RU2681077C1 - Dentifrice - Google Patents

Abstract

FIELD: hygiene.SUBSTANCE: invention relates to a dentifrice containing mixed granules obtained by adding unmixed granules containing water-insoluble powdered material (A) and an inorganic binder containing one or two substances selected from the group consisting of sodium silicate and colloidal silica (B) in a dentifrice, followed by stirring the dentifrice at a rate of at least 10 rpm and no more 250 rpm In the mixed granules in the dentifrice, the average value of the ratio of the area of the projection surface of the granules (SA) to the area of a circle, the diameter of which is the largest transverse diameter (DL) of the projection surface (SS), (SA/SS), is at least 0.5 and no more than 0.9 and the collapse strength of the mixed granules is not less than 1 gf/granule and not more than 20 gf/granule. Amount of mixed granules in the dentifrice is not less than 1 wt% and not more than 50 wt%. Unmixed granules, which are added to the dentifrice to obtain mixed granules in the dentifrice, are obtained by a roller granulation method, and among the following unmixed granules (b’)–(e-1’), according to the particle size distribution, which is determined by laser diffraction/scattering, granules (b') have a particle size of at least 100 mcm and less than 150 mcm, granules (c') have a particle size of not less than 150 mcm and less than 200 mcm, and granules (d') have a particle size of not less than 200 mcm and less than 250 mcm, and granules (e-1') have a particle size of not less than 250 mcm and less than 300 mcm. Volume ratio of the amount of granules (b') to the amount of granules (c’), (b’/c’), is not less than 0.6 and not more than 1.25, volume ratio of the amount of granules (d') to the amount of granules (c’), (d’/c’) is not less than 0.7 and not more than 1.2, and the volume ratio of the amount of granules (e-1') to the amount of granules (c’), (e-1’/c’), is not less than 0.4 and not more than 1.1, and the collapse strength of unmixed granules is not less than 1 gf/granule and not more than 20 gf/granule.EFFECT: disclosed dentifrice demonstrates high efficiency in removing dental plaque or stains even at low pressure, which is applied by a soft toothbrush, since the granules easily penetrate into shallow recesses, such as tooth perikymata, mesiolabial grooves, central ridges and distolabial surface grooves.4 cl, 4 tbl, 10 ex, 3 dwg

Description

FIELD OF THE INVENTION

The present invention relates to a dentifrice.

State of the art

In recent years, dentifrices have become known containing granules mixed in them, which are able to effectively remove dental plaque causing tooth decay and periodontal disease, and provide a tangible effect from the inclusion of granules. These granules are used in the form of spherical aggregated particles in order to prevent damage to the enamel on the surface of the teeth, gums, etc. Such granules may contain functional material, such as a drug, an enzymatic agent, and an abrasive agent or agent for a specific visual effect.

Known binders for such granules exist, including water-soluble binders, such as methyl cellulose and carboxymethyl cellulose, and water-insoluble organic binders, such as waxes. A dentifrice is also known that contains granules obtained by binding a water-insoluble powder material, such as a zeolite, to a water-insoluble inorganic binder, such as colloidal silicon dioxide (see Patent Source 1).

Alternatively, a dentifrice is known that contains spherical silica granules with a high deformation coefficient and obtained using silicic anhydride using a specific method according to the wet method (gel method) (see Patent Source 2).

List of references

Patent Sources

Patent Source 1: Japanese Patent Application JP-A-1-299211

Patent Source 2: Japanese Patent Application JP-A-2010-275260

SUMMARY OF THE INVENTION

The present invention relates to a dentifrice obtained by mixing granules containing water-insoluble powder material (A) and an inorganic binder (B),

where in the mixed granules in the dentifrice the average value of the ratio of the area of the projection surface of the granules (S _A ) to the area of the circle whose diameter represents the largest diameter (D _L ) of the projection surface (S _S ), (S _A / S _S ) is not less than 0.5 and not more than 0.9, and the fracture resistance of the mixed granules is not less than 1 gf / granule and not more than 20 gf / granule.

The present invention also relates to a dentifrice obtained by mixing granules containing water-insoluble powder material and an inorganic binder (B),

where in the mixed granules in the dentifrice, among the following granules (a) to (d), according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering:

granules (a) have a particle size of at least 50 μm and less than 100 μm,

granules (b) have a particle size of at least 100 microns and less than 150 microns,

granules (c) have a particle size of at least 150 microns and less than 200 microns, and

granules (d) have a particle size of not less than 200 microns and less than 250 microns,

where the volume ratio of the number of granules (b) to the number of granules (s), (b / s) is not less than 0.7 and not more than 1.2, the volume ratio of the number of granules (d) to the number of granules (s), (d / s) is not less than 0.2 and not more than 1, and the volume ratio of the number of granules (b) to the number of granules (d), (d / s) is more than 1 and not more than 5, the number of granules (s) in mixed granules is not less than 15 vol.% and not more than 55 vol.%, and the fracture resistance of mixed granules is not less than 1 gf / granule and not more than 20 gf / granule.

In recent years, as a result of changes in eating habits, lifestyle, etc., factors have intensified that lead to destructive processes in the oral cavity. Thus, various plaque films probably stick and remain on the surface of the teeth with large and small irregularities, such as pericomatia, mesial labial grooves, central crests and distal labial grooves. Despite the fact that the granules described in Patent Source 1 have an average particle strength and are easily destroyed, they still need improvement to adequately remove plaque adhering to the surface of the teeth, on which there are large and small irregularities. Also, the granules described in Patent Source 2, although they have a high deformation coefficient and give a good sense of the presence of granules, they also need to be improved to adequately remove plaque adhering to large and small depressions on the surface of the teeth, while applying slight pressure with soft a toothbrush to avoid a lot of pressure on the gums. Therefore, granules are required for dentifrices that easily penetrate such recesses on the surface of the tooth. It can be expected that any dentifrice obtained by mixing such granules will have increased efficiency in removing plaque and plaque even at low pressure, which is applied with a soft toothbrush, to reduce pressure on the gums.

Thus, the applicants of the present invention conducted various studies, and found that the dentifrice, which is obtained by mixing granules having a unique shape or a unique distribution of particle sizes and having a certain resistance to destruction, demonstrates high efficiency plaque removal or plaque removal efficiency even at low pressure, which is applied with a soft toothbrush, since these granules easily penetrate into shallow recesses of the tooth during interaction.

According to the present invention, the dentifrice is obtained by mixing specific granules having a unique shape or a unique particle size distribution, as well as having a certain resistance to destruction and collapsing under applied pressure, and thus the granules easily penetrate into shallow recesses on the teeth having a width of not more than 150 microns, such as pericomatia, mesial labial grooves, central crests and distal labial grooves, while providing a pleasant sensation of the presence of granules, without causing sensing foreign objects, and effectively tolerate the pressure exerted by the toothbrush, so that plaque and plaque such as colored plaque can be effectively removed. Therefore, even when a soft-bristled toothbrush is used, the granules can also effectively transfer pressure to shallow recesses, providing high plaque removal efficiency.

Brief Description of the Figures

[Figure 1] Figure 1 is a graph showing particle size distribution according to analysis of particle size distribution by laser diffraction / scattering of unmixed granules B 'used in the preparation of mixed granules present in the dentifrice of Example 2 and mixed granules B present in the dentifrice of Example 2.

[Figure 2] Figure 2 presents the image of the mixed granules B obtained by scanning electron microscopy, which are present in the dentifrice of example 2.

[Figure 3] Fig. 3 is a graph showing particle size distribution according to analysis of particle size distribution by laser diffraction / scattering of the mixed granules F present in the dentifrice of comparative example 1.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will now be described in detail.

The dentifrice of the present invention is obtained by mixing granules that have a unique shape or a unique particle size distribution and have a certain fracture resistance. The granules in such a dentifrice after mixing are granules containing water-insoluble powder material (A) and an inorganic binder (B), and hereinafter referred to as “mixed granules”. In contrast, granules that must be mixed with a dentifrice in order to ensure the presence of such mixed granules in a dentifrice are hereinafter referred to as “unmixed granules”.

As such a water-insoluble powder material (A), preferred are materials commonly used in dental abrasives, in particular inorganic materials. As used herein, “water insoluble” means that the amount dissolved in 100 g of water (20 ° C.) is not more than 1 g. Specific examples include one or more substances selected from the group consisting of light heavy calcium carbonate, calcium carbonate, zeolite, silicon dioxide, dibasic calcium phosphate, tricalcium phosphate, insoluble sodium metaphosphate, aluminum hydroxide, magnesium phosphate, calcium pyrophosphate and magnesium carbonate. These substances can be used individually, or two or more of them can be used in combination.

Of these water-insoluble powder materials (A), from the point of view of giving a unique shape or a unique distribution of particle sizes, which is described below in relation to mixed granules present in a dentifrice capable of exhibiting high plaque removal efficiency even at low pressure when a soft toothbrush is used, capable of sufficiently removing plaque and plaque such as colored plaque, and capable of enhancing a smooth feeling and a sensation of removal i plaque on the surface of the teeth, one or two substances selected from the group consisting of light calcium carbonate, heavy calcium carbonate, zeolite and silicon dioxide are preferred, and one or two substances selected from the group consisting of light calcium carbonate and heavy calcium carbonate are more preferred, and heavy calcium carbonate is even more preferred. As used here, a feeling of smoothness means a feeling where the tongue can glide smoothly over the surface of the teeth without feeling plaque or adherent plaque when the tongue touches the surface of the teeth. The feeling of plaque removal refers to the feeling when you can feel the smoothness of the surface of the teeth and plaque removal.

The average particle size of the water-insoluble powder material (A) is preferably not less than 0.1 microns, more preferably not less than 0.5 microns, even more preferably not less than 0.8 microns, even more preferably not less than 1 microns, from the point of view removal of plaque or plaque after the destruction of the granules. In addition, from the point of view of reducing the sensation of the presence of foreign objects in the mouth, the average particle size is preferably not more than 20 microns, more preferably not more than 15 microns, even more preferably not more than 10 microns, even more preferably not more than 5 microns. Also, the average particle size of the water-insoluble powder material (A) is preferably in the range from 0.1 to 20 μm, more preferably from 0.5 to 15 μm, even more preferably from 0.8 to 10 μm, even more preferably from 1 up to 5 microns.

In this regard, the average particle size can be measured by the method described in the examples.

The content of water-insoluble powder material (A) is preferably not less than 60 wt.%, More preferably not less than 70 wt.%, Even more preferably not less than 80 wt.%, Even more preferably not less than 82 wt.% In dry condition mixed granules, in terms of ensuring the gradual nature of the destruction and increase abrasiveness. The content of water-insoluble powder material (A) is preferably not more than 98 wt.%, More preferably not more than 96 wt.%, Even more preferably not more than 90 wt.% In the dry state in the mixed granules, from the point of view of preventing damage to the teeth . Also, the content of water-insoluble powder material (A) is preferably from 60 to 98 wt.%, More preferably from 70 to 96 wt.%, Even more preferably from 80 to 96 wt.%, Even more preferably from 82 to 90 wt. % dry in mixed granules.

The binder (B) contained in the mixed granules present in the dentifrice of the present invention binds to the water-insoluble powder material (A), forming voids in the mixed granules, and thus able to sufficiently remove dental plaques, and also provide a pleasant feeling of smoothness of the teeth and the feeling of removing plaque from the surface of the teeth. Examples of the binder (B) include one or more substances selected from the group consisting of water-soluble binders and water-insoluble binders. Specific examples of a water-soluble binder include one or more substances selected from the group consisting of sodium silicate, polyacrylic acid, treated celluloses, polyvinylpyrrolidone and silicones, and sodium silicate is preferred. Specific examples of a water-insoluble binder include one or more substances selected from the group consisting of colloidal silicon dioxide, magnesium aluminasilicate, synthetic aluminum silicate, calcium silicate and alumina, and colloidal silicon dioxide is preferred. Of these, from the point of view of a good manifestation of the effect of the present invention, the dentifrice preferably includes a water-soluble inorganic binder, and more preferably sodium silicate. When one or two substances selected from the group consisting of sodium silicate and colloidal silicon dioxide are included as a binder (B), the quality of the foam, foaming and the feeling of the presence of granules become satisfactory, and the feeling of smooth teeth and the feeling of removing plaque on the surface tooth can be improved.

Examples of such sodium silicate include one or more substances selected from the group consisting of sodium metasilicate (Na ₂ SiO ₃ ), sodium orthosilicate (Na ₄ SiO ₄ ), sodium disilicate (Na ₂ Si ₂ O ₅ ), sodium tetrasilicate (Na ₂ Si ₄ O ₉ ) and their hydrates.

Sodium silicate is usually represented by the molecular formula: Na ₂ O⋅nSiO ₂ ⋅mH ₂ O. The coefficient n (molecular ratio of SiO ₂ to Na ₂ O) is called the molar ratio, which can be represented by the following formula (I):

Molar ratio = mass ratio (wt.% SiO ₂ / wt .% Na ₂ O) × (molecular weight Na ₂ O / molecular weight SiO ₂ ) ... (I).

As sodium silicate, as a rule, water glass having various molar ratios can be used, in addition to sodium silicates No. 1, No. 2 and No. 3 described in JIS K1408. Of these, sodium silicate No. 3 is more preferred.

The physical properties of sodium silicate may vary depending on the molar ratio (coefficient n). However, in terms of compliance with Japanese Quasi-Drug Ingredients standards, as well as a good manifestation of the effect of the present invention and a pH shift of the mixed granules to the alkaline side, the molar ratio (coefficient n) is preferably not less than 2.0, more preferably not less than 2.4, even more preferably not less than 2.8, even more preferably not less than 3.0, and preferably not more than 4.0, more preferably not more than 3.5, even more preferably not more than 3.4, even more preferably not more than 3, 3. The molar ratio (coefficient n) is preferably from 2.0 to 4.0, more preferably from 2.4 to 3.5, even more preferably from 2.8 to 3.4, even more preferably from 3.0 to 3, 3.

The content of one or two substances selected from sodium silicate (dry matter content) and colloidal silicon dioxide in the inorganic binder (B) included in the mixed granules present in the dentifrice of the present invention is preferably not less than 60 wt. %, more preferably not less than 80 wt.%, even more preferably not less than 90 wt.% in component (B), from the point of view of granulating water-insoluble powder material, which is used as an inorganic bond conductive substance, and is preferably not more than 100 wt.%, in terms of technological properties, spraying a binder in the form of droplets to suppress the formation of coarse particles and increase the fracture resistance of granules mixed in a wet state. In this regard, the content of sodium silicate (dry matter content) and colloidal silicon dioxide in the above inorganic binder (B) represents the number of mixed granules that were removed from the dentifrice and dried at 90 ° C or higher to thereby remove water .

The content of component (B), which is one or two substances selected from the group consisting of sodium silicate (dry matter content) and colloidal silicon dioxide in the mixed granules present in the dentifrice of the present invention, is preferably not less than 1 wt. %, more preferably not less than 2 wt.%, even more preferably not less than 5 wt.%, even more preferably not less than 10 wt.% in the dry state in the mixed granules, from the point of view of providing moderate resistance to r wounded in a dry state and in water, and stability in a dentifrice, and from the point of view of achieving a gradual nature of destruction. The content of sodium silicate in the mixed granules present in the dentifrice of the present invention is preferably not more than 30 wt.%, More preferably not more than 20 wt.%, Even more preferably not more than 18 wt.% In the mixed granules, from the point view increase output. Also, the content of sodium silicate in the mixed granules present in the dentifrice of the present invention is preferably from 1 to 30 wt.%, More preferably from 2 to 20 wt.%, Even more preferably from 5 to 18 wt.%, Still more preferably 10 to 18 wt.%.

In the mixed granules present in the dentifrice of the present invention, the mass ratio of inorganic binder (B) to water-insoluble powder material (A), (inorganic binder (B) / water-insoluble powder material (A)), it is preferably not less than 0.02, more preferably not less than 0.05, even more preferably not less than 0.08, from the point of view of providing granulation of water-insoluble powder material, in which a moderate resistance to destruction, and in terms of ensuring the gradual nature of their destruction. In addition, from the point of view of reducing the number of large particles to achieve moderate resistance to destruction, the mass ratio is preferably not more than 0.5, more preferably not more than 0.3, even more preferably not more than 0.18. In this case, the mass ratio is preferably from 0.02 to 0.5, more preferably from 0.05 to 0.3, even more preferably from 0.08 to 0.18. In this regard, the content when the above component (B) includes sodium silicate is a value based on the dry matter content.

The mixed granules present in the dentifrice of the present invention preferably also contain one or more binders (C) selected from the group consisting of calcium silicate, magnesium oxide, titanium oxide and zinc oxide, from the point of view of imparting a suppression effect the formation of dental plaques and the strengthening of the network structure formed by water-soluble silicate or colloidal silicon dioxide, in order to improve the physical properties that provide for the gradual destruction of granules. As component (C), the mixed granules contain more preferably at least zinc oxide, and even more preferably zinc oxide and other binders.

The content of component (C) is preferably not less than 0.2 wt.%, More preferably not less than 0.5 wt.%, Even more preferably not less than 0.8 wt.% In dry condition in the mixed granules, from the point of view of improving inhibitory the effect of formation of dental plaques, and physical properties, providing a gradual nature of the destruction of the granules. Also, the content of component (C) in the mixed granules is preferably not more than 5 wt.%, More preferably not more than 3 wt.%, Even more preferably not more than 2 wt.% In the dry state, from the point of view of preventing an excessive increase in the resistance to destruction of the granules, as well as improving foaming and foam quality of a dentifrice containing mixed granules and suppressing a metallic taste in the mouth. Also, the content of component (C) in the mixed granules is preferably from 0.2 to 5 wt.%, More preferably from 0.5 to 3 wt.%, Even more preferably from 0.8 to 2 wt.% In the dry state.

The mass ratio of component (C) to component (B), (C / B) in the mixed granules is preferably not less than 0.02, more preferably not less than 0.05, even more preferably not less than 0.08 and preferably not more than 1 , more preferably not more than 0.5, even more preferably not more than 0.3, even more preferably not more than 0.2, from the point of view of achieving moderate resistance to destruction of the granules, as well as improving foaming and foam quality dentifrice, in which mixed granules are present, and the cleaning efficiency of recesses of various sizes on the surface of the teeth. Also, the mass ratio of component (C) to component (B), (C / B) in the mixed granules is preferably from 0.02 to 1, more preferably from 0.05 to 0.5, even more preferably from 0.08 to 0.3, even more preferably from 0.08 to 0.2.

The mixed granules present in the dentifrice of the present invention may contain organic fibers, medicinal ingredients, colorants or the like, if necessary, in addition to the above components, at such a level that the effects of the present invention are not adversely affected.

Additional components, in addition to the above components, can be used individually, or two or more of them can be used in combination.

The mixed granules present in the dentifrice of the present invention have a unique shape and an average value of the ratio of the projection surface area of the granules (S _A ) to the circumference of the circle whose diameter represents the largest diameter (D _L ) on the projection surface (S _S ), (S _A / S _S ) is not less than 0.5 and not more than 0.9. The projection surface area of the mixed granules in the present invention is a value measured using granules obtained by diluting the dentifrice with purified water to 10 wt.% Solution, washing the solution with purified water using a sieve with a hole size of 150 μm in accordance with JISZ8801-1 and then drying the granules remaining on the sieve at room temperature (25 ° C) for one day. The projection surface of the mixed granules means a surface photographed using a KEENCE VH-5500 (100x magnification). Based on the photographed digital image, analysis using software (WinROOF (MITANI CORPORATION)) is used to determine the ratio of the area on one projection surface of the granules (S _A ) to the area of a circle whose diameter represents the largest diameter (D _L ) on the projection surface (S _S ), (S _A / S _S ). In addition, based on the projection surface from a different direction or the projection surface obtained using other mixed granules, the average value S _A / S _{S is} determined. Thus, the average value of S _A / S _S is determined by the area of a circle whose diameter represents the largest diameter (D _L ) on the projection surface (S _S ), and the area of the projection surface (S _A ) will have a value approaching 1, since the granules are more spherical. In this regard, the mixed granules present in the dentifrice of the present invention are not spherical granules, but are so-called amorphous granules having a unique shape, that is, a deformed shape having many surface irregularities, since the average value of S _A / S _S (the area of a circle whose diameter represents the largest diameter (D _L ) on the projection surface (S _S )) is not less than 0.5 and not more than 0.9. In addition, the mixed granules of the present invention have a moderate amorphous shape, including a protrusion formed by breaking or partially chipping unmixed granules, and thus they do not cause the presence of foreign objects in the oral cavity. In contrast, the mixed granules are destroyed gradually due to the amorphous form, and when brushing is completed, many of the granules are destroyed, being able to provide the feeling that the brushing is finished.

It is assumed that the mixed granules present in the dentifrice of the present invention have a unique shape, and therefore, when pressure is applied to them with a toothbrush or the like, even in the oral cavity, the granules are easily destroyed due to the intense application of pressure to the protrusion on granules, and then gradually break down, starting with a ledge. This is believed to be due to the following reason: the starting particles aggregate to form intermediate particles, which then aggregate to form each particle of the mixed granules present in the dentifrice of the present invention, resulting in voids moderately interspersed in the granules; and as pressure is applied, destruction begins from protrusions of the intermediate particles on the surface. Then, before the final destruction, the granules are first transformed into intermediate particles, and the intermediate particles are gradually destroyed, turning into smaller ones. In addition, the mixed granules present in the dentifrice of the present invention are preferably granules obtained by adding unmixed granules to the dentifrice, followed by mixing in the manufacture of the dentifrice. Thus, at the place of use of the dentifrice of the present invention, when mixed granules obtained after mixing in the production are present, the mixed granules are not destroyed immediately when pressure is applied by the toothbrush, and the granules are destroyed gradually during brushing. Gradually collapsed granules collide with the surface of the teeth and penetrate into shallow recesses, such as dental pericomatia, with an effective transfer of pressure applied by the toothbrush to them, which as a result adequately ensures the removal of plaque or plaque and improves the feeling of smoothness on the surface of the teeth and sensation plaque removal.

The average value of the ratio of the projection surface area of the mixed granules (S _A ) to the circumference of the circle whose diameter represents the largest diameter (D _L ) on the projection surface (S _S ), (S _A / S _S ) is at least 0.5, preferably not less than 0.6, more preferably not less than 0.65, even more preferably not less than 0.7, from the point of view of ensuring a gradual destruction of the granules. The average value of the ratio of the projection surface area of the mixed granules (S _A ) to the circumference of the circle whose diameter represents the largest diameter (D _L ) on the projection surface (S _S ), (S _A / S _S ) is not more than 0.9, preferably not more than 0.85, more preferably not more than 0.82, from the point of view of providing moderate destruction of the granules for effective pressure transfer of the toothbrush, even with soft bristles. The average value of the ratio of the projection surface area of the mixed granules (S _A ) to the circumference of the circle whose diameter represents the largest diameter (D _L ) on the projection surface (S _S ), (S _A / S _S ) is at least 0.5 and not more than 0.9, preferably from 0.6 to 0.9, more preferably from 0.65 to 0.85, even more preferably from 0.75 to 0.82. In this regard, examples of soft bristles include conical shaped bristles, the cross-sectional area of which at the end of the bristles is gradually reduced. Conical bristles due to their thin tips provide a soft feeling and have the property that the tips easily penetrate into the space between the teeth.

The average ratio of the largest diameter (D _L ) to the smallest diameter (D _S ) on the projection surface of the mixed granules, (D _L / D _S ), is preferably not less than 1.2, more preferably not less than 1.3, even more preferably not less than 1.4, from the point of view that the granules are transformed into amorphous granules to ensure the gradual nature of the destruction and effective transfer of pressure of the toothbrush, even with soft bristles. The average ratio of the largest diameter (D _L ) to the smallest diameter (D _S ) on the projection surface of the mixed granules, (D _L / D _S ), is preferably not more than 1.8, more preferably not more than 1.7, even more preferably not more than 1.65, from the point of view of providing moderate destruction of the granules for efficient transfer of pressure applied by the toothbrush. Also, the average ratio of the largest diameter (D _L ) to the smallest diameter (D _S ) on the projection surface of the mixed granules, (D _L / D _S ), is preferably from 1.2 to 1.8, more preferably from 1.3 to 1 , 7, even more preferably from 1.4 to 1.65.

The mixed granules present in the dentifrice of the present invention also have a unique particle size distribution, and in the granules, among the following granules (a) to (d), according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering:

granules (a) have a particle size of at least 50 μm and less than 100 μm,

granules (b) have a particle size of at least 100 microns and less than 150 microns,

granules (c) have a particle size of at least 150 microns and less than 200 microns, and

granules (d) have a particle size of not less than 200 microns and less than 250 microns,

where the volume ratio of the number of granules (b) to the number of granules (s), (b / s) is not less than 0.7 and not more than 1.2, the volume ratio of the number of granules (d) to the number of granules (s), (d / s), is not less than 0.2 and not more than 1, the volume ratio of the number of granules (b) to the number of granules (d), (b / d) is more than 1 and not more than 5, and the content of granules (c) in mixed granules is not less than 15 vol.% and not more than 55 vol.%.

That is, since the volume ratio of the number of granules (b) and granules (c), (b / s) is in the above range, granules (b) are present in an amount equivalent to the number of granules (c) in the dentifrice. In contrast, the above volumetric ratio (d / s) is in the above range, and the volumetric ratio of granules (b / d) is more than 1 and not more than 5. Therefore, granules (b) are present in greater quantity than granules (d). Thus, granules having a particle size of at least 100 μm and less than 200 μm, granules (b) and (c) are present in large numbers, and granules (d) having a particle size of at least 200 μm are present in moderation. Thus, in an average amount there are granules (d) having a diameter of about 200 μm and easily transferring pressure from the bristles of the toothbrush, and in a large amount there are granules (b) and granules (c) easily penetrating into shallow recesses, such as pericomatia on the surface of the tooth, which are difficult to access for the bristles of the toothbrush. Thus, it is assumed that as pressure is applied by the toothbrush while brushing, these granules gradually break down while mixing with each other, and effectively transfer the pressure (granules) applied by the toothbrush, penetrating into shallow recesses such as pericomatia, being capable of effectively removing plaque and plaque, and improve the feeling of smoothness on the surface of the teeth and the feeling of removing plaque.

In this regard, the mixed granules present in the dentifrice of the present invention are granules that have a particle size of at least 50 μm, as determined by analysis of particle size distribution by laser diffraction / scattering. In addition, the mixed granules present in the dentifrice of the present invention are amorphous granules as described above, but it is assumed that the particle size, where the particle size distribution is determined by laser diffraction / scattering, will represent a value substantially approaching the average value of the largest diameter (D _L ) and the smallest diameter (D _S ) described above.

In the mixed granules present in the dentifrice of the present invention, the volume ratio of the number of granules (b) to the number of granules (s), (b / s) according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering is not less than 0.7, preferably not less than 0.75, more preferably not less than 0.8, in terms of ensuring efficient penetration into shallow recesses, moreover, effective penetration into recesses of a size having a width not greater than its 150 microns, at the same time showing a gradual nature of destruction, thereby improving the feeling of smoothness on the surface of the teeth after brushing. In the mixed granules present in the dentifrice of the present invention, the volume ratio of the number of granules (b) to the number of granules (s), (b / s) according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering is not more than 1.2, preferably not more than 1.1, more preferably not more than 1.0, even more preferably not more than 0.95, from the point of view that the granules (b) are destroyed gradually, while mixing with the granules ( c), thereby ensuring the presence of Via granules of various shapes. In addition, in the mixed granules present in the dentifrice of the present invention, the volume ratio of the number of granules (b) to the number of granules (s), (b / s) according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering, is not less than 0.7 and not more than 1.2, preferably not less than 0.75 and not more than 1.1, more preferably not less than 0.8 and not more than 1.0, even more preferably not less than 0 , 8 and no more than 0.95.

In the mixed granules present in the dentifrice of the present invention, the volume ratio of the number of granules (d) to the number of granules (s), (d / s), according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering is not less than 0.2, preferably not less than 0.25, more preferably not less than 0.3, from the point of view that the granules (d), which easily carry pressure from the bristles of the toothbrush, are destroyed gradually, mixing with granules ( b) and granules (c), providing it thus presence of granules of various shapes. In the mixed granules present in the dentifrice of the present invention, the volume ratio of the number of granules (d) to the number of granules (s), (d / s), according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering is not more than 1, preferably not more than 0.9, more preferably not more than 0.85, even more preferably not more than 0.8, from the point of view that the granules (d) also allow granules (b) and granules ( c) effectively penetrate into shallow recesses on the tooth x. Also in the mixed granules present in the dentifrice of the present invention, the volume ratio of the number of granules (d) to the number of granules (s), (d / s), according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering, is not less than 0.2 and not more than 1, preferably not less than 0.25 and not more than 0.9, preferably not less than 0.25 and not more than 0.85, even more preferably not less than 0.3 and not more 0.8.

In the mixed granules present in the dentifrice of the present invention, the volume ratio of the number of granules (b) to the number of granules (d), (b / d), according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering is not more than 1, preferably not less than 1.1, more preferably not less than 1.2, from the point of view that the particle size distribution among mixed granules, focusing on the content of granules (c), includes granules (b), easily penetrating into shallow holes Nia on tooth surfaces inaccessible for toothbrush bristles, in an amount greater than the amount of the pellets (d), with increasing thereby the efficiency of plaque removal, and also to improved foaming agents and foam quality dentifrice. In the mixed granules present in the dentifrice of the present invention, the volume ratio of the number of granules (b) to the number of granules (d), (b / d), according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering is not more than 5, preferably not more than 4, more preferably not more than 2.8, from the point of view that the granules (d), which are applied under the pressure of the toothbrush bristles, gradually break down, mixing with granules (b) and granules ( c) secured by pellets of various shapes. Also in the mixed granules present in the dentifrice of the present invention, the volume ratio of the number of granules (b) to the number of granules (d), (b / d), according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering, is more than 1 and not more than 5, preferably from 1.1 to 4, even more preferably from 1.2 to 2.8.

In this regard, the particle size distribution for the mixed granules present in the dentifrice of the present invention and the unmixed granules described below is obtained by analyzing the particle size distribution by laser diffraction / scattering. The particle size distribution is measured, in the case of mixed granules present in the dentifrice, using an aqueous solution prepared by diluting the dentifrice with water purified on ion exchange filters to 10 wt.%, And in the case of unmixed granules, which must be mixed into a dentifrice using an aqueous solution prepared by diluting granules intended for mixing with water treated with ion exchange chromatography, up to 5 wt.%. More specifically, an aqueous solution obtained by diluting a dentifrice in which mixed granules are present with water purified on ion-exchange filters up to 10 wt.% (Or an aqueous solution obtained by diluting unmixed granules with water purified on ion-exchange filters up to 5 wt. %), placed in a mixer (rotary mixer NPC-20 manufactured by NISSIN Corporation), operating in the following mode: 75 rpm, rotation in the horizontal direction and time 2 hours to disperse the granules. Then, an aqueous solution obtained by diluting a dispersed dentifrice in which mixed granules are present (or an aqueous solution obtained by dispersing unmixed granules) is kept at room temperature (25 ° C.) for one day. After aging, the aqueous solution was redispersed for 10 min on the above mixer and then the resulting aqueous solution was analyzed on a laser diffraction / scattering analyzer to determine the particle size distribution (Partica LA-950V2 manufactured by HORIBA, Ltd.) in the following mode: refractive index 1, 58, the circulation speed on a scale value of 5 and the mixing speed on a scale value of 5.

In the mixed granules present in the dentifrice of the present invention, the number of granules (c) according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering, is not less than 15 vol.% And not more than 55 vol.% in mixed granules. The amount of granules (c) in the mixed granules is not less than 15 vol.%, Preferably not less than 20 vol.%, More preferably not less than 23 vol.% And not more than 55 vol.%, Preferably not more than 50 vol.%, More preferably not more than 45 vol.%, even more preferably not more than 40 vol.%, from the point of view of ensuring the efficiency of removing plaque in the recesses on the surface of the teeth with a size having a width of not more than 150 microns, and removing plaque in small recesses on tooth surfaces with a size less than 200 microns wide, mixing with ugimi granules during brushing. Also, the number of granules (c) in the mixed granules is not less than 15 vol.% And not more than 55 vol.%, Preferably from 20 to 50 vol.%, More preferably from 23 to 45 vol.%, Even more preferably from 23 to 40 about.%.

In the mixed granules present in the dentifrice of the present invention, granules penetrating into recesses of a size having a width of less than 200 μm, inaccessible to toothbrush bristles, are present in large quantities in the dentifrice because the granules (c) are present in the largest number of granules (a) to (d), or granules (c) and granules (b) are present in substantially the same large amount. The total amount of granules (b) and granules (c) in the mixed granules is preferably not less than 30 vol.%, More preferably not less than 35 vol.%, Even more preferably not less than 40 vol.%, Even more preferably not less than 50 vol. %, from the point of view of providing high efficiency plaque removal in shallow recesses that are difficult to access for toothbrush bristles. The total number of granules (b) and granules (c) in the mixed granules is preferably not more than 85 vol.%, More preferably not more than 80 vol.%, Even more preferably not more than 75 vol.%, From the point of view to ensure sufficient transferring the pressure applied by the bristles of the toothbrush to the granules (a) to (c), and to ensure high plaque removal efficiency not only in recesses of a size having a width of less than 200 microns, but also in smaller recesses of a size having a width of not more than 100 microns even when using a soft toothbrush second bristles. Also, the total number of granules (b) and granules (c) in the mixed granules is preferably from 30 to 85 vol.%, More preferably from 35 to 80 vol.%, Even more preferably from 40 to 80 vol.%, Even more preferably from 50 to 75 vol.%.

In the mixed granules present in the dentifrice of the present invention, the volume ratio of the total number of granules (a) and granules (b) to the total number of granules (c) and granules (d), ((a + b) / (c + d)), according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering, is preferably not less than 0.5, more preferably not less than 0.6, even more preferably not less than 0.65, and preferably not more than 1, more preferably not more than 0.9, even more preferably not more than 0.85, with t points of view that the mixed granules effectively penetrate the recesses on the surface of the teeth of a size having a width of not more than 200 microns, transferring the brushing pressure applied by the toothbrush to small granules of a size of not more than 200 microns, even a soft bristled toothbrush, and that to improve foaming and the quality of the foam of the dentifrice in which the mixed granules are present. Also, the volume ratio of the total number of granules (a) and granules (b) to the total number of granules (c) and granules (d), ((a + b) / (c + d)) is preferably from 0.5 to 1, more preferably from 0.6 to 0.9, even more preferably from 0.65 to 0.85.

In addition, in the mixed granules of the present invention, granules (e) having a particle size of not less than 250 μm and not more than 350 μm may be present. The volume ratio of the total number of granules (a) and granules (b) to the number of granules (e), ((a + b) / e) in the mixed granules is preferably more than 1, more preferably not less than 1.1, even more preferably not less than 1.2, even more preferably not less than 1.3, and preferably not more than 20, and more preferably not more than 18, from the point of view of increasing the cleaning efficiency of granules (a) to (d). Also, the volume ratio of the total number of granules (a) and granules (b) to the number of granules (e), ((a + b) / e) is preferably more than 1 and not more than 20, more preferably from 1.1 to 20, more more preferably from 1.2 to 18, even more preferably from 1.3 to 18.

In the mixed granules present in the dentifrice of the present invention, the number of granules (a) according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering in the mixed granules, is preferably at least 3 vol.%, More preferably not less than 5 vol.%, from the point of view that the granules (a) are between granules having a particle size larger than that of granules (a), ensuring a gradual destruction, and that a large amount of mixed x granules penetrated into shallow recesses on the surface of the tooth, to improve the efficiency of removal of dental plaques, even more preferably not less than 7 vol.%, from the point of view of improving foaming and quality of the foam; and preferably not more than 15 vol.%, more preferably not more than 12 vol.%, even more preferably not more than 10 vol.%, from the point of view of facilitating the mixing of granules (b) and granules (c) and the penetration of granules into small recesses on the tooth surface. In addition, in the mixed granules present in the dentifrice of the present invention, the number of granules (a) according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering, is preferably from 3 to 15 vol.%, more preferably 5 to 12 vol.%, even more preferably 7 to 10 vol.% in the mixed granules.

In the mixed granules present in the dentifrice of the present invention, the number of granules (b) according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering in the mixed granules, is preferably at least 12 vol.%, More preferably not less than 15 vol.%, even more preferably not less than 20 vol.% and preferably not more than 50 vol.%, more preferably not more than 40 vol.%, even more preferably not more than 35 vol.%, from the point of view that granules (b) were located between granules having a particle size larger than the granule size (b), ensuring a gradual destruction, while thoroughly mixing with the granules (a).

In the mixed granules present in the dentifrice of the present invention, the number of granules (d) according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering in the mixed granules, is preferably at least 5 vol.%, More preferably not less than 10 vol.%, even more preferably not less than 12 vol.%, and preferably not more than 25 vol.%, more preferably not more than 22 vol.%, even more preferably not more than 20 vol.% in mixed granules, from the point view to gran ly (d) arranged between the beads (a) - (c), thereby ensuring a gradual character of destruction, and simultaneous transfer pressure of toothbrush bristles into pellets (a) - (c).

 In addition, in the mixed granules present in the dentifrice of the present invention, the number of granules (e) in the mixed granules according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering in the mixed granules, is preferably more than 0 vol %, more preferably not less than 1 vol.%, even more preferably not less than 2 vol.%, and preferably not more than 25 vol.%, more preferably not more than 20 vol.%, even more preferably not more than 18 vol.%, in terms of Oba improve the cleaning efficiency of the granules (a) - (c).

In the mixed granules present in the dentifrice of the present invention, the number of granules having a particle size of at least 350 μm according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering, is preferably 0 vol.% Or more than 0 vol.%, and not more than 35 vol.%, more preferably not more than 15 vol.%, even more preferably not more than 10 vol.%, even more preferably not more than 5 vol.% in mixed granules. In unmixed granules intended for use in preparing the mixed granules present in the dentifrice of the present invention, the number of granules having a particle size of at least 350 μm is preferably at least 10 vol.%, More preferably at least 15 vol.% , even more preferably not less than 20 vol.%, and preferably not more than 35 vol.%, in unmixed granules. Mixed granules present in the dentifrice of the present invention can preferably alter their particle size distribution by partially spalling the granules or breaking the granules in the mixing step after mixing the granules in the dentifrice. It is assumed that using the mixed granules that must be present in the dentifrice after the mixing step, when the dentifrice is used, the granules break down when brushing with a toothbrush, with easy penetration into shallow recesses on the tooth surface, while providing a well-tangible sensation of the presence of granules in the oral cavity.

The average particle size for the mixed granules present in the dentifrice of the present invention, r (microns), is preferably not less than 75 microns, more preferably not less than 100 microns, even more preferably not less than 125 microns, from the point of view that sufficient abrasion was provided, and preferably not more than 250 microns, more preferably not more than 220 microns, even more preferably not more than 210 microns, even more preferably not more than 180 microns, from the point of view of reducing the presence of extraneous DMetI in the oral cavity. Also, the average particle size for the mixed granules present in the dentifrice of the present invention, r (μm), is preferably from 75 to 250 μm, more preferably from 100 to 220 μm, even more preferably from 125 to 210 μm, even more preferably 125 to 180 microns.

In this regard, the average particle size for mixed granules r represents the average volumetric particle size, which is the average diameter in the particle size distribution for granules having a particle size of at least 50 μm, according to the particle size distribution determined by laser diffraction / scattering.

The fracture resistance of the aforementioned mixed granules having a unique shape or a unique particle size distribution present in the dentifrice of the present invention is not less than 1 gf / granule and not more than 20 gf / granule. Granules that have such resistance to destruction, are destroyed gradually due to their amorphous shape when pressure is applied with a toothbrush or the like. At the same time, the granules can penetrate into small cavities on the teeth, in order to thereby sufficiently remove plaque and plaque such as colored plaque, in addition to not causing the presence of foreign objects in the mouth. The fracture resistance of the mixed granules is at least 1 g / granule, preferably at least 2 g / granule, more preferably at least 3 g / granule, from the point of view of improving the effectiveness of the mixed granules in removing plaque, with a gradual destruction , and that the mixed granules penetrate into small cavities on the teeth, with the simultaneous gradual destruction from the pressure of the toothbrush, even when the toothbrush has soft bristles, due to the interaction of a unique shape and a unique particle size distribution of the mixed granules. The fracture resistance of mixed granules is not more than 20 gf / granule, preferably not more than 15 gf / granule, in terms of imparting moderate granulability to the granules, even when applying a low load using a soft toothbrush or the like, and reducing the sensation of the presence of foreign objects in the mouth , more preferably not more than 10 gf / granule, preferably not more than 8 gf / granule, from the point of view of improving the foaming and foam quality of the dentifrice in which the mixed granules are present s. Also, the fracture resistance of the above granules is not less than 1 gf / granule and not more than 20 gf / granule, preferably from 2 to 15 gf / granule, more preferably from 3 to 10 gf / granule, even more preferably from 3 to 8 gf / granule.

In this regard, the fracture resistance of the mixed granules used in the present invention is a wet value that represents the average value determined by taking 10-20 mixed granules from a dentifrice by compressing granules having a particle size of 180 to 200 μm using a compression tester (Shimadzu Corporation, MCTM-500) with a load increasing speed of 1.51 gf / s, and measuring the load at the time of destruction for each granule. In this regard, in the mixed granules used in the present invention, the resistance to destruction in the wet state is equivalent to the resistance to destruction in the dry state.

In relation to the mixed granules present in the dentifrice of the present invention, the inorganic binder of component (B) is prepared in an aqueous solution (hereinafter referred to as “an aqueous solution of an inorganic binder”) as necessary. This solution is mixed with the water-insoluble powder material of component (A), preferably an aqueous solution of an inorganic binder is added to component (A), thereby forming granules, which are preferably used as unmixed granules intended to be mixed into a dentifrice. When mixing them, you can additionally add a binder excipient component (C).

When sodium silicate is included in the dentifrice as component (B), an aqueous solution of sodium silicate can be used as sodium silicate. The sodium silicate content (dry matter content) in the aqueous sodium silicate solution is preferably not less than 20 wt.%, More preferably not less than 30 wt.%, More preferably not less than 35 wt.%, In the aqueous sodium silicate solution, from the point of view of in order to ensure the degradability of the granules and the processability of producing granules, and preferably is not more than 65 wt.%, and more preferably not more than 60 wt.%, from the point of view of reducing the number of large particles. In this regard, sodium silicate (dry matter content) in an aqueous solution of sodium silicate can be determined using the method described in the examples. In addition, when sodium silicate is included in the dentifrice as component (B), good granulation can be achieved with a mass ratio of component (A) to the inorganic binder aqueous solution (A / inorganic binder aqueous solution) entering in the range of about 10 to 1, preferably 8 to 5. Thus, an aqueous solution of an inorganic binder is preferably prepared by diluting an inorganic binder containing a sodium silicate component (B) water, the amount of which does not exceed 3 times the volume. Alternatively, the inorganic binder without dilution with water can be mixed with the water-insoluble powder material of component (A), preferably an aqueous solution of the inorganic binder can be added to component (A) to thereby form unmixed granules. An aqueous solution of an inorganic binder is preferably added to the water-insoluble powder material of component (A) at a low rate, from the point of view of aggregation, simultaneously with the effective formation of voids, thereby forming granules.

In particular, the rate of addition of an aqueous solution of an inorganic binder, for example, is preferably not more than 35 wt. h / min, more preferably not more than 20 wt. h / min, even more preferably not more than 10 wt. h / min, and, preferably, at least 0.5 parts by weight / min, more preferably at least 0.8 parts by weight / min, even more preferably not less than 1 wt. h / min, based on 100 wt. h water-insoluble powder material (A). The above range is suitable when using No. 1, No. 2, or No. 3 sodium silicates described in JIS K1408. Also, the rate of addition of an aqueous solution of an inorganic binder is preferably from 0.5 to 35 wt. h / min, more preferably from 0.8 to 20 wt.%, even more preferably from 1 to 10 wt.%, based on 100 wt. h water-insoluble powder material (A).

Also, the rate of addition of sodium silicate (dry matter content) is preferably not more than 19 wt. h / min, more preferably not more than 11 wt. h / min, even more preferably not more than 5.5 wt. h / min and preferably not less than wt. h / min, more preferably not less than wt. h / min, even more preferably not less than 0.3 wt. h / min per 100 wt. h water-insoluble powder material (A), in terms of what is described above. Also, the rate of addition of sodium silicate (dry matter content) is preferably from 0.1 to 19 wt. h / min, more preferably from 0.2 to 11 wt.%, even more preferably from 0.3 to 5.5 wt.% per 100 wt. h water-insoluble powder material (A).

As described above, in order to form unmixed granules for use in the preparation of mixed granules, by adding an aqueous solution (aqueous solution of an inorganic binder) of component (B), and, if necessary, adding component (C) to component (A), unmixed granules are preferably obtained by roller granulation. By mixing the unmixed granules obtained by the roller granulation method into a dentifrice, it is possible to provide not spherical granules obtained by the spray granulation method, which is traditionally widely used, but granules having the unique shape used in the present invention. Unmixed granules are also obtained having a wide particle size distribution over a wide range, and thus, granules having a unique particle size distribution used in the present invention can be obtained and also dispersed more voids in the granules. Thus, the mixed granules have the properties described above, and it is possible to ensure the gradual nature of their destruction.

Also, according to the roll granulation method described above, for the production of unmixed granules used to produce mixed granules, a rotary vascular granulator is preferably used. Examples of a vascular rotary granulator include drum-type granulators and cup-type granulators. Drum-type granulators are not particularly limited, provided that the granulators have a drum-shaped cylinder that rotates to process. In addition to horizontal or slightly inclined drum-type granulators, a drum-type conical granulator, a drum-type multi-stage conical granulator, and the like can be used. These devices may be of either a batch type or a continuous type.

In addition, an aqueous solution of an inorganic binder is added to the water-insoluble powder material of component (A) at a low speed, as described above, preferably using a multi-jet nozzle. In this regard, a multi-jet nozzle means a nozzle in which liquid and gas for atomization (for example, air and nitrogen) each flow through an independent liquid path close to the nozzle tip so that they can be mixed and sprayed. Specific examples may include two-jet nozzles, three-jet nozzles and four-jet nozzles.

The temperature of the inorganic binder aqueous solution, when the inorganic binder aqueous solution is supplied using a multi-jet nozzle, is preferably not less than 5 ° C, more preferably not less than 10 ° C and preferably not more than 50 ° C, more preferably not more than 30 ° C, in terms of ensuring its stability upon addition. Also, the temperature of the inorganic binder aqueous solution, when the inorganic binder aqueous solution is supplied using a multi-jet nozzle, is preferably 5 to 50 ° C, more preferably 10 to 30 ° C.

In this regard, when the binder excipient component (C) is used, component (C) is preferably mixed together with component (A). In particular, the step of producing unmixed granules by adding component (C) preferably includes the step of mixing the water-insoluble powder material of component (A) and the binder excipient of component (C) using a rotary vascular granulator, more preferably the step also includes the step of feeding the aqueous a solution of an inorganic binder as component (B) using a multi-jet nozzle to component (A) and component (C) (preferably a mixture of component (A) and component (C)).

The obtained unmixed granules, which are used in the preparation of mixed granules, are preferably further dried in order to ensure the stability of the mixed granules. Specific drying examples include drying on drying racks, drying in a fluidized bed, drying under reduced pressure, and microwave drying. Of these drying methods, drying on drying racks and drying in a fluidized bed are preferred in terms of equipment.

The drying temperature is preferably not less than 60 ° C, more preferably not less than 70 ° C, even more preferably not less than 80 ° C, from the point of view of thermal load. Also, the drying temperature is preferably not more than 200 ° C, more preferably not more than 150 ° C, still not more than 110 ° C, even more preferably not more than 90 ° C. Also, the drying temperature is preferably from 60 to 200 ° C, more preferably from 70 to 150 ° C, even more preferably from 80 to 110 ° C, even more preferably from 80 to 90 ° C.

The drying time is preferably not less than 10 minutes, more preferably not less than 20 minutes, even more preferably not less than 30 minutes, and preferably not more than 24 hours, more preferably not more than 20 hours, even more preferably not more than 5 hours. Also, the drying time is preferably is from 10 minutes to 24 hours, more preferably from 20 minutes to 20 hours, even more preferably from 30 minutes to 5 hours

In the unmixed granules used in the preparation of the mixed granules present in the dentifrice of the present invention, among the following granules (b ') to (e-1') according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering:

granules (b ’) have a particle size of not less than 100 microns and less than 150 microns,

granules (c ’) have a particle size of not less than 150 microns and less than 200 microns, and

granules (d ’) have a particle size of not less than 200 microns and less than 250 microns, and

granules (e ’) have a particle size of at least 250 microns and less than 300 microns,

where the volume ratio of the number of granules (b ') to the number of granules (s'), (b' / s') is preferably not less than 0.6 and not more than 1.25, the volume ratio of the number of granules (d ') to the number of granules (c '), (d' / s'), is preferably not less than 0.7 and not more than 1.2, and the volume ratio of the number of granules (e-1 ') to the number of granules (c'), (e-1 '/ s'), is preferably not less than 0.4 and not more than 1.1. That is, unmixed granules will have a broad peak, where granules having a particle size falling in the range of at least 100 μm and less than 300 μm are substantially the same amount. Mixing these granules gives mixed granules having a unique shape or a unique particle size distribution, as described above, to be present in the dentifrice.

In this regard, unmixed granules represent granules prior to mixing in a dentifrice used to produce mixed granules present in the dentifrice of the present invention having a particle size of at least 50 μm, where the particle size distribution is determined by laser diffraction / scattering . In addition, it is assumed that the particle size, where the particle size distribution is determined by laser diffraction / scattering, will have a value substantially close to the average of the largest diameter (D _L ') and smallest diameter (D _S ') described above.

In unmixed granules used for mixing, the volume ratio of the number of granules (b ') to the number of granules (s'), (b '/ s'), according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering, preferably is not less than 0.6, more preferably not less than 0.75, even more preferably not less than 0.8, from the point of view that the volume ratio of the number of granules (b) to the number of granules (c), (b / s) in mixed granules was taken as the desired value. In unmixed granules intended for mixing, the volume ratio of the number of granules (b ') to the number of granules (s'), (b '/ s'), according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering, preferably is not more than 1.25, more preferably not more than 1.15, even more preferably not more than 1.05, from the point of view that the gradual nature of the destruction of the mixed granules is effectively ensured. Also in unmixed granules, the volume ratio of the number of granules (b ') to the number of granules (s'), (b '/ s'), according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering, is preferably not less than 0 , 6 and not more than 1.25, more preferably from 0.75 to 1.15, even more preferably from 0.8 to 1.05.

In unmixed granules, the volumetric ratio of the number of granules (d ') to the number of granules (s'), (d '/ s'), according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering, is preferably not less than 0, 7, more preferably not less than 0.8, even more preferably not less than 0.85, from the point of view that the volume ratio of the number of granules (d) to the number of granules (s), (d / s) in the mixed granules is taken as the required value. In unmixed granules, the volume ratio of the number of granules (d ') to the number of granules (s'), (d '/ s'), according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering, is preferably not more than 1, 2, more preferably not more than 1.15, even more preferably not more than 1.05, from the point of view that the gradual nature of the destruction of the mixed granules is effectively ensured. Also in unmixed granules, the volume ratio of the number of granules (d ') to the number of granules (s'), (d '/ s'), according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering, is preferably not less than 0 , 7 and not more than 1.2, more preferably from 0.8 to 1.15, even more preferably from 0.85 to 1.05.

In unmixed granules, the volume ratio of the number of granules (e-1 ') to the number of granules (s'), (e-1 '/ s'), according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering, is preferably not less than 0.4, more preferably not less than 0.5, even more preferably not less than 0.6, even more preferably not less than 0.7, from the point of view that it is easy to obtain mixed granules having a gradual destruction. In unmixed granules, the volume ratio of the number of granules (e-1 ') to the number of granules (s'), (e-1 '/ s'), according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering, is preferably not more than 1.1 and more preferably not more than 1, from the point of view that the gradual nature of the destruction of the mixed granules is effectively ensured. Also, in unmixed granules, the volume ratio of the number of granules (e-1 ') to the number of granules (s'), (e-1 '/ s'), according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering, preferably is not less than 0.4 and not more than 1.1, more preferably from 0.5 to 1.1, even more preferably from 0.6 to 1, even more preferably from 0.7 to 1.

Also in unmixed granules used for mixing, the volume ratio of the number of granules (a ') having a particle size of at least 50 μm and less than 100 μm (granules (a')) to the number of granules (s'), (a '/ s' ), according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering, is preferably not less than 0.2, more preferably not less than 0.3, from the point of view that it is easy to obtain mixed granules having a gradual nature destruction. In unmixed granules intended for mixing, the volume ratio of the number of granules (a ') having a particle size of at least 50 μm and less than 100 μm (granules (a')) to the number of granules (s'), (a '/ s') according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering, is preferably not more than 1.2, more preferably not more than 1, from the point of view to obtain mixed granules that have a gradual fracture pattern and can effectively penetrate into shallow recesses I'm on the tooth surface. Also in unmixed granules, the volume ratio of the number of granules (a ') having a particle size of at least 50 μm and less than 100 μm (granules (a')) to the number of granules (s'), (a '/ s'), according to the distribution of particles in size, where the particle size distribution is determined by laser diffraction / scattering, is preferably from 0.2 to 1.2, more preferably from 0.3 to 1.

In unmixed granules, the number of granules (a ′) according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering, is preferably from 3 to 20 vol.%, More preferably from 5 to 18 vol.%, Even more preferably from 7 to 15 vol.% In unmixed granules, from the point of view to ensure good mixing of the granules (a) and granules (b), thereby ensuring the gradual nature of their destruction.

In unmixed granules, the number of granules (s') according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering, is preferably from 5 to 30 vol.%, More preferably from 8 to 25 vol.%, Even more preferably from 10 to 20 vol.% In unmixed granules, from the point of view of ensuring the presence of granules (c) in the required amount in mixed granules and in order to ensure good mixing of granules (a) and granules (b) to ensure their gradual destruction .

In addition, in unmixed granules, the volume ratio of the number of granules (e-2 ') having a particle size of at least 300 μm and less than 550 μm (granules (e-2')) to the number of granules (b) according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering, preferably is not less than 0.3, more preferably not less than 0.4, from the point of view to ensure easy preparation of mixed granules with a gradual fracture pattern. In unmixed granules, the volume ratio of the number of granules (e-2 ') to the number of granules (b'), (e-2 '/ b'), according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering, is preferably not more than 1, more preferably not more than 0.95, from the point of view to obtain mixed granules, which have a gradual destruction and can effectively penetrate into small recesses on the tooth surface. Also in unmixed granules, the volume ratio of the number of granules (e-2 ') to the number of granules (b'), (e-2 ') / b'), according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering, preferably from 0.3 to 1, more preferably from 0.4 to 0.95.

In unmixed granules, the number of granules (e-2 ') according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering, is preferably from 2 to 15 vol.%, More preferably from 5 to 12 vol.%, Even more preferably from 7 to 12 vol.% in unmixed granules, from the point of view that the granules (a) and granules (b) are prepared so that they mix well in the mixed granules, thereby ensuring a gradual fracture pattern.

In this regard, in unmixed granules, the number of granules having a particle size of at least 350 μm according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering, is preferably from 5 to 50 vol.%, More preferably from 10 to 45 vol.%, even more preferably from 15 to 42 vol.% in unmixed granules.

The average particle size for unmixed granules, r '(microns), is preferably not less than 50 microns, more preferably not less than 75 microns, even more preferably not less than 100 microns, from the point of view of ensuring sufficient abrasion, and preferably not more than 500 μm, more preferably not more than 450 μm, even more preferably not more than 400 μm, from the point of view of suppressing the sensation of the presence of foreign objects. Also, the average particle size for unmixed granules r ’(μm) is preferably from 50 to 500 μm, more preferably from 75 to 450 μm, even more preferably from 100 to 400 μm.

In this regard, the average particle size for unmixed granules r 'means the average volumetric particle size, which is the average diameter in the particle size distribution for granules having a particle size of at least 50 μm according to the particle size distribution, where the particle size distribution is determined laser diffraction / scattering.

The fracture resistance of unmixed granules is preferably not less than 1 gf / granule, more preferably not less than 2 gf / granule, even more preferably not less than 3 gf / granule, from the point of view of providing a gradual fracture pattern and high plaque removal efficiency for mixed granules present in the dentifrice of the present invention. The fracture resistance of the aforementioned unmixed granules is preferably not less than 20 gf / granule, more preferably not less than 15 gf / granule, even more preferably not less than 10 gf / granule, even more preferably not more than 8 gf / granule, from the point of view of providing moderate destructibility even when applying low pressure using a soft toothbrush or the like, and reducing the sensation of the presence of foreign objects for the mixed granules present in the dentifrice of this invention. Also, the fracture resistance of the above granules is preferably not less than 1 gf / granule and not more than 20 gf / granule, preferably from 2 to 15 gf / granule, more preferably from 3 to 10 gf / granule, even more preferably from 3 to 8 gf / granule .

In this regard, the fracture resistance of unmixed granules used in the present invention is a wet value and can be determined by the same method as for assessing the fracture resistance of mixed granules. In addition, in unmixed granules, the resistance to destruction in the wet state is equivalent to the resistance to destruction in the dry state.

The average value of the ratio of the projection surface area in unmixed granules (S _A ') to the area of a circle whose diameter represents the largest diameter (D _L ') on the projection surface (S _S '), (S _A / S _S ') is preferably not less than 0.5, more preferably not less than 0.6, even more preferably not less than 0.65, from the point of view of providing a gradual destruction of the mixed granules obtained from unmixed granules. The average value of the ratio of the projection surface area in unmixed granules (S _A ') to the area of a circle whose diameter represents the largest diameter (D _L ') on the projection surface (S _S '), (S _A / S _S ') is preferably not less than 0.9, more preferably not more than 0.85, from the point of view of providing moderate destructibility of the mixed granules obtained from unmixed granules to effectively transfer the pressure exerted by the toothbrush. In this regard, the entire projection surface area in unmixed granules (S _A '), the largest diameter (D _L '), the circumference of a circle whose diameter represents a given diameter (S _S ') and the average ratio (S _A / S _S ') represent values that can be determined by the same method as for the above mixed granules.

The average ratio of the largest diameter (D _L ') to the smallest diameter (D _S ') on the projection surface of unmixed granules (D _L '/ D _S ') is preferably not less than 1.2, more preferably not less than 1.3, even more preferably not less than 1.5, from the point of view of obtaining from the unmixed granules mixed granules that become amorphous, thereby ensuring a gradual fracture pattern. The average ratio of the largest diameter (D _L ') to the smallest diameter (D _S ') on the projection surface of the unmixed granules (D _L '/ D _S ') is preferably not more than 2, more preferably not more than 1.8, even more preferably not more than 1.75, from the point of view that the mixed granules obtained from unmixed granules have moderate destructibility to ensure effective transfer of pressure applied by the toothbrush. In addition, the average ratio of the largest diameter (D _L ') to the smallest diameter (D _S ') on the projection surface of unmixed granules (D _L '/ D _S ') is preferably from 1.2 to 2, more preferably from 1, 3 to 1.8, even more preferably 1.5 to 1.75.

The amount of mixed granules present in the dentifrice of the present invention obtained using the above unmixed granules is preferably at least 1 wt.%, More preferably at least 3 wt.%, Even more preferably at least 5 wt.% In the agent for brushing the teeth of the present invention, from the point of view to ensure that the nature of the destruction of the granules is sufficiently ensured, thereby increasing the effect of removing plaque and plaque, and also improves the feeling of use redstva dentifrice. The amount of mixed granules present in the dentifrice of the present invention is preferably not more than 50 wt.%, More, preferably not more than 30 wt.%, Even more preferably not more than 25 wt.% In the dentifrice of the present invention , from the point of view of providing the effect of removing plaque and plaque without the sensation of the presence of foreign objects and damage to tooth enamel. Also, the amount of mixed granules present in the dentifrice of the present invention is preferably from 1 to 50 wt.%, More preferably from 3 to 30 wt.%, Even more preferably from 5 to 25 wt.%, Even more preferably from 5 to 20 wt.% In the dentifrice of the present invention.

To obtain mixed granules having a unique shape or a unique particle size distribution as described above and present in the dentifrice of the present invention, unmixed granules are preferably mixed into the dentifrice after a binder is added to the dentifrice agent described below. In addition, in the step after mixing the binder into the dentifrice, the above unmixed granules are added to the dentifrice, and the dentifrice obtained is mixed, depending on the type of mixer and mixing time, preferably with stirring at a speed of at least 10 rpm, more preferably at least 20 rpm; preferably with stirring at a speed of not more than 250 rpm; and preferably with stirring at a speed of at least 10 rpm and no more than 250 rpm, more preferably with stirring at a speed of at least 20 rpm and not more than 250 rpm In order to mix the dentifrice with such a stirring speed, mixing can be performed using a known mixer, for example, a universal mixer for mixing (5XDMV-10-R manufactured by Dalton Co., Ltd.) and a paddle mixer (paddle mixer TK 2SL -10 manufactured by Tokushu Kika Kogyo Co., Ltd.). When using the above universal mixer for mixing, the rotational mixing speed is preferably from 40 to 230 rpm, more preferably from 90 to 200 rpm, and the mixing speed with turning is preferably from 20 to 110 rpm, more preferably from 35 to 75 rpm. When the above paddle mixer is used, the mixing speed is preferably from 10 to 70 rpm, and the mixing speed of the turbine is preferably from 20 to 90 rpm. In this regard, to mix the dentifrice it is only necessary to disperse the granules in the dentifrice. When the mixing speed is low, it is only necessary to increase the mixing time. In contrast, when the mixing speed is high, it is only necessary to reduce the mixing time. From this point of view, the mixing time is preferably from 5 minutes to 90 minutes, more preferably from 10 minutes to 60 minutes.

The method for preparing the dentifrice of the present invention preferably includes the step of mixing the dentifrice after adding unmixed granules. The inclusion of this stage makes it possible to obtain mixed granules having a particle size distribution that includes many granules with a particle size of 100 to 200 μm and includes many granules with a particle size smaller than the maximum particle size in the particle size distribution range obtained from unmixed granules having a wide distribution of particle sizes.

The dentifrice of the present invention is obtained by mixing granules containing the above component (A) and component (B), and, if necessary, component (C) or component (D). Since the granules present in the dentifrice after mixing (mixed granules) have a unique shape or a unique particle size distribution and exhibit a gradual fracture pattern, it is preferable to additionally mix a surfactant in order to provide a high cleaning effect due to a synergistic effect with foaming. This leads to good foaming and contributes to the stability of foaming and, thus, the effect of removing plaque or plaque can sufficiently manifest itself in small areas, such as the spaces between the teeth. In addition, there is a feeling of smoothness on the surface of the teeth in the oral cavity after applying the dentifrice of the present invention, so as to also be able to improve the sensation of its use.

Examples of a surfactant that can be used include anionic surfactants, nonionic surfactants, and amphoteric surfactants. Examples of the anionic surfactant include alkyl sulfates such as sodium lauryl sulfate and sodium myristyl sulfate; N-acyl sarcosinates such as sodium N-lauroyl sarcosinate and sodium N-myristoyl sarcosinate; N-acylglutamates, such as sodium N-palmitoylglutamate, sodium N-methyl-N-acyl taurine, sodium N-methyl-N-acylalanine, sodium α-olefin sulfonates and sodium dioctyl sulfosuccinate. The anionic surfactant is preferably anionic surfactants and more preferably alkyl sulphates such as sodium lauryl sulphate in order to provide good foaming and a good feeling for using a dentifrice.

The amount of surfactant added is preferably at least 0.2 wt.%, More preferably at least 0.3 wt.%, Even more preferably at least 0.5 wt.% In the dentifrice of the present invention, from vision in order to provide good taste, while providing good foaming, thereby improving the cleansing effect and the favorable feeling of using a dentifrice. Also, the amount of surfactant added is preferably not more than 2.0 wt.%, More preferably not more than 1.7 wt.%, Even more preferably not more than 1.5 wt.% In the dentifrice of the present invention, s point of view to prevent deterioration in taste. In addition, the amount of added surfactant is preferably from 0.2 to 2.0 wt.%, More preferably from 0.3 to 1.7 wt.%, Even more preferably from 0.5 to 1.5 wt. % in the dentifrice of the present invention. The mass ratio of the above mixed granules to a surfactant (mixed granules / surfactant) in the dentifrice of the present invention is preferably from 0.5 to 250, more preferably from 2 to 100, even more preferably from 4 to 40.

The amount of added anionic surfactant is preferably not less than 0.2 wt.% E, more preferably not less than 0.3 wt.%, Even more preferably not less than 0.5 wt.% In the dentifrice of the present invention, in terms of providing good taste while providing good foaming, improving the cleaning effect and the sensation of using a dentifrice. Also, the amount of anionic surfactant added is preferably not more than 2.5 wt.%, More preferably not more than 2.0 wt.%, Even more preferably not more than 1.7 wt.% In the dentifrice of the present invention, in terms of preventing deterioration in taste. Also, the amount of mixed anionic surfactant is preferably from 0.2 to 2.5 wt.%, More preferably from 0.3 to 2.0 wt.%, Even more preferably from 0.5 to 1.7 wt.% in the dentifrice of the present invention. The amount of mixed alkyl sulfate is preferably not less than 0.2 wt.%, More preferably not less than 0.3 wt.%, Even more preferably not less than 0.5 wt.% In the dentifrice of the present invention, from the point of view to provide good taste while providing good foaming, improving the cleansing effect and the feeling of using a dentifrice. Also, the amount of alkyl sulfate added is preferably not more than 2.5 wt.%, More preferably not more than 2.0 wt.%, Even more preferably not more than 1.7 wt.% In the dentifrice of the present invention, from the point of view of to prevent taste impairment. Also, the amount of alkyl sulfate added is preferably from 0.2 to 2.5 wt.%, More preferably from 0.3 to 2.0 wt.%, Even more preferably from 0.5 to 1.7 wt.% In the cleaning agent teeth of the present invention.

A binding agent is preferably added to the dentifrice of the present invention. Examples of the binding agent include sodium carboxymethyl cellulose, sodium polyacrylate, hydroxyethyl cellulose, montmorillonite, xanthan gum, carrageenan, sodium alginate, guar gum and pectin, and one or more substances selected from them can be used. The dentifrice is preferably a dentifrice paste, and preferably one or more substances selected from the group consisting of sodium carboxymethyl cellulose, xanthan gum and carrageenan are admixed. The amount of binding agent that is added to the dentifrice of the present invention is preferably not less than 0.1 wt.%, More preferably not less than 0.5 wt.%, Even more preferably not less than 0.7 wt.%, And preferably not more than 3 wt.%, more preferably not more than 2 wt.%, even more preferably not more than 1.8 wt.% in the dentifrice of the present invention, from the point of view to ensure effective diffusion of the above components in the cavity mouth, simultaneously dissolving and dispersing components, to ensure the effective manifestation of the effect of removing plaque or plaque with mixed granules that gradually break down, being able to improve the feeling of smoothness on the tooth surface and the feeling of removing plaque, and provide good foaming due to a synergistic effect with a surfactant, and from the point view of maintaining good foaming during toothbrushing as a result of the synergistic effect of granules and surfactants. Also, the amount of added binder in the dentifrice of the present invention is preferably from 0.1 to 3 wt.%, More preferably from 0.5 to 2 wt.%, Even more preferably from 0.7 to 1.8 wt. .% in the dentifrice of the present invention. The mass ratio of the above mixed granules to a binding agent (mixed granules / binding agent) in the dentifrice of the present invention is preferably from 0.2 to 500, more preferably from 1 to 60, even more preferably from 2.5 to 30, from the point of view to ensure effective diffusion of the above components in the oral cavity, while dissolving and dispersing the components, to ensure the effective manifestation of the effect of removing dental plaque or plaque with mixed granules, which gradually collapse, being able to improve the feeling of smoothness on the surface of the teeth.

The dentifrice of the present invention is preferably additionally mixed with a thickener - silicon dioxide in addition to the aforementioned binding agent, from the point of view of increasing storage stability and improving oral sensations. The thickener - silicon dioxide is silicon dioxide containing a certain amount of absorbed oil from 200 to 400 ml / 100 g, and differs from abrasive silicon dioxide containing an amount of absorbed oil from 50 to 150 ml / 100 g. The amount of absorbed oil in this description refers to the amount of oil that can be applied to silicon dioxide and is determined by analysis based on the JISK5101-13-2 standard (developed in 2004) by the amount of absorbed boiled linseed oil. The amount of silica thickener mixed in the dentifrice of the present invention is preferably at least 1 wt.%, More preferably at least 2 wt.%, Even more preferably at least 3 wt.%, And preferably not more than 15 wt. %, more preferably not more than 10% by weight in the dentifrice of the present invention. Also, the amount of silica thickener mixed in the dentifrice of the present invention is preferably from 1 to 15 wt.%, More preferably from 2 to 10 wt.%, Even more preferably from 3 to 10 wt.%.

A humectant may additionally be added to the dentifrice of the present invention. Examples of the humectant include one or more substances selected from the group consisting of sorbitol, glycerol, propylene glycol, 1,3-butylene glycol, ethylene glycol, polyethylene glycol, polypropylene glycol, xylitol, maltitol, lactitol and erythritol. The amount of humectant added to the dentifrice of the present invention is preferably not less than 5 wt.%, More preferably not less than 10 wt.%, Even more preferably not less than 15 wt.% And preferably not more than 60 wt.%, more preferably not more than 50 wt.%, even more preferably not more than 40 wt.% in the dentifrice of the present invention, from the point of view to ensure effective diffusion of the above components in the oral cavity when the components are dissolved and dispersed, will provide l the effective manifestation of the effect of removing dental plaque or plaque with mixed granules, which are destroyed gradually, and ensuring good foaming together with a surfactant. Also, the amount of humidifier added to the dentifrice of the present invention is preferably from 5 to 60 wt.%, More preferably from 10 to 50 wt.%, Even more preferably from 15 to 40 wt.% In the dentifrice according to the present invention.

In the dentifrice of the present invention, water may be further admixed. The moisture content of the dentifrice of the present invention is preferably not less than 3 wt.%, More preferably not less than 5 wt.%, Even more preferably not less than 7 wt.%, And preferably not more than 50 wt.%, More preferably not more than 45 wt.%, even more preferably not more than 40 wt.% in the dentifrice of the present invention, from the point of view to ensure effective diffusion of the above components in the oral cavity when dissolving and dispersing the components, to ensure effective manifestation Effect of removal of dental plaque or plaque granules are gradually destroyed by being able to exhibit a high efficiency of plaque removal, even at low pressure, supplied a soft toothbrush and the like, and further providing good foaming, together with surfactant. Also, the moisture content in the dentifrice of the present invention is preferably from 3 to 50 wt.%, More preferably from 5 to 45 wt.%, Even more preferably from 7 to 40 wt.% In the dentifrice of the present invention, in terms of providing good solubility, dispersion and plaque or plaque removal efficiency. In this regard, the water content is the amount obtained by summing the total content of added water and the water content of other mixed components. This content can be calculated from the added amount or can be measured, for example, using a moisture titrator according to the Karl Fischer method. Examples of a Karl Fischer moisture titrator that can be used include a moisture trace meter (HIRANUMA SANGYO Co., Ltd.). Using this device, 5 g of dentifrices are suspended in 25 g of anhydrous methanol and 0.02 g of suspension is taken for analysis, thereby obtaining a moisture content, taken as the amount of added water. The ratio of said mixed granules to moisture content (e.g., mixed granules / moisture content) in the dentifrice of the present invention is preferably 0.02 to 15, more preferably 0.1 to 6, even more preferably 0.2 up to 3, in terms of providing good solubility, dispersibility and removal efficiency of dental plaque or plaque.

Preferably, a pH adjusting agent may be added to the dentifrice of the present invention. Examples of a pH adjusting agent include phosphoric acid and its salts (sodium phosphates such as sodium hydrogen phosphate and sodium dihydrogen phosphate), citric acid and its salts, malic acid and its salts, gluconic acid and its salts, maleic acid and its salts, aspartic acid acid and its salts, gluconic acid and its salts, succinic acid and its salts, glucuronic acid and its salts, fumaric acid and its salts, glutamic acid and its salts, adipic acid and its salts, hydrochloric acid, sodium hydroxide and potassium hydroxide, in terms of to improve the taste and prevent damage to the dentifrice of the present invention, and one or preferably two or more substances selected from them can be used. The dentifrice of the present invention preferably contains phosphoric acid or a salt thereof selected from the group consisting of disodium hydrogen phosphate and sodium dihydrogen phosphate as a pH adjusting agent. The added amount of a pH adjusting agent is not particularly limited provided that the desired pH is achieved, but is preferably from 0.01 to 5 wt.%, More preferably from 0.1 to 3 wt.% In the dentifrice of the present invention . In this regard, the pH of the dentifrice of the present invention is preferably above 7, more preferably not lower than 7.5, even more preferably not lower than 7.8, and preferably not higher than 11, more preferably not higher than 10, even more preferably no more than 9.5. The pH value of the dentifrice of the present invention, in this case means the value obtained by analyzing the dentifrice diluted to 10 wt.% With water at 25 ° C using a pH electrode.

Other components than the ones described above may be mixed into the dentifrice of the present invention, such as abrasives, excipients, sweeteners, preservatives, perfumes, medicinal ingredients, colorants and other commonly used components.

The above and other components may be used individually, or two or more of them may be used in combination.

With respect to the embodiments of the present invention described above, the following granules for dentifrice and the following dentifrice are further disclosed.

[1] A dentifrice obtained by mixing granules containing water-insoluble powder material (A) and an inorganic binder (B),

where in the mixed granules in the dentifrice the average value of the ratio of the area of the projection surface of the granules (S _A ) to the area of the circle whose diameter represents the largest diameter (D _L ) of the projection surface (S _S ), (S _A / S _S ) is not less than 0.5 and not more than 0.9, and the fracture resistance of the mixed granules is not less than 1 gf / granule and not more than 20 gf / granule.

[2] The dentifrice according to [1] described above, wherein, in the mixed granules in the dentifrice, the average ratio of the largest diameter (D _L ) to the transverse diameter (D _S ) on the projection surface of the mixed granules, ( D _L / D _S ), preferably is not more than 1.8, more preferably not more than 1.7, even more preferably not more than 1.65, and preferably not less than 1.2, not less than 1.3, even more preferably not less than 1.4.

[3] A dentifrice in p. [1] or [2] described above, where the average value of the ratio of the projection surface area of the mixed granules (S _A ) to the circumference of a circle whose diameter represents the largest transverse diameter (D _L ), on the projection surface (S _S ), (S _A / S _S ) is not more than 0.6, more preferably not more than 0.65, even more preferably not more than 0.85, even more preferably not more than 0.82.

[4] A dentifrice obtained by mixing granules containing water-insoluble powder material (A) and an inorganic binder (B),

where in the mixed granules in a dentifrice, among the following granules (a) to (d) according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering:

granules (a) have a particle size of at least 50 μm and less than 100 μm,

granules (b) have a particle size of at least 100 microns and less than 150 microns,

granules (c) have a particle size of at least 150 microns and less than 200 microns, and

granules (d) have a particle size of not less than 200 microns and less than 250 microns,

where the volume ratio of the number of granules (b) to the number of granules (s), (b / s) is not less than 0.7 and not more than 1.2, the volume ratio of the number of granules (d) to the number of granules (s), (d / s) is not less than 0.2 and not more than 1, and the volume ratio of the number of granules (b) to the number of granules (d), (d / s) is more than 1 and not more than 5, the number of granules (s) in mixed granules is not less than 15 vol.% and not more than 55 vol.%, and the fracture resistance of mixed granules is not less than 1 gf / granule and not more than 20 gf / granule.

[5] The dentifrice according to [4] described above, wherein, in the mixed granules, the volume ratio of the number of granules (b) to the number of granules (s), (b / s), according to the particle size distribution, where the particle distribution size determined by laser diffraction / scattering, is not less than 0.75, more preferably not less than 0.8, and preferably not more than 1.1, more preferably not more than 1.0, even more preferably not more than 0.95.

[6] Means for cleaning teeth according to paragraphs. [4] or [5] described above, where in mixed granules the volume ratio of the number of granules (d) to the number of granules (s), (d / s), according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering, is preferably not less than 0.25, more preferably not less than 0.3, and preferably not more than 0.9, more preferably not more than 0.85, even more preferably not more than 0.8.

[7] A means for brushing teeth according to one of paragraphs. [4] - [6] described above, where in mixed granules the volume ratio of the number of granules (b) to the number of granules (d), (b / d), according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering, is preferably not less than 1.1, more preferably not less than 1.2, and more preferably not more than 4, even more preferably not more than 2.8.

[8] A means for brushing teeth according to one of paragraphs. [4] - [7] described above, where in the mixed granules the number of granules (c) according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering, is preferably not less than 20 vol.%, More preferably not less than 23 vol.%, And preferably not more than 50 vol.%, More preferably not more than 45 vol.%, Even more preferably not more than 40 vol.%.

[9] A means for brushing teeth according to one of paragraphs. [4] to [8] described above, wherein in the mixed granules, the total number of granules (b) and granules (c) is preferably not less than 30 vol.%, More preferably not less than 35 vol.%, Even more preferably not less than 40 vol.%, even more preferably not less than 50 vol.%, and preferably not more than 85 vol.%, more preferably not more than 80 vol.%, even more preferably not more than 75 vol.%.

[10] A means for brushing your teeth according to one of paragraphs. [4] - [9] described above, where in mixed granules the volume ratio of the total number of granules (a) and granules (b) to the total number of granules (c) and granules (d), ((a + b) / (c + d)), according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering, is preferably not less than 0.5, more preferably not less than 0.6, even more preferably not less than 0.65 and preferably not more 1, more preferably not more than 0.9, even more preferably not more than 0.85.

[11] A means for brushing your teeth according to one of paragraphs. [4] - [10] described above, where in the mixed granules ((a + b) / e), according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering, the volume ratio of the total number of granules (a) and granules (b) to the number of granules (e) is preferably not more than 1, more preferably not less than 1.1, even more preferably not less than 1.2, even more preferably not less than 1.3, and preferably not more than 20, more preferably not more than 18.

[12] A means for brushing teeth according to one of paragraphs. [4] - [11] described above, where in the mixed granules the number of granules (a) according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering, is preferably at least 3 vol.%, More preferably at least 5 vol.%, Even more preferably not less than 7 vol.%, And preferably not more than 15 vol.%, More preferably not more than 12 vol.%, Even more preferably not more than 10 vol.%.

[13] A means for brushing teeth according to one of paragraphs. [4] - [12] described above, where in the mixed granules the number of granules (b) according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering, is preferably at least 12 vol.%, More preferably at least 15 vol.%, Even more preferably not less than 20 vol.% And preferably not more than 50 vol.%, More preferably not more than 40 vol.%, Even more preferably not more than 35 vol.%.

[14] A means for brushing teeth according to one of paragraphs. [4] - [13] described above, where in the mixed granules the number of granules (d) according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering, is preferably at least 5 vol.%, More preferably at least 10 vol.%, Even more preferably not less than 12 vol.%, And preferably not more than 25 vol.%, More preferably not more than 22 vol.%, Even more preferably not more than 20 vol.%.

[15] A dentifrice according to one of claims [4] - [14] described above, where the mixed granules contain granules (e) having a particle size of not less than 250 μm and not less than 350 μm, according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering, and the number of granules (e) is preferably more than 0 vol.%, more preferably not less than 1 vol.%, even more preferably not less than 2 vol.%, and preferably not more than 25 vol.%, more preferably not more than 20 vol.% , even more preferably not more than 18 vol.%.

[16] A means for brushing teeth according to one of paragraphs. [4] to [15] described above, wherein the fracture resistance of the mixed granules is preferably not less than 2 gs / granule, more preferably not less than 3 g / granule, and preferably not more than 15 g / granule, even more preferably not more than 10 gs / granule, even more preferably not more than 8 gf / granule.

[17] A means for brushing teeth according to one of paragraphs. [1] - [16] described above, wherein the content of water-insoluble powder material (A) in the mixed granules is preferably not less than 60 wt.%, More preferably not less than 70 wt.%, Even more preferably not less than 80 wt. %, even more preferably not less than 82 wt.% in the dry state, and preferably not more than 98 wt.%, more preferably not more than 96 wt.%, even more preferably 80 wt.% in the dry state.

[18] A means for brushing teeth according to one of paragraphs. [1] to [17] as described above, wherein the water-insoluble powder material (A) is preferably one or more substances selected from the group consisting of heavy calcium carbonate, light calcium carbonate, zeolite and silicon dioxide, more preferably heavy carbonate calcium.

[19] A dentifrice according to one of claims [1] - [18] described above, wherein the inorganic binder (B) contains one or two substances selected from the group consisting of sodium silicate and colloidal silicon dioxide, and the content of one or two substances selected from the group consisting of sodium silicate (dry matter content) and colloidal silicon dioxide in the inorganic binder (B) present in the mixed granules is preferably not less than 60 wt.%, more preferably not less than 80 wt.%, even more preferably not less than 90 wt.% , and preferably about no more than 100 wt.%.

[20] A dentifrice according to one of claims [1] - [19] described above, where the content of component (B), which is one or two substances selected from the group consisting of sodium silicate (dry matter content) and colloidal silicon dioxide, in the mixed granules is preferably not less than 1 wt.%, More preferably not less than 2 wt.%, Even more preferably not less than 5 wt.%, Even more preferably not less than 10 wt.%, And preferably not more than 30 wt.%, More preferably not more than 20 wt. %, even more preferably not more than 18 wt.% in the dry state.

[21] A means for brushing your teeth according to one of paragraphs. [1] - [20] described above, where the granules after mixing preferably contain one or more binders (C) selected from the group consisting of calcium silicate, magnesium oxide, titanium oxide and zinc oxide, and the content of the component (C ) is preferably not less than 0.2 wt.%, more preferably not less than 0.5 wt.%, even more preferably not less than 0.8 wt.%, and preferably not more than 5 wt.%, more preferably not more than 3 wt. %, even more preferably not more than 2 wt.%, even more preferably not more than 1.2 wt.% in dry TATUS.

[22] A means for brushing teeth according to one of paragraphs. [1] to [21] described above, wherein the amount of mixed granules is preferably not less than 1 wt.%, More preferably not less than 3 wt.%, Even more preferably not less than 5 wt.%, And preferably not more than 50 wt. %, more preferably not more than 30 wt.%, even more preferably not more than 20 wt.%.

[23] A means for brushing teeth according to one of paragraphs. [1] - [22] described above, where the mixed granules are preferably obtained by roller granulation, and also preferably obtained by adding unmixed granules to the dentifrice, followed by mixing the dentifrice with a speed of at least 10 rpm and not more 250 rpm

[24] A means for brushing teeth according to one of paragraphs. [1] to [23], described above, preferably further comprising a binding agent, more preferably additionally containing one or more binders selected from the group consisting of sodium carboxymethyl cellulose, xanthan gum and carrageenan.

[25] A dentifrice according to one of claims [1] to [24] described above,

where in unmixed granules before mixing to obtain mixed granules, among the following granules (b ’) - (e-1’) according to the particle size distribution, where the particle size distribution is determined by laser diffraction / scattering:

granules (b ’) have a particle size of at least 100 microns and less than 150 microns,

granules (c ’) have a particle size of at least 150 microns and less than 200 microns, and

granules (d ’) have a particle size of at least 200 microns and less than 250 microns, and

granules (e ’) have a particle size of at least 250 microns and less than 300 microns,

where the volume ratio of the number of granules (b ') to the number of granules (s'), (b' / s') is preferably not less than 0.6 and not more than 1.25, the volume ratio of the number of granules (d ') to the number of granules (c '), (d' / s'), is preferably not less than 0.7 and not more than 1.2, and the volume ratio of the number of granules (e-1 ') to the number of granules (c'), (e-1 '/ s'), is preferably not less than 0.4 and not more than 1.1.

[26] The dentifrice of [25] described above, wherein the fracture resistance of unmixed granules is preferably not less than 1 g / granule, more preferably not less than 2 g / granule, even more preferably not less than 3 g / granule, and preferably not more than 20 gf / granule, more preferably not more than 15 gf / granule, even more preferably not more than 10 gf / granule.

[27] A method for producing a dentifrice according to one of claims [1] - [26] described above, comprising the step of adding granules to the dentifrice after adding the binding agent and the step of mixing the dentifrice to which the granules were added at a speed of at least 10 rpm and not more than 250 rpm

Examples

The present invention is more specifically described below based on examples. In this regard, unless otherwise indicated in the tables, the amount of each component added refers to the total amount of each component present in the dentifrice (wt.%). In addition, each value of a physical indicator was measured using the following methods.

1: Method for measuring the average particle size of water-insoluble powder

The average particle size of the water-insoluble powder was measured on a laser diffraction / scattering analyzer to determine the particle size distribution (LA-920 manufactured by HORIBA, Ltd.), under conditions including a solvent representing water purified by ion exchange chromatography, a refractive index of 1.2, the circulation speed on the scale in position 4 and the mixing speed on the scale in position 3.

2: Sodium silicate dry matter content

2.5 g of the sample was introduced into an aluminum vessel with a diameter of 11.5 cm and dispersed with a pipette so that the drop represented a droplet having a diameter of about 5 to 10 mm (without dropping as much as possible). Then, the content of evaporating free water was determined using an infrared thermogravimetric moisture meter (manufactured by Kett Electric Laboratory, FD240) in the mode of measuring the moisture content at a temperature of 105 ° C, in automatic conditions (under which, when the rate of change of the detected value decreases within 0.05% in for 30 seconds, then a certain value was taken as the final determined value with the completion of the measurement), and the dry matter content was calculated by subtracting the content of evaporating free water.

3: Method for measuring particle size distribution and average particle size in unmixed granules

Particle size distribution and average particle size were measured using an aqueous solution prepared by diluting unmixed granules with purified water on an ion exchange filter to 5 wt.%. An aqueous solution prepared by diluting unmixed granules with water purified on an ion-exchange filter to 5 wt.% Was subjected to a mixer treatment (NPC-20 rotary mixer manufactured by NISSIN Corporation) in the following mode: 75 rpm, rotation in the horizontal direction for 2 hours so as to disperse the granules. Then, an aqueous solution containing granules dispersed in it was kept at room temperature (25 ° C) for one day. After aging, the aqueous solution was redispersed for 10 minutes on the above mixer, the aqueous solution was analyzed using a laser diffraction / scattering analyzer to determine the particle size distribution (Partica LA-950V2 manufactured by HORIBA, Ltd.) in the following mode: refractive index 1.2 , the circulation speed on a scale at position 5 and the stirring speed on a scale at position 3. In this regard, the solvent used was purified water on an ion exchange filter.

4: Projection surface area in mixed granules (S _A ), the largest diameter (D _L ), circle area with diameter D _L  (S _S ) and smallest diameter (D _S )

(i) The projection surface area of the mixed granules was measured using granules obtained by diluting the dentifrice with purified water to a solution concentration of 10 wt%, washing the solution with purified water using a 150 μm sieve according to JISZ8801-1, and then drying the remaining granules on a sieve at room temperature (25 ° C) for a day.

(ii) The area (S _A ), the largest diameter (D _L ) and the smallest diameter (D _S ) of the projection surface were measured by photographing using a KEENCE VH-5500 (100x magnification). The photographed digital image and software were used for analysis (WinROOF (Mitani CORPORATION)) to obtain the area (S _A ), the largest diameter (D _L ) and the smallest diameter (D _S ) on one projection surface of each granule. The average value was calculated from the data for 5-10 granules to obtain the values of area (S _A ), largest diameter (D _L ) and smallest diameter (D _S ) on one projection surface of each granule. Then, based on these data, we determined the ratio of the area on one projection surface of the granules (S _A ) to the circumference with the largest diameter (D _L ) on the projection surface (S _S ), (S _A / S _S ) and the ratio of the largest diameter (D _L ) to the smallest diameter (Ds), (D _L / Ds).

5: Method for measuring particle size distribution, average particle size and the number of mixed granules present in a dentifrice

(i) Dispersion of granules in an aqueous solution for measurement: an aqueous solution prepared by diluting a dentifrice with water purified on an ion-exchange filter to a concentration of 10 wt% was subjected to a mixer treatment (NPC-20 rotary mixer manufactured by NISSIN Corporation) in the following mode: 75 rpm, rotation in the horizontal direction, for 2 hours, so as to disperse the granules. Then, an aqueous solution containing granules dispersed in it was kept at room temperature (25 ° C) for one day. After aging, the aqueous solution was redispersed for 10 minutes on the above mixer, and then analyzed on a laser diffraction / scattering analyzer to determine the particle size distribution.

Following the same method as described in paragraph (i) in section 4, the granules were recovered.

(ii) Determination of particle size distribution, average particle size and quantity: the obtained powder and mixed granules were analyzed using a laser diffraction / scattering analyzer to determine the particle size distribution (Partica LA-950V2 manufactured by HORIBA, Ltd.) under conditions with an indicator refractive index 1.58, the circulation speed on a scale in position 5 and the stirring speed on a scale in position 5. The solvent used was water purified on an ion-exchange filter.

In this regard, according to the present invention, according to the particle size distribution, where the particle size distribution was determined on a laser diffraction / scattering analyzer, the number of granules in each particle size range from (a) to (e) ((a e ') was calculated , (e ')) (vol.%). In particular, with respect to each particle size range measured by laser diffraction, the number of granules in each size range was multiplied by the ratio of the particle size range to thereby calculate the number of granules (a) to (e). For example, when granules having a particle size of at least 45 microns and less than 51 microns are 0.2 vol.%, And granules with a size of at least 51 microns and less than 101 microns are 7.5 vol.% According to laser diffraction, the amount granules (a) will be 0.2 vol.% × 1 / (51 - 45) + 7.5 vol.% × (100 - 51) / (101 - 51), and the calculation result will be 7.4 vol. %

Production Example 1: Preparation of Unmixed A’-E ’Granules

A mixture of heavy calcium carbonate (manufactured by Calfine Co., Ltd., trade name: ACE-25, average particle size of about 3 μm) and each of the various binder excipients (C) were placed in a 75-liter drum granulator (ϕ 40 cm × L 60 cm), equipped with a baffle, so as to achieve the production of granules having the composition shown in table 1, while mixing the mixture under conditions including the speed of the rotating drum 30 rpm, the Froude number 0.2 and the angle of the drum 12, 6 °, sodium silicate (manufactured by Fuji Chemical Industry Co., Ltd., trade name: No. 3 sodium silicate: Na ₂ × 3SiO ₂ solution; dry matter content 38.5%, diluted in no more than 3 times the amount of water, 25 ° C) was sprayed and added to the mixture using a two-jet nozzle with external stirring (manufactured by Atomax Co., Ltd.), and the resulting mixture was granulated. In this regard, the batch size is 8 kg. The rate of addition of an aqueous solution of sodium silicate was 3.3 ml / min.

After spraying an aqueous solution of sodium silicate, the mixture was continuously stirred for 1 min and then discharged from a drum-type granulator and dried at 80 ° C for 90 min using an electric rack dryer to obtain unmixed A’-E ’granules.

The particle size distribution for the unmixed granules A’-F ’each is shown in Table 2, and the particle size distribution for the unmixed granules B’ is shown in Figure 1.

Table 1 Unmixed granules Granules A ' Granules B ' Granules C ' Granules D ' Granules E ' Granules F ' (A) Heavy Calcium Carbonate 85.0 90.1 94.5 90.5 90.5 - Silicic Anhydride - - - - - 100.0 (B) Sodium Silicate (dry matter content) - 8.9 4,5 8.9 8.9 - Colloidal silicon dioxide 12.0 - - - - - Sodium silicate - - - 0.6 - - (C) Magnesium oxide - - - - 0.6 - Zinc oxide - 1,0 1,0 - - - Titanium oxide 3.0 - - - - - Generally 100.0 100.0 100.0 100.0 100.0 100.0 (B) / (A) 0.14 0.0988 0.05 0.10 0.10 - (C) / (B) 0.25 0.11 0.22 0,07 0,07 - S _A '/ S _S ' 0.67 0.69 0.76 0.81 0.77 0.99 D _L '/ D _S ' 1,59 1,69 1,62 1,56 1,56 1.00

table 2 Unmixed granules Granules A ' Granules B ' Granules C ' Granules D ' Granules E ' Granules F ' The content of the granules (a ') (vol.%) Particle size: not less than 50 microns and less than 100 microns 8.1 12.9 9.1 7.1 13,4 2,5 The content of granules (vol.%) Particle size: not less than 100 microns and less than 150 microns 9.7 14,4 13,4 13.3 16.3 19.8 The content of the granules (c ') (vol.%) Particle size: not less than 150 microns and less than 200 microns 10.7 14.2 14.1 17.0 17,2 43.0 The content of the granules (d ') (vol.%) Particle size: not less than 200 microns and less than 250 microns 10.9 13.9 13.6 16,4 15,5 22.5 The content of the granules (e'-1) (vol.%) Particle size: not less than 250 microns and less than 300 microns 10.6 12,4 12,2 13,2 12.1 8.3 The content of the granules (e'-2) (vol.%) Particle size: not less than 300 microns and less than 350 microns 9.8 9.6 10.0 9.3 8.2 1,0 The content of granules having a particle size of at least 350 μm (vol.%) 40,2 22.6 27.6 23.7 17.3 2.9 Volumetric ratio (b '/ c') 0.91 1.01 0.95 0.78 0.95 0.46 Volumetric ratio (d '/ c') 1,02 0.98 0.96 0.96 0.90 0.52 Volumetric ratio (e'-1 / c ') 0.99 0.87 0.87 0.78 0.70 0.19 Volumetric ratio (e'-2 / c ') 0.92 0.68 0.71 0.55 0.48 0.02 Volumetric ratio (a '/ c') 0.76 0.91 0.65 0.42 0.78 0.06 Fracture Resistance (gf / granule) 6.9 4,5 3,1 9.2 11.5 13,2

[Examples 1-10 and comparative example 1]

Each component was added together with the obtained unmixed granules A'-F 'according to the composition shown in table 3, and mixed using a universal mixer (5XDMVV10-r manufactured by Dalton Co., Ltd.) with a stirring speed with a turn of 75 rpm and a rotational stirring speed of 200 rpm for 10 min, thereby obtaining a dentifrice in which mixed granules A-F, respectively, obtained from unmixed granules A'-F 'are present.

Then, each dentifrice was evaluated in accordance with the following method.

The results are shown in table 3.

Also, the particle size distribution for the mixed granules AF present in each dentifrice is given in Table 4; a graph of the particle size distribution for the mixed granules B present in the dentifrice of Example 1 is shown in FIG. 1 , and an image of granules B obtained by scanning electron microscopy (electron microscope: Hitachi S-4800) is shown in FIG. 2. In addition, a particle size distribution chart for the mixed granules F present in the dentifrice of comparative example 1 is shown in FIG. 3.

Test example 1: evaluation of the effectiveness of dental plaque removal (plaque removal indicator)

The cleaning effect was tested using the following unevenness model and plaque model using the following method to calculate the degree of plaque removal. The results are shown in table 3.

(Roughness Model)

An irregularity model was provided that included linear grooves having an angle of 90 °, a width of 100 μm and a depth of 100 μm, arranged in parallel with an interval of 620 μm on a stainless steel plate 15 mm long × 15 mm wide × 3 mm deep.

 (Plaque model)

As a model of plaque, red chalk was used (manufactured by PENTEL CO., LTD., CRAYON RED) and rubbed onto whole grooves in the above model of irregularities, so that the grooves were filled with chalk. A flat spatula surface was drawn along the surface of the roughness model in order to remove model spots protruding from the surface of the roughness model and model spots adhering to the surface.

(Toothbrush Test)

The above model of irregularities was placed in rectangular recesses 15 mm long × 15 mm wide × 3 mm deep in the center of an aluminum plate (30 mm × 80 mm × 5 mm), and a toothbrush cleaning test was performed using 2 g of each dentifrice and toothbrush brushes (Deep Clean Compact manufactured by Kao Corporation) under cleaning conditions, including a load of 200 g, a toothbrush speed of 80 rpm and a number of movements of 30 mm / min in the direction of brushing teeth parallel to the grooves on the model of irregularities. In this regard, in the corner of the rectangular recess on the aluminum plate, a recess was provided for scraping the outside of the rectangle for easy removal of the model of irregularities.

(Method for calculating plaque removal rate)

After cleaning, the roughness model was removed from the aluminum plate and washed with water. Then, the dentifrice adhering to the surface of the roughness model was removed by holding a paper sheet (PPC paper, A4 size, KOKUYO Co., Ltd), pressing on the surface of the roughness model.

The roughness model before brushing and the roughness model after removing the dentifrice were photographed using a digital camera. The area of the area stained with chalk on the roughness model before cleaning was taken as the value of the area of the stained area (mm ² ). Also, the area of the area cleaned with a toothbrush in the stained area was taken as the area of the evaluation area (mm ² ), and the area of the area from which the crayon was removed, exposing the bottom of the recess (bleached area) (mm ² ) in the evaluation area, was taken as the area stain removal. Then, the area of the area from which the spots were removed was calculated with respect to the entire area of the evaluation area using the following formula (1) and the obtained value was used as an indicator of stain removal (%). In this regard, the area of the painted area represents the area of the area where the coloring was noted with pseudo-spot material when photographing with a digital camera. In this area, the toothbrush-cleaned area was taken as the evaluation area.

Stain removal rate (%) = (area with stains removed / total area of the assessment area) × 100 ... (1)

In this regard, the chalk deposited on the recesses in the test plate was removed by exposing the surface of the test plate when a certain pressure was applied, even when the flat surface was cleaned only with a toothbrush. A flash was used for digital camera photography, and a polarizing filter was used to remove light reflected from the surface.

Test example 2: assessment of the sensation of using a dentifrice

A toothbrush was brushed with 1 g of each of the various dentifrices obtained in Examples 1-10 and Comparative Example 1 using a toothbrush (Check Standard manufactured by Kao Corporation), and foam formation, foam quality (thinness of the foam) were evaluated, the stability of the foam during brushing, the feeling of the presence of granules at an early stage of brushing, the feeling of smoothness of the tooth surface immediately after brushing, and the preservation of the sensation of the presence of granules during brushing based on the criteria presented below. Foaming, the quality of the foam, the feeling of the presence of granules at an early stage of brushing, and the feeling of smoothness immediately after brushing were evaluated on a five-point scale from 1 to 5. This assessment was carried out by five experts to establish average values from the results.

In this regard, regarding the stability of the foam during brushing and maintaining the feeling of the presence of granules during brushing according to the above scale, the number of experts from five members of the commission who answered that the foam or sensation persisted was counted. The results are shown in table 2.

Foaming

5: Foam is very good

4: Foam is good

3: foam

2: It is hard to foam

1: Does not foam.

Foam quality (foam fineness)

5: The feeling that the foam is very thin

4: The feeling that the foam is thin

3: The feeling that the foam is a little thin

2: The feeling that the foam is a little rough

1: Feeling that the foam is coarse.

The feeling of the presence of granules in the early stages of brushing

5: The appropriate presence of granules is felt

4: The presence of granules is felt

3: A slight presence of granules is felt

2: A very slight presence of granules is felt

1: The presence of granules is not felt.

Sensation of smoothness of the tooth surface immediately after brushing

Sensation when the tongue is drawn along the surface of the teeth immediately after brushing the teeth (after washing off the dentifrice with water)

5: Very smooth surface and no plaque felt

4: Smooth surface and plaque hardly felt

3: Slightly smooth surface, but plaque is felt

2: Irregularities are slightly noticeable, and a slight plaque is felt

1: Irregularities are felt due to plaque on the surface of the teeth.

Table 3 Component Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Example 6 Example 7 Example 8 Sodium Monofluorophosphate 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7 Benzethonium chloride 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 Liquid sorbitol 30,0 30,0 30,0 30,0 30,0 30,0 30,0 30,0 30,0 Propylene glycol 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 - Polyethylene glycol 600 - - - - - - - - 3.0 Granules A 12.0 - - - - - - - - Granules B - 12.0 - - - - 5,0 25.0 12.0 Granules C - - 12.0 - - - - - - Granules D - - - 12.0 - - - - - Granules E - - - - 12.0 - - - - Granules F - - - - - 12.0 - - - Calcium carbonate 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 - Thickener 7.5 7.5 7.5 7.5 7.5 7.5 8.0 6.5 7.0 Sodium carboxymethyl cellulose A ^{* 1} 1,5 1,5 1,5 1,5 1,5 1,5 1,5 1,5 0.8 Sodium carboxymethyl cellulose B ^{* 2} - - - - - - - - - Carrageenan - - - - - - - - - Xanthan gum - - - - - - - - 0.2 Sodium Lauryl Sulfate 1,5 1,5 1,5 1,5 1,5 1,5 1,5 1,5 1,5 Perfume 1,0 1,0 1,0 1,0 1,0 1,0 1,0 1,0 1,0 Saccharin Sodium 0.14 0.14 0.14 0.14 0.14 0.14 0.14 0.14 0.15 PH regulating agent ^{* 3} q.s. q.s q.s q.s q.s. q.s. q.s. q.s. q.s. Purified water Balance Balance Balance Balance Balance Balance Balance Balance Balance Generally 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 Plaque removal rate 66.9 67.5 59.0 46.8 72.3 25.8 46.8 72.3 Foaming 4.2 4,5 four 3,5 3.3 2 3.4 4.3 4,5 Foam quality (foam fineness) four 4.6 4.2 3.3 3,5 2.1 4.1 4,5 4.6 Stability of the foam during brushing 5 5 3 3 3 one 3 5 5 The feeling of the presence of granules at the stage of brushing 4.3 4.3 3.9 4,5 4,5 2.1 3.2 4.6 4.3 Sensation of smoothness immediately after brushing your teeth 4.4 4.6 3.4 4.3 4.4 2.1 3,5 4.6 4.6 Preservation of the feeling of the presence of granules during brushing four 5 3 four four one 3 5 5 * 1: CMC1205 (manufactured by Diacel Chemical Industries, LTD.)
* 2: SUNROSE F35H (manufactured by Nippon Paper Industries Co., Ltd.)
* 3: sodium hydrogen phosphate and sodium dihydrogen phosphate: a total of 2.5 wt.%

Table 4 Mixed granules Granules A Granules B Granules C Granules D Granules E Granules F The content of the granules (a) (vol.%) Particle size: not less than 50 microns and less than 100 microns 8.1 8.7 8.6 8.9 6.7 5.3 The content of the granules (b) (vol.%) Particle size: not less than 100 microns and less than 150 microns 15.6 27.6 34.3 29.6 19.5 17.4 The content of the granules (c) (vol.%) Particle size: not less than 150 microns and less than 200 microns 16.1 33.8 41.5 32,4 24.5 28,2 The content of the granules (d) (vol.%) Particle size: not less than 200 microns and less than 250 microns 12.9 17.0 12.8 15.4 18,4 23,2 The content of the granules (e) (vol.%) Particle size: not less than 250 microns and less than 350 microns 17.3 10.1 2,8 10,2 18,4 20.8 The content of granules having a particle size of at least 350 μm (volume%) 30,0 2,8 0,0 3,5 12.5 5.1 Volumetric ratio (b / c) 0.97 0.82 0.83 0.91 0.80 0.62 Volumetric ratio (d / c) 0.80 0.50 0.31 0.48 0.75 0.82 Volumetric ratio (b / d) 1.21 1,62 2.68 1.92 1.06 0.75 Volume ratio ((a + b) / (c + d)) 0.82 0.71 0.79 0.81 0.61 0.44 Volume ratio ((a + b) / e) 1.37 3,59 15.32 3.77 1.42 1.09 S _A / S _S 0.79 0.78 0.80 0.89 0.81 0.99 D _L / D _S 1.42 1,60 1,59 1.32 1.48 1.00 Fracture Resistance (gf / granule) 6.9 4,5 3,1 9.2 11.5 13,2 The average volumetric particle size (μm) 201 169 157 167 199 202

From the above results, it becomes apparent that the dentifrices of Examples 1-10 provide an excellent sensation of use compared to the dentifrice of Comparative Example 1.

Reference List

X: particle size distribution for unmixed granules B ’

Y: particle size distribution for mixed granules B.

Claims (12)

1. A dentifrice containing mixed granules obtained by adding unmixed granules containing water-insoluble powder material (A) and an inorganic binder containing one or two substances selected from the group consisting of sodium silicate and colloidal silicon dioxide (B ), in a dentifrice followed by mixing of a dentifrice with a speed of at least 10 rpm and not more than 250 rpm, where in mixed granules in a dentifrice, the average value of the ratio of the area of the projection surface of the granules (SA) to the circle area whose diameter represents the largest transverse diameter (DL) of the projection surface (SS), (SA / SS) is at least 0.5 and not more than 0.9 and the fracture resistance of the mixed granules is not less than 1 gf / granule and not more than 20 gf / granule, and where the number of mixed granules in the dentifrice is not less than 1 wt.% and not more than 50 wt.%, where unmixed granules that are used to add to the dentifrice to obtain mixed granules in the dentifrice are obtained by roller granulation, and among the following unmixed granules (b ') - (e-1'), according to the particle size distribution as determined by laser diffraction / scattering: granules (b ’) have a particle size of at least 100 microns and less than 150 microns, granules (c ’) have a particle size of at least 150 microns and less than 200 microns, and granules (d ’) have a particle size of at least 200 microns and less than 250 microns, and granules (e-1 ’) have a particle size of at least 250 microns and less than 300 microns, where the volume ratio of the number of granules (b ') to the number of granules (s'), (b' / s') is not less than 0.6 and not more than 1.25, the volume ratio of the number of granules (d ') to the number of granules ( s '), (d' / s '), is not less than 0.7 and not more than 1.2, and the volume ratio of the number of granules (e-1') to the number of granules (c '), (e-1' / c '), is not less than 0.4 and not more than 1.1, and the fracture resistance of unmixed granules is not less than 1 gf / granule and not more than 20 gf / granule. 2. The dentifrice according to claim 1, where in the mixed granules in the dentifrice the average ratio of the largest diameter (DL) to smallest diameter (DS) on the projection surface of the mixed granules (DL / DS) is at least 1.2 and no more than 1.8. 3. The dentifrice according to claim 1, wherein the granules contain one or more binders (C) selected from the group consisting of calcium silicate, magnesium oxide, titanium oxide and zinc oxide. 4. The dentifrice according to claim 3, wherein in the mixed granules in the dentifrice the mass ratio of component (C) to component (B) in the granules (C / B) is at least 0.02 and not more than 1.

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