Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – Specific organic component
Reexamination Certificate
2001-04-09
2002-10-08
Boyer, Charles (Department: 1751)
Cleaning compositions for solid surfaces, auxiliary compositions
Cleaning compositions or processes of preparing
Specific organic component
C510S237000, C510S238000, C510S362000, C510S384000, C510S391000, C510S421000, C510S356000, C510S329000, C510S289000
Reexamination Certificate
active
06462014
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to cleaning applications that require low foam or non-foam cleaning formulations such as in automatic dishwashers, Cleaning in Place (CIP), automatic floor scrubbers, enclosed parts cleaning and the like. Any foam that is generated in these systems should be unstable and break down rapidly to prevent accumulation of foam during the process.
BACKGROUND OF THE INVENTION
Typical hard surface cleaning formulations consist of a nonionic surfactant or solvent component, an electrolyte component (chelates or builders) and a hydrotropic co-surfactant (amphoteric, anionic or cationic surfactants). Quaternary ammonium compounds can function as the hydrotropic co-surfactants.
In the cleaning industry there are several specialized categories of cleaning where foaming can be very detrimental to the application. Examples of such formulations include Cleaning In Place formulations, automatic floor scrubber formulations, automatic dishwasher formulations, re-circulatory metal parts cleaning and the like. These types of formulations demand low, fast breaking foams to avoid overflow, product loss, pump cavitation, and streaks/films on treated surfaces after drying. If the cleaning formulation shows any tendency to foam then the high turbulence caused by either brushes or water sprays will result in foam.
In order to address the foaming issues, formulators often add oils or silicon defoamers to reduce or eliminate foam. Often these additives leave films and deposits on the surface, resulting in a poorly cleaned surface. Secondly at high concentrations of alkaline salts, such as in aqueous concentrates in which typically the cleaning compositions are supplied to the end user, these additives are not soluble.
Formulators also use low foam or defoaming nonionic surfactants in these cleaning formulations to minimize foam. Examples include EO/PO block copolymers, branched alcohol ethoxylates, capped alcohol ethoxylates and the like. However, the addition of hydrotropes or hydrotropic co-surfactants that couple the electrolytic component and the low foam/defoam nonionic component together can result in foam stabilization, foam addition or foam boosting negating the effect of the low foaming or defoaming nonionic. This has resulted in many formulators avoiding the use of hydrotropes in their cleaning formulations. Additionally, these cleaning formulations have the lowest foam profile when the cleaning is done at temperatures above the formulations cloud points which results in cleaning solutions that are unstable and inefficient. Also, these formulations tend to have depletion problems especially in enclosed re-circulator systems. This requires that the nonionic surfactant be replenished in order to prevent flash foam occurrence.
The present invention has solved the deficiencies of the prior art by providing low foaming and/or defoaming formulations, which comprise an alkoxylated quaternary ammonium compound and at least one nonionic compound of a specific structure.
SUMMARY OF THE INVENTION
The present invention generally relates to low foaming and/or defoaming cleaning formulations which comprise a synergistic combination of one or more hydrotropic alkoxylated quaternary ammonium compounds and at least one nonionic surfactant based on branched alcohols. The nonionic surfactant may be selected from structures having 3 to 12 moles of ethoxylation, but preferably have an average of 3-6 moles of ethoxylation with either narrow or broad range distribution.
DETAILED DESCRIPTION OF THE INVENTION
The present invention generally relates to low foaming and/or defoaming cleaning formulations which comprise a synergistic combination of one or more hydrotropic alkoxylated quaternary ammonium compounds and at least one nonionic surfactant based on branched alcohols.
The hydrotropic alkoxylated quaternary ammonium compound is preferably selected from the group of compounds represented by General Formula I, below.
R
1
R
2
R
3
R
4
N
+
X
−
(I)
wherein R
1
is a linear or branched, saturated or unsaturated C
6
-C
22
alkyl group;
R
2
is C
1
-C
6
alkyl group or R
1
;
R
3
and R
4
are C
2
-C
4
random or block polyoxyalkylene groups; and
X
−
is an anion, preferably chloride, methyl sulfate, bromide, iodide, acetate, carbonate, and the like.
Preferred compounds within the scope of general Formula I are represented by General Formula II, below.
wherein R
1
, R
2
, and X
−
are as defined above;
each R
5
is independently at each occurrence C
1
-C
2
alkyl or H, provided that R
5
is a C
1
-C
2
alkyl in at least one occurrence; and
A and B are integers greater than or equal to 1 wherein A+B is 2-50.
Most preferred hydrotropic quaternary ammonium compounds within the scope of the present invention are as shown below where R=linear or branched, saturated or unsaturated C
12
-C
22
alkyl, n+n′=0-10, m+m′=1-20, y+y′=0-20, and X
−
is an anion, preferably chloride or methyl sulfate, provided that when n+n′=0, y+y′ is at least 1.
An especially preferred hydrotropic quaternary ammonium compound is Berol CHLF available from Akzo Nobel Surface Chemistry LLC, Chicago, Ill., USA:
where R is tallow alkyl, n+n′=2, m+m′=12, y+y′=5 and X is methyl sulfate.
The quaternary ammonium compound described in this invention may be prepared by quaternization of the starting amino compound described below using known methods such as that described in U.S. Pat. No. 5,885,932 which is incorporated herein by reference. The fourth substituent added to the amino nitrogen by quaternization is preferably a group selected from alkyl, or alkenyl group having 1-4 carbons. Any suitable anion can be employed. Preferred anions include, but are not limited to, a member selected from the group consisting essentially of methyl sulphate, carbonate, chloride, fluoride, bromide, acetate and the like.
The starting amino group can be prepared by reacting an amine selected from the group consisting of R
1
—NH
2
and R
1
R
2
NH wherein R
1
and R
2
as in structure (I); with at least one propylene oxide and at least one alkylene oxide. Preferred alkylene oxides include but are not limited to ethylene oxide, propylene oxide, isobutylene oxide, butylene oxide and mixtures thereof. The compounds of the present invention are made in such a way as to introduce varying numbers of alkylene oxide units onto the amino nitrogen. The additional alkylene oxide groups may be all the same, such as, for example, one or more ethylene oxide units, or the groups may be different to form, for example, block copolymer chains of ethylene oxide and propylene oxide units, random copolymer chains consisting of several units of each of two or more different alkylene oxides, or alternating units of two or more alkylene oxides. Any conceivable combination of alkylene oxide units up to 50 units long may be employed at each available location on the amino nitrogen. For example, the amino nitrogen may contain two different alkylene oxide chains attached thereto or two chains that are the same.
In a preferred embodiment, block copolymer chains of ethylene oxide and one or more of propylene oxide or butylene oxide are employed. Preferably, the molar weight of the compounds used in the present invention is less than 8000 though higher molecular weight compounds can be employed. Typical compounds suitable for use in the present invention include, but are not limited to, bis(hydroxyethyl)methyltallow alkyl, ethoxylated, propoxylated, methyl sulphate; cocobis(2-hydroxyalkyl)methylammonium chloride; polyoxyalkylene (15) cocomethylammonium chloride; oleylbis(2-hydroxyalkyl)methyl ammonium chloride; polyoxyalkylene (15) stearylmethyl ammonium chloride; N,N-bis(2-hydroxyalkyl)-N-methyloctadecanaminium chloride; N-tallowalkyl-N,N′-dimethyl-N-N′-polyalkyleneglycol-propylenebis-ammonium-bis methylsulphate; polyoxyalkylene (3) tallow propylenedimonium dimethylsu
Franklin Ralph
Johnson Andress K.
Akzo Nobel N.V.
Boyer Charles
Mancini Ralph J.
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