EP0109022B1

EP0109022B1 - Concentrated liquid detergent composition adapted for preparing liquid light duty laundry or dishwashing detergents

Info

Publication number: EP0109022B1
Application number: EP83111093A
Authority: EP
Inventors: Giuseppe Toninelli; Giovanni Osti
Original assignee: Mira Lanza SpA
Current assignee: Mira Lanza SpA
Priority date: 1982-11-09
Filing date: 1983-11-07
Publication date: 1987-08-12
Also published as: IT1164469B; DE3372986D1; IT8212659A0; ES527093A0; ATE28893T1; EG16154A; ES8504241A1; EP0109022A3; EP0109022A2

Abstract

A composition comprising a mixture of anionic surfactants, of the type alkylaryl sulfonates, alkansulfonates, alkylethoxysulfonates, non-ionic surfactants, of the type oxyethylene polycondensates of alkanolamides of fatty acids, alcohols, alkylphenols, and solvents of the type alcohols, glycols, glycol-ethers and ketones having a low molecular weight. The ratio of anionic to non-ionic surfactants in the said composition is comprised in the range between 10 : 1 to 70 : 1, with a total amount of active substances in the composition ranging between 60 to 75%. The composition is dissolved in water at the ambient temperature in a short time, such as a few minutes, by simple manual shaking, providing a ready to use liquid detergent with a pH between 6,5 to7,5. In order to obtain a diluted product having a sufficiently high viscosity, high molecular weight oxyethylene homopolymers may be incorporated in the composition, or the composition may be additivated, upon the dilution thereof, with suitable viscosity-enhancing materials, such as poly-acrylic acids, common electrolytes such as alkaline chlorides and sulfates, and alkanolamides of fatty acids.

Description

This invention relates to liquid detergents, and more particularly to a liquid light duty detergent composition complete with all the ingredients, including the minor components, having a high concentration of active materials, in the form of a viscous liquid, quickly dilutable in water, adapted for preparing liquid detergents ready to be used.
Detergents, and more particularly liquid detergents, are substantially formed by surfactants, either of anionic, non-ionic or amphoteric type, defined as active agents, and by various materials added to obtain particular effects, such as for example bleaching agents or builders in case of laundering products, or abrasive powders in case of bathroom or kitchen-cleaning products, and/or minor agents such as electrolytes, perfumes, anti-fermentation agents, dyes, and the like.
Among the anionic surfactants, the most widely used in the straight chain alkylaryl sulfonate, in the form of its sodium, potassium, ammonium and alkanol ammonium salts (LAS Na, LAS K, LAS Tea), or combination of the above. In addition to alkylaryl sulfonates, also sodium alkane-sulfonates (SAS Na), sulfonated -olefines, and sodium alkylethoxy sulfates (AES Na) of low ethoxylation type are frequently used.
Among the non-ionic surfactants, the most widely used are the ethylene oxide condensates of alkanolamides of fatty acids, fatty alcohols, or alkylphenols.
Among the amphoteric surfactants, the betaine derivatives, imidazole derivatives, and amine oxides are widely used.
Concentrated detergent compositions, comprising a mixture of anionic, non-ionic and amphoteric surfactants, are known.
So, for instance, in the U.S. patent No. 3,574,125 a process is described according to which a suitable plasticizer is added to a concentrate consisting essentially of an anionic aliphatic capillary-active sulfate or Clg--Cl4 carboxylate, which plasticizer promotes the dissolving rate in water of the anionic detergent concentrate. However, the above composition is intended for use in factory, for the mass production of diluted liquid detergents, and not for the extemporary household production of little amounts of diluted detergents, without the aid of mechanical stirring equipments. In fact, we have made experiments with the compositions cited in Examples 10, 11 and 12 of the above patent No. 3,574,125 and have found that the solution of the above compositions by simply manual shaking of the dissolving container took place after more than 60 minutes.
In the U.S. patent No. 3,709,838 is described a polyfunctional essentially 100% active stable liquid detergent composition which may be diluted at commercially acceptable concentrations. Also in this case, however, the dilution must be performed at industrial level. In fact, we have made experiments with the compositions cited in Examples 6 and 7 of the said patent and have found that the solution of the above composition by simply manual shaking of the dissolving container took place after a time varying from 30 to 60 minutes, that means a time which is not acceptable for the purposes of the present invention.
The U.S. patents Nos. 4,079,078 and 4,105,592 as well as U.K. patent No. 1,527,141 are all concerned with heavy duty laundry detergents, in which the ratio between non-ionic and anionic surfactants is comprised between 5:1 and 2,5:1, which renders the said detergent compositions fully unsuitable for the use as dishwashing detergents. Moreover, the detergent compositions disclosed in the above patents contain a certain amount of free ethanolamine in order to confer an alkaline pH to the washing solution.
We have made experiments on the composition of Example 1 of the U.S. patent No. 4,105,592, which may be considered as representative of the detergent compositions of the above mentioned prior art patents.
By diluting with water the detergent composition of the above mentioned Example 1 to the desired concentration of use, same was found to have a fully satisfactory dissolving rate.
However, by modifying the composition of the above mentioned prior art patent so as to obtain: a) a concentrate containing about the 70% of active matter; b) by reducing the non-ionic surfactants content in the composition and c) by eliminating the free alkali in the composition so as to obtain a neutral pH value, as highly desirable especially for a light duty and dishwashing detergent, a dissolving time of more than 60 minutes was obtained.
It is therefore the main object of this invention to provide a concentrated detergent composition for the preparation of light duty of dishwashing detergents having an active agent content of preferably, from 65 to 75%, which is readily soluble in water with dissolving rates from 1 to 5 minutes, by simply manual shaking of the dissolving container.
The main obstacle in the formulation of such a product is the low water solubilization speed of almost all the most-commonly used surfactants when they are in a highly concentrated form, which is, obviously, the only possible form for the product according to this invention.
The following Table 1 evidences the above statements by reporting the long solution periods of some presently-marketed products (the indicated periods are those required to obtain the solubilization in water, at the ambient temperature, by simple manual shaking, for preparing final solutions with 12% concentration of active agent).
Even by mixing some surfactants of the indicated types with each other, no successful results are obtained; on the contrary, in certain cases, the solution time increases with respect to that of the individual components, as reported in the Table 2.
However, according to this invention, by mixing one or more of selected anionic surfactants with one or more selected non-ionic surfactants and one or more polar solvents, selected from alcohols, glycols, glycol ethers or low molecular weight ketones, the desired result is obtained of a quick and easy solubilization in water, lower than 3 minutes in many cases, by simple dilution with minimum stirring.
Therefore, the object of this invention is to provide a complete detergent, represented by the composition of claim 1, characterized at the same time by the following features:

1) high concentration of active agent, above 60%, preferably between 65 to 75%, so as to permit the preparation of liquid detergents ready to be used from comparatively small volumes of product, by diluting them in water, up to final concentrations in the range of 10 to 30% of total active agent.
2) A ratio between anionic and non-ionic surfactant comprised between 10:1 and 70:1.
3) A pH of the diluted detergent comprised between 6.5 and 7.5.
4) Quick solubilization of the product in water, at the ambient temperature, by simple mixing and minimum stirring, within periods ranging from 1 to 5 minutes preferably of the order of 3 minutes.

All the previously specified anionic surfactants have proved to be suitable, namely the straight-chain alkylarylsulfonates, particularly the salts of potassium and triethanolamine, the sodium alkansulfonates and the sodium alkylethoxy sulfates containing 2 to 3 moles of ethylene oxide.
Advantageously, alkane-sulfonates having an alkylic chain length in the range C₁₀-₂₀ are used.
The said alkane-sulfonates may be used alone or in mixtures with alkylethoxy sulfates in a ratio 100:0 to 40:60.
Advantageously, the alkylethoxy sulfates comprise sodium salts of alkylsulfates with a chain length in the range Cg-₁₈, particularly C₉-₁₅ or C₁₂-₁₈, condensed with 3 moles of ethylene oxide.
As solvents, light alcohols with 1 to 3 carbon atoms, low molecular weight ketones such as acetone and methylethylketone, and some glycol ethers such as the monomethyl- and monoethyl-ether of ethylene glycol may be used.
The total active agents are formed, in addition to the anionic surfactant main constituents, also by non-ionic surfactants in smaller percentages, mainly as foam stabilizers and, due to their dispersing and fluidizing characteristics, in order to permit the admixture of minor additives, such as perfumes, into the composition without impairing the peculiar characteristics, particularly the high solubilization property of the composition.
As non-ionic surfactants, the invention advantageously uses alkylphenols condensed with 4 to 9 moles of ethylene oxide, C₉-C₁₅ straight chain alcohols condensed with 7 to 15 moles of ethylene oxide, and alkanolamides of fatty acids, e.g. of the coconut type, condensed with 1 to 5 moles of ethylene oxide.
In order to obtain, after dilution, a final product ready to be used and having a sufficiently high viscosity, comparable with that of the presently-marketed conventional products, the concentrated composition may incorporate therein water-soluble polymeric materials of the oxyethylene homopolymer type, e.g. those having a molecular weight in the range 400,000 to 5,000,000 and marketed under the Trademark "Polyox" registered by Union Carbide, preferably in concentrations of 0.005 to 3% more preferably of 0.05 to 2%.
According to still another feature of the invention, the same objective of obtaining a diluted detergent composition with increased viscosity can be achieved by adding, separately, to the said concentrated composition during the dilution step, one or more viscosity-enhancing materials selected from the following groups:

1) polyacrylic acids, of appropriate molecular weight, in water emulsion, for example the Prinol series (a Rhom & Haas registered trademark) added according to a ratio of at least 1:20 (referred to the 100% polymer) into the concentrated composition.

These acids are neutralized, in the mixing and diluting step, by basic materials, such as alkaline hydrates, ammonium hydroxide, alkanolamines, admixtured into the concentrated composition for this purpose;

2) alkanolamides of fatty acids, preferably those having a chain length of C₁₀-₂₂, added according to a ratio of at least 1:20 into the concentrated composition;
3) electrolytes, particularly chloride and sulfates of alkaline metals, alkaline-earth metals, ammonium, added according to a ratio of at least 1:20 into the concentrated composition.

The following examples of formulations, within the scope of this invention, illustrate the capability of its practical realization; they are, however, of merely indicative and non-limitative character.
The main surfactants used in these examples are usually marketed and available materials, indicated by the symbols generally used to designate them in the technical literature (for example, LAS, SAS, AES), followed by the respective concentration of active agent.
Each formulation comprises the indication of the percentage composition, the contents of total active agent (anionic+non-ionic surfactants) and the solution time required to achieve the solubilization in water, at the ambient temperature, by simple manual shaking, to obtain diluted final solutions with 12% concentration of total active agent.

Example 1

Total active agent 65%
Solution time 2 minutes.

Example 2

Total active agent 70%
Solution time 4 minutes

Example 3

Total active agent 75%
Solution time 3 minutes

Example 4

Total active agent 75%
Solution time 2.5 minutes

Example 5

Total active agent 75%
Solution time 3 minutes

Example 6

(°) Oxyethylene polymer, a Union Carbide registered trademark, molecular weight 5,000,000.
Total active agent 72.5%
Solution time 4 minutes

Example 7

Example 8

A combination is reported here of a concentrated composition into which, in the dilution step, viscosity-enhancing materials are added.
In order to obtain a 12% diluted product of total active agent in the dilution step, a viscosity-enhancing material in the form of a polyacrylic acid in water emulsion and sodium chloride in the following ratios will be added to the composition A:
(°) polyacrylic acid, in 30% water emulsion, a Rohm & Haas registered trademark.

Claims

1. A detergent composition in the form of a viscous liquid, quickly soluble in water at ambient temperatures with a minimum manual shaking, adapted for an immediate preparation of liquid detergents ready to be used, comprising:

a) one or more anionic surfactants, selected from the alkylaryl-sulfonates, alkane-sulfonates, sulfonated olefines, alkylethoxy sulfates and the sodium, potassium, ammonium and alkanolammonium salts thereof;

b) one or more non-ionic surfactants, selected from ethoxylated alkanolamides of fatty acids, ethoxylated fatty alcohols and ethoxylated alkylphenols;

c) one or more solvents selected from alcohols, glycols, glycol ethers and low molecular weight ketones;

d) minor components, such as perfumes, dyes and antifermentation agents, which do not impair the characteristics of the composition;

characterized by the fact that:

the concentration of total surfactants (a)+(b) is higher than 60%, preferably between 65 to 75%;

the concentration of the said solvents is comprised between 5 and 40%;

the ratio of anionic to non-ionic surfactants is comprised between 10:1 and 70:1;

the above composition being soluble in water in times ranging from 1 to 5 minutes and such as to confer to the final diluted detergent, containing from 10 to 30% of active agents (a)+(b), a pH in the range from 6.5 to 7.5.

2. A composition according to claim 1, further containing water-soluble high molecular weight oxy-ethylene homopolymers in concentrations of 0.005 to 3%, preferably 0.05 to 2%, with the purpose to increase the viscosity of the diluted product obtained from the concentrated composition.

3. A composition according to claim 1, wherein the anionic surfactants comprise either alkane-sulfonates alone or mixtures thereof with alkylethoxy sulfates in a ratio 100:0 to 40:60.

4. A composition according to claims 1 and 3, wherein the alkane-sulfonate has an alkylic chain length in the range C₁₀-_20'

5. A composition according to claims 1 and 3, wherein the alkylethoxy sulfate comprises sodium salts of alkylsulfates with a chain length in the range C₉-_18' particularly Cg-₁₅ or C₁₂-₁₈, condensed with 3 moles of ethylene oxide.

6. A composition according to claims 1 and 3 to 5, wherein the non-ionic surfactants comprise nonylphenol condensed with 9 moles of ethylene oxide, or C₉-₁₅ straight chain alcohols condensed with 7 moles of ethylene oxide or coconut monoethanolamide condensed with 2 moles of ethylene oxide.

7. A composition according to claims 1 and 3 to 6, wherein the total content of anionic and non-ionic surfactants is 70% or more.

8. A composition according to claims 1 and 3 to 7, wherein the solvents comprise methanol, or ethanol, or acetone, or the monomethylether or ethylene glycol.

9. A composition according to claim 1, having admixtured therein water-soluble oxyethylene homopolymers having a molecular weight in the range from 400,000 to 5,000,000.

10. A process for obtaining a diluted detergent composition with increased viscosity characterized by diluting the concentrated composition of claim 1 in water to a concentration of active agents (a)+(b) of from 10 to 30%, and adding separately, in a ratio of at least 1:20, to the said concentrated composition during the dilution step viscosity enhancing materials selected from polyacrylic acids in water emulsion in addition to suitable neutralizing agents; alkanolamides of fatty acids and electrolytes, particularly chlorides and sulfates of alkaline, alkaline-earth, and ammonium nature.

11. The process according to claim 10, wherein, the said viscosity-enhancing materials are polyacrylic acids, which are neutralized by adding basic materials, selected from alkaline hydrates, ammonium hydroxide and alkanolamines, to the concentrated composition.