NZ201945A

NZ201945A - Dentifrices incorporating functional speckled material

Info

Publication number: NZ201945A
Application number: NZ201945A
Authority: NZ
Inventors: E J Gibbons; J P Hauschild; J R Principe; J B Barth; J Norfleet; J F Smith
Original assignee: Colgate Palmolive Co
Priority date: 1981-09-30
Filing date: 1982-09-16
Publication date: 1985-11-08
Also published as: KR880001982B1; IT8249161A0; CH655849A5; ES8504476A1; SE8703488D0; ES8407391A1; SE454945B; GB2106783A; DE3235000A1; DK29292D0; DK164842C; SE466382B; DK29292A; GB2144333A; CH657775A5; NL8203828A; SE8205521D0; PT75627B; ES528583A0; ES516053A0

Abstract

Functional agglomerated speckles, for incorporation in dentifrices, include agglomerates of a water insoluble powdered functional material and water insoluble, ethanol soluble ethyl cellulose, and may sometimes preferably also include a water soluble binder, such as polyvinyl pyrrolidone. Such speckles satisfactorily maintain their integrity and identity during processing of the dentifrice after addition of the speckles to a main dentifrice body but on storage, after packaging of the dentifrice in dispensing tubes, soften sufficiently so as to become essentially impalpable to one utilizing the dentifrice in brushing his teeth. Despite such softening the speckles continue to maintain their identity as speckles in the dentifrice. The speckles are especially useful in translucent or transparent gel dentifrices which contain components, such as flavouring and surface active agents, which may controllably soften the speckles on storage.

Description

<div class="application article clearfix" id="description"> 101945 Priority Date(s)*. | y -Cf-'S2 Complete Specification Filed. C„«: .M.IK.7M'- S'8'N6VY98^ Publication Date: Q"77 P.O. Journal, No: Patents Form No. 5 Number "^^^'ATENTS ACT 1953 Dated COMPLETE SPECIFICATION FUNCTIONAL AGGLOMERATED SPECKLES, DENTIFRICES CONTAINING THEM, AND PROCESSES AND APPARATUSES //We COLGATE-PALMOLIVE COMPANY a company incorporated under the laws of the State of Delaware, United States of America of 300 Park Avenue, New York 10022, United States of America do hereby declare the invention for which//we pray that a Patent may be granted to mk/us, and the method by which it is to be performed, to be particularly described in and by the following statement: - 1 - 201945 This invention relates to functional agglomerated speckles for incorporation in dentifrices. More particularly, it relates to such speckles and to dentifrices containing them, wherein the speckles are made from a water insoluble powdered functional material, such as a dental polishing agent, and water insoluble, ethanol soluble ethyl cellulose, 5 preferably with a water soluble binder, such as polyvinyl pyrrolidone. The invention also relates to processes and apparatuses for manufacturing such speckles and such dentifrices and to such dentifrices packaged in dispensing containers, such as transparent or translucent containers 10 through which the speckles in a transparent or translucent gel dentifrice may be viewed. To obtain desired visual effects the speckles will usually be of a color which contrasts with the rest of t*he dentifrice. ■s. Prior art toothpastes and gels which incorporated 15 contrastingly colored speckles are known. Although such speckles in some cases are primarily for aesthetic effects, they may be based on functional components, such as polishing agents. In the past various speckled dentifrices have included speckles which were initially palpable but became 20 impalpable during toothbrushing. Although such products have met with technical approval it has also been found desirable to market another type of speckled dentifrice, like that of this invention, in which the speckles, although readily visible and discrete, are impalpable initially, as well as 25 subsequently, during brushing of the teeth. Dentifrices containing visible and palpable, substantially water-insoluble, agglomerated particles of 2 019 4 5 polishing agents have been described in the prior art. Binding agents have been mentioned as employed in the manufacture of dental speckles and among the water soluble binders methyl cellulose and polyvinyl pyrrolidone (PVP) have been mentioned. However, methyl cellulose is water soluble and therefore does not provide a speckle which maintains integrity during lengthy processing. A dentifrice containing encapsulated sweetener has been described in the art, wherein ethyl cellulose was mentioned among various other materials useful for coating the sweetener to make the spheres. Water soluble and water insoluble binders for dental speckles have been disclosed together in the art but ethyl cellulose was not mentioned in such disclosure. Toothpaste formulations having dispersed therein visible agglomerated particles of dental polishing agent are known and advantages of both water soluble and water insoluble agglomerating or binding agents were recognized but ethyl cellulose was not suggested for use as a binder in such disclosures. Microencapsulation of sodium fluoride by lower alkyl cellulose, such as ethyl cellulose, and dispersing of the capsules in a dentifrice has been suggested but such suggestion was not relevant to agglomerating materials to produce dental speckles. The present invention is one wherein ethyl cellulose, which is water insoluble but ethanol soluble, is utilized as an agglomerating agent for a functional water insoluble powdered material made into dentifrice speckles of improved ^ (ft- ^ A ry, properties. Prior speckles, made with water soluble binders, such as methyl cellulose, could disintegrate during processing after mixing in with other dentifrice components, such as those in previously formulated gel or paste media, if the speckled 5 dentifrice was held too long in the processing equipment, which can happen, as when mechanical breakdowns of processing equipment occur. Such losses of integrity of the speckles could take place because such dentifrices contain water, which can solubilize the water soluble binders of the speckles and 10 lead to separation of the component particles of the speckles. The dissolving of the binder can be minimized in such cases by prompt processing but when filling line holdups cause processing times to be increased losses of product could result. Dentifrice speckles made with ordinary water insoluble binding 15 agents, as disclosed in the art (such art does not disclose ethyl cellulose), when dispersed in dentifrice gels or pastes tend to be palpable, and although that may often be desirable, in some dentifrices, e.g., those intended for use by persons with sensitive gingiva, it is not. 20 The ethyl cellulose employed as a binder for functional speckles in accordance with the present invention satisfactorily maintains the integrity of the speckles in aqueous dentifrice media for a sufficiently long time to allow processing after incorporation of the speckles in the denti-25 frice. Yet, apparently because of the presence of components of the dentifrice which tend to soften the speckles on storage, such as flavoring agents, and in some cases, surface active - 4 _ 201945 agents, the speckles in the dentifrice are softened sufficiently during storage so that, although they maintain their integrity and independence and their distinctly separate appearances until the product is used, they are impalpable and are readily 5 disintegrated during toothbrushing. In some preferred formulations, such as those which may contain lesser proportions of flavoring agents (and dental detergent and any other solvents or lipophiles) or in those dentifrices includingmaterials of lower solubilizing (for 10 ethyl Cellulose) properties, the presence of an auxiliary binder which is water soluble, e.g., PVP, can produce the desired impalpability. Still the speckles' integrity will be maintained due to the presence of the ethyl cellulose. Once made, preferably by a process which comprises 15 "moistening" a water insoluble functional material in powdered form (or a mixture of such functional powder and water soluble binder) with a solution of water insoluble ethyl cellulose in a volatile solvent, compacting, converting to particulate form and drying, the speckles may be controllably directed 20 onto a stream of dentifrice and adhered thereto to distribute them evenly, and preferably certain apparatuses will be used. In accordance with the present invention functional agglomerated speckles, for incorporation in dentifrices, comprise agglomerates of a water insoluble powdered functional 25 material and water insoluble, ethanol soluble ethyl cellulose, sometimes preferably with a water soluble binder also being present. - 5 - '0194 The functional agglomerated speckles are comprised of two essential components, a water insoluble powdered functional material and a water insoluble, ethanol soluble ethyl cellulose. The first may be characterized as the functional bodying agent and the second as the binder. Various functional materials, all of which are preferably water insoluble, or at least, slowly soluble, can be employed, including colorants, such as pigments, germicides, ion exchange agents, polymeric materials (which may contain other active components, sometimes water soluble materials), and flavorings, but it is highly preferred that the functional base material for the speckles be a polishing agent or include a major proportion thereof. Of the polishing agents, normally utilized in dry powder form to make the agglomerated speckles, those preferred are dicalcium phosphate, tricalcium phosphate, insoluble sodium metaphosphate, alumina, silica, magnesium carbonate, calcium carbonate, calcium pyrophosphate, bentonite and zirconium silicate, and suitable mixtures thereof. Both anhydrous or calcine?! forms of these materials, such as calcined alumina, and hydrated forms, such as dicalcium phosphate dihydrate, may be employed but the anhydrous or calcined materials are often preferred. Because the agglomerates will normally desirably be opaque there is no need to match refractive indices with those of the dentifrice vehicles (including other components, too) but "transparent" polishing agents, with such a matching refractive index, e.g., 1.44 to 1.47, may be used to make transparent or translucent speckles, as v/ell as being used in making a clear gel dentifrice body containing polishing agent. Such "transparent" polishing 7-01945 agents include colloidal silicas and those sold under the trademark Syloid, as Syloids 63, 65, 72 and 74, under the mark Santocel, as Santocel 100, and as Zeo's 49, 113 and 119, and Zeodent. Also, synthetic alkali metal aluminosilicate complexes may 5 be particularly useful, because they have refractive indices close to those of duntal vehicles including water, glycerol, sorbitol and gelling agent, which are those normally employed in the manufacture of dentifrices. The water insoluble, powdered functional material 10 utilized to make the present speckles will normally be of initial particle sizes in the range of 0.5 to 20 microns, preferably being within the range of 1 to 10 microns, and more preferably of 2 to 8 microns. However, in some instances ■j larger particle sizes may be employed, as when the agglomerat-15 ing operation tends to size-reduce some of the powder, as may happen in mixing before actual agglomeration begins. The binding agent for the present speckles is ethyl cellulose. This effective binder is water insoluble but is soluble in ethanol, and is gradually soluble in an 20 aqueous glycerol-sorbitol medium which also contains "solvents" for it, such as flavoringsand surfactants, which are usually present in the dentifrices of this invention. Such ethyl cellulose will usually have an ethoxy content in the range of about 45 to 50%, preferably 48 to 50% or 48 to 49.5%. 25 In a preferred ethyl cellulose, such as that marketed by The Dow Chemical Company under the trade name Ethocel Standard 10 Premium Ethyl Cellulose, the ethoxyl content is in the range of 48.0 to 49.5%; the viscosity is 9 to 11 centipoises; the moisture content is 2% maximum; chloride, as NaCl is 0.15% maximum; and ash content is 0.15% maximum. - 7 - 7.n 1945 Ethyl cellulose resins suitable for use as binders for the present speckles are available commercially as white to light tan granular powders of a degree of etherification such that there are 2.25 to 2.58 ethoxy groups per anhydro-5 glucose unit, which corresponds to 45.0 to 49.5% ethoxy content (by weight). Of two such grades of ethyl cellulose the materials which are preferred for the practice of the present invention have ethoxy contents in the range of 48.0 to 49.5% (by weight), and less preferred materials are of 10 ethoxy contents in the 45.0 to 46.5% range. Of course, such products are available in different viscosity ranges, usually from 3 to 110 centipoises, with the less preferred material tending to be more viscous. -s. _ The preferred or "standard" grade of ethyl cellulose 15 tends to be soluble in aromatic hydrocarbons, hydroaromatic hydrocarbons, chlorinated aliphatic hydrocarbons and naval stores. It is also soluble in monohydric aliphatic alcohols, such as ethanol; monohydric cyclic alcohols, such as benzyl alcohol phenylethyl alcohol and pine oil; ether alcohols, such 20 as glycol ethers; ethers, such as diethyl cellosolve; esters, especially acetates, such as isopropyl acetate and sec-amyl acetate and esters of hydroxy acids, such as methyl salicylate; and ketones, such as cyclohexanone and acetophenone. Generally, the less preferred or "medium" ethoxy grade of ethyl 25 cellulose is less soluble than the standared grade and so may be more suited for use when greater proportions of solubilizing materials are present in the dentifrice formula. - 8 - 201945 The water soluble binders which are useful for making the combination binder sometimes preferably utilized for production of the speckles of this invention include, among others, gum acacia; gelatin; starches, both natural and modified; alkali 5 : metal carboxymethyl celluloses, particularly sodium carboxy-methyl cellulose; polyethylene glycols; sugars, such as glucose and sucrose; methyl cellulose; carboxyethyl hydroxy-ethyl celluloses; alginates, particularly sodium alginate; polyvinyl alcohol; carrageenan, preferably Irish moss; 10 xanthan gums; gum tragacanthj and PVP. It has been found the PVP is stable in the presence of ethyl cellulose, does not bleed excessively from the speckles in which it is incorporated as a bindej: in combination with ethyl cellulose, and lends itself to use to adjust the binding properties of 15 the combination binder, so as to make such binder readily adaptable for employment in the same desired total proportion in a variety of dentifrice formulations, wherein the proportion of ethyl cellulose to PVP may be adjusted accordingly. Also important is the characteristic of the combination 20 binder in the invented speckles of being sufficiently hard and firm so that during processing the speckles do not dissolve excessively and yet are sufficiently softenable on storage in the dentifrice in which they are incorporated so that they become impalpable by the time the dentifrice is 25 used. They do not soften excessively so as to cause streaking - 9 - 201945 in the tube or during discharge,, but by adjustment of the proportion of ethyl cellulose to PVP, increasing the PVP, controlled streaking, if desirable, may sometimes be obtained. PVP will usually be of molecular weights in the 5 30,000 to 50,000 range and the PVP preferably employed in the present invention is of a molecular weight of about 40,000. Such a product, which is marketed by GAF Corporation under the trademark Plasdone, as Plasdone K 29-32 and K 26-28, has average molecular weights designated by indicated k 10 values, with K-30 being equivalent to about 40,000. PVP is available as a light colored powder containing less than 5% moisture, 12.6 ±0.4% of nitrogen, less than 2 parts per million of arsenic and less than 20 p.p.m. of heavy metals. It is soluble in cold water and in a variety of organic 15 alcohols, acids, ether-alcohols, ketone-alcohols, chlorinated hydrocarbons, esters and ketones, but is insoluble in hydrocarbons and some ethers, chlorinated hydrocarbons, ketones and esters. It is compatible with various natural and synthetic resins, inorganic salts and with many synthetic 20 organic detergents, including those commonly employed as dental detergents, e.g., sodium higher fatty alcohol sulfate and poly-lower alkoxylated alcohol sulfates. Although it might have been expected that the best speckles would be made from the least soluble binder material, 25 it has been found that ethyl cellulose, as described in this invention, makes speckles of ideal properties, which maintain 7 019 45 their individuality and integrity while being processed and during storage, but which are also essentially impalpable during use of the dentifrice in brushing. If desired, the character of the speckles may be changed, as by modifying 5 the degree of ethoxy content of the ethyl cellulose and/or by blending with it other substantially water insoluble binders of known types. Similary, as when the content of lipophilic materials in the dentifrice (less speckles) is less, so that the speckles are less likely to 10 become impalpable on storage, water soluble binder, e.g., PVP, may be used with the ethyl cellulose to increase the softening of the speckles. Such regulation of speckle properties may also be effected by using more water soluble binder(s) or more of such binder(s) or by changing the molecular 15 weight thereof (as by lowering the molecular weight of PVP). The properties of the speckles may also be regulated by adjusting the proportions of functional material and the binder, as will be referred to subsequently. Thus, agglomerates may be made which will be stable during processing after mixing, such 20 as deaerating and filling, yet which will break up rapidly after the dental cream is extruded from its container or, if desired, such breaking up may be retarded so that the agglomerates will feel harder and somewhat firmer to the user during brushing of his teeth.. It is normally highly preferable for 25 the speckles to be essentially impalpable on use, while still maintaining their identity in the dentifrice. - 11 - The binder will normally be of particle size like that of the functional powdered material of the speckles, especially if the agglomerates are to be made, at least in part, by compacting of powdered materials. Because normally 5 the speckles will be made by utilizing an alcoholic solution of the ethyl cellulose, the particle sizes thereof may be of relatively little importance. However, when water soluble binder is present it is considered that its sizes are preferably like those of the functional material. 10 The speckles, while sometimes white or colorless and possibly even translucent or transparent, or approaching such appearances, may also be colored, normally due to containing a suitable proportion of dye or pigment or a mixture of dyes and/or pigments. Any non-toxic dye or pigment of a 15 suitable color, usually a strong color, such as one of a suitable hue, with a Munsell chroma greater than 4 and a Munsell value in the 4 to 7 range, may be utilized, and in some instances weak colors or pastels may be satisfactory or desirable. It is usually best to employ a dye or pigment 20 which is approved for drug and cosmetic use (D&C) or for food, drug and cosmetic use (FD&C). Representative of suitable dyes are D&C Reds No's. 2, 3, 6, 7, 8, 9, 10, 11, 12, 13, 19, 30, 31, 36 and 37; D&C Blue No. 1; FD&C Blues No's. 1 and 2; FD&C Reds No's. 1, 2 and 3; FD&C Yellow No. 5; 25 cosmetic grean oxide; and cosmetic red oxide. Pigments of the foregoing dyes, known as lakes, are also suitable for yse in coloring the speckles but normally the dyes will be preferred. The mentioned pigments are often composed of dyes supported on a finely powdered insoluble carrier and the pigments are - 12 - 201945 dispersed rather than dissolved in the medium to be colored. The particle sizes of pigments employed may be within the range previously given for the polishing agents or may be sized like the binder. Sizes may be finer, e.g., in the 0.01 to 1 5 micron range. Particle sizes of dyes may be similar but because they are normally employed in dissolved state, in water or solvent, preferably being oil soluble and being dissolved in the appropriate solvent, sizes are not important as long as the powder or particles are small enough so as to make 10 the dye readily soluble in the solvent chosen. The speckles .of this invention may be made by any suitable method, either wet or dry processes. When ethyl cellulose is the sole binder and a wet granulation process is employed the ethyl cellulose, in dry powder form, is 15 first preferably blended with polishing agent and dye or pigment, if present, and ethanol. Water and/or lipophilic solvent may be present with the ethanol and a dye or pigment for coloring the speckles may also be present. Alternatively, and often preferably, an ethanol solution of 20 ethyl cellulose may have a suitable dye or pigment and the polishing agent admixed with it. The proportions of components will' be such as to result in speckles of the desired composition and the proportion of solvent(s) will normally be from 5 to 50% of the mix, preferably 5 to 25% thereof. The production 25 of the dispersion may be by means of a Hpbart mixef, Dravo pan, or other suitable mixing device or granul.ator for wetting powder(s), and the order of addition of the various components of the dispersion may be adjusted as best befits - 13 - 2 019 4 5 the mixing or blending apparatus.employed. A preferred way of producing the speckles is by forcing the "wetted" mix of polishing agent and ethyl cellulose (with dye or pigment, if used) through a screen having uniform openings, which usually will be in the range of about 150 to 2,000 microns (about in the No. 10 to 100 sieve tange, U.S. Sieve Series) and the "extruded" agglomerates are then dried, usually either in air or in an oven. Instead of screens other means, such as pressure extruders, may be employed for extruding or otherwise pelletiz-ing the mix, after which the particles resulting are dried. The particles are then classified into desired size ranges, normally in the No's. 10 to 80 range, preferably No's. 40 to 80 and more preferably No's. 30 to 60 (U.S. Sieve Series). s, Of course, if the wet mass is formed in a Dravo pan the forced screening or other extruding may be omitted. Generally, when the particle sizes are larger than 2,000 microns (No. 10 sieve) .they will be less satisfactory for introduction into the oral cavity of a user and when less than about 177 microns in diameter (No. 80 sieve) they will not be as readily apparent and hence, will not be of as attractive an appearance. Instead of employing the wet granulation process a dry or slugging process may be utilized, wherein the components of the speckles may be pressed to large tablet size and such tablet may then be broken up, with particles thereof in the desired size range being separated from the others. In such tableting process it may be desirable to employ a water - 14 - 2 019 45 insoluble- lubricant, such as talc, magnesium stearate, calcium stearate or stearic acid, which also helps to facilitate agglomeration. Similarly, such materials and other water insoluble adjuvants may be present when wet 5 granulation methods are used. The speckles made are preferably dry, containing no moisture, but moisture contents of up to 10%, e.g., 1 to 5%, may be present without causing any serious adverse effects on the properties of the speckles. The proportions in the speckles of water insoluble 10 powdered functional material, such as dental polishing agent, and binder, such as ethyl cellulose or ethyl cellulose plus water soluble binder, will be such that the binder will be the minor component of the speckles and the powdered functional '*N» , material will be the major component thereof (although allow-15 ance should be made for the presence of other materials too, such as colors and adjuvants). Generally, the dental polishing a i ; '■ agent or functional material is from 75 or 80 to 98% of the speckles, preferably 85 to 97% thereof, the binder or combination of binders will be 2 to 20% of the speckles, preferably 20 3 to 15% thereof and the colorant will be 0 to 5% of the speckles, such as about 0.05 to 1% thereof, all on a dry -basis, free of water and ethanol or other solvent. When the combination of binders is present the proportion of ethyl cellulose to water soluble binder (PVP) is in the range of 25 1:10 to 10:1, preferably 1:5 to 5:1, more preferably 1:2 to 2:1, and most preferably 1:2 to 1:1, e.g., 2:3. - 15 - 1 A . The dentifrice in which the speckles are distributed may be any suitable such product, because in the present invention it acts primarily as the medium for the speckles, maintaining them independent, individual and separate, 5 while performing its normal dentifrice functions. Opaque dentifrices are useful media for the present speckles but it is highly preferred that the dentifrice be transparent or translucent and normally be of a type characterized as a gel. Dentifrices normally comprise water, humectant, gelling 10 agent, dental detergent and a dental polishing agent, usually with flavoring and/or coloring too. Among various functional adjuvants are fluorides, stabilizers, anti-caries agents and antibacterial compounds^ The water employed will preferably be deionized 15 water, although city waters, both soft and hard, may also be utilized. The gelling agent is normally a water soluble natural or synthetic gum or gum-like material, among which are carrageenan, gum tragacanth, xanthan gum, alginates, alkali metal carboxymethyl cellulose (preferably sodium 20 carboxymethyl cellulose), hydroxymethyl carboxyethyl cellulose, polyvinyl pyrrolidone, starch, and hydrophilic colloidal carbdxyvinyl polymers, such as those sold under the trademarks Carbopol 934 and 940. Although various polyols may be utilized as humectants those preferred are of 3 to 6 carbon 25 atoms and 3 to 6 hydroxyls per molecule, and those of choice are glycerol and sorbitol. The glycerol is in normal liquid state> generally being about 99% or more pure, and sorbitol, normally being a solid, is frequently utilized as a 70% - 16 - 2 019 45 aqueous SQlution thereof (70% sorbitol, 30% water). The three mentioned components may be considered as the main constituents of the dentifrice vehicle, in which flavor and detergent may also be incorporated. Such detergent may 5 include a soap but normally will be a non-soap synthetic organic surface active agent having detersive properties. Preferably such detergent will be of the anionic type, although nonionic detergents are also useful, ampholytic detergents can be employed, and cationic detergents can be 10 acceptable under some circumstances. The preferred anionic detergents are especially useful because they combine excellent cleaning action and foaming properties. Normally, such compounds include hydro-philically and lipophilically balanced moieties, with the 15 lipophilic moiety usually being a higher fatty alkyl or acyl of 10 to 18 carbon atoms, preferably 12 to 16 carbon atoms, and the hydrophile being alkali metal, e.g., sodium,potassium, or ammonium or lower alkanolammonium. Suitable such anionic detergents are: the water soluble salts (normally 20 alkali metal and preferably sodium or potassium) of higher fatty acid monoglyceride sulfates, such as the sodium salt of the monosulfated monoglyceride of hydrogenated coconut . oil fatty acids? higher alkyl sulfates, such as sodium lauryl sulfate; alkylaryl sulfonates, such as sodium linear 25 dodecyl benzene sulfonate; higher alkyl sulfoacetates; higher fatty acid ester 1,2-dihydroxypropane sulfonates; the sodium salts of sulfated polyethoxylated alcohols; and the substantially saturated higher aliphatic acylamides of lower - 17 - 201945 aliphatic aminocarboxylic acid ctpmpounds, such as N-lauroyl sarcosine, and the sodium, potassium and ethanolamine salts of N-lauroyl-, N-myristoyl-, and N-palmitoyl sarcosine, all of which sarcosine compounds are preferably substantially free from soap or similar higher fatty acid material. Among the nonionic detergents, ethoxylated sorbitan mono-stearate, with approximately 20 mols of ethylene oxide per mol; condensates of ethylene oxide with propylene oxide and propylene glycol (Pluronics); polyethoxylated higher fatty alcohols, such as the Neodols (23-6.5 and 45-11, for example); and condensation products of alpha-olefin oxides containing 10 to 20 carbon atoms, polyhydric alcohols containing 2 to 10 carbon atoms and 2 to 6 hydroxyl groups, and either '■N., ethylene oxide or heteric mixtures of ethylene oxide and propylene oxide, are useful. Quaternized imidazoyl derivatives, such as Miranol C2M, and other Miranols represent useful amphoteric detergents and the quaternary ammonium' halides, such as dimethyldicetyl ammonium bromide, represent cationic detergents. The various polishing agents, which are dispersed in the dentifrice vehicle (or vehicle plus detergent and any other, adjuvants) are those previously described for conversion to speckle form. Also useful in such group of materials are synthetic finely divided silicas, such as those 3old under the trademarks Cab-O-Sil M-5, Syloid 244, Syloid 266, Aerosil D-200, Zeosyl 200 and Zeothix 265, which are normally utilized for only a small percentage of the polishing agent, normally being no more than 1 to 9% by weight of the total dentifrice, - 18 - 201945 and which are useful for thickening or gelling the vehicle and improving the clarity of the dentifrice. The dentifrices of this invention will normally contain suitable flavoring and/or sweetening materials, Examples of flavors include the flavoring oils, such as those of spearmint, peppermint, wintergreen, sassafras, clove, sage, eucalyptus, cinnamon, lemon and orange, and the sweetening agents include sucrose, lactose, maltose and saccharin. Desirably for fluoride dentifrices there will also be present sodium fluoride, stannous fluoride, potassium fluoride, potassium stannous fluoride, sodium hexafluoro-stannate, stannous chlorofluoride and/or sodium monofluoro-phosphate. v. The flavoring materials include various well known essential oils, mainly terpenes; esters; alcohols, aldehydes, ketones,and other aromatic substances, many of which emit aromatic odors and fragrances. Because flavor is a simultaneous physiological and psychological response obtained from the presence of a substance in the mouth and depends on the senses of taste, smell and feel, with smell often being of primary importance, it is not surprising that aromatic materials are important components of flavors. In the present instances advantage is taken of this fact and of the chemical natures of such materials which, as was previously indicated in the discussion of solubilities of ethyl cellulose, permit the ethyl cellulose binder in the present speckles to be slowly solubilized by the solubilizing substances in the flavoring material, causing softening of the speckles but not causing their disintegration. For example,the - 19 - 201945 terpenes, which are hydrocarbons and which constitute an important class of perfumery or flavor materials, are good solvents for the ethyl cellulose of this invention, as are many other flavoring materials, such as those previously named (as flavoring oils) above, and others well known to the perfumery and flavoring arts. By utilizing the flavoring essences in the dentifrice composition to soften the ethyl cellulose speckles and thereby make them impalpable, which is an aim of this invention, it is unnecessary to add another component to the dentifrice or the speckles for this purpose. Also, because of the relatively small proportion of flavoring material normally present in a dentifrice, with the proportion of the lipophilic part of the flavor often being lower, a desirable slow softening of the speckle particles can result, usually due to a relatively low mass transfer rate for the "solvent" material, which transfer rate is especially slowed due to the gelatinous nature of the dentifrice. Thus, even if some flavoring material at the interface with the speckle started to soften the ethyl cellulose thereof while the dentifrice was being blended,the flavor solution of ethyl cellulose would soon become saturated and this would inhibit further quick dissolving of the ethyl cellulose. Still with the passage of the normal time a dentifrice spends in storage before sale and use, which time will often be at least about 2 weeks and sometimes more (with certain dentifrice formulas it is desirable to allow them to age to improve flavor and product uniformity), the speckles become impalpable, yet remain distinct. - 20 - ?01945 In the preceding discussion references were made to the ethyl cellulose binder but it is recognized, that sometimes a water soluble binder, such as PVP, will also be present and the references were also meant to., apply to such speckles and 5 speckled dentifrices. In such products the ethyl cellulose holds the speckle together until it is "solubilized" by the lipophiles in the dentifrice, and the PVP allows less ethyl cellulose to be used and facilitates the desired softening of speckles in dentifrices containing lesser 10 proportions of solubilizing flavoring and other lipophiles. Although it is considered that the flavoring materials, particularly the lipophiles, which exert substantial solvent action on ethyl cellulose, are the most important slowly solubi-lizing components of the present dentifrice, the surface active 15 agent component, which includes a lipophilic moiety, may also have an appreciable solubilizing effect and by means of its wetting action, may promote mass transfer in a dentifrice tube and thereby increase the solubility rate of the ethyl cellulose. It is also possible that combinations of other constituents of 20 the dentifrice, including some of the sweetening agents and vehicle components, will further assist in solubilization of the ethyl cellulose to the extent desired, while not promoting premature softening of the speckles. Colorants, such as those previously mentioned with 25 respect to the speckles, may be employed,, normally in lesser proportion, so as to provide a base which contrasts with the speckles. Various other adjuvant materials may be present in the dentifrice, including preservatives, silicones, - 21 - ^ Q 1 94 chlorophyll compounds and ammoniated materials. Normally, when a gel dentifrice is made which is intended to be transparent or translucent, the polishing agent chosen will be one having an index of refraction closely matching that of 5 the rest of the dentifrice medium. Of course, in such clear gel formulations the amount present of insoluble materials which would cloud the gel will normally be minimized. When the pH of the dentifrice is adjusted, and the pH is desirably within the range of 3 to 10, more desirably from 10 3.5 to 5 when stannous ions are present and 4.5 to 7 in the absence of such ions, organic acids, such as citric., malonic, and fumaric acids, may be employed. In the dentifrice of this invention a dental polish- N ing agent is uniformly distributed throughout the vehicle of 15 water, humectant and gelling agent, with a dental detergent and the desired proportion of flavor already in it. Then the speckles, which also preferably contain a polishing agent (and often of a different type from that in the body of the dentifrice), are uniformly distributed throughout the dentifrice, 20 usually comprising 0.1 to 10% of the dentifrice, preferably 0.5 to 5% thereof, jnore preferably 1 to 3% thereof and most preferably 1.5 to 2.5% thereof. The dental base will usually comprise: about 5 to 30% water, preferably 10 to 25% and more preferably 10 to 20%; about 20 to 70% of humectant, preferably 25 polyol humectant, more preferably 45 to 65% thereof- and most preferably 50 to 60% thereof; and about 0.1 to 5% of gelling agent, preferably 0.1 to 1% and more preferably 0.2 to 0.5% thereof. The humectant is preferably a mixture of glycerol and - 22 - sorbitol wherein the glycerol content is 5 to 40% of the dental base, preferably 20 to 30%, and the sorbitol content is 5 to 50%, preferably 25 to 35%. The preferred gelling agent is sodium carboxymethyl cellulose, and a preferred proportion thereof 5 utilized is about 0.3 to 0.4%. The dental detergent content will normally be from 0.5 to 5%, preferably 0.5 to 3%, and a preferred such detergent is sodium lauryl sulfate. The polishing agent in the dentifrice base, exclusive of that in the speckles, is normally 10 to 40%, preferably 15 to 30% 10 and most preferably 20 to 25%, including Syloid 244 type silicas, which are also employed for thickening. Various other materials, including flavors (usually 0.5 to 2 i,) , color, preservatives, sweetener^,and tooth hardeners (fluorides) will normally total no more than 10% of the dentifrice, 15 preferably being from 2 to 7% thereof. Utilizing the proportions of the various constituents within the ranges given, with respect to the speckles and the medium in which they are distributed, results in an attractive product which is stable during storage and in which the speckles are uniformly 20 and attractively distributed. To prepare the speckled dentifrice, after first producing the speckles, is comparatively simple but an important consideration is that minimal mechanical agitation should be employed so as to prevent or delay any disintegra-25 tion, softening and solubilization of the speckles in the dentifrice. It is considered that lipophilic materials and solvents present, such as those in flavoring oils, will - 23 - 2 019 4 5 slowly solubilize ethyl cellulose, but not to an objectionable extent in the absence of vigorous agitation in processing. If the dentifrice is at an elevated temperature during such mixing, possibly due to manufacturing limitations in process-5 ing,it is even more important to minimize agitation. However, when the ethyl cellulose binder or combination binder is used in the manufacture of the speckles, manufacturing restrictions may be less stringent, but care should still be exercised. Suitable equipment for distributing the speckles throughout 10 the dentifrice may include conventional Banbury or dough mixers operated at low speeds but other gently operated blenders may also be used providing that mixing is controlled so as to prevent substantial breakdowns, dissolvings or disintegrations of the speckles. When such mixers are used mixing blade speed 15 will normally be on the order of one to five revolutions per minute (r.p.m.) and mixing will last from one to five minutes. After completion of the blending the dentifrice is deaerated and filled into containers, such as transparent resilient or collapsible tubes. If vacuum is employed during mixing 20 operations deaeration may be omitted. Although the manufacturing apparatus and process above are standard for making speckled dentifrices, it is much preferred to employ methods that have recently been invented for facilitating blending of the speckles into the dental gel 25 body without excessive agitation. Such processes and apparatuses, and other aspects of the present invention have been set forth in the following description and the rest of this specification, and the invention will be readily understood from these, taken - 24 - in conjunction with the drawing," in which: FIG. 1 is a perspective view of a tube of dental gel of this invention, including a removed cap, and a toothbrush; FIG. 2 is a schematic representation of an apparatus of this invention for making a speckled dentifrice from a dental composition and previously produced speckles; FIG. 3 is an enlarged perspective view of a portion of the "speckling apparatus" of this invention, illustrating application of speckles to a gel stream or ribbon; FIG. 4 is a schematic representation of another apparatus of this invention for making a speckled dentifrice; and FIG. 5 is an enlarged perspective view of a portion of the "speckling apparatus" of FIG. 4, illustrating application of the speckles to gel streams or ribbons. In FIG. 1 there is shown a clear walled container 11, which is made of transparent polymeric material (PVC), including body 13, shoulder 15, threaded neck 17 and cap 19, with the cap having been removed from the tube. Although it is preferred to make the packaged dentifrice by utilizing a deformable tube of clear or translucent synthetic organic polymeric material, such as polyvinyl chloride, polyethylene, poly-vinylidine chloride or similar material through which the attractive appearing speckled dentifrice may be viewed, collapsible opaque tubes, such as those of aluminum or other metal, may also be used. As illustrated, some of the - 25 - ^ ^ A % dentifrice 21 is being dispensed' from tube 11 through neck 17 onto the bristles of a toothbrush 12. In the dentifrice there are clearly shown invented speckles 23 in the continuous dentifrice medium 25. It is noted that such speckles are initially 5 impalpable although they are easily visible. During tooth-brushing they break down into smaller entities of essentially the same sizes as the component polishing agent. Of course, the speckle polishing agent acts together with that in the dental gel to help clean and polish the teeth. 10 In FIG. 2 there are shown gel-making vessel 111, which often preferably will be a Hobart or Dopp mixer, in which the various components of the dental composition, including vehicle, gelling agent, polishing agent, flavor, color, detergent, preservative and any other adjuvants, are mixed 15 together, sometimes under vacuum, to form a composition to which speckles, preferably functional speckles, such as those based on a dental polishing agent, are to be added, to make a speckled dentifrice. Variable speed motor and/or drive 113 powers a positive displacement pump 115, at a controllable speed, to 20 deliver the gel to an outlet 117, preferably a somewhat restricted flat orifice, through which it is extruded or discharged as a flat ribbon or other suitable stream 119 onto which speckles 121, in discrete bit or particulate form, are deposited. Pump 115 may be set to control the gel feed rate and by also controlling 25 the feed rate of the speckles the desired proportion of speckles may be continuously added to the flowing gel. Preferably pump 115 will be one which subjects the gel to little or no shearing action, so as to maintain its consistency - 26 - 2019 45 (viscosity), and screw pumps with walls of elastomer are preferred, such as those of the Moyno type. Gel feeding outlet means or extruder 117 is preferably enclosed in a walled vessel or container 123 and usually will be so position-5 ed therein that ribbons of gel containing speckles on the surface thereof, produced in such vessel, will fall vertically to the bottom thereof near the center of the vessel, from which they may be removed through central outlet 125. The speckles to be added to the dental gel in 10 prescribed proportion are contained in a hopper 127 for a controllable flow rate feeder 129, preferably of a helix type, including speed control 131, which feeder discharges the speckles at a desired controlled rate through an outlet 133 onto a funnel shaped directing means 135, which shapes 15 the discharge stream of speckles as desired so that as they leave it they form a falling stream or curtain which matches the ribbon of gel flowing from outlet 117 preferably being such that the speckles fall substantially vertically to deposit on and become adhered to the inner 20 portion of the gel ribbon, with none missing contact with the gel. Preferably the speckle curtain covers a substantial part,, e.g., 40 to 95%, preferably 60 to 90% of the width of the gel ribbon, and the curtain should not be so wide as to result in any substantial proportion of speckles missing the ribbon. 25 However, it will be desirable to have the purtain be'of a width only slightly less than the ribbon when feasible, e.g., 80 to 90%. Lines 137, 139 and 141 connect to. vacuum sources 143 and 145, respectively but while the use of vacuum is - 27 - ' 019 45 desirable to prevent air bubbles.from entering the dentifrice, with careful processing the infiltration of such bubbles may be avoided without the use of vacuum. After the speckled dentifrice is dropped through outlet 125, a pump 147, which is preferably a screw pump, such as one of the Moyno type, powered by variable speed motor 149, pumps the product in a gentle manner to static mixer 151, preferably of the Kenics type, where it is gently blended without disintegration or solubilization of the speckles therein, and is uniformly mixed. It then passes through line 153 to a receiver 155, which may be feed tank for a tube filling machine, not illustrated. In FIG. 3 gel feeding means 157 includes a delivery tube 159 and a nozzle portion 117, with such nozzle including a flat rectangularly shaped opening 161. The gel feeding means and the opening in the discharge "nozzle" portion thereof may be adjustable. Thus, the feed direction could be changed as desired, and the angle of discharge could be varied but the feed direction should have a horizontal component and is usually from 0 to 45°, e.g., 10 to 30°, from the horizontal. Also, the rectangular orifice can be changed in size, so as to be more restricted, but care should be exercised to keep the gel ribbon coherent so the ribbon will not be thin beyond the gel strength. Usually it will be from 1 mm. to 1 cm. thick, e.g., 2 to 6 mm. The stream or ribbon of gel is directed so that the stream or curtain of speckles may fall on it correctly, preferably when the speckles are falling substantially vertically and the gel is moving in a direction with a horizontal component, go - 28 - 019 4 5 that the gel passes under the failing speckles, which contact it and adhere to it. The gel ribbon 163 is shown falling downwardly and to the right, while speckles 165 fall on to it from a discharge spout 167 of directing means 5 135 (FIG. 2). In FIG. 4 there are shown gel-making vessel 211, which may be like that of FIG. 2 and functions similarly. Valves 213 and 215 in line 217, together with controllable speed positive displacement pump 219, allow recycling of 10 the gel through the mixer, if desired. Lines 220 and 221, and valves 222 and 223 permit discharge of the dental gel (or paste) for cleaning or production of a dentifrice not containing any speckles-* Line 225 and valve 227, when opened, with valves 215, 222 and 223 closed and with valve 213 15 open, gel pump 219 operative and mixing means 211 containing dental gel, allow delivery of the gel at a controlled rate to gel feeding means 229 and through line 231 to a similar but opposing gel feeding me^ns 233, both of which means include relatively restricted and flattened orifices 20 or nozzles, as better illustrated in FIG. 5. They also desirably include additional supporting means for the gel as it leaves the nozzles to help it maintain its ribbon shapes and to guide its flows. Pump 219 may be set to control the gel feed rate so that by controlling the feed rate of 25 the speckles the desired proportion of speckles may be continuously added to the flowing gel. Preferably, pump 219 - 29 - 20194 will be like pump 115, previously described. Gel feeding means or extruders 229 and 233 and line 231 are preferably enclosed in a walled vessel or container 23b and usually will be centrally positioned therein so that sandwiches of gel with speckles 5 in the interior thereof, produced in such vessel, will fall vertically or substantially vertically to the bottom thereof near the center of the vessel, from which they may be removed through an outlet communicating with line 237. The outlet (unnumbered) is at the base of the vessel and it is 10 preferable that the gel feeding means 233 terminate near the outlet to diminish rippling of the ribbon sandwich containing speckles which can cause air entrainment (when vacuum is not employed). Also it^is preferred that the outlet shape match the ribbon shape (usually flat rectangular) and be 15 oriented with it to minimize obstructions to dentifrice withdrawal from the walled vessel, and so to minimize holdup time, air entrapment, and speckle binder solubilization. The speckles to be added to the dental gel in prescribed proportion are contained in a hopper 230 of a control-20 lable flow rate feeder 232, preferably of a helix type, including speed control and motor combination 234, which feeder discharges the speckles at a desired controlled rate through an outlet of a tube 236 onto a distributor 238, which spreads them out so that as they leave it they form a 25 falling stream or thin curtain which matches in size and orientation the ribbons produced by nozzles 229 and 233. Instead of a helical feeder, other feeders of the screw, belt and vibratory types are also useful. Line 228 connects - 30 - 2 019 4 5 to a vacuum source, which, like vacuum line 259 may or may not be activated or connected. Valves 239 and 241 are provided to selectively allow dropping of the product through line 243 or communication 5 with pump 245, which is preferably of the Moyno type. Screw pump 245, powered by motor 247, pumps the product in a gentle manner through line 249 to static mixer 251, preferably of the Kenics type, where it is gently blended without disintegration or solubilization of the speckles therein, and is 10 uniformly mixed. It then passes through line 253 to a receiver 255, which may be feed tank for a tube filling machine, not illustrated. Although the apparatus of the invention may be "•v . used and the process thereof may be practiced without 15 employing vacuum, often it will be desirable to avoid the intrusion of air into the dental materials and the entire operation or any part of it may be under vacuum. Desirably, the speckles feeder and speckles "applicator" will be under vacuum and accordingly, vacuum lines or taps 259 and 228 are 20 indicated in the drawing. In FIG. 5 gel feeding means 229 and 233 include nozzle portions 275 and 277 having restricted flat openings 263 and 265, respectively, with the nozzle portions, as illustrated, having connected to them supporting guides 267 and 269, 25 respectively, which may be adjustable, and which facilitate proper directings of the ribbons or webs of gel so that the curtain or screen of speckles may fall on them correctly. The gel ribbon on guide 267 is designated by numeral271 and is shown without speckles having been deposited on it. A - 31 - 20194 similar, ribbon 27? on guide 269 discharges its gel ribbon below the discharge from the first guide,, and near' to the outlet from the vessel. Preferably, the curtain of speckles drops vertically or substantially vertically onto gel ribbon 5 271 after that ribbon has left the guide 267 but while it is still moving.in a direction with a horizontal component, e.g., at 60° from the horizontal. However, if care is exercised some speckles can be dropped onto gel 271 while it is still in contact with the support. As the gel ribbon 271 10 with adherent speckles falls vertically or substantially vertically it contacts ribbon 272 and the two ribbons sandwich the speckles between them. To avoid rippling, which can cause air entrapment, guide 269 may preferably extend, either straight or as a convex curve, to near (usually within 5 to 15 25 cm.) of the outlet opening from the vessel and the gel ribbon passes through the oriented and similarly shaped outlet without rippling, with the discharge rate being kept the same as the sum of the addition rates. The rates of feeds (and thicknesses) of the gel ribbons may be about the 20 same or may be varied with such relative rates usually being within the 1:4 to 4:1 range. The controlled and proportioned feed of discrete speckles passes from delivery tube 236 onto distributor 238, which is shown in the form of an expanding shute, including side walls 279 and281, bottom 25 283 and dividing pegs 285, located in "Pascal's triangle" arrangement. The speckles and the gel feeding means and the openings in the discharge "nozzle" portionsc£ such gel - 32 - feeding means may be adjustable/ as described with respect to FIG. 3. The first or upper stream or ribbon of gel is directed so that the stream or curtain of speckles, usually 0.5 to 5 mm. thick, may fall on it correctly, preferably when the speckles 5 are falling substantially vertically and the gel is moving in a direction with a horizontal component, so that the gel passes under the falling speckles, which contact it and adhere to it. The gel ribbon 271 is shown falling downwardly and to the right, while speckles 273 fall onto it from distributor 238 10 of directing means 235 (FIG. 4), and ribbon 272 falls downwardly and to the left below ribbon 271. The described apparatuses of FIG'S. 2-5 and the corresponding processes^allow the manufacture of speckled dentifrices to be effected efficiently and quickly without 15 the need for the use of any conventionally shearing mixing apparatus. Also, the speckles do not clump together and neither are they disintegrated, and because the process is a speedy one the product is quickly processed and may be filled into tubes before any appreciable softening or solubilizing 20 of the dentifrice binder occurs. Thus, the preferred clear gel dentifrice, usually with individually visible, separate functional speckles attractively distributed therein, is obtained, without any clouding of it due to breaking up of speckles and distribution of the finely divided functional material, such 25 as polishing agent, through the dentifrice. Other advantages of this invention include the immobilization of the speckles with respect to the gel ribbon, - 33 - 7 019 4 5 and resulting lesser dissolving of any binder utilized in any solvent materials that may be present in the gel. The feeding of the gel in an arc that becomes vertical above a vessel outlet after the speckles have been deposited diminishes 5 residence time in the apparatus before removal and thereby diminishes such dissolving of the binder for the speckles and prevents disintegration of the speckles. Also, the sandwiching effect, as illustrated in FIG'S. 4 and 5, results in an even better distribution of speckles in the dental 10 material, and is especially good for dental compositions to which the speckles are not strongly adhersent. In accordance with a broad process aspect of the invention, the manufacturing of a dentifrice containing dispersed "s. discrete speckles therein comprises producing a stream of a gel 15 or paste dental composition containing a gelling agent which helps to make the surfaces thereof adhesive for the speckles, which dental composition constitutes a major proportion of the dentifrice, producing a stream of speckles to be distributed throughout the dentifrice, directing said stream of speckles onto 20 a surface of the stream of the dental composition and controlling the relative feed rates and the proportions of the streams of dental composition and the speckles to be dispersed in the dentifrice so that when the stream of speckles contacts the stream of dental composition the speckles are insufficient to cover the 25 dental composition surface, so that the speckles adhere to the dental composition stream and there is produced a dentifrice containing the speckles in desired proportion distributed in it. - 34 - 7-019 An apparatus for carrying out the described process comprises means for producing a moving or flowing stream of a dental composition, which is usually a dentifrice except for speckles to be distributed therein, and is of such a nature that the 5 speckles will adhere to it. In such an apparatus a stream or ribbon of dental gel is produced by forcing it through an appropriate orifice so that it is extruded from said orifice in desired shape, preferably as a flat ribbon, the stream or curtain of speckles is of particle sizes within the 10 No. 10 to 80 sieve range, U.S. Sieve Series, said speckles are directed onto the gel ribbon in such manner as to be distributed evenly over the inner portion of the surface of the flowing . ribbon so as to adhere to said ribbon, and the ribbon of gel with adherent speckles thereon is collected in a walled 15 vessel from which it is continuously removed as more gel containing speckles is added thereto or created therein. In preferred embodiments of the invention the speckles are sandwiched between dentifrice ribbons and the speckles are formed into a uniform falling curtain by means of a Pascal's 20 triangle arrangement of barriers. The following examples illustrate but do not limit the invention. Throughout the specification, including the working examples, and in the claims, all parts are by weight, unless otherwise indicated. - 35 - ^J) ^ A f-\ EXAMPLE 1 - Five parts of ethyl cellulose(10 centipoises), of the physical characteristics described previously in the specification and in powder form, are dissolved in five 5 parts of ethanol (95%) and are mixed in a Hobart mixer with 95 parts of calcined alumina (Microgrit WCA 9F) of particle sizes in the range of 0.5 to 10 microns and an average particle size in the range of 3 to 5 microns. Mixing is continued for about four minutes until the blend is uniform, 10 after which the mix is forced through a No. 10 (U.S. Sieve Series) screen and the "extruded" material is oven dried for one hour at 65°C. The dried agglomerates are then screened through a No. 30 screen and the cut that rests on a No. 60 screen, the dried speckles comprising the calcined alumina 15 and ethyl cellulose, is collected. The speckles produced are of angular shapes, with the ratios of maximum length to maximum width usually being within the 1 to 2 range and most of the particles being of such a ra.tio within the 1.1 to 1.5 range. The angularity of the particles may be a factor in 20 making the dentifrices so attractive in appearance, at least for some consumers. A transparent (or translucent) dentifrice base (all components except speckles), is made of the following formula: - 36 - 2 01945 10 15 20 25 Component Glycerol (99.3% pure) Sodium carboxymethyl cellulose Sorbitol (70% aqueous solution) Polyethylene glycol 600 Water Sodium saccharin Sodium benzoate Blue dye (FD&C Blue No. 1, 1% aqueous solution) Parts by Weight 25.00 0.35 36.04 3.00 3.00 0.25 0.50 0.20 Sodium monofluorophosphate (1 to 60 microns) Silicon dioxide (Zeo 49) Synthetic silica (Syloicl 244) y Sodium lauryl sulfate 1 Flavor (spearmint, peppermint, wintergreen, clove, etc., as desired) 0.76 18.00 5.50 1.20 1.20 9b.00 Five parts of the described speckles, with particle sizes -30 +60 (U.S. Sieve Series), are gently blended in a slow moving mixer (about two r.p.m.) with 95 parts of the described dentifrice base, after which the mix is deaerated and .automatically filled into capped collapsible tubes which are then sealed. During the mixing, dearation and tube filling steps the speckles, which are substantially evenly distributed through the dentifrice, remain discrete, independent and undissolved in the dentifrice base so that when the tube is opened, after filling, and preferably, after - 37 - 201945 storage for about a month, and the dentifrice is squeezed through the discharge opening thereof, the speckles appear to have retained their initial integrity, contrasting with the bluish gel. When the product is evaluated immediately after filling, and without being stored, the speckles are palpable but, upon storage before use, for periods from two weeks to a year or more, are sufficiently,softened, as by solubilization of the ethyl cellulose by the flavoring oil, sometimes with the aid of the dental detergent or other surface active agent that may be present, and other components, so as to appear distinct and not "smeared", but yet to be satisfactorily impalpable. During toothbrushing with the dentifrice the speckle particles are readily reduced in size, are not irritating to the gingiva, and are readily dischargeable from the oral cavity on completion of brushing. Although the presence of the anionic detergent in the dental base may be of assistance, it is thought that the controlling component of such base is the 1.2% of flavoring agent present. A proportion of such an agent or a mixture thereof from 0.5 to 2%, preferably 0.8 to 1.5%, of which at least half is normally active as a solvent for ethyl cellulose, is desirable for best speckle dispersions, and the flavor will usually include over 50% and often over 80% of solubilizing hydrocarbons, esters, alcohols and aldehydes. - 38 - 101^4 The manufacturing method described for the dentifrice, in which the speckles are dispersed in the body of the gel, is one in which the mixing operation should be watched to make sure that the speckles are not disintegrating and, at any sign of this happening mixing should be halted and, providing that the dentifrice appearance is not significantly adversely affected, usually by being made unaccept-ably cloudy, filling of the tubes should be undertaken promptly. Instead of employing the described mixing method it will often be preferable to utilize other processing techniques, previously referred to herein, wherein a regulated even "fan" of speckles is deposited by means of gravity on a continuously falling extruded ribbon of gel, to which the '•n» . speckles adhere, so as to obtain uniformity of distribution of the speckles in the dentifrice. When the speckled dentifrice of this invention is packed in a collapsible aluminum tube the speckles in the dentifrice are not visible until discharge from the tube but at that time they are maintained discrete in the toothpaste extruded and impart to it an attractive and distinctive appearance. However, when instead of the normal aluminum tube's one employs resilient transparent tubes, such as tubes of polyvinyl chloride or other suitable polymer, the speckles can be seen through the tubes and through the transparent gel dentifrice base, and their movements, oh discharge, can be observed. This provides an additional aesthetic benefit and helps to make toothbrushing more interesting, especially for children. Additionally, the functional speckles act as a reminder to the person using - 39 - 2 019 4 5 the dentifrice of the presence of polishing agent or other functional constituent in the dentifrice and thereby help to remind him of the importance of brushing so that such component may be effective. 5 The formula given above is one for a gel dentifrice in which the normal 41.04% of sorbitol solution had been reduced to 36.04% to allow for the introduction of the 5% of speckles. The effect of this change in the formulation is to maintain the percentages of the other dentifrice 10 components the same as in an unspeckled product, with the exception of the major component, the sorbitol solution. It is considered that with other variations in the contents of speckles in such dentrifrices such procedure for modifying the formula may continue to be followed. However, it is 15 also feasible to start with the initial gel formulation, e.g., containing 41.04% of sorbitol solution,and reduce each of the components proportionately to allow for the introduction of the desired percentage of speckles. In a variation of the above described experiment 20 1% of ultramarine blue pigment may be employed in place of 1% of the Microgrit, so that the speckles are of a definite blue coloration. In place of the described proportion of ultramarine blue one may use 0.5 to 2.0% of that pigment or mixtures of pigment(s) and polishing agent(s) of propor-25 tions from 1:10 to 10:1 may be used. Alternatively, about 0.1 to 1% of any suitable water insoluble (or oil soluble) dye may be employed. In such cases the dye solution may be omitted from the dentifrice base formula or may be present, - 40 - providing enough contrast between the speckles and the base is obtainable. Of course, the various components of the formula may be replaced by others, such as those previously described, and useful products will also be obtained. For example, the different mentioned pigments and dyes may be employed, the sodium lauryl sulfate may be replaced by sodium ethoxyJated higher fatty alcohol sulfate or sodium hydrogenated coconut oil fatty acids monoglyceride monosulfate, and the polishing agents may be replaced by dicalcium phosphate dihydrate and/or dicalcium phosphate (anhydrous) or mixtures thereof. Proportions of the various components may be modified ±10%, ±20%, and ±30%, so long, as they are maintained within the ranges previously recited, and the results are satisfactory products of similar properties, although those of the proportions of this example are preferred. EXAMPLE 2 75 Parts of anhydrous dicalcium phosphate and 15 parts of dicalcium phosphate dihydrate, both having average ultimate particle sizes of about 4 microns, are mixed with 10 parts of ethyl cellulose and 10 parts of ethyl alcohol in a Hobart mixer. Alternatively, and preferably, ethanol and ethyl cellulose may be premixed and then may be admixed with a previously made blend of the dicalcium■phosphates. The mass formed is forced through a screen having uniform openings of 2,000 microns and is then oven dried for one hour at 65°C. The dried agglomerates are then screened through a screen having uniform openings of 420 microns and those agglomerates - 41 - which do not pass through a screen having uniform openings of 177 microns are collected. Next, the agglomerated functional particles resulting are mixed with a dentifrice base of the formula given in Example 1, with the exception that the polishing agent in such base is replaced by sodium aluminosilicate, such as that marketed under the trade name Zeolite 4A, and the percentage of speckles in the final product is 2% (with the sorbitol solution present being increased by 34). . In variations of this formula there may be substituted for the polishing agent of the speckles, hydrated alumina having an average particle size less than about 10 microns, calcium carbonate having particles substantially '•v. all of which are less than about 7.4 microns in diameter, or insoluble sodium metaphosphate having an average particle size of about 5 microns (all such sizes being ultimate particle sizes). The dentifrices of this example are speckled, transparent or translucent products and are aesthetically pleasing in appearance. The visible particles of the agglomerated polishing agents (for which other functional insoluble materials may be substituted in whole or in part) are substantially uniformly dispersed in the dentifrice base as visibly separate entities and are not substantially impalpable upon use, after three months' storage. - 42 - 0 1 9 45 EXAMPLE 3 Instead of dissolving the ethyl cellulose in the ethanol or other suitable solvent, agglomerates are made by blending the polishing agent and ethyl cellulose, sometimes 5 with a reduced proportion of ethanol present, to form a powder blend. Such blend is compressed in a rotary tablet press to form slugs, about 6 mm. thick and 25 mm. in diameter. The slugs are then granulated in an oscillating granulator to form smaller particles, preferably such as 10 will pass through a No. 30 screen and rest on a No. 60 or No. 80 screen. This technique for making the speckles may also be applied to any of the speckle formulas given in the preceding examples. Although the binding effect of the ethyl cellulose might not be as great, the products of this 15 example are also satisfactory for incorporation in dentifrices to contribute their aesthetic advantages and functional effects. If the binding effect of the ethyl cellulose in the foregoing formulas is not sufficient, the proportion thereof present may be increased, sometimes up to 100 or 200%, but such 20 increases involve additional expenses and therefore the "wet" method, in which solutions of ethyl cellulose in ethanol or other suitable solvents are employed, is often preferred. 25 - 43 - ^ f\ % c EXAMPLE- 4 95 Parts of calcined alumina (Microgrit WCA 9F) of particle sizes in the range of 0.5 to 10 microns and an average particle size in the range of 3 to 5 microns are blend-5 ed with three parts of powdered polyvinyl pyrrolidone, obtained from GAF Corp., and marketed by them under the designation Plasdone K-29-32. Two parts of ethyl cellulose powder of the type mentioned in Example 1 are dissolved in five parts of ethanol (95%) and the PVP - alumina blend is mixed with the 10 solution in a Hobart mixer. Mixing is continued for about four minutes until the blend is uniform, after which the mix is forced through a No. 10 screen and the "extruded" material is oven dried, as described in Example 1. The dried agglomerates are then screened and collected, as described in 15 Example 1. The speckles produced are of angular shapes, with the ratios of maximum length to maximum width usually being like those of Example 1. A transparent (or translucent) dentifrice base (all components except speckles) is made like that of Example 1, except for the presence of 39.04 parts of 20 sorbitol solution instead of 36.04 parts thereof. Two parts of the described speckles, with particle sizes -30 +60 (U.S. Sieve Series), are gently blended in a slow moving mixer (about two r.p.m.) with 98 parts of the described dentifrice base, after which the mix is deaerated 25 and automatically filled into capped collapsible tubes which are then sealed. The processing employed is like that described in Example 1. When the product is evaluated - 44 - immediately after filling, and without being stored, the speckles are palpable but, upon storage before use, for periods from two weeks to a year or more, they are sufficiently softened to be impalpable, as by solubilization of the PVP by the moisture 5 present and solubilization of the ethyl cellulose by the flavoring oil, both solubilizations apparently sometimes being with the aid of the dental detergent or other surface active agent that may be present, and sometimes assisted by other components, too. 10 When the proportion of flavor in the dental gel base is decreased to 0.6%, half that of the above formula, the PVP - ethyl cellulose binder system for the speckles still is effective and they are satisfactorily impalpable on storage. It is also effective when the flavor concentration is varied to 15 0.3%, 0.9% and 1.5%. However, the greater proportions of flavor (and/or other lipophile solvents) may cause somewhat earlier solubilization than preferred, in which case the proportions of PVP and ethyl cellulose will preferably be varied, to 2 parts PVP and 3 parts ethyl cellulose, for 20 example. Similarly, if the palpability of the speckles should increase to more than desired they may be made softer by increasing the PVP proportion, e.g., to twice the ethyl cellulose. The concentrations of speckles and the sizes thereof may be changed, within the ranges previously 25 given. Also,others of the materials previously listed may be substituted for the alumina polishing agent, including other types of water insoluble functional substances. - 45 - 2 019 4 5 The variations in formulations and procedures described in Example 1 are also applicable to this example and the products obtained are also useful speckles and speckled dentifrices. 5 EXAMPLE 5 75 Parts of anhydrous dicalcium phosphate and 15 parts of dicalcium phosphate dihydrate, both having average ultimate particle sizes of about 4 microns, are mixed with 5 parts of ethyl cellulose, 5 parts of PVP and 10 parts of 10 ethyl alcohol in a Hobart mixer. Alternatively, and preferably, ethanol and ethyl cellulose may be premixed and then may be admixed with a previously made blend of the dicalcium phosphates with PVP. The mass formed is forced through a screen having uniform openings of 2,000 microns and is then 15 oven dried for one hour at 60°C. The dried agglomerates are then screened through a screen having uniform openings of 420 microns and those agglomerates which do not pass through a screen having uniform openings of 177 microns are collected. Next, the agglomerated functional particles resulting are 20 mixed with a dentifrice base of the formula given in Example 4, with the exception that the polishing agent in such base is replaced by sodium aluminosilicate, such as that marketed under the trade name Zeolite 4A. The dentifrices of this example are speckled, 25 transparent or translucent products and aesthetically pleasing in appearance. When formula and processing variations are made, as in Example 2, good products also result, of the desired properties. - 46 - 20194 EXAMPLE 6 The functional polishing agent constituent of Example 5 is replaced by a mixture of ten parts of anhydrous dicalcium phosphate and 90 parts of calcium carbonate, with the same total proportion of polishing agent being employed; otherwise the same procedure is followed. The products resulting are similarly satisfactory in functional effects and are aesthetically pleasing in appearance. Similar results are obtained when different mixtures of the disclosed polishing agents are substituted for the present mixture in the speckles, and when proportions thereof are varied. i EXAMPLE 7 Instead of dissolving the ethyl cellulose and PVP in ethanol or other suitable solvent, agglomerates like those of Example 6 are made by blending the polishing agent, PVP and ethyl cellulose, sometimes with a reduced proportion of ethanol present, to form a powder blend. Such blend is compressed in a rotary tablet press to form slugs, about 6 mm. thick and 25 mm. in diameter. The slugs are then gra'nulated in an oscillating granulator to form smaller particles, preferably such as will pass through a No. 40 screen and rest on a No. 60 or No. 80 screen. Although the binding effects of the PVP and ethyl cellulose might not be as great, the products of this example are also satisfactory for incorporation in dentifrices to contribute their aesthetic advantages and functional effects. If the binding effects of the PVP and ethyl cellulose in the foregoing formulas are not sufficient, the proportions thereof present may be increased, sometimes - 47 - up to 100 or 200%, but such increases involve additional expenses and therefore the "wet" method, in which solutions of PVP and ethyl cellulose in ethanol or other suitable solvents are employed, is often preferred. EXAMPLE 8 In the preceding examples, the polyvinyl pyrrolidone, the water soluble binder portion of the combination binder, is partially replaced (50%) or entirely replaced by the following water soluble binders: gum acacia, gelatin, corn starch, sodium carboxymethyl cellulose, sodium alginate, polyvinyl alcohol, carrageenan, xanthan gum and gum tragacanth. The speckles made, when incorporated in gel dentifrices like those previously described in these examples, sufficiently retain their individuality and integrity during processing but become impalpable on storage in the dentifrice, while still retaining their original shapes, in the same manner as the speckles made with PVP - ethyl cellulose combination binders. However, it is considered that the PVP - ethyl cellulose combination binder is generally superior in its combination of desirable features, including processing stability, compatibility with dentifrice components, and conversion from palpability to impalpability without loss of speckle integrity and without significant change in appearance. EXAMPLE 9 Speckles of various compositions are compared to those based on ethyl cellulose and PVP. The invented speckles are made in generally the manner as described in Example 4, by the wet method, and the speckle formula includes 95% of calcined alumina, 2% of ethyl cellulose and 3% of PVP, with such materials - 48 - 0 1 9 4 5 being the same as those used in Example 4. The speckles of the comparative experiments are also made by the wet method, except \ for one type, which will be indicated, which was made by the dry or "slugging" method of Example 7. slide with another slide, and noting the time of physical change and the type of physical change in the granules. 10 When 2% of sodium carboxymethyl cellulose is employed as the binder the speckles lose integrity within fifteen seconds, which is also the case with the speckles bound with 2% of hydroxypropyl methyl cellulose, but that takes two minutes. Speckles made with a binder comprising 2% of methyl cellulose 15 and 3% of PVP soften, swell and lose integrity after about two minutes and when 5% of PVP is employed as the sole binder speckles made with it soften after eight minutes. When the binder is 1% of methyl cellulose (400 centipoises), the speckles lose integrity after a little more than five 20 minutes and when the binder is changed to 10% of polyethylene glycol 6,000, with 1% of magnesium stearate, with the speckles bein'g made by "slugging", they lose integrity after nineteen minutes. The "control" speckles of this invention, including 2% of ethyl cellulose and 3% of PVP, when subjected to the 25 same test, are still intact after over six hours. 5 The speckles were tested by weighing out 100 milligrams of each type, separately placing them on glass slides, adding to each four drops of water, covering each - 49 - 2 C * 9 4 5 EXAMPLE' 10 In a process of this invention in which the apparatus of FIG'S. 2 and 3 is employed, a speckled clear gel dentifrice is made of the formula and by the method described in Example 1. 5 The various gel (or paste) components are mixed together in mixer ill and are pumped, preferably by a Moyno type pump, to the extruder, which terminates in a flat "slit" nozzle, as illustrated,with a relatively narrow rectangular opening. Preferably, such a nozzle will be inclined downwardly from 10 the horizontal at an angle of about 10 to 45°, e.g., 30°. The feed rate of the speckle feeding mechanism, an Acrisan helix feeder, is adjusted to correspond to the gel feed rate. Thus, when, for example, a 3% speckle content in the dentifrice is desired, if the feed rate of the 15 gel is 3 kilograms per minute, then the speckles will be fed at the rate of 93 grams per minute. Conventional electronic or mechanical means may be employed to maintain the desired feeds ratio, or to adjust it if changes in such proportions are desired for different products. 20 In the drawing the feeding mechanism for the speckles is shown only schematically in FIG. 2 and only the end thereof is shown in FIG.. 3 but various types of feeds, including screw, belt, weighing belt, electronically controlled gravimetric feeders, and others may be used and the dis-25 charge pattern may be changed. " The discharge will be such that few, if any, speckles will fall past the gel and the gel stream will hold the impinging speckles. Also, the speckles will fall separately and the gel will be moving fast enough - 50 - 2 019 4 5 underneath them, at a speed usually of 10 to 100 cm./second, e.g., 20 to 50 cm./sec., that individual speckles strike the gel and adhere to it, with very few hitting other held speckles and bouncing off them. Also, all. or almost all of such bounc-5 ing speckles will subsequently adhere to the dental composition. The falling speckled gel, with the speckles adherent to it, does not remain for a long period of time in the walled vessel in which or above which the speckling apparatus is located because it drops through the center of such vessel 10 and most of it proceeds almost directly to the outlet. This short residence time in the "speckling vessel" is highly desirable and helps to maintain the integrity of the speckles in the dentifrice. WhiJ.fi residence times in the vessel may vary, typical times are in the range of 20 seconds to 2 minutes, 15 the shorter the better. Such quick throughput, the absence of mobile speckles and the central gel discharge from the vessel also help to avoid aggregation of speckles into objectionable clumps. The additional volume of the walled vessel is for holding gel which may be fed into it during 2o periods when filling equipment may be temporarily halted and before feed to the vessel can be stopped. Thus, often the walled vessel may contain only a small proportion of speckled gel, e.g., 10 to 25% of its volume. Alternatively, other material may act as a "wall" bounding the speckled gel, within the vessel. 25 After leaving the speckling vessel the gel is gently pumped by a Moyno type pump and passes through a static mixer, to assure complete mixing. The preferred static mixer, a Kenics mixer, is like that described in the - 51 - 201945 March 19., 1973 edition of Chemical Engineering in an article entitled Handling Viscous Materials - Motionless Mixer for Viscous Polymers. Although it is desirable to utilize a mixer prior to discharging the gel to a filling machine or 5 suitable container before such machine, the present process and apparatus, without such mixer, can often sufficiently distribute the speckles throughout the gel so that in some instances the mixer is not employed. The conditions of operations are not considered to 10 be critical but usually the vacuum employed will be within the range of about 300 to 700 mm. of mercury, e.g., 400 to 600 mm. Hg. Temperatures may be about room temperature or higher, e.g., in the range of 10°to 40°C. The pressure of N. extrusion of the gel varies with the gel viscosity but from 15 0.03 to 0.7 kilogram per square centimeter is considered to be a reasonable range. The various pieces of equipment of this invention, because they are employed in processing an oral product, should be constructed of non>-corroding and safe materials. 20 It has been found that stainless steel components are highly preferable and the mixers, extruders, pumps and valves, and any other parts that contact liquid or gel materials, will preferably be made of stainless steel, such as is normally employed in the food processing industry. 25 When a 2% speckled clear dentifrice (containing silicon dioxide, sorbitol, glycerol, CMC, sodium lauryl sulfate, flavor and water in the gel, and alumina and ethyl cellulose in the speckles), like that described in Example 1, - 52 - 2 019 4 5 is made with the apparatus described herein, the product resulting will be just as desired, with the speckles being regularly distributed throughout the clear gel and with no cloudiness or disintegrated speckles noted. Similar results 5 are obtainable when other speckled dentifrices, such as those of the prior art and of Examples 2-9, are produced, utilizing the apparatus and process of this invention, as illustrated. In practicing the inventive process, while it will 10 be preferred for the dental gel or paste to be in flat ribbon form, it is understood that variations of such form may be utilized, such as arced ribbons and even cylindrical or tubular streams. Also, while it is preferred that the stream or curtain of speckles be a suitably thin straight 15 curtain of such material, e.g., 0.1 mm. to 1 cm., e.g., 0.5 to 5 mm., in thickness, falling by gravity, the speckles may be forcefully directed onto the dentifrice. For example, in some instances, a vertically moving stream of dentifrice may have speckles directed onto it horizontally, with those 20 not adhering being collected for recycling. The' dental material stream may be given a rotary motion so that it "picks up" about its entire exposed surface speckles unidirectionally aimed at it. Conveyed speckle particles can impact a gel stream and deposit on it, immobile and 25 discrete. Yet, while such variations of the invention are operative, the process described and illustrated herein is considered to be superior. The proportion of speckles fed to the moving - 53 - ^ f■ 1 9 4 5 ribbon or web of gel dentifrice will be a minor proportion, compared to the complete dentifrice containing speckles, and compared to the gel fed.. The feed rate for the speckles will usually be adjusted so that the amount of speckles directed onto the gel will be insufficient to cover it and preferably will be insufficient to cover more than half the area of the portion of the gel exposed to the curtain of speckles when such curtain contacts the gel. While, as was mentioned previously, different ways of adhering the speckles to the gel ribbon have been mentioned, it is highly preferable that the speckles be dropped vertically in a curtain onto a ribbon of gel, with the gel moving in a direction with a horizontal component. Such direction may be horizontal or have a significant horizontal component with the gel falling after having picked up the speckles, but normally an inclination from the horizontal, e.g., 10 to 60°, will be preferred for the gel, with the speckles falling vertically, after having been discharged from a delivery apparatus. The viscosity of the gel is not critical, so long as the speckles sufficiently adhere to it, and the sizes of the particles are not critical, but normally they are in the No's. 10 to 80 sieve size range, preferably 30 to 80, and more preferably 30 to 60. The speckles are preferably sharp edged and in falling onto the gel stream they become partially embedded therein, immediately being rendered immobile, but similar good results may also be obtained when rounded speckles are used. Although the speckles used are preferably visible in a clear gel, which makes the product aesthetically attractive, they may be of - 54 - 201945 an index of refraction which renders them invisible. Thus, the designation "speckles" includes visible and invisible discrete particles of various materials, with agglomerates of finely divided polishing agents being preferred. Also, while it is preferred that they be agglomerates of finely divided polishing agent and binder they may comprise other "active" components, such as therapeutic agents, colorants, flavors and fluorides. It is contemplated that the dentifrice material on which speckles are deposited will be all the dentifrice, except speckles, but this is not necessary. It is possible that some dental components may be blended in with the other dentifrice materials after addition of the speckles. For example, it may be desirable to blend in the flavoring, which may contain some volatile components, before the Kenics mixer but after any application of vacuum to the product during the depositing of the speckles. Such a procedure has the advantages of preserving the flavor and preventing losses of more volatile components thereof due to the application of the vacuum in the speckling operation, and any flavor components which would solubilize the binder of the speckles would have less processing time contact with them. Yet,'the Kenics or other relatively low shear static mixer would blend the flavoring sufficiently evenly throughout the dentifrice. Similarly, other components, usually minor adjuvant components, may be added to the .dentifrice subsequent to the incorporation of the speckles therein. - 55 - 2019 45 The walled vessel mentioned, into which the speckled dentifrice falls, may be under vacuum or may be open to the atmosphere. The speckling apparatus may have a reservoir underneath it, rather than being enclosed in a vessel. How-5 ever, it is preferred that such equipment be covered and under vacuum, when air entrapment would otherwise be a problem. It acts as a container for the speckling apparatus, in addition to being a vessel to hold the resulting product. The present process and apparatus lend themselves to use for 10 making a variety of different dentifrice formulas containing different proportions of speckles. To vary the speckles concentration is a simple matter, since it involves only changing the speed of the speckles feeder and controlling the gel feed rate accordingly. 15 Among the various advantages of the invention are increased efficiency of operation, diminution of employment of moving part mixers and the stabilization of the dental gel or paste. It is known that various dentifrices are thinned by excessive mechanical working and the present 20 blending operation for adding speckles to.the dentifrice avoids such working and allows maintenance of the desired viscosity of the dental gel. EXAMPLE 11 A process for making a speckled. dentifrice is 25 carried out as in Example 10 but the apparatus employed is that illustrated in FIG'S. 4 and 5. Therefore two gel ribbons are produced, each with half of the total dentifrice - 56 - 2019 45 (less speckles) in it. The flat" slit nozzles are inclined downwardly at about 30° from the horizontal. The gel speed will be about 20 to 50 cm./second and the gel will preferably be adhesive enough and conditions will be so controlled that 5 most of the speckles striking the first gel stream will adhere to it, with the balance (or essentially all the balance) being sandwiched in place by the other gel stream. The speckle feed, as shown in FIG. 5, is a shute with pegs located thereon in Pascal triangle arrangement. It 10 is downwardly inclined at an angle of about 30° from the horizontal, and is about 90% of the width, at the delivery end, of the gel streams. Of course, while the Pascal triangle arrangement of pegs is preferred other feeders may also be employed. The dentifrice resulting has all the advantages 15 of that of Example 10. Additionally, the process and apparatus of the present example are expecially suitable for holding speckles to the gel dentifrice in ordered arrangement and uniform distribution therein when the gel is not strongly adhesive. Thereby "bouncing off" of the speckles is avoided, 20 saving losses of speckles and the need to recycle or scrap unadhered speckles. Additionally, even with non-adhesive gels (and/or non-adherent speckles) the final product can be controlled so as to have a consistent and desired content of the speckles therein (because speckle losses are minimized). 25 The present invention has been described with respect to various examples and preferred embodiments thereof but is not to be limited to these because it is evident that one of skill in the art, with the present specification before him, would be able to utilize substitutes and equivalents without departing from the invention. - 57 - </div>

Claims

<div class="application article clearfix printTableText" id="claims"> 20 f 9 4S WHAT WE CLAIM IS:

1. Functional agglomerated speckles, for incorporation in dentifrices, whic^ comprise agglomerates of a water insoluble powdered functional material and water insoluble, ethanol soluble ethyl cellulose.

2. Speckles according to claim 1 wherein the water insoluble powdered functional material is a dental polishing agent which constitutes a major proportion of the speckles, and wherein the ethyl cellulose is a minor proportion of the speckles.

3. Speckles according tc claim 2 wherein the water insoluble dentals-polishing agent is selected from the group consisting of dicalcium phosphate, tricalcium phosphate, insoluble sodium metaphosphate, alurr.ina, silica, magnesium carbonate, calcium carbonate, calcium pyrophosphate, bentonite and zirconium silicate, and mixtures thereof, of particle sizes in the range of 0.5 to 20 microns, and the speckles are of sizes to pass through a No. 10 U.S. Sieve Series « sieve and be retained on a No. 80 sieve.

4. Speckles( according to claim 3 wherein the dental polishing agent comprises 75 to 98% of the speckles, the ethyl cellulose comprises 2 to 20% thereof and coloring agent, when present, comprises up to 5% thereof. 201945

5. Speckles according to claim 4 which comprise 85 to 97% of the dental polishing agent, 3 to.15% of ethyl cellulose, and 0.1 to 1% of coloring agent, and which are of such particle sizes that they.pass through a No. 3 0 U.S. Sieve Series sieve and are retained by a No. 00 sieve.

6. Speckles according to claim 1 which comprise a water soluble binder.

7. Speckles according to claim 6 wherein the water soluble binder is polyvinyl pyrrolidone (PVP), and the combination binder, including the water insoluble, ethanol soluble ethyl cellulose and the PVP, is a minor proportion of the speckles.

8. Speckles according to claim 7 wherein the ratio o£ ethyl cellulose to PVP is within the range of 1:10 to 10:1 by weight.

9. Speckles according to claim 8 wherein the water insoluble dental polishing agent is selected from the group consisting of dicalcium phosphate, tricalcium phosphate, insoluble sodium metaphosphate, alumina, silica, magnesium carbonate, calcium carbonate, calcium pyrophosphate, bentonite and zirconium silicate, and mixtures thereof, of particle sizes in the range of 0,5 to 20 microns,, the speckles are of sizes to pass through a No. 10 U.S. Sieve Series sieve and be retained on a No. 80 Sieve, and in the speckles the ratio of ethyl cellulose to PVP is within the range of 1:5 to 20194s"

10. Speckles according to claim 9 wherein the dental polishing agent comprises 80 to 98% of the speckles, and in the binder the ratio of ethyl cellulose to PVP is within the range of 1:2 to 2:1.

11. Speckles according to claim 10 which comprise 85 to 97% of the dental polishing agent and 3 to 15% of the combination binder, which are of such particle sizes that they pass through a No. 30 U.S. Sieve Series sieve and are retained by a No. 80 sieve, and in which the ratio of ethyl cellulose to PVP is within the range of 1:2 to 1:1.

12. Speckles according to claim 11 which comprise 90 to 97% of calcined alumina, as the dental polishing agent, and 3 to 10% of the combination binder, and in which the ratio of ethyl cellulose to PVP is about 2:3.

13. A process of making speckles for incorporating in dentifrices which comprises moistening a water insoluble functional powdered material, for incorporation in a dentifrice, with a solution of water insoluble ethyl cellulose in a I volatile solvent, compacting the moistened powder, • converting it to particulate form, drying the particles and collecting those that pass through a No. 10 U.S. Sieve Series sieve and are retained on a No. 80 sieve. - 60 - 7 0 19 45 •

14. A process according to claim 13 which comprises mixing a powdered water soluble binder with a water insoluble functional powdered material, for incorporation in a dentifrice, dissolving water insoluble ethyl cellulose in a volatile 5 solvent to make a solution, moistening the mix of water soluble binder and functional material with the solution of ethyl cellulose, compacting the moistened powder, converting it to particulate form, drying the particles and collecting those that pass through a No. 10 U.S. Sieve Series sieve and 10 are retained on a No. 80 sieve.

15. A dentifrice comprising water, humectant, gelling agent, detergent and flavor, all of which are constituents of a gelled vehicle of the dentifrice, and a dental polishing agent, uniformly distributed throughout the 5 vehicle, and visible functional speckles distributed through the dentifrice which are agglomerates of a water insoluble powdered functional material and water insoluble, ethanol soluble ethyl cellulose binder. •

16. A dentifrice according to claim 15 which is *;in the form of a transparent or translucent gel, with the speckles visible therein and in which the speckles comprise from 0.1 to 10% of the dentifrice.;- 61 -;201945;17. A dentifrice according to claim 16 which comprises 5 to 40% of glycerol, 5 to 50% of sorbitol, 5 to 30% of water,.0.1 to 5% of gelling agent, 0.5 to 5% of dental detergent, 0.5 to 2% of flavoring agent and 10 to 40% of water insoluble dental polishing agent, in a continuous phase, and 1 to 3% of speckles which are of sizes in the No's. 10 to 80 range, U.S. Sieve Series, and comprise 75 to 98% of a dental polishing agent which is an oxide or a salt selected from the group consisting of dicalcium phosphate, tricalcium phosphate, insoluble sodium metaphosphate, alumina, silica, magnesium carbonate, calcium carbonate, calcium pyrophosphate, bentonite and zirconium silicate, and mixtures thereof, 2 to 20% of ethyl cellulose and 0.1 to 1% of water insoluble coloring agent.;18. A dentifrice according to claim 15 wherein the visible functional speckles distributed through the dentifrice are agglomerates of a water insoluble powdered functional material and a combination of a water insoluble, ethanol soluble ethyl cellulose binder and a water soluble binder.;19. A dentifrice according to claim 18 which is in the form of a transparent or translucent gel, with the speckles visible therein, in which the speckles comprise from 0.1 to 10% of the dentifrice, and the water soluble binder in the speckles is PVP.;j;- 62 -;1 6 .Vj.J :.:2j;Rcoer/ED;«!;20. A dentifrice according to claim 19 which comprises 5 to 40% of glycerol, 5 to 50% of sorbitol, 5 to 30% of water, 0.1 to 5% of gelling agent, 0.5 to 5% of dental detergent, 0.5 to 2% of flavoring agent and 10 to 40%;5 of water insoluble dental polishing agent, in a continuous phase, and 1 to 3% of speckles which are of sizes in the No's. 10 to 80 range, U.S. Sieve Series, and comprise 80 to 98% of a dental polishing agent which is an oxide or a salt selected from the group consisting of dicalcium phosphate, tri-10 calcium phosphate, insoluble sodium metaphosphate, alumina, silica, magnesium carbonate, calcium carbonate, calcium pyrophosphate, bentonite and zirconium silicate, and mixtures thereof and 2 to 20% of binder comprising ethyl cellulose and PVP in a ratio within the range of 1:2 to 2:1.;21. A packaged dentifrice comprising a dispensing container, which is a deformable tube of clear or translucent synthetic organic polymeric material, containing a clear or translucent gel dentifrice comprising water, humectant,;5 gelling agent, detergent and flavor, all of which are constituents of a dental venicle of the dentifrice, and a dental polishing agent, uniformly distributed throughout the vehicle, and visible functional, opaque and impalpable speckles distributed through the dentifrice and visible through the 10 tube, which are agglomerates of a water insoluble powdered functional material and water insoluble, ethanol soluble ethyl cellulose binder.;- 63 -;"2-019 4^;22. A packaged dentifrice according to claim 21 wherein the speckles are agglomerates of a water insoluble powdered functional material, water insoluble ethanol soluble ethyl cellulose and water soluble polyvinyl pyrrolidone binders, and are of particle sizes in the No's. 30 to 60 range, U.S. Sieve Series.;23. A process for manufacturing a dentifrice containing dispersed discrete speckles therein which comprises producing a stream of a gel or paste dental composition containing a gelling agent which helps to make surfaces thereof adhesive for the speckles, which dental composition constitutes a major proportion of the dentifrice, producing a stream of speckles to be distributed throughout the dentifrice, directing said stream of speckles onto a surface of the stream of the dental composition and controlling the relative feed rates and the proportions of the streams of dental composition and the speckles' to be dispersed in the dentifrice so that when the stream of speckles contacts the stream of dental composition the speckles are insufficient to cover the dental composition- surface, so that the speckles adhere to the dental composition stream and there is produced a dentifrice containing the speckles in desired proportion distributed in it.;- 64 -;201945;24. A process according to claim 23 wjierein the stream is a ribbon of gel and constitutes all the dentifrice except for the speckles to be distributed therein, the ribbon of such gel is produced by forcing it through a suitably shaped orifice so that it is extruded from said orifice as a ribbon which flows in a direction having a horizontal component, the stream of speckles is of particle sizes within the No's. 10 to 80 sieve range, U.S. Sieve Series, said speckles are in the form of a falling curtain directed so as to fall downwardly onto the gel ribbon in such manner as to be distributed evenly over a substantial portion of the width of the flowing ribbon and adhered to said ribbon while being insufficient to cover more than half of the area of the ribbon surface presented to it, and the ribbon of gel with adherent speckles thereon is collected in a walled vessel from which it is continuously removed as additional gel containing speckles is added thereto, which vessel is under vacuum.;25. An apparatus for manufacturing a dentifrice containing dispersed speckles therein which comprises means for producing a stream of gel or paste dental composition, means for producing a stream of speckles to be' distributed throughout a dentifrice and for directing said stream onto a surface of the stream of dental composition, where such speckles will be held, and means for controlling relative feed rates and proportions of the dental composition and the speckles to be dispersed therein, so that when the stream of speckles contacts the stream of dental composition the speckles are insufficient to, cover the dental composition surface, and the speckles may adhere to the dental composition stream, and by use of such aparatus there may be produced a dentifrice containing speckles in desired proportion distributed in it. —;| PATENTOFFICE;65 ~ : 16 AUG 5?35;26. An apparatus according to claim 25 wherein the means for producing the stream of gel or paste dental composition produces a gel ribbon and includes an extruder for extruding it in a direction having a horizontal component,;5 the means for producing the stream of speckles produces a curtain of speckles and includes a helix or screw feeder and means for distributing the speckles fed thereby into a curtain of width slightly less than the width of the gel ribbon, and which apparatus includes a walled vessel above which or 10 in which the means for extruding the gel and the means for producing the curtain of speckles are located.;27. An apparatus according to claim 26 wherein the means for producing the curtain of speckles directs such speckles downwardly so that they fall in a vertical curtain onto the gel ribbon, tfre walled vessel has an outlet opening;5 at the bottom thereof, and the means for producing the gel ribbon directs it so that after the speckles contact the ribbon and are held by it, it falls vertically toward the outlet from the walled vessel and which comprises means for maintaining the walled vessel under vacuum,;10 a screw pump and a static mixer, the screw pump being;I;located in communication with an outlet from the walled vessel in which the speckled dentifrice is made so as continuously to withdraw the dentifrice from such vessel and pump it through the static mixer without disintegrating;15 or dissolving speckles thereof in the dentifrice, so that the dentifrice may be delivered to a tube filling machine without objectionable change in the appearance in the speckles.;- 66 -;2 01945;28. A process for manufacturing a dentifrice containing dispersed discrete speckles therein which comprises producing a plurality of ribbon shaped streams of a gel or paste dental composition which constitutes a major proportion of a dentifrice, producing a stream of speckles to be distributed throughout the dentifrice, directing said stream of speckles onto a surface of at least one of the streams of gel or paste dental composition and controlling the relative feed rates and the proportions of the gel or paste dental composition and the speckles to be dispersed therein so that when the stream of speckles contacts the stream of gel or paste the speckles are insufficient to cover the ribbon surface presented to the curtain, so that the speckles adhere to the gel or paste ribbon, and bringing together at least two of the plurality of streamsof the dental composition so that major surfaces thereof adhere together and sandwich the speckles between them.;29. A process according to claim 28 wherein the streams of gel or paste dental composition are a pair of ribbons of gel continuously flowing in partially opposing directions having horizontal components, and the stream of speckles is directed so as to fall downwardly onto one of the flowing gel ribbons and the amount of speckles in the falling curtain is insufficient to cover more than half of the area of the ribbon surface presented to it.;- 67 -;2;0;1;9;45;30. An apparatus for manufacturing dentifrice containing dispersed speckles therein which comprises means for producing a plurality of streams of gel or paste dental composition, means for producing a stream of speckles to be 5 distributed throughout a dentifrice and for directing said speckle stream onto a surface of a stream of gel or paste dental material, means for controlling relative feed rates and the proportions of the gel or paste dental material and the speckles to be distributed therein, so that when the curtain 10 of speckles contacts the stream of gel or paste the speckles are insufficient to cover the stream surface presented to the curtain and the speckles adhere to the gel or paste of the stream, and means for directing a separate stream of gel so;-v. _;that it adheres to the gel to which the speckles are adhered 15 and sandwiches the speckles between the streams, so that there is produced a gel or paste dentifrice containing speckles in desired proportion distributed in it.;means for producing the streams of dental composition produces a pair of ribbons of gel continuously flowing in directions having horizontal components, the means for producing a 5 stream of speckles and directing them onto the surface of a ribbon of gel directs the speckles to fall downwardly as a curtain onto such flowing gel ribbon and the means for controlling the relative feed rates and proportions of the gel and speckles controls them so that the amount of speckles 10 in the falling curtain is insufficient to cover more than half of the area of the ribbon surface presented to it.;31. An apparatus according to claim 30 wherein the;WEST-WALKER, McCABE attorneys for the applicant;68* </div>