EP0821720B2 - Anti-foaming composition - Google Patents

Description

The present invention relates to anti-foam compositions comprising at least one nonionic surfactant defoaming agent as well as a solubilizing agent.

Certain cleaning compositions in industrial cleaning operations such as cleaning of bottles or washing the floors can cause significant foaming. It is notably due to the presence of food soiling or glue residue present on the bottles. In order to decrease or even to prevent the formation of this foam, it is known to add to the cleaning composition one or more surfactants defoamers. These defoaming surfactants are generally of the nonionic type. However, these surfactants defoamers have limited use due to their low solubility in cleaning compositions highly concentrated alkalines, up to 50% by weight of soda or potash. In these conditions, said defoaming surfactants are not very soluble. In order to avoid having to decrease the concentration of alkaline agent to the detriment of cleaning performance, it is known to combine the defoaming surfactant with solubilizing agents, such as cumene sulfonates and xylene sulfonates or organic solvents.

Alkylpolyglycosides have also been described as solubilizers for defoaming surfactants nonionic surfactants. Alkylpolyglycosides are well-known nonionic surfactants. Their manufacturing process is for example described in patent application EP-A-0.077.167.

Patent application EP-A-0.489.777 describes anti-foam compositions comprising alkylpolyglycosides whose alkyl chain contains from 6 to 12 carbon atoms. However, to date, the only alkylpolyglycosides marketed as solubilizers non-ionic defoaming surfactants are 50-50 mixtures (by weight) of alkylpolyglycosides having, respectively, an alkyl chain with 8 carbon atoms and an alkyl chain to 10 carbon atoms. This type of solubilizing agent is marketed by the company UNION CARBIDE under the TRITON BG 10 brand.

A first object of the present invention consists of an anti-foam composition comprising a surfactant non-ionic and a particular alkylpolyglycoside having a good solubilizing power of the defoaming surfactant.

According to another aspect. the invention also relates to a cleaning composition comprising a composition defoamer based on (i) a nonionic defoaming surfactant and (ii) said particular alkylpolyglycoside.

• R représente un radical 2-éthylexyle ;
• Z est le reste d'un sucre ; et
• n est compris entre 1 et 5

The invention thus relates to an anti-foaming composition comprising at least one nonionic defoaming surfactant and at least one alkylpolyglycoside of formula (I): R (O) Z _n in which :

• R represents a 2-ethyllexyl radical;
• Z is the remainder of a sugar; and
• n is between 1 and 5

It has been established that such an alkylpolyglycoside makes it possible, surprisingly, to reinforce the anti-foaming effect. of said nonionic surfactant. There is therefore a real synergy between the latter and the compound of formula (I)

The residue Z can be chosen from the residues of the following compounds glucose, dextrose, sucrose, fructose, galactose, maltose, maltotroise, lactose, celobiose, mannose, ribose, dextran tallose, xylose and levoglucosane. Among these compounds, dextrose, fructose and maltose are preferred, glucose being very particularly preferred.

According to an advantageous aspect of the invention, n is between 1.1 and 2.

dans laquelle :

• R₁ est un radical alkyle linéaire ou ramifié, comprenant 6 à 14 atomes de carbone, de préférence 8 à 10 atomes de carbone ;
• a, b et c, identiques ou différents, sont des entiers compris entre 1 et 10.

The defoaming nonionic surfactants according to the invention are chosen from

in which :

• R ₁ is a linear or branched alkyl radical, comprising 6 to 14 carbon atoms, preferably 8 to 10 carbon atoms;
• a, b and c, identical or different, are integers between 1 and 10.

An anti-foaming composition according to the invention can be in concentrated or diluted form, ready to employment

When it is in concentrated form, it can comprise from 10 to 50% by weight of at least one compound of formula (I) and from 20% to 70% by weight of at least one nonionic defoaming surfactant.

When it is in diluted form it may comprise from 0.004% to 10% by weight of at least one compound of formula (I) and from 0.004% to 20% by weight of at least one nonionic defoaming surfactant.

This defoaming composition generally comprises a compound of formula (I) and a nonionic surfactant defoaming in a weight ratio between 1/10 and 10/1, preferably between 1/5 and 5/1.

According to another aspect of the invention, it relates to the use of an anti-foaming composition such as defined above as an anti-foaming agent.

According to yet another aspect of the invention, it relates to cleaning compositions comprising an anti-foaming composition as described above. This cleaning composition according to the invention comprises usually 2 to 50% by weight of one or more alkaline agents. The alkaline agent used in these compositions is usually soda or potash. The cleaning compositions according to the invention can contain a content such as the anti-foaming composition that the concentration of nonionic defoaming surfactant in said cleaning composition is between 0.001 and 2% by weight.

The following examples are intended to illustrate the present invention.

Example 1

(i) on a préparé différentes solutions comprenant (% en poids) :

• tensioactif démoussant⁽¹⁾:   0.006
• APG :   0.006
• base alcaline à 10 %⁽²⁾   3
• lait en poudre Régilait® en dispersion à 10 %:   7,5
• eau désionisée.   q.s.p. 100
• ⁽¹⁾ : alcool de formule (II) précités, commercialisé par la société S.E.P.P.I.C., sous la marque SIMULSOL™ NW 342
• ⁽²⁾ : base alcaline comprenant (% en poids) : tripolyphosphate de sodium : 3,5 métasilicate de sodium 5H₂O : 4,2 carbonate de sodium anhydre : 2,3 eau désionisée. q.s.p. 100

(ii) On a soumis la solution à une agitation rotative, pendant trois minutes et on a mesuré la hauteur de mousse (en mm) formée après un repos de 5 secondes. L'agitation était telle qu'une solution similaire, mais ne comprenant ni tensioactif démoussant, ni APG, formait une mousse d'une hauteur de 30 mm.

We tested the defoaming power of different alkylpolyglucosides (APG) of variable length of alkyl chain according to the following procedure:

(i) various solutions were prepared comprising (% by weight):

• defoaming surfactant ⁽¹⁾ : 0.006
• APG: 0.006
• 10% alkaline base ⁽²⁾ 3
• Régilait® milk powder 10% dispersion: 7.5
• deionized water. qs 100
• ⁽¹⁾ : alcohol of formula (II) above, sold by the company SEPPIC, under the brand SIMULSOL ™ NW 342
• ⁽²⁾ : alkaline base comprising (% by weight): sodium tripolyphosphate: 3.5 sodium metasilicate 5H ₂ O: 4.2 anhydrous sodium carbonate: 2.3 deionized water. qs 100

(ii) The solution was subjected to rotary stirring for three minutes and the height of foam (in mm) formed after standing for 5 seconds was measured. The agitation was such that a similar solution, but comprising neither defoaming surfactant nor APG, formed a foam with a height of 30 mm.

The results obtained are shown in Table I. APG (alkyl chain) Foam height (mm) n-hexyl 10.5 n-octyl 12.5 2-ethylhexyl 10 n-octyl + n-decyl (50/50 mixture by weight) 15.5

These results show that compositions according to the invention comprising an APG in which the alkyl chain is a 2-ethylhexyl radical, makes it possible to obtain a defoaming power greater than that obtained with a 50/50 mixture of C ₈ - APG - C ₁₀ or with APGs comprising an n-octyl or n-hexyl radical.

It can be noted that a composition not comprising APG but only the defoaming surfactant produces a foam height of 14 mm.

Example 2

• on a préparé 100 g d'une solution comprenant (en g) :
  • SIMULSOL™ NW 342 :   0,1
  • NaOH :   5
  • H₂O.   q.s.p: 100
• la solution obtenue est biphasique et trouble ;
• on verse dans cette solution biphasique différents agents solubilisants consistant en des APG à différentes longueurs de chaíne alkyle ou des agents solubilisants classiques, à savoir le xylèno sulfonate d'ammonium et le cumène sulfonate d'ammonium ;
• on interrompt l'introduction de l'agent stabilisant dès que la solution biphasique est devenue parfaitement limpide et monophasique ;
• le poids en agent solubilisant requis pour obtenir une solution limpide représente son pouvoir solubilisant.

The solubilizing power of different APGs was tested against SIMULSOL NW 342 according to the following procedure:

• 100 g of a solution were prepared comprising (in g):
  • SIMULSOL ™ NW 342: 0.1
  • NaOH: 5
  • H ₂ O. qs: 100
• the solution obtained is biphasic and cloudy;
• is poured into this two-phase solution different solubilizing agents consisting of APGs at different lengths of alkyl chain or conventional solubilizing agents, namely xylene ammonium sulfonate and cumene ammonium sulfonate;
• the introduction of the stabilizing agent is interrupted as soon as the biphasic solution has become perfectly clear and monophasic;
• the weight of solubilizing agent required to obtain a clear solution represents its solubilizing power.

The results obtained are shown in Table II below: Solubilizing agent Weight (in g) of solubilizing agent to obtain a clear solution N-hexyl chain APG 3.5 2-ethylhexyl APG 0.96 xylene ammonium sulfonate 1.6 cumene ammonium sullonate 3

These results show that an alkylpolyglucoside comprising an n-hexyl chain has a solubilizing power. weak and in any case lower than that of a conventional solubilizing agent of the cumene and xylene type. On the contrary, a 2-ethylhexyl chain alkylpolyglucoside has good solubilizing power.

Claims (8)

1. Anti-foaming composition comprising at least one nonionic defoaming surfactant and at least one alkylpolyglycoside of formula (I): R(O)Z_n    in which:

   R represents a 2-ethylhexyl radical,

   Z is a sugar residue, and

   n is between 1 and 5,

   characterized in that the nonionic defoaming surfactant is a compound of formula (II):

   

      in which:

   R₁ is a linear or branched alkyl radical comprising 6 to 14 carbon atoms, preferably 8 to 10 carbon atoms;

   a, b and c, which may be identical or different, are integers between 1 and 10.
2. Composition according to Claim 1, characterized in that Z is a glucose residue.
3. Composition according to either of Claims 1 and 2, characterized in that n is between 1.1 and 2.
4. Composition according to one of Claims 1 to 3, characterized in that the weight ratio between the compound of formula (I) and the nonionic defoaming surfactant is between 1/10 and 10/1, preferably between 1/5 and 5/1.
5. Use of a composition according to one of Claims 1 to 4 as an anti-foaming agent.
6. A cleaning composition, characterized in that it comprises an anti-foaming composition according to one of Claims 1 to 4.
7. A cleaning composition according to Claim 6, characterized in that it comprises from 2 to 50% by weight of an alkaline agent.
8. A cleaning composition according to Claim 6 or 7, characterized in that it comprises from 0.001% to 2% by weight of a nonionic defoaming surfactant.