NZ212431A

NZ212431A - Dentifrice containing siliceous polishing material and resinous poly(ethylene oxide)

Info

Publication number: NZ212431A
Application number: NZ212431A
Authority: NZ
Inventors: D K Kiozpeoplov
Original assignee: Colgate Palmolive Co
Priority date: 1981-06-26
Filing date: 1982-06-16
Publication date: 1986-01-24

Description

<div class="application article clearfix" id="description"> New Zealand Paient Spedficaiion for Paient Number £12431 2 1243 Uficfer the provisions of Reg lation 23 (I) the Specification has been ante-dated; to iv.z. PA'!'r:;-ri" <-<\ Priority Date(s): Complete Specification Filed: Class: Publication Date: .. .1986'( R.Q. Journal, No: .. „ | -j NO BRAWINGS Patents Form No. 5 Number PATENTS ACT 1953 Dated COMPLETE SPECIFICATION DENTIFRICES HWe COLGATE-PALMOLIVE COMPANY a corporation organised under the laws of the State of Delaware, United States of America of 300 Park Avenue, New York, N.Y. 10022, United States of America. do hereby declare the invention for which 1/we pray that a Patent may be granted to me/us, and the method by which it is to be performed, to be particularly described in and by the following statement: 1 - (followed toy page—1-a4 This invention relates to a dentifrice containing a siliceous polishing material and poly(ethylene oxide). Based upon prior art considerations, as disclosed in U.S. Patent 3,020,230 to Smith, wherein silica material is stated to coagulate or flocculate in the presence of resinous poly(ethylene oxide) in order to precipitate it from a liquid suspension, one skilled in the dentifrice art would not have been led to use silica materials in a dentifrice containing resinous poly(ethylene oxide). Indeed, in U.S. Patent 2,991,229 to Ivison, polishing agents or abrasives disclosed in a toothpaste containing poly(ethylene oxide) were ;'tricalcium phosphate, dicalcium phosphate and calcium carbonate and the like"; but not silica materials. It is an advantage of the present invention that a dentifrice is provided with improved stain removal which has acceptable cosmetic rheology and dentin abrasion characteristics. Further advantages will be apparent from consideration of the following disclosure. Accordingly, this invention relates to a dentifrice comprising 20-80% by.weight of a liquid humectant vehicle, 5-50% by weight of a siliceous polishing material and 0.05-5% by weight :' of a resinous poly(ethylene oxide), said dentifrice containing flocculated particles formed by said siliceous polishing agent in the presence of said poly(ethylene oxide). As mentioned above, with particular regard to a clear or opacified gel, the proportion of the siliceous -2- 18 MOV 1985 polishing agent content is in the range from 5% to 50% by weight of the dentifrice, preferably from 10% to 30% such as from 10% to 25%. One such polishing agent is a complex alkali metal aluminosilicate having a refractive index of from 1.44 to 1.47 and containing at least 70% silica, up to 10% alumina, such as about Q.l-10%, e.g. about 0.1-3%, preferably up to about 20% of moisture, such as about 0.5-10%; and up to about 10% of alkali metal oxide. Typically this material has a particle size in the range of up to about 40 microns, preferably 1 to 4 microns. The preferred mositure content is from 5% to 20% measured by ignition at 1000°C and the typical content of alkali metal oxide is from 5% to 10%. Generally, the polishing agent has a loose bulk density of up to 0.2g/cc, such as from 0.07 to 0.12g/cc. Another suitable type of polishing agent is porous amorphous silicic anhydride having an average particle size preferably below 20 microns and above 1 micron, a surface area of at least 200 m2/g, preferably at least 300 m2/g, and a 3 bulk density of at least 0.15g/cm , preferably at least 0.30g/cm^, such as a dehydrated silica hydrogel (i.e. a xerogel), preferably of the well known regular density or intermediate density type. Examples of such amorphous silicic anhydride polishing agents are "Syloid 63", "Syloid 72", and "Syloid 74" (SYLOID is a trade mark) which are described in "The Davison Family of Syloid Silicas" published by their manufacturer, Grace, Davison Chemical Company. "Santocel 100" of Monsanto (SANTOCEL is a trade mark), is also a suitable dental abrasive. "Syloid 72" has a average particle size of about 4 microns, 2 a surface area of about 340 m /g bulk density of 3 about 1.77 g/cm . For "Syloid 63" the corresponding 2 figures are about 9 microns, about 675 m /g and about 0.4 g/cm"^. A grade of "Santocel 100" has a surface area 2 3 of about 239 m /g and a bulk density of about 0.24 g/cm . These amorphous silicic anhydrides may be used singly or in mixtures. As mentioned above, the poly(ethylene oxide) comprises about 0.05-5% by weight of the dentifrice, preferably about 0.1-1.5%. In the dentifrice, the siliceous polishing agent flocculates in situ in the presence of the poly(ethylene oxide). The flocculated particles typically may agglomerate with each other and have apparent particle sizes up to about 250 microns or more, typically about 44 to 177 microns; in other words, the flocculated particles typically pass through a screen of U.S. Sieve No. 80 and are retained on a screen of U.S. Sieve No. 325. In spite of the presence of the flocculated particles the dentifrice is readily formulated to have a desirable appearance and a rheological texture without an undue "lumpy" appearance or "gritty" feel. Humectants are comprised in the liquid phase of the dentifrice, typically together with water. Typical humectants include sorbitol (as 70% aqueous solution), glycerine, maltitol, xylitol, polyethylene glycol 400 and polyethylene glycol 600. The liquid vehicle and gelling agent and other components of the dentifrice are proportioned to form a cream or gel mass of desired consistency which is extrudible from an aerosol or pump container or a collapsible tube (for example aluminum, lead or plastic). 2 7 d w " Resinous poly(ethylene oxide) has been disclosed as a dentifrice gelling or binding agent in U.S. Patent 2,991,229 to Ivison. Its presence smooths the texture of the dentifrice. The poly(ethylene oxides) employed in this invention are solid, colorless, water-soluble resins. They appear to form homogeneous systems in water in all proportions, although the relatively higher molecular weight ethylene oxide polymers merely swell on the addition of small amounts of water. On the addition of greater amounts of water, the polymers pass into solution. The water solutions are viscous, the viscosity increasing both with the concentration of the polymer in the solution and the reduced viscosity of the polymer. The ethylene oxide polymers employed in this invention show little change in melting point with increased reduced viscosity (an indication of increased molecular weight) and the melting point, as measured by change in stiffness with temperature, was found to be about 65° + 2°C throughout the range of reduced viscosities of from about 1.0 to about 10, and greater. These polymers, upon X-ray examination, disclose a crystalline structure similar to that exhibited by polyethylene. The crystallization temperature, as determined from measuring the break in the cooling curve, is about 55°C. To facilitate the understanding of the instant invention, various terms will be defined. At the outset it should be noted that the word "poly(ethylene oxide)" as used throughout the specification and claims refers to ethylene oxide polymers which have a reduced viscosity - 5 - 2 12 in acetonitrile of at least 0.5 and upwards to 75, and higher. Unless otherwise stated, by the term "reduced viscosity", as used herein, is meant a value obtained 5 by dividing the specific viscosity by the concentration of the ethylene oxide polymer in the solution, the concentration being measured in grams of polymer per 100 milliliters of solvent at a given temperature, and is regarded as a measure of molecular weight. The specific 10 viscosity is obtained by dividing the difference between the viscosity of the solution and the viscosity of the solvent by the viscosity of the solvent. The reduced viscosities herein referred to are measured at a, concentration of 0.2 gram of poly(ethylene oxide) in 15 100 milliliters of acetonitrile at 30°C (unless stated otherwise). Granular poly(ethylene oxide) results from the suspension polymerization of an agitated reaction mixture comprising ethylene oxide in contact with a polymerization 20 catalyst therefor and in the presence of an inert organic diluent, e.g., heptane, in which ehtylene oxide is soluble and the resulting poly(ethylene oxide) is insoluble. Granular poly(ethylene oxide) thus produced is obtained in a finely-divided solid particle state and resembles 25 finely-divided sand in particle size. Unlike the granular poly(ethylene oxide) resulting from the suspension polymerization process, the bulk and solution polymerization processes yield a polymer which is substantially a homogeneous mass either conforming to the shape of the reaction 30 vessel or, after driving off the organic medium, for example, - 6 - 2 1 24"^ by mechanical extrusion, e.g., Marshall Mill (under vacuum and at slightly elevated temperatures), resembles layers or sheets. This polymer subsequently can be reduced in particle size, for example, by dicing or the like. The term "granular" refers to the particle size of the ethylene oxide polymers prepared by suspension polymerization. A granular product is one which is in a free-flowing state and comprises particles averaging less than 5 mesh in size (u.s. Standard Size Sieve). When present, the poly(ethylene oxide) comprises up to about 5% by weight of the dentifrice, preferably about 0.1-1.5%. In addition to the resinous poly(ethylene oxide), a further gelling or binding agent or agents such as sodium carboxymethyl cellulose, Irish moss, Xanthan and the like may be present in amount of about 0.5-7%. Xanthan is preferred. Xanthan gum is a fermentation product prepared by action of the bacteria of the genus Xanthomonas upon carbohydrates. Four species for Xanthomonas, viz X. campetris. X. phaseoli, X. malvocearum, and X. carotae are reported in the literature to be the most efficient gum producers. Although the exact chemical structure is not determined, it is generally accepted to be a heteropolysaccharide with a molecular weight of several million. It contains D-glucose, D-mannose, and D-glucuronic acid in molar ratio of 2.8:3:2.0. The molecule contains 4.7% acetyl and about 3% pyruvate. The proposed chemical structure configuration can be found in McNeely and Kang, Industrial Gums, ed. R.L. Whistler, CH XXI, 2nd Edition, New York, 1973. The procedure for growing, isolating and purifying the xanthan gum is found in Manufacturing Chemist, - 7 - May 1960, pages 206-208 (including mention at page 208 of potential use of gums therein described for formulating toothpastes). Use of special grades of xanthan gum, such as described in U.S. Patent No. 4,263,399 are within the scope of this invention. A grade described in U.S. Patent No. 4,263,399 is a xanthan gum in which up to about 1.6% of the carboxyl groups are bound to calcium and the remaining carboxyl groups are bound to sodium, potassium, a mixture of sodium and potassium or other non-calcium cations. The total amount of gelling or binding agent in the dentifrice can be about 0.1-12% by weight. The dentifrice of the invention may contain an anionic, nonionic, cationic or amphoteric surface active agent to achieve increased prophylactic action, assist in achieving thorough and complete dispersion of the instant compositions in the oral cavity and render the instant compositions more cosmetically acceptable. A preferred surface active agent is the nonionic block copolymer containing polyoxyethylene and polyoxypropylene described in our New Zealand Patent Specification No. 200,995 Other nonionic surface active agents which may be employed include condensates of sorbitan monostearate with approximately 20 moles of ethylene oxide. Amphoteric agents include quaternized imidazole derivatives which are available under the trademark "Miranol" such as Miranol C2M. Suitable types of anionic detergents are water-soluble salts of higher fatty acid monoglyceride monosulphates, such as the sodium salt of the monosulphated monoglyceride of hydrogenated coconut oil fatty acids, higher alkyl sulphates, such as sodium lauryl sulphate, alkyl aryl sulphonates, such as sodium dodecyl benzene sulphonate, olefin sulphonates, such as sodium olefin sulphonate in which the olefin group contains 12-21 carbon atoms, higher alkyl sulphoacetates, higher fatty acid ester of 1,2-dihydroxypropane sulphonates, and the substantially saturated higher aliphatic acyl amides of lower aliphatic amino carboxylic acid compounds, such as those having 12 - 16 carbons in the fatty acid, alkyl or acyl radicals, and the like. Examples of the last mentioned amides are N-lauroyl sarcosine and the sodium, potassium, and ethanolamine salts of N-lauroyl, N-myristoyl or N-palmitoyl sarcosine, which could be substantially free from soap or similar higher fatty acid material which tends to substantially reduce the effect of these compounds. The use of these sarcosine compounds in dentifrice compositions of the present invention is particularly advantageous since these materials exhibit a prolonged and marked effect in the inhibition of acid formation in the oral cavity due to carbohydrates breakdown in addition to exerting some reduction in the solubility of tooth enamel in acid solution. Cationic surface active germicides and antibacterial compounds such as di-isobutylphenoxyethoxyethyl dimethyl benzyl ammonium chloride, benzyl dimethyl stearyl ammonium chloride, tertiary amines having one fatty alkyl group (of from 12-18 carbon atoms) and two (poly) 9 415 NOV J985 RECGfVEO 2 124 oxyethylene groups attached to the nitrogen (typically containing a total of from about 2 to 50 ethanoxy groups per molecule) and salts thereof with acids, and compounds of the structure. (CH0CH00) H -(CHoCHo0) H I / I Z I 1 x R-N-CH2CH2CH2N=^_ (CH2CH20)yH where R is a fatty alkyl group containing from about 12 to 18 carbon atoms, and x, y and z total 3 or higher, as well as salts thereof with mineral or organic acids, may also be used. It is preferred to use from about 0.05 to 5% by weight of the foregoing surface-active 10 materials in the instant dentifrice. If desired, the liquid vehicle of the visually clear dentifrice of the present invention may be a minor amount (i.e. less than about 50%) of a humectant in addition to maltitol or even a non-humectant liquid 15 vehicle component such as maltodextrin. Humectants such as indicated earlier, for instance glycerine, | sorbitol (typically 70% solution of sorbitol), poly ethylene glycol 400, polyethylene glycol 600, and the like may be used. Preferably, maltitol comprises above 20 about 50% by weight of the non-water portion of the I liquid vehicle, preferably about 65-100%. Maltitol is typically provided in about 73-85% solution and is available from suppliers including Aldrich Chemical Company, Merck and Co. Inc., Imperial Chemicals Industries, 25 Pfizer Inc., Lonza, Roquette Freres, and Hayashibara Chemical Laboratories. - 10 - * 212431 The solid portion of the vehicle is a gelling agent, such as indicated earlier, for instance the natural and synthetic gums and gum-like material, such as Irish Moss, alkali metal (e.g. sodium) carboxy-methl cellulose and xanthan as well as gum tragacanth, hydroxymethyl carboxymethyl cellulose, polyvinyl pyrrolidone, starch, guar gum, sodium alginate, hydrophilic colloidal carboxyvinyl polymers, such as those sold under the trademark Carbopol 934 and 940 and synthetic 10 inorganic silicated clays such as those sold under the trademark Laponite CP and Laponite SP. These grades of Laponite have the formula (SigMg5 ^Lig gH^ g024 ^ ^ Na+Q g. The solid portion of the vehicle is typically present in amount up to about 10% by weight 15 of the dentifrice and preferably about 0.25-5% by weight. When employed, grades of Laponite are typically used in amounts of about 1-5% by weight. The complex alkali metal aluminosilicate salt is as described above. It is typically alkaline in 20 nature, typically a sodium salt, and effectively promotes | oral hygiene. It is an amorphous powder which further has the property that when incorporated in the vehicle the particles thereof become substantially invisible. The amount of alumina in the aluminosilicate |25 is typically about 0.1-3% by weight and preferably about 1%. Desirably the refractive index of the aluminosilicate is within about 0.005 units, typically within about 0.001 of that of the liquid vehicle. As mentioned, the polishing agent typically 30 comprises about 5-50% by weight of the dentifrice formulation, preferably about 10-30% by weight. . 1 n 7 PATENT OFF -5 NOV 1985 - li REQStVEft # W <112431 ' The complex alkali metal aluminosilicate salt appears to contain interbonded silica and alumina having A1 0 Si bonds as described by Temele "Chemistry of the Surface and the Activity of Alumina-Silica Cracking Catalyst", Discussions of the Faraday Society, No. 8, Pages 270-279 (1950) and particularly at page 273, Fig. 1, curve 3, wherein the interaction between silica and aluminum ions is potentiometrically detected. Further literature describing this type of 10 complex includes Milliken et al, "The Chemical Characteristics and Structures of Cracking Catalysts", Discussion of the Faraday Society, No. 8, pages 279-290 (1950) and particularly the sentence bridging pages 284-285. These complexes clearly differ from silica gel 15 as is described by Plank et al. "Differences Between Silica and Silica-Alumina Gels I. Factors Affecting the Porous Structure of These Gels," Journal of Colloid Science, 2, pages 399-412 (1947) and Plank, "Differences Between Silica and Silica-Alumina Gels II. A Proposed Mechanism for the Gelation and Syneresis of These Gels," Journal of Colloid Science 2, pages 413-427, (1947) in which formation of the Al O Si bond is described at pages 419-422. The aluminosilicate may be described as silica containing combined alumina. 25 Organic surface-active agents may be used in the ^ compositions of this aspect of the present invention to achieve increased prophylactic action, assist in achieving thorough and complete dispersion of the instant compositions throughout the oral cavity, and render the instant compositions more cosmetically acceptable. The 20 30 - 12 - fc.Z. PATjjjjTpF'f ICE 5 NOV 1985 RECEFVED ■rintr. .i . ..... ,i 213431 ' organic surface active material may be anionic, nonionic, ampholytic, or cationic in nature as indicated above, and it is desirable to employ as the surface active agent a detersive material which imparts to the composition detersive and foaming properties. An alkali metal fluorine-providing compound may be employed in the dentifrice of the invention. The alkali metal fluorine-providing compound includes sodium fluoride, stannous fluoride, stannous chlorofluoride, potassium stannous fluoride (SnF2~KF), lithium fluoride, ammonium fluoride and complex fluorides, such as potassium fluorozirconate, sodium hexafluoro stannate and alkali metal monofluorophosphates. These compounds have a beneficial effect on the care and hygiene of the oral cavity, e.g. dimunition of enamel solubility in acid and protection of the teeth against decay, exhibit satisfactory retentions of soluble fluoride in dentifrices of the instant invention. In particular, the level of retention of monofluorophosphate ion as fluoride with the alkali metal monofluorophosphates is quite high. The fluorine-containing compound is employed in amount which provides an effective non-toxic amount of fluorine-containing ion to the dentifrice typically abbut 0.01-1% by weight preferably about 0.1% fluorine. Thus, sodium fluoride is typically employed in amount of about 0.02-2% by weight, preferably about 0.2%, and sodium monofluorophosphate, Na2P02F, in amount of about 0.1-7.6% by weight, preferably about 0.76%. The alkali metal monofluorophosphates which may be employed include sodium monofluorophosphate, lithium - 13 - 1M.Z. PATENT Off 885 -5 NOV 1985 RECEfVED 212431 monofluorophosphate, potassium monofluorophosphate and ammonium monofluorophosphate. The preferred salt is sodium monof luorophosphate, Na2P03F, which, as commercially available, may vary considerably in purity. It may be used in any suitable purity provided that any impurities do not substantially adversely affect the desired properties. In general, the purity is desirably at least about 80%. For best results, it should be at least 85%, and preferably at least 90% by weight of sodium monofluorophosphate with the balance being primarily impurities or by-products of manufacture such as sodium fluoride, water-soluble sodium phosphate salt, and the like. Expressed in another way, the sodium monofluorophosphate employed should have a total fluoride content of about 12%, preferably about 12.7%; a content of not more than 1.5%, preferably not more than 1.2% of free sodium fluoride; and a sodium monofluorophosphate content of at least 12%, preferably at least 12.1%, all calculated as fluorine. Other monofluorophosphate salts which may be used in the instant invention include monofluoropoly-phosphates such as Na4P3OgF, K^P^O^F, (NH4)4P30gF, Na3KP309F, (NH4)3NaP3OgF and Li4P3OgF. may be employed in formulating a flavour for the dentifrice compositions of the present invention. Examples of suitable flavouring constituents include the flavouring oils, e.g., oils of spearmint, peppermint, wintergreen, sassafras, clove, sage, eucalyptus, majoram, cinnamon, lemon and orange, as well as methylsalicylate. Suitable sweetening agents include, sucrose, lactose, maltose, Any suitable flavouring or sweetening materials 14 3 " # sorbitol, sodium cyclamate, perillartine and saccharine. Suitably, flavour and sweetening agents may together comprise from about 0.01% to 5% or more of the compositions of the instant invention. Chloroform may also be used. Sweetening agents are less necessary when no anionic surface active agent is present, since anionic surface active agents contribute slight bitterness to the dentifrice. Antibacterial agents may be employed in the described dentifrice in an amount of about 0.01 to 5% by weight. Typical antibacterial agents include: 1 5 N -(4-chlorobenzyl)-N -(2,4-dichlorobenzyl)biguanide; P-chlorophenyl biguanide; 4-chlorobenzhydryl biguanide; 4-chlorobenzhydrylguanylurea; 5 15 N-3-lauroxypropyl-N -p-chlorobenzylbiguanide; 1,6-di-p-chlorophenylbiguanidohexane; 1,6-bis(2-ethylhexylbiguanido)hexane; 1-(1auryIdimethylammonium)-8-(p-chlorobenzyldimethyl-ammonium)octane dichloride; 20 5,6-dichloro-2-guanidinobenzimidazole; ^ N1-p-chlorophenyl-N^-laurylbiguanide; 5-amino-l,3-bis(2-ethylhexyl)-5-methylhexahydropyrimidine; and their non-toxic acid addition salts. Various other materials may be incorporated in the preparation of this invention. Examples thereof are colouring or whitening agents or dyestuffs, preservatives, silicones, chlorophyll compounds, ammoniated materials such as urea, diammoniumphosphate and mixtures thereof, and other constituents. The adjuvants are incorporated in the instant 30 compositions in amounts which do not substantially adversely - 15 - fe } ' u ^ affect the properties and characteristics desired and are selected and used in proper amounts depending upon the particular type of preparation involved. Synthetic finely divided pyrogenic silica such as those sold under the trademarks Cab-O-Sil M-5, Syloid 244, Syloid 266 and Aerosil D-200 may also be employed in amounts of about 1-5% by weight to promote thickening or gelling of the described dentifrice. The dentifrices should have a Ph practicable for use. A moderately acid to alkaline pH is preferred. The following specific examples are further illustrative of the nature of the dentifrices present invention, although it is understood that the invention is not limited thereto. All amounts are by weight unless otherwise indicated. The following opacified gel dentifrices are prepared. EXAMPLES 1-2 1 2 Glycerine 10 .0 15.0 10.0 Maltitol 15.0 Sodium aluminosilicate (silica combined with about 1% combined alumina) Zeo 49B (Huber) 18 .0 18.0 3.0 Pluronic 108 block copolymer Sodium lauryl sulfate Xanthan Polyox WSR 301 Sodium monofluorophosphate Titanium dioxide Low Menthol flavour Peppermint oil flavour Sodium saccharin Colour solution (l|) Water Q.S. to 100 Q.S. to 100 0 .05 0.5 0.2 0. 76 0.4 1.0 2.0 0.2 0.05 2.0 0.2 0 . 76 0.4 0.5 16 The dentifrice of Example 1 with sodium lauryl sulfate has desirable foam character. The dentifrice of Example 2 also has very good stable full-bodied foam character even though no anionic surface active agent is employed. The foam remains throughout the oral cavity, with desirable mouth feel, when the dentifrice is brushed onto the teeth. Moreover, it has no bitter note even though low menthol flavour is present and no sweetener is added. The dentifrices have fine smooth texture and appearance, effectively remove stain and have acceptable dentin abrasion character. They contain flocculated particles of sodium aluminosilicate. Similar desirable results are obtained when xanthan of Example 2 is replaced with the low-calcium xanthan of Example 1 of U.S. Patent 4,263,399. Similar foam and feel is attained when other block copolymers of polyoxyethylene and polyoxypropylene replace Pluronic F-108, particularly Pluronic F 87v Pplyox WSR-301 is available from Union Carbide Corp. as granules of water soluble poly(ethylene oxide) resin having a molecular weight of about 4,000.000 and a Brookfield viscosity of 1650-3850 cps. (25°C, spindle 1, speed 2 rpm) when in water at 1% by weight. Likewise, similar foam and feel is attained when other water-soluble poly(ethylene oxide) resins available from Union Carbide Corp. as Polyox WSR-N-10, WSR-N-80, WSR-N-750, WSR-N-3000, WSR-200 and WSR-1105 replace Polyox WSR-301, in different concentrations. The silica with combined alumina indicated in Examples is obtained from J.M. Huber, Corp. of Havre de Grace, Maryland, as Zeo 49 (A or B). The following clear gel (3 and 4) and opacified gel (5 and 6) dentifrices are prepared: - 17 - 2 1243 1 EXAMPLES 3-6 3 4 5 6 Glycerine 10 .0 — 10.0 — Sorbitol 16.0 — 15.0 — Maltitol (Active) 16.0 35-.-0 15.0 30.0 Sodium aluminosilicate (silica with combined alumina) 22.0 18.0 18.0 18.0 Pluronic F-108 3.0 3.0 5.0 — Pluronic F-87 — — — 3.0 Xanthan 1.5 2 .0 2.0 2.0 Polyox WSR-301 0.2 0.2 0.2 0.2 Sodium monofluorophosphate 0.76 0. 76 0 . 76 0.76 Titanium dioxide — — 0.4 0.4 Low Menthol Flavour 0.5 0.5 0.5 0.5 Colour solution (1%) Water 0.05 Q.S. to 100 0.05 Q.S. to 100 0 .05 Q.S. to 100 0.05 Q.S. to 100 The dentifrices of: Examples 3 and 4 are clear and those of Examples 5 and 6 are opacified. They have smooth texture. All four have very good stable full-bodied foam, with that of the dentifrice of Example 5 being more full then with the dentifrices of Examples 3 and 4. A higher amount of foan occurs with the dentifrices of Example 6. All foams provide desirable mouth feel throughout the entire oral cavity during tooth brushing. There are no bitter notes. The dentifrices effectively remove stain and have acceptible dentin abrasion. They contain flocculated particles of sodium aluminosilicate. The following dentifrices are prepared: - 18 - EXAMPLES 7-11 7 8 9 10 11 Maltitol (ACTIVE) 30 .0 30. 0 30 .0 30. 0 30 . 0 Sodium aluminosilicate (silica with combined alumina) 12 .0 12 . 0 12 .0 18. 0 15 . 0 Calcined alumina .1 5 .0 5 . 0 5 .0 5 . 0 2 . 0 Pluronic F-108 3 .0 3 . 0 3 .0 3. 0 3 . 0 Xanthan 2 .0 2 . 0 2 .0 ; ' ,1. 7 2 . 0 Polyox WSR-301 WSR-1105 WSR-750 0 .2 0. 2 1 .0 0 . 2 0 . 2 Sodium monofluorophosphate 0 . 76 0. 76 0 . 76 0 . 76 0. 7( Titanium dioxide 0 .4 0 . 4 0 .4 0. 4 0. 4 Low Menthol flavour 0 .5 0 . 5 0 .5 0. 5 0. 5 Q.S. to Q.S. to Q.S. to Q.S. to Q.S. to 100 100 100 100 100 The dentifrices of Examples 7-11 provide high cleaning effectiveness and have good, stable, full-bodied foam. They have smooth texture, with the dentifrices of Examples 7, 10 and 11 containing Polyox WSR-301 having the best texture. All foam to provide desirable mouth feel throughout the entire oral cavity during toothbrushing. Thereeare no bitter notes. They effectively remove stain and have acceptable dentin abrasion. They contain flocculated particles of sodium aluminosilicate. EXAMPLES 12-13 The following opacified gel dentifrices are prepared: - 19 - ("S c ■» -i 1 -d y. o 1 Maltitol (75% solution) 40.00 40.00 Sodium aluminosilicate (silica containing about 1% combined alumina - Zeo 49B-Huber 18.00 18.00 Pluronic F 108 Block Copolymer 3.00 3.00 Xanthan 1.70 1.70 Polyox WSR-301 (Union Carbide) 0.20 Titanium dioxide 0.40 0.40 Flavour 0.50 0.50 Sodium saccharin 0.20 0.20 Deionized water Q.S. to 100 Q.S. to 100 Both dentifrices provide stable full-bodied foam with good mouth feel; the mouth feel of dentifrice 12 being particularly satisfactory. When compared for ability to remove dental stain and in dentin abrasion, the dentifrice of Example 12 containing the Polyox material removes more stain with less dentin abrasion than the dentifrice of Example 13, without Polyox material. In the dentifrice of Example 13, flocculated particles of sodium aluminosilicate form in situ. The results are as follows: PERCENT RADIOACTIVE DENTIFRICE STAIN REMOVAL DENTIN ABRASION 12 35 14 13 22 39 In a stain removal test, sections of human dental enamel are etched with 0.1N HC1 for 2 minutes, rinsed with water, then wet with a dilute solution of stannous fluoride, wiped dry, and finally exposed to a stream of hydrogen sulfide gas which results in the deposition of a brown deposit of stannous sulfide. The amount of stain on the surface is measured with a Gardner Automatic Colour Difference meter. The surface is then brushed with a mechanical brushing machine for 500 reciprocal strokes with a slurry of a dentifrice and the residual stain measured with the meter. Finally, the stain which remains is completely removed with dental pumice and the reflectance of this surface is read. The ability of a dentifrice to remove the stain is expressed by the following equation. Percent Stain removed= (Rd criri . , - Rd. ... , ) 100 500 strokes initial Rd . - Rd. ... , pumiced initial where R(^initial, 500 strokes, and ^pumiced are respectively the reflectance values measured on the initially stained surfaces, after brushing for 500 reciprocal strokes and after removing the residual stain by pumicing. The RDA values are obtained by a procedure based on a radioactive technique described in the literature; Stookey, C.K. and Muhler, J.C., J. Dental Research 47 524 - 538 (1968) . EXAMPLES 14-15 The following dentifrices are prepared: - 21 - 2 1243 PARTS 14 15 Maltitol (80%) 59% 59 . 0 Deionized water 10. 74 10 . 74 Sodium monofluorophosphate 0.76 0 . 76 Sodium saccharine 0.25 0 . 25 Sodium carboxymethyl cellulose 0.35 0 . 35 Polyethylene glycol (Carbowax 600) 3.0 3 . 0 Silica xerogel (Syloid 74) 18.0 - Sodium aluminosilicate (silica containing about 1% combined alumina - Zeo 49B-Huber) 18. 0 Sodium lauryl sulfate 1.2 1. 2 Flavour 1.2 1. 2 The refractive index of Syloid 74 in the dentifrice of Example 14 and Zeo 49B in the dentifrice of Example 15 is within about 0.005 unit of that of the liquid vehicle of each dentifrice. Each of the dentifrices is initially shiny and clear. However, after one week at room temperature, the dentifrice of Example 14, containing silica xerogel, becomes dull in appearance and upon being left exposed to air becomes opaque white-like colour and quite hear. Under these same conditions, the dentifrice of Example 15 remains shiny and clear and continues to have desirable flow characteristics. EXAMPLES 16-18 The following visually clear dentifrices are prepared in which the refractive index of the polishing agent is within 0.005 unit of that of the liquid vehicle. - 22 - </div>

Claims

<div class="application article clearfix printTableText" id="claims"> 1 <=r? \\ PARTS 16 Maltitol (73%) 62.0 Maltitol (80%) Deionized water 7.24 Sodium monofluorophosphate 0.76 Sodium saccharin 0.25 Sodium benzoate 0.50 Sodium carboxymethyl cellulose 0.35 Xanthan Polyethylene glycol 3.00 (Carbowax 600) Sodium aluminosilicate (silica containing about 1% combined alumina-Zeo 49A in Example 21 and Zeo 49B in Examples 22 and 23 (Huber) 18.00 Silica thickener (Syloid 244) 5.50 Sodium lauryl sulfate 1.20 Flavour 1.20 17 60 .0 16.6 0 . 76 0.24 0.4 18 48.0 22 .6 0 . 76 0.24 1.4 20.00 20.00 1.20 1.20 0.80 0.80 Although this invention has been described with regard to illustrative examples, it will be apparent to one skilled in the art that various modifications may be made thereto which fall within its scope as defined in the appended claims. - 23 - WHAT WE CLAIM IS:

1. A dentifrice comprising 20-80% by weight of a liquid humactant vehicle, 5-50% by weight of a siliceous polishing material and 0.05-5% by weight of a resinous poly.(ethylene oxide), said dentifrice containing flocculated particles formed by said siliceous polishing material in the presence of said poly(ethylene oxide).

2. The dentifrice claimed in claim 1 wherein said resinous poly(ethylene oxide) has a reduced viscosity of at least 0.5 as measured at a concentration of 0.2 gram of said poly(ethylene oxide) in 100 milliliters of acetonitrile at 30°C.

3. The dentifrice claimed in claim 2 wherein said resinous poly(ethylene oxide) is present in amount of 0.1-1.5% by weight.

4. The dentifrice claimed in any one of claims 1 to 3 wherein said siliceous polishing material is a complex alkali metal aluminosilicate having a refractive index of from 1.44 to 1.47.

5. The dentifrice claimed in claim 4 wherein said alkali metal aluminosilicate is sodium aluminosilicate wherein silica is combined with 0.1-3% alumina.

6. The dentifrice claimed in any one of the preceding claims wherein said flooculated particles have an apparent particle size of 44 to 177 microns. - 24 - RECEIVED 0s £P <^N 2 [? ■/£ The dentifrice claimed in any one of the preceding laims wherein maltitol is present as humectant. WEST-WALKER, McCABE per: ATTCTRfrtYS FOR THE APPLICANT - 25 - </div>