MXPA98003885A - It migration - Google Patents

Abstract

The present invention is for a process for producing a matrix particle of a dye lacquer or dye which matrix reduces the extraction or dripping of the dye lacquer or dye in the surrounding medium. The process of the present invention is particularly useful in toothpaste formulations

Description

MIGRATION OF DYE FIELD OF THE INVENTION Process by which dyes and dyes are prepared with a material to form dry particles that are impervious to water.

BACKGROUND OF THE INVENTION Water-soluble dyes are generally liquid, or soluble solids that are used in solution. The pigments are generally solid and are usually insoluble in the medium in which the pigment is being used. Water-soluble dyes have significant disadvantages when used in soaps and toothpastes, for example as those dyes that can stain skin and clothing and often complex with proteinaceous materials. In addition, as soap bars and toothpaste repeatedly come into contact with water, water-soluble dyes tend to move and stain the skin, bath tubs, etc. Pigments, therefore, are typically used in place of dyes in applications where migration of color or discoloration is undesirable. Various approaches have been proposed to reduce the discoloration or fouling of the dye lacquers or dyes to prevent color migration in the surrounding phases. These resulting products are used in household and toilet products such as soap, toothpaste and other cosmetics. The absorption of the lacquer in a medium, a colorless substrate of alumina, zirconia or titanium in this case, is taught in U.S. Patent 4,444,746. Alumina, zirconia or titania are used to absorb the pigment on their surfaces, which provides a means for color dispersion through the dentifrice medium, without dissolving the water-soluble dye. Water-insoluble pigments and the production thereof are described in U.S. Patent 4,769,080 in which the anion-layered exchange material is contacted with the dye under conditions in which an insoluble pigment is obtained in water. Water. The water-soluble dye and the anion-layered exchange material are contacted together in a liquid medium in which the dye has dissolved. The anion exchange material in layers is preferably a layered aluminate. GB Patent 1,319,991 discloses the preparation of color resins with non-toxic water soluble dyes as a waterproof interlaced synthetic resin for use in toothpastes. The polymerized resins that are used in this process have monomers that are soluble in water and can be polymerized to insoluble resins in an aqueous solution. The resins used in this description do not absorb an appreciable amount of water in the prolonged contact. Specifically, low molecular weight water soluble resins such as urea formaldehyde resins, melamine formaldehyde, melamine formaldehyde-urea and phenol formaldehyde are described. United States patents 4,129,638, 4,208,878 and GB 1,319,992 describe all the preparation of a pigment in an agglomerate form whereby the pigments are dispersed in molten wax, or a gelling agent which is then reduced in particle size to 200 to 500 microns. The pigment particles should be fast-colored and water-soluble dyes by themselves, and can not be used in this invention. However, the description teaches the use of thermosetting resin particles with fast color dyeing, as described in GB 1,319,991 above. U.S. Patent 4,069,311 describes the prior art processes by which the veins have been prepared by melting a physiologically acceptable organic binder, such as a thermoplastic resin, wax or high molecular weight ester, for example glyceral tristearate. This prior art method of converting the resulting particles, which is somewhat irregular in appearance and size, to particles in the range of 0.05 to 1 mm can be obtained through sieving or screening. To avoid irregular shape and sieving the patent teaches the use of high shear agitation of the veined material and a binder, such as thermoplastic resins, gums, paraffin gels, waxes, polymers and higher fatty acids and salts thereof, with dispersion of the molten mixture of the binder and the dye within a dispersion medium, such as water, thus forming small globules or particles when cooling. Another approach to using non-toxic water-soluble dyes is taught in U.S. Patent 4,533,484 in which the water-soluble pigments were produced by contacting the water-soluble dye with a polymer comprising an alkyl-2-oxazolidinone moiety. This resulted in a pigment particle having insolubility characteristics of the polymer and color characteristics of the dye. The pigmented polymer is prepared by contacting the polymer with an aqueous medium in which the polymer is at least partially soluble. For this solution, the dyes are added in excess. The temperature is high and a highly colored precipitate results that can be filtered or dried. The polymer dye produces a pigment that is insoluble in an aqueous liquid, at temperatures above 3 ° C. A pigment is generally insoluble in an aqueous medium under normal conditions of use. The prior art methods have failed in the production of a product, particularly a product having smaller particle size, which effectively prevents the migration of color into the surrounding medium. The present invention provides such a method as a commercially practicable and useful method wherein the prepared matrix particle is useful for any lacquer of a soluble dye that is left untreated would tend to be leached in water or other solvent.

BRIEF DESCRIPTION OF THE INVENTION The present invention is a process for producing a matrix particle of a lacquer with color or dye whose matrix reduces the leaching or discoloration of the lacquer with color or dye within the surrounding medium. Another aspect of the present invention is a matrix particle comprised of a substrate and a color or dye lacquer having a regular shape and whose ingredients are present in a ratio of 0.5 to 9% lacquer to the substrate (w / w). Another aspect of the present invention is use of the matrix particle in cosmetics and toiletries, or for use in tablet coatings, etc. , for pharmaceutical applications.

DETAILED DESCRIPTION OF THE INVENTION The present invention is a process for encapsulating colored lacquers within a substrate, such as high density polyethylene material, which forms particles that are substantially impervious to water, or other solutes of choice. This process results in significantly reduced dye migration of the material with color from the resulting matrix formulation. Optionally, a secondary coating of another substance, such as petrolatum-like material can be applied to the matrix particle, wherein migration of the dye is virtually eliminated in this way. Suitably, the substrate or encapsulation material is a high density polyethylene although, natural and synthetic waxes, such as Carnauba wax or microcrystalline wax (Mekon White ™ Wax) can be used. Other suitable polymers and waxes that have utility in this process include, but are not limited to, polyethylene of different densities, or oxidized hydrocarbon (such as Petronauba ™). To be used successfully as a substrate the agent must have a different melting point between about 80 ° C to about 130 ° C. It must be a relatively thin liquid in the molten state, and it must be capable of forming fine droplets when sprayed from a spray nozzle. It is preferably a solid at room temperature and liquefies without destruction upon heating. The material is preferably hydrophobic. The material is stable in water or other ingredients, such as flavorings, glycerin, sorbitol, surfactants and other materials such as are present in standard form in toothpastes or tabletting for pharmaceutical companies. The material is one that can be dispersed in suitable solutes or creams, etc. , which has been made inside a matrix particle with the appropriate lacquer. Finally, the material preferably has a "refined" solidification point, that is, highly defined. Preferably the encapsulation material is polyethylene, Carnauba Wax, or Mekon White ™. More preferably, it is a high density polyethylene material. A polyethylene used in the present invention, see Example 1, is Polywax "500 from Petrolite, which is considered a high density polyethylene, although it is not as high in density as the polyethylene used in a" Jet Mili "process, as described below in another example Polywax® 500 is a completely crystalline substance with a fine melting point of 86 to 88 ° C. As shown in example 2, the substrate polyethylene is Polywax "500 from Petrolite. In an alternative embodiment the substrate polyethylene such as Polywax® 2000 can be used, which substrate is completely melted at about 130 to 135 ° C, and have a specified melting point of about 126 ° C. As used herein, the term "dye" is an inorganic species that is essentially soluble in water in an aqueous medium, in which the dye remains chemically stable. In a suitable manner, this is a color designated as a Drug color. and Cosmetic (Drug and Cosmetic (D &C) color) or, is a lacquer as described in the Handbook of U. S. colorants for Foods, Drugs and Cosmetics, D. Marmion, Wilery-lnterscience Publication, the description of which is incorporated herein by reference therein, and is designated as a lacquer or color of Food, Drug and Cosmetic (FD &; C). Alternatively for use herein, mixtures of D &C dyes and FD &C lacquers may be employed. Preferably, the matrix particles are formed with colored lakes. Preferred lacquers include, but are not limited to, FD & C Blue No. 1, Blue No. 2, Green No. 3, Green No. 6, Red No. 3, Red No. 10, Red No. 30 , Yellow No. 5, Yellow No. 6, Yellow No. 7, Yellow No. 8, and Yellow No. 10. Suitable dyes and lacquers, their structures and properties for use herein are known to those skilled in the art. . Additional information can be obtained for example in Kirk-Othmer Encyclopedia of Chemical Technology, 3rd Edition, Volume 6, pg. 561 -596 whose description is incorporated by reference herein. Preferred lacquers include FD &C Blue Lacquer No. 1, FD &C Green Lacquer No. 3, and D &C Yellow Lacquer No. 10. In one embodiment of this invention the substrate-lacquer mixture is formed into a matrix particle by applying the spray freezing method. Spray freezing is an alternative to jet grinding and provides lower overall material cost, an intensive process of lower energy since grinding is not required to reduce the particle size of the resulting matrix and is a highly safe process for the environment and efficient. The resulting matrix particles produced by this process, which do not fall within the desired particle size, can simply be reused, or recycled, in the process. Consequently, there is no effluent, or wash that must be discarded. As is well known in the art, it is extremely difficult to avoid the migration of blue lacquers, which make them difficult to handle for commercial use. The present invention therefore provides an efficient, commercially practical and environmentally compatible process for the production of matrix particles, in particular blue matrix particles, whose particles have reduced discoloration or leachate in the surrounding medium. The resulting particles produced by this process are small and well encapsulated and do not require additional washing phase, as is necessary if a grinding step was required. The resulting particles also do not require grinding process to reduce their particle size. The desired particle size (2 to 65, preferably 5 to 40 microns) is determined by the combination of pumping speed, pressure and nozzle size as demonstrated herein. In the spray freeze, the hopper, the feed line and the nozzle in the spray dryer are preferably pre-heated. The atomization air pressure is preferably set between 2.46 kg / cm2 to 5.27 kg / cm2. The higher the atomization pressure, the finer the particle size. As a general rule, it is desirable to spray with the largest fluid cover and the highest possible air pressure and still be available to maintain a fine particle distribution and be within the cooling capacity of the dryer.

Fan (or flat) spray nozzles can also create fine particles. However, since this installation uses external mixing air layers, it is also susceptible to nozzle plugging due to the effects of expansion cooling. Round spray nozzles are considerably less prone to clogging although higher atomization pressures (3.86 to 5.27 kg / cm2) are generally required so that the round spray nozzle achieves a fine particle size. It is possible to produce particles that are so fine (less than 5 microns), using, for example, an ultrasonic nozzle. The smaller particle size, that is, the "ultrafine" particles, may require more dye to give a suitable color in the desired final product in which they are to be used. Encapsulated dyes of smaller particle size also have the tendency to migrate more, possibly due to the less effective encapsulation and greater surface area exposed. The flow velocity of the polyethylene dye mixture is controlled by the pumping speed, the size of the fluid cover in the spray nozzle and the amount of air atomization pressure. With the typical nozzle arrangement (installation # 4 of the sprinkler system, fluid cover 60100, air cover 120), at 5.27 kg / cm2, the optimum product flow rate is approximately 1.5 to 2.5 kg / hour. In a production facility, a spray speed of 30 to 90 kg / hour can be achieved. It is observed that while it is very useful, the process of freezing spray is not 100 percent effective. There is still a small percentage of dyes that are not on the surface or near the surface that can migrate over time. Therefore, depending on the circumstances and the end use, a secondary coating, also referred to as a barrier coating, may be necessary to completely eliminate dye migration. Barrier coatings are well known in the pharmaceutical art. Therefore, one skilled in the art would suitably use the Eudragit ™, HPMC or PVP coatings as a barrier coating. Suitable secondary coatings include, but are not limited to, Petrolatum, vegetable oil, coconut oil, mineral oil, dimethicone and pharmaceutical coatings (such as Ethyl Cellulose, or the Eudragit ™ coatings series). These coatings have been applied successfully on encapsulated polyethylene particles as a secondary coating. See example 3 for additional information. Preferably the coating agent is Petrolatum and mineral oil or dimethicone. Both Petrolatum and mineral oil are effective and also low cost. The DC Silicone FluidTM (Dow Corning) can effect foaming properties if used too much on certain items, such as a toothpaste. The use of the pharmaceutical coating, such as Eudragit ™ coatings, is less preferable as the cost increases and will equally require another spray drying step, or a fluidized bed coating step for such coatings. Generally, a preferred coating is made with about 15% matrix particles up to 85% petrolatum; 505 matrix particles up to 50% mineral oil and / or combinations of mineral oil and petrolatum with the matrix particles. Particle agglomeration in spray freezing can be a problem. In each lot made there is a small percentage (0.5% to 3%) of agglomerated particles in the 65-100 micron scale. Those large particles can be shown as streaks of dye in a final product, such as a gel. Preferably, those agglomerates are removed before being added to a final product that would be affected by their inclusion. A suitable means of removal is by the use of an air separator or filtration, mechanisms well known to those skilled in the art.

Color matching with encapsulated polyethylene dyes is more difficult than with soluble dyes. Starting with the same ratio of dye to polyethylene, the intensity and shade of color can change from one operation to another depending d? the process parameters. Process axis parameters such as the product feed rate, the flux cover type and the atomization pressure of the air, can be adjusted. final color of the 'M' encapsulated dye powder. For the same ratio of dye to polyethylene, the differences in color intensity and shadow can be attributed to the differences in the particle size distribution. The small particles (<5 microns) can also be removed with an air separator or by adjusting the air pressure during the manufacture of the dye. The lacquer to substrate ratio, such as polyethylene, is between about 0.5% up to about 9%, preferably 2% up to 6%. If the encapsulated lacquer is to be used "as is", that is, without a secondary coating, a lacquer to polyethylene ratio of 4% provides better encapsulation. If a second petrolatum coating is to be applied to the encapsulated particles then a higher lacquer to polyethylene ratio could be used. As noted below, it is possible to add more than one lacquer together with the substrate and then the spray freeze to obtain the desired final product. A drip homogenizer, or some other suitable high-strength mixer, is necessary to disperse the colored lacquer within the molten polyethylene. Any dye agglomerates need to be broken and dispersed within the polyethylene for good encapsulation. The temperature of the polyethylene-dye mixture is slowly increased to about 125 ° C and maintained at this temperature with constant stirring until the spray dryer is ready to receive the material.

The feed tank, the feed line and the nozzle on the spray dryer are preferably preheated. While this is not necessary in all cases, depending on the selected substrate is preferable for ease of manufacturing and cleaning. Once the equipment is preheated to 125-135 ° C, the polyethylene lacquer mixture is poured into the feed tank. The cooling air and the atomization air are activated and the spray freeze of the mixture is started. The atomization air pressure is set between 2.46 kg / cm2 to 5.25 kg / cm2. The flow velocity of the polyethylene dye mixture, with the typical nozzle arrangement, (installation of sprinkler system # 4, fluid cover 60100, fluid cover 120), at 5.25 kg / cm2, results in the measurement of product flow rate from 1.5 to 2.5 kg / hour. The pump speed of the Pilot Unit will generally vary from about 25 to about 40 ml / min, preferably from about 25 to about 30 ml / min. As the melted polyethylene dye mixture is atomized by the spray nozzle, fine spherical droplets form inside the cooling chamber. PlywaxR500 polyethylene, for example, has a solidification point very different from 86 ° C and should follow a typical solidification curve. Drops of polyethylene dye enter the cooling chamber at approximately 125 ° C. The drops are cooled to the solidification point (in this case) of approximately 86 ° C. The solidification takes place at a constant temperature that releases the heat of crystallization. After the particles solidify, freezing continues as the particles are discharged from the cooling chamber at about 40 ° C. The complete cooling-freezing-cooling cycle occurs in a matter of seconds. As noted above, the matrix particles produced herein may have application in cosmetics or toiletries, such as shower gels, mouthwashes, toothpaste or other dentifrices, for use in tablet coatings or to produce colored tablets when desired, i.e., pharmaceutical applications. A preferred use is in toothpaste, mouthwash, toothpaste or oral care. Incorporation of the matrix particles into the desired product, such as a toothpaste formulation can be used "as is", i.e., as a fine powder that can be dispersed with the surfactant already found in toothpaste formulations, such as as PEG 400, or it can be dispersed with a drip ho ogenizer or a colloid mill. The matrix particles, the PEG, and the gums can be added in a batch at the beginning of the batch process. The matrix particles can also be dispersed in sorbitol using a little sodium lauryl sulfate solution and a colloid mill. They can then be added in lower stage of lesser thickness at the end of the process. It can also be added with premixed flavor and added at the end of the batch.

When the matrix particles are coated with a secondary petrolatum coating the matrix particles are in the form of a colored paste. The colored paste can be added to the batch in the thickest stage after the thickener (eg, Zeofree) has been loaded into the batch. The dye paste can contain 15 to 25% particle matrix, 10 to 20% mineral oil and approximately 60 to 75% Petrolatum. If two separate matrix particles having different lacquer incorporation are used, the colored paste may have different% w / w of particles present to obtain the desired coloring effect. For example, the concentration of dyes can be 0.75% blue dye paste and 0.25% blue dye paste. It is recognized that there are some processing problems in the use of matrix particles as the fine powder form of the dye is very hydrophobic and does not easily disperse in a liquid medium. A lot of mixing energy is required to disperse the dye, either PEG400 or sorbitol. If too much heat is generated in the dispersion process (such as above 65 ° C) the polyethylene coating can become soft and agglomerate into large particles. The colloid mill used to disperse the dye is preferably cooled with ice water to keep the dispersion below 55 ° C. The paste form of the dye may also result in its own processing problems as it is hydrophobic and a mixer of sufficient shear stress may be necessary for the proper mixing.

Another embodiment of the present invention is the discovery that matrix particles produced by means other than spray freezing, as illustrated below, can be coated with a secondary coating as described herein and produce matrix particles. with substantially reduced discoloration. These particles can be produced using a suitable substrate, such as a high density polyethylene, with colored lacquers such as FD &C blue No. 1 lacquer or yellow D &C lacquer No. 10 and, grind to a fine powder, preferably 5 microns to 10 microns, preferably with a jet mill, although any available mechanism well known to one skilled in the art will suffice. The fine powder is then washed, removing any exposed dye as a result of grinding. Alternatively, the washing process can be eliminated, as the second petrolatum coating is applied to cover the surface that will seal any cracks for the coating. To form the matrix particle, the substrate material melts first. In the case of a high density polyethylene resin, at temperatures of approximately 107.2 ° C. the lacquer particles are stirred into the resin, so that the resulting mixture is homogeneous. Suitably, this is run with a drip homogenizer, although one skilled in the art can use any suitable well-known means. The mixture is poured onto a suitable surface, such as a metal tray and allowed to harden, preferably at room temperature. Once cooled, the dyed polyethylene breaks easily from the trays. The solidified mixture is broken into pieces small enough to be fed into the suitable mill, such as a Fitzmill, producing a coarse powder of a size of about 80 to 800 microns. The coarse powder is then fed into a jet mill to obtain particles of a size of about 5 microns to about 10 microns. Using water from the tap, or other aqueous product and filter pads, the particles are washed to remove any lacquer stain particles present that are exposed during the grinding process. Such a washing process may require 4 to 5 steps. The colored polyethylene particles are then dried, suitably dried with air. The resulting product is a dried, free flowing, dried particle having a particle size of about 5 to 8 microns.

It is observed that the grinding and washing process can wash approximately half of the original dye and in accordance with this factor should be taken into account. The jet milling of the matrix particles to a fine particle size exposes the dye surfaces and causes cracks in the polyethylene matrix. The particles have to be washed to remove any exposed dye. By applying a secondary coating of a suitable material, such as petrolatum, vegetable oil, coconut oil or a silicone fluid, on the encapsulated polyethylene particles, the need for washing can be eliminated. The coating acts as an effective surfactant sealer, covering any exposed surfaces and sealing any cracks in the surface of the particles. To apply the secondary coating it is preferable to disperse the ground particles by jet in liquefied petrolatum using a homogenizer or colloid mill. A paste with hydrophobic color with finely dispersed encapsulated lacquer particles is formed after cooling to room temperature. The particles can be used in any of the applications as described herein. However, it is observed that the particles produced in this manner do not have the uniform spherical shape of those particles that are produced with the spray freezing method. However, for certain applications where a small uniform shape is not necessary, such as veins in deodorants or soaps, those methods can produce an adequate product. With the spray freezing method the substrate-lacquer is recyclable. It is intended that the following examples illustrate the invention and not attempt to limit the scope thereof. In the examples, all parts and percentages are by weight unless otherwise specified.

EXAMPLE 1 Spray Coagulation Using specific lacquer FD &C Blue No. 1 and Polyethylene (PolywaxR 2000, Petrolite) and using conditions similar to those indicated above, the following process takes place: The polyethylene is first melted using Glas-cab Heating Mantle equipped with a temperature controlled automatic. When the polyethylene was completely melted, approximately 130-135 ° C, the aluminum lacquer was dispersed in the liquid polyethylene with the aid of a high shear homogenizer, such as the Silverson homogenizer. This dispersion takes approximately 15 minutes. The dispersion is then homogenized for an additional 30 minutes to ensure that the lacquer was uniformly dispersed in the polyethylene. The mixture was maintained at a temperature of approximately 125-135 ° C at all times. When a uniform dispersion was obtained, the mixture was then loaded into a suitable dispensing unit, which is optimized for the particular substrate selected. In this case, the temperature of the tank was approximately 137.7 ° C; the upper temperature of approximately 154.4 ° C; the pumping speed about 7 to 105; and the atomization pressure 4.78-5.27 kg / cm2.

The material was then collected and the production was recorded. The raw material was classified in the air to obtain the desirable or usable fraction (in this case approximately 5-15 μm). Using the previous experimental procedures, the coagulated spray dye colors manufactured were blue and red. The blue was obtained using aluminum lacquer FD &C Blue No 1 In an experiment the percentage of blue lacquer was 6% For a water color, a mixture of aluminum lacquer Blue No. 1 and aluminum lacquer D &C Yellow was used No. 10 The percentage of blue lacquer was 228% and 1 72% of yellow lacquer. In additional experiments using the same conditions, the percentage of blue lacquer No. 1 varied from 228 to 849%. Similarly, the matrix particles were obtained using dyes Yellow No 10 ranging from 1 24 to 291% Tank temperatures varied from 1377 to 1488 ° C, hose temperatures from 1488 to 1544 ° C, tempera Initially, from about 1544 to 1683 ° C, the pumping rates varied from approximately 75% to 30%, the atomization pressure varied from 1 05/1 40 to 492/534 kg / cm2 EXAMPLE 2 Spray Coagulation Process Using methods analogous to those previously indicated except for the substrate which is Polywax® 500 from Petrolite and lacquer was used FD &C Azu l N o. 1 to 12%. Alternatively, another example was executed using D &C Red Lacquer No. 10 to 18%. The two colors were kept separate in this experiment, although it was recognized that it is possible to add both the blue lacquer and the red lacquer together to the polyethylene at this stage and freeze the spray to obtain the desired color. The spray dryer used herein has a capacity of 2.5 kg / hr. [Generally, a lot size is about one Kg which is about 1 hour of operation time in the dryer]. Slowly the temperature of the polyethylene-dye mixture is this experiment is increased to about 125 ° C and maintained at that temperature with constant stirring until the spray dryer was ready to receive the material. The feed tank, feed line and nozzle of the spray dryer were preheated to 125-135 ° C, the polyethylene lacquer mixture was pumped into the hopper. The cooling air and the atomization air were activated and coagulation of the mixture was started. The atomization air pressure was between 2.46 kg / cm2 to 5.27 kg / cm2. The flow velocity of the polyethylene dye mixture, with a typical nozzle arrangement, (installation of sprinkler system # 4 fluid cover 60100, air cover 120), at 5.27 kg / cm2, resulted in the velocity measurement of Product flow 1.8 kg / hour. The pump speed was set at 30 ml / min (Cole-Parner peristack pump, MasterFlex, size 25, silicone tubing). As the polyethylene dye mixture was atomized by the spray nozzle, the spherical droplets formed inside the cooling chamber. The polyethylene-dye drops enter the cooling chamber at approximately 125 ° C. The droplets were cooled to the solidification point of about 86 ° C. The solidification takes place at a constant temperature that releases heat of crystallization. After the particles solidified, the cooling continues as the particles are discharged from the cooling chamber at about 40 ° C. The entire cooling-coagulation-cooling cycle occurs in a matter of seconds. In alternative experiments, using a trace line and nozzle, as well as a feeding vessel on a hot plate, Polyethylene (Polywax® 500) was used with a combination of lacquers with 3.6% Blue and 1.2% Yellow color; with a combination of lacquers with 3.6% Blue and 0.6% Yellow. Another polyethylene substrate, in this case a high density polyethylene grade (Acumist C, Allied Signal) was used with a combination of 3.6% Blue and 0.6% lacquers with yellow color. In addition to polyethylene, the Mekon White WaxTM (Microcrystalline Wax) was used with a combination of 3.6% Blue and 0.6% Yellow. Likewise, Carnauba natural wax with a combination of lacquers with 3.6% Blue and 0.6% Yellow color; a combination of lacquers with color 1 .8% Blue and 0.3% Yellow; and a combination of lacquers with color of 6.9% Blue and 0.6% Yellow were made successfully enough. Synthetic Carnauba Wax was also used as a substrate (Petronauba) with a combination of lacquers with 3.6% Blue and 0.6% Yellow color). As previously described, the lacquers were combined, to obtain the desired color, in the hot melt. In still another embodiment of the present invention, a combination of substrates was used with blue lacquers of% variation: polyethylene and Carnauba wax (equivalent amounts) with 3% blue lacquer; a 4: 1 ratio of polyethylene to Mekon White ™ Wax with 2% blue lacquer; a ratio of 9: 1 polyethylene to Mekon WhiteTM Wax with 3% blue lacquer; Mekon WhiteTM Wax alone with 3% Blue Lacquer; and polyethylene only with 1.0% lacquer.

EXAMPLE 3 Secondary Coating of Matrix Particles Using the above-prepared matrix particles of Example 1, a secondary coating of hydrogenated vegetable oil (Creamtex, Van den Berg) was applied. Batches made with this material showed some improvement over the discoloration or leachate than those particles made with the primary color alone.

In an alternative experiment, the coated matrix particles, approximately 15% w / w, were coated with 85% w / w of petrolatum. The matrix particles coated with Polywax "500 with 3.6% Blue / O.6% Yellow, the high density polyethylene (Acumist C Grade) as in Example 2 above, and three natural Carnauba wax substrates also made in Example 2 above An alternative experiment was also carried out where there was mineral oil and DOW silicone coatings in the polyethylene matrix particles: Example 3 (ii) 50 gms of Kaydol ™ mineral oil was mixed with 50 gms of the matrix particles in A laboratory beaker was mixed with a spatula for about 5 minutes to form a creamy mixture.The matrix particles were prepared according to the process herein and contained 800 gms of Polywax® 500, 17 gms of 12% blue lacquer, 5 gms of blue lacquer (40%) and 2 gms of yellow lacquer Example 3 (iii) Using 50 gms of Dimethicone (Dow Corning, 200 Fluid) and 50 gms of matrix particles as described in example 3 (ii) previous mixed Example 3 (iv) Using a combination of petrolatum or mineral oil, in a ratio of 1200 gm of petrolatum to 150 gm of white snow mineral oil were mixed and heated to 52 ° C, then 300 gms of matrix particles (as described in Example 3 (ii)) were exchanged and mixed with the secondary coating in a homogenizer from about 30 minutes and cooled to room temperature.

EXAMPLE 4 Dental Paste Process Using the procedure noted above in the specification, and in Example 3, a paste was made in a. Ross mixer and a Nauta mixer using the blue matrix particles (approximately 0.53%) and the yellow matrix particles (0.17% matrix particles) The paste was added to a general toothpaste formulation (for example, as can be found in U.S. Patent 4,340,583, issued July 20, 1982 to Wason, and U.S. Patent 5,094,843, issued March 10, 1992, to Mazzanobile et al.), a formulation is described below typical, first incorporating the matrix particle paste into the rubber component and then mixing as usual.% e P / P As will be recognized by one skilled in the art, abrasives suitable for use herein are calcium carbonate, dicalcium phosphate dihydride or silica; a source of fluoride ion for use herein is sodium monofluorophosphate or sodium fluoride; a suitable sweetener is sodium saccharin; a suitable detergent is sodium lauryl sulfate; and a suitable preservative is sodium benzoate. The above description fully explains the invention including the preferred embodiments thereof. Modifications and improvements of the modalities specifically described herein are within the scope of the following claims. Without further elaboration, it is considered that someone skilled in the art, using the above description, uses the present invention to its widest extent. Therefore the examples herein are considered as illustrative only and not as a limitation of the present invention in any way. The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows.

Claims (21)

1 . A process for forming a matrix pigment particle whose process comprises: a) heating a substrate to a molten liquid state; b) adding one or more lacquers with color or dyes to said molten liquid; c) maintaining the temperature of the substrate mixture. lacquer and freeze the spray of the mixture to produce a fine particle distribution of the matrix pigment particles upon cooling.

2. The process according to claim 1, wherein the color or dye lacquer is added to the substrate before heating to a molten liquid state.

3. The process according to claim 1, wherein the lacquer to substrate ratio is from about 0.5 to 9 percent.

4. The process according to claim 3, wherein the lacquer to substrate ratio is from about 1 to 6 percent.

5. The process according to claim 1, wherein the substrate: lacquer mixture is fed into a cooling chamber and atomization air is added.

6. The process according to claim 5, wherein the cooling chamber is fed into a cyclone by collecting the matrix pigment particles.

7. The process according to claim 6, wherein the matrix pigment particles are further collected in a filter bag.

8. The process according to claim 7, wherein the particles are classified in the air.

9. The process according to claim 1, wherein the matrix pigment particle is of a size between about 5 to 35 microns.

10. The process according to claim 9, wherein the pigment matrix particle is of a size between about 5 to 15 microns.

11. The process according to claim 1, wherein the substrate is polyethylene, microcrystalline wax or Carnauba wax.

12. The process according to claim 1, wherein the polyethylene is Polywax® 500, Polywax® 650, Polywax® 2000 or Polywax® 3000.

13. The process according to claim 1, wherein the colored lacquer is FD & C Blue No. 1, Yellow No. 10 or Red No. 10.

14. A particle of matrix pigment produced in accordance with claim 1.

15. The matrix pigment particle according to claim 14, which comprises a lacquer to substrate ratio from about 0.5 to 9 percent.

16. The matrix pigment particle according to claim 14, wherein the substrate is polyethylene, hard microcrystalline wax or Carnauba wax.

17. The matrix pigment particle according to claim 14, wherein the polyethylene is Polywax 500, Polywax® 650, Polywax® 2000 or Polywax® 3000.

18. The matrix pigment particle according to claim 14, wherein the colored lacquer is FD &C Blue No. 1, Yellow No. 10 or Red No. 10.

19. The matrix pigment particle according to claim 14, which is of a size between about 5 and 35 microns.

20. The matrix pigment particle according to claim 15, which is coated with a secondary coating.

21. The matrix pigment particle according to claim 20, wherein the secondary coating is petrolatum, mineral oil, vegetable oil, coconut oil or silicone fluid. SUMMARY The present invention is for a process for producing a matrix particle of a dye lacquer or dye whose matrix reduces the extraction or draining of the dye lacquer or dye in the surrounding medium. The process of the present invention is particularly useful in toothpaste formulations.