NO743476L - - Google Patents

Description

Toothpaste

Toothpastes usually contain finely divided abrasives dispersed in moisturizing carrier materials containing thickeners and/or gelling agents.

The invention relates to a toothpaste comprising a carrier

rial consisting of a wetting agent and in which a tooth grinding agent is dispersed which mainly consists of a finely divided material with a particle size of 2 - 20 ym and a silicon dioxide content of

at least approx. 70% and which has an amorphous X-ray structure, and the toothpaste ex is characterized by the fact that it is free of gum or et. another thickener soluble in the carrier material, and that the main abrasive consists of an alkali metal or alkaline earth metal aluminum silicate with an oil absorption value of up to approx. 165.

The main abrasive preferably has a refractive index which.

is approximately the same as the carrier material, e.g. 1.43 -- 1.48. The carrier material and main abrasive used in the present toothpaste are particularly useful for a transparent toothpaste.

According to the invention, the toothpaste must be essentially free of rubber, or another thickener soluble in the carrier material (water-soluble) and as the main abrasive contain an alkali metal or alkaline earth metal aluminum silicate, e.g. sodium aluminum silicate, with an oil absorption value' (according to ASTM D. 281 - 31) of up to approx. 165. A silicon dioxide gel of low specific gravity may be present in admixture with the aluminum silicate. The overall oil absorption value for the dispersed, solid components in the toothpaste (which is obtained by multiplying the oil absorption value for each component by the percentage content of the component in the toothpaste) is preferably 40 - 60. It has been shown that such toothpastes has excellent: rheological properties. They are very full, can be easily squeezed out of a normal toothpaste tube, retain a shiny appearance without visible matting or the formation of a dull skin for a long time after being squeezed out of the toothpaste tube, have a desired short consistency and are not undesirable thread-like or grain-like, can be easily processed in automated tube-filling equipment, have good tooth cleaning and polishing properties and give a pleasing mouthfeel, and they have good clarity (for toothpastes of the transparent type). In contrast to those in US patent document no.

3,689,637 described products have the toothpaste according to the invention

such properties even in the absence of a polyethylene glycol with an average molecular weight of over approx. 800. It will appear from the . examples below that polyethylene glycol can be completely looped or that a polyethylene glycol with a lower molecular weight can be used.

The toothpastes according to the invention can be prepared so that they are particularly suitable for use in tropical climates. The components are resistant to biological and chemical attack.

The sodium aluminum silicate abrasive preferably has a refractive index of 1.44 - 1.47 and contains at least approx. 70% silicon dioxide, up to approx. 10% aluminum oxide, preferably at least approx. 0.5% aluminum oxide, up to approx. 20% moisture by weight and up to approx.

10% by weight sodium oxide. The preferred moisture content is 10 - 20% by weight, measured by loss of moisture on ignition at 1000°C, and a typical sodium oxide content is 5 - 10% by weight. As an abrasive, an aluminum silicate can be used with an oil absorption value of 150 -

160 g/100 g and with a volume weight in a slightly compacted state of below

0.2 g/cm 3 . However, a better cleaning power is obtained when the aluminum silicate has an oil absorption value of less than approx. 130 g/100 g, e.g. about. 75 - 115 g/100 g, and a volume weight in slightly compacted

o 3 '3

condition of over approx. 0.25 g/cm, e.g. 0.3 - 0.4 g/cm . Materials in which the molar ratio SiC^A^O^ is at least approx. 45:1, are particularly suitable. Aluminum silicates of other alkali metals, e.g. K,

or of alkaline earth metals, e.g. Ca or Ba, can completely or partially replace the sodium aluminum silicate. Aluminum silicates of two or more of the aforementioned metals can also be used.

The total relative amount of the aluminosilicate abrasive constitutes 1 - 50% of the toothpaste, preferably 5 - 40%, e.g. 16 - 30%. ,

The silicon dioxide gel with a low volumetric weight (ie dehydrated silicon dioxide hydrogel) is typically a material with a particle size of 1 - 5 µm, e.g. 3-4 ym; and with a volume weight (after centrifugation) of well below 0.25 g/cm, usually 0.10 - 0.20, e.g. 0.15, g/cm . It may be a silicon dioxide aerogel. Its oil absorption value is at least approx. 300, and usually under approx. 350, e.g. 305 - 315, kg/100 kg, and its surface area is below approx. 350, usually well over 100, £„ex. 250 - 320, m/g. The product sold under the trademark "Syloid" 244 is typical of this type of material. When used, it is present in an amount less than the amount of aluminosilicate, and preferably in an amount of up to about 10% by weight of the toothpaste, e.g. 1-9% by weight, as 6 -

9% by weight.

The carrier material in the toothpaste mainly consists of

a wetting agent, such as glycerol or sorbitol, usually mixed with water. Overall, it is advantageous that the relative amount of these liquids in the toothpaste amounts to 40 - 90%, preferably 60 - 80%, and preferably 65 - 75%. Sorbitol which is usually present in the form

of solutions in water, and typically at a concentration of 70% in water, is considered a liquid for the present purpose. Additional water beyond the amount present if sorbitol is used is preferably present in an amount of 5 - 35%, preferably 15 -

20% of the total liquids.

As indicated above, a polyethylene glycol may be present in the carrier material. These materials are well known in the art.

They typically consist of mixtures of polymers with different degrees of polymerization. The curve showing the distribution of the molecular weights (e.g. the curve obtained by plotting the degree of polymerization in relation to the weight percentage), is typically a smooth "bell"-shaped distribution curve. Such materials are described in the book "Carbowax Polyethylene Glycols." F-4 772E, published by Union Carbide Chemicals Company. The materials with an average molecular weight of 200 - 600 are clear liquids at 25° C (although the material with an average molecular weight of 600 begins to solidify into a soft, wax-like material at about 25° C), while the materials with a average molecular weight of 1000 - 20,000 are white, wax-like solids. Particularly good results are obtained when the polyethylene glycol's average molecular weight is approx. 600. The relative amount of polyethylene glycol is usually below approx. 10%, e.g. 1 - 8%, preferably 3 - 7.5%, of the toothpaste.

The toothpaste can also contain a surfactant, e.g. to achieve an increased prophylactic effect, to facilitate the attainment of a uniform and complete dispersion of the present toothpastes in the oral cavity and to make the present toothpastes cosmetically more acceptable. The organic surface-active agent can be anion-active, non-ionic, ampholytic or cation-active, and it is preferred as surface-active agent to use a cleansing material which makes the toothpaste cleansing and foaming. As suitable examples of such detergent-active materials, mention can be made of water-soluble salts of higher fatty acid monoglyceride monosulfates such as the sodium salt of the monosulfated monoglyceride of hydrogenated coconut oil fatty acids, higher alkyl sulfates such as sodium lauryl sulfate, alkyl <1>aryl<y>lsulfonates such as sodium dodecylbenzene sulfonate, higher alkyl sulfo -acetates, higher fatty acid esters of 1,2-hydroxypropanesulfonates and the essentially saturated higher aliphatic acylamides of lower allphatic aminocarboxylic acids, such as those having 12 - 16 carbon atoms in the fatty acid radical, the alkyl radical or the acyl radical etc. Examples of the latter amides are N- lauroylsarcosine and the sodium, potassium and ethanolamine salts of N-lauroyl-, N-myristoyl- or N-palmitoylsarcosine which should be substantially free of soaps or similar higher fatty acid materials which tend to greatly impair the action of these compounds. It is particularly advantageous in the present toothpastes to use these sarcosine compounds because they provide a long-lasting and clear effect in terms of inhibiting acid formation in the oral cavity due to the breakdown of carbohydrates, in addition to the fact that they provide a certain reduction in the solubility of tooth enamel in acidic solutions.

Of other particularly suitable surface-active materials, non-ionic surface-active materials, such as condensates of sorbitan monostearate, can be mentioned. with approx. 60 mol eth.yleno.xyd and.condensates of eth.yleno.xyd and.condensates of eth.yleno.xyd with propylene oxide condensates of propylene glycol ("Pluronics" Y, and amphoteric materials such as quaternary imidazole derivatives commercially available under the trademark "Miranol", such as "Miranol" C2M. Cationic surfactant germicidal and antibacterial compounds, such as di-isobutylphenoxyethoxyethyldimethyl-benzylammonium chloride, benzyldimethylstearyammonium chloride, tertiary amines with one fatty alkyl group of 12 - 18 carbon atoms and two (poly)-oxyethylene groups attached to the nitrogen atom (typically containing a total number of 2 - 50 ethanoxy groups per molecule) and salts thereof with acids, and compounds with the structural formula

<h>vori' R is a fatty alkyl group containing 12 - 18 carbon atoms and il, y and z together are 'a number of 3 or, higher, and furthermore salts thereof with organic mineral acids, can also' be used.

It is preferred that the total amount of surface-active agent constitutes 0.05-5% by weight, preferably 1-3% by weight, of the toothpaste.

Various other materials can be incorporated into the toothpaste according to the invention. Examples of these include coloring materials or whitening agents, preservatives, silicones, chlorophyll compounds, ammonia-containing materials such as urea, diammonium phosphate and mixtures thereof, and other ingredients. Each of these additives can typically be incorporated into the present toothpastes in an amount of up to approx. 5%.

The toothpaste may also contain antibacterial agents

an amount of 0.01 - 5%. Typical examples of such agents are guanidines, biguanides and amines, such as

N 1 -(4~chlorobenzyl)-N 5-2,4-(dichlorobenzyl)-biguanide, p-chlorophenylbiguanide, 4-chlorobenzhydrylbiguanide, 4-chlorobenzhydrylguanylurea, N-3-lauroxypropyl-N 5~p-chlorobenzylbiguanide , 1,6-di-p-chlorophenyl-biguanidohexane, 1-(lauryldimethylammonium)-8-(p-chlorobenzyldimethyl-ammonium)-octanedichloride, 5 , 6-dichloro-2-guanidinobenzimidazole, N-<1>"-p- chlorophenyl-N-laurylbiguanide, 5-amino-1,3-bis-(2-ethylhexyl)-5-methylhexahydropyrimidine and their non-toxic acid addition salts.

Suitable flavoring agents or sweeteners can be used to add flavor to the present toothpastes. As examples of suitable flavourings, the flavoring oils can be mentioned, e.g. green mint oil, peppermint oil, wintergreen oil, sassafras oil, clove oil, sage oil, eucalyptus oil, marjoram oil, cinnamon oil, lemon oil and orange oil, and also methyl salicylate. Examples of suitable sweeteners are sucrose, lactose, maltose, sorbitol, sodium cyclamate and saccharin. The total amount of flavoring agent and sweetener can advantageously amount to 0.01 - 5% or more of the present toothpastes.

The toothpastes according to the invention can also advantageously contain a fluorine-containing compound with a beneficial effect on the care°9hygiene of the oral cavity, e.g. to reduce enamel solubility in acids and to protect the teeth against decay. Examples of these compounds include sodium fluoride. divalent stannous fluoride, potassium fluoride, potassium stannous fluoride (SnF2«KF), sodium hexafluorostannate, divalent stannous chlorofluoride, sodium fluorozirconate and sodium monofluorophosphate. These materials which decompose or emit fluorine-containing ions in water can advantageously be present in an effective, but non-toxic, amount of usually 0.01 - 1% by weight, based on the water-soluble fluorine content of the compounds.

Other abrasives may be present in the toothpaste. If these have a refractive index which is significantly different from the refractive index of the carrier material, it is preferred that they are present in such a form and in such an amount that the toothpaste does not become opaque or opaque. This makes it possible to achieve different visual, aesthetic effects. Thus, such abrasives can be used in the form of the known visible, palpable agglomerates of the finely divided abrasive powders with microscopic size (eg a particle diameter of 2 - 20 µm), the agglomerates having a diameter of e.g. 20 0 - 800 ym, are present in smaller amounts, e.g. 1 - 5%, so that the toothpaste has a spotted appearance and the spots can be seen in the otherwise transparent toothpaste. The specks will break down into invisible, imperceptible particles in the mouth when they are exposed to pressure from and the movement of the toothbrush. The added abrasives can also be present in an amount well below 5%, e.g. 0.5 or 1%, together with a material that gives a visible effect, such as iridescent particles that can also give a grinding or cleaning effect, like this. that a toothpaste with a sparkling1 appearance is obtained.

In the description and patent claims, all relative amounts are based on weight if nothing else is stated.

Example 1-9

Toothpastes were prepared using the recipes given in Table I. In each case, the toothpaste was prepared by adding the solid ingredients to a mixture of the liquids, after which the mixture was deaerated under vacuum and chloroform was added while the toothpaste mixture was not deaerated before the mixture was filled into ordinary squeezable toothpaste tubes. These were stored at room temperature for several days before the toothpaste was examined.

The toothpaste could easily be squeezed out in the form of a ribbon from the toothpaste tube. It had good volume and did not lead to thread formation. After a strip of the toothpaste had been squeezed out, there was little or no tendency for the toothpaste to continue to ooze out of the tube after the squeezing pressure had been released. The toothpaste could easily be processed in equipment for automatic filling of tubes and where the toothpaste was extruded (periodically) in squeezable tubes through a nozzle and where it was desirable that there should be no dripping or protruding threads from the nozzle after a tube had been filled and before the next tube was filled. A strip of the toothpaste squeezed out of the tube retained its clear, shiny appearance for a considerable time.

After storage for 9 weeks at a temperature of 49°C in a toothpaste tube, the toothpaste retained its desirable properties. Its bulk and viscosity increased, but >it could still be squeezed out easily. The recipe according to examples 2 - 9 is particularly suitable for maintaining good squeezed-out toothpaste bands and for avoiding plug formation - See at the neck of the tube during storage.

It appears that in examples 4 and 5 large amounts of sodium aluminum silicate are used without a thickening agent consisting of silicon dioxide gel with a low specific gravity.

Footnote is for Table I

(a) .. Natri.maalumini.uinsi.lik.ate had the following empirical sant™

(composition: approx. 72% silicon dioxide, approx. 8% aluminum oxide, approx.

7% sodium oxide and approx. 12% water (combustion loss at 1000° C)• It had a surface area of approx. 110. aa'/ g, a particle size of approx. 4 ym (since the particles were in the form of aggregates of a material with a single particle size of 35 nm), an oil absorption value of approx. 160 g/100 g and a pH (for a 4% slurry in water) of approx. 10.5. (b) Sodium aluminum silicate is sold under the trade name "Zeo 49" and had the following approximate analysis: 78% silicon dioxide, 1% aluminum oxide, 10.6% water (combustion loss) and 10.3% sodium oxide (calculated from the difference). Its bulk density was 0.3 - 0.4 g/cm 3 , its surface area (B.E.T.) below 300 m 2 /g and its oil absorption value 80 - 110 g/100 g. Its refractive index was 1.450 - 1.465 and its pH (in a 5 % aqueous slurry) 6.0 - 7.5. (e) The polyethylene glycol had an average molecular weight of approx. 600 (e.g., 570 - 630 corresponding to an average degree of polymerization of 13 - 14), its freezing point corresponded to approximately room temperature (20 - 25° C.), and its molecular weight distribution was as follows: "P..G." means degree of polymerization, ie; number of ethylene oxide units in the molecule, and "%" means % by weight. The figures in the above table are based on the curve for "Polymer Distribution in Carbowax Polyethylene Glycols..." in the book "Carbowax Polyethylene Glycols" F-4772E, published by Union Carbide Chemicals Company. (f) The polyethylene glycol had an average molecular weight of approx. 1500. (g) The polyethylene glycol had an average molecular weight of approx. 4000. (c) 70% sorbitol denotes a 70:30 mixture of sorbitol and water. (d). The dye solution was a mixture of 1% solution of "F, D and C" dyes, e.g. red No. 2 and yellow No. 6. (k)_ The specks were of a size visible to the naked eye (with a particle diameter of 250 - 420 µm) and consisted of a mixture of 80% polyethylene with a molecular weight of 1500 (softening point 102° C) and 20% of a tooth polishing agent consisting of zirconium silicate and with a fine particle size. (h) The aluminum oxide was α-aluminium oxide in the form of flakes, as described in US Patent No. 3,121,623, and more specifically flakes with an average particle diameter by weight of approx. 4 etc. (i) . The iridescent flakes consisted of mica flakes which were coated with titanium dioxide and which had a size of 15 - 40 um. The thickness of the flakes was approx. 0.7 ym, the titanium dioxide coatings (on both sides of each flake) consisted of titanium dioxide in the anatase form, and the flakes consisted of approx.

20% titanium dioxide in anatase form and 80% mica.

According to the invention, the aluminum silicate (as in examples 4 and 5) can also be completely or partially replaced with a silicon dioxide gel (or a silicon dioxide aluminum oxide gel) with an intermediate specific gravity, such as "Syloid" 74 (oil absorption value approx. 200 g/100 g), or with hay. specific gravity, such as "Syloid" 63 (oil absorption value approx. 60 g/100 g).

According to the invention, the silicon dioxide gel with a low specific gravity can also be completely or partially replaced with precipitated silicon dioxide or precipitated silicon dioxide-aluminum oxide. It is well known in the relevant state of the art that both silicon dioxide gel and precipitated silicon dioxide are usually prepared by adding an acid, e.g. sulfuric acid, to a solution of a soluble silicate, e.g. an aqueous sodium silicate solution, see e.g. Encyclopedia of Chemical Technology (Kirk-Othmer), 2nd Edition, Volume 18, pp. 61 - 62. A suitable type of precipitated silicon dioxide or precipitated silicon dioxide-aluminum oxide is commercially available under the trade name "Zeosyl" 200 XP and contains approx. 90%, e.g. 89 92%, silicon dioxide,

about. 1%, e.g. 1 - 1.2%, aluminum oxide, approx. 5% water (e.g. published data specify a maximum loss of 7% when heated at 105° C) and at most approx. 3% Na2^ 0^ as contamination, and has a particle size (in an aggregated state) of approx. 2 ym, a specific gravity at 25° C of 2.0, a bulk density of 0.12 - 0.16 g/cm'<3>, an oil absorption ion value of 200 - 230/100. g, a pH (for a 5% suspension in water) of approx. 7, e.g. 6.5 - 7.5, and a refractive index of approx. 1.45, e.g.

145 - 1.46. This material can be used directly to completely or partially replace the sillcitundio^cydgel with a low specific gravity indicated in any of the above examples 1-9. The precipitated silicon dioxide or the precipitated silicon dioxide aluminum oxide is used as a thickening agent. The silicon dioxide content in the thickener is at least approx. 70%.

Claims (7)

1. Toothpaste comprising a carrier material comprising a humectant, and a tooth abrasive dispersed in the carrier material and which mainly consists of material with a particle size of 2 - 20 µm and with a silicon dioxide content of at least approx. 70% and which has an amorphous X-ray structure, characterized by the fact that it is free of rubber or another thickener soluble in the carrier material, and that the main abrasive consists of an alkali metal or alkaline earth metal aluminum silicate with an oil absorption value of up to approx. 165. 2. Toothpaste according to claim 1, characterized in that the dispersed, solid components in the toothpaste have a total oil absorption value of 40 - 60, and that the main abrasive consists of sodium aluminum silicate. 3. Toothpaste according to claim 1 or 2, characterized in that the main abrasive has. an oil absorption value of 75 - 115 g/100 g. 4. Toothpaste according to claim 2 or 3, characterized in that it also contains particles of a silicon dioxide-containing thickener which consists of a silicon dioxide gel, a silicon dioxide aluminum oxide gel, precipitated silicon dioxide or precipitated silicon dioxide aluminum oxide, and which has a volume weight of 0.1 - 0.2 . g/cm3. 5. Toothpaste according to claim 4, characterized in that the silicon dioxide-containing thickener has a particle size of 1 - 5 µm, 6. Toothpaste according to claims 1-5, characterized in that it contains sodium aluminum silicate which is essentially the only abrasive. 7. Toothpaste according to claims 1-6, characterized in that it contains 1 - 10% polyethylene glycol with an average molecular weight of approx. 600.