SK402001A3 - Liquid tooth cleaning agents - Google Patents

Abstract

Liquid tooth cleaning agents containing the following ingredients: 5-15 wt. % precipitated silicic acid with an average particle size of 8-14 mu m and a specific surface of 40-75M2/g (BET) in addition to a low thickening characteristic, 20-55 wt. % glycerin, sorbite or a mixture thereof, and 0.3-1.0 wt. % xanthan gum as a binding agent, whereby the viscosity thereof ranges from 10-100 Pa. The inventive tooth cleaning agents have a flow point of at least 10 Pa yet begin to flow easily at a low shear force e.g. when pressure is exerted on a flexible dispenser.

Description

Technical field

FIELD OF THE INVENTION The present invention relates to liquid dentifrice compositions containing polishes, humectants, binders and water which have improved viscosity stability and improved rheological behavior over conventional liquid dentifrices of this type and are therefore particularly advantageous for use and dispensing from flexible plastic bottles. .

BACKGROUND OF THE INVENTION

According to the prior art, for example according to DE 42 22 739 A1, EP 543 442 B1 or US 5,178,869, liquid dentifrice compositions are known which contain polishing agents, for example coagulated silicas, humectants, for example glycerin or sorbitol, and binders, for example xanthan gum . A problem with such dentifrices is the stable dispersion of the rinse aid, which must not be deposited on the bottom during storage without deteriorating flowability and the products can no longer be easily extruded and dispensed from plastic bottles. Although the composition is to flow well from the dispenser under the action of self-weight shear forces, at rest, for example on a toothbrush, the composition should be so dense that it does not flow or only flows very slowly between the bristles of the toothbrush.

While, for example, EP 543 442 B1 proposes an extremely low polyol content, it requires US 5,178,869 to influence the theological behavior in the desired sense of a flow limit of 1 to 60 Pa (20 ° C). In DE 42 22 739 A1, viscosity stability is achieved with certain additives of surfactants, hydrocolloids and polyglycols, but it is required that the dental care composition, when applied to the toothbrush, flow between the bristles and have a viscosity of from 2 to 10 Pa.s.

In the meantime, it has been found that for the use of such dental care compositions it is preferred that the viscosity is in the range of 10 to 100 Pa.s (20 ° C), thixotropic

However, the product meets certain limit values with respect to the lower and upper flow limits.

The upper creep limit (Fh) is denoted by the shear force value T (Pa) obtained by extrapolating the viscosity curve ascending (with increasing shear force) [for D (shear rate) = 0] and as the lower creep limit (F _d ) the extrapolation value of the shear force T (Pa) in the downward measurement [for D = 0], the so-called Casson approximation is used as extrapolation aid.

By increasing the binder content it was possible to increase the creep limits and to slow the flow of the product between the toothbrush bristles with an otherwise constant composition, but at the same time the storage viscosity increased up to the loss of fluidity. Reducing the binder content avoided additional gelling but reduced the very resting viscosity and creep limit so that the paste flowed quickly between the bristles. Similar effects were also observed when increasing or decreasing the proportion of rinse aid.

The invention now discloses measures to maintain these theological parameters.

The essence of the invention is from 20 to 55 wt. from 0.3 to 1.0 wt

The present invention relates to liquid dentifrice compositions comprising polishing agents, humectants, binders and water comprising: from 5 to 15 wt. coagulated silicic acid with a mean particle size of from 8 to 14 µm, a specific surface area of from 40 to 75 m ² / g (BET) and a low thickening effect, glycerin, sorbitol or a mixture thereof, xanthan gum as a binder and having a viscosity measured at 20 ° C (Brookfield RVT, 4 rpm, spindle 4 to 50 Pa.s, spindle 5 to 100 Pa.s), ranging from 10 to 100 Pa.with a lower creep limit (F _d ) of at least 10 Pa (20 ° C) and whose upper creep limit (F _h ) is not more than 2 F _d (F _d > 10 Pa, F _h <2 F _d ). By means of these creep limits, the paste starts to flow under a shear force of more than 10 Pa, for example by squeezing the dosing container, and is relatively highly viscous at rest when it is at the toothbrush.

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The quality of coagulated silicic acid, which is contained as a polishing component, has been shown to have a decisive influence on rheology. For example, it is not sufficient to use a marketed product such as Sident 10 having a specific surface area of 80 m ² / g (BET) and an average grain size of 6 µm, since such silicic acid still has a considerable thickening effect in the aqueous system. According to the invention, the mean particle size must be from 8 to 14 µm and the specific surface area must be from 40 to 75 m ² / g (BET).

The thickening effect of a standard dispersion composed of 20 wt. % silicic acid, 40 wt. % glycerin, 37 wt. % water, 2 wt. % polyethylene glycol 400 and 1 wt. The carboxymethylcellulose should be less than 5 Pa.s (20 ° C, Brookfield, RVT spindles 1 and 5). The corresponding value for Sident®12 is 15.5 Pa.s. Sident®8 (Degussa) and Sorbosil® AC 39 (Crosfield Chemicals) as well as the product designated RP-LA 2981 (Rhône Poulenc) are suitable as commercially available silicas with the features of the invention. The thickening power for Sident®8 is approximately 1.8 Pa.s and for Sorbosil® AC 39 is approximately 1.6 Pa.s (20 ° C, Brookfield, RVT spindle 1 or 5 respectively).

The dentifrice compositions of the present invention may contain, in addition to the aforementioned non-thickening coagulated silicas, other polishing ingredients in amounts up to 5% by weight. Such components may be, for example, aluminum oxides, calcium phosphate dihydrate, calcium carbonate, dicalcium phosphate or other polishing components, which themselves have no remarkable thickening properties. Thickening silicas should not be present or should only be present in amounts less than 1% by weight.

The humectant according to the invention comprises glycerine, sorbitol or a mixture of glycerin and sorbitol in an amount of from 20 to 55% by weight. The content of glycerin and sorbitol in a weight ratio of 6: 4 to 4: 6 is preferred. In addition, they may be in minor amounts of up to 5% by weight. also included other known diols or polyols or polyethylene glycols. Such other humectants are, for example, 1,2-propylene glycol, xylitol and polyethylene glycols having a molar mass of from 200 to 10,000.

More preferably, the binder consists exclusively of xanthan gum, but other binders may also be present in amounts up to 0.5% by weight. Such additional binders are, for example, carrageenan, trangant, guar, starch, starch cellulose ether, agar-4, agar-4. Agar, pectin, polyvinyl alcohol, polyvinylpyrrolidone and polyethylene glycols having a molecular weight greater than 10,000.

In addition, the dentifrice compositions of the invention may contain conventional adjuvants and additives in amounts up to 10% by weight.

Liquid dentifrices can, for example, improve their organoleptic properties by adding aromatic oils or sweeteners. All natural and synthetic flavors common to mouth and tooth care products can be used as aromatic oils. Natural flavorings may be present in the form of natural essential oils isolated from the drug or as individual constituents isolated from them.

Suitable flavorings are, for example, peppermint oil, crisp mint oil, eucalyptus oil, anise oil, fennel oil, caraway oil, menthent acetate, cinnamic aldehyde, anethole, vanillin, thymol, as well as mixtures of these components.

Suitable sweeteners are, for example, sodium saccharin, sodium cyclamate, sucrose, lactose, maltose, fructose.

Other common excipients and toothpaste ingredients are:

- preservatives and antimicrobials, for example methyl, ethyl or propyl p-hydroxybenzoic acid, sodium sorbate, sodium benzoate, bromochlorophene, triclozane, phenyl-salicylic acid ester, biguanides such as chlorhexidine and peroxides

surfactants, more preferably anionic, amphionic, amphoteric, nonionic surfactants or combinations of several different surfactants

- solvents and solubilizers, for example low monohydric or polyhydric alcohols or ethers, for example ethanol, 1,2-propylene glycol, diethylene glycol or butyldiglycol

fluorine compounds such as sodium fluoride, zinc fluoride, sodium monofluorophosphate, aminofluoride and others

pigments such as titanium dioxide

- dyes

- buffering agents, for example, primary, secondary or tertiary alkaline phosphates or citric acid / sodium citrate

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- healing or inflammatory suppressants, for example allantoin, urea, azulene, camomile, acetylsalicylic acid derivatives or rodanide

vitamins such as ascorbic acid, retinol or tocopherol

mineral salts such as salts of manganese, zinc or magnesium

The following examples are intended to illustrate the invention in more detail.

DETAILED DESCRIPTION OF THE INVENTION

Example

1 2 3 4 5 6 IN Sident® 8 12 12 12 12 12 12 - Šiďéňt®12 - - - - - - 12 glycerin 28 28 28 28 28 28 28 sorbitol 21 21 21 21 21 21 21 KeltroA F 0.36 0.4 0.45 0.6 0.8 1.0 0.26 hydroxypropyl guar 0.04 - - - - - - sodium fluoride 0.33 0.33 0.33 0.33 0.33 0.33 0.33 sodium saccharinate 0.2 0.2 0.2 0.2 0.2 0.2 0.2 laury Sodium sulfate 1.44 1.44 1.44 1.44 1.44 1.44 1.44 Ta g a t® S 0.5 0.5 0.5 0.5 0.5 0.5 0.5 aroma 1.0 1.0 1.0 1.0 1.0 1.0 1.0 ethanol 2.0 2.0 2.0 2.0 2.0 2.0 2.0 Water to 100 to 100 to 100 to 100 to 100 to 100 to 100 viscosity ¹ (Pa.s) 22 23 24 50 63 94 10 F _h (after 10 days) [Pa] 24 21 28 35 45 63 30 F _d (after 10 days) [Pa] 15 14 18 21 30 43 8 run-in time (min) 6.6 4.9 > 15 > 15 > 15 > 15 1.04

¹ Measurement of the viscosity was performed using a Brookfield rotational viscometer, model RTV, spindle 4 or 5 (for Example 5 and 6) at 20 ° C and a speed of 4 rpm ^first

The following commercial products were used:

Ttt tt tt tt tt tt tt tt tt tt tt tt tt tt tt tt tt tt

Sident 8:

Sident®12 DS:

Keltrol®F:

Tagat®S:

amorphous synthetic silica specific surface area (according to BET): 60 m ² / g mean particle size of the agglomerate: 10 pm supplier: DEGUSSA AG coagulated silica specific surface area (according to BET): 80 m ² / g mean particle size of agglomerate: 6 pm supplier : DEGUSSA AG xanthan gum from KELCO, Brussels polyoxyethylene- (20) -glycerin monostearate from Goldschmidt, Essen

Changes in creep limits (Fh, F _d , [Pa] when stored at 20 ° C after n days)

recipe no. 1 2 3 4 n F _h F _d F _h F _d fh fd fh F _d 0 (immediately) 24 16 18 14 26 18 30 22 1 - - 20 14 27 18 - - 2 - - - - 26 18 - - 3 23 15 - - 27 18 35 21 4 23 15 - - 28 18 35 21 5 23 15 - - 28 18 - - 6 23 15 20 14 28 18 - - 7 24 15 20 14 28 18 - - 8 24 15 21 14 27 18 35 21 g 24 15 21 14 27 18 35 21 10 24 15 21 14 28 18 35 21

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recipe no. 5 6 IN n F _h F _d F _h F _d F _h fd 0 (immediately) 41 30 58 43 16 8 1 40 28 62 43 20 9 2 43 31 - - - - 3 45 29 - - - - 4 - - - - 25 8 5 - - 62 43 - - 6 - - 62 41 - - 7 - - - - 27 8 8 43 30 - - - - 9 46 30 - - - - 10 45 30 63 43 30 8

A

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PATENT CLAIMS

Claims (4)

PATENT CLAIMS Liquid dentifrice compositions containing polishes, humectants, binders and water, comprising: - from 5 to 15 wt. coagulated silicic acid with a mean particle size of 8 to 14 µm, a specific surface area of 40 to 75 m ² / g (BET) and a low thickening effect, from 20 to 55 wt. glycerin, sorbitol or mixtures thereof, from 0.3 to 1.0 wt. xanthan gum as a binder and that the viscosity, measured at 20 ° C (measured with a Brookfield viscosimeter of the RVT type), is in the range of 10 to 100 Pa.and their lower flow limit (F _d ) is at least 10 Pa (20 ° C) and the upper creep limit (F _h ) is not greater than 2F _d . 2. A liquid dentifrice composition according to claim 1, wherein the humectant comprises a mixture of sorbitol and glycerin in a weight ratio of 6: 4 to 4: 6. The liquid dentifrice composition of any one of claims 1 or 2, wherein the polishing agent is selected from the group of commercial products Sident®8 (Degussa) and Sorbosil® AC39. Liquid dentifrice compositions according to any one of claims 1 to 3, characterized in that they contain conventional adjuvants and additives from the group of flavorings, sweeteners, preservatives, surfactants, solvents, fluorine compounds, pigments, dyes, buffers. , wound healing substances, vitamins and mineral salts in amounts up to a total of 10% by weight.