EP0340704B1 - Aqueous acid detergent compositions - Google Patents

Abstract

The compositions contain as essential components (a) 1 to 20% by weight of at least one non-ionic surfactant based on alkoxylated fatty alcohols, fatty acids, fatty amines, fatty acid amides or alkanesulphonamides, (b) 0.1 to 15% by weight of at least one polyether polyol which is obtainable by reaction of 2 to 6-hydric alcohols, which have 2 to 10 C atoms, with alkylene oxides containing 2 to 4 C atoms, and reaction of these reaction products with 1,2-alkylene oxides, alkyl or alkenyl glycidyl ethers containing 8 to 30 C atoms and (c) 1 to 40% by weight of at least one acid.

Description

Aqueous acidic cleaner formulations are known. They contain tensides and acids as essential components. The known acidic technical cleaners are used, for example, in dairies to remove deposits of lactic acid. They are also used to clean pipelines in which deposits of calcium and magnesium carbonates have formed. In order to extend the exposure time of these technical cleaning systems when cleaning hard surfaces and thus to ensure optimal cleaning performance, the cleaning agent formulations must have a minimum viscosity to prevent the formulation from running off too quickly from the surface to be cleaned. The viscosity of the known cleaner formulations is adjusted by using mixtures of different alkylphenol ethoxylates with different degrees of ethoxylation. Due to the ecologically necessary replacement of the alkylphenol ethoxylates, nonionic surfactants based on alkoxylated fatty alcohols, fatty acids, fatty amines, fatty acid amides or alkanesulfonamides are now used. However, the viscosity of such aqueous acidic cleaning formulations is not yet sufficient.

The present invention has for its object to provide aqueous acidic cleaner formulations which have an increased viscosity compared to the known acidic technical cleaners. The cleaner formulations should also be stable in storage.

• (a) 1 bis 20 Gew.-% mindestens eines nichtionischen Tensids auf der Basis von alkoxylierten Fettalkoholen, Fettsäuren, Fettaminen, Fettsäureamiden oder Alkansulfonamiden,
• (b) 0,1 bis 15 Gew.-% mindestens eines Polyetherpolyols, das erhältlich ist durch Umsetzung von 2- bis 6-wertigen Alkoholen, die 2 bis 10 C-Atome aufweisen, mit 2 bis 4 C-Atome enthaltenden Alkylenoxiden und Reaktion dieser Umsetzungsprodukte mit 8 bis 30 C-Atome enthaltenden 1,2-Alkylenoxiden, Alkyl- oder Alkenylglycidethern und
• (c) 1 bis 40 Gew.-% mindestens einer Säure.

The object is achieved according to the invention with aqueous acidic cleaning formulations which contain surfactants and which are characterized by a content of - in each case based on the weight of the entire formulation -

• (a) 1 to 20% by weight of at least one nonionic surfactant based on alkoxylated fatty alcohols, fatty acids, fatty amines, fatty acid amides or alkanesulfonamides,
• (b) 0.1 to 15% by weight of at least one polyether polyol which can be obtained by reacting 2- to 6-valent alcohols which have 2 to 10 C atoms with alkylene oxides containing 2 to 4 C atoms and reaction of these reaction products with 1,2 to 8 alkylene oxides containing 8 to 30 C atoms, alkyl or alkenyl glycidyl ethers and
• (c) 1 to 40% by weight of at least one acid.

The detergent formulations can optionally contain further, conventional constituents, such as solubilizers, corrosion inhibitors and builders.

The aqueous acidic cleaning formulations contain, as an essential component (a), at least one nonionic surfactant based on alkoxylated fatty alcohols, fatty acids, fatty amines, fatty acid amides or alkanesulfonamides. These compounds are addition products of 3 to 40 moles of ethylene oxide with 1 mole of fatty alcohols, fatty acids, fatty amines, fatty acid amides or alkanesulfonamides each containing at least 8 carbon atoms. The adducts of 3 to 20 moles of ethylene oxide with 1 mole of at least one alcohol having 10 to 18 carbon atoms are particularly preferred for use in the preparation of the aqueous acidic cleaner formulations. Suitable alcohols are preferably coconut oil or tallow fatty alcohols, oleyl alcohol or synthetically produced alcohols with 8 to 18 carbon atoms. The synthetic alcohols are produced, for example, by the Oxo process or the Ziegler process. Preferred alcohols are, for example, isodecanol, decanol, isotridekanol and mixtures of C₁₃ / C₁₅ fatty alcohol mixtures and C₁₆ / C₁₆ fatty alcohol mixtures. The particularly preferred ethoxylated fatty alcohols contain 3 to 16 moles of ethylene oxide per mole of alcohol. The amount of nonionic surfactants in the aqueous acidic cleaning formulations is 1 to 20, preferably 5 to 15% by weight.

The aqueous acidic cleaning formulations contain, as a further essential component, at least one polyether polyol which can be obtained by reacting 2 to 6-valent alcohols which have 2 to 10 C atoms with alkylene oxides containing 2 to 4 C atoms and reacting these reaction products with 8 1,2-alkylene oxides, alkyl or alkenyl glycidyl ethers containing up to 30 C atoms, compounds of this type are described, for example, in US Pat. Nos. 4,649,224, 4,665,239 and 4,709,099. The polyether polyols of component (b) are mixed in one at least 2-step process. In the first stage of the process, ethylene oxide or first ethylene oxide and then an alkylene oxide with 3 or 4 carbon atoms are added to a polyfunctional alcohol with 2 to 10 carbon atoms and 2 to 6 hydroxyl groups. In the second reaction stage, at least 1 alkylene oxide having 8 to 30 carbon atoms or an alkyl or alkenyl glycidyl ether having 8 to 30 carbon atoms in the alkyl or alkylene radical is added to the reaction product thus obtained. If mixtures of alkylene oxides with 2 to 4 carbon atoms are used in the first reaction stage, one can either use random copolymers (ie the reaction is carried out with mixtures of alkylene oxides carried out) or block copolymers. The block copolymers are formed by first reacting the compounds to be alkoxylated, for example, with ethylene oxide and then with propylene oxide or a butylene oxide. The alkylene oxides are added in a known manner to 2- to 6-valent alcohols. These polyfunctional alcohols can be alkane polyols, alkene polyols, alkyne polyols or oxialkylene polyols. Examples of alkane polyols are ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, trimethylolpropane, pentaerythritol, glycerol, 2,3,4,5- Hexantetrol, glucose and similarly structured sugars. Examples of alkene polyols are 2-butene-1,4-diol, 2-hexene-1,4,6-triol, 1,5-hexadiene-3,4-diol, 3-heptene-1,2,6,7- tetrol. Examples of alkyne polyols are 2-butyne-1,4-diol, 2-hexyne-1,4,6-triol and 4-octyne-1,2,7,8-tetrol. In the present context, oxyalkylene glycols are said to include diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol and the like. Connections are understood. Of the polyfunctional alcohols mentioned, trimethylolpropane, pentaerythritol, ethylene glycol and diethylene glycol are preferably suitable for the preparation of the polyether polyols according to (b). At least one sufficient amount of an alkylene oxide with 2 to 4 carbon atoms is added to 1 mol of the polyhydric alcohol to produce products which contain up to 90% by weight of oxyalkylene units of alkylene oxides containing 2 to 4 carbon atoms. However, the alkylene oxide addition product produced in the first stage of the reaction can also consist entirely of oxyethylene units. In addition to the pure ethylene oxide adducts to the polyhydric alcohols in question, reaction products of the polyhydric alcohols with ethylene oxide and propylene oxide which contain ethylene oxide and propylene oxide in a weight ratio of 70:30 to 95: 5 added to a polyhydric alcohol are of interest. This can be either statistical polymers or block copolymers.

In the second stage for the preparation of the polyether polyols (b), the polyhydric alcohols prepared in the first process stage and reacted with C₂- to C₄-alkylene oxides are reacted with 1,2-alkylene oxides containing 8 to 30 C atoms. Instead of the 1,2-alkylene oxides, 1,2-alkyl or 1,2-alkenyl glycidyl ether can also be used. The preparation of such glycidyl ethers is known, for example, from US Pat. No. 4,086,279. Suitable long-chain alkylene oxides are, for example, 1,2-epoxyoctane, 1,2-epoxydodecane, 1,2-epoxyhexadecane, 1,2-epoxyoctacosane and mixtures of the epoxides mentioned and the commercially available mixtures of epoxides which have 10 to 20 carbon atoms. Examples of alkyl glycidyl ethers are dodecyl, tetradecyl, hexadecyl, octadecyl, eicosyl, 2-methyldodecyl, 2-methyltetradecyl, 2-methylpentadecyl, 2-hexyldecyl or 2-octyldodecylglycidyl ether. Alkenyl glycidyl ether is preferably oleyl glycidyl ether.

As is known, the alkoxylations in the first and second reaction stages for the preparation of the polyether polyols are preferably carried out in the presence of bases such as sodium hydroxide solution or potassium hydroxide solution, at higher temperatures, e.g. up to temperatures of 160 ° C. The reaction products obtained in the second stage contain the long-chain 1,2-alkylene oxide or the long-chain glycidyl ether in an amount of 0.5 to 75, preferably 1 to 20% by weight in the attached form. Amounts of 1,2-alkylene oxides having 8 to 30 carbon atoms or the corresponding glycidyl ethers in the polyether polyol are particularly preferred such that the average molar ratio of longer-chain epoxide or glycidyl ether to each individual hydroxyl group of the polyhydric alcohol is preferably between 0.5 and 5 0.5 to 1.5. The molecular weight of the polyether polyols of component (b) of the cleaner formulations is 1000 to 75,000 and is preferably in the range from 5000 to 25,000. The 1,2-alkylene oxides with 8 to 30 C atoms or the glycidyl ethers used in their place 0.5 to 75, preferably 1 to 20 wt .-% involved in the structure of the polyether polyols. The polyether polyols described are used in amounts of 0.1 to 15, preferably 0.15 to 10% by weight in aqueous acidic cleaner formulations. In such formulations, together with the nonionic surfactants specified under (a), they produce a synergistic effect with regard to the increase in viscosity. The viscosities of the aqueous acidic cleaning formulations are preferably 100 to 19000 mPa.s.

As component (c) of the cleaning formulations, inorganic or organic acids are suitable, e.g. Hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, oxalic acid and citric acid or dicarboxylic acid mixtures (e.g. from succinic acid, glutaric acid and adipic acid). Acidic phosphoric acid esters as well as amidosulfonic acid and propanesulfonic acid are also suitable. The cleaning formulations contain 1 to 40, preferably 5 to 20% by weight of at least one acid.

In addition to the components (a) to (c) mentioned, the acidic cleaning formulations contain water to make up to 100% by weight. The cleaner formulations may also contain other constituents, such as solubilizers, corrosion inhibitors or builders. Solubilizers are, for example, compounds such as isopropanol, glycol ether, cumene sulfonic acid or their alkali salts.

The solubilizers are used in an amount of up to 10% by weight, based on the overall formulation. The cleaner formulations can also contain corrosion inhibitors, which may be used in amounts of up to 1% by weight. Suitable corrosion inhibitors are, for example, for HCl / H₂SO₄. Butynediol-1.4 with application amounts of 0.1 to 0.2% for 10% effectively present acid or for H₃PO₄ methylphenylthiourea with 0.5%, based on 20% effectively present acid.

The cleaner formulations may also contain builders if necessary. These are, for example, compounds such as acidic salts of phosphoric acid, sulfuric acid etc. (sodium hydrophosphate, sodium bisulfate).

The amount of builders in the detergent formulation is up to 20% by weight.

The aqueous acidic cleaner formulations described above are used to clean hard surfaces. The removal of calcium and magnesium carbonate deposits from pipelines or heat exchangers which are operated with hard water may be mentioned as an example. The acidic cleaner formulations are also used in dairies, for example to remove lactic acid deposits from objects made of metal, porcelain or ceramics.

The parts given in the following examples are parts by weight, the data in% relate to the weight of the substances.

The viscosities were measured in a Couette rotary viscometer at 20 ° C and a shear of 150 seconds⁻¹. The molecular weights of the substances are average molecular weights after the number average.

Verdicker A:

Polyetherpolyol mit einem Molekulargewicht von ca. 17 000 das durch Umsetzung von 1 Mol Trimethylolpropan mit einer Mischung aus 102 Mol Ethylenoxid und 19 Mol Propylenoxid und anschließende weitere Umsetzung des Alkoxylierungsproduktes mit 3 Mol eines 1,2-Alkylenoxids mit 16 Kohlenstoffatomen erhältlich ist. Der Anteil an langkettigem Alkylenoxid betrug 4,06 Gew.-%.

Verdicker B:

Polyetherpolyol mit einem Molekulargewicht von ca. 17 000, das durch Umsetzung von 1 Mol Trimethylolpropan mit 85 Teilen Ethylenoxid und 15 Teilen Propylenoxid und anschließende weitere Umsetzung mit 3 Äquivalenten eine Gemisches von 1,2-Alkylenoxiden mit 15 bis 18 Kohlenstoffatomen in der Alkylenkette erhältlich ist. Der Anteil an längerkettigem gebundenem Alkylenoxid betrug 4,18 Gew.-%.

Verdicker C:

Polyetherpolyol mit einem Molekulargewicht von ca. 17 000, das durch Umsetzung von 1 Mol Trimethylolpropan mit 280 Mol Ethylenoxid und anschließende weitere Umsetzung mit 3 Äquivalenten eines 1,2-Alkylenoxids mit 12 Kohlenstoffatomen erhalten wurde. Der Anteil des längerkettigen Alkylenoxids betrug 3,17 Gew.-%.

Verdicker D:

Polyetherpolyol mit einem Molekulargewicht von ca. 17 000, das durch Umsetzung von 1 Mol Trimethylolpropan mit 380 Mol Ethylenoxid und anschließende weitere Umsetzung mit 3 Äquivalenten eines 1,2-Alkylenoxids mit 18 Kohlenstoffatomen erhalten wurde. Der Gehalt an eingebautem C₁₈-Alkylenoxid betrug 4,55 Gew.-%.

The following polyether polyols were used as thickeners (component (b)):

Thickener A:

Polyether polyol with a molecular weight of approximately 17,000 which is obtainable by reacting 1 mol of trimethylolpropane with a mixture of 102 mol of ethylene oxide and 19 mol of propylene oxide and then further reacting the alkoxylation product with 3 mol of a 1,2-alkylene oxide with 16 carbon atoms. The proportion of long-chain alkylene oxide was 4.06% by weight.

Thickener B:

A polyether polyol with a molecular weight of approximately 17,000, which is obtainable by reacting 1 mol of trimethylolpropane with 85 parts of ethylene oxide and 15 parts of propylene oxide and subsequent further reaction with 3 equivalents, a mixture of 1,2-alkylene oxides with 15 to 18 carbon atoms in the alkylene chain . The proportion of longer-chain bound alkylene oxide was 4.18% by weight.

Thickener C:

Polyether polyol with a molecular weight of approximately 17,000, which was obtained by reacting 1 mol of trimethylolpropane with 280 mol of ethylene oxide and then further reacting with 3 equivalents of a 1,2-alkylene oxide with 12 carbon atoms. The proportion of the longer-chain alkylene oxide was 3.17% by weight.

Thickener D:

Polyether polyol with a molecular weight of approximately 17,000, which was obtained by reacting 1 mol of trimethylolpropane with 380 mol of ethylene oxide and then further reacting with 3 equivalents of a 1,2-alkylene oxide with 18 carbon atoms. The built-in C₁₈ alkylene oxide content was 4.55% by weight.

Tensid I:

Anlagerungsprodukt von 7 Mol Ethylenoxid an 1 Mol Isodecanol.

Tensid II:

Anlagerungsprodukt von 8 Mol Ethylenoxid an 1 Mol Isotridecanol.

Tensid III:

Anlagerungsprodukt von 7 Mol Ethylenoxid an 1 Mol eines C₁₃/C₁₅-Fettalkohol-Gemisches.

Tensid IV:

Anlagerungsprodukt von 3 Mol Ethylenoxid an 1 Mol eines C₁₃/C₁₅-Fettalkohol-Gemisches.

Tensid V:

Anlagerungsprodukt von 5 Mol Ethylenoxid am 1 Mol eines C₁₃/C₁₅-Fettalkohol-Gemisches.

Tensid VI:

Anlagerungsprodukt von 11 Mol Ethylenoxid an 1 Mol eines C₁₃/C₁₅-Fettalkohol-Gemisches.

Tensid VII:

Anlagerungsprodukt von 11 Mol Ethylenoxid an 1 Mol eines C₁₆/C₁₈-Fettalkohol-Gemisches.

Tensid VIII:

Anlagerungsprodukt von 5 Mol Ethylenoxid an 1 Mol Isotridecanol.

Tensid IX:

Anlagerungsprodukt von 10 Mol Ethylenoxid an 1 Mol C₉-Alkylphenol.

Tensid X:

Anlagerungsprodukt von 8 Mol Ethylenoxid an 1 Mol eines C₁₃-/C₁₅-Fettalkohols.

The following surfactants were used in the cleaner formulations:

Surfactant I:

Addition product of 7 moles of ethylene oxide with 1 mole of isodecanol.

Surfactant II:

Addition product of 8 moles of ethylene oxide with 1 mole of isotridecanol.

Surfactant III:

Addition product of 7 moles of ethylene oxide with 1 mole of a C₁₃ / C₁₅ fatty alcohol mixture.

Surfactant IV:

Addition product of 3 moles of ethylene oxide with 1 mole of a C₁₃ / C₁₅ fatty alcohol mixture.

Surfactant V:

Addition product of 5 moles of ethylene oxide on 1 mole of a C₁₃ / C₁₅ fatty alcohol mixture.

Surfactant VI:

Addition product of 11 moles of ethylene oxide with 1 mole of a C₁₃ / C₁₅ fatty alcohol mixture.

Surfactant VII:

Addition product of 11 moles of ethylene oxide with 1 mole of a C₁₆ / C₁₈ fatty alcohol mixture.

Surfactant VIII:

Addition product of 5 moles of ethylene oxide with 1 mole of isotridecanol.

Surfactant IX:

Addition product of 10 moles of ethylene oxide with 1 mole of C₉-alkylphenol.

Surfactant X:

Addition product of 8 moles of ethylene oxide with 1 mole of a C₁₃- / C₁₅ fatty alcohol.

The following aqueous acidic cleaner formulations according to the examples were prepared by mixing the surfactant, thickener, acid and water:
10% surfactant
X% thickener
20% acid
70-X% water.

A thickener-free formulation of the following composition was examined as a comparison:
15% surfactant
20% acid and
65% water.

The composition of the aqueous acidic cleaner formulations produced in each case and the viscosity of these formulations is given in Table 1. The experiments were numbered consecutively; as far as comparative examples are concerned, this has been indicated in the table with the addition (comparison).

As can be seen from the examples in Table 1, aqueous acidic cleaner formulations are obtained according to the invention which have greatly increased viscosities compared to the corresponding thickener-free cleaner formulations.

Example 2

Aqueous acidic cleaner formulations, the composition of which is shown in Table 2, were prepared in accordance with the standard formulation given in Example 1. The table also provides information about the viscosity of the detergent formulations.

The compositions given in Table 2 under Nos. 4, 6 and 8 are examples according to the invention, the other compositions are for comparison. As can be seen from Table 2, the selection of the surfactant plays a decisive role for the desired high viscosity of a detergent formulation. An ethoxylated alkylphenol as a surfactant (comparison No. 2 from Table 2) does not give the desired increase in viscosity, while the surfactants III, X and VII on the other hand lead to a surprisingly increased viscosity of the detergent formulation.

Claims (3)

1. An aqueous acidic surfactant-containing cleaner formulation which contains

   (a) from 1 to 20% by weight of one or more nonionic surfactants based on oxyalkylated fatty alcohols, fatty acids, fatty amines, fatty amides or alkanesulfonamides,

   (b) From 0.1 to 15% by weight of one or more polyetherpolyols which are obtainable by reacting a dihydric to hexahydric alcohol of 2 to 10 carbon atoms with an alkylene oxide of 2 to 4 carbon atoms and reacting this product with a 1,2-alkylene oxide or alkyl or alkenyl glycidyl ether of 8 to 30 carbon atoms and

   (c) from 1 to 40% by weight of one or more acids,

   the percentages in each case being based on the weight of the total formulation.
2. An aqueous acidic cleaner formulation as claimed in claim 1, which contains

   (a) an adduct of from 3 to 40 moles of ethylene oxide with 1 mole of a fatty alcohol, fatty acid, fatty amine, fatty amide or alkanesulfonamide, each of not less than 8 carbon atoms,

   as a component
3. An aqueous acidic cleaner formulation as claimed in claim 1, which contains

   (a) an adduct of from 3 to 20 moles of ethylene oxide with 1 mole of one or more alcohols of 8 to 18 carbon atoms and

   (b) a polyetherpolyol which is obtainable by reacting a dihydric to hexahydric alcohol of 2 to 6 carbon atoms with ethylene oxide and/or propylene oxide and then reacting this product with a 1,2-alkylene oxide of 8 to 30 carbon atoms, has a molecular weight of from 1,000 to 75,000 and contains from 0.5 to 75% by weight of the long-chain alkylene oxide as incorporated units.