WO1991008034A1 - Use of thiodiglycol derivatives as foam inhibitors - Google Patents

Abstract

The invention describes the use as foam inhibitors, in industry and in the home, of the mono and/or bis ethers and the mono and/or bis esters of thiodiglycolsulphoxides and/or sulphones of general formula (I), in which X1? and/or X2? are $g(b)-hydroxy-substituted alkyl residues with 8-30 C-atoms and/or acyl residues derived from alkylmonocarboxylic acids with 8-30 C-atoms, and z is the number 1 or 2.

Description

 "Use of thiodiglycol derivatives as foam inhibitors"

The invention describes the foam-inhibiting effect of the mono- and / or bis-ethers and mono- and / or bis-esters of thiodiglycol sulfoxides and / or sulfones of the general formula I

in der X₁ und/oder X₂ ß-hydroxylsubstituierte Alkylreste mit 8 bis 30 C-Atomen und/oder Acylreste von Alkylmonocarbonsäuren mit 8 bis 30 C-Atomen bedeuten, in der X₁ und X₂ gleich oder verschieden sind, wobei im Falle der Mono-ether bzw. Mono-ester X₁ oder X₂ gleich Wasserstoff ist und in der die Zahl z für 1 oder 2 steht, in aktivchlorhaltigen Reinigungsmitteln, bei der Zuckergewinnung und in Dispersionsfarben.

in which X ₁ and / or X ₂ mean β-hydroxyl-substituted alkyl radicals with 8 to 30 C atoms and / or acyl radicals of alkyl monocarboxylic acids with 8 to 30 C atoms, in which X ₁ and X _{2 are} identical or different, in which case the monoether or monoester X ₁ or X ₂ is hydrogen and in which the number z stands for 1 or 2, in detergents containing active chlorine, in sugar production and in emulsion paints.

An example of detergents containing active chlorine are dishwashing detergents for machine use, but the invention is not restricted to these. Shaped, granulated or liquid alkaline cleaning agents are used which essentially consist of builders, alkali metal silicates, alkali metal carbonates and / or alkali metal hydroxides and additionally contain active chlorine compounds. A foam inhibitor is usually added to prevent excessive foaming. Polychlorinated cyanuric acids and their salts, in particular trichloroisocyanuric acid, have proven successful as active chlorine compounds in powdery, granulated, liquid or liquid-pasty dishwashing detergents.

Up to now, low-foam, nonionic surfactants which correspond to the scheme fatty alcohol-EO _x -PO _y -, oxo alcohol-EO _x -PO _y or EO / PO block polymers have mostly been used as foam inhibitors, but they have the disadvantage that they are only limited in dishwashing detergents are stable in storage. This deficiency manifests itself in two respects: on the one hand, the nonionic surfactants used as foam inhibitors are chemically decomposed during storage and thus lose their foam-inhibiting effect. In the majority of cases, the corresponding decomposition products lead to stronger foaming. On the other hand, such dishwashing detergents stored over several weeks can suffer a loss of effective active chlorine.

The applicant's German patent DE 28 51 832 already contains sulfoxides or sulfones of the general formula II

worin R¹ einen Alkylrest mit 1 bis 22 C-Atomen, R² Wasserstoff oder einen Alkylrest mit 1 bis 22 C-Atomen, R³ einen Alkylrest mit 1 bis 22 C-Atomen oder den Rest CHR²-CHOH-R¹ und n die Zahlen 0, 1 oder 2 bedeuten, mit der Maßgabe, daß mindestens einer der Reste R¹-CHOH-CH-R² 10 bis 24 Kohlenstoffatome enthält, als Schauminhibitoren sowohl in Wasch- und Reinigungsmitteln als auch in Kunstharzdispersionen bekannt.

wherein R ^{1 is} an alkyl radical with 1 to 22 C atoms, R ^{2 is} hydrogen or an alkyl radical with 1 to 22 C atoms, R ^{3 is} an alkyl radical with 1 to 22 C atoms or the radical CHR ² -CHOH-R ¹ and n the numbers 0, 1 or 2, with the proviso that at least one of the radicals R ¹ -CHOH-CH-R ^{2 contains} 10 to 24 carbon atoms, are known as foam inhibitors both in detergents and cleaning agents and in synthetic resin dispersions.

The compounds of the general formula II are obtainable according to DE-OS-1768266 and DE-OS-1948385 by the applicant by reacting epoxides with hydrogen sulfide or alkyl mercaptans or by reacting mixtures of epoxides and olefins with hydrogen sulfide. The subsequent oxidation of the resulting sulfides (n = 0) leads to the corresponding sulfoxides (n = 1) or sulfones (n = 2) using methods known from the literature, for example by oxidation with hydrogen peroxide, nitric acid or potassium permanganate.

A major disadvantage of this synthetic route consists in the production of the sulfide building blocks, which is complex and expensive for industrial purposes, since the handling of the unpleasant smelling raw materials, hydrogen sulfide or alkyl mercaptans, is undesirable.

It has now surprisingly been found that selected thiodiglycol derivatives in cleaning agents of the type concerned here are effective foam inhibitors which are neither destroyed by active chlorine compounds nor in turn reduce the active chlorine content of the corresponding cleaning agents or damage the compounds containing active chlorine. The present invention accordingly relates to the use of the mono- and / or bis-ethers and mono- and / or bis-esters of thiodiglycolsulfoxides or sulfones of the general formula I

in which X ₁ and / or X ₂ mean β-hydroxyl-substituted alkyl radicals with 8 to 30 C atoms and / or acyl radicals of alkyl monocarboxylic acids with 8 to 30 C atoms, in which X ₁ and X _{2 are} identical or different, in which case the mono-ether or mono-ester X ₁ or X ₂ is hydrogen and in which the number z stands for 1 or 2, as foam inhibitors in the household and commercial sector.

The not yet published patent application by the applicant (D 7892) relates to the new thiodiglycol derivatives according to the invention, processes for their preparation and their use as plasticizers for textiles. They can be produced by reacting thiodiglycol with α-olefin epoxide compounds having 8 to 30 carbon atoms in the molecule or by reacting the thiodiglycol with alkyl monocarboxylic acids of comparable chain length.

Depending on the molar ratio between thiodiglycol and α-olefin epoxide compound (1: 1 to 1: 2), ring opening results in the formation of the corresponding mono- and / or bis-ether of thiodiglycol of general formula I in X ₁ and / or X ₂ ß -Hydroxylalkyl groupings. In a preferred embodiment the thiodiglycol is reacted in the desired molar ratio (1: 1 to 1: 2) with the C ₈ to C ₃₀ -α-olefin epoxide in such a way that a conventional basic catalyst, such as an alkali metal hydroxide and / or an alkali metal methoxylate, in an amount of at least 0.05 to about 5% by weight, preferably from about 0.1 to 1% by weight, based in each case on the total weight. The reaction of thiodiglycol with α-olefin epoxides of the chain lengths mentioned can in principle also be catalyzed by acids.

The actual reaction takes place at temperatures of at least 140 to about 200 °, preferably from 160 to 170 ° within about 3 to 6 hours to an epoxy content of below 0.5, preferably below 0.2. The epoxy content is used for constant reaction control and ultimately also for determining the quantitative course of the reaction.

When the thiodiglycol is reacted with the alkyl monocarboxylic acids or their reactive derivatives, depending on the molar ratio of thiodiglycol to alkyl monocarboxylic acid (1: 1 to 1: 2), the corresponding compounds of the general formula I of the mono- and / or bis-ester type are formed. The resulting reaction products of the mono- and / or bis-ether or mono- and / or bis-ester type of thiodiglycol are then in a manner known per se, for example with a certain amount of 70% hydrogen peroxide in glacial acetic acid to the sulfoxide (z = 1) and / or with the comparatively at least double the amount of 70% hydrogen peroxide in glacial acetic acid to the sulfone (z = 2) of the general formula I oxidized. Within the comparatively broad framework defined by general formula I of the new thiodiglycol derivatives according to the invention, selected narrow subclasses are particularly distinguished by their particular suitability for the aim as foam inhibitor aimed at according to the invention. Accordingly, it is preferred according to the invention that the radicals X ₁ and X _{2 are derived} from β-hydroxyl-substituted alkyl radicals or from acyl radicals having 12 to 24 carbon atoms and in particular having about 12 to 18 carbon atoms. The preferred residues of this type for X ₁ and X ₂ are corresponding straight-chain residues.

Compounds of the general formula I fall within the scope of the invention which are distinguished by the fact that different radicals of the type indicated are present in X ₁ and X ₂ , so that corresponding mixed radicals of the type defined according to the invention are present in the respective molecule. Structurally identical, but if desired also structurally different, radicals can be present in X ₁ and X ₂ . For reasons of easier accessibility, however, structurally identical radicals are preferred which, in the case of the compounds with mixed radicals X ₁ and X _2, then contain, for example, corresponding radicals of different chain lengths.

The thiodiglycol derivatives and their mixtures according to the invention are usually solid at room temperature and have melting points in the range from 60 to 200 °. To facilitate their processing, but in particular also to improve their foam-inhibiting effect, it can be advantageous to disperse the thiodiglycol derivatives in a liquid carrier. In this way, the finely divided, flowable dispersions of the foam inhibitors in the liquid carrier phase are particularly easy to get into the Incorporate alkaline dishwashing detergent containing active chlorine. In addition to water, suitable liquid carriers are, above all, organic compounds which have a sufficiently low pour point or melting point, preferably less than 5 ° C. It can also be advantageous to select flowable carriers or carrier mixtures which have a comparatively high viscosity and contribute to the stabilization of the dispersions. The liquid carrier phase can in turn have a defoaming effect or can only serve as a carrier for the defoamer in the sense of the invention.

Particularly suitable organic carrier liquids with an additional defoaming effect are mineral oils with a boiling point above 140 ° C. and branched-chain alcohols with 8 to 32 carbon atoms, for example 2-hexyldecanol-1 or 2-octyldodecanol-2. Liquid esters of branched or unsaturated fatty acids with 8 to 18 carbon atoms with mono- or polyhydric alcohols, for example glycol diesters or glycerol triesters of oleic acid, isostearic acid, and also esters based on branched-chain or unsaturated, liquid fatty acids with branched-chain or unsaturated fatty alcohols with 8 can also be used to 18 carbon atoms, for example isotridecyl alcohol or oleyl alcohol. Mixtures of the carrier substances mentioned can also be used according to the invention.

It is advantageous to use organic carrier substances in which the thiodiglycol derivatives dissolve at elevated temperature and excrete in finely divided form on cooling. For this purpose, the components are heated, homogenized and then rapidly cooled with vigorous stirring. Extremely fine and stable dispersions are obtained. However, it is also possible to use appropriate dispersions by stirring in the finely ground, to produce waxy thiodiglycol derivatives in the liquid phase.

The dispersions to be processed advantageously contain about 5 to 15% by weight of thiodiglycol derivatives of the general formula I. In addition, the dispersions of the thiodiglycol derivatives in the liquid carrier can be stabilized by suitable additives. Additives of approximately 0.3 to 3% by weight of magnesium stearate, calcium stearate or aluminum stearate are suitable, for example.

The defoamers and defoamer mixtures of the general formula I added to the alkaline active chlorine-containing cleaning agents show a sufficient defoaming action even in small amounts of 0.01 to 2% by weight. Their content is preferably not more than about 1% by weight, based on dry cleaning agent. An amount of the defoamer based on thiodiglycol sulfoxide and / or thiodiglycol sulfone in the range from about 0.05 to 0.5% by weight, based on the cleaning agent, is particularly preferred.

Dishwashing detergents which contain the foam inhibitors according to the invention can therefore have the following composition

(based on anhydrous substance):

35 to 65 wt .-%, preferably 40 to 60 wt .-% sodium metasilicate of the composition Na ₂ O: SiO ₂ = 1: 0.8 to 1: 1.1

 0 to 40% by weight, preferably 5 to 30% by weight sodium tripolyphosphate,

 0 to 10% by weight of finely divided, water-containing zeolite of the Na type,

0 to 15% by weight, preferably 0 to 5% by weight, of at least one polyanionic complexing agent from the class of the polymeric or co- polymeric polycarboxylic acids, hydroxyalkane polyphosphonic acids and aminoalkane polyphosphonic acids, each in the form of the sodium salt, 0 to 20% by weight, preferably 3 to 15% by weight sodium carbonate, 0 to 10% by weight, preferably 0 to 5% by weight sodium hydroxide, 0 to 10 wt .-%, preferably 0.5 to 5 wt .-% sodium silicate (water glass) of the composition Na ₂ O: SiO ₂ = 1: 3 to 1: 3.5 0.2 to 5 wt .-%, preferably 0.5 to 3% by weight of active chlorine compound, in particular trichloroisocyanuric acid or sodium or potassium dichloroisocyanurate,

 0.01 to 2 wt .-%, preferably 0.05 to 0.5 wt .-% of the defoamer according to the invention.

The preparation of the defoamer-containing cleaning agents or the incorporation of the defoamer or the defoamer dispersion can be done by mixing the dry individual components together with admixing the defoamer dispersion, by mixing under granulating conditions, that is to say simultaneous application of water or a water glass solution to the dry premix or also by subsequent addition Mix or spray the defoamer dispersion onto pre-formed granules. The type of preparation or the sequence in which the individual ingredients are added has no significant influence on the action or the interaction between defoamer and active chlorine compound.

In a particular embodiment of this invention, the foam inhibitors of the general formula I according to the invention can be used within sugar production. In addition to the foam-suppressing effect on substances such as cellulose, lignin, proteins, proteids, plant bases or, in particular, saponins, which are released from beet weed, sugar plays a role manufacturing the biodegradability and the food safety.

For the foam suppression according to the invention in the field of beet herb processing, about 1 to 15% by weight, preferably 5 to 10% by weight, of foam inhibitor of the general formula I, based on the defoamer composition, is generally sufficient. Within the scope of this invention, the defoamer composition further contains about 80 to 95% by weight of a commercially available mineral oil, 1 to 5% by weight of polypropylene glycol distearate (with an EO degree of 33 to 34%) and about 0.1 to 0.5% by weight of a metal stearate, preferably aluminum stearate. In a preferred embodiment of this invention, bis- [2- (2-hydroxyhexadecyloxy) ethyl] sulfone or a 1: 1 mixture of bis- [2- (2-hydroxydodecyloxy) ethyl] sulfone and bis- [2- (2-hydroxytetradecyloxy) ethyl] sulfone used.

The foam inhibitors of the general formula I according to the invention can also be used successfully in aqueous synthetic resin dispersions. Aqueous synthetic resin dispersions include, for example, polyvinyl acetates and copolymers of vinyl acetate with styrene, vinyl chloride, vinylidene chloride, vinyl alcohol, vinyl ethers, maleic acid, acrylic acid or its esters, crotonic acid, acrylamide and acrylonitrile.

About 1 to 15% by weight, preferably 5 to 10% by weight, based on the defoamer composition, is generally sufficient for effective foam suppression. The defoamer composition according to the invention also contains about 80 to 95% by weight of a commercially available mineral oil, 1 to 5% by weight of polypropylene glycol distearate (with an EO degree of 33 to 34%) and about 0.1 to 0.5% by weight of a metal stearate, preferably aluminum stearate.

For a long-lasting defoamer effect, defoamer particles that cannot be solubilized, saponified or hydrolyzed are particularly suitable. For this reason, the thiodiglycol derivatives of the mono- or bis-ether sulfone type, for example bis- [2- (2-hydroxyhexadecyloxy) ethyl] sulfone, are particularly preferably used.

Example A) General procedure for examining the defoaming effect of dishwashers containing active chlorine

2 eggs (approx. 100 - 110 g) were mixed with tap water (16 ° dH) in a ratio of 1: 1 and homogenized in a multimixer over a period of 2 minutes. Then 100 g of this emulsion were filled in a double-walled measuring cylinder with further tap water up to the 500 ml mark and heated to 50 ° C. After this test temperature had been reached, 20 g of dishwashing detergent containing active chlorine and defoamers were added and pumped around to generate foam using a peristaltic pump at a flow rate of 4 l / min. The resulting foam heights (see Table 3) were determined at intervals of 0.5, 1, 2, 3, 5, 10, 20 and 30 minutes.

The foam-inhibiting effect of the investigated dishwashing detergent - measured by the respective volume of foam and liquid phase - was determined immediately after the dishwashing detergent had been produced and after storage at 40 ° C. after a period of 3 months.

The following was used to test the defoamer effect

Dishwashing detergent composition selected:

 500 g sodium metasilicate, anhydrous

 370 g pentasodium tripolyphosphate hexahydrate

70 g Na ₂ CO ₃ (anhydrous)

 50 g Na water glass

10 g trichloroisocyanuric acid 10 or 30 g defoaming agent (see Table 3)

The components were mixed and granulated for 10 minutes at room temperature in a rotating drum while spraying the water glass solution.

The active chlorine content (Table 1) was determined as follows:

Approximately 5 g of the dishwashing detergent were dissolved in a 300 ml Erlenmeyer with 20 ml 10% KJ solution and 100 ml distilled water and after 10 minutes stirring at room temperature with 20 ml 85% phosphoric acid. The subsequent titration with 0.1 m Na ₂ S ₂ O ₃ solution (Fixanal ^R or Titrisol ^R ) was carried out until the color changed from brown to colorless. The active chlorine content was determined using the following formula:

[%] Active chlorine content

The foam-inhibiting effect of examples 1 to 4 according to the invention based on bisether sulfone and of comparative examples 5 to 12 became clear in particular in the light of examples 13 and 14, in which the dishwashing detergent did not contain any defoamer active ingredient. Surprisingly, Examples 1 to 4 showed a better and longer-lasting foam-inhibiting effect compared to the defoamer active ingredients known from the prior art (Examples 5 to 12), wherein the active chlorine content remained much more stable, especially in long-term trials.

¹ defoamer content in the dishwashing detergent composition in percent by weight

² Storage time at 40 ° C in months

³ Mixture of 5% bis- [2- (2-hydroxyhexadecyloxy) ethyl] sulfone and 95% 2-octyldodecanol

⁴ Geraisch from C ₁₂ / C ₁₄ fatty alcohols with 2 EO and 4 PO

⁵ Mixture of C ₁₂ / C ₁₈ fatty alcohols with 5 EO and 8 PO

⁶ dishwashing detergents without defoamer additive

B) General procedure for examining the foaming behavior during sugar extraction

110 g of beet herb and 420 ml of water (17 ° dH) were pumped around using a peristaltic pump (Heidolph) at a flow rate of 3 l / min until a constant foam height of about 2000 ml was reached. After the addition of 0.1 ml of defoamer (see Table 2) using a Microman pipette (Abimed), the total volumes were read off after 0.5, 1, 2, 3, 5 and 10 minutes at room temperature.

In comparison to the foam inhibitors known from the prior art (Table 2, Examples 3 to 6), the defoamers according to the invention (Examples 1 and 2) are surprisingly distinguished by an extremely rapid decrease in the foam volume.

C) General procedure for determining the foaming behavior in emulsion paints

100 ml of a 50% aqueous Mowilith DV 50 dispersion were diluted with 100 ml of distilled water and stirred in a 1 liter beaker for 2 minutes to determine the initial foam height at 2000 revolutions per minute. Then 0.5 ml of the corresponding defoamer (see Table 3) was added dropwise using a pipette and the time until 100% foam breakdown was determined with reduced stirring (800 revolutions per minute). After further stirring at 2000 revolutions per minute for a period of 1 minute, the final foam height was read off.

Surprisingly, in particular Examples 5 and 6 according to the invention (Table 3) had equivalent foam disintegration times and final foam heights compared to Comparative Examples 7 to 9.

Claims

Patent claims 1. Use of the mono- and / or bis-ethers and mono- and / or bis-esters of thiodiglycol sulfoxides or sulfones of the general formula (I)

in which X ₁ and / or X ₂ mean β-hydroxyl-substituted alkyl radicals with 8 to 30 C atoms and / or acyl radicals of alkyl monocarboxylic acids with 8 to 30 C atoms, in which X ₁ and X _{2 are} identical or different, in which case the mono-ether or mono-ester X ₁ or X ₂ is hydrogen and in which the number z stands for 1 or 2, as foam inhibitors in the household and commercial sector. 2. Embodiment according to claim 1, characterized in that compounds of general formula I are used in which X ₁ and X ₂ ß-hydroxyl-substituted alkyl radicals having 12 to 18 carbon atoms, in particular having 16 to 18 carbon atoms and z preferably the Number 2 mean. 3. Embodiment according to claims 1 to 2, characterized in that at least one foam inhibitor of the general formula I in an amount of at least 0.01 to 25 wt .-%, preferably 0.2 to 10% by weight, based in each case on the foaming substance, in detergents containing active chlorine, in sugar extraction or in emulsion paints. 4. Embodiment according to claim 3, characterized in that the foam inhibitor is used in detergents containing active chlorine in the form of a dispersion of 5 to 15% by weight foam inhibitor and 75 to 85% by weight of liquid organic carrier phase. 5. Embodiment according to claim 3 and 4, characterized in that the liquid organic carrier phase consists of at least one compound from the class of mineral oils with a boiling point above 140 ° C and from the class of 8 to 32 carbon atoms, optionally branched chain fatty alcohols . 6. Alkaline, active chlorine-containing cleaning agent according to one or more of claims 1 to 5, the 0.01 to 2 wt .-%, preferably 0.05 to 0.5 wt .-% of at least one foam inhibitor of the general formula I - based on the amount of detergent - contains.