Surfactant thickened systems comprising microfibrous cellulose and methods of making same

ES 2 393 973 T3

DESCRIPTION

Thickened surfactant systems comprising microfibrous cellulose and methods for producing them

Background of the invention

Packaged products such as body cleansers, shampoos, dishwashing detergents, laundry detergents, and car detergents, among others, are often thickened using a high concentration of detergents, combining viscosity synergistic surfactants, or combining the detergents with small amounts. amounts of salts such as sodium salts. These formulations result in high viscosity products that appear rich and uniform, but have limitations in that they do not provide sufficient low shear viscosity for particle suspension. Such particulate materials may include aesthetic agents (decorative pearls, mother-of-pearl articles, gas bubbles, aromatic pearls, etc.) or active ingredients (insoluble enzymes, encapsulated active agents such as humectants, zeolites, exfoliating agents (for example alpha hydroxy acids). and / or glycol or polyethylene beds), vitamins (eg vitamin E), etc., or both.

Conventional thickeners and suspending aids such as xanthan gum, carboxymethylcellulose (CMC), hydroxyethylcellulose (HEC), hydroxypropylmethylcellulose (HPMC), and many types of polyacrylates do not work well in surfactant thickened systems and often lead to loss of transparency due to to turbidity, gelling and / or phase separation or lack of sufficient suspending properties. For example, xanthan gum imparts excellent suspending properties in certain body cleansing formulations with low surfactant thickening, but the gum often loses its suspending ability in highly surfactant thickening systems, usually resulting in a hazy, irregular appearance, and a grainy or lumpy texture. Cellulosic products (CMC, HEC, HPMC, etc.), as another example of conventional thickeners, provide an unreliable suspension and have significant limitations regarding compatibility with surfactants. Acrylate systems, however, do not always achieve a sufficient level of clarity, require high concentrations of polymer, and are not considered natural. The salts are often capable of increasing high shear viscosity in surfactant thickened systems, but do not impart long term suspensive ability.

It is currently desired in the consumer products industry to provide surfactant thickened clear systems with particulate matter suspended therein, as well as an adjunct to high surfactant content suspension systems in which many alternative thickener systems will not work.

It has been discovered that bacterially or otherwise derived microfibrous cellulose (MFC) can be used to obtain a suspension of surfactant thickened systems as well as in formulations with high concentrations of surfactant. It has also been discovered that MFC can be used for this purpose without or with co-agents. When using bacterially derived microfibrous cellulose, cellular debris must be removed resulting in clear solutions at typical usage levels.

Microfibrous cellulose is not affected by surfactant micelle development and maintains good suspension in these systems. Microfibrous cellulose is unique in its ability to function in these systems in large part because it disperses rather than solubilizes, thereby achieving the desired suspension properties in formulations that would otherwise exhibit cloudiness and / or precitation. which are often seen using alternative solubilized polymers.

Brief summary of the invention

Surfactant systems comprising microfibrous cellulose are disclosed. It is intended to include "surfactant systems" but is limited to surfactant thickened systems and high surfactant content systems. Microfibrous cellulose (MFC) includes MFC prepared by microbial fermentation or MFC prepared by mechanical destruction / alteration of cellulose fibers from cereal, wood or cotton. When using bacterially derived microcrystalline cellulose, debris must be removed, resulting in clear solutions at typical usage levels. The present invention uses surfactants to achieve a very thick (highly viscous) system at high shear rates with suspended particles using microcrystalline cellulose.

The surfactant concentration in these systems ranges from about 5% to about 50% (w / w active surfactant), the specific concentration depending on the product. Body washes typically contain from about 5% to about 15% (w / w); Dishwashing liquids typically contain from about 20% to about 40% (w / w) surfactant (40% being a

ES 2 393 973 T3 "ultra-concentrated" product), and laundry detergents typically contain from about 15% to about 50% (w / w) surfactant.

MFC is present at concentrations of about 0.05% to 1.0%, but the concentration will depend on the desired product. For example, while about 0.06% (w / w) MFC is preferred to suspend small alginate beads in a body wash preparation, about 0.075% is preferred to suspend air bubbles in a body wash preparation. Also, the MFC concentration will be adjusted appropriately if a highly transparent system is desired. Specifically, a highly clear body wash preparation can be achieved at about 5% to about 15% (w / w surfactant) with an MFC level of about 0.055 to about 0.25% (w / w active surfactant). .

The MFC can be present at 0.06%, 0.075%, or 0.09%.

The particles to be suspended can include aesthetic agents (decorative pearls, pearlescent elements, air bubbles, fragrant pearls, etc.) or active ingredients (insoluble enzymes, encapsulated active agents such as humectants, zeolites, exfoliating agents (for example acids alpha hydroxylics and / or glycolics or polyethylene beads), vitamins (eg vitamin E) etc., or both One skilled in the art will identify other suitable particulate materials.

Microcrystalline cellulose blends are microfibrous cellulose products that contain coagents. Two mixtures are described which are MFC, guar gum and CMC in a 6: 3: 1 ratio, and MFC, guar gum and CMC in a 3: 1: 1 ratio. These mixtures allow MFC to be prepared as a dry product that can be "activated" by high shear or highly extensive mixing in water or other water-based solutions. "Activation" occurs when MFC mixtures are added to water and co-agents / co-processing agents are hydrated. After hydration of the co-agents / co-processing agents, high shear is generally required to effectively disperse the microfibrous cellulose fibers to produce a network exhibiting a true yield strength. Unexpectedly, the co-agent and / or co-processing agents CMC, xanthan, and / or guar gum present in these microfibrous cellulose mixtures appear to be solubilized (after activation in water) in many high surfactant formulations despite their incompatibility. in high surfactant systems, most likely due to the low level of use of these polymers in these MFC formulations.

The invention is further directed to processes for producing the disclosed surfactant systems.

The invention is also directed to a process for preparing a surfactant system which comprises combining a microfibrous cellulose with water and mixing, adding surfactant, and then mixing, adding particulate material, then mixing, wherein the resulting system is transparent and the particles are in suspension.

Brief description of the different views of the drawings

The above summary will be better understood when read with the Detailed Description of the Invention and Figures 1-

4.

Detailed description of the invention

Examples 1 and 2 describe body cleansing formulations demonstrating surfactant thickening properties and suspending properties using a 0.125% MFC / xanthan / CMC (6: 3: 1) mixture. Body cleansing preparations have very good clarity and the ability to hold air bubbles and beads in suspension.

Also described are manual dishwashing liquid and liquid laundry detergents, which have a higher surfactant level than that found in body wash preparations. Suspended alginate manual dishwashing liquids are described in Example 3.

In Example 4 a liquid laundry detergent with suspended fragrance beads is described.

In Example 5 a microfibrous cellulose in wet cake form was used to prepare a high surfactant system comprising a thick concentrated casting liquid with air bubbles in suspension.

Example 1

A liquid body wash formulation was prepared. Fig. 1 presents the clarity and suspending properties of this system. The resulting preparation exhibited a very thick surfactant rheology based on

ES 2 393 973 T3 visual inspection and had the ability to suspend air bubbles. With a slip value of approximately 3.4 Pa (measured with a Brookfield® slip rheometer).

Step A: Deionized water, 10% NaCl solution, and Kathon® CG were added to a small pitcher of Oster® Mix. Microfibrous cellulose (MFC / xanthan / CMC mixture 6: 3: 1) was added on top of the water and then the Oster® mixing blade was mounted and mixed at maximum speed for 5 minutes (liquefaction speed).

Step B: The contents were transferred to a 400 ml tall beaker with paint mixing blade. Sodium laureth sulfate (JEELATE® ES-3) was added to the solution described in Step A and mixed for 5 minutes at approximately 1000 rpm. Cocamidopropyl betaine sodium (JEETERIC® CAB-LC) was then added to the mixture and mixed further for 5 minutes at 1000 rpm. Fragrance agent was then added.

Step C: Cocamide DEA was added to the solution described in Step B. Thickening occurred as more DEA was added. Citric acid was then added as a 50% solution to lower the pH to the desired level (pH 5.5 in this case). The contents of the mixer were removed. Entrapped air during mixing was stabilized by the presence of the 6: 3: 1 MFC / xanthan / CMC mixture.

Table 1: Shower gel for body wash

<td>Stage of process</td><td>Ingredient</td><td>% (p / p)</td><td>Grams</td>

<td>TO</td><td>Deionized water</td><td> 54,775</td><td> 219,10</td>

<td></td><td>Microfiber cellulose blend</td><td> 0,125</td><td> 0,50</td>

<td></td><td>(MFC / xanthan / CMC mix 6: 3: 1</td><td></td><td></td>

<td>TO</td><td>10% NaCl solution</td><td> 5,00</td><td> 20,00</td>

<td>TO</td><td>Kathon CG</td><td> 0,10</td><td> 0,40</td>

<td>B</td><td>Jeeteric® CAB-LC cocamidopropyl- sodium betaine</td><td> 7,00</td><td> 28,00</td>

<td>B</td><td>Jeelate® ES Sodium Laurethsulfate</td><td> 25,00</td><td> 100,00</td>

<td>B</td><td>Fragrance</td><td> 1,00</td><td> 4,00</td>

<td>C</td><td>Cocamide DEA</td><td> 7,00</td><td> 28,00</td>

<td>C</td><td>Citric acid (50% solution)</td><td>the necessary</td><td>necessary</td>

<td>Totals</td><td></td><td> 100,00</td><td> 400,00</td>

Example 2

A body wash preparation was prepared as described in Example 1, but the bead suspension was incorporated instead of air bubbles. At the end of Step C, alginate beads were added. A visual representation of this embodiment can be seen in Fig. 2.

Example 3

High surfactant systems were prepared using manual dishwashing liquid and laundry detergent. Alginate beads were then suspended in the solution. Thick dish stock was diluted in half

ES 2 393 973 T3

Palmolive Ultra® for a thick broth for normal strength dishes. First, a concentrate was prepared containing 0.25% microfibrous cellulose mixture 6: 3: 1 mixture of MFC / xanthan / CMC in deionized water. The concentrate was made by mixing the solution in an Oster® mixer "on liquefaction" (maximum speed) for 5 minutes. The microfibrous cellulose mixture (Palmolive® contained 0.1% triclosan) was then diluted 1: 1 with Palmolive Ultra® detergent using a paint mixer or propellant blade. The thick dish broth was added to the microfibrous cellulose solution while mixing. Excellent clarity and suspension of air and / or alginate beads were achieved in both the Palmolive Ultra ® detergent and Dawn Ultra® detergent samples. The microfibrous cellulose was well diluted despite the relatively low shear of the mixer blade. The slip limit of these solutions was approximately 2.5 Pa. A visual representation can be found in Fig. 3

Example 4

A high surfactant system was prepared using a concentrated liquid laundry soap. "All Small and Mightly® three times concentrated" detergent was used. A 0.25% microfibrous cellulose mix concentrate (6: 3: 1 mix) of MFC / xanthan / CMC) was activated in distilled water with an Oster® mixer at full speed (liquefaction). The time was 5 minutes. The microfibrous cellulose solution was diluted 1: 1 with "All Small and Mightly® concentrated three times" detergent. The resulting dilution exhibited very good transparency and suspending capacity at a slip point of 0.62 Pa. Detergents were placed in an oven at 45 ° C to estimate heat stability and revealed excellent stability without loss of transparency or capacity. of suspension throughout 4 weeks of aging. A visual representation can be seen in Fig. 4.

Comparative examples

A high surfactant system was prepared using a concentrated liquid laundry soap using the microfibrous cellulose wet cake version. "All Small and Mightly® three times concentrated" detergent was used. A 1.56% wet cake microfibrous cellulose concentrate was activated in distilled water with an Oster® mixer at full speed (liquefaction). Mixing time was 5 minutes. The activity (% solids) of this cake MFC was approximately 16% so the level of active MFC was approximately 0.25% in the concentrate. The microfibrous cellulose solution was diluted 1: 1 with "All Small and Mightly® concentrated three times" detergent. A very good suspension was achieved for the resulting dilution at a slip point of 13 Pa. A visual representation can be seen in Fig. 5.