FI71226C - SLIPEEMNEN OCH COMPOSITION I TANDPASTA SOM HAR GOD KOMPABILITET MED FLUORIDER - Google Patents

Description

ΓΓ £ 5 = 71 ANNOUNCEMENT 7100 ^ LBJ (11) UTLÄGGNINGSSKRIFT f 'λ 2. 6 C (45) Patent belt tty (51) Kv.ik. * / Int.ci. «A 61 K 7/18, C 09 C 1/30, C 01 B 33/18 FINLAND —FINLAND (21) Patent application - Patentansoiening 78-8θ7 (22) Date of application —- Ansökningsdag 1 A.03.78 (23) Starting date - Giltighetsdag 1 A. 03.78 (41) Publication - Blivit offentlig 2 ] 06 79

Patent · and National Board of Registration ^ Date of display and publication— nq nq n, ·

Patent and registration authorities Ansökan utiagd och utl.skriften publicerad uy.uy.oo (86) Kv. application - Int. ansökan

(32) (33) (31) Privilege claimed - Begärd priority 20.12.77 USA (US) 86238A

(71) JM Huber Corporation, Navesink & River Road, Locust, New Jersey, USA (72) Satish Kumar Wason, Churchville, Maryland, USA (7A) Oy Koister Ab (5A) Toothpaste abrasives and - The present invention relates to a dentifrice with a fluoride derivative. improved abrasives. In particular, the present invention relates to novel alkaline earth metal treated and doped silica abrasives suitable for use in therapeutic toothpaste compositions containing both soluble fluoride salts as enamel solubilizers and soluble phosphate salts as a dentifrice. The invention further relates to methods for preparing these improved doped p.1- "" dioxide abrasives i. And toothpastes containing improved abrasives, including forms of toothpaste comprising both enamels reducing enamel solubility (i.e., fluorine di <1) and Such toothpaste compositions11a have both good fluoride compatibility and good cleaning ability.

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The abrasive of the compositions intended for use in the oral cavity has the function of removing various deposits from the surface of the teeth, e.g. the film covering them. This is firmly attached and often contains brown or yellow pigments. Thus, the appearance of the teeth is unpleasant. An effective toothpaste abrasive must maximally remove this film without rubbing too much hard tissue on the teeth. Dental researchers are constantly working to develop toothpaste abrasives that clean adequately without rubbing and damaging the tissues of the mouth too much.

In addition to abrasives, treating toothpastes typically contain fluoride ion sources. It is well known that by applying solutions containing fluoride ions externally to the surface of tooth enamel, the incidence of tooth decay is reduced. In particular, a solution with a pH of about 4-8 is believed to reduce the acid solubility of the enamel. Mica thus treated with fluoride is more resistant to the formation of tooth decay. Thus, therapeutic toothpaste compositions have been formulated which form fluoride ions in brushing solutions formed in the oral cavity during use.

It has been hypothesized that the effectiveness of the fluoride treatment to prevent melt dissolution and / or tooth decay depends on the amount of fluoride ion available to the mica in question. Thus, of course, it is desirable to formulate toothpaste compositions that provide maximum availability of fluoride ions in brushing solutions composed of the compositions. However, it has not been possible to use such anti-tooth decay fluoride ions in home toothpastes to provide a theoretical maximum amount of soluble fluoride because the fluoride ion tends to be inactivated and thus not available in enamel. Thus, toothpastes lose the ability to provide the theoretical maximum amount of soluble fluoride during storage (with increasing rate with temperature). In the present invention, the "soluble fluoride" content of each of said toothpaste compositions means the concentration of fluoride ion in ppm (parts per million) of a 1: 3 part by weight suspension of toothpaste and water in a centrifuged liquid (1: 3 = toothpaste: water).

Fluoride ion sources and toothpaste impurities as well as toothpaste components such as abrasives, buffers, etc. tend to interact with 3,71226. Such an interaction reduces the ability of the fluoride source to provide "soluble fluoride" during use. The tendency of toothpaste compositions to maintain their level of soluble fluorine after storage is hereinafter referred to as "fluoride compatibility of toothpaste". Thus, the compatibility of a toothpaste with a given toothpaste composition is the percentage of the theoretical maximum amount of fluoride source that is actually determined as soluble fluoride after temporary storage at a specified temperature (e.g., a week at 49 ° C). Similarly, the tendency of such a dentifrice, such as an abrasive, to interact with a fluoride source, with the determined "soluble fluoride" level decreasing from the theoretical maximum of the fluoride source (especially in the presence of toothpaste permeating agents described in detail below), is referred to as "abrasive". Test methods for determining "fluoride compatibility of toothpaste" and "abrasive compatibility" are described in detail below.

The toothpaste component which may present particular difficulties in formulating fluoride toothpastes is the precipitated silica abrasive component. Precipitated silica abrasives are desirable in toothpastes because they consume the desired amount of dental bone. Some prior precipitated silica abrasives in the art are generally compatible with soluble fluorine sources, but their abrasion efficiency is too low for effective cleaning. Some prior art precipitated silica abrasives have acceptable cleaning performance, but have low fluoride compatibility with the abrasive as determined by the method described below. It is likely that no prior art doped silica abrasive will achieve both good "abrasive fluoride compatibility" and acceptable cleaning performance (as indicated by the constant radioactivity values for dental abrasion). Thus, there is a clear need to formulate precipitated silica abrasives that have both good "abrasive fluoride compatibility" and acceptable cleaning performance. Thus, it is an object of the present invention to provide precipitated silica abrasives having good "abrasive fluoride compatibility" and acceptable cleaning performance.

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Another dentifrice component that may be particularly destructive to soluble fluoride in certain toothpaste compositions is soluble phosphate. Phosphate salts soluble in toothpaste facilitate the penetration of fluoride ions through the membrane covering the teeth. Therefore, it is preferred to add soluble phosphate salts to fluoride toothpaste compositions. But, especially with silica abrasives for toothpaste, soluble transmitters tend to promote the loss of soluble fluoride in toothpastes containing these materials, and thus the fluoride compatibility values of toothpaste in toothpastes are low. Thus, there is a clear need to formulate precipitated silica abrasives that achieve high fluoride compatibility of toothpaste when used in toothpastes containing soluble phosphate salts as membrane penetrants.

Thus, there is a further need for fluoride toothpastes which may contain precipitated silica abrasives and soluble phosphate salts. Accordingly, it is an object of the present invention to provide fluoride toothpaste compositions which contain soluble phosphate salts and precipitated silica abrasives and nevertheless retain relatively high concentrations of soluble fluoride even after storage.

It has surprisingly been found that the above objects can be realized by means of the present invention, which provides a novel doped silica abrasive treated with an alkaline earth metal material, in particular calcium. Using the dentifrice powders in question, fluoride toothpastes - especially embodiments containing soluble phosphate salts - can be prepared which have good fluoride compatibility of toothpaste and excellent cleaning performance.

It is, of course, well known that therapeutic toothpaste compositions contain calcium phosphate ingredients as abrasives, but these amounts are high, as described and explained above, e.g., in U.S. Patent 3,624,199, issued November 30, 1971 to Norfleet et al. and 3,864,471, issued February 4, 1975 to Mills et al. Toothpaste compositions containing small amounts of alkaline earth metal ions, such as calcium ions, are also known in the art, and compositions of this type are described in U.S. Patent 3,991,177, published November 5, 1972 to Vidra et al. This patent discloses toothpaste compositions comprising a dextranase enzyme stabilizer activator which is a salt such as calcium chloride in an amount of 0.001 to 0.3% by weight. This composition may also contain therapeutic fluoride and the abrasive is calcium carbonate.

Previous publications in the art dealing with toothpaste compositions containing alkaline earth metal compounds or ions include U.S. Patents 3,995,356, issued June 25, 1963 to Mess, 3,122,483, published February 25, 1964 to Rosenthal, 3,659,221, published June 13, 1972. Hacelle, 3 782 4 46, published 1.1.1919; i Wal ter, 3 84? 168, published on 15.1974 in Colodneyilo and 3 689 53 7, published on 5.9.1972 for Kuder. However, none of these prior patents in the art have disclosed therapeutic marmoset compositions comprising, as an abrasive, a picene molecule precipitated with an oxide containing about 13 to 332 ppm of the alkaline earth metal ion described above.

The present invention provides a novel propellant for toothpaste compositions which, in its broadest embodiment, contain precipitated silica prepared from fresh aqueous alkali tallow by acidifying and treating the resulting product with alkaline earth ions. Such a precipitate (the preferred abrasives contain about 10-30 U parts per million of alkaline earth metal ions and their characteristic values are an RDA value t (Radioact Ivo Dentin Abrasion, a value obtained by the method for determining the radioactivity of human bone wear) of at least 40, an oil absorption value of about 79-95 cm '/ 100 n, packing density approx. 0.24-0.55 g / ml, annealing loss approx. 4-6% and BET surface area approx. 100 -250 m ^ / g and average particle size approx. 5-15 The invention also relates to a process for the preparation of these novel abrasives, in which low molecular weight doped silica is generally prepared by acidifying certain fresh water sodium silicate solutions with mineral acid and then treating the resulting wet cake with the required amount of alkaline earth metal ions.

In addition, the present invention relates to fluoride-containing toothpaste compositions having a minimal loss of soluble fluoride during storage at normal temperatures and when an excellent pulp is reached. Such dentifrices include "amorphous" amorphous doped silica abrasives, a source of fluoride ions, a binder, a wetting agent and water according to the present invention. The pH of such toothpaste compositions is about 4.0 to 8.0 slurried in water in a weight ratio of water to composition of 3: 1.

The amorphous, precipitated silica abrasives of the present invention comprise about 6-35% by weight of the toothpaste compositions.

The fluoride ion source constitutes about 0.01 to 3.0% by weight of the toothpaste compositions and as such may be any water-soluble substance that forms fluoride ions in aqueous solution.

The binder constitutes about 0.2 to 2% of the toothpaste compositions.

The wetting agent constitutes about 5-55% by weight of the toothpaste composition. The water of these toothpastes constitutes about 15-80% by weight of the composition.

The present invention relates to novel precipitated silica abrasives for dentifrices, to processes for their preparation and to their incorporation into toothpastes in order to obtain compositions having excellent fluoride compatibility and abrasion values of toothpaste. In addition, these toothpaste compositions contain a substantially water-soluble fluoride ion source, a binder, a certain amount of wetting agents, and water. All of these components, optional ingredients, use of the compositions, and their preparation are described in detail below.

The present invention relates to low molecular weight, precipitated silica materials which can be used as dentifrices. In addition, these abrasives contain about 10-300 parts per million, preferably 10-100 parts per million of alkaline earth metal, preferably calcium, of the amount of dry matter that can be recovered. This dentifrice is further characterized in that its abrasive has a fluoride compatibility of at least 90%, an RDA of at least 40, preferably about 70-120, an annealing loss (hereinafter "HH") of 4-6%, a packing density of about 0.24 to 0 .55 g / ml, oil absorption value n.

70-95 cm 3/100 g, BET surface area about 100-250 m 2 / g and average particle size 5-15 microns. When combined with toothpaste, these toothpastes achieve high fluoride compatibility and excellent cleaning performance. The definition of low molecular weight silica materials is given in the aforementioned U.S. Patent 3,893,840.

7,71226 The dentifrices of the present invention are precipitated silicas prepared by known methods. These are described, for example, in earlier U.S. Patents 3,893,840, issued June 8, 1975 (Wason), 3,988,162, published January 26, 1976 (Wason), and U.S. Patent Application No. 0,703-96, issued July 8, 1976. All of these patents and the patent application are incorporated herein by reference. Abrasives prepared by such methods are then treated with alkaline earth metal ions as described above. Generally, in the production of silicas, the alkali metal vcs .1 Liu <'S is acidified with mineral acid to precipitate silica. The acid is added to kill to pH, the silica precipitate formed is isolated, e.g. by filtration, washed to remove by-products such as early metal sulfate and a moist cake is obtained. The resulting moist cake is soaked in its own water or using additional water and then treated with the required amount of alkaline earth metal ions in the form of a soluble salt to obtain the abrasives of this invention.

The abrasive products of the present patent application must be distinguished from the precipitated alkaline earth metal ion-treated silica compositions discussed in earlier U.S. Patent Application No. 723,345, filed September 15, 1976, and its continua-tion-in-part application No. 826,901. made 2 4.8.19 7 7. The alkaline earth metal treated silicas disclosed in U.S. Patent Application Serial No. 826,901 are abrasives that can be incorporated into toothpaste compositions to protect uncoated toothpaste aluminum tubes from corrosion. The corrosion-protected precipitated silicas described in U.S. Patent Application No. 826,901 are prepared by the so-called by the sulphate liquid method. In this method, an electrolyte such as an alkali metal sulfate and an alkali metal silicate liquid are mixed with a mineral acid during acidification. The method was not disclosed, e.g., in U.S. Patents 3,960,586 and 3,928,541. When U.S. Patent No. 826,901 can be described as precipitated silicas thoroughly mixed with alkaline earth metal ions in the same amount as in the present invention, the present invention the characteristic values differ from those of the silicas obtained by the sulphate-liquid method. When used in certain fluoride-containing dentures, the sulfate liquid pixel ingredients do not provide the excellent fluoride compatibility values of the present invention. The excellent fluoride compatibility values of the dentifrices of the present invention are achieved only with silicas prepared by the so-called by the freshwater alkali metal silicate method.

The silica abrasives of the present invention are alkaline earth metal treated, precipitated silicas prepared from fresh water silicate solutions. This method does not use an electrolyte such as sodium sulfate to prepare crude precipitated silica. In addition, it has been found that the amount of alkaline earth metal orors closely related to the silica formed in the products of the present invention must be in a particularly narrow range in order to achieve the fluoride compatibility necessary in the present invention. Thus, the abrasive articles of the present invention have a fluoride compatibility of at least 90 L, but previously the abrasive compatibility of U.S. Patent Application No. 826,901 is generally 89% or less as determined by the fluoride compatibility tests of toothpaste described in this patent application.

It has been theorized that the improved fluoride compatibility of the dentifrices to be treated is based on the manner in which the silanol groups are attached to the surface of the silica product. Thus, it is believed that on the surface of the freshwater silicate-derived silica of the present invention, silanol groups are better available than in the sulfate-liquid silicate-derived silica disclosed in U.S. Patent Application No. 826,901, filed August 24, 1977. In addition, due to the silanol groups, the surface acidity of the freshwater silicas is higher than the corresponding acidity of the silicas obtained in the sulfate seed process. Because the silanol groups of the two materials are different, the internal surface acidity does not react well when treating sulfate liquid products with calcium to achieve fluoride compatibility. The products of U.S. Patent No. 826,901 also have higher consumption values than the silicas of this patent application. Accordingly, the present abrasives must be separated from the alkaline earth metal-treated silicas disclosed in U.S. Patent Application No. 826,901.

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Preferably, the precipitated silica abrasives to be treated are prepared by charging an aqueous solution of an alkali metal silicate solution, preferably a sodium silicate solution, to the reactor for acidification. The aqueous sodium silicate solution is a fresh aqueous solution having a sodium silicate content of about 10-17% by weight and preferably 12.5-15.5% by weight and a sodium silicate composition of Na 2 .2.6 SiO 2 for best results. The temperature of the aqueous sodium silicate solution is then raised to about 50-95 ° C and, with constant stirring, the solution is acidified with an aqueous solution of mineral acid having a concentration of approx.

10-20% by weight at an almost constant pH of about 8.5-10.5. Preferably, the mineral acid is sulfuric acid because it gives the best results, but it is known in the art (see U.S. Patents 3,988,152 and 3,893,340 and U.S. Patent Application No. 703,495, filed July 8, 1976) that other acidifying agents may also be used. such as nitric acid, phosphoric acid, hydrochloric acid, carbonic acid, etc. In this regard, the disclosures of these prior patents and U.S. Application 7C3,496 are specifically incorporated herein by reference because they disclose a process for preparing the present silicas.

In a more preferred embodiment, only a part of the alkali metal silicate solution is charged to the reactor, the temperature being raised. with stirring and the sulfuric acid and the remainder of the alkali metal silicate solution are added simultaneously to the silicate solution initially at the reaction temperature. Initially, about 8-12% by weight of metal silicate is preferably charged to the reactor. The remainder and sulfuric acid are then added. The addition time of alkali metal silicate and sulfuric acid to the alkali metal silicate in the reactor can be determined in advance and generally depends on the volume of the reactor and the difficulties involved in controlling the temperature and agitation. After the addition of the alkali metal silicate solution is complete, the addition of the acidifying agent is continued until the pH of the reaction suspension drops below n.

5.0 and preferably in the range of about 4.6-5.0. A suspension of precipitated silica in the reaction medium is formed.

When a pH of less than 6.0 is reached, the suspension is digested for a specified time by heating at a temperature 10-30 ° C higher than the reaction temperature, and the reaction pH is adjusted as needed. The resulting suspension is then filtered and washed with additional water to remove reaction by-products such as sodium sulfate from the silica product. The formed filter cake has a moisture content of about 60-66% and consists of low molecular weight material. Up to this point, the reaction described above is generally the same as that described in U.S. Patents 3,893,840 and 3,988,162 described above and in U.S. Application 703,496 for the preparation of silica from freshwater alkali metal silicate.

In the process of the present invention, in the wet silica cake filtration and washing step, the material is treated with alkaline earth metal ions to obtain novel abrasion products of the present invention. According to the method of the present invention, the washed and moist filter cake is reslurried in its own water or by adding fresh water at ambient temperature with stirring. When stirring the suspension, a sufficient amount of alkaline earth metal ions, preferably calcium ions, are treated in the form of a salt having a solubility such that the amount of alkaline earth metal ions is about 10 to 30 parts per million, i.e. 0.001 to 0.03% by weight of the dry silica recoverable. These alkaline earth metal ions are inextricably linked to silica.

The alkaline earth metal ion added at this point is preferably a calcium ion because it is readily available, inexpensive, and easy to incorporate into silica. At this stage, the calcium ions can be incorporated into the silica in a sufficiently soluble form (ie the water solubility must be at least 0.07 g / 100 ml of water at 20 ° C). Examples are solutions of calcium nitrate, calcium oxide, calcium hydroxide and calcium chloride. Lime and calcium hydroxide are recommended. Solutions of organic salts such as calcium acetate and calcium formate can also be used. The corresponding strontium and magnesium salts of the alkaline earth group can also be used. Food salts must be used.

After the alkaline earth metal ion treatment, the cake suspension is stirred vigorously for 10-20, preferably 15 minutes to obtain an effective amount of alkaline earth metal to treat the surface of the silica abrasive. The product formed is then dried. Preferably, the drying takes place in a spray dryer at an inlet temperature of 483 ° C and an outlet temperature of 122 ° C in a manner known in the art and is then ground to the desired particle size.

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Toothpastes The present invention also provides therapeutic toothpastes containing novel precipitated silica abrasives. In addition to the abrasives to be treated, the toothpaste compositions of the present invention further contain certain amounts of a water-soluble fluoride ion source, a binder, a wetting agent and water. All of these additional toothpaste components and optional toothpaste components are described in detail below.

A. Abrasive

As mentioned above, the precipitated silica abrasives in question are particularly suitable for incorporation into fluoride-containing therapeutic toothpaste compositions. Therapeutic toothpastes containing such abrasives achieve satisfactory tooth cleaning performance and also have excellent abrasive fluoride compatibility properties. The toothpaste compositions to be treated contain substantially about 6-35%, preferably about 10-20% by weight of the precipitated silica abrasives to be treated.

B. Fluoride ion source

In addition, the therapeutic toothpaste compositions to be treated contain from about 0.01 to 3, preferably from about 0.1 to 1.0% by weight of a water-soluble, fluorine-containing substance which forms fluoride ions in aqueous solutions. Such fluoride ions are associated with tooth enamel, thus reducing its solubility in acid. Adding fluoride ions to tooth enamel protects teeth from decay.

A wide variety of fluoride ion generating materials can be used as sources of soluble fluoride in the present compositions. Examples of suitable fluoride ion generating materials can be found as follows: Briner et al., U.S. Patent 3,535,421, issued October 20, 1970, and Widder et al., U.S. Patent 3,678,154, issued July 18, 1972. Both patents are incorporated herein by reference. Preferred fluoride ion sources useful herein include sodium fluoride (NaF), stannofluoride (SnF 2), potassium fluoride (KF), potassium stannofluoride (SnF 2 -KF), indium fluoride 12 71 226 (InFg), zinc fluoride (7 ^ 2) , ammonium fluoride (NH 4 F) and stannous chlorofluoride (SnClF). Sodium fluoride and stannofluoride and mixtures thereof are particularly preferred.

Preferably, the toothpaste compositions to be treated form about 50-500 ppm, especially about 100-400 ppm of fluoride ions in aqueous solutions that come into contact with tooth surfaces when using the toothpastes of the present invention in the mouth. As described in detail below, such solutions are mimicked by preparing suspensions of water and toothpaste of the toothpaste compositions to be treated in a weight ratio of 3: 1 and then centrifuging these suspensions to obtain an aqueous solution on top of the precipitate. The fluoride ion concentration of such a supernatant solution is considered to be "soluble fluoride" of the flucrid toothpaste composition. as a measure.

C. Binder

The binder is used primarily to prevent the separation of the liquid and solid phases of the toothpaste compositions in question. Such binders are well known in the toothpaste industry. The most commonly used binders are seaweed colloids such as carrageenan (Viscarin®) and cellulose derivatives such as sodium carboxymethylcellulose and hydroxyethylcellulose. Another type of binders useful herein are gums such as 1) vegetable gums, e.g., guar gum, and 2) fermentation products, e.g., xanthan gum. In general, the binder component constitutes about 0.1 to 5%, preferably 0.2 to 2% by weight of the toothpaste compositions to be treated. Because microorganisms and yeasts degrade the natural and synthetic aqueous dispersions of water binders, the treated toothpastes may optionally contain a relatively small amount of preservative. Examples of preservatives typically used are esters of parahydroxyl benzoates.

Toothpaste binders are described in more detail in Hager et al., U.S. Patent 2,839,448, issued August 17, 1958, and DiGiuolio, 3,862,307, issued January 21, 1975. These patents are incorporated herein by reference.

1 3 n,.,, 71226 D. Wetting Agent Another +> 11 important component of these toothpaste compositions is a wetting agent. In the field of toothpaste fit in „4.11 +„ „.

^ Λοε drift drives are also well known. The wetting agent retains koo-t-0>, ++ - "'b-eui.ta] a thus preventing the curing of the toothpaste compositions; 1ιη,„ „, .......

-c.ssa. certain wetting agents may also, as desired, or ν ,, + 4-3n y help the sweetness and taste of the toothpaste compositions. Usually wetted, lc1 Q ^ J -usa i they form n.

5-55, preferably about 20-36% by weight of the weight of the paste compositions to be treated.

Kostnt ,, e ,, 1'.n · useful in this invention.

J-novel amides are edible polyhydric alcohols such as glycerin r-ο-ηκ · ^ · orpitol, xylitol and propylene glycol i. Usually sorbitol is called "- s · -;", vn o · „-L.ir, J ^ ayceca / O-nise as an aqueous solution called Sorbo ^. Glycerin i.

Mixtures of 3 - and sorbitol are especially recommended for the treatment.

3 as a wetting agent component for toothpaste compositions.

E. Water.

The second toothpaste of the toothpaste of the present invention; v m t.

-Heavy The component is water. The water used in commercially suitable toothpastes must be: i.on j. replaced and it does not „, J J receives oija organic impurities. The amount of water is about 15-80%, preferably about 15-30% by weight of the toothpaste compositions to be treated.

F. Optional Ingredients

An essential component of the above is the toothpastes of the invention may contain a variety of conventional toothpaste ingredients. Such: s'a optional Pneonh are 1) blowing agents. 2) membrane penetrants, 3) flavors and flavorings, 4) greens against tartar and plaque, and 6) pigments and dyes.

1) Foaming agent

The recommended optional ingredient is a blowing agent. Suitable blowing agents are relatively stable and form a foam over a wide pH range, e.g., soap-free, anionic, nonionic, cationic, zwitterionic, and amphoteric organic synthetic detergents. Flotation of this type: East is described in more detail in Agricola et al., U.S. Patent 3,959,458, issued May 25, 1975, and 14,71226

Kaefele, U.S. Patent 3,937,807, issued February 10, 1976. Both patents are incorporated herein by reference.

Union foaming agents useful herein include water-soluble salts of alkyl sulfates having from 8 to 18 carbon atoms in their alkyl radicals and water-soluble salts of suffocated monoglycerides of fatty acids having from 10 to 18 carbon atoms. Examples of this type of anionic pmta-active greed are sodium lauryl sulfate and sodium coconut monoglyceride sulfonates. Mixtures of Union surfactants may also be used.

The nonionic blowing agents useful in the toothpastes of the present invention can be broadly defined as compounds formed by condensation of alkyleneoxy groups (hydrophilic in nature) with an organic hydrophobic compound which may be an alkylate or an alkyl Aromatic. Examples of suitable non-ionic flotation are Pluronics, polyethylene oxide condensates of alkylphenols, products obtained by condensing ethylene oxide with the reaction product of propylene oxide and ethylenediamine, long-chain ethoxy-ethylate oxide condensates of aliphatic alcohols, extrinsic phosphine oxides, long dialkyl sulfoxides and mixtures of such materials.

The zwitterionic synthetic blowing agents useful in the toothpastes of the present invention can be broadly defined as aliphatic, quaternary ammonium phosphonium derivatives and sulfonium compounds, the aliphatic radicals of which may be straight or branched and one of which is aliphatic. carboxy, sulfonate, sulfate, phosphate or phosphonate.

The cationic blowing agents useful in the toothpastes of the present invention can be broadly defined as quaternary ammonium compounds having one long, n.

An alkyl chain containing 8 to 5 carbon atoms, e.g., lauryltrimethylammonium chloride, cetylpyridinium chloride, cetyltrimethylammonium bromide, diisobutylphenoxyethoxyethyldimethoxybenzylammonium chloride, coconut alkyltrimethylammonium nitrileyrimide or Particularly preferred are the quaternary 71226 ammonium fluorides described in U.S. Patent 3,535,421.

Briner et al., Published 20,10,1970, incorporated herein by reference. Said quaternary ammonium fluoride has a cleaning effect. In certain toothpastes in the process, cat blowing agents may also act as Germi side 1.

Amphithetic blowing agents useful in the present invention can be broadly defined as a derivative of aliphatic secondary and tertiary amines, therefore, the aliphatic radical of which may be straight or branched, and in which one of the aliphatic substituents contains about 8 to about 18 carbon atoms and hydrogen. , e.g. carboxylate, sulfonate, sulfate, phosphate or phosphonate.

In the toothpaste compositions of this invention, the amount of blowing agent may be 0.1 to 6% by weight of the total composition.

2) Phosphate Transmittants The toothpaste compositions of the present invention preferably contain about 5-12, preferably about 7-11% by weight of a water-soluble phosphate "permeate" component. Such soluble phosphate salts promote the migration of fluoride ions through the membrane inherent in saliva on teeth. Fluoride-containing toothpastes having the amounts of phosphate salts proposed herein have better fluoride diffusion through the membrane and better fluorine dinotto of the enamel compared to fluoride toothpastes that do not contain such phosphate membrane permeation agents.

Although relatively large amounts of soluble phosphate salts can improve the fluoride membrane permeability of fluoride toothpastes, such salts can also reduce the storage stability of soluble fluoride in such toothpastes. However, it has surprisingly been found that such soluble phosphate salts can be added to the silica-containing fluoride toothpastes discussed herein, especially with improved fluoride compatibility, if the present alkaline earth metal treated precipitated silica abrasives are used.

Optional phosphate salts of the treated toothpaste compositions are water soluble. In the present invention, the "water-soluble" phosphate salt has a solubility in water of at least 3.0 g / 100 ml of water at 20 ° C.

Phosphates are phosphorus compounds already in the anion of each phosphorus atom surrounded by four oxygen atoms at the corners of the tetrahedron. By connecting oxygen atoms between tetrahedra, chains, rings and branches, polymers formed by interconnected PO 2 tetrahedra are obtained. Simple phosphates are orthophosphates. Polymeric phosphates include polyphosphates such as pyrophosphates and tripolyphosphates. Ring phosphates are metaphosphates.

Examples of water-soluble polyphosphates useful herein include tetrapotassium pyrophosphate, tetrasodium pyrophosphate, disodium pyrophosphate, sodium tripolyphosphate and potassium tripolyphosphate. Examples of suitable water-soluble metaphosphates are monopotassium metaphosphate, sodium trimetaphosphate, sodium hexametaphosphate and sodium heptametaphosphate. Many of these water-soluble polyphosphates and metaphosphates are used in the form of hydrate salts.

Of the phosphate salts used in the present invention, the most preferred are simple orthophosphate salts. The orthophosphate salts are derived from the tribasic orthophosphoric acid of formula H2O. Water-soluble sodium, potassium and ammonium salts can be used.

There are about ten different crystalline sodium orthophosphate salts, including different hydrates. These include, for example, NaH 2 PO 4, NaH 2 PO 4 -H 2 O, NaH 2 O 2 · 2H 2 O, Na 2 PO 2, Na 2 HPO 4 · 2H 2 O, Na 2 HPO 4 · 7H 2 O, Na 2 HPO 4 · 12H 2 O, Na 3 PO 4 · 6H 2 O, Na 3 PO 4 · 8H 2 O and mixtures thereof. Preferred sodium orthophosphates are Na 2 PO 2 d 2 O 2, Na 2 HPO 4 · 2H 2 O and mixtures thereof.

Particularly preferred are mixtures of NaH 2 PO 4 * H 2 O and Na 2 HPO 4 · 2H 2 O in a weight ratio of monosodium and disodium salt of about 1: 3 to 1: 5.

In this connection, potassium and ammonium orthophosphates can also be used as film-permeable substances. Examples of such potassium and ammonium salts are KH 2 PO 4, K 2 HPO 4, K 2 HPO 4 "2H 2 O, K 2 HPO 2 * 6H 2 O, K 3 PO 4 -3H 2 O, K 3 PO 4 - 7H 2 O, K 3 PO 4 * 9H 2 O, (NH 4) H 2 PO 4, (NH 4) 2 HPO .

A particularly preferred phosphate salt mixture for use in these toothpastes is a mixture of Naf 2 PO 2 · H 2 O and K 2 HPO 2 · 2H 2 O in a weight ratio of sodium to potassium salt of about 1: 3 to 1: 5.

The soluble phosphate salts of the present invention are commercially available. Phosphate salts useful herein are described in more detail in Kirk & Othmer, Encyclopedia of Chemical Technology, Second Edition, Volume 15, Interscience Publisher's, Inc.

(1968), pp. 232-276, incorporated herein by reference.

Preferably, the toothpaste compositions of the present invention have a phosphate salt concentration of about 0.5 to 2.0 moles / 1,000 g of water in aqueous solutions that come into contact with tooth surfaces when the toothpastes of the present invention are used in the mouth. Even then, such working solutions are imitated with a liquid on top of 3: 1 suspensions of water and toothpaste.

Other membrane permeation agents may optionally be added to the fluoride-containing toothpastes of the present invention. Such optional ingredients further enhance the fluoride membrane permeation benefits achieved with the present phosphate salts. Such substances include, for example, hydroxy acids and their salts, such as citric acid, trisodium citrate, malic acid and tartaric acid. The amount of such patch membranes is about 0.2 to 5.0% by weight of the toothpaste composition.

3) Flavorings Flavorings may also be added to the present compositions. Suitable flavors include gaulter oil, peppermint oil, green mint oil, sassafras oil and cloves oil. Useful sweeteners include saccharin, dextrose, levulose, aspartame, D-tryptophan, acetosulfarone, dihydrocalcones and sodium cyclamate. The amount of flavors in the toothpaste is usually about 0.01 to 2% by weight and the amount of sweeteners is about 0.05 to about 3% by weight.

4) Anti-plaque / tartar agent Phosphorus-containing anti-tartar agents and / or anti-plaque agents may also be optionally added to the toothpastes of the present invention. Phosphorus-containing anti-calculus agents, such as disodium ethane-1-hydroxy-1,1-diphosphonate and the like, are described in more detail in McCune et al., U.S. Patent 7,1226,188 3,488,419, issued January 6, 1970, which is incorporated herein by reference. Anti-plaque bi sbif Unni di a ine such as chlorohexyl (1,6-bis- / N-p-chlorophenyl-M-biguanido) hexane), its soluble and insoluble salts and the like, such as 1, 2-Bis- (N-p-trifluoromethylphenyl-N-biguanido) ethane is described in more detail in Haefele, U.S. Patent 3,934,002, issued January 20, 1976, Haefele, U.S. Patent 3,937,807, issued February 10, 1976, Procter &. Gamble, Belgian Patent 843,244, issued December 22, 1976, and Procter & Gamble, Belgian Patent 844,764, issued January 31, 1977. These patents are incorporated herein by reference.

The amount of optional tartar and / or anti-plaque agents is usually about 0.01 to 2.5% by weight of the treated toothpaste compositions.

5) Pigments and Dyes, Miscellaneous Several other optional components well known in the art may be added to the toothpaste compositions to be treated to enhance the comfort of use in the usual manner. These include, for example, pigments, dyes and mottles. The amount of these optional components is generally from about 0.001% to about 2% by weight of the treated toothpaste.

Preparation of the Composition The toothpaste compositions of the present invention are prepared simply by mixing the essential and optional components mentioned herein in the desired order and by conventional means. The compositions thus prepared have a pH of about 4.0 to 8.0, preferably 6.5 to 7.5, slurried in water in a weight ratio of water to composition of 3: 1. Fluoride toothpastes with a pH of 4.0 to 8.0 achieve a particularly effective insolubility of tooth enamel compared to toothpastes with pH values outside this range. Seasoning toothpastes with this pH range is also relatively easy.

Use of the Composition The toothpaste compositions of the present invention are used in a conventional manner. The toothpaste compositions or their slurries are brushed on the tooth surface and then rinsed off.

19 71 226 When the toothpaste in question is used in the usual way, it takes at least about 30 seconds for the pastes or sludges to come into contact with the tooth surfaces. Preferably, this contact time is at least about 60 seconds.

The following examples illustrate the present invention without limiting it. In the following examples, parts are by weight unless otherwise indicated.

Example 1

To a 30,000 L stainless steel steam-jacketed reactor was added 1,794 L of sodium silicate solution (3.78% Na 2 O, 9.53% SiO 2), density 1.121 and containing 42 g Na 2 O / l. The reaction medium was heated to 88 ° C with constant stirring. At this point, 10% sulfuric acid (density 1.066) and sodium silicate solution were added simultaneously to the reaction medium at a rate of 151.4 l / min of acid and 351 l / min of sodium silicate, maintaining the reaction temperature of 88 μl. The two solutions were added to the reaction medium for a predetermined time. The addition of silica was stopped after 47 minutes, but the addition of acid was continued until the pH of the slurry was 4.8 to 5.0. The reaction slurry was boiled at 100 ° C for 20 minutes and the reaction pH was readjusted to 4.8-5.0. The silica slurry formed was filtered, washed to remove most of the reaction by-product (sodium sulfate), the filter cake was dried, and the dry product was ground to the desired particle size. Various physicochemical experiments were performed on dry silica and their analysis is shown below (see Table I). In this example, a control product to which no alkaline earth metal had been added was prepared.

Example 2

To a 30,000 L stainless steel steam-jacketed reactor was added 1,794 L of sodium silicate solution (3.78% Na 2 O, 9.53% SiO 2), density 1.121 and containing 42 g Na 2 O / L. The reaction medium was heated to 88 ° C with constant stirring. At this point, 10% sulfuric acid (density 1.066) and sodium silicate solution were added simultaneously to the reaction medium at a rate of 151.4 L / min of acid and 351 L / min of sodium silicate while maintaining a reaction temperature of 88 μC. . The addition of silicate was stopped after 47 minutes, but the addition of acid was continued until the pH of the slurry was 4.8 to 5.0. The reaction slurry was boiled at 100 ° C for 20 minutes and the reaction pH was readjusted to 4.8-5.0. The silica slurry formed was filtered and washed to remove most of the reaction by-product (sodium sulfate).

The washed filter cake was then reslurried without the addition of water at ambient temperature with stirring. During mixing, the slurry was treated with 102 g of Codex grade (US food grade) hydrated lime (calcium hydroxide) to give a calcium ion treatment of 25 ppm based on the dry recovered product in sludge form. After the calcium ion treatment, the slurry cake was stirred vigorously for 15 minutes to provide an effective amount of calcium ions on the surface of the silica abrasive. The resulting product was then spray-dried at an inlet temperature of 483 ° C and an outlet temperature of 122 ° C, ground and the abrasion and physical properties determined in the same manner as with the abrasive of Example 1.

Example 3 The procedure of this example was the same as that of Example 2, except that the rate of addition of sulfuric acid was 162.7 l / min and the addition of calcium was 204 g of calcium hydroxide, giving an amount of calcium ions of 50 ppm. The product characteristics were then determined.

Example 4 This example was the same as Example 2, except that the rate of addition of sulfuric acid was 166.5 l / min and the addition of calcium was 408 g of calcium hydroxide, giving a calcium ion content of 100 ppm. The product characteristics were then determined.

Example 5 In this example, a silica abrasive for a dentifrice was prepared by first adding 1,420 L of a sodium silicate solution (4.09% Na 2 O, 10.31% SiO 2), a density of 21,71226 and containing 46.3 g Na 2 O / L to the reactor as a reaction medium. The reactor was heated to 91 ° C with constant stirring. At this point, 12% sulfuric acid (density 1.08) and sodium silicate solution were added simultaneously to the reaction medium at a rate of 162.7 L / min of acid and 315.7 L / min of sodium silicate, maintaining the reaction temperature at 91 ± 1 ° C. The addition of Si-licate was stopped after 47 minutes, but the addition of acid was continued until the pH of the slurry was 4.6-4.8. The reaction science was boiled at 100 ° C for 20 minutes and the pH of the reaction was adjusted again to 4.6-4.8. The silica slurry formed was filtered and washed to remove sodium sulfate by-product.

The washed filter cake is then reslurried without the addition of water at ambient temperature with stirring. During mixing, the slurry was treated with 510 g of Codex grade (US food grade) hydrated lime (calcium hydroxide) to give a calcium ion treatment of 125 ppm based on the total weight of the dry abrasive in the form of a slurry. After the calcium ion treatment, the slurry cake was stirred vigorously for 15 minutes to obtain an effective amount of calcium ium i one on the surface of the silica. The resulting product was then spray dried at an inlet temperature of 483 ° C and an outlet temperature of 122 ° C, ground and the characteristic values determined.

Example 6 This example was the same as Example 5 except that 1,608 L of sodium silicate solution was initially charged to the reactor as the reaction medium and the acid addition rate was increased to 170.3 1 / min, but the silicate addition rate was maintained at 315.7 L / min.

The washed filter cake was treated with 816 g of calcium hydroxide and a calcium ion treatment of 200 ppm was obtained on the surface of the silica abrasive. The product characteristics were then determined.

Example 7 This example was the same as Example 2 except that the calcium ion addition was 2,040 g of calcium hydroxide, which represented 500 ppm of calcium ions. The product characteristics were then determined.

After preparation of the products of Examples 1-7, their physical properties were determined and the results are shown in Table I below.

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The following examples illustrate several representative toothpastes of the present invention using the present precipitated silica abrasives.

Example 8

A toothpaste was formulated using the doped silica abrasive of Example 2. Its composition was as follows:

Component Amount by weight of precipitated silica abrasive (Example 2) 16.0 sodium fluoride (NaF) 0.28 sorbitol solution (70%) 32.0 glycerin 13.0 sodium carrageenan 0.75 monosodium orthophosphate monohydrate (NaH ^ PO ^ Ή ^ Ο) 2.15 disodium orthophosphate dihydrate (Na 2 HPO 2 · 2H 2 O) 8.34 sodium alkyl sulphate solution (28.8%) 6.0 coconut monoglyceride sodium sulphonate 0.9 flavor 1.22 sodium saccharin 0.3 colorant (FD & G blue No. 1.1% solution) ) 0.35 titanium dioxide (TiO 2) 0.5 trisodium citrate dihydrate (CgH 2 Na 2 O 2 · 2H 2 O) 0.25 distilled water qs

amount 100.0

The above toothpaste composition is prepared by mixing its components in the normal manner known in the art of toothpaste preparation. Preferably, the aqueous component is first added to a suitable container, to which film permeation agents, flavoring agent, wetting agent, and finally other components are then added in moderate order.

The pH of the 3: 1 suspension (water: composition = 3: 1) in the weight ratio of the freshly prepared composition to water was about 7.1.

Such a toothpaste composition achieves good fluoride treatment of the brushed tooth tissue due to the good fluoride compatibility of the toothpaste. The toothpaste also achieves good cleaning performance and an RDA value of 100. When storing long periods of time, 24 71226

. C

at 27 ° C, the loss of soluble fluoride from such toothpaste is minimal.

Toothpastes which achieve approximately the same fluoride treatment benefits, fluoride compatibility and cleaning performance of the toothpaste are obtained by replacing sodium fluoride in the composition of Example 8 with an equivalent amount of stannous fluoride, sodium chlorofluoride, potassium fluoride, potassium fluoride, potassium stannofluoride,

Toothpastes which achieve approximately the same fluoride treatment benefits and approximately the same cleaning performance are obtained by replacing the phosphate salt mixture in the composition of Example 8 with an appropriate amount of Na 2 PO 2, NaH 2 O 2 · H 2 O, NaH 2 PO 2 · 2H 2 <3, Na 2 HPO 4, Na 2 HPO * 2H 2 O, Na 2 PO 2 7H 2 O, NagPO 2 · 6Η? 0, NagPO 2 · 8H 2 O, KH 2 PO 4, K 2 HPO 4, K 2 HPO 2 -2H 2 O, K 2 HPO 4 - 6H 2 O, Κ 3 × 0 4 · 320, K 3 PO 4 * 7H 2 O, K 3 PO 4 - 9H 2 O, (NH 4) (NH1 +) 2HPO1 +, (ΝΗ4) 3ΡO4, other mixtures of NaH2PO4-H2O and Na2HPO4 · 2H2O in a weight ratio of monosodium and disodium of about 1: 3 to 1: 5, NaH.PO., -HCO0 and KoHPO . · Ho0 the sodium and potassium salt in a weight ratio of 1:?. 3 to 1: 5, tetrakaliumpyrofosfaat-acetate, tetrasodium pyrophosphate, Disodium pyrophosphate, sodium tri-polyphosphate, potassium tripolyphosphate, monokaliummetafosfaatti, sodium trimetaphosphate, sodium hexametaphosphate or natriumhep-tametafosfaatti provided that such compositions The pH of 3: 1 suspensions is 4.0 to 8.0.

Example 9

A high abrasive toothpaste was formulated using the precipitated silica abrasive of Example 3. Its composition was as follows:

Component Amount by weight of precipitated silica abrasive (Example 3) 35.0 sodium fluoride (NaF) 0.22 glycerin 5.0 sorbitol solution (70%) 20.0 carboxymethylcellulose (DS = 0.7) 0.5 magnesium aluminosilicate (Veegum flakes) 0.3 monosodium orthophosphate iminohydrate (Nal-I ^ PO 2 · H 2 O) 0.3 25 71 226 disodium orthophosphate dihydrate (Na 2 HPO 2 · 2H 2 O) 0.3 sodium alkyl sulphate solution (28.8%) 2.3 coconut monoglyceride sodium sulphonate, 7 flavors 0.9 sodium saccharin 0.2 titanium dioxide (TiCl 2) 0.5 spotting 0.5 distilled water q. p.

amount 100.0

Toothpastes which achieve substantially the same fluoride treatment benefits, fluoride compatibility and cleaning performance of the toothpaste are obtained by replacing the precipitated silica abrasive prepared in Example 3 in the composition of Example 9 with an equivalent amount of the abrasives prepared in Examples 2.9, 5 and 6.

Toothpastes which achieve approximately the same fluoride treatment advantages and approximately the same cleaning performance are obtained by replacing the phosphate salt mixture in the composition of Example 9 with an appropriate amount of NaH 2 PO 2, NaH 2 PO 2, Na 2 H 2 O 2, 2 H 2 O, Na 2 HPO 4, Na 2 HPO 2, Na 2 HPO 2 Na ^ PO ^ · 7H 2 O, Na ΝΗ4) 2ΗΡ04, (ΝΗ4) 3Ρ04, other mixtures of NaH2PO4 · Η? 0: η and Na2HPO4 * 2Η20 in a weight ratio of monosodium and disodium of about 1: 3 to 1: 5, NaH2PO2 + · H2O and KgHPO2 · 2H2O mixtures of sodium and potassium salt in a weight ratio approx. 1: 3 to 1: 5, tetrakaliumpy-pyrophosphate, tetrasodium pyrophosphate, Disodium pyrophosphate, sodium tripolyphosphate, potassium tripolyphosphate, monopotassium phosphate, sodium trimetaphosphate, sodium hexametaphosphate or natriumheptametafosfaatti provided that such compositions of a 3: 1 pH of the suspension is 9.0 - 8.0.

Example 10

A clear toothpaste was formulated containing the precipitated silica abrasive of Example 9. Its composition was as follows: o c 71226

Component Amount by weight of precipitated silica abrasive (Example 4) 20.0 sodium fluoride (NaF) 0.24 sorbitol solution (70%) 57.0 glycerin 15.0 sodium carrageenan 0.5 phosphoric acid (85%) 0.10 sodium alkyl sulphate solution (28.8 %) 4.0 flavor 1 o sodium saccharin 0.2 dye (FD&C blue no. 1.1% solution) 0.05 distilled water qs

amount 100.0

Example 11

A low abrasive toothpaste was formulated containing the precipitated silica abrasive of Example 3.

Its composition was as follows:

Component Amount by weight of precipitated silica abrasive (Example 3) 6.0 stannofluoride (SnF 2> 0.40 sorbitol solution (70%) 51.0 glycerin 25.6 sodium carboxymethylcellulose (DS = 0.7) 1.0 sorbitan monoisostearate 2.00 sodium alkyl sulfate 28.8%) 6.0 flavoring 1, 20 sodium saccharin 0.28 coloring (FD & C blue no. 1.1% solution) 0.25 X) pyrophene, colloidal silica (Aerosil 200V) 5.00 distilled water qs

amount 100.0 X)

Marketed by Degussa, Inc.

Toothpastes having substantially the same fluoride treatment benefits, fluoride compatibility of toothpaste and cleaning efficiency are obtained by replacing the precipitated silica abrasive component prepared in Example 10 in the composition of Example 10 with an equivalent amount of the abrasive prepared in Examples 2, 3, 5 and 6.

A toothpaste that achieves approximately the same fluoride treatment benefits and an improved anti-calculus advantage is obtained when the composition of Example 10 further contains about 1.0% by weight of disodium ethane-1-hydroxy-1,1-diphosphonate.

Testing and Determination These precipitated silica abrasives can be used in the preparation of particularly desirable therapeutic toothpaste compositions containing soluble phosphate film penetrants. Such compositions achieve both good fluoride compatibility of the abrasive and good tooth cleaning performance. The purpose of the following tests and assays is to demonstrate the excellent fluoride compatibility of the dental silica abrasives in the toothpaste compositions of the present invention. It will also be shown below that the abrasives of the present invention achieve a higher fluoride compatibility of the abrasive than correspondingly prepared abrasives that have not been treated to contain substantial amounts of alkaline earth metal materials. In addition, the excellent cleaning performance of the toothpaste compositions discussed herein is demonstrated. Finally, it is shown here that abrasives prepared by the sulfate liquid acidification process - even if they contain alkaline earth metal materials - are unable to provide the high fluoride compatibility values of the "fresh water" precipitated silica abrasives provided herein.

Fluoride compatibility of abrasive

The relative compatibility of precipitated silica dentifrices with fluoride materials can be determined by a 24-hour abrasive suspension test. Thus, values are obtained which allow the prediction of the available soluble fluoride in certain types of fluoride toothpastes after about four weeks of storage at 27 ° C.

The 24-hour test of the abrasive suspension is used to obtain fluoride compatibility values, defined as a percentage of the theoretical maximum value of 28 71 226 available fluoride, which is practically measured after 24 hours as soluble fluoride by the following test method. In this method (Orion ion-specific electrode method), a sodium fluoride standard stock solution containing 1624 ppm fluoride is prepared by dissolving 2.80 g of sodium fluoride, 21.5 g of NaH 2 O 2 and 83.4 g of NaHPO 2 in 672.5 g of deionized, distilled water and stored in a polyethylene bottle. 30 g of this solution were then weighed. 7 g of the test silica abrasive was dispersed in the solution and allowed to come into contact for 24 hours at a temperature of about 38 ° C. After twenty to four hours, the abrasive fluoride precipitate solution was centrifuged for 20 minutes at 15,000 rpm or until the supernatant was clear. 10 ml of supernatant was then pipetted into a plastic ampoule. 10 ml of EDTA / THAM solution was then pipetted into the plastic ampoule. The EDTA / THAH solution is 0.2 molar with respect to EDTA (disodium salt of ethylenediaminetetraacetic acid) and 0.2 molar with respect to THAM (2-amino-2-hydroxymethyl-1,2-propanediol), pH adjusted to 8.0 sodium hydroxide11a. Add a magnetic rod and start stirring slowly. The fluoride ion concentration is determined directly potentiometrically on the Orion fluoride electrode 11a (model 95-09). The emv of the supernatant is converted to parts per million (ppm) using a logarithmic equation. The fluoride compatibility value is calculated by expressing the measured ppm value of soluble fluoride as a percentage of the theoretical value of the available soluble fluoride.

Using this method, the relative fluoride compatibility values of the abrasive prepared according to several examples Λ · -Ί were determined. The results of such an assay are shown in Table II below.

29 71226

Table II

Abrasive fluoride compatibility

Example No. Calcium treatment (ppm) Abrasive fluoride compatibility 1 (control) 0 76% 2 25 93% 3 50 94% 4 100 93% 5 125 91% 6 200 90% 7 500 88%

The values in Table II show that these precipitated, e.g. silica abrasives containing amounts of alkaline earth metal achieve a clearly better fluoride compatibility of the abrasive than abrasive without alkaline earth metal, otherwise prepared in the same way. Thus, the precipitated silica abrasives prepared according to Examples 2-6 are suitable for the preparation of toothpastes containing fluoride and film-permeable agents having a high abrasion compatibility of the abrasive.

Abrasive Fluoride Compatibility in Toothpastes The abrasive fluoride compatibility of these recommended toothpastes containing precipitated silica abrasives and membrane penetrants was determined. The test toothpastes had the composition of the toothpaste of Example 8 and differed only in the abrasive component.

To determine the fluoride compatibility values of the test toothpastes, the soluble fluoride determination method was used, which was the same as the abrasive fluoride compatibility value determination method above. In this method, toothpaste compositions were stored for a specified time in a laminate tube. Then 15.0 g of the composition was placed in a 100 ml decanter and 45.0 g of distilled water was added. The mixture was mixed into a suspension in which the toothpaste is uniformly dispersed. The suspension was centrifuged for 20 minutes at 15,000 rpm or until the supernatant was clear.

3 ° 71226

The supernatant was then treated as in the abrasive fluoride compatibility assay method described above. Ko. fluoride compatibility values for toothpastes are shown in Table III. The abrasives determined are the same as those prepared according to Examples 1-7 and their characteristic values are shown in Table I above.

Table III

Fluoride compatibility of toothpaste

Abrasive Calcium treatment Fluoride compatibility (eg no.) (Ppm) of toothpaste (1 week, 27 ° C) 1 (control) 0 76% 2 25 99% 3 50 98% k 100 99% 5 125 97% 6 200 94 % 7,500 90%

The values in Table III show that these preferred toothpastes using the precipitated silica abrasives in question provide excellent abrasive fluoride compatibility values compared to the corresponding toothpaste composition containing an alkali metal untreated silicon compound prepared by the process of Example 1. In addition, the values in Table III indicate that the amount of soluble fluoride available from the fluoride ion source material is not significantly reduced during storage when the silica abrasives of the present invention are used in these preferred toothpastes.

Of course, it should be noted that the amount of soluble fluoride available in these toothpaste compositions also decreases to some extent as a function of the increase in storage time and temperature. Thus, toothpaste stored for extended periods of time or at different temperatures generally have lower fluoride compatibility values than the above example toothpastes.

Additional fluid compatibility compatibility values for various toothpastes stored at elevated temperatures for longer periods of time are shown in Table IV.

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The values in Table IV indicate that these Recommended Toothpastes retain their relatively high levels of fluoride compatibility of the abrasive during long-term storage or difficult storage conditions.

Cleaning performance The teeth cleaning performance of these silica abrasives can be determined using the Radioactive Method of Tooth Bone Wear (RDA). RDA values can be used to determine the relative cleaning performance of different types of dentifrices for all types of dentifrices. Thus, precipitated silica-abrasives require an RDA value (as determined below) of at least 40 and preferably 70-120 to ensure that the abrasive effect of the abrasive is sufficient to obtain an effective dentifrice. Prior art precipitated, high toothpaste fluoride-compatible silica abrasives are generally poor cleaners in oral hygiene, as evidenced by low RDA values. But alkaline earth metal-treated abrasives offer both efficient tooth cleaning and high fluoride compatibility.

To determine RDA values, several commercial precipitated silica abrasives were selected that had a relatively high fluoride compatibility of toothpaste as measured herein. The assay was performed with a standard toothpaste matrix having the same composition as the toothpaste of Example 8, differing only in the variation of the abrasive component.

The method used to determine the RDA values of the toothpastes shown in Table V is described below. This test method is described in more detail in Hefferren, Journal of Dental Research, July-August, 1976, pp. 563-573. The individual steps in determining RDA values are as follows: A. Selection and preparation of teeth

Healthy, single-root permanent teeth that were free of tooth decay at the time of removal and that were viable were selected. They were scraped clean with a scalpel. The crown and root tip of each tooth were removed with a grinding wheel to obtain a dental bone sample 14 mm long and at least 2 mm wide at the narrower end. 33 71 2 2 6 are also used to prepare chopped roots (bone fragments) or, alternatively, an additional tooth for later use to determine the self-absorption correction factor for irradiation.

B. Irradiation of dentin

The prepared roots and bone fragments described in A were irradiated for three hours at a neutron flux of 2 x 10 10 neutrons / cm 2.

C. Root Attachment After irradiation, the irradiated roots were attached to a cold-curable dental methacrylate resin and mounted on a po.i putty brush machine. Throughout the experiment, 50 bristles, medium-sized, flat "Pepsodent" toothbrushes were used.

D. Pretreatment of tooth surfaces

Prior to the start of the experiment, freshly mounted, irradiated roots were brushed with a reference suspension (10 g calcium pyrophosphate + 50 ml 0.5% CMC - 10% glycerin solution) using 6,000 brush strokes. At the beginning of each subsequent day's experiment, the roots were brushed with 1,000 strokes.

E. Execution of the test

After pretreatment, dental bone samples were treated with the reference suspension (same as in step D) with 1,500 brush strokes at the beginning, during, and at the end of each test run. The experiment was performed by brushing dental bone samples with 1,500 brush strokes using a suspension of test product (25 g of dentifrice + 40 ml of deionized, distilled water).

F. Preparation of correction factors

Correction factors were prepared by dissolving the dentin pieces or additional tooth in B in 5 ml of concentrated hydrochloric acid and made up to volume with 250 ml of distilled water. 1 ml of this solution was added to test pastes and reference suspensions prepared as in E and neutralized with 0.1 N NaOH solution.

34 71226

Determination of tracer radiativity

The radioactivity of the suspension samples (1.0 ml) was determined on an Intertechnique SL-30 liquid scintillation counter 1.1a. Alternative assay method: 3 ml aliquots of each suspension were transferred to stainless steel flat bottom 75.4 x 7.9 mm discs and counted on a Nuclear Chicago Geiger Counting System.

bills

Ko. the radiosolysis value (RDA) of the paste on the dentin is the ratio of the mean of the corrected pulses of the paste to the mean of the pulses of the reference substance multiplied by 100. The reference abrasive is given an arbitrary value of 100 units of dentition.

The results of the determination of such RDA values are shown in Table V below.

Table V

Radiation rates of osteoporosis

Abrasive RDA Fluorescence of toothpaste (1 week 27 ° C) A. (eg no.) 1. control 75t7 76% 2. 80 ± 21 99% 3. 67 + 8 98% 4. 80 ± 1 99% 5. 103 ± 5 97% 6. 111 ± 5 94% 7. 56 + 4 90% B. Commercial precipitated silica products 8. Sident 31 14 + 2 92% 9. Neosyl2 25 + 2 78% 10. QUSO G-303 22Ϊ2 87% 11. Neosyl ET4) 26 + 4 84%

Alloyed silica, marketed by Degussa, Ins. (N.Y.C.) 2

Precipitated silica, marketed by Joseph Crosfield & Sons, Ltd.

3 (London, England) 35 71 226 3) Precipitated silica, marketed by Philadelphia Quartz Co.

(Valley Forge, Pa.) K) Precipitated silica, marketed by Joseph Crosfield & Sons, Ltd.

The values in Table V indicate that commercial doped silica abrasives may well have good abrasive fluoride compatibility, but they do not have sufficient abrasive performance and thus are not useful dentifrice abrasives. Surprisingly, the new doped silica abrasives in the present case provide excellent abrasive fluoride compatibility and yet excellent RDA abrasion values that can be used as a measure of relative tooth cleaning performance.

"Fresh water" and "sulphate liquids" - abrasives

As discussed above, the abrasion products of the present invention are related. U.S. Patent Application 826,901 for calcium-treated silicas, but clearly differ from them. To demonstrate this difference, the following assay was performed to compare the fluoride compatibility of the products of U.S. Application 826,901 and the abrasion products of this invention. The tested "sulfate liquid" silicas were prepared according to the method of U.S. Application 826,901 and U.S. Patent 3,960,586, issued June 1, 1976, as follows:

Dry sodium sulfate was added to 38.0 liters of water in a 760 liter reactor so that the concentration of the reaction medium was 10%. The pH of the reaction medium was adjusted to 9.0 by the addition of sodium sulfate. The reaction temperature was 65 ° C. The sodium silicate solution had a SiO 2 · Na 2 O molar ratio of 2.5 and a concentration of 239.6 g / l. Sodium silicate was added to the reaction medium for four minutes. At this point, the addition of sodium silicate was stopped and 11.4% sulfuric acid was added to the reaction medium until pH 9, C was reached. At this point, sodium silicate solution and sulfuric acid solution were added simultaneously for 35 minutes. At the end of this time, the silicate addition was stopped and the acid addition was continued until the pH of the suspension was 5.5. The batch was digested for 20 minutes at 77 ° C, the formed wet cake was isolated and washed.

The wet cake was then treated as in Example 2 of this patent application, divided into six separate parts, and handled with 50, 100, 200, 400, and 800 parts per million of calcium from an aqueous solution of calcium hydroxide, respectively. All wet cakes were then dried, processed as in Example 2 and in Table VI below. The first abrasive is a control without the addition of calcium. Table VI shows the results of such an assay.

Table VI

"Sulphate liquid" - Ca addition (pnm) Fluoride compound of abrasive,. *. +) Abrasive suitability A 0 8 8 (control) B 50 89 C 100 88 D 200 88 E 400 86 F 800 82 +) Determined by experiment in Table II

As can be seen from the values in Table VI, the calcium-treated "sulfate liquid" abrasives of U.S. Patent Application 826,901 achieve fluoride compatibility values for the abrasive that are generally less than those obtained with the "fresh water" silica abrasives of the present invention (see Table II). In addition, the addition of an alkaline earth metal to abrasives prepared by the "sulfate liquid" method does not result in a dramatic improvement in the fluoride di-compatibility of the abrasive. But, as can be seen from the comparison in Table II, the addition of alkaline earth metal equivalents to these silica freshness abrasives prepared by the "fresh water" process results in a dramatic improvement in the fluoride compatibility of the abrasive.

Claims (18)

An abrasive composition for use in dental cleaning which contains a reaction product of amorphous silica and an alkaline earth metal prepared by precipitating the amorphous silica with an acid from an aqueous solution of the alkali metal silicate and reacting the silica with an alkaline earth metal salt, the amorphous silica has been precipitated with an acid from a freshwater solution of alkali metal silicate and reacted with an alkaline earth metal salt such that in the obtained amorphous silica there are about 10-300 parts of alkaline earth metal ions, and about 0.24-0.55 g / ml, oil absorption value about 70-95 cm 3/100 g, BET surface about 100-250 m 2 / g and annealing loss about 4-6%. Composition according to claim 1, characterized in that the alkaline earth metal ions are calcium, strontium and / or magnesium ions. Composition according to claim 1, characterized in that the amount of alkaline earth metal ions is about 10-100 ppm. 4. A composition according to claim 1, characterized in that the alkaline earth metal is calcium ion. Process for the preparation of a composition according to claim 1, in which process an aqueous solution of an alkali metal silicate having the molar ratio of S.iO 2 mXyO of about 0.10 to 75 is obtained, wherein X is an alkali metal, at a reaction temperature of about 7. 7 -91 ° C, acidifying with mineral acid until the silica has almost completely precipitated, continuing with the mineral acid addition to pH 6.0 or less, digesting at a temperature exceeding the reaction temperature by 10-30 ° C 10-30 minutes. filtering the resulting suspension and washing the solid product with fresh water, characterized in that it suspends the formation of the formed moist cake in water, while stirring with alkaline earth metal ion in the form of a sufficiently soluble alkaline earth salt 1 in sufficient amount; so that said moist cake obtains an addition of 10-300 million parts of alkaline earth metal ions based on the insoluble dry product in said suspension, stirring the formed mixture. u? The adhesive for adhering an effective amount of said alkaline earth metal to the surface of said silica dries and insulates the solid product. 6. Process according to claim 5, characterized in that the mineral acid is sulfuric acid, phosphoric acid, nitric acid, hydrochloric acid or carbonic acid. Process according to claim 6, characterized in that only part of the alkali metal silicate is quenched at the beginning with mineral acid and the remaining part adds to the alkali metal silicate solution simultaneously with the mineral acid. 8. A process according to claim G, characterized in that the alkaline earth metal ion is calcium, strontium or magnesium. 9. A process according to claim 6, characterized in that the alkaline earth metal ion is calcium and is added in the form of a site which is calcium hydroxide, calcium oxide, calcium nitrate or calcium fluoride. Process according to claim 6, characterized in that the alkaline earth metal salt is allowed to react with the suspension of the moist cake at ambient temperature. 11. A process according to claim 10, characterized in that the alkaline earth metal-treated silica is dried by spray drying. Process according to claim 6, characterized in that the alkali metal silicate is sodium silicate, the acid setting acid is sulfuric acid, the alkaline earth metal ion is added in the form of calcium hydroxide to obtain 10-300 million parts of calcium ions, which intimately reacted with said silica. 13. Toothpaste composition containing silica, a fluorine-containing material, wetting agent, binder and water, characterized in that it consists of A. about 6-35% by weight of precipitated silica abrasive material, which is a precipitated amorphous silica prepared from fresh-water alkali silica cat solution by acidification and reaction of the silica with a brine of an alkaline earth Imetali, such that said silica contains about 10-300 million parts of alkaline earth metal ions, said amorphous silica with a minimum of 40 about 5-15 µm, packing density 1.3 71 226 is called about 0.24-0.55 g / ml, oil absorption value about 70-95 cm 2/100 f, 3E 2 surface about 100-250 m 2 g and annealing loss about 4-6%, B. about G, 01-3, C wt% water soluble, fluorine-containing material, soit. forms fluoride ions in aqueous solution, C. about 3-55% by weight of a wetting agent, D. about 0.2-2.0% by weight of a binder model, and E. about 15-80% by weight of water. 14. Toothpaste composition according to claim 13, characterized in that the composition additionally contains about 5-12% by weight of the water-soluble tooth coating. Denitrates the phosphate agents, which are orthophosphate salts, pyrophosphate salts, trioolate phosphate salts or triophosphate salts. 15. Toothpaste composition according to claim 14, wherein it contains A. about 10-20% by weight of precipitated silica abrasive of the como. B. about 0.1-1.0% by weight of fluorine-containing material of the composition, C. about 2% to 35% by weight of wetting agent of the composition, E. about 15-40% of water component, and E. pH of a water composition suspension 3: 1 is about 6.5-7.5. 16. A composition according to claim 15, characterized in that the binder is carrageenan. 17. A composition according to claim 15, characterized in that the composition additionally contains about 0.2-5% by weight of the toothpaste composition of a second tooth coating penetrant, which is citric acid, trisodium citrate, malic acid or tartaric acid, and that A The fluorine-containing material is sodium fluoride, and B. The phosphate penetrating agent of the dental coating is a mixture of sodium hydrogen phosphate monohydrate and disodium hydrogen phosphate dihydrate in weight ratio monosodium to disodium about 1: 3-1: 5. 18. Toothpaste composition according to claim 15, characterized in that it contains an extra component which is A. about 0.01-2% by weight of a flavoring, B. about 0.05-3% by weight of a sweetener,