Aqueous laundry softening agent with high zeta potential

Translation of description of equivalent WO 9747716 A2

Aqueous fabric softeners with high zeta potential

The present invention relates to aqueous dispersions containing fatty substances and emulsifiers, as fabric softeners, which are characterized by a high positive zeta potential of the dispersion.

Textile treatment agents that have a softening effect on clothes are wohlbe¬ known. You are einge¬ usually in the final rinse of a washing machine sets and give the laundry a pleasant, soft feel, since they exhibit a pronounced sorption on different fiber surfaces. The assignment of the fiber with the long-chain molecules leads to a sliding effect between the fibers and thus prevents water or dry rigidity, which is responsible for the hard touch of the fabric. A possible adsorption for the rearing of weichma¬ relevant Wrkstoffen is the electrostatic attraction between the, for example by washing alkali negatively charged fiber surface and positively charged softener particles. Statements about the magnitude and sign of the surface charge can be obtained by measuring the so-called zeta potential, which the electroplating voltage at the diffuse electrochemical double layer at the interface zwi¬ tween the surface of a solid, for example, a dispersed plasticizer, and a liquid, for example, the wash liquor, describes.

Usually, as a fabric softening active water-insoluble quaternary ammonium compounds containing two long chain alkyl or alkenyl, verwen¬ det. Frequently used connections are aryldimethylammoniumchlorid Ditalgdimethylammmoniumchlorid or Diste-. However, since such compounds are considered to be ecologically harmful, increasingly Difettsäuretrialkanolaminestersalze be used, which are obtained, by reacting a trialkanolamine with technical fatty acids and subsequent Quatemie- tion, such as methyl-N- (2-hydroxyethyl) -N, N-di ( talgacyl- oxyethyl) ammonium methosulfate.

Usually, fabric softeners are available in the form of aqueous dispersions. This raises the problem that with increasing proportion of active substances, the viscosity of the dispersion increases, which complicates the handling by the consumer, and further terhin the stability of such products is not sufficient. Such problems to the überwin¬ was beat for example in EP 043 622 B1, an aqueous stable dispersion vorge containing 8 to 22 wt .-% of a water-insoluble cationic fabric softener and a viscosity control system, containing 0.5 to 6 wt .-% C₁₀,₂₄- Hydrocarbons, Cιo-₂₄Fatty acids or Cιo-₂₄Fatty acid esters of fatty acids with short-chain alcohols or Cιo-₂4-fatty alcohols and 0.05 to 1 wt .-% of a water-soluble cationic polymer. The addition of polymers for viscosity regulation often leads but to a reduced performance of the fabric softener. Means without polymeric viscosity modifiers are described in DE 36 02 089 C2. The compositions contain in addition to customary kationi¬'s fabric softeners a fatty alcohol having 10 to 24 carbon atoms, wherein the weight ratio between the cationic softeners to fatty alcohols is between 3.5: is 1: 1 and 6. FIG. Emulsifiers ethoxylated amines. From German patent application 42 32 448 A1 solid agents are known, the quaternary Difettsäuretrialkano- laminestersalze, and a hydroxy compound selected from the group of Fettalko¬ hole, Fettalkoholpolyglykolether, polyol fatty acid and carbohydrates and for the manufacture of liquid aqueous softening compositions (with 1 to 50 wt .-% of active substance) are. The weight ratio of quaternary ester amine salt and hydroxy compound is between 9: 1 range: 1 and. 1 A disadvantage of this means, however, that relatively high amounts are used in environmentally unsatisfactory, nitrogenous compounds. By contrast, in EP 497 769 A2 are acidic, proposed aqueous fabric softener containing a softening component pen- taerythrithester in quantities of 1 to 25 wt .-%, and from 0.1 to 10 wt .-% of a nonionic emulsifier and so are ecologically harmless are. The features disclosed in this specification means may also contain up to 0.5 wt .-% quaternized Ammoniumver¬ bonds. However, such compositions have only zeta potentials of not more than +27 mV at pH =. 7

Despite these different approaches, stable, easily manageable Textilweichma- produce cherdispersionen, there is still the need the existing For¬ formulations in performance and environmental governance to improve. The object of the invention Er¬ was therefore stable aqueous fabric softener dispersions based weitge¬ based biodegradable ingredients with beneficial ecotoxicological Eigenschaf¬ th produce. It has now been found that combinations of biodegradable, was¬ serunlöslicher fatty substances with emulsifiers in certain proportions just then leads to efficient means when the zeta potential of the aqueous dispersions exceeds a certain value.

The invention therefore Fabric softeners in the form of an aqueous dispersion of a Dis¬ Avivagekomponente, wherein the Avivagekomponente, based on the part by weight of the fabric conditioning composition, of 0.5 to 20 wt .-% of at least one nonionic fatty substance and from 0.2 to 10 percent by .-% of a water soluble and / or water-insoluble katio¬ African emulsifier, and 0 to 10 wt .-% of a nonionic emulsifier, wherein the weight ratio between lipid and emulsifiers is between 10: 1 and 0.5: 1, and the proviso that the zeta potential of the aqueous dispersion at a pH of 7 and a temperature of 25 ° C is at least + 30 mV.

To obtain funds with the desired zeta potentials, it is initially advantageous to fatty substance with an appropriate amount of nonionic emulsifier to disperse completely in water and then ein¬ noted by adding the cationic emulsifier, the zeta potential.

The measurement of the zeta potential is a common method for the characterization of solid / liquid dispersions (RJ Hunter, Zeta Potential in Colloid Science, pages 150 to 162, Academic Press, New York 1981). Dispersed particles can, for example, by adsorption of ions on their surface, electrically charged. thereby forming an electric double layer, which is firmly connected with the particles and lead to an apparent increase in volume at the surface of the electrically charged particles. This solid layer is covered by a movable and diffuse lonenschicht. The potential on the particle surface Ψo now falls within the fixed lonenschicht with the thickness δ line¬ ar to the value ψ_δ from to go back in the diffuse layer approximately exponentially up to 0. The potential difference between the inner fixed lonenschicht ψ_δ and the point within the diffuse lonenschicht, in which the potential to 1 / e ^• ψ_δ zurückge¬ is addressed, is called zeta potential.

The zeta potential can be determined from the migration direction and speed of the dispersed particles th in the electric field directly (M. Hoffmann, H. Kromer, R. Kuhn, polymer analysis II, Georg Thieme Verlag, Stuttgart 1977, pages 260-264) where chosen as a basis the following relationship: f -π- v η ζ =

E-ε ζ = zeta potential (in mV) ε = dielectric constant of the dispersant v = electrophoretic migration velocity (in cm / s) η = viscosity of the dispersing agent (Poise, 1 poise = 0.1 Pa • s)

E = field strength (in mV) f = numerical factor (friction factor), which depends on the shape of the particles, their conductivity and the size of the particles compared to the thickness of the diffuse double layer

The measurement of the rate of migration is carried out, depending on the size of the relevant untersu¬ particles either by means of light-microscopic observation or, particularly for smaller particles, by means of laser correlation spectroscopy (W. Demtröder, Laserspek¬ spectroscopy: Fundamentals and Techniques, 2nd Edition, Springer-Verlag, Berlin, 1991, section 12.7 to 12.7.2).

The high positive zeta potential of the dispersion causes the dispersed Teil¬ chen correctly attach to the negatively charged fibers and through the voll¬ permanent enclosure of the fibers with hydrophobic, long-chain alkyl radicals a good softening effect. Here agents are particularly suitable which as it exists over a broad pH range, in the wash liquor, have the highest possible zeta potential. Particularly preferred are dispersions of the invention which have not only at a pH of 7, a zeta potential of at least + 30 mV, but which is also at a pH value of 8, which is often sufficient er¬ in the wash liquor during the wash cycle, yet at least a zeta potential of +25 mV show (temperature of 25 ° C). Particularly preferred are dispersions which show their zeta potential at a temperature of 25 "C and a pH value of 7 at least + 40 mV.

The inventive dispersions contain at least one fatty substance in quantities zwi¬ 0.5 and 20 wt .-%, preferably between 2 and 12 wt .-% and in particular between 4 and 6 wt .-%, based on the total amount of the agent, as well as the kationi¬ rule emulsifier in amounts between 0.2 and 10 wt .-%, preferably between 0.3 and 8 wt .-%, in particular between 0.4 and 6 wt .-%, and optionally an emulsifier in amounts's nichtioni¬ up to 10 wt .-%. It is essential that the Gewichtsver¬ ratio between lipid and emulsifier is between 10: 1 and 0.5: 1, and the amounts of the ingredients are adjusted so that the zeta potential of the dispersion at a pH value of 7 and 25 ° C at least + 30 mV. Only then is it possible that in raise aus¬ sufficient quantities softening substances to the textile fibers to a achieve good plasticizing effect. Particularly preferred dispersions in this case have a weight ratio between lipid and emulsifiers is between 1: 1 and 8: 1, and especially between 2: 1 and 6: 1.

Fatty substances are understood at normal temperature (20 ° C) solid fats, fatty alcohols, waxes and hydrocarbons within these applications. Given to Example include for example hydrogenated fats and oils of animal and vegetable origin, and nichtzy¬ clic, branched and unbranched hydrocarbons with 12 to 30 carbon atoms. Examples of such compounds are tetradecane, hexadecane, octadecane and octadecene. Preferably, the fatty substances from the group of fatty acid esters of Fettsäu¬ are acids containing 12 to 22 carbon atoms with mono- or polyhydric alcohols having 1 to 22 carbon atoms, and selected fatty acids or fatty alcohols having 12 to 22 carbon atoms and mixtures of these substances. These are in particular mono- or esters of fatty acids with pentaerythritol, monoesters and diesters of -C₂-₁cerin 8-fatty acids Gly or monoesters of -C₂.ιβ acids with -C₂-i_8thFatty alcohols preferred.

Examples of such compounds are lauric, myristic, palmitic or stearic acid, and methyl and ethyl esters of these acids. As fatty alcohols deca nol, dodecanol, tetradecanol, pentadecanol, hexadecanol or octadecanol and Mi¬ mixtures of these alcohols are used for example. Examples of preferably used fatty substances are technical or Pentaerytrithdistearinsäureester Glycerinmonostearinsäureester and industrial fatty alcohols.

Cationic emulsifiers are understood compounds in the context of the present application Verbin¬ selected from the group of quaternary ammonium compounds of formulas (I) and (II),

R - X^"

<img id="imgf000007_0001" he="27" wi="131" file="imgf000007_0001.tif" img-format="tif" img-content="drawing" orientation="portrait" inline="no" />

wherein R is an acyclic alkyl radical having 12 to 24 carbon atoms, R¹ for a ge saturated C₁C4 alkyl or hydroxyalkyl group, R² either equal to R or R¹ is and COR³ is an aliphatic acyl group containing 12 to 22 carbon atoms with 0, 1, 2 or 3 double bonds and R⁴ is H or OH, wherein n is 1, 2 or 3 and X is either a halide, methosulfate, Metophosphat- or phosphate is, and mixtures of these compounds. Particularly preferred compounds, the alkyl radicals having 16 to 18 carbon atoms.

Examples of cationic surfactants of formula (I) are didecyldimethylammonium chloride, ditallow dimethyl ammonium chloride or dihexadecylammonium. Examples of compounds of the formula (II) are methyl-N- (2-hydroxyethyl) -N, N-di (tallow acyl-oxyethyl) ammonium methosulfate, bis- (palmitoyl) -ethyl hydroxyethyl methyl ammonium methosulfate or methyl N, N-bis (acyloxyethyl) -N- (2-hydroxyethyl) ammonium methosulfate. In addition to the compounds of formulas (I) and (II), short-chain, water-soluble, quaternary ammonium compounds can be used, such as trihydroxyethyl-methyl-ammonium methosulfate or cetyl trimethyl ammonium chloride. Also protonated Alkylaminverbindun- gen having softening effect, as well as the non-quaternary, protonated precursors of the cationic emulsifiers are also suitable.

If quaternized compounds of formula (II) which have unsaturated alkyl chains, the Aclygruppen are preferred which have their corresponding fatty acids have an iodine value of 5 and 25 and preferably between 10 and 25 and especially between 15 and 20 and which have a cis / trans isomer ratio (in wt .-%) of 30: 70, preferably greater than 50: 50 and in particular greater than 70: 30 have.

Besides the quaternary compounds described above, other known compounds can be used, such as quaternary Imidazoliniumverbindun- gen of formula (III)

<img id="imgf000008_0001" he="45" wi="90" file="imgf000008_0001.tif" img-format="tif" img-content="drawing" orientation="portrait" inline="no" /> where R⁵ a saturated alkyl radical having 12 to 18 carbon atoms, R⁶ alkyl of 1 to 4 carbon atoms or H and Z is an NH group or oxygen tet bedeu¬ and A is an anion.

Other suitable quaternary compounds are described by formula (IV), + (R⁷)₃N- (CH₂)_n- CH OOCR^8th

CH_?- OOCR^8th

(IV) wherein R⁷ each independently selected for a C ^ alkyl, alkenyl or hydroxyalkyl group, R^8th each independently selected a C_8-28 represents alkyl group, and n is a number between 0 and 5. FIG.

As part of this application are nonionic emulsifiers compounds which, in men from the group of alkoxylated fatty acids having 12 to 22 Kohlenstoffato¬, the alkoxylated fatty acid esters of fatty acids having 12 to 22 carbon atoms with alcohols having 1 to 10 carbon atoms and the alkoxylated fatty alcohols containing 12 to 22 carbon atoms, which comprise the alkoxylated compounds HLB values ​​between 3 and 20 as well as fatty acid amides and monoalkanolamides from -C₂-C₂₂Fatty acids with amines or Alkanotaminen having 1 to 9 carbon atoms, and alkyl glycosides or glucamides, are selected. Preferred are alkoxylated compounds having an HLB value of between 3 and 20 preferably between 8 and 14. Example of nonionic emulsifiers according to the invention are C₁₂-₁8- fatty alcohols with 7 EO, cetyl / stearyl alcohol with 20 EO or fatty acid. As alkyl glycosides, compounds of general formula RO (G)_x used, in which R is a primary linear or methyl-branched, in particular in the 2 position vorzugswei¬ aliphatic radical having 8 to 22, se 12 to 18 carbon atoms and G is the symbol which represents a glycose unit having 5 or 6 C- atoms, preferably for glucose. The Oiigomerisierungsgrad x, which indicates the distribution of monoglycosides and oligoglycosides, is any number zwi¬ 1 and 10; preferably between 1.2 to 1.4.

As glucamides fatty acid-N-alkyl are preferred as they are represented by the formula (IV),

10

OH OH OH

R CO-N-CH -CH-CH-CH-CH-CH OH (IV)

2 2

OH 10 9 wherein R is hydrogen or an alkyl group and R CO is the acyl radical of caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, Palmolein¬ acid, stearic acid, isostearic acid, oleic acid, elaidic acid, petroselinic acid, linoleic acid, linolenic acid, arachidic acid , Gadoleinsäure, behenic or erucic beziehungswei¬ se technical mixtures thereof. Fatty acid-N-alkyl glucamides (IV) obtained by reductive amination of glucose with methylamine and subsequent acylation with lauric acid or C₁₂/ ι₄Coconut oil fatty acid or a corresponding derivative are particularly preferred.

In addition to the above ingredients, the agents may also contain other additives commonly used in fabric softeners substances. These include or¬ ganic solvent such as ethanol or isopropyl alcohol, fungicides, enzymes beispiels¬ as cellulase, dyes, optical brighteners, lecithin, UV absorbers, Konservie¬ insurance agents, soil repellents, pearlescent agents or fragrances. Furthermore, the compositions may comprise electrolytes, preferably sodium, magnesium or calcium chloride, as well as pH adjusting agents such as organic and inorganic acids.

The dispersions of the invention are produced in a conventional manner by mixing the ingredients with the necessary amount of water, then heated to a temperature of 60 ° C and 5 to 30 minutes keitsmischer mixed in a Hochgeschwindig¬. The thus obtained aqueous Weispülerdispersionen have a pH value between 2 and 7, preferably between 3 and 6.

Examples

The mentioned in Examples 1 to 8 aqueous dispersions were prepared by the respective fatty substances presented with the emulsifiers and water and heated with thorough mixing at 80 ° C. After the raw materials homogeneously dispersed wa¬ reindeer by the addition of cationic emulsifier with thorough mixing. The Dis¬ was cooled dispersion with gentle stirring at 30 ° C. and then the remaining ingredients, such as perfume oils.

The zeta potentials of the aqueous dispersions and the assessment of hand giving Wir¬ kung can be taken from Table 1 below.

The determination of the handle-forming effect was tested on pre-washed Frottiergewebetü¬ holes that have been equipped with the means to be examined and then dried in the room air. The test fabrics were added in a glass tumbler with about untersu¬ relevant agents (concentration 15 g / kg dry washing, water hardness 16 ° d, Flottenver¬ ratio 1: 5) for 5 minutes, the drum was placed in reversing movements. The towels were of a test panel (5 people) shares reached technically beur¬. Lingerie grip was as an average of the three tests in grades ange¬ give (0 = hard, 6 = soft), which handle scores were rated from 3.8 as well.

The measurement of zeta potential was carried out using a Malvern Zetazisers^® 3 at a temperature of 25 ° C. For the determination of the zeta potential, the respective dispersion with 0.001 molar potassium chloride solution was 1: 400 diluted and then the pH with hydrochloric acid or sodium hydroxide to the desired value set. The values ​​given are mean values ​​of 5 measurements.

The dispersions of the invention shown in a low content of quaternary N-containing compounds, good hand-giving properties that are associated with the performance marktüb¬ Licher plasticizer comparable containing containing as Avivagekomponente only cationic N- salts.

For comparison, the two non-inventive examples 7 and 8 and a commercially available plasticizer were 9 investigated on the basis of a known quaternary ester amine salt. Although 7 has a combination of lipid and cationic and nichtioni¬ Shem emulsifier, the zeta potential at pH = 7 lies at + 30 mV. 8 illustrates a combination of a cationic and two non-ionic emulsifiers, without an inventive lipid was added. The example 10 shows that the combination tion of the ingredients according to the invention does not necessarily lead to dispersions with a high zeta potential.

For all sample compositions that the missing amounts to 100 wt .-% water and minor ingredients (electrolytes, perfume oil, auxiliaries etc.) mean.

example 1

1.26 wt .-% C16₁8 fatty alcohol

0.70 wt .-% methyl laurate + 12 EO

0.54 wt .-% bis (palmytoyl) ethyl hydroxyethyl methyl ammonium methosulfate

example 2

5.00 wt .-% Di-Ciβ-iβ-alkyl pentaerythritol

0.36 wt .-% Trimethyl hexadecyl ammonium chloride

0.30 wt .-% C_12-ι₆Fatty alcohol-1, 4-glycoside

example 3

7.70 wt .-% di-C_16-i_8thalkyl pentaerythritol

0.82 wt .-% tallow amine + 2 EO adduct (commercial product Genamin^® T 020, Fa. Hoechst)

1:25 wt .-% tris (oligooxyethyl) -alkylammoniumphosphat

example 4

5.00 wt .-% Di--C₆.i8-alkyl-ρentaerythritester

1, 08 wt .-% methyl-N- (2-hydroxyethyl) -N, N-di (talgacyloxyethyl) ammonium methosulfate

0.56 wt .-% methyl laurate + 12 EO

example 5

4.00 wt .-% C₁₆-ιβ fatty alcohol

1, 35 wt .-% methyl-N- (2-hydroxyethyl) -N, N-di (talgacyloxyethyl) ammonium methosulfate

0.75 wt .-% methyl laurate + 12 EO

example 6

4.00 wt .-% glycerol mono-di-palmitate

1, 35 wt .-% methyl-N- (2-hydroxyethyl) -N, N-di (talgacyloxyethyl) ammonium methosulfate

0.90 wt .-% methyl laurate + 12 EO

example 7

5.00 wt .-% di-C ₁₆-₁8-alkyl-pentaerythritol

0.17 wt .-% methyl-N, N-bis (acyloxyethyl) -N- (2-hydroxyethyl) ammonium methosulfate

1:26 wt .-% methyl laurate +12 EO example 8

2.50 wt .-% C₁₂.i6 fatty alcohol-1, 4-glycoside

0.19 wt .-% methyl-N, N-bis (acyloxyethyl) -N- (2-hydroxyethyl) ammonium methosulfate

0.84 wt .-% methyl laurate +12 EO

example 9

4.50 wt .-% methyl-N- (2-hydroxyethyl) -N, N-di (talgacyloxyethyl) ammonium methosulfate

example 10

5.00 wt .-% Di-Ciβ-iβ-alkyl pentaerythritol

1.28 wt .-% -C₂-i_8thFatty alcohol +7 EO

0.82 wt .-% tallow-2 EO adduct (Genamin^® T 020, Fa. Hoechst)

0.50 wt .-% methyl-N- (2-hydroxyethyl) -N, N-di (talgacyloxyethyl) ammonium methosulfate

Table 1

Zeta potential [mV]

Composition pH = 7 pH = 8 Note

1 52 52 4,7

2 41 38 3.9

3 42 30 4.7

4 45 45 4.8

5 52 41 4.7

6 52 44 4.3

7 24 27 2.6

8-35 - 32 1 5

9 65 65 5.0

10 27 23 3.5