weight of the active ingredient.

6. A disinfectant solution as claimed in any one of claims I to 5, wherein the phenolic active ingredient is a phenol analogue having a molecular weight of less than about 250.

7. A disinfectant solution as claimed in claim 6, wherein the phenolic active ingredient is selected from the group comprising phenols, cresols, xylenols, resorcinols and napthols.

8. A disinfectant solution as claimed in claim 7, wherein the active ingredient is selected from 4,4 dichloro,2 methylenediphenol; orthophenol phenol; chlorophen; dichloro mete Tylenol and pare chloro mete Tylenol.

9. A disinfectant solution as claimed in any one of claims 1 to 8, wherein the solvent is a polar organic solvent.

10. A disinfectant solution as claimed in claim 9, wherein the solvent is a glycol.

1 1. A disinfectant solution as claimed in claim 10, wherein the solvent is a glycol ether.

12. A disinfectant solution as claimed in claim I 1, wherein the solvent is ethylene glycol monobutyl ether.

13. A disinfectant solution, wherein the solvent is present in an amount of from I to 3 times the amount, in % by weight, of the active ingredient.

14. A disinfectant solution as claimed in claim 13, wherein the organic solvent is present in an amount of from 1 to 1.S times the amount of the active ingredient.

1 S. A disinfectant solution as claimed in any one of claims 1 to 14, wherein the soap is an aqueous soap solution and the solution comprises from SO to 90% by weight of the composition, and preferably 60 to 80% by weight.

16. A disinfectant solution as claimed in any one of claims I to 15, wherein the soap or anionic surfactant is a long chain fatty acid salt.

17. A disinfectant as claimed in any one of claim 1 to 15, wherein a soap is used and is selected from castor, palm kernel, tallow and coconut soaps.

18. A disinfectant solution as claimed in any one of claims 1 to 17, wherein the co-

solvent is present in an amount of from 0.1 to 5 % by weight of the composition.

19. A disinfectant composition as claimed in claim 18, wherein the cosolvent is present in an amount of from 1 to 3 % by weight.

20. A disinfectant composition as claimed in any one of claims 1 to 19, wherein the co-solvent is a non-ionic surfactant.

21. A disinfectant composition as claimed in any one of claims 1 to 19, wherein the co-solvent is an anti-floccueant.

22. A disinfectant composition as claimed in any one of claims I to 19, wherein the co-solvent is a polyacrylate

23. A disinfectant solution as claimed in any one of claims 1 to 22, having a pH from pH8topH9.

24. A disinfectant solution as claimed in any one of claims 1 to 23, which provides a dispersion which is stable for about 8 hours or more on dilution with greater than 1 part solution to 100 parts water.

25. A disinfectant solution substantially as hereinbefore described with reference to the examples