MXPA00008130A - Surfactants for structuring non-aqueous liquid compositions - Google Patents

Abstract

A surfactant system capable of structuring a non-aqueous liquid composition, wherein the surfactant system comprises at least about 5%of a structuring particle. The surfactant system preferably further comprises a surfactant selected from the group consisting of anionic, nonionic, cationic, amphoteric surfactants and mixtures thereof. A well dispersed mixture of a non-aqueous liquid, for example, a nonionic surfactant, and at least about 25%by weight of the surfactant system results in the mixture having a yield of at least about 2.0 Pa when measured at 20sec-1 and 25°C. Moreover, the surfactant system should exhibit a peak when measured by SAXS x-ray diffraction, wherein the peak's center is between about the 1.5 to 2.5v positions on the 2 theta axis. The structuring particles are most preferably structuring particles of sulfate and linear alkyl benzene sulfonate. Also provided is a method of making the structuring particle.

Description

SURGICAL AGENTS FOR STRUCTURING NON-AQUEOUS LIQUID COMPOSITIONS TECHNICAL FIELD This invention is in the field of structuring particles. Specifically, surfactant systems comprising a sufficient concentration of a surfactant that can structure a non-aqueous liquid.

BACKGROUND OF THE INVENTION Structured liquids, for example, gels and certain non-Newtonian fluids, have numerous applications and have gained great preference among consumers. For example, many paints are supplied as liquids that are structured in situ, that is, the structure is established in the container as the paint is mixed. The paint is typically structured in an attempt to uniformly suspend fine and solid ent particles in the liquid vehicle of the paint. But as most consumers of paint products know well, often when they buy the paint the ent particles have settled on the bottom of the container. This occurs when the structure of the paint is destroyed by normal agitation during shipping and handling of the paint in the container. Once the structure is destroyed it can not be restored, and the paint must be shaken or stirred before each use to re-suspend the ent particles. The need to shake or stir, which is often a dirty procedure, is the hassle of painting. Among the most common structurants for liquid compositions are clay compounds. Although clay provides good in situ structuring for certain liquid environments, structured clay systems are inherently unstable. Structured liquids with clay and other conventional structurants depend on a delicate balance of particle forces that, when altered, cause the structure to be destroyed. Specifically, two particles are often attracted due to natural forces such as van der Waals forces. But if two particles get too close together they will repel one another because of the natural repulsion forces between particles. Likewise, entropy works to destroy weakly structured systems. Consequently, structured liquids are fragile and the structure is easily destroyed. Conventional surfactants have also been used to structure liquids. But the structures of surfactants are inherently weak because they depend on a weak order of the surfactant molecules. More specifically, it is known that the surfactant molecules are disposed to themselves where the main groups agglomerate into micelles or reverse micelles, which can act individually as structuring bodies. Unfortunately, as is the case with liquids structured with clay, the structure depends on relatively weak intermolecular attraction forces, rather than actual chemical or physical binding. Liquids structured with conventional surfactants are generally unstable. In addition, the structure within a liquid can be destroyed by the addition of chemicals that adversely affect the forces between particles. For example, liquids structured with clay, surfactants or polymers are sensitive to the electrolyte composition of the liquid. Unfortunately, electrolytes are convenient for use in many liquid compositions such as heavy-duty liquid laundry detergents, which makes the structuring of these liquids especially difficult. Often the instability problems of structured heavy duty liquid detergent compositions are solved by maintaining very stringent controls over the formulation of these detergents, and using less than the amount of certain chemicals that would be sorted only by performance. In other words, the characteristics of performance and economy are often sacrificed to achieve the aesthetics of the desired liquid. These and other problems are solved by the structuring particles of the present invention. The problems related to fluid structuring mentioned above occur in non-aqueous solutions, for example, oil-based paint, as well as aqueous systems. However, the present invention is directed primarily to structuring non-aqueous liquids. To solve the problems and deficiencies of available liquid structurants there is a continuing need for new compositions that can produce relatively stable structured liquids. In addition, there is a need for a liquid structurant that is relatively insensitive to the chemical composition of the liquid being structured, and is tolerant of normal physical agitation.

BRIEF DESCRIPTION OF THE INVENTION The present invention provides a surfactant system capable of structuring a non-aqueous liquid composition, wherein the surfactant system comprises at least about 5% by weight of a radically structured particle. The surfactant system preferably further comprises a surfactant selected from the group consisting of anionic, nonionic, cationic, amphoteric surfactants and mixtures thereof. In a preferred embodiment of the present invention, there is provided a well dispersed mixture of at least about 25% by weight of the surfactant system and an alcoholic ethoxylate of C? 2-13 with an average degree of ethoxylation of 5, which gives as a result the mixture having a yield of at least about 2.0 Pa when measured at 20sec. "1 and 25 ° C. In another preferred embodiment of this invention, the surfactant system and the structuring particles present a peak when measured by SAXS x-ray diffraction, and the center of the peak is between approximately positions 1.5 to 2.5 of the 2-theta axis The structuring particles are preferably not soluble in non-aqueous liquids such as butoxypropoxypropanol, cyclohexane, nonionic surfactants and mixtures thereof Also, the structuring particles are preferably soluble in aqueous liquids In a preferred embodiment of the present invention The radically structured particle is a particle comprising sulfate and a surfactant comprising a sulfonate master group, and most preferably the structuring particle comprises C6-20 linear alkyl benzene sulfonate and sulfonate. In another aspect of the present invention, provides a method to make a radically structured particle. The method comprises the following steps: a) making a surfactant paste comprising an alkali metal surfactant, preferably sodium linear alkyl benzene sulphonate, and an aqueous solution, which is preferably water, in a ratio of about 2: 1 to about 1: 4, preferably from about 1: 1 to about 1: 3; b) combining the paste and an alkali metal sulfate, preferably sodium sulfate, in a ratio of metal surfactant to metal sulfate of from about 4: 1 to about 1: 2, preferably about 3: 1 at about 1: 1; c) stir the metal paste and sulphate until a well dispersed mixture is obtained; d) allowing the well dispersed mixture to stand without agitation for at least about two hours, preferably at least about 6 hours and most preferably at least about 12 hours; and e) drying the well dispersed mixture, preferably in a drum dryer. Surprisingly, it has been determined that the surfactant and structuring particle systems of this invention can structure non-aqueous solutions in the presence of numerous chemical compositions that can destroy conventional liquid structures. The ability to structure a variety of different non-aqueous solutions allows the surfactant system and structuring particles of this invention to be useful in numerous commercial liquid compositions, for example, for suspending particles in a liquid environment. Paint products, agricultural products and liquid laundry compositions are just some of the commercial applications for the structurants of the present invention. In the painting area, a secondary benefit is obtained by using the surfactant and structuring particle systems of this invention. Because the structurant can also be a surfactant, it is easier to remove the paint from the brushes and rollers due to the natural surfactant condition of the paint / surfactant combination. In addition to its ability to structure non-aqueous liquids, the surfactant systems and structuring particles of this invention have shown superior and unexpected dissolution properties in aqueous solutions. For example, the conventional linear alkyl benzene sulfonate is dissolved in water at a remarkably slower rate and to a lesser degree than a surfactant system comprising conventional linear alkyl benzene sulfonate and at least about 5% sulfate and sulfonate structuring particles of linear alkylbenzene, that is, at least about 5% of a structuring particle, according to the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS Although the specification concludes with the claims defining this invention with particularity, it is believed that this invention will be better understood with reference to the following detailed description and with reference to the drawings wherein: Figure 1 is a schematic representation of a possible configuration of the structuring particles of the present invention; Figure 2 is a graph of performance values for certain mixtures of surfactant systems, both conventional and in accordance with the present invention, as non-aqueous liquids; Figure 3 is a graphical representation of x-ray diffraction patterns for conventional surfactants and certain structuring particles according to this invention; and Figure 4 is a graphic representation of x-ray diffraction patterns for two mixtures; a conventional surfactant and a non-aqueous liquid, and structuring particles of this invention and a non-aqueous liquid.

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a surfactant system capable of structuring a non-aqueous liquid composition, wherein the surfactant system comprises at least about 5%, preferably at least about 6%, most preferably at least about 8%, and very preferably at least about 10% of a structuring particle that is essentially insoluble in non-aqueous liquids. The structuring particle preferably comprises a surfactant selected from the group consisting of anionic, nonionic, cationic, amphoteric surfactants and mixtures thereof. The surfactant system preferably further comprises a surfactant selected from the group consisting of anionic, nonionic, cationic, amphoteric surfactants and mixtures thereof. As used herein, the term "structuring particle" means any materials in the form of particles that are insoluble in a non-aqueous liquid, and can structure the same. That is, when the "structuring particles" of this invention are mixed with a non-aqueous liquid the mixture must have a performance value as defined below, and / or exhibit certain x-ray diffraction patterns as defined below. "Essentially insoluble in a non-aqueous liquid" means that less than about 10%, preferably less than about 5% and most preferably less than about 2% of the structuring particles of this invention are dissolved in non-aqueous liquids such as butoxyproxypropanol, cyclohexane , nonionic surfactants and mixtures thereof. As used herein the term "non-aqueous" means any liquid or solution comprising less than about 5% water, preferably less than about 2% water, and most preferably less than about 1% water, all the percentages are by weight. As used herein "well dispersed" means that there are no agglomerations of surfactant or other materials in the mixture that are visible to the naked eye.

All concentrations reported herein are by weight unless otherwise specified. While not wishing to be bound by theory, it is believed that when certain surfactants are processed under certain conditions in the presence of other chemicals, eg, sulfate, "particles" are formed which comprise ordered or adsorbed dispositions of the surfactant molecules. in flakes or sulphate crys. Figure 1 illustrates said ordered arrangement of linear alkyl sodium benzene sulfonate around a cry of sodium sulfate. It is believed that the sulfonate linear alkylbenzene sulfonate main group is attracted to the sulfate crys as shown in Figure 1. Synchrotron studies of structuring particles according to this invention are consistent with the model illustrated in Figure 1. When A sulphate cry is essentially "coated" with the sulfonate main groups, as shown in Figure 1, the resulting "particles" become essentially insoluble in non-aqueous liquids. Due to the composition of the particles, and possibly due to their shape, the particles of this invention form excellent structures in non-aqueous liquids, as modeled in Figure 1. The structure formed in a non-aqueous liquid by the structuring particles of this invention seems to be a spatial stabilization of the undissolved particles. That is, the structure depends mainly on mechanical forces instead of weak forces of charge between particles or hydrogen bond between molecules or particles. Therefore, liquids structured with the structuring particles of this invention are especially adaptable to changes in solution chemistry. An additional benefit of the particle arrangement of the structuring particles of this invention is that they dissolve more completely and rapidly in aqueous solutions than comparable surfactants. Although the present invention is directed primarily to structuring non-aqueous liquids, the additional benefit of superior and unexpected dissolution properties of the structuring particles herein also has many commercial applications. Many surfactants will form the structuring particles of this invention, but especially preferred surfactants for use herein are those with sulfonate major groups. As mentioned above, and as schematically shown in Figure 1, the structuring particles of this invention can be formed by attaching the main group of surfactant to a crystal. The sulfonate groups have an affinity with sulfate crystals which results in an exceptionally stable structuring particle according to the present invention. It is preferred that the non-structuring surfactant of the surfactant systems of this invention be soluble in the non-aqueous liquid to be structured. It has been determined that if a surfactant system according to the present invention, which comprises a surfactant and structuring particles according to this invention, is added to a non-aqueous liquid and the surfactant is not soluble in the liquid it does not watery, the structuring of thinning by high shear will usually not occur. It is believed that the undissolved surfactant inhibits the structuring properties of the structuring particles, or that the surfactant simply inhibits the dispersion of the structuring particles in the non-aqueous liquid. Regardless of the mechanism, it is generally preferred that the surfactant in the surfactant systems of this invention be soluble in the non-aqueous liquids to be structured. Again, the structuring particles of the present invention must be insoluble in the non-aqueous liquid matrices that are being structured. Although the present invention is described in terms of specific examples and compositions, it is not intended to limit the present invention in this way. The linear alkyl benzene sulphonate is used throughout this description as an example of a surfactant, and a C6-2o linear alkylbenzene sulfate and sulfonate structuring particle is a preferred structuring particle as defined herein. But it is intended that the scope of the present invention include all the structuring particles that fall within the performance measurements and x-ray diffraction patterns as defined below. Likewise, it is intended that all structuring particles made by the methods defined herein are within the scope of this invention.

Performance Measurements The structured liquids with the structuring particles of the present invention are typically non-Newtonian shear thinning fluids. Non-Newtonian shear thinning fluids are characterized as having higher performance values than unstructured Newtonian fluids, such as water. For example, a liquid that is a structured gel at rest, but is poured as a thin liquid similar to water, is typical of a non-Newtonian fluid of shear thinning. The force required to pour a structured gel can often be applied by simply tapping the bottle containing the structured gel material, where gravity acts on the fluid in the bottle providing enough force to overcome fluid performance. As mentioned below, the performance value is a measure of the force required to move a liquid from its resting position, or the force required to stop a moving fluid. A method for characterizing the ability of the structuring particles of this invention to structure liquids is by the use of performance measurements. Performance is defined as the value of shear stress (Pa) at which the geometry stops moving, that is, the lowest voltage necessary to move a sample. Performance measurements for liquid mixtures comprising structuring particles of this invention were taken and compared with the same measurements for liquid mixtures with little or no structuring particle. Figure 2 represents the results of a comparative measurement. The tested compositions and test conditions that resulted in the data marked in Figure 2 are given in Example 1 below. In summary, Figure 2 shows a bell-shaped curve with a peak yield value of about 5 to 6 Pa. All of the compositions tested in Figure 2 are linear alkyl benzene sulfonate dissolved in butoxypropoxypropanol and nonionic surfactant, as is defined in example 1. The amount of linear alkylbenzene sulfonate structuring in each sample varied based on the ratio of linear alkylbenzene sulfonate to sodium sulfate during the processing of surfactant. It is important to note that commercial suppliers of linear alkyl benzene sulfonate operate at a high ratio of linear alkyl benzene sulphonate to sodium sulfate, which results in linear alkyl benzene sulfonate with a low yield value, that is, below about 1 Pa in Figure 2. For purposes of this invention, when at least about 25%, preferably about 27%, and most preferably about 30% by weight of the surfactant systems of this invention are mixed with a non-liquid aqueous, for example butoxypropoxypropanol, cyclohexane, nonionic surfactants and mixtures thereof, the resulting mixture has a yield of at least about 2.0 Pa, preferably at least about 3.0 Pa, and most preferably at least about 4.0 Pa when measured at 20sec "1 and 25 ° C. Most preferably, the mixtures defined above comprise the agent systems surfactant of this invention and an alcoholic ethoxylate of C? 2-13 with an average degree of ethoxylation of 5. When at least about 1%, preferably at least about 3.0%, and most preferably about 5.0% by weight of the structuring particles of this invention are mixed with a non-aqueous liquid, for example butoxypropoxypropanol, cyclohexane, nonionic surfactants and mixtures thereof, the resulting mixture has a yield of at least about 2.0 Pa, preferably at least about 3.0 Pa, and most preferably about 4.0 Pa when measured at 20sec "1 and 25 ° C. Very preferably, the mixtures defined above comprise the structuring particles of this invention and an alcoholic ethoxylate of C? 2-? 3 with an average degree of ethoxylation of 5. Mixtures of a non-aqueous liquid and either the surfactant systems or defined structuring particles. previously they should be able to suspend particulate material that varies in size from approximately 0.1 to 1500 microns. Although a variety of particles are contemplated for use in the structured liquids of this invention, the preferred particles are selected from the group consisting of pigments, peroxygen bleaching agents, bleach activators, color spots, organic builders, sources of inorganic alkalinity and mixtures thereof.

X-ray diffraction Another method for identifying the structuring particles of this invention is through the use of x-ray diffraction. X-ray diffraction techniques are well known to those skilled in the art and these techniques are conventional methods for characterizing the structure of liquids and solids. In the example 2 that appears later, a detailed description of a SAXS x-ray measurement example is reported. The surfactant systems and structuring particles of this invention must present a peak when measured by SAXS x-ray diffraction, where the peak center lies between approximately positions 1.5 to 2.5 on the 2 theta axis. The peak should be present regardless of whether the surfactant system or the structuring particles are analyzed dry or if they are mixed with a non-aqueous liquid, preferably butoxipropoxypropanol, before being analyzed by SAXS x-ray diffraction. The mixture of surfactant system or structuring particles with non-aqueous liquid should comprise at least about 50% by weight of the surfactant system or structuring particles. The SAXS measurements were performed on: dry flakes of the surfactant systems and the structuring particles of this invention; dry flakes of conventional surfactant systems; mixtures of non-aqueous liquids with conventional linear alkyl benzene sulfonate; and mixtures of non-aqueous liquids with the structuring particles of this invention. Figures 3 and 4 are graphs of data exemplifying these measurements, wherein Figure 3 represents the x-ray patterns for the dried flakes, and Figure 4 shows the patterns for the measurements of liquid mixtures. The structuring particles of this invention are evidenced by the peaks, where the center of the peak lies between approximately positions 1.5 to 2.5 of the axis 2 theta, see the three lower lines plotted in figure 3, and also see the highest line shown in Figure 4. The highest line in Figure 3 and the bottom line in Figure 4 represent the conventional linear alkylbenzene sulphonate containing few or no structuring particles. It is interesting to note that the peak, approximately the position 2.75 of the axis 2 theta of Figure 3, which is clearly evident in the upper line, is absent from the three lower lines. The absence of the peak at about 2.75 is another indication that the compositions of the present invention have a physical structure substantially different from conventional surfactant systems. Figure 4 demonstrates that the structuring particles of this invention are substantially insoluble in non-aqueous solutions. The lower line in Figure 4 represents the spectrum for a mixture of conventional linear alkylbenzene sulphonate, butoxypropoxypropanol and nonionic surfactant. The upper line in Figure 4 represents the spectrum for a linear alkylbenzene sulphonate mixture processed according to the present claims, that is, it comprises structuring particles, and butoxypropoxypropanol and nonionic surfactant. The top line of Figure 4 has a pronounced peak at approximately position 2 on the 2-theta axis, indicating the presence of undissolved structuring particles according to the present invention. The lower line plotted in Figure 4 has no peaks, which indicates that there are no structuring particles in the mixture, and that all the linear alkyl benzene sulfonate was dissolved in the non-aqueous liquid mixture. Using SAXS x-ray diffraction, the structuring particles of this invention exhibit a peak, where the center of the peak lies between approximately positions 1.5 to 2.5 on the 2-theta axis, preferably between approximately positions 1.6 to 2.2 on the axis 2 theta, and most preferably between approximately positions 1.7 to 2.0 on the 2 theta axis. Those skilled in the art know that a "peak" has a standard definition that depends on the noise level of the x-ray equipment. The intensity of a peak is not an indication of concentration of the structuring particles. However, at concentrations of less than about 5% by weight of structuring particles in a surfactant system, a peak between approximately positions 1.5 to 2.5 on the 2-theta axis is rarely visible due to limitations in the sensitivity of the equipment.

It is important to note that although a peak between the positions 1.5 to 2.5 on the 2-theta axis indicates the presence of structuring particles according to the present invention, the amount of the structuring particles must be determined by other methods, such as centrifugation. A method for determining the amount of structuring particles in a surfactant system, or in a mixture of structuring particles and non-aqueous liquid is defined in Example III below, other methods will be known to those skilled in the art.

EXAMPLES The following examples are intended to illustrate certain aspects of the present invention, but are not intended to limit the scope of this invention in any way. The following abbreviations are used in the following examples: "CLASS" = linear alkylbenzene sulfonate and sulfonate structuring particles, a "LAS" structuring particle = linear alkyl benzene sulfonate, non-structuring "BPP" = butoxipropoxypropanol EXAMPLE I Determination of performance values The following procedure is used to determine performance values for non-aqueous liquid mixtures and surfactant systems comprising a structuring particle. Table 1 below shows the performance and viscosity measurements for surfactant systems made in accordance with the present claims and conventional surfactants. The NaLAS: Na2SO4 ratio in the first column of Table 1 corresponds to the relationship in the claims of the method herein. 1. Dry flakes of a surfactant system comprising LAS and CLASS are dispersed in nonionic surfactant (Neodol 1-5 or Neodol 23-5), at 26.7% by weight LAS / CLASS, 73.3% by weight nonionic surfactant. The mixture is made with an IKA mixer until all LAS / CLASS is moistened. (The mixing time depends on the batch size, etc.). 2.- The LAS / CLASS / nonionic surfactant mixture is fed by gravity through a rotor / stator colloid mill set at 40 um. 3.- BPP is added to the LAS / CLASS / milled nonionic surfactant mixture to give: 9% LAS / CLASS, 48.8% Neodol 1-5, and 42.2% BPP, by weight. 4. - The BPP / LAS / CLASS / nonionic surfactant mixture is stirred at the minimum required speed to obtain adequate mixing for approximately 15 minutes. 5.- The rheology of the mixture, specifically the yield (Pa) and the viscosity (cps) is measured @ 20 1 / s, these values are used to determine the level of structure. 6.- The equipment and method used for rheology measurements are the following: Equipment: CarrieMed CSL2 Rheometer Geometry: 4 cm steel parallel plate Separation adjustment: 500um - 200um Temperature: 25 ° C Method: Previous shear stress: 125 1 / s constant shear rate for 2 minutes. Curve down: Continuous inclination, controlled tension @ 50 Pascals down to 0.1 Pascals with 3-minute tilt duration.

TABLE I * Nal_AS = LAS before processing EXAMPLE II SAXS Measurements SAXS measurements are made with a Rigaku-type Kratky camera using an infinite slot geometry. Cuka radiation filtered with Ni is produced using a Rigaku rotating anode device (12kW) operated at 40kV and 100mA. The dispersion patterns are collected with a sensitive proportional linear position detector (Braun OED-SOM). The calibration is obtained using the sixth order of a collagen oriented sample to determine the position of the primary beam, with respect to the channel number. Once this is achieved, all other peak positions, as noted by channel numbers, can be correlated with scattering angles, or s values. For example, a sixth order peak collagen peak position is 276.2 (x2), while a peak position for the primary beam is 138.6 (x-i). The corresponding value s for the peak of collagen of sixth order is 0.009375Á "1 (y2), and the corresponding value s for the primary beam is 0Á" 1 (yi). To calculate the values s the following equations are used: (y2-y?) * (? - ??) = (? Z - ??) * (yy?) Y = ((y2-y -?) * (X ~ x?) / (x2-x?)) + y? EXAMPLE III Determination of the amount of structuring particles The following method is for determining the amount of structuring particles in a surfactant system, or for determining the amount of structuring particles in a mixture comprising structuring particles and a non-aqueous liquid. The following BPP / LAS / CLASS / nonionic surfactant mixture is prepared: 9% LAS containing an unspecified amount of CLASS particles 42.2% BPP 48.8% nonionic surfactant (Neodol 1-5 or Neodol 23-5) ) It will be understood by those skilled in the art that 9% of LAS contains non-surfactant materials, including residual byproducts of the manufacturing process, and unreacted starting ingredients. These materials that are not surfactant are explained in the analytical method described below. In addition, in order to ensure that all the soluble material is dissolved in the non-aqueous liquid mixture, it is preferred that the amount of LAS tested is less than about 10%. At concentrations substantially greater than 10% the liquid mixture can be saturated and some soluble material could be centrifuged outward, producing an inflated reading for the amount of insoluble material. Again, this potential problem is avoided by keeping the test sample below about 10% by weight of the mixture. After the dispersion of LAS in the non-aqueous mixture, part of the mixture is centrifuged at 12000 rpm for 3 hours using a model centrifuge J2-21 of Beckman. The supernatant is overcome is separated from the centrifuge tube and, using conventional surfactant titration methods, the amount of LAS present in the supernatant is determined. A non-centrifuged sample, otherwise identical to the centrifuged sample, is also analyzed by conventional surfactant titration methods for the amount of LAS. The difference between the amount of LAS in the non-centrifuged sample and the amount of LAS in the supernatant of the centrifuged sample gives the amount of insoluble material, or CLASS particles, by weight, which was in the original centrifuged sample. The amount of CLASS, by weight, divided by the total weight of LAS in the centrifuged sample, determined by the titration of the non-centrifuged sample, produces the weight percentage of CLASS in the surfactant system.

EXAMPLE IV Preparation of LAS powder A preferred use for the structuring particles and surfactant systems of the present invention is in liquid non-aqueous heavy duty laundry detergent compositions. An example of such a surfactant system comprising structuring particles for use in non-aqueous liquid detergent compositions is provided below. Specifically, sodium linear C 12 alkylbenzene sulphonate (NaLAS) is processed into a powder containing two phases. One of these phases is soluble in the non-aqueous liquid detergent compositions herein and the other phase is insoluble. The insoluble fraction is the structuring particle, which adds structure capacity and suspension of particles to the non-aqueous phase of the compositions herein. A surfactant system in accordance with this invention is produced by taking a suspension of NaLAS (Pilot Chemical Co., Calsoft L-50) in water (approximately 40-50% active) combined with dissolved sodium sulfate (approximately 3-15%). active) and hydrotrope, sodium sulfosuccinate (approximately 1-3%). Hydrotrope and sulfate are used to improve the characteristics of dry powder. A drum dryer is used to dry the suspension in a flake. When NaLas is dried with sodium sulfate, two distinct phases are created within the flake. The insoluble phase creates a network structure of small aggregate particles (0.4-2 um) that allows the finished non-aqueous detergent composition to suspend the solids. The surfactant system prepared according to this example has the following composition shown in Table IV, A. TABLE IV, A System of surfactant * May include residual amounts of water, sulfate and other contaminants. A liquid non-aqueous detergent composition using a surfactant system according to the present invention is presented below.

TABLE IV. B Liquid composition of non-aqueous detergent with bleach The resulting table IV, B composition is a non-aqueous liquid detergent for stable heavy duty washing that provides excellent soil and dirt removal performance.

Claims (7)

NOVELTY OF THE INVENTION CLAIMS

1. A surfactant system capable of structuring a non-aqueous liquid composition, characterized in that the surfactant system comprises at least 5%, preferably at least 6%, most preferably at least 10% of a structuring particle that is substantially insoluble in liquids not watery

2. The surfactant system according to claim 1, further characterized by a surfactant selected from the group consisting of anionic, nonionic, cationic, amphoteric surfactants and mixtures thereof.

3. The surfactant system according to claim 1, further characterized in that a well dispersed mixture of at least 25%, preferably at least 30% by weight of the surfactant system and an alcoholic ethoxylate of C? 2- 3 with an average degree of ethoxylation of 5, results in the mixture having a yield of at least 2.0 Pa, preferably at least 3.0 Pa, most preferably at least 4.0 Pa when measured at 20sec "1 and 25 ° C

4. The surfactant system according to claim 3, further characterized in that the mixture is capable of suspending material in the form of particles ranging in size from 0.1 to 1500 microns, and is selected from the group consisting of pigments, agents peroxygen bleach, bleach activators, color spots, organic builders, inorganic alkalinity sources and mixtures thereof

5. The surfactant system in accordance with the claim dication 1, further characterized in that the structuring particle comprises linear alkylbenzene sulfonate and sulfonate of C6-2o-

6. The surfactant system according to claim 1, further characterized in that the surfactant system has a peak when measured by SAXS x-ray diffraction, where the center of the peak lies between positions 1.5 to 2.5, preferably between positions 1.6 to 2.2, and most preferably between positions 1.7 to 2.0 on axis 2 theta.

7. A structuring particle made by a method comprising the following steps: a) making a surfactant paste characterized by an alkali metal surfactant and an aqueous solution in a weight ratio of 2: 1 to 1: 4; b) combining the paste and the alkali metal sulfate in a weight ratio of metal surfactant to metal sulfate of 4: 1 to 1: 2; c) stir the paste and metal sulphate until a well dispersed mixture is obtained; d) allowing the well dispersed mixture to stand without agitation for at least two hours; and e) drying the well dispersed mixture.