WO2005116178A1

WO2005116178A1 - A process of producing dried granulated powders

Info

Publication number: WO2005116178A1
Application number: PCT/BR2004/000187
Authority: WO
Inventors: Henri Charles Favre
Original assignee: Bentonit União Nordeste Sa
Priority date: 2004-05-25
Filing date: 2004-10-01
Publication date: 2005-12-08
Also published as: BRPI0401830A

Abstract

The present invention relates to a process for producing dried granulated powders, which comprises performing the steps of grinding and pigmenting simultaneously and, optionally, incorporating actives into said powders. This process is especially suitable for preparing dried granulated powders for the making detergents, toilet soaps, soaps and softeners.

Description

Title: "A PROCESS OF PRODUCING DRIED GRANULATED POWDERS" The present invention relates to a process for producing dried granulated powders (DGP), which impart an improved visual aspect and physical properties to the final product. The thus obtained granules are especial- ly suitable for manufacturing detergents, soaps, toilet soaps and softeners. Description of the Prior Art By DGP it is understood the pure bentonites and its combinations any other clayey minerals, inorganic fillers, inorganic and organic salts, in combination with each other on the order of from 0 to 95% by weight, as long as the result of these compositions is self-granulating or granulable by means of agglomerating auxiliaries. Bentonites are clayey minerals having 75% or more of a mineral known as montmorilonite. More specifically, bentonites are hydrated hexagonal phylosilicates of aluminum and magnesium. Their generic chemical com- position is Si₈.AI(₄-x).θ₂o-(OH)₄.nH₂θ (Na, Mg, Ca)_x. Bentonites are especially known for exhibiting a high swelling index, swelling up to 25 times its initial volume when in the presence of water. Bentonites are widely employed in the manufacture of cleaning products such as detergents, soaps and toilet soaps, cosmetics, paints and varnishes, sanitary granulates, ceramics, among others. Processes of producing DGP from ores by employing the steps of grinding and pigmenting are well known in the art. The grinding basically comprises addition of particulate mineral to a means that causes shearing forces, such as a mill, enabling the reduction in size of the particulate materi- al, in the presence or substantial absence of a solvent. The pigmentation of a particulate material generally comprises adding the particulate material to be pigmented, pigments, solvent and optionally additives to a mixing tank maintained under stirring until the desired point of covering and incorporation of actives is reached. In this regard, the quality of the product is generally the pivot for advances of these techniques. Constant improvements of equipment and process steps that enable, for instance, the reduction of periods of operation time and the increase in efficiency of the process have also been developed for the purpose of improving the production. Conventionally, the processes for obtaining DGP that involve the steps of pigmenting and grinding are carried out in sequence and in a batch regime. We can cite, for example, the systems of the Conimix, Ribbon Blender and Galgas type, which comprise previously mixing ingredients such as the material to be ground, pigments, water and actives, this mixture being subjected to grinding later. Thus, in order to obtain a pigmented and ground DGP, it is neecessary at least two separate pieces of equipment, such as a vessel and a mill, for carrying out the operations of pigmenting and grinding. These operations, however, when carried out sequentially, do not result in satisfactory homogeneity of coloration, incorporation of actives and reproductibility of the final product. It has been found that the drawbacks of the prior art may be o- vercome by means of a process of producing DGP wherein the steps of pigmenting and grinding the particulate material are simultaneously carried out under precise control of the addition of actives. These characteristics make the process extremely efficient, so much so that it may be carried out in a continuous way, with a reduced consumption of time and energy. Objectives of the Invention An objective of the present invention is to provide homogeneously pigmented dried granulated powders (DGP), providing an improved visual effect, optionally containing actives to impart improved physical properties and reproductibility of the final product. Another objective of the invention is to provide a process that enables to obtain dried granulated powders as described above. Detailed Description of the Invention The present invention relates to a process of producing dried granulated powders (DGP), which comprises at least the steps of extracting ore, crushing, grinding, pigmentation and granulation, wherein the pigmenting step is carried out simultaneously with the grinding step. The pigmentation is made by applying a pigment composition onto the DGP. The preferred pigment composition for carrying out the present invention comprises, for each 100 parts of the composition: about 10 to about 20 parts of a vehicle; - about 0.1 to about 1 part of the dyeing component; and optionally about 80 to about 90 parts of an active agent; Optionally, additives may be added to the composition for providing additional properties. The pigment composition has the function, in the context of the present invention, of providing dyeing to the DGP and optionally incorporating active ingredients, in order to improve the properties of interest of the DGP. The solvent may be nay organic or inorganic liquid inert to any ingredient of said composition, be it of high or low volatility, and with such a viscosity that it will not interfere with the movement of the grinding devices. Preferably, water is used as a solvent. The coloring component has the function of dyeing the substrate and may be pigments and/or dyes. The pigments may be either organic or inorganic. The dyes may be selected from acidic and alkaline ones. They may be either synthetic or natural. The active agent imparts a specific property to the DGP, according to their final use. In principle, any powdered solid or liquids that do not interfere with the agglomerating property (granulating step) may be added. The active agent may comprise one or more of the following: optical bleachers, essences, buffers, glycerin, dispersants, anti-foaming agents, moiste- ners, anti-settling agents, pouring aids, silicone, among others. The pigment composition may be in the form of a suspension, dispersion, emulsion or solution. Preferably, it is in the form of an aqueous suspension or solution. A process for preparing an aqueous suspension or solution of the pigment composition basically comprises adding its components, either si- multaneously or successively, to a mixing tank provided with a mechanical stirrer, which are maintained under stirring until the mixture has been homogenized. The DGP to be ground preferably have an input particle diame- ter of about 5 cm, and preferably they reach an output particle size of about 75 microns. The DGP initially stored in a container such as a silo, and the pigment composition are simultaneously fed to a mill in a controlled manner. The ratio between the flow rate of the DGP and the pigment composition fed to the mill will evidently depend upon several factors, such as diameter of the DGP, moisture contents of the DGP, type of mill, concentration of the pigment composition, the desired incorporation, type of active, and interaction between all the ingredients employed. The system is provided with set point in order to balance the variables of final interest. The DGP flow towards the mill through a tubing comprising a rotary valve. On the other hand, the pigment composition is fed to it by pumping, preferably by means of a precision pump such as a dosing pump, for subsequent application onto the DGP fed to the mill. Said application is preferably carried out by atomization. The flow rates of DGP and of the pigment composition are controlled by a solenoid valve, which actuates the rotary valve to the effect of increasing or reducing the flow rate of DGP, in order to correct possible oscillations that exceed the specified limits of the process and that, consequently, sends a signal to the pump to adjust the flow rate of the composition as a function of the variation of the flow rate of the DGP. It is important to note that such an arrangement enables an excellent control over the flow rates of DGP and pigment composition, bring about a precise incorporation of pigments and actives in the DGP. Additionally, it facilitates the change of feed of pigment compositions in the production line, that is, the change of color that is in use. A wide variety of conditions, parameters and grinding equipment may be employed with the method of the present invention. Evidently, the selection of the process characteristics, such as determination of the homogeneity of coloration, incorporation of actives, force or energy sufficient to guarantee a percentage reduction of particles, residence time of the DGP, types and dimensions of the equipment, speed of particle drag, percentage of reduction of particle size of the material to be ground, operation pressure and temperature, is up to the person skilled in the art, who knows how to arrange these conditions in such a way that the specification of the final DGP will be reached. Various types of mills may be employed in the present invention. Some examples are: hammer mills, roller mills, disc mills, pin mills, the roller mil being the preferred one in this technique. As the DGP are ground, they are also pigmented. Specifically for the case of a roller mill, the rising drag movement and dynamic sorting promotes the continuous separation of the DGP properly pigmented, which are stored for a subsequent step, such as granulation. The DGP of bigger particle size than of that of interest return continuously to the grinding chamber to complete the process of incorporating the pigment and/or actives. The performance of the grinding and pigmenting operations, according to the above-described arrangement, brings about an intimate and controlled mixture between the DGPs and the coating composition, which promotes greater coloration homogeneity of the DGPs, and the consequent reproductibility of the final product. Optionally, the ground and pigmented DGP may further be subjected to a subsequent drying operation by aspersion, vaporization or free- zing in order to adjust the moisture contents. The grinding and pigmenting steps are preferably operated at ambient temperature and pressure. However, these parameters may vary, as long as no melting of the particulate material or volatilization of the solvent occurs. If heating is necessary, the control over the temperature may be ef- fected by means of a sleeve or by dipping into water bath, or else by electric resistance. The process is preferably operated in a continuous regime. Al- ternatively, the batch regime and semicontinuous regime may also be chosen. The process of producing DGP of the present invention is also suitable for other minerals, mixtures of clayey minerals with inorganic fillers or organic and inorganic salts, provided that they can self-granulate or be granulated with the help of agglomerating agents and that they will also bear a minimum of 4% of moisture without dissolving. The process of producing DGP of the present invention, carried out with the grinding and pigmentation operations in a single step, advanta- geously brings about an increase in efficiency of the process and reduction of costs. The process of producing DGP of the present invention is especially intended for making detergents, soaps, toilet soaps and softeners. However, it is suitable for any application where one wishes the use of a colored powder or granulate and/or addition of active products supported on a substrate. A preferred embodiment having been described, one should understand that the scope of the present invention embraces other possible variations, being limited only by the contents of the accompanying claims, which include the possible equivalents.

Claims

CLAIMS 1. A process of producing dried granulated powders which comprise at least the steps of extracting ore, crushing, grinding, pigmenting and granulating, characterized in that the pigmenting step is carried out simulta- neously with the grinding step. 2. A process according to claim 1 , characterized in that, in the grinding step, a composition comprising pigment and liquid or solid actives or mixtures thereof is added. 3. A process according to claim 2, characterized in that the com- position added in the grinding step comprises, for each 100 parts of the composition, from 10 to 20 parts of a suitable vehicle and from 0.1 to 1.0 part of a coloring material and from 80 to 90 parts of actives. 4. A process according to claim 1 or 2, characterized in that the joint grinding and pigmenting step is performed in a continuous regime. 5. A process according to claim 1 , 2 or 4, characterized in that it is carried out at ambient temperature and pressures. 6. A process according to claim 2, characterized in that the actives are optical bleachers, essences, buffers, glycerin, silicone or a combination thereof. 7. A process according to claim 1 or 2, characterized in that the grinding and pigmenting step is performed on a mil, the dried granulated powders and the pigment composition being fed into the mill in a controlled way. 8. A process according to claim 7, characterized in that the con- trol is made by means of a solenoid valve in the steps of feeding the dried granulated powders and the pigment composition into the mill. 9. A process according to claim 7 or 8, characterized in that the pigment composition is fed into the mill by atomization.