EP0248197A2 - Use of polyglycol ethers containing amino groups as foam-retarding additives in low-foaming detergents - Google Patents

Abstract

in der X den Rest R³ - CHOH - CHR⁴ - (OCH₂CH₂)_n -, R¹ einen geradkettigen oder verzweigten Alkylrest mit 1 bis 6 Kohlen­stoffatomen, R² = R¹ oder den Rest X, R³ einen geradkettigen Alkylrest mit 6 bis 18 Kohlenstoffatomen, R⁴ Wasserstoff oder einen Alkylrest mit 1 bis 8 Kohlenstoffatomen und n eine Zahl von 3 bis 20 bedeuten mit der Maßgabe, daß die Summe der in R³ und R⁴ enthaltenen Kohlenstoffatome 6 bis 18 beträgt.Suitable foam inhibitors for low-foaming cleaning agents are hydroxyalkylpolyethylene glycol ethers of the formula containing amino groups

in which X is R³ - CHOH - CHR⁴ - (OCH₂CH₂) _n -, R¹ is a straight-chain or branched alkyl radical with 1 to 6 carbon atoms, R² = R¹ or X, R³ is a straight-chain alkyl radical with 6 to 18 carbon atoms, R⁴ is hydrogen or an alkyl radical with 1 to 8 carbon atoms and n is a number from 3 to 20 with the proviso that the sum of the carbon atoms contained in R³ and R⁴ is 6 to 18.

The foam inhibitors are resistant to strong alkalis and strong acids. Their application concentration is 10 to 500 ppm.

Description

The invention relates to the use of aminoalkyl-containing hydroxyalkyl polyethylene glycol ethers as foam-suppressing additives in low-foam cleaning agents.

Aqueous cleaning agents intended for use in trade and industry, in particular those for cleaning metal, glass and ceramic and plastic surfaces, as a rule contain substances which are able to counteract undesirable foam development. In most cases, the use of foam-suppressing additives is due to the fact that the contaminants detached from the substrates and accumulating in the cleaning baths act as foaming agents. In addition, the use of anti-foaming agents may also be necessary due to the fact that the cleaning agents themselves contain constituents which give rise to undesirable foaming under the given working conditions, for example anionic surfactants or nonionic surfactants foaming at working temperature.

in der X den Rest R³ - CHOH - CHR⁴ - (O CH₂CH₂)_n -, R¹ einen geradkettigen oder verzweigten Alkylrest mit 1 bis 6 C-Atomen, R² = R¹ oder den Rest X, R³ einen geradkettigen Al­kylrest mit 6 bis 18 Kohlenstoffatomen, R⁴ Wasserstoff oder einen Alkylrest mit 1 bis 8 Kohlenstoffatomen und n eine Zahl von 3 bis 20 bedeuten, mit der Maßgabe, daß die Summe der in R³ und R⁴ enthaltenen Kohlenstoffatome 6 bis 18 beträgt.The invention relates to the use of hydroxyalkyl polyethylene glycol aminoethers of the formula I below as foam-suppressing additives for low-foam cleaning agents:

in which X is R³ - CHOH - CHR⁴ - (O CH₂CH₂) _n -, R¹ is a straight-chain or branched alkyl radical with 1 to 6 C atoms, R² = R¹ or the radical X, R³ is a straight-chain alkyl radical having 6 to 18 carbon atoms, R⁴ is hydrogen or an alkyl radical having 1 to 8 carbon atoms and n is a number from 3 to 20, with the proviso that the sum of the carbon atoms contained in R³ and R⁴ is 6 to 18.

erhältlich, die ihrerseits durch Ethoxylierung der entsprechenden Dialkylamine erhalten werden. Geeignete Alkylreste sind beispiels­weise Methyl-, Propyl-, i-Propyl-, Butyl-, i-Butyl-, Amyl-, i-Amyl- und Hexylreste. Bevorzugte Diamine sind Dipropylamin, Diisopropylamin, Dibutylamin, und Diisobutylamin. Die Mono- bzw. Dialkylamine werden in bekannter Weise mit Ethylenoxid im Molver­hältnis von 1 : 3 bis 1 : 20, bezogen auf die Zahl der reaktions­fähigen Wasserstoffatome, umgesetzt.The starting material for the preparation of the compounds of the formula I with R² = X are ethoxylated monoalkylamines which can be obtained by reacting amines of the formula R¹ - NH₂ with ethylene oxide. Compounds with R¹ = R² are from ethoxylated dialkylamines of the formula II

available, which in turn are obtained by ethoxylation of the corresponding dialkylamines. Suitable alkyl radicals are, for example, methyl, propyl, i-propyl, butyl, i-butyl, amyl, i-amyl and hexyl radicals. Preferred diamines are dipropylamine, diisopropylamine, dibutylamine, and diisobutylamine. The mono- or dialkylamines are reacted in a known manner with ethylene oxide in a molar ratio of 1: 3 to 1:20, based on the number of reactive hydrogen atoms.

The ethoxylated mono- or dialkylamines are reacted, preferably in the presence of suitable alkaline catalysts, with epoxides of chain length C₈ - C₂₀. Both 1,2-epoxides and compounds with an internal epoxy group are suitable. 1,2-epoxides of chain length C₁₀-C₁₆ have proven to be particularly suitable. Mixtures of epoxides of different chain lengths are also suitable. The molar ratio of ethoxylated monoamine to epoxy is approximately 1: 2, the molar ratio of ethoxylated diamine to epoxy is approximately 1: 1. The addition of alkaline catalyst is 0.1 to 1 % By weight, based on the amount of epoxy used. The reaction is carried out by heating to temperatures of 140 to 180 ° C., preferably 150 to 170 ° C., for several hours. The degree of conversion can easily be determined by determining the epoxy content of the mixture. In general, heating at 150 to 170 ° C. for 1 to 3 hours is sufficient.

Further information on the reaction of polyglycol ethers with long-chain epoxides can be found in EP 88 039-A2.

Preferred compounds of formula I are derived from alkoxylated dialkylamines, i.e. those in which the radicals R¹ and R² represent alkyl radicals, R³ is a linear C₁₀ to C₁₆ hydrocarbon radical, R⁴ = H and n is a number from 5 to 15. In addition, particular preference is given to the use of compounds of the formula I in which R 1 and R 2 represent an n-propyl or n-butyl radical.

The compounds of the formula I can be used on their own or in combination with other foam inhibitors, in particular with polyethylene glycol ethers, such as those obtained by adding 4 to 20 parts by weight of ethylene oxide to 1 part by weight of polyglycerol with a hydroxyl number in the range from 900 to 1200 and subsequent etherification of the free Hydroxyl groups with alkyl halides with 4 to 8 carbon atoms are available and are described in DE-PS 33 15 952 (D 6562). Such mixtures of the polyglycol ethers of the formula I and the end group-capped polyglycerol polyglycol ethers defined above in a weight ratio of 1: 1 to 9: 1, preferably from 2.3: 1 to 9: 1, have a particularly pronounced foam-suppressing effect.

The compounds to be used according to the invention are liquid at room temperature. They are characterized by a high alkali and acid stability and a very effective foam inhibition in weakly acidic to strongly alkaline cleaning solutions.

The cleaning agents in which the compounds of the formula I are used according to the invention can contain the constituents customary in such agents, such as wetting agents, builders and complexing agents, alkalis or acids, corrosion inhibitors and, if appropriate, also antimicrobial active substances and / or organic solvents. Non-ionic surface-active substances, such as polyglycol ethers, which are obtained by addition of ethylene oxide to alcohols, in particular fatty alcohols, alkylphenols, fatty amines and carboxamides, and anionic surfactants, such as alkali metal, amine and alkylolamine salts of fatty acids, alkylsulfonic acids, alkylsulfonic acids and alkylbenzenesulfonic acids, come as wetting agents Consider. The builders can include alkali metal orthophosphates, polymer phosphates, silicates, borates, carbonates, polyacrylates and gluconates as well as citric acid, nitriloacetic acid, ethylenediaminetetraacetic acid, 1-hydroxyalkane-1,1-diphosphonic acid, aminephosphonic acids, amine and ethylenediaminetetra- (methylenephosphonic acid), phosphonoalkane polycarboxylic acids such as e.g. B. contain phosphonobutane tricarboxylic acid and alkali metal salts of these acids. Highly alkaline cleaning agents, especially those for bottle cleaning, contain considerable amounts of caustic alkali in the form of sodium and potassium hydroxide. If special cleaning effects are desired, the cleaning agents can contain organic solvents, for example alcohols, gasoline fractions and chlorinated hydrocarbons and free alkylolamines.

In connection with the invention, cleaning agents are once understood to mean the aqueous solutions intended for direct application to the substrates to be cleaned. In addition, the term cleaning agents also includes those for the production of Application solutions certain concentrates and solid mixtures.

The ready-to-use solutions can be slightly acidic to strongly alkaline.

The compounds of the formula I to be used according to the invention are added to the cleaning agents in amounts such that their concentration in the ready-to-use solutions is 10 to 2500 ppm, preferably 50 to 500 ppm.

Examples Preparation of the hydroxyalkyl polyglycol ether amines

349 g (1 mole) of adduct of 5 moles of ethylene oxide with 1 mole of dibutylamine, 212 g (1 mole) of linear 1,2-epoxytetradecane and 1.3 g of sodium ethylate (30% solution in methanol) were removed in vacuo to remove the with The catalyst introduced methanol was heated in vacuo to 100 ° C. and then heated to 160 ° C. under stirring under an inert gas atmosphere for 2 hours. After cooling, the reaction product was neutralized with the equivalent amount of acetic acid and filtered.

The hydroxyalkyl polyglycol dialkylaminoethers listed in Table I were prepared in the same way as in Examples 2 to 12. EO stands for attached ethylene oxide groups.

To prepare the compounds derived from monobutylamine according to Example 13, a mixture of 513 g (1 mol) of a n-butylamine reacted with 10 mol of ethylene oxide, 368 g (2 mol) of a linear 1,2-epoxydodecane and 2.5 g of sodium methylate was added Removal of the methanol heated to 160 to 170 ° C for 3 hours in an inert gas atmosphere. After cooling to 50 ° C, the catalyst was neutralized with acetic acid and the product was filtered. The products according to Example 14 were produced in an analogous manner.

Production of the end-capped polyglycerol polyethylene glycol ethers according to DE-PS 33 15 962

In an autoclave, 137 g of polyglycerol (hydroxyl number 961) were reacted with 1 488 g of ethylene oxide (weight ratio 1: 10.9) at 180 ° C. and 10 bar in the presence of 3 g of sodium methylate. 1,313 g of polyglycerol ethylene glycol ether with a hydroxyl number of 113 were obtained.

350 g of the product obtained, 171 g of n-hexyl chloride and 228 g of 75% by weight sodium hydroxide solution were added for 4 hours Stirred 120 ° C. The aqueous phase was separated from the cooled reaction mixture. The organic phase was washed with water at 50 ° C. until the washing liquid reacted neutral. Unreacted hexyl chloride and water were removed from the reaction mixture by heating to 150 ° C in vacuo. 281.5 g of polyglycerol polyethylene glycol hexyl ether (polyglycerol - 10.9 EO-butyl) were obtained. The hydroxyl number of the product was 3.5. The reaction product is referred to as Product B below.

Checking the defoaming effect

The antifoam effect was tested using test solutions which contained 1% by weight sodium hydroxide and 0.03% by weight (300 ppm) defoamer. These solutions were added in the course of the tests in increments of 100 ppm increasing amounts of triethanolamine tetrapropylene benzene sulfonate as a test foam.

200 ml portions of the test solutions were tested at 65 ° C in the foam whipping apparatus according to DIN 53 902. The foam volume in ml was read 5 seconds after a series of 100 beats in 100 seconds. An average value of 5 individual measurements was determined for each test foam concentration. In the second column of Table 2 below, the results obtained in each case show the foam volume which was observed at a test foam concentration of 1,000 ppm. The second representative measured value in the third column of Table 2 is the test foam concentration at which a foam volume above 200 ml was measured for the first time.

Example 15

A storage-stable, solid bottle cleaning agent of the following composition (GT = parts by weight) was produced by mechanical mixing of the components:
80 GT caustic soda
12 pbw of sodium tripolyphosphate
5 pbw of sodium silicate (molar ratio Na₂O: SiO₂ = 3.35)
3 GT product according to Example 1

Milk bottles were washed with a 1% by weight solution of this cleaning agent at 80 ° C. in a commercially available bottle cleaning system with a lye zone and an hourly output of 18,000 bottles cleaned. With a good cleaning effect, no disruptive foaming was observed.

Example 16

A stable, stable mixture of active substances of the following composition was obtained by mechanical mixing of the components:

80 pbw sodium tripolyphosphate
20 GT product according to Example 6

Beer bottles were cleaned at 85 ° C in a bottle cleaning system with three lye zones and an hourly output of 80,000 bottles. The beer bottles were labeled with paper labels using casein glue, which would otherwise cause excessive foaming in the immersion baths. If 1.5% by weight sodium hydroxide solution containing 0.15% by weight of the active substance mixture described above was used as the cleaning solution, the system could be operated without disruptive foaming.

Example 17

A storage-stable mixture of active ingredients of the following composition was obtained by mechanical mixing of the components
40 pbw of Na ethylenediaminetetraacetate
20 pbw sodium tripolyphosphate
30 pbw of sodium gluconate
10 GT product according to Example 1

Wine bottles were cleaned at 85 ° C in a commercially available bottle cleaning system with two separate lye zones and an hourly output of 244,000 bottles. As Reini solution was used 1.5 wt .-% sodium hydroxide solution to which 0.5 wt .-% of the concentrate described above had been added. The cleaning was done without disturbing foam development. The inserted bottles were cleaned perfectly.

Example 18

A detergent concentrate of the following composition was prepared by dissolving the components in phosphoric acid:
5 pbw of aminotri- (methylenephosphonic acid)
10 pbw of 1-hydroxyethane-1,1-diphosphonic acid
5 pbw of phophonobutane tricarboxylic acid
27 GT product according to example 1
3 GT product B
10 pbw of ethanol
40 pbw of phosphoric acid, 75% by weight

Mineral water bottles were cleaned at 80 ° C in a conventional bottle cleaning system with three caustic baths. A 2% by weight sodium hydroxide solution was used as the cleaning solution, to which 0.1% by weight of the concentrate described above had been added. The cleaning was done without disturbing foam development. The inserted bottles were cleaned perfectly.

Example 19

A storage-stable cleaning agent of the following composition was produced by mechanical mixing of the components for cleaning metallic surfaces by spraying:
80 pbw sodium metasilicate pentahydrate
16 pbw sodium tripolyphosphate
4 GT coconut amine + 12 EO
1 GT product according to Example 1

The foam formation and the foam randomness of a 2% by weight solution of this cleaning agent was tested according to DIN 53 902 at 60 ° C. in comparison to an agent without the addition of product A, but otherwise the same composition. The results are shown in Table 3.

Example 20

A mechanical degreasing agent for metallic materials with the following composition was produced by mechanical mixing of the components:
40 pbw sodium metasilicate pentahydrate
35 GT sodium carbonate
20 pbw sodium tripolyphosphate
2.5 pbw of sodium alkylbenzenesulfonate
2.5 pbw of nonylphenol + 14 EO
4.5 pbw product according to example 1
0.5 GT product B

A 4% by weight solution of this cleaning agent was used to clean fat-contaminated steel moldings at 60 ° C. in an immersion process. The degreasing effect was very good; no disruptive foaming was observed.

Example 21

A storage-stable concentrate for cleaning metal surfaces with the following composition was prepared by dissolving the components in water:
30 pbw of sodium caprylate
10 GT borax
14 pbw sodium tripolyphosphate
10 pbw of triethanolamine
2 pbw of monoethanolamine
6 GT product according to example 1
78 GT water

With a 1.5 wt .-% solution of the cleaning agent (pH 8.5) iron surfaces were cleaned at 50 to 55 ° C by spraying. With a good cleaning effect, no disruptive foam development occurred.

Example 22

By dissolving the components in water, a storage-stable concentrate for cleaning metal surfaces with the following composition was obtained:
25 pbw of diethanolamine salt of isononanoic acid
20 pbw diethanolamine
1 pbw of benzotriazole
4 GT product according to example 6
50 GT water

A 1% by weight solution of this cleaning agent was used at 50 to 55 ° C. for spray cleaning gray cast iron parts. With a good cleaning effect, no disruptive foaming was observed.

Claims (3)

1. Use of hydroxyalkyl polyethylene glycol amino ethers of the formula I as foam-suppressing additives for low-foam cleaning agents

in which X is R³ - CHOH - CHR⁴ - (OCH₂CH₂) _n -, R¹ is a straight-chain or branched alkyl radical with 1 to 6 carbon atoms, R² = R¹ or X, R³ is a straight-chain alkyl radical with 6 to 18 carbon atoms, R⁴ is hydrogen or an alkyl radical with 1 to 8 carbon atoms and n is a number from 3 to 20 with the proviso that the sum of the carbon atoms contained in R³ and R⁴ is 6 to 18. 2. Use of compounds according to claim 1, wherein R¹ and R² represent alkyl radicals having 3 to 4 carbon atoms. 3. Use of compounds according to claims 1 and 2, wherein n is a number from 5 to 15.