EP0724626B1 - Soap tablets - Google Patents

Abstract

PCT No. PCT/EP94/03454 Sec. 371 Date Apr. 26, 1996 Sec. 102(e) Date Apr. 26, 1996 PCT Filed Oct. 20, 1994 PCT Pub. No. WO95/11959 PCT Pub. Date May 4, 1995A bar soap comprising: A) from about 70 to about 85% by weight of at least one fatty acid salt, B) from about 0.5 to about 10% by weight of at least one fatty acid, C) from about 1 to about 10% by weight of at least one alkyl ether sulfate, and D) from about 0.1 to about 1% by weight of at least one of an alkyl oligoglycoside and an alkenyl oligoglycoside.

Description

Field of the Invention

The invention relates to soap bars containing fatty acid salts, fatty acids, alkyl ether sulfates, alkyl and / or alkenyl oligoglycosides and optionally other auxiliaries and additives.

State of the art

Modern bar soaps, especially toilet or fine soaps, are usually based on mixtures of beef tallow and coconut oil in a ratio of about 8: 2. This fat deposit is hydrolyzed by adding sodium hydroxide solution to the basic soap, which contains other additives such as. B. humectants, fillers and binders, superfatting agents, dyes and perfumes etc. are added. Usual fine soaps contain about 80% fatty acid salts, 10% water and ad 100% auxiliaries and additives. The large number of products offered to the consumer document the lively market interest and nevertheless make it clear that there is a constant need among consumers for further improved products, which are characterized in particular by improved dermatological compatibility, Characterized stronger foaming power, higher creaminess, regreasing, rinsing ability, skin feeling and the like. Soap manufacturers, on the other hand, are looking for soap formulations which, for example, lead to pieces with higher breaking strength or allow the problem-free incorporation of certain surfactants, such as alkyl sulfates. An overview of this topic can be found, for example, in J.Am. Oil.Chem.Soc. 59: 442 (1982).

With regard to the production of bar soaps, a very large number of processes from the prior art can of course be looked back on. A distinction must essentially be made here between synthetic, "soap-free" soaps, so-called syndets, and in particular combinations of fatty acid salts and synthetic surfactants ("combibars"). To produce combibars, it is proposed, for example, in EP-A-0 176 330 (Unilever) to combine fatty acid soaps with salts of isethionic acid. From the publications EP-A 0 189 332 , EP-A 0 472 320 and EP-A 0 508 006 (Unilever) the use of fatty acid isethionates as a synthetic component of combibars is known.

Interest in alkyl glucosides, as a class of nonionic, mild surfactants, for making toilet soaps has also increased in the past. For example, a technical bulletin from Rohm & Haas on "Triton CG-110" suggests adding this C ₈ -C ₁₀ -alkyl oligoglucoside to a basic soap in amounts of 2% by weight. From German Auslegeschrift DE-AS 593 422 (Th.Boehme) it is known that the addition of 10 to 15 wt .-% of a cetyl maltoside with a basic soap mixture improves the washing power.

The patents US 4,536,318 and US 5,599,188 (Procter & Gamble) disclose foaming mixtures of alkyl glucosides and soaps which are described as being fundamentally suitable for the production of bar soaps. Toilet soaps are also known from European patent applications EP-A 0 227 321 , EP-A 0 308 189 and EP-A 308 190 (Procter & Gamble), which contain cationic polymers in addition to soaps and alkyl glucosides.

According to the teaching of US Pat. No. 5,043,091 (Colgate), the addition of alkyl glucosides to soaps which contain alkyl benzene sulfonates and alkyl sulfates can improve their mechanical properties during manufacture.

From European patent application EP-A 0 463 912 (Colgate) toilet soaps are known which contain 45 to 95% by weight of C ₈ -C ₂₄ fatty acid soaps, 1 to 20% by weight of alkyl glucosides, humectants and optionally anionic surfactants and / or Contain fatty acids. However, the document expressly recommends using alkyl glucosides in amounts well above 1.5% by weight. Alkyl ether sulfates are also mentioned as possible anionic cosurfactants, but the exemplary embodiments only disclose combinations of fatty acids, soaps and alkyl glucosides.

Despite this extensive state of the art, the known solutions are still not entirely satisfactory. In particular, the workability of the pieces (smoothness, color stability at high temperatures), the creaminess of the foam and the hardness resilience still leave something to be desired.

The object of the invention is therefore to be seen in providing new bar soap formulations with a complex property profile which are free from the disadvantages described.

Description of the invention

• a) 70 bis 85 Gew.-% Fettsäuresalze,
• b) 0,5 bis 10 Gew.-% Fettsäuren,
• c) 1 bis 10 Gew.-% Alkylethersulfate,
• d) 0,1 bis 1 Gew.-% Alkyl- und/oder Alkenyloligoglykoside

sowie gegebenenfalls weitere Hilfs- und Zusatzstoffe.The invention relates to bar soaps containing

• a) 70 to 85% by weight of fatty acid salts,
• b) 0.5 to 10% by weight of fatty acids,
• c) 1 to 10% by weight of alkyl ether sulfates,
• d) 0.1 to 1 wt .-% alkyl and / or alkenyl oligoglycosides

and, if appropriate, further auxiliaries and additives.

• a) 73 bis 80 Gew.-% Fettsäuresalze,
• b) 2 bis 6 Gew.-% Fettsäuren,
• c) 2 bis 4 Gew.-% Alkylethersulfate,
• d) 0,5 bis 1 Gew.-% Alkyl- und/oder Alkenyloligoglykoside

sowie gegebenenfalls weitere Hilfs- und Zusatzstoffe enthalten.In a preferred embodiment of the invention, the bar soaps

• a) 73 to 80% by weight of fatty acid salts,
• b) 2 to 6% by weight of fatty acids,
• c) 2 to 4% by weight of alkyl ether sulfates,
• d) 0.5 to 1 wt .-% alkyl and / or alkenyl oligoglycosides

and optionally contain other auxiliaries and additives.

Surprisingly, it was found that the addition of defined amounts of 0.1 to 1% by weight of alkyl and / or alkenyl oligoglycosides significantly improves the creaminess and hardness resistance and the lime soap dispersibility of commercially available combibars based on soaps and alkyl ether sulfates. The soap bars according to the invention also have improved color stabilization during manufacture and are distinguished by a particularly smooth surface after the mechanical deformation. The invention further includes the finding that the use of more than about 1% by weight of alkyl and / or alkenyl oligoglycosides leads to a sudden deterioration in the complex property profile. The observed positive effect is also closely related to the alkyl ether sulfate used and cannot be readily transferred to other anionic base surfactants such as alkyl sulfates or ester sulfonates.

Fatty acid salts and fatty acids

The fatty acid salts are soaps that follow the formula (I)

R ¹ CO-ONa (I)

in which R ¹ CO represents an aliphatic acyl radical having 6 to 22 carbon atoms. Typical examples are the sodium salts of caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, palmoleylic acid, stearic acid, isostearic acid, oleic acid, elaidic acid, petroselinic acid, Linoleic acid, linolenic acid, elaeostearic acid, arachic acid, gadoleic acid, behenic acid and erucic acid as well as their technical mixtures, such as those which occur in the pressure splitting of natural fats and oils. Technical soap mixtures based on C ₁₂ -C ₁₈ -, C ₁₂ -C ₁₄ coconut fatty acid and / or C ₁₆ -C ₁₈ tallow fatty acid are particularly preferred.

Aliphatic carboxylic acids of the formula (II) are suitable as fatty acids,

R ² CO-OH (II)

in which R ² CO represents an aliphatic acyl radical having 6 to 22 carbon atoms. Typical examples are caproic acid, caprylic acid, lauric acid, palmitic acid, Palmoleylsäure, stearic acid, isostearic acid, oleic acid, elaidic, Petroselin acid, linoleic acid, linolenic acid, arachidic acid, Gadoleinsäure, behenic acid and erucic acid and technical mixtures such as for example in the Pressure splitting of natural fats and oils occur. Technical soap mixtures based on C ₁₂ -C ₁₈ -, C ₁₂ -C ₁₄ coconut fatty acid and / or C ₁₆ -C ₁₈ tallow fatty acid are particularly preferred.

Alkyl ether sulfates

The alkyl ether sulfates used in the context of the invention follow the formula (III),

R ³ O- (CH ₂ CH ₂ O) _n H (III)

in which R ^{3 is} a linear or branched alkyl and / or alkenyl radical having 6 to 22 carbon atoms and n is a number from 1 to 10. They are known addition products of ethylene oxide onto fatty alcohols or oxo alcohols, which can have a conventional or narrow homolog distribution. Typical examples are adducts of 1 to 5 mol of ethylene oxide with in each case 1 mol of C _12/14 or C _12/18 coconut _fatty alcohol.

Alkyl and / or alkenyl oligoglycosides

Alkyl and alkenyl oligoglycosides are known substances which can be obtained by the relevant processes in preparative organic chemistry and follow the formula (IV) ,

R ⁴ O- [G] _p (IV)

in which R ^{4 is} a linear or branched alkyl and / or alkenyl radical having 6 to 22 carbon atoms, G is a sugar radical having 5 or 6 carbon atoms and p is a number from 1 to 10.

Representative of the extensive literature, reference is made here to the documents EP-A1-0 301 298 and WO 90/3977 . The alkyl and / or alkenyl oligoglycosides can be derived from aldoses or ketoses with 5 or 6 carbon atoms, preferably glucose. The preferred alkyl and / or alkenyl oligoglycosides are thus alkyl and / or alkenyl oligo glucosides .

The index number p in the general formula (IV) indicates the degree of oligomerization (DP degree), ie the distribution of mono- and oligoglycosides, and stands for a number between 1 and 10. While p in a given compound must always be an integer and here can assume the values p = 1 to 6 in particular, the value p for a certain alkyl oligoglycoside is an analytically determined arithmetic parameter, which usually represents a fractional number. Alkyl and / or alkenyl oligoglycosides with an average degree of oligomerization p of 1.1 to 3.0 are preferably used. From an application point of view, preference is given to those alkyl and / or alkenyl oligoglycosides whose degree of oligomerization is less than 1.7 and in particular between 1.2 and 1.4.

The alkyl or alkenyl radical R ⁴ can be derived from primary alcohols having 6 to 11, preferably 8 to 10, carbon atoms. Typical examples are capronic alcohol, caprylic alcohol, capric alcohol and undecyl alcohol and their technical mixtures, such as are obtained, for example, in the hydrogenation of technical fatty acid methyl esters or in the course of the hydrogenation of aldehydes from Roelen's oxosynthesis. Alkyl oligoglucosides of chain length C ₈ -C ₁₀ (DP = 1 to 3) are preferred, which are obtained as a preliminary step in the separation of technical C ₈ -C ₁₈ coconut fatty alcohol by distillation and with a proportion of less than 6% by weight of C ₁₂ - Alcohol can be contaminated and alkyl oligoglucosides based on technical C _9/11 oxo alcohols (DP = 1 to 3).

The alkyl or alkenyl radical R ⁴ can also be derived from primary alcohols having 12 to 22, preferably 12 to 14, carbon atoms. Typical examples are lauryl alcohol, Myristyl alcohol, cetyl alcohol, palmoleyl alcohol, stearyl alcohol, isostearyl alcohol, oleyl alcohol, elaidyl alcohol, petroselinyl alcohol, arachyl alcohol, gadoleyl alcohol, behenyl alcohol, erucyl alcohol, and their technical mixtures, which can be obtained as described above. Alkyl oligoglucosides based on hardened C _12/14 coconut alcohol with a DP of 1 to 3 are preferred.

Auxiliaries and additives

The bar soaps according to the invention can contain, for example, builders as additives. For this purpose, finely divided, water-insoluble alkali aluminum silicates come into consideration, the use of synthetic, bound water-containing crystalline sodium aluminosilicates and in particular zeolite A being particularly preferred here; Zeolite NaX and its mixtures with zeolite NaA can also be used. Suitable zeolites have a calcium binding capacity in the range from 100 to 200 mg CaO / g. A zeolite NaA which is obtainable under the trade name WESSALITH ^(R) P (Degussa) and contains about 20% by weight of bound water in an amount of 8 to 15% by weight is preferably used.

Glycerin, fatty alcohols having 12 to 22 carbon atoms, fatty acid glycerides of C ₁₂ -C ₂₂ fatty acids or corresponding wax esters can be used as plasticizers or binders.

Other constituents of the recipe can also be nonionic surfactants, for example polyglycol ethers with HLB values in the range from 12 to 18 and / or protein fatty acid condensation products. The latter have long been commercially available under the trademarks LAMEPON ^(R) or MAYPON ^(R) . The addition of W / O emalgators from the group of pentaerythritol di-fatty acid esters and citric acid di-fatty acid esters has also proven to be particularly advantageous. The recipes may also contain white pigments (e.g. BAYERTITAN ^(R) ), colors, fragrances and preservatives (e.g. IRGASAN ^(R) DP 300, FARNESOL ^(R) , GRILLOCIN ^(R) CW 90). Finally, the bar soaps according to the invention can contain small amounts of water.

The auxiliaries and additives can be present in total in amounts of 1 to 5, preferably 2 to 3,% by weight, based on the bar soaps.

Production of bar soaps

The bar soaps according to the invention can be produced in the manner customary for such products, the combination of soap according to the invention with alkyl ether sulfates and alkyl oligoglucosides, in particular, resulting in a particularly readily formable mass which is plastic under heat and hard after cooling, and the shaped products are smooth Have surface. Usual methods for mixing or homogenizing, kneading, optionally pelleting, extrusion, optionally pelleting, extruding, cutting and bar pressing are known to the person skilled in the art and can be used for Production of the bar soaps according to the invention can be used. The preparation is preferably carried out in the temperature range from 60 to 90 ° C., the meltable starting materials being introduced into a heatable kneader or mixer and the non-melting components being stirred in. For homogenization, the mixture can then be passed through a sieve before the shaping follows.

Industrial applicability

The bar soaps according to the invention have a smooth surface and are distinguished by particularly high foaming power, good foam resistance, creaminess, lime soap dispersing power and excellent skin-cosmetic compatibility. During production, the bar soaps prove to be unusually stable in color.

Examples I. Recipes

Table 1 Soap formulations Components R1 % R2 % R3 % R4 % R5 % R6 % Soap base 94.0 94.5 94.0 94.0 94.0 94.0 Ether sulfate 3.5 3.5 3.5 3.5 - - Alkyl sulfate - - - - 3.5 - Ester sulfonate - - - - - 3.5 Alkyl glucoside 0.5 1.0 1.5 2.0 1.0 1.0

• a) Soap base: 47% by weight of C _16/18 tallow fatty acid sodium salt, 31% by weight of C _12/18 coconut _fatty acid sodium salt, 5% by weight of C _12/18 coconut _fatty acid, 1% by weight of glycerin , ad 100 wt .-% usual additives and water;
• b) ether sulfate: C _12/14 coconut fatty alcohol 3.6 EO sulfate sodium salt [Texapon ^(R) K 14 S (70% by weight), Henkel KGaA, Düsseldorf / FRG];
• c) alkyl sulfate: lauryl sulfate sodium salt;
• d) ester sulfonate: methyl methyl sulfo coconut fatty acid salt;
• e) Alkyl glucoside: C _8/16 coconut alkyl oligoglucoside, DP = 1.4 [Plantaren ^(R) APG 2000 CS-UP, Henkel KGaA, Düsseldorf / FRG].

Formulations 1 and 2 are inventive, formulations 3 to 6 are used for comparison. Excipients (perfume oil, colors and preservatives) ad 100%. All weight data are% by weight.

II. Evaluation of the recipes

• a) Glätte der Oberfläche der Stückseifen
  • I = sehr glatt
  • II = weniger glatt
• b) Verfärbung der Stückseifen während der Extrusion
  • 0 = keine Verfärbung
  • I = leichte Verfärbung
  • II = deutliche Verfärbung
• c) Cremigkeit des Schaums
  • I = cremiger Schaum
  • II = grobporiger Schaum
• d) Kalkseifendispergiervermögen
  • I = gut
  • II = weniger gut

Die Ergebnisse sind in Tabelle 2 zusammengefaßt: Tabelle 2 Anwendungstechnische Ergebnisse Rezeptur Glätte Verfärbung Cremigkeit Kalkseifendispergiervermögen R1 I 0 I I R2 I 0 I I R3 I I II II R4 II I II II R5 II I II II R6 II II II II Die erfindungsgemäßen Beispiele (Rezepturen 1 und 2) und die Vergleichsbeispiele (Rezepturen 3 bis 6) zeigen, daß

• ^∗∗∗ das komplexe Anforderungsprofil - Glätte der Oberfläche, keine Verfärbung während der Herstellung, Cremigkeit des Schaumes und hohes Kalkseifendispergiervermögen - ausschließlich im Rahmen der erfindungsgemäßen Rezepturen erreicht wird;
• ^∗∗∗ der Zusatz von mehr als 1 Gew.-% an Alkylglucosid zu einer sprunghaften Verschlechterung des Eigenschaftsprofils führt;
• ^∗∗∗ die Verbesserung des Eigenschaftsprofils der Stückseifen abhängig von der Natur des anionischen Basistensids ist.

• a) Smoothness of the surface of the bar soaps
  • I = very smooth
  • II = less smooth
• b) discoloration of the soap bars during extrusion
  • 0 = no discoloration
  • I = slight discoloration
  • II = significant discoloration
• c) Creaminess of the foam
  • I = creamy foam
  • II = coarse-pored foam
• d) Lime soap dispersing power
  • I = good
  • II = less good

The results are summarized in Table 2: Table 2 Application results Recipe smoothness Discoloration Creaminess Lime soap dispersing power R1 I. 0 I. I. R2 I. 0 I. I. R3 I. I. II II R4 II I. II II R5 II I. II II R6 II II II II The examples according to the invention (recipes 1 and 2) and the comparative examples (recipes 3 to 6) show that

• ^Komplexe the complex requirement profile - smoothness of the surface, no discoloration during production, creaminess of the foam and high lime soap dispersing capacity - can only be achieved within the scope of the recipes according to the invention;
• ^∗∗∗ the addition of more than 1% by weight of alkyl glucoside leads to a sudden deterioration in the property profile;
• ^∗∗∗ the improvement of the property profile of bar soaps depends on the nature of the anionic base surfactant.

Claims (5)

1. Bar soaps containing

   a) 70 to 85% by weight of fatty acid salts,

   b) 0.5 to 10% by weight of fatty acids,

   c) 1 to 10% by weight of alkyl ether sulfates,

   d) 0.1 to 1% by weight of alkyl and/or alkenyl oligoglycosides

   and optionally other auxiliaries and additives.
2. Bar soaps as claimed in claim 1, characterized in that they contain fatty acid salts corresponding to formula (I):
   
           R ¹ CO-ONa     (I)
   
   in which R¹CO is an aliphatic acyl radical containing 6 to 22 carbon atoms.
3. Bar soaps as claimed in claims 1 and 2, characterized in that they contain fatty acids corresponding to formula (II):
   
           R ² CO-OH     (II)
   
   in which R²CO is an aliphatic acyl radical containing 6 to 22 carbon atoms.
4. Bar soaps as claimed in claims 1 to 3, characterized in that they contain alkyl ether sulfates corresponding to formula (III):
   
           R ³ O-(CH ₂ CH ₂ O) _n H     (III)
   
   in which R³ is a linear or branched alkyl and/or alkenyl radical containing 6 to 22 carbon atoms and n is a number of 1 to 10.
5. Bar soaps as claimed in claims 1 to 4, characterized in that they contain alkyl and/or alkenyl oligoglycosides corresponding to formula (IV):
   
           R ⁴ O-[G] _p      (IV)
   
   in which R⁴ is a linear or branched alkyl and/or alkenyl radical containing 6 to 22 carbon atoms, G is a sugar unit containing 5 or 6 carbon atoms and p is a number of 1 to 10.