CA2103578A1 - Free-flowing pearlescent concentrate - Google Patents

Abstract

Lustrous concentrates containing (A) 15-40 % wt. lustrous components, (B) 5-55 % wt. emulsifiers and (C) 15-40 % wt. low-molecular polyvalent alcohols can be poured or pumped and can be stored for long periods without the addition of preserving agents.

Description

`~ 21 ~3~7~

A free-flowing pearle-Qcent concentrate This invention relates to a pearlescent concen-trate in the form of a free-flowing or pumpable, aqueous dispersion containing 15 to 40% by weight pearlescing components.
Aqueous preparations of surfactants and cosmetic preparations can be given a pearlescent, aesthetically attractive appearance by incorporation of substances which, after cooling, precipitate in the form of fine nacreous-looking crystals and remain dispersed in the preparations. Suitable so-called pearlescers are, for example, the monoesters, diesters and optionally tri-esters of ethylene glycol, propylene glycol and oligo-meric alkylene glycols of this type or glycerol with C1422 fatty acids, fatty acids and also monoalkanolamides of fatty acids.
It is also known that the pearlescers mentioned form stable dispersions in water or in aqueous surfac-tant solutions and that the concentrated pearlescent dispersions obtained in this way can be added without heating to the preparations to be given a pearlescent appearance, so that there is no longer any need for the heating and cooling otherwise necessary for incorpora-tion to form the pearlescent crystals.
Pearlescent concentrates based on the pearlescers mentioned above are known, for example, from DE-A-16 69 152, from JP-S6/71021 (Chem. Abstr. 95/156360), from DE-A-34 11 328, DE-A-35 19 08~ and DE-A-38 43 5~2.
One problem affecting the production and use of pearlescent concentrates concerns their flowability and pumpability. Flowability and pumpability are often seriously restricted, above all at high concentrations of pearlescing components, or the mixtures present can-21;33~73 Wo 92/13512 2 PCT/EP92/00179 not flow at all or cannot even be pumped by conventional pumping equipment.
Accordingly, it was proposed in German patent application D~ 38 ~3 572 to reduce the viscosity of pearlescent concentrates by addition of small quantities of low molecular weight, polyhydric alcohols and thus to establish flowability and pumpability.
In addition, known pearlescent concentrates are provided with preservatives, such as for example organic acids (formic acid, benzoic acid, salicylic acid, sorbic acid), formaldehyde, isothiazolinones, PHB esters or 1,3-dioxanes for protection against bacterial and fungal contamination.
However, preservatives are known from dermatolog-ical st-ldies to cause a number of skin irritations and complaints. Accordingly, preservative-free personal hygiene preparations and cosmetics have very recently come increasingly onto the mar~et. To enable products such as these to be given the asethetically attractive appearance required by the consumer through the use of pearlescent concentrates, there is thus a need for pearlescent concentrates which can be formulated without preservatives. However, the absence of preservatives should not adversely affect the microbiological stabili-ty or other properties of these concentrates.
It has now been found that preservative-free pearlescent concentrates equivalent to known pearlescent concentrates in their stability and in their flowability and pumpability can be obtained by addition of relative-ly large quantities of low molecular weight polyhydricalcohols.
Accordingly, the present invention relates to a pearlescent concentrate in the form of a free-flowing, aqueous dispersion which is characterized by a content of 21~3~v73 Wo 92/13512 3 PCT/EP92/00179 (A) 15 to 40~ by weight pearlescing components, (B) 5 to 55% by weight emulsifiers and (C) 15 to 40% by weight low molecular weight, poly-hydric alcohols.

Particularly advantageous properties are exhi-bited by pearlescent concentrates containing (A) 20 to 30% by weight pearlescing components, (B) 10 to 35% by weight emulsifiers and (C) 20 to 40% by weight low molecular weight, poly-hydric alcohols.

Pearlescing components are understood to be fusible fats or waxes which crystallize out in the form of fine, pearlescing substances on cooling of their aqueous solutions or emulsions at temperatures in the range from about 30 to 90C.
These fusible fats or waxes include (Al) esters corresponding to formula (I) R - (CnH2n)~ - OR (I) in which Rl is a linear C1422 fatty acyl group, R2 is hydrogen or a group R1, n = 2 or 3 and x is a number of 1 to 4, (A2) monoalkanolamides corresponding to general formula (II) R3 - CO - NH - X (II) in which R3 is an alkyl group containing 8 to 22 and, more especially, 8 to 18 carbon atoms and X
is a -CH2-CHz-OH group, a -CH2-CH2-CH2-OH group or 21 ~3~73 wo 92/13512 4 PCT/EP92/00179 a -C(CH3)2-OH group, (A3) linear, saturated C1~22 fatty acids and (A4) B-ketosulfones corresponding to general formula (III):

Rs R4 - CO - CH - SO2 - CH2 - R6 (III) .

in which R4 is a C112l alkyl or alkenyl group, R5 and ~6 are hydrogen atoms or together represent an ethylene group which forms a tetrahydrothiophene dioxide ring with the group between R5 and R6 and (A5) mono-, di- and triesters of glycerol with linear saturated C1~22 fatty acids.

Suitable esters (A1) corresponding to the general formula Rl(O~H2n)~OR2 are, for example, the monoesters and diesters of ethylene glycol and propylene glycol with higher fatty acids, for example with palmitic acid, stearic acid or behenic acid, or the diesters of diethy-lene glycol or triethylene glycol with such fatty acids.
Also suitable are mixtures of monoesters and diesters of the glycols mentioned with fatty acid mixtures, for example with hydrogenated tallow fatty acid, palm oil fatty acid or with the saturated C1~18 fatty acid frac-tion of tallow fatty acid. The ethylene glycol mono-ester and/or diester of palmitic and/or stearic acid is particularly suitable.
Preferred monoalkanolamides (A2) are the mono-ethanolamides. These compounds may contain individual alkyl radicals. However, it is standard practice to produce the alkanolamides from fa~ty acid mixtures from natural sources, for example coconut oil fatty acids, so that corresponding mixtures are present in regard to the alkyl radicals.

21~3~73 ~o 92/13512 5 PCT/EP92/00~79 Suitable linear fatty acids (A3) are, for ex-ample, palmitic acid, stearic acid, arachic acid or behenic acid, although it is also possible to use technical fatty acid cuts consisting entirely or predom-inantly of C162z fatty acids, for example palmitic/
stearic acid fractions of the type obtained from tallow fatty acid or palm oil fatty acid by separation of the fatty acids liquid at +5 C or palmitic/stearic acid fractions of the type obtainable by hydrogenation of tallow fatty acid or palm oil fatty acid.
The ~-ketosulfones (A4) of general formula (III) have the advantage over the known ethylene glycol monoesters and diesters that the pearlescence of the preparations shows higher heat stability, i.e. the preparations retain their pearlescence for several hours on heating to temperatures above 50 C and, in some cases, to temperatures above 70-C. Further information on the B-ketosulfones mentioned can be found in German patent application 35 08 051.
The esters of glycerol (A5) suitable for use in accordance with the teaching of the invention include the mono-, di- and in particular triesters with myristic acid, palmitic acid, stearic acid and behenic acid and with mixtures of these fatty acids.
Fatty alcohols containing at least 20 C atoms and, in particular, 20 to 30 C atoms may also be used as pearlescing components.
The pearlescent concentrates according to the invention may exclusively comprise representatives of one of these classes of compounds and also mixtures of representatives of several of these classes of com-pounds.
Preferred pearlescing components are representa-tives of classes (Al) to (A3).
However, fatty acid mono- or dialkanolamides, - 2 1 ~ 3 ~ ~ ~
~o 92/13512 6 PCT/EP92/00179 i.e. pearlescing components of group (A2), and deriva-tives thereof have recently been suspected of partici-pating in the formation of nitroamines. Accordingly, it may be desirable to formulate cosmetic preparations without such alkanolamines and alkanolamine derivatives.
For this reason, compounds of classes (A1) and (A3) can be particularly preferred pearlescing components.
Pearlescent concentrates in which at least 70% by weight and more especially at least 9o~ by weight of the pearlescing components consist of ethylene qlycol distearate are particularly preferred.
Emulsifiers (B) are ionic or nonionic surface-active compounds distinguished by a lipophilic, prefer-ably linear, alkyl or alkenyl group and at least one hydrophilic group. The hydrophilic group may be both an ionic group and also a nonionic group.
Suitable anionic emulsifiers (B) suitable for use in accordance with the invention are, for example, alkyl sulfates and alkyl polyethylene glycol ether sulfates containing 8 to 22 C atoms in the alkyl chain and 1 to 15 and more particularly 1 to 6 ethylene glycol ether groups in the molecule which are used in the form of their alkali, magnesium, ammonium, mono-, di- or tri-alkanolammonium salts containing 2 to 3 C atoms in the alkanol group. Other suitable anionic surfactants are alkanesulfonates, ~-olefin sulfonates, ~-sulfofatty acid methyl esters, fatty alcohol (polyglycol ether) carboxy-lates, sulfosuccinic acid mono- and dialkyl esters, sul-fosuccinic acid ester salts, acyl isethionates, acyl taurides and acyl sarcosides containing 8 to 22 and more particularly 12 to 18 C atoms in the alkyl or acyl chain. Soaps may also be used as emulsifiers. This may ~e achieved, for example, by saponifying a small propor-tion, for example about 1 to 20% by weight, of the linear, saturated fatty acids by added alkali metal 21~3.78 ~O 92/13512 7 PC~/EP92/0017g hydroxide and thus converting it into an anionic emul-sifier.
Preferred anionic emulsifiers are the alkyl polyethylene glycol ether sulfates such as, for example, sodium lauryl polyglycol ether sulfate.
Suitable cationic emulsifiers (B) are quaternary ammonium surfactants, for example alkyl trimethyl ammonium chlorides and dialkyl dimethyl ammonium chlo-rides, for example cetyl trimethyl ammonium chloride, stearyl trimethyl ammonium chloride, distearyl dimethyl ammonium chloride, lauryl dimethyl ammonium chloride and lauryl dimethyl benzyl ammonium chloride, cetyl pyri-dinium chioride and tallow alkyl tris-(oligooxyalkyl)-ammonium phosphate.
Zwitterionic surfactants may also be used as the emulsifiers (B). Zwitterionic surfactants are surface-active compounds which contain at least one quaternary ammonium group and at least one -COO(~) or -SO3(-) group in the molecule. Particularly suitable zwitterionic surfactants are the so-called betaines, such as the N-alkyl-N,N-dimethyl ammonium glycinates, for example cocoalkyl dimethyl ammonium glycinate, N-acylamino-propyl-N,N-dimethyl ammonium glycinates, for example cocoacylaminopropyl dimethyl ammonium glycinate, and 2-alkyl-3-carboxymethyl-3-hydroxyethyl imidazolines containing 8 to 18 carbon atoms in the alkyl or acyl group and also cocoacylaminoethyl hydroxyethyl car-boxymethyl glycinate. The fatty acid amide derivative known by the CTFA name of cocoamidopropyl betaine is a preferred zwitterionic surfactant.
Other suitable emulsifiers (B) are ampholytic surfactants. Ampholytic surfactants are surface-active compounds which, in addition to a C8l8 alkyl or acyl group in the molecule, contain at least one free amino group and at least one -COOH or -SO3H group and are ` 21i33~7~
~o 92/13512 8 PC~/EP92/00179 capable of forming inner salts. Examples of suitable ampholytic surfactants are N-alkyl glycines, N-alkylpro-pionic acids, N-alkylaminobutyric acids, N-alkylimino-dipropionic acids, N-hydroxyethyl-N-alkylamidopropyl glycines, N-alkyltaurines, N-alkylsarcosines, 2-alkyl-aminopropionic acids and alkylaminoacetic acids contain-ing approximately 8 to 18 carbon atoms in the alkyl group. Particularly preferred ampholytic surfactants are N-cocoalkylaminopropionate, cocoacylaminoethylamine propionate and C~218 acyl sarcosine.
Finally, it is also possible to use nonionic emulsifiers (B) which contain, for example, a polyol group, a polyalkylene glycol ether group or a combina-tion of a polyol group and a polyglycol ether group as the hydrophilic group. Compounds such as these are, for example, (B1) adducts of 2 to 30 mol ethylene oxide and/or 0 to 5 mol propylene oxide with linear Ca22 fatty alcohols, with C1222 fatty acids and with alkyl phenols containing 8 to 15 carbon atoms in the alkyl group, (B2) C~222 fatty acid monoesters and diesters of adducts of 1 to 30 mol ethylene oxide with glycerol, (B3) glycerol monoesters and diesters and sorbitan monoesters and diesters of saturated and unsatu-rated Ca22 fatty acids and ethylene oxide adducts thereof, (B4) C822 alkyl mono- and -oligoglycosides and ethoxy-lated analogs thereof and (B5) adducts of 10 to 60 mol ethylene oxide with castor oil and hydrogenated castor oil.

Mixtures of compounds from several of these ` h~ 33~7d W0 92/13512 9 PCT/E~92/00179 classes are also suitable.
The adducts of ethylene oxide and/or propylene oxide with fatty alcohols, fatty acids, alkyl phenols, glycerol monoesters and diesters and sorbitan monoesters and diesters of fatty acids or with castor oil are known commercially available products. They are homolog mixtures of which the average degree of alkoxylation corresponds to the ratio between the quantities of ethylene oxide and/or propylene oxide and substrate with which the addition reaction is carried out.
C~222 fatty acid monoesters and diesters of adducts of ethylene oxide with glycerol are known from DB-PS 20 24 051 as refatting agents for cosmetic prepar-ations. C822 alkyl mono- and -oligoglycosides, their production and their use as surfactants are known, for example, from ~S-A 3,839,318, US-A 3,707,535, US-A

3,547,828, DE-A 19 43 689, DE-A 20 36 472 and DE-A 30 01 064 and from EP-A 77 167. They are prepared in particu-lar by reaction of glucose or oligosaccharides with primary C322 alcohols. So far as the glycoside residue is concerned, both monoglycosides, in which a cyclic sugar residue is attached to the fatty alcohol by a glycoside bond, and also oligomeric glycosides having a degree of oligomerization of up to, preferably, about 8 2S are suitable. Degrees of oligomerization of 1.4 and lower can be particularly preferred. The degree of oligomerization is a statistical mean value on which a homolog distribution typical of such technical products is based.
The compounds of group (Bl) are particularly preferred nonionic emulsifiers (~) for the purposes of the invention.
The compounds containing alkyl groups used as surfactants may be individual substances. However, it is generally preferred to use native vegetable and 21~ 7~
~o 92/13512 10 PCT/EP92/00179 animal starting materials in the production of these compounds, sc that mixtures having different alkyl chain lengths depending on the particular starting material used are obtained.
The surfactants which are adducts of ethylene and/or propylene oxide with fatty alcohols may be both products with a "normal" homolog distribution and products with a "narrow" homolog distribution. Products with a "normal" homolog distribution are understood to be mixtures of homologs which are obtained in the reaction of fatty alcohol and alkylene oxide using alkali metals, alkali metal hydroxides or alkali metal alcoholates as catalysts. By contrast, narrow homolog distributions are obtained when, for example, hydrotal-lS cites, alkaline earth metal salts of ether carboxylic acids, alkaline earth metal oxides, hydroxides or alcoholates are used as catalysts. The use of so-called "narrow-range" products can be preferred.
According to the teaching of the invention, the pearlescent concentrates may contain representatives of one or more of the surfactant classes mentioned.
Since pearlescent concentrates are mainly added to formulations containing anionic surfactants, anionic emulsifiers are preferred emulsifiers (B).
In addition, the pearlescent concentrates accord-ing to the invention, which contain only nonionic, zwitterionic and/or ampholytic surfactants, have proved to be particularly universally usable and to be partic-ularly compatible with water-cor.taining preparations of water-soluble surfactants of any type and any ionicity.
Accordingly, the use of surfactants from these classes is also preferred.
The presence of low molecular weight polyhydric alcohols is crucial to the flowability or pumpability of the pearlescent concentrates according to the invention t 21 U3~7~
WO ~2/13512 11 PC~/EP92/00179 and also to their resistance to bacterial and fungal contamination.
Preferred low molecular weight polyhydric al-cohols contain 2 to 6 carbon atoms and 2 to 6 hydroxyl groups. Alcohols such as these are, for example, ethylene glycol, 1,2- and 1,3-propylene glycol, glycer-ol, di- and triethylene glycol, erythritol, arabitol, adonitol, xylitol, sorbitol, mannitol and dulcitol. It is particularly preferred to use glycerol, 1,2-propylene glycol, 1,3-propylene glycol and/or sorbitol.
The use of glycerol as the low molecular weight polyhydric alcohol leads to pearlescent concentrates which give the end products a particularly brilliant pearlescenceO
In addition to the components mentioned above, the pearlescent concentrates according to the invention essentially contain water.
In addition, the concentrates may contain small quantities of buffers to adjust the pH to values in the range from 2 to 8, for example citric acid and/or sodium citrate, and also inorganic salts, for example sodium chloride, as thickener.
Although the pearlescent concentrates are normal-ly free from preservatives, small quantities of commer-cially available preservatives - introduced for example through certain starting materials - may be present in exceptional cases.
The pearlescent concentrates according to the invention are pumpable at least over a temperature range of 5 to 40'C and remain stable in storage for prolonged periods, i.e. for at least about 3 months.
The pearlescent concentrates according to the invention are preferably prepared by initially heating components (A), (B) and (C) together to a temperature approximately 1 to 30-C above the melting point. In 2~ i3~7~

most cases, this will be a temperature in the range from about 60 to 90-C. The water heated to substantially the same temperature is then added to this mixture. Where an ionic water-soluble surfactant is used as the emul-sifier, it may be preferred to dissolve it in the aqueous phase and to introduce it together with the water into the mixture. The aqueous phase may even already contain the buffer substances in dissolved form.
The dispersion formed is then cooled with continuous stirring to room temperature, i.e. to around 251C. In most cases, the viscosity of the pearlescent concentrate is so low that there is no need to use special stirring units, such as homogenizers or other high-speed mixers.
The pearlescent concentrates according to the invention are suitable for the production of clouded and pearlescent, liquid aqueous preparations of water-solu-ble surfactants. They may be incorporated, for example, in liquid detergents, such as dishwashing detergents, liquid light-duty detergents and liquid soaps but are preferably incorporated in liquid personal hygiene and body-care preparations, such as for example shampoos, liquid hand and body soaps, shower bath preparations, bath additives (foam baths), hair rinses or hair dyes.
To produce pearlescence, the pearlescent concen-trates according to the invention are added to the clear aqueous preparations at 0 to 40 C in a quantity of 1 to 10% by weight and more especially in a quantity of 1.5 to 5% by weight of the preparation and are dispersed therein with stirring. A metallic, dense to slightly lustrous, extremely dense pearlescence is obtained, t depending on the preparation and the concentration used.
The following Examples are intended to illustrate the invention without limiting it in any way.

21~3~

Examples 1. Pearlescent concentrates Pearlescent concentrates having the compositions shown in Table 1 were prepared. The components shown in the form of trade names are the following substances:
Ethylene glycol distearate (at least 90% diester) (HENKEL) 2 Coconut oil fatty acid monoethanolamide (CTFA
name: Cocamide MEA (approx. 95% amide)) (HENKEL) C~mposition of the fatty acid:
approx. 56% lauric acid approx. 21% myristic acid approx. 10% palmitic acid approx. 13% stearic acid and oleic acid 3 Palmitic/stearic acid mixture (approx. 1:1) 4 Fatty alcohol polyglycol ether (CTFA name:
Laureth-10 (approx. 74% C12~l~ fatty alcohol)) (HENKEL) Sodium lauryl ether sulfate (CTFA name: Sodium Laureth Sulfate (approx. 72% active substance)) (HENKEL) 6 Clz_l4 fatty alcohol + 4 ethylene oxide (HENKEL) Aqueous solution of a fatty acid amide derivative of betaine structure having the formula R-CONH-(CH2)3-N+( C~3 )2-CH2-COO (CTFA name Cocamido-propyl Betaine (approx. 30% active substance, approx. 5% NaCl)) (HENKEL) 21 ~33~7~
PCT/EP92Jo0179 Wo 92/13512 14 8 C~2l~ fatty alcohol + 3 ethylene oxide (HENKEL) 9 Polyol fatty acid ester (CTFA name: PEG-7-Gly-ceryl Cocoate) (HENKEL) 86% Water N 2 1 ~ 3 ~ 7 ~
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WO 92/1~512 16 PCT/EP92/00179 Application Examples l) Shower bath Parts by weight Texapon~R~N25l1 35 Dehyton(R)K 7 Lamepon~R~Sl2 5 Pearlescent concentrate l 3 Water ad 100 The viscosity of the shower bath was then adjusted to 4,000 mPas by addition of sodium chloride.

11 Sodium lauryl ether sulfate (CTFA name: Sodium Laureth Sulfate (approx. 28% active substance in water) (HENREL) 12 Protein hydrolyzate fatty acid condensate potassium salt (CTFA name: Potassium Coco-Hydrolyzed Animal Collagen) (HENREL) 2) Mild shampoo Parts by weight Texapon(R)ASV13 14 Texapon(R~SB 3~4 10 Dehyton~R~G15 14 Nutrilan(R)I S016 2.5 Pearlescent concentrate 2 2 Water ad 100 The viscosity was then adjusted to S,000 mPas by addition of sodium chloride and Arlypon(R~F (narrow-range ethoxylated fatty alcohol) (HENKEL)).

2~ 33~7~
W0 92~13512 17 PCT/EP92/00179 13 A mixture of special fatty alcohol ether sulfates (CTFA name: Sodium Laureth Sulfate (and) Magnesium Laureth Sulfate (and) Sodium Laureth 8-Sulfate (and) Magnesium Laureth 8-sulfate ~and~ Sodium Oleth Sulfate (and) Magnesium Oleth Sulfate (approx. 30 active substance in water)) (HENKEL) Sulfosuccinic acid semiester based on an alkyl polyglycol ether, di Na salt (CTFA name: disodium laureth sulfosuccinate (approx. 40% active substance in water)) (HENKEL) 15 Amphoteric fatty acid amide derivative (N-hydroxy-ethyl-N-cocoalkylamidoethyl glycinate, Na salt) (CTFA
name: Cocoamphodiacetate (approx. 30~ active sub-stance in water)) (HENKEL) 16 Partial protein hydrolyzate of degraded bovine collagen (CTFA name: Hydrolyzed Animal Protein) (HENKEL) 3) Foam bath Parts by weight Texapon(R~N 4017 40 Dehyton(R~K 6.5 Dehyton(R~G 6.5 Cetiol~R) HE 5 Pearlescent concentrate 3 5 Water ad 100 The viscosity was then adjusted to 6,000 mPas by addition of sodium chloride.
17 Sodium lauryl ether sulfate (CTFA name: Sodium Laureth Sulfate (approx. 28% active substance in water)) (HENKEL)~

Claims (13)

WO 92/13512 18 PCT/EP92/00179

1. A pearlescent concentrate in the form of a free-flowing, aqueous dispersion, characterized in that it contains (A) 15 to 40% by weight pearlescing components, (B) 5 to 55% by weight emulsifiers and (C) 15 to 40% by weight low molecular weight, polyhydric alcohols.

2. A pearlescent concentrate as claimed in claim 1, characterized in that it contains (A) 20 to 30% by weight pearlescing components, (B) 10 to 35% by weight emulsifiers and (C) 20 to 40% by weight low molecular weight, polyhydric alcohols.

3. A pearlescent concentrate as claimed in claim 1 or 2, characterized in that it contains as pearlescing components (A1) esters corresponding to formula (I) R1 - (OCnH2n)x - OR2 (I) in which R1 is a linear C14-22 fatty acyl group, R2 is hydrogen or a group R1, n = 2 or 3 and x is a number of from 1 to 4, and/or (A2) monoalkanolamides corresponding to general formula (II) R3 - CO - NH - X (II) in which R3 is an alkyl group containing 8 to 22 and, more especially, 8 to 18 carbon atoms and X is a -CH2-CH2-OH group, a -CH2-CH2-CH2-OH group or a -C(CH3)2-OH group, and/or (A3) linear, saturated C16-22 fatty acids.

4. A pearlescent concentrate as claimed in claim 3, characterized in that at least 70% by weight and, in particular, at least 90% by weight of the pearlescing components consist of ethylene glycol distearate.

5. A pearlescent concentrate as claimed in any of claims 1 to 4, characterized in that it contains nonionic, ampho-lytic and/or zwitterionic emulsifiers as emulsifiers.

6. A pearlescent concentrate as claimed in any of claims 1 to 5, characterized in that the emulsifiers present are nonionic surfactants, more particularly from the group con-sisting of (B1) adducts of 2 to 30 mol ethylene oxide and/or 0 to 5 mol propylene oxide with linear C8-22 fatty alcohols, with C12-22 fatty acids and with alkyl phenols contain-ing 8 to 15 carbon atoms in the alkyl group, (B2) C12-22 fatty acid monoesters and diesters of adducts of 1 to 30 mol ethylene oxide with glycerol, (B3) glycerol monoesters and diesters and sorbitan monoes-ters and diesters of saturated and unsaturated C8-22 fatty acids and ethylene oxide adducts thereof, (B4) C8-22 alkyl mono- and -oligoglycosides and ethoxylated analogs thereof and

7. A pearlescent concentrate as claimed in any of claims 1 to 5, characterized in that zwitterionic surfactants, more especially selected from the group of betaines, are present as emulsifiers.

8. A pearlescent concentrate as claimed in any of claims 1 to 4, characterized in that anionic emulsifiers are present as emulsifiers.

9. A pearlescent concentrate as claimed in any of claims 1 to 8, characterized in that the low molecular weight polyhydric alcohol contains 2 to 6 carbon atoms and 2 to 6 hydroxyl groups.

10. A pearlescent concentrate as claimed in claim 9, characterized in that the low molecular weight polyhydric alcohol is selected from the group consisting of glycerol, 1,2-propylene glycol, 1,3-propylene glycol and sorbitol.

11. A pearlescent concentrate as claimed in claim 10, characterized in that glycerol is present as the low molecular weight polyhydric alcohol.

12. A process for the production of the pearlescent concentrates claimed in any of claims 1 to 10, charac-terized in that a mixture of components (A), (B) and (C) is heated to a temperature 1 to 30°C above the melting point of the mixture, mixed with the necessary quantity of water at substantially the same temperature and the resulting mixture is subsequently cooled to room temperature.

13. A process for the production of clouded and pearles-cent free-flowing, aqueous preparations of water-soluble surfactants, characterized in that the pearlescent con-centrates claimed in any of claims 1 to 11 are added to the clear aqueous preparations at 0 to 40°C in a quantity of from 0.5 to 10% by weight and more especially in a quantity of from 1.5 to 5% by weight and are dispersed therein with stirring.