1. Field of the Invention
A subject matter of the present invention is a cleaning and disinfecting composition of particular use in the cleaning and disinfecting of pipes and vessels of plants in the food industry, in particular the brewing industry, dairy industry, and the like.
2. Description of the Related Art
Compositions for cleaning and disinfecting plants in the farm produce industries are mainly used in systems known as xe2x80x9ccleaning in placexe2x80x9d (CIP) systems, according to which the plant is cleaned and disinfected without being disassembled, the disinfecting cleaning composition being circulated in the plant by pumping and/or applied by spraying (by means of permanently installed sprayers), so as to reach all parts of the plant to be treated.
In order to be applicable in a truly satisfactory manner in the food industry and more particularly in the brewing industry, such a disinfecting composition must combine several properties and must meet several requirements which it is difficult to satisfy simultaneously.
A solution for use prepared by dilution of such a composition must in particular have a satisfactory microbiocidal action, both with regard to gram+ and gramxe2x88x92 bacteria and with regard to yeasts, such as Saccharomyces, Candida, and the like. A satisfactory microbiocidal effect is considered to have been obtained when the initial population of microorganisms is reduced by a factor of 105 in less than 20 minutes at 3xc2x0 C.
Such a solution for use must also be non-foaming or, in any case, exhibit very little foaming. This is because the formation of foam can result in cavitation of the pumps of the CIP system, causing non-circulation of the disinfecting solution and possibly destroying the pumps. In addition, the formation, even modest, of foam can result in difficulties during rinsing.
Such a solution for use must also have a good cleaning and optionally descaling power and be fully rinsable, that is to say without risk of specific adsorption on the surfaces of the materials commonly encountered in plants in the food industry.
The concentrated composition must be stable and homogeneous.
The solution for use prepared by dilution of this concentrated composition must also itself be homogeneous and sufficiently stable to allow it be recovered. This is because the solutions for use used in a CIP system are recovered after use and collected in storage tanks in order to be reused during a subsequent cleaning and disinfection operation on the plant.
Before a fresh use of a recovered solution for use, the concentration of this solution should generally be readjusted by the addition of a certain amount of the concentrated composition. It is consequently important for the concentration of the solution for use to be able to be easily measured continuously. When the solution for use comprises a constituent such as a strong acid, the concentration of active constituents in the solution is very easily measured by measuring the electrical conductivity of the solution, since this conductivity is approximately proportional to the concentration of strong acid, which concentration is proportional to that of the other active constituents of the solution for use.
Numerous compositions for cleaning and/or disinfecting plants in the agricultural and food industries have already been provided.
EP-A-0,147,102 discloses an antimicrobial composition comprising an inorganic acid and/or an organic acid, an xcex1-halogenated acetic acid and a linear or branched aliphatic fatty acid.
An antimicrobial composition which essentially comprises an aliphatic alcohol having from 6 to 12 carbon atoms and an aliphatic acid having from 2 to 6 carbon atoms, which acid is substituted at the xcex1-position by a chloro, iodo, cyano, nitro, amino, imino, thiohydroxyl or hydroxyl radical, is known from EP-A-0,208,403. This composition can also comprise an organic or inorganic acid.
EP-A-0,524,075 discloses a disinfecting acid composition based on phosphoric acid and optionally on hydroxyacetic acid comprising a specific nonionic surface-active agent and an anionic hydrotropic agent of the arylsulfonate or alkylsulfonate type.
A dilutable disinfecting cleaning composition comprising a fatty acid, a hydrotropic agent of the type of surface-active sulfonates, a strong acid and a stabilizing agent consisting of propionic acid, butyric acid, valeric acid or a mixture of these acids, is known from WO 94/10837.
Disinfecting and cleaning compositions for the food industry are known from the document EP-A-0,245,928, these compositions comprising a monocarboxylic or dicarboxylic acid, a solubilizing agent, a diluent and an acid or a mixture of acids, in order to ensure a pH of less than 5. As specified in the document EP-B-0,245,928, the solubilizing agent must be an agent of the alkylated N,N-dimethylamine oxide type with 8 to 10 carbon atoms in the alkyl part in order for the composition to be stable and not very foaming.
It has now been found that compositions not comprising this solubilizing agent are stable and not very foaming and have an excellent effectiveness in combating bacteria and yeast. Furthermore, the compositions according to the invention can be easily discharged from the vessels and pipes by rinsing, so that any risk of detrimental change in the taste or flavor of the foodstuff by the presence of traces of compositions according to the invention can be avoided. The compositions according to the invention are therefore fungicidal and bactericidal compositions of low toxicity.
The disinfecting composition according to the invention, which is provided either in concentrated form or in dilute form, is a liquid composition comprising:
(a) a monocarboxylic acid of formula
Rxe2x80x94COOH
xe2x80x83with R a saturated or unsaturated, straight- or branched-chain alkyl radical comprising from 6 to 12 carbon atoms (preferably from 8 to 10 carbon atoms), or a mixture of such carboxylic acids;
(b) a strong inorganic acid,
(c) an organic acid of formula:
Rxe2x80x2CH2xe2x80x94CO2H
xe2x80x83with Rxe2x80x2: H or OH,
xe2x80x83or a mixture of such organic acids;
(d) one or more anionic surfactants;
(e) a solubilizing agent consisting of a compound of formula:
Rxe2x80x3O(CH2CH2O)xxe2x80x94H
xe2x80x83in which
Rxe2x80x3 represents a C2 to C6 alkyl radical,
x represents an integer from 1 to 3, or a mixture of such compounds;
(f) water.
The composition according to the invention is a bactericidal and fungicidal composition.
According to one embodiment of the concentrated composition, it comprises:
(a) from 0.25 to 20% by weight of a monocarboxylic acid of formula:
Rxe2x80x94COOH
xe2x80x83with R a saturated or unsaturated, straight- or branched-chain alkyl radical comprising from 6 to 12 carbon atoms, or of a mixture of such carboxylic acids;
(b) from 20 to 40% by weight of a strong inorganic acid;
(c) from 0.25 to 7% by weight of an organic acid of formula:
Rxe2x80x2CH2xe2x80x94CO2H
xe2x80x83with Rxe2x80x2: H or OH,
xe2x80x83or from 0.5 to 12% by weight of a mixture of such organic acids;
(d) from 5 to 20% by weight of anionic surfactant(s), and
(e) from 1 to 10% by weight of a solubilizing agent consisting of a compound of formula:
Rxe2x80x3O(CH2CH2O)xxe2x80x94H
xe2x80x83in which
Rxe2x80x3 represents a C3 to C5 alkyl radical,
x represents an integer from 1 to 3, or a mixture of such compounds.
In a particularly advantageous way, the composition comprises:
(a) from 0.5 to 15% by weight of a monocarboxylic acid of formula:
Rxe2x80x94COOH
xe2x80x83with R a saturated or unsaturated, straight- or branched-chain alkyl radical comprising from 6 to 12 carbon atoms, or of a mixture of such carboxylic acids;
(b) from 25 to 35% by weight of a strong inorganic acid;
(c) from 2 to 5% by weight of an organic acid of formula:
Rxe2x80x2CH2xe2x80x94CO2H
xe2x80x83with Rxe2x80x2: H or OH,
xe2x80x83or from 5 to 10% by weight of a mixture of such organic acids;
(d) from 7 to 13% by weight of anionic surfactant(s), and
(e) from 3 to 7% by weight of a solubilizing agent consisting of a compound of formula:
Rxe2x80x3O(CH2CH2O)xxe2x80x94H
xe2x80x83in which
Rxe2x80x3 represents a C2 to C6 alkyl radical,
x represents an integer from 1 to 3, or a mixture of such compounds.
The strong inorganic acid present in the composition is preferably chosen from sulfuric acid, phosphoric acid and their mixtures.
Use is advantageously made, in the formulation according to the invention, of glycolic acid as organic acid of formula Rxe2x80x2CH2xe2x80x94CO2H or of a mixture of glycolic acid and acetic acid as mixture of organic acids of formula Rxe2x80x2CH2xe2x80x94CO2H. As advantageous example, the mixture of said organic acids contains from 30 to 70% by weight of glycolic acid and from 70 to 30% by weight of acetic acid.
According to a specific embodiment of the invention, the solubilizing agent is chosen from:
the compound of formula CH2(CH2)3xe2x80x94Oxe2x80x94CH2CH2OH (2-butoxyethanol or xe2x80x9cbutyl glycolxe2x80x9d)
the compound of formula CH2(CH2)3xe2x80x94Oxe2x80x94(CH2CH2O)2H (2-(2-butoxyethoxy)ethanol or xe2x80x9cbutyl diglycolxe2x80x9d).
In addition, the composition according to the invention advantageously comprises from 0.1 to 1.0% by weight of a nonionic surface-active agent of general formula:
Rxe2x80x2xe2x80x3O(CH2CH2O)yH
in which
Rxe2x80x2xe2x80x3 is a saturated C16 to C18 alkyl radical, and
y is an integer between 8 and 40, or a mixture of such nonionic surface-active agents.
This nonionic surface-active agent can consist in particular of a compound of formula:
Rxe2x80x2xe2x80x3O(CH2CH2O)yH
in which
Rxe2x80x2xe2x80x3 is a saturated C16 to C18 alkyl radical, and
y is equal to approximately 11.
Such a nonionic surface-active agent is sold, for example, by the firm BASF under the name Lutensol AT 11(copyright).
The composition advantageously comprises from 0.3 to 0.4% by weight of such a nonionic surface-active agent.
The pH of the composition is advantageously less than 5.
According to a specific embodiment, the strong inorganic acid/organic acid(s) of formula Rxe2x80x2CH2xe2x80x94CO2H ratio by weight is between 2/1 and 5/1.
The organic acid(s) of formula Rxe2x80x2CH2CO2H/monocarboxylic acid(s) of formula Rxe2x80x94COOH ratio by weight is advantageously between 3/1 and 10/1.
The organic acid(s) of formula Rxe2x80x2CH2xe2x80x94CO2H/solubilizing agent of formula Rxe2x80x3Oxe2x80x94(CH2CH2O)xxe2x80x94H ratio by weight is preferably between 3/1 and 1/1.
Use is advantageously made, as anionic surfactant, of a mixture of anionic surfactants, for example a mixture of a sulfonate surfactant, such as an alkylbenzenesulfonate with 8 to 16 carbon atoms, for example cumenesulfonate, and of a sulfonate from the family of the ether carboxylic acids, for example a mixture of ether carboxylic acids comprising from 15 to 25 carbon atoms and corresponding to the following general formula:
Rxe2x80x3xe2x80x3(OC2H4)nOCH2COOH
with Rxe2x80x3xe2x80x3 an alkyl group with 4 to 12 carbon atoms.
The sulfonate surfactant is advantageously chosen from alkylsulfonates with 8 to 16 carbon atoms and the mixtures of these. When use is made of a mixture of sulfonate surfactant and of ether carboxylic acid surfactant, use is made of a mixture containing, for example, from 20 to 80% by weight of sulfonate surfactant and from 80 to 20% by weight of ether carboxylic acid surfactant. However, the mixture advantageously comprises more than 50% by weight of sulfonate surfactant.
Another subject matter of the invention is the use of a composition according to the invention as fungicidal composition, in particular fungicidal and bactericidal composition.
A further subject matter of the invention is a process for disinfecting a plant (pipework), vessels, and the like), in which process a composition according to the invention, preferably in dilute form, is brought into contact with the plant.
The concentrated composition is advantageously diluted so that the solution, after dilution, has a content of strong inorganic acid of less than 0.4% and at pH of less than 4, preferably of less than 3.
Disinfecting is advantageously carried out at a temperature of between 0 and 25xc2x0 C.