Drug – bio-affecting and body treating compositions – Dentifrices – Fluorine or fluorine compound containing
Patent
1996-07-31
1999-08-03
Mach, D. Margaret M.
Drug, bio-affecting and body treating compositions
Dentifrices
Fluorine or fluorine compound containing
424 49, 423335, 423339, A61K 716, A61K 718, C01B 3312
Patent
active
059321911
DESCRIPTION:
BRIEF SUMMARY
This application is a 371 of PCT/FR94/01543, filed Dec. 28, 1994.
The present invention relates to silicas, in particular precipitated silicas, which can be used in particular as abrasive agents in toothpaste compositions.
The invention also relates to a process for their preparation and to the toothpaste compositions containing them.
A great many toothpaste compositions have been developed and marketed for several years now.
It is known that toothpaste formulations may contain various components, in particular water, a wetting agent (for example glycerol, sorbitol, xylitol or polyethylene glycol, etc.), a thickener (for example xanthan gum), a source of fluoride (usually sodium fluoride or sodium monofluorophosphate (anti-tooth-decay agent)), a colorant, a flavouring, a sweetener, a fragrance, a preserving agent, a surfactant and/or a therapeutic additive, etc.
They generally also contain an abrasive agent which must, by its mechanical action, remove dental plaque while at the same time not subjecting the teeth themselves to unacceptable abrasion.
Among the abrasive agents usually employed, mention may be made of calcium carbonates and phosphates, sodium metaphosphates, aluminas and, in recent years, silicas.
However, the silicas of the prior art used as abrasive agents in toothpaste compositions are not always of desirable refractive index or porosity.
The aim of the present invention is, in particular, to provide novel silicas of low specific surface, which are, at the same time, of high abrasive power and of relatively low refractive index and oil absorption, these silicas furthermore being compatible with organoamine compounds.
The invention also relates to a process for the preparation of the said silicas and to their use in toothpaste compositions.
Thus, one of the subjects of the invention is a silica, preferably a precipitated silica, which can be used in particular as an abrasive agent in toothpaste compositions, this silica having: amines, of at least 50%.
In the present account, the BET specific surface is determined according to the Brunauer-Emmett-Teller method described in "The Journal of the American Chemical Society", vol. 60, page 309, February 1938 and corresponding to ISO standard 5794/1 (Annex D).
The CTAB specific surface is the external surface determined according to NFT standard 45-007 (November 1987) (5.12).
The RDA ("Radioactive Dentine Abrasion") abrasiveness is measured according to the method described by J. J. Hefferren in "Journal of Dental Research", vol 55(4), page 563, 1976.
According to this method, human teeth irradiated with a flow of neutrons are subjected to a certain amount of mechanical brushing; the abrasive index of the toothpaste tested corresponds to the .sup.32 P radioactivity emanating from the dentine. A suspension containing 10 grams of calcium pyrophosphate in 50 ml of aqueous 0.5% sodium carboxymethyl cellulose solution is chosen as reference, the RDA of this reference being arbitrarily set at 100. The silica whose RDA it is desired to determine is suspended like the calcium pyrophosphate and subjected to the same mechanical brushing.
The refractive index of the silica in sorbitol is that of the most transparent suspension (and thus that of maximum transmission) of this silica in various water-sorbitol solutions, this transparency being determined by transmission at 589 mm with a spectrophotometer. Each suspension is obtained by dispersion of 1 gram of silica in 19 grams of water-sorbitol solution, followed by de-aeration under gentle vacuum before reading the transmission (reading taken with, as reference product, the silica-free water-sorbitol solution) on the spectrophotometer and the refractive index on a refractometer.
The DOP oil absorption is determined according to ISO standard 787/5 using dioctyl phthalate.
The average size of the silica particles by weight, D.sub.50, is determined using a Sympatec Helos machine. This machine applies the principle of Fraunhoffer diffraction and uses a low-power He/Ne laser. The sample is predispersed by applicati
REFERENCES:
patent: 4243428 (1981-01-01), Donnet
patent: 4312845 (1982-01-01), Wason
patent: 4581217 (1986-04-01), Shinpo
patent: 5225177 (1993-07-01), Wason
patent: 5342598 (1994-08-01), Persello
patent: 5447704 (1995-09-01), Alddcroft
patent: 5582816 (1996-12-01), Mandanas
patent: 5603920 (1997-02-01), Rice
patent: 5624652 (1997-04-01), Aldcroft
patent: 5651958 (1997-07-01), Rice
Chevallier Yvonick
Dromard Adrien
M. Mach D. Margaret
Rhone-Poulenc Chimie
Seugnet Jean-Louis
Wood John Daniel
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