EP0272574B1 - Mixtures of liquid non-ionic surfactants - Google Patents

Abstract

A liquid mixture of propylene oxide/ethylene oxide derivatives of alcohols of the formula R-O-(C3H5O)1-2-(C2H4O)6-8-H in which R is an alkyl or alkenyl radical which is linear or methyl-branched in position 2 and which has the following chain distribution: C8 = 0 to 5 %, C9-10 = 75 to 90 %, C11-12 = 5 to 15 %, C13-14 = 4 to 10 %, C15-16 = 0 to 3 %, is, by reason of its physical and washing properties, suitable as readily biodegradable substitute for alkylphenol ethoxylates.

Description

The alkylphenol ethoxylates widely used today as nonionic surfactant components have a considerably better cold behavior (lower pour point and cold cloud point) than comparable ethoxylates based on linear fatty alcohols. In the area of alkylphenol ethoxylates, the nonylphenol-10 EO adduct (NP-10) in particular is characterized by such excellent application properties that it has a universally applicable surfactant for detergents and cleaning agents, but also an emulsifier for a large number of technical applications. In addition, this surfactant has very good degreasing properties, both on metal and on textile fabric. Because of these favorable properties, NP-10 is by far the most important representative in terms of quantity from the class of alkylphenol ethoxylates.

It is disadvantageous that the environmental compatibility of these alkylphenol ethoxylates gives cause for concern, so that considerable efforts are being made to at least partially replace these technologically high-quality surfactant components by components with better environmental compatibility. Alkoxylated fatty alcohols of natural and / or synthetic origin are particularly suitable for this. However, their use presents the following difficulty: ether alcohols of the latter type only have the hydrophilicity values desired in practice - cloud point, for example, in the range from about 50 to 60 ° C. - only in those embodiments in which the ether alcohols as such are solid at room temperature. This is a crucial one in practice Limitation in the attempt to replace the alkylphenol adducts with adducts of primary fatty alcohols.

The invention is based on the object of providing surfactant mixtures based on alkoxylated straight-chain and / or branched primary alcohols, in particular corresponding linear fatty alcohols, which are still liquid at low temperatures, for example at temperatures down to 5 ° C., and a can provide high surfactant performance. The invention has in particular the task of creating a surfactant mixture which is similar in its essential technological properties to the NP-10 and which are constructed exclusively on the basis of environmentally compatible components.

The invention accordingly relates to surfactant mixtures which are liquid at room temperature and are based on polyalkoxylated alcohols with a high surfactant output, consisting of a straight-chain or ether alcohol of the general formula which is methyl-branched in the 2-position



R - O - (PO) ₁₋₂ - (EO) ₆₋₈ - H



in the PO the rest of the ring-opened propylene oxide and EO the rest of the ring-opened ethylene oxide, characterized in that the alkyl or alkenyl radicals R are composed as follows: C₈ = 0 to 5% by weight, C₉₋₁₀ = 75 to 90 % By weight, C₁₁₋₁₂ = 5 to 15% by weight, C₁₃₋₁₄ = 4 to 10% by weight and C₁₅₋₁₆ = 0 to 3% by weight.

R preferably represents linear alkyl radicals of the following composition:
C₈ = 0 to 2% by weight, C₁₀ = 80 to 84% by weight, C₁₂ = 7 to 12% by weight, C₁₄ = 6 to 8% by weight and C₁₅₋₁₆ = 0 to 1% by weight %.

The mixture according to the invention is prepared in a manner known per se by two-stage alkoxylation of the alcohol mixture, propylene oxide being added in the first stage and ethylene oxide being added in the second stage. The starting alcohols are primarily mixtures obtained from coconut fatty alcohols, from which the majority of C₁₂-C₁₆ alcohols have been removed by distillation. Mixtures obtained from synthetic fatty alcohols, for example oxo alcohols, can also be used as starting materials. Such alcohols generally contain a proportion of alcohols branched methyl in the 2-position. However, preference is given to using the mixtures obtained from native alcohols, in which the alkyl radicals differ in each case by 2 carbon atoms.

As is known, the alkoxylation can be carried out in the presence of acidic or alkaline catalysts. Alkaline catalysts, such as hydroxides or alcoholates of potassium or sodium, are preferably used. Examples include NaOH, KOH, sodium methylate, sodium ethylate, potassium methylate and potassium ethylate. For faster and more homogeneous distribution in the substrate, the hydroxides and alcoholates can be used in alcoholic solution, after which the solution alcohol is removed by distillation before the alkoxylation. Usually 0.5 to 5%, preferably 1 to 3% catalyst, based on the starting material, is used. The alkoxylation can be carried out at normal pressure by introducing the alkylene oxides into the alcohol mixture. However, it is preferably carried out in an autoclave under an increased initial pressure, for example an initial pressure of 2 to 10 bar, preferably 3 to 6 bar. As the implementation progresses, the pressure then drops to normal pressure. The temperature of the alcohol to be alkoxylated is generally 80 to 200 ° C, usually 100 to 180 ° C. The alkoxylate can generally be used directly. If the small catalyst residues interfere, they can be neutralized, for example by adding organic acids such as acetic acid or citric acid. After the alkoxylation has ended, carbon dioxide can also be pressed into the autoclave and the precipitated alkali carbonate can be filtered off.

Alkoxylated fatty alcohols, in the production of which first propylene oxide and then ethylene oxide are added, are known per se. However, they differ considerably in the composition of the radical R from the mixtures according to the invention. For example, US Pat. No. 2,174,761 describes products which in some cases have considerably higher proportions of PO and are derived from cetyl or dodecyl alcohol. These have much higher solidification areas and are less biodegradable. DE 27 24 349-A1 describes spray-dried detergents which contain nonionic surfactants of a similar constitution, the alkyl radicals preferably having 12 to 18 carbon atoms and not consisting of mixtures with a predominant content of C₉ to C₁₀ alkyl radicals. The same applies to the detergent granules described in DE 28 37 504-C2. DE 28 10 703-A1 describes nonionic surfactants in a different order of the PO and EO groups. A comparative experiment, in which a mixed alcohol reacted with 4 mol PO and 15 mol EO with 43% C₁₂-alkyl residues and 57% C₁₃-alkyl residues (78% linear, 22% methyl branched) was examined, shows a comparatively high freezing point and an unfavorable washing result , which is why it was not to be expected that the mixtures according to the invention would offer significant advantages in this regard. Finally, DE 32 32 616 discloses liquid detergents which contain mixtures of nonionic surfactants with a comparable molecular structure. However, these alkoxylates are preferably derived from alcohols having 12 to 18 carbon atoms or mixtures of cetyl, oleyl and stearyl alcohol mixtures. Surfactant mixtures of the composition according to the invention are neither disclosed nor suggested.

Of particular advantage, especially compared to alkoxylated alkylphenols, is the very good biodegradability, which is above 96%. With regard to the performance properties, the nonionic surfactant mixture according to the invention is equivalent to the highest quality alkylphenol ethoxylates. This applies both to the compounds alone and to their mixtures with other additives and auxiliaries, as are usually used in detergents, cleaning agents, emulsifiers and dispersants.

In a further embodiment, the invention therefore relates to the replacement of nonylphenol-9- or 10 EO by the surfactant mixture defined according to the invention in known solid and liquid preparations, in particular detergents, wetting agents and dispersants.

In a further embodiment of the invention, the liquid nonionic surfactants can also be combined with other readily biodegradable nonionic compounds. With such combinations, the washing performance can be increased even further without having to accept disadvantages with regard to the other positive properties. Suitable additives are, for example, ethoxylates derived from primary alcohols or alkylamines having 10 to 18, in particular 10 to 14, carbon atoms and having an average of 1 to 4, preferably 2 to 3, EO groups. The mixing ratio with these additives can be 1: 2 to 10: 1. In addition, when used in detergents and cleaning agents, they can be combined with known anionic, nonionic, ampholytic zwitterionic and cationic surfactants, skeletal salts, sequestering agents, bleaching agents, graying inhibitors, anti-aging agents, foam inhibitors and other active ingredients conventionally used in such agents. The composite compositions can be in solid or granular or in liquid form. Of particular Of interest in the present case are liquid detergents, dishwashing detergents and cleaning agents, for which the alkoxylates according to the invention are particularly suitable on account of their low cloud temperatures and favorable solution properties.

Solid detergents can, for example, have the following composition (in% by weight of anhydrous substance):
0.5 to 25%, preferably 1 to 20%, of the nonionic surfactant mixture according to the invention,
0 to 25%, preferably 2 to 20%, of anionic surfactants from the class of alkali soaps and sulfonate surfactants, in particular C₉₋₁₃-alkylbenzenesulfonates, alpha-sulfofatty acid salts, alpha-sulfofatty acid alkyl ester salts and alkane sulfonates each with 12 to 18 carbon atoms in the aliphatic radical,
0 to 10% of nonionic C₁ bis₁₀₋ alcohol ethoxylates containing 2 to 15 EO groups,
10 to 70%, preferably 20 to 50%, of builder salts from the class of the phosphates, polyphosphates, carbonates, silicates of sodium, sodium nitrilotriacetate and finely divided zeolite of the NaA type,
0.1 to 5% of complexing agents from the class of the Na salts of polyphosphonic acids and of the homo- or copolymeric polymer carboxylic acids, in particular of hydroxyethane diphosphonate, of ethylenediaminetetramethylene phosphonate and of acrylic acid-maleic acid copolymers,
0 to 30%, preferably 5 to 20%, of per compounds and their combination with activators, in particular sodium perborate monohydrate and tetrahydrate and tetraacetylethylene diamine,
0 to 10% of other detergent components from the class of graying inhibitors, enzymes, optical brighteners, colors and fragrances,
0 to 30% of neutral salts, such as sodium sulfate.

Liquid assets include, for example
5 to 30%, preferably 8 to 25%, of the nonionic surfactant mixture according to the invention,
0 to 20%, preferably 2 to 15% of the aforementioned anionic surfactants,
0 to 10% of the aforementioned nonionic alcohol ethoxylates,
0.1 to 4%, preferably 0.2 to 2% of the aforementioned polyphosphonates,
0 to 2% of optical brighteners,
Balance water, organic solvents and hydrotropes.

Examples

The properties of nonylphenol-10 EO are compared with a surfactant mixture according to the invention “product A”. This "product A" according to the invention has the following composition:
average number of PO groups 1.2
average number of EO groups 6.4
C₈ = 1%
C₁₀ = 82%
C₁₂ = 10%
C₁₄ = 7%
C₁₅₋₁₆ = less than 0.1%
(Alkyl groups linear, saturated, primary OH group).

The comparison of the product properties was carried out according to the following criteria:
Cold cloud point (DIN 51 583)
Pour point (DIN 51 583) (English: pour point)
Immersion network capacity (DIN 53 901)
Determination of the surface tension (DIN 53 914)
Turbidity temperature (1% in deionized water) (DIN 53 917)
Determination of washing power

Determination of washing power

A detergent formulation of the following composition was used, which contains 3% nonylphenol + 10 EO (NP-10) and was replaced by product A. The ethoxylated C₁₂-C₁₄ amine + 2 EO was a product made from coconut fatty acids.

Test conditions

Washing machine with drum arranged horizontally (Miele U 433); Soaking program; 60 ° C; Concentration 5 g / l; Water hardness 16 ° dH; 3 rinsing and spinning cycles; Textile samples made of cotton (B), polyester (PE) and blended fabrics made of polyester-cotton (PE / B), each soiled with a dust-skin fat combination; 0.3 kg test fabric and 3 kg clean filling laundry; photometric evaluation

In a second series of experiments, woolen strands soiled with dust and skin oil were washed at 30 ° C. and a detergent concentration of 1.8 g / l of a detergent of the composition below.

With regard to their washing power, the agents according to the invention are able to replace the ethoxylated nonylphenol without any appreciable loss of activity. The combination according to Examples 2 and 4 is superior to the comparative product.

Biodegradability

In the modified OECD screening test, product A according to the invention achieved a carbon breakdown of over 70% and are therefore considered to be easily biodegradable. Nonylphenol with 9 EO or 10 EO does not reach this value. According to the criteria of the "Ordinance on the Degradability of Anionic and Nonionic Substances in Washing and Cleaning Agents" of January 30, 1977, the degradability was over 80% (found value over 96%).

Examples 5 to 7

The following experiments document that even small additions of the product according to the invention as an additive to detergent formulations known per se bring about a significant increase in washing power and outperform known washing power boosters (alkoxylated alkylamines) in this regard.

A I:

Staub/Hautfett auf Baumwolle (Standardgewebe des Wäscherei-Forschungsinstituts, Krefeld)

A II:

Staub/Hautfett auf veredelter Baumwolle

A III:

Staub/Hautfett auf 1:1 Mischgewebe aus veredelter Baumwolle und Polyester

A IV:

Staub/Hautfett auf Polyester

A V:

Staub/Hautfett auf Wolle

A VI:

Lippenstift auf A III-Gewebe

The tests were carried out in the machine used in Example 1 and tested on the following series of soiling:

AI:

Dust / skin fat on cotton (standard fabric of the laundry research institute, Krefeld)

A II:

Dust / skin oil on refined cotton

A III:

Dust / skin fat on 1: 1 blended fabric made from refined cotton and polyester

A IV:

Dust / skin fat on polyester

AV:

Dust / grease on wool

A VI:

Lipstick on A III fabric

Washing conditions (soaking program without prewash)

Example 5:

Normal program, 60 ° C, liquor ratio (kg of laundry to liter of water) = 1: 5.6, dosage 4.4 g / l

Example 6:

Easy care program, 40 ° C, liquor ratio 1:25, dosage 4.4 g / l

Example 7:

Delicates program, 40 ° C, liquor ratio 1:25, dosage 4.4 g / l

In the comparative experiments (index a, b) NP10 = nonylphenol and KA-2 EO = coconut amine + 2 EO (coconut alkyl = 2% C₁₀, 56% C₁₂, 22 C₁₄, 9% C₁₆, 11% C₁₈) were used. TA-5/10 EO is a 1: 1 mixture of C₁₆₋₁₈ tallow alcohol with 5 EO and 10 EO, C₁₂-ABS is Na-dodecylbenzenesulfonate (C₁₁₋₁₃-alkyl), the soaps are sodium soaps, STP is sodium tripolyphosphate, Aa-Ma-Cop is a 2: 1 acrylic acid-maleic acid copolymer Na salt (MW = 70,000).

The results are summarized in Table 1. They document the improved washing power of the products compared to NP10 and the increased washing power boost compared to coconut amine + 2 EO.

Examples 8 and 9

All-purpose cleaners of the following composition were manufactured and their cleaning effect was tested in the usual concentration for this product category.

Test conditions

The cleaning ability was determined according to the quality standards of the industrial association cleaning and care products, published in soaps, oils, fats, waxes. 108 , No. 16, p. 527 (1982).

To test the cleaning effect, the cleaning agent to be tested was placed in a 1% aqueous solution on an artificially soiled PVC plastic surface. A mixture of carbon black, machine oil, triglyceride of saturated fatty acids and low-boiling aliphatic hydrocarbon was used as artificial soiling. The test area of 26 x 28 cm was evenly coated with 2 g of the artificial soiling with the aid of a surface coater.

A plastic sponge was impregnated with 20 ml of the detergent solution to be tested and moved mechanically on the test surface. After 6 wiping movements, the cleaned test area was kept under running water and the loose dirt was removed. The cleaning effect, d. H. the whiteness of the plastic surface cleaned in this way was measured using an LF 90 photoelectric colorimeter (Dr. B. Lange). The clean white plastic surface served as the white standard.

Since the measurement of the clean surface was set to 100% and the soiled area was displayed with 0, the read values for the cleaned plastic areas were to be equated with the percentage cleaning ability (% RV).

The results show that NP10 is only slightly superior to the agents according to the invention only in formulations with a high surfactant content, but only scarcely achieves their cleaning effect when used sparingly.

Examples 10 and 11

Liquid abrasives of the composition listed below were produced and tested for their cleaning effect. The test procedure was identical to that used for testing all-purpose cleaners. Since liquid abrasives are used, in addition to the above-mentioned test dirt, which mainly contains fat, a test dirt which is predominantly containing pigments is more difficult to remove used. The latter consisted of soot, kaolin, calcium carbonate, petroleum jelly and low-boiling aliphatic hydrocarbon.

The results show that the agents according to the invention are almost equivalent to the comparison product compared to grease soiling, but are superior to pigment soiling.

Claims (5)

1. Surfactant mixtures liquid at room temperature based on polyalkoxylated alcohols, characterized in that they consist of a straight-chain ether alcohol or of an ether alcohol methyl-branched in the 2-position corresponding to the following general formula
   
   
   
           R - O - (PO)₁₋₂ - (EO)₆₋₈ - H
   
   
   
   in which PO represents the residue of the ring-opened propylene oxide and EO represents the residue of the ring-opened ethylene oxide, characterized in that the alkyl or alkenyl radicals R have the following composition: C₈ = 0 to 5% by weight, C₉₋₁₀ = 75 to 90% by weight, C₁₁₋₁₂ = 5 to 15% by weight, C₁₃₋₁₄ = 4 to 10% by weight and C₁₅₋₁₆ = 0 to 3% by weight.
2. A surfactant mixture as claimed in claim 1, characterized in that R is a linear alkyl radical having the following composition: C₈ = 0 to 2% by weight, C₁₀ = 80 to 84% by weight, C₁₂ = 7 to 12% by weight, C₁₄ = 6 to 8% by weight and C₁₅₋₁₆ = 0 to 1% by weight.
3. Detergents and cleaning preparations containing the surfactant mixture claimed in claims 1 and 2, characterized in that they are free from alkoxylated alkylphenols.
4. Detergents and cleaning preparations as claimed in claim 3, in which the surfactant mixture is present in combination with ethoxylated alkyl amines containing 10 to 18 carbon atoms in the alkyl chain.
5. Detergents and cleaning preparations as claimed in claim 4, in which the alkoxylated alkyl amine contains 2 to 3 EO groups.