JPH0534329B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to an oral composition such as a toothpaste containing silica and modified aluminum hydroxide obtained by treating aluminum hydroxide with an acid or its salt as an abrasive. More specifically, the present invention relates to an oral composition that is comfortable to use and has suppressed bitterness and astringency of silica. BACKGROUND ART Conventionally, gelling silica, precipitated silica, silica xerogel, silica aerogel, and other abrasive silicas have been incorporated into oral compositions such as toothpastes. However, since silica generally has a unique bitterness and astringency, when silica is blended into an oral composition, the bitterness and astringency deteriorate the feel of the composition. If 3% (by weight, the same applies hereinafter) or more of the composition is added, the problem becomes significant. especially,
This tendency becomes more pronounced when silica with a particle size of 1 μm or less is used, and in this case, even at a blending amount of about 2%, the user will feel uncomfortable when using the product.
In addition, as a silica-based abrasive, the particle size of the primary particles is
Even when using particles with a particle size of 500 mμ or more and a secondary particle size of 1 to 30 μm, this product has a relatively weak bitterness and astringency, but if it is blended in an amount of 5% or more, a strange feeling still occurs. To this end, conventionally, additives such as gelatin and dialkynolamide, or flavoring materials such as cloves are added to oral compositions containing silica, such as toothpaste, to reduce the bitterness and astringency of silica. Taste masking has been attempted, but the masking effect is not sufficient, and there are problems in that when a large amount of gelatin or dialkynolamide is added, the oral composition becomes unpleasant to use and browns during storage. Therefore, there has been a desire for an oral composition that effectively suppresses the bitterness and astringency of silica and has a good feeling of use. Features of the Invention In view of the above circumstances, the present inventors have conducted intensive research on suppressing the bitterness and astringency of silica blended into oral compositions such as toothpaste, and have found that aluminum hydroxide is used as an abrasive. In an oral composition using modified aluminum hydroxide obtained by treating with an acid or its salt, silica is blended in an amount of 3% by weight based on the total composition, and the amount of the modified aluminum hydroxide is 5 of the amount of silica with a particle size of 1μ or more
The amount of silica is more than twice the weight and the particle size exceeds 1μ.
It was discovered that when the amount of silica is 0.5 times the weight or more, the bitterness and astringency can be effectively suppressed even if the amount of silica is large, and an oral composition with a good feeling of use can be obtained. This is what we have come to do. The present invention will be explained in more detail below. Structure of the Invention The oral composition according to the present invention is a composition containing silica and modified aluminum hydroxide obtained by treating aluminum hydroxide with an acid or a salt thereof. The modified aluminum hydroxide used in the present invention is obtained by treating aluminum hydroxide with an acid or its salt. In this case, there is no particular restriction on the aluminum hydroxide used for modification, and a normal method can be used. A commercially available product can be used. Note that the average particle size of the aluminum hydroxide used is preferably 1 to 30 microns, particularly 3 to 20 microns, from the viewpoint of processability. In this case, it is preferable to use aluminum hydroxide that has been pulverized into the desired shape and particle size using a ball mill, jet mill, rotary impact pulverizer, etc., and the abrasive power of the resulting modified aluminum hydroxide can be varied in various ways. can be adjusted to Moreover, as the acid or salt used for modifying the aluminum hydroxide, inorganic acids, organic acids, and salts thereof can be used. Examples of inorganic acids and their salts include phosphoric acid, sulfuric acid, hydrochloric acid, and their salts, and examples of organic acids and their salts include acetic acid, oxalic acid, tartaric acid, succinic acid, and their salts. Among these, phosphoric acid and its salts are preferably used, and the pH of the 10% water slurry of such modified aluminum hydroxide is usually about 5 to 8, and the pH of unmodified aluminum hydroxide is about 10%.
% water slurry is considerably lower than the normal pH of around 9, the composition will not be prepared to a high pH, and therefore the decomposition and deterioration of fragrance ingredients, especially ester fragrance ingredients, can be suppressed. Therefore, it is possible to freely create fragrances using various fragrance ingredients. Here, phosphoric acid and its salts include orthophosphoric acid (H ₃ PO ₄ ), pyrophosphoric acid (H ₄ P ₂ O ₇ ), metaphosphoric acid (HPO ₄ ), triphosphoric acid (H ₅ P ₃ O ₁₀ ), Examples include condensed phosphoric acids such as tetraphosphoric acid (H ₆ P ₄ O ₁₃ ), polymetaphosphoric acid ((HPO ₃ ) n), and alkali metal salts thereof, and these may be used alone or in combination of two or more. I can do it. Note that the alkali metal salts include alkali metal hydrogen phosphate (MH ₂ PO ₄ ),
Examples include dialkali metal hydrogen phosphate (M ₂ HPO ₄ ) and trialkali metal phosphate (M ₃ PO ₄ ). The method of treating aluminum hydroxide with an acid or its salt is not particularly limited, but for example, a method of suspending aluminum hydroxide in an aqueous solution of an acid or its salt and performing a neutralization treatment is preferred. Can be adopted. In this case, the aluminum hydroxide is preferably a 10 to 90% by weight slurry of an aqueous solution of an acid or its salt, particularly a 30 to 70% by weight slurry, and the concentration of the acid varies depending on the concentration of the aluminum hydroxide added. However, it is preferably 0.05 mol/~5 mol/. Also, the reaction is 10~
50℃, especially 20-30℃ for 2-50 hours, especially 2
It is preferable to carry out the reaction for up to 30 hours, and it is preferable to carry out stirring during the reaction. After the above operation is completed, the aluminum hydroxide removed from the slurry by filtration is washed with water or the like and dried to obtain modified aluminum hydroxide. In addition, in the above-mentioned modification operation, it is also possible to perform the modification operation once or repeatedly using one or more of the acids or salts at the same time.
The modification operation can also be repeated using two or more different acids or salts. For example, aluminum hydroxide is first treated with sulfuric acid, hydrochloric acid, etc.
It can then be treated with phosphoric acid, etc. Among the modified aluminum hydroxides mentioned above,
Particularly preferred are those obtained by treatment with phosphoric acid or its salts, especially orthophosphoric acid or its alkali metal salts. Products modified with this phosphoric acid or its salt have an aluminum phosphate-containing layer formed on the particle surface, but when using this type of modified aluminum hydroxide, the aluminum phosphate-containing layer on the surface A layer in which the entire layer is made of aluminum phosphate may be used, or a layer in which aluminum hydroxide and aluminum phosphate coexist may be used, but ESCA
(Electron Spectroscopy for Chemical
Analysis), the phosphorus atoms in the aluminum phosphate containing layer are 0.1 to
It is preferable to use one that indicates the presence of %. The above-mentioned modified aluminum hydroxide preferably has an aluminum phosphate-containing layer with a thickness of 10 to 1000 Å, and
Preferably, P ₂ O ₅ min is 0.01-0.5%. In the present invention, the above-mentioned modified aluminum hydroxide is blended into oral compositions such as toothpaste. In this case, the modified aluminum hydroxide is
This is slurry suspended in water at a ratio of 10% by weight.
It is preferable to use one having a pH of 4 to 8 and a copper plate polishing value of 1 to 10 mg. In addition, the copper plate polishing value is calculated by preparing a regular toothpaste containing 50% modified aluminum hydroxide, taking 50g of it, and adding 40g of it.
This is the abrasiveness when dispersed in 60% glycerin and subjected to 20,000 strokes using an inclined abrasive tester (Pepsodent type). ), see page 184]. In addition, when using modified aluminum hydroxide as an abrasive, it is preferable that the average particle size is 1 to 30μ, particularly 7 to 25μ;
If it is larger than 30μ, a rough feeling may occur, and if it is smaller than 1μ, the polishing properties may be poor.
However, when used as a polishing agent, finer particle sizes can also be used. Furthermore, in the present invention, silica is blended into the oral composition. In this case, in the present invention, properties such as the type of silica and the average particle diameter vary depending on the type of composition and are not particularly limited. For example, as silica, Cab-O-Sil, Aerosil
Gellable igneous ultrafine powdered silica sold under the trademarks of , Pyrogenic microscopic gelling silica with secondary particles of a few microns or less sold under the trademarks Tokusil, Vitasil, and Nipsil, or Abrasive silica and the like are appropriately selected, blended, and used depending on the type of composition. Here, as the silica-based abrasive, for example, JP-A-49-91994, JP-A-Sho.
49-94712, JP 50-64198, JP 50-65497, JP 51-928695,
JP-A-51-136841 and JP-A-54-4919
Those described in the No. 1 gazette, etc. are used. More specific examples include Zeodent, ZeO,
500 primary particles sold under the trademark Sident
Precipitated silica, silica xerogel, silica aerogel, etc. having a secondary particle size of 1 to 30 μm or less can be used. In this case, precipitated silica is particularly preferably used, with a SiO ₂ content of at least 70%, preferably at least 90%.
Alkali/alkaline earth metal oxide content 0-5
%, Aluminum, Magnesium to _SiO2 ,
Binding amount of metal oxides such as calcium 0-10%,
Preferably 0-5%, adhesion moisture content (loss on drying)
1-10%, average particle size 0.5-30μ, more preferably 1-15μ, specific surface area per 1g (BET method)
^500m2 or less, more preferably ^300m2 or less, refractive index
Those having properties of 1.44 to 1.47 and liquid absorption of 0.6 to 1.3 cc/g are preferably used. Specifically, U.S. Huber
Company's ZeO49, Zeodent113, US WRGrace Company's
Syloid AL-1, 63, 74, 404, J.Crossfield, UK
&Sons' Neosyl ET, Germany's Degussa
Examples include Sident3 and 20. The amount of modified aluminum hydroxide and silica to be blended is appropriately selected depending on the type of oral composition, etc., but usually modified aluminum hydroxide accounts for 5 to 95% of the total composition, especially in the case of toothpaste. is 5 to 50%, and on the other hand, silica is 3% or more of the entire composition, especially when a silica-based abrasive is used as the silica, 3 to 50%, especially 5 to 30%, gelatinous silica is used. In this case, it is preferably 3 to 10%. In this case, since the oral composition of the present invention contains modified aluminum hydroxide, it is possible to incorporate 3% or more of silica without causing bitterness or astringency. In addition, when using silica with a particle size of 1μ or less, it is necessary to mix more than 5 times the weight of modified aluminum hydroxide, and when using silica with a particle size of more than 1μ, add 0.5 times the weight of modified aluminum hydroxide. It is preferable to blend modified aluminum hydroxide in an amount equal to or more than twice the amount by weight in order to effectively suppress the bitterness and astringency of silica. In the present invention, the abrasive may be composed only of modified aluminum hydroxide or only modified aluminum hydroxide and a silica-based abrasive;
It may be used in combination with other abrasives. Here, other abrasives include, for example, calcium hydrogen phosphate 29-hydrate, calcium hydrogen phosphate anhydrate, calcium carbonate, calcium pyrophosphate, insoluble sodium metaphosphate, aluminum oxide, microcrystalline cellulose, resin, Examples include magnesium triphosphate and magnesium carbonate. Furthermore, conventional aluminum hydroxide can also be blended within a range that does not significantly impair the properties of the modified aluminum hydroxide. In addition, when using modified aluminum hydroxide and silica-based abrasives together with other abrasives, the ratio is not limited, and modified aluminum hydroxide may be used as the main abrasive, or other abrasives may be used as the main abrasive. It may be used as an abrasive, and these are determined depending on the purpose of use of the oral composition, but the amount of the modified aluminum hydroxide of the present invention in the abrasive is 20 to 100%, particularly 40 to 100%. It is preferable to do so. Furthermore, the oral composition of the present invention contains lysozyme chloride, dextranase, lytic enzyme, mutanase, chlorhexidine or a salt thereof, sorbic acid,
Alexidine, hinokitiol, cetylpyridinium chloride, alkylglycine, alkyldiaminoethylglycine salt, allantoin, ε-aminocaproic acid, tranexamic acid, azulene, vitamin E, sodium monofluorophosphate, sodium fluoride, stannous fluoride, water-soluble The oral composition of the present invention can contain active ingredients such as primary or secondary phosphates, quaternary ammonium compounds, sodium chloride, etc., and the oral composition of the present invention contains these active ingredients, especially fluorine-containing compounds, chlorhexidine, dextranase,
tranexamic acid, epsilon aminocaproic acid,
Allantoin chlorohydroxyaluminum, sodium chloride, etc. can be stably blended. The oral composition of the present invention may further contain other components depending on its type. for example,
Binder such as carboxymethyl cellulose, hydroxyethyl cellulose, alginate, carrageenan, gum arabic, polyvinyl alcohol, thickening agent such as polyethylene glycol, sorbitol, glycerin, propylene glycol, sodium lauryl sulfate, sodium dodecylbenzene sulfonate, hydrogenated coconut Foaming agents such as fatty acid monoglyceride monosulfate sodium, sodium lauryl sulfoacetate, N-lauroyl sodium sarcosinate, N-acyl glutamate, lauroyl diethanolamide, sucrose fatty acid ester, saccharin sodium, stevioside,
Sweeteners such as neohesperidyl dihydrochalcone, glycyrrhizin, perilartin, p-methoxinamicaldehyde, thaumatin, preservatives, flavor components, etc. may be blended. In this case, the oral composition of the present invention can lower the pH by incorporating the above-mentioned modified aluminum hydroxide, and therefore can effectively suppress decomposition and deterioration of the fragrance during storage. Therefore, the oral composition of the present invention contains menthol, carvone, peppermint oil, spearmint oil, anethole, ester fragrance accent,
Lactone fragrance accent, aldehyde fragrance accent, phenol fragrance accent,
Other fragrance ingredients listed in "Perfume and Flavor Chemicals" by STEFFEN ARCTANDER published by MONTCLAIR, NJ (USA), as well as orange oil, lemon oil, clove oil, cassia oil, fennel oil, cardamom oil,
Various fragrance ingredients can be effectively blended with essential oils such as cinnamon oil, coriander oil, eucalyptus oil, caraway oil, sage oil, and thyme oil. The oral composition of the present invention can be manufactured by a conventional method using the above-mentioned components, but when manufacturing a toothpaste, it is preferable that the pH thereof is 5 to 8. In this case, since the modified aluminum hydroxide of the present invention has a low pH, the pH of the composition can be easily adjusted to a range of 5 to 8, and is stably maintained within this pH range for a long period of time. Furthermore, the oral composition of the present invention can be filled into a plastic container, a laminate container made of aluminum laminated on one or both sides with plastic, or a metal container made of aluminum or the like. Since this can be suppressed, aluminum tubes and the like can be used without any problem. In addition, in the composition of the present invention, the addition of an alkali metal monofluorophosphate or magnesium chloride can further significantly suppress corrosion of aluminum. Effects of the Invention As explained above, the oral composition according to the present invention contains a specific amount of modified aluminum hydroxide obtained by treating aluminum hydroxide with an acid or a salt thereof and silica. As a result, the bitterness and astringency of silica are well suppressed, and therefore, the product has an excellent feeling of use without causing any discomfort during use. Next, an example of manufacturing modified aluminum hydroxide used in the present invention will be shown. Production example 1 Highly white aluminum hydroxide was crushed using a rotary impact type crusher (average particle size 6μ <light transmission method>), water (pure water or industrial water, hereinafter the same) was added and stirred, % slurry is prepared. Next, add orthophosphoric acid aqueous solution (concentration 2 mol/) to this,
After neutralization by stirring at room temperature for 2-4 hours, the slurry is filtered. Then add water to the residue to make 50%
The washing operation of preparing a slurry, stirring it, and then filtering it was repeated twice, and finally the residue was dried to obtain modified aluminum hydroxide. The surface of this aluminum hydroxide was coated with aluminum phosphate. Next, the particle surface of the modified aluminum hydroxide obtained in the above production example was examined using ESCA and FT-IR.
(Fourier Transformation Infrared). Results of analysis using ESCA The results are shown in Tables 1 and 2. In addition, the first
Table 2 shows the results of quantitative analysis of constituent ions, and Table 2 shows the results of state analysis of phosphorus.For comparison, commercially available (unmodified) aluminum hydroxide, aluminum phosphate mixed with it, and phosphorus The analysis results of aluminum acid are also listed.

【table】

[Table] From the results in Table 1, it is recognized that phosphorus ions are present in the modified aluminum hydroxide. Furthermore, since P and Na are reduced by etching, it is concluded that phosphorus is chemically bonded to the surface. Further, from the results in Table 2, the factors of the peak energy value of phosphorus are in good agreement between the modified aluminum hydroxide and aluminum phosphate, and it is recognized that the surface forming substance is aluminum phosphate. Analysis Results by FT-IR When the modified aluminum hydroxide was analyzed by FT-IR, the presence of aluminum phosphate was confirmed. Production Example 2 Modified aluminum hydroxide was obtained in the same manner as Production Example 1. However, when stirring for 2 to 4 hours in the neutralization treatment, an aqueous phosphoric acid solution was added at the latter stage. This modified aluminum hydroxide had aluminum hydroxide and aluminum phosphate coexisting on the surface. Next, an experimental example will be shown. Experimental Example Toothpastes having the following composition were prepared using the modified aluminum hydroxide obtained in Production Examples 1 and 2 as an abrasive, and the pH of these toothpastes was measured immediately after preparation and after storage for a predetermined period of time. For comparison, a similar experiment was conducted using unmodified aluminum hydroxide (commercially available aluminum hydroxide). The results are shown in Table 3. Toothpaste composition Abrasives 46% 60% Sorbit 26% Sodium carboxymethylcellulose 0.8% Carrageenan 0.3% Sodium lauryl sulfate 1.8% Gellable silica 3.0% Propylene glycol 2.5% Satucharin sodium 0.18% Butylparaben 0.002% Ethylparaben 0.005% Chlorhexidine hydrochloride 0.001% Fragrance 1.0% Purified water Balance Total 100.0%

[Table] From the results in Table 3, the toothpaste that uses modified aluminum hydroxide as an abrasive has a lower PH than the toothpaste that uses unmodified aluminum hydroxide, and has a long-lasting effect. It was confirmed that the PH was maintained at a low level. EXAMPLES Hereinafter, the present invention will be specifically explained by showing Examples and Comparative Examples. Examples 1 to 5, Comparative Examples 1 to 7 Toothpastes with the following compositions were each mixed with silica, modified aluminum hydroxide, commercially available aluminum hydroxide, and calcium hydrogen phosphate dihydrate in the proportions shown in Table 4. These toothpastes were prepared by a conventional method, filled into tubes, and stored at a predetermined temperature for a predetermined period of time, and the feeling of use was sensory evaluated. The results are also listed in Table 4. The evaluation criteria for the usability are as follows. Composition Powder Quantity shown in Table 4 Sodium carboxymethyl cellulose 1.0% Propylene glycol 2.0 Sodium lauryl sulfate 1.2 Sorbit (70%) 25 Flavor 1.0 Sodium saccharin 0.15 Water Total remaining 100.0% Usability evaluation criteria ○ Bitterness, astringency No, good feeling of use △ Slightly bitter and astringent taste × Considerably bitter and astringent taste, leaving a strange feeling after use.

【table】

[Table] Examples 6 to 9, Comparative Examples 8 to 11 Examples 6 to 9, Comparative Examples 8 to 11 with compositions shown in Table 5
Each of the 11 toothpastes was prepared by a conventional method and filled into tubes, and these toothpastes were stored at a predetermined temperature for a predetermined period of time to perform a sensory evaluation of the feeling of use.
The results are also listed in Table 5. Note that the evaluation criteria for the usability are the same as described above.

【table】

[Table] In general, stored toothpaste containing silica exhibits a marked bitterness and astringency compared to the toothpaste immediately after manufacture, but from the results in Tables 4 and 5, modified aluminum hydroxide It was found that the toothpaste of the present invention containing silica and silica had a good feel when used, with the bitterness and astringency of the silica suppressed even after long-term storage. In addition, in this case, for silica (Aerosil) with a particle size of 1μ or less, the particle size can be increased by blending modified aluminum hydroxide at least 5 times the weight of the silica (Aerosil).
0.5 for silica (Zeodent) exceeding 1μ
It has been found that by blending modified aluminum hydroxide in an amount equal to or more than twice the weight, the bitterness and astringency of silica can be effectively suppressed. On the other hand, toothpastes that contain silica and are made from commercially available aluminum hydroxide or calcium hydrogen phosphate dihydrate that have not been modified as abrasives taste bitter and astringent. Ta.

Claims (1)

[Claims] 1. Modified aluminum hydroxide obtained by treating aluminum hydroxide with an acid or its salt and silica are blended, and the amount of silica blended is 3% by weight of the entire composition. In addition to the above, the content of the modified aluminum hydroxide is 5 times or more by weight the amount of silica having a particle size of 1μ or less, and 0.5 times or more by weight the amount of silica having a particle size of more than 1μ. Composition. 2. Claim 1 uses, as the modified aluminum hydroxide, particles in which an aluminum phosphate-containing layer is formed on the surface of particles obtained by treating aluminum hydroxide with phosphoric acid or its salt.
Oral composition as described in . 3 P ₂ O in modified aluminum hydroxide ₅ minutes is 0.01~
The oral composition according to claim 2, which contains 0.5% by weight. 4. The oral cavity composition according to claim 2 or 3, wherein the modified aluminum hydroxide contains 0.1 to 10% by weight of phosphorus atoms in the aluminum phosphate-containing layer. 5. The oral cavity composition according to any one of claims 2 to 4, wherein the modified aluminum hydroxide has an aluminum phosphate-containing layer having a thickness of 10 to 1000 Å. 6 The average particle size of modified aluminum hydroxide is 1 to
The oral composition according to any one of claims 1 to 5, which has a particle size of 30μ. 7. The oral cavity composition according to any one of claims 1 to 6, which contains a silica thread abrasive as the silica. 8. The oral cavity composition according to any one of claims 1 to 6, which contains gelling silica as the silica. 9. The oral composition according to any one of claims 1 to 8, wherein the composition has a pH of 5 to 8. 10. The oral cavity composition according to any one of claims 1 to 9, which contains an ester fragrance.