JP6189651B2 - Dentifrice - Google Patents

Description

  The present invention relates to a dentifrice containing specific granules.

  Conventionally, dentifrices containing granules are known in order to improve the feeling of use by improving the tactile sensation in the mouth and to easily recognize the effect of removing dirt. As such a granule, what has various characteristics is used according to a desired use and performance.

  For example, Patent Document 1 discloses a dentifrice containing granules having a deformation rate of 0.1 to 20% within a range of 0.1 to 50 g per particle. It is described that it is highly palpable in the mouth and suppresses discomfort such that granules adhere to the teeth and become clogged. Further, Patent Document 2 discloses a dentifrice containing a wet process silica granule having an RDA value of 150 or less, which enables palpation of the granule in the oral cavity and can reduce the feeling of foreign matter while recognizing the dirt removing effect. It is described.

Under these circumstances, as a dentifrice containing granules in recent years, a sufficient cleaning effect between the surfaces of teeth and between teeth rather than increasing the palpability of the granules in the oral cavity as described in Patent Documents 1 and 2 It is strongly demanded to be able to demonstrate. For example, in Patent Document 3, the color removal performance is improved by containing specific granules and abrasive powder. Patent Document 4 also describes that the removal performance of plaque or dirt on the tooth surface and the gap between teeth can be improved by containing spherical wet-process silica granules having a deformation rate of 12 to 30%. Has been.
On the other hand, in dentifrices containing these granules, if tooth stains such as dental plaque can be sufficiently removed even if the brushing pressure is reduced, the burden on the user during brushing will be reduced and the range of use will be greatly expected. The

JP-A-4-243815 Japanese Patent Laid-Open No. 9-12436 JP 10-316547 A JP 2010-275260 A

  However, when the load during normal brushing for adults is assumed to be about 200 g, in Patent Document 3, such a dentifrice is only evaluated by brushing under a load as high as 600 g by evaluating the colorant removal power of the dentifrice. Furthermore, sufficient examination has not been made as to whether or not an excellent removal force can be exhibited even when the load is lowered. Further, even the dentifrice of Patent Document 4 requires further improvement in order to exhibit sufficient dirt removal performance even when the load during brushing is reduced or the brushing time is shortened.

  Therefore, the present invention relates to a dentifrice excellent in dirt removal performance that can sufficiently remove plaque and dirt on the teeth even by brushing with a reduced load.

  Therefore, the present inventors have found that a dentifrice that exhibits high dirt removal performance can be obtained even by brushing under a low load by using granules having a specific average particle diameter and a high deformation rate. I found it.

That is, the present invention has an average particle size of 100 μm or more and 300 μm or less, and when one granule is collapsed by applying compression at a load rate of 1.51 g / sec (Formula 1):
Deformation rate (%) = (Displacement in compression direction at the time of collapse / particle diameter before compression) × 100 (Equation 1)
It is related with the dentifrice containing the granule whose deformation rate of the particle | grains of a compression direction represented by these is 35% or more and 70% or less.

  According to the dentifrice of the present invention, since it contains granules that can be easily deformed even by brushing under a low load, a narrow portion such as a gap between teeth is combined with having an appropriate average particle size. It is possible to effectively remove plaque and dental stains while intertwining with some of the granules that are effectively invading and gradually disintegrating. Therefore, it is possible to exert high dirt removal performance while reducing the burden on the user even by brushing a child or an elderly person with weak brushing power. In addition, effective brushing while reducing the burden of contact with the gingiva, even on sensitive and soft parts such as the gums of children, or in the oral cavity affected by periodontal disease, gingivitis, etc. can do.

It is a figure which shows the concept of a dental plaque or dirt removal effect evaluation model. It is a figure which shows the model plaque removal effect of the dentifrice of Examples 1, 4 and Comparative Example 1.

Hereinafter, the present invention will be described in detail.
The dentifrice of the present invention has an average particle size of 100 μm or more and 300 μm or less, and collapses by applying compression at a load rate of 1.51 g / sec to one granule (Formula 1):
Deformation rate (%) = (Displacement in compression direction at the time of collapse / particle diameter before compression) × 100 (Equation 1)
A granule having a deformation rate of 35% to 70% in a compression direction represented by The granule used in the present invention has an appropriate average particle size and the above-described specific deformation rate that enables high deformation even by brushing under a low load. Therefore, if the dentifrice of the present invention containing such granules is used, the granules effectively invade into a narrow site such as a gap between the teeth and the teeth, and the contact area between the granules and the tooth surface increases. Excellent dirt removal performance can be exhibited.

  The average particle size of the granule used in the present invention is 100 μm or more, preferably 150 μm or more, from the viewpoint of easily applying a load due to brushing to the granule and improving the dirt removal performance between the teeth. . The average particle diameter of the granule is 300 μm or less, preferably 250 μm or less, from the viewpoint of easy penetration into the gap between the teeth and suppression of the feeling of foreign matter. Moreover, the average particle diameter of the said granule is 100-300 micrometers, Preferably it is 150-250 micrometers. The average particle size of the granule of the present invention is a weight integrated distribution when the particle size is measured by a sieving method, for example, using a sonic sieve (Tsukui Rika Instruments, program-controlled sonic sieve SW-20AT). A value of 50% is meant. In addition, the particle size distribution of the granule of the present invention is preferably 75 to 500 μm from the balance between the viewpoint of easily applying a load due to brushing to the granule, and the viewpoint of combining high dirt removal performance with the viewpoint of suppressing foreign matter feeling. Preferably it is 100-500 micrometers.

  The deformation rate of the granules used in the present invention is 35% or more from the viewpoint of enabling deformation with a high degree of freedom to easily follow the shape of such a part even in a narrow part in the oral cavity, and preferably 40%. % Or more, more preferably 45% or more. The deformation rate of the granules is 70% or less, preferably 67% or less, from the viewpoint of effectively entangled with some of the gradually disintegrating granules and effectively increasing the contact area between the granules and the tooth surface. More preferably, it is 65% or less. The deformation rate of the granules is 35 to 70%, preferably 40 to 67%, and more preferably 45 to 65%.

The deformation rate of the granule used in the present invention is as follows: for a wet granule, the granule disintegrates when one granule is compressed by a compression tester (Shimadzu Corporation, MCTM-500) at a load rate of 1.51 g / sec. The displacement of the particles in the compression direction at that time is divided by the particle size before compression, and is expressed by (Equation 1).
Deformation rate (%) = (Displacement in compression direction at the time of collapse / particle diameter before compression) × 100 (Equation 1)
The granule used in the present invention is a granule having such a deformation rate having a value within the specific range. Specifically, the deformation rate is defined by the particle diameter A before compression for each granule and the length in the compression direction when the granule is collapsed by compression: the particle diameter B, {(particle diameter A deformation rate (%) calculated by A−particle diameter B) / particle diameter A} × 100 is calculated, and is a value confirmed for 5 to 50 granules. In addition, the deformation rate of the granule mix | blended with the dentifrice is extracted from a dentifrice, wash | cleaned with purified water, and measures it in a wet state, without making it dry. Since the physical properties of the granule of the present invention change due to cracks and the like when dried, measurement is performed without drying. Note that the deformation rate is 35% or more and 75% or less even in an appropriate water-containing state before blending with the dentifrice immediately after production or in a state wet with water.

  The disintegration strength of the granules used in the present invention is preferably 1 gf / piece or more, more preferably 2 gf, when measured in a wet state, from the viewpoint of further enhancing the soil removal performance while being entangled with the gradually deforming and deforming granules. / Piece or more, more preferably 3 gf / piece or more. The disintegration strength of the granule is preferably 20 gf / piece or less, more preferably 15 gf / piece, from the viewpoint of imparting moderate disintegration even by brushing under a low load, and from the viewpoint of suppressing a sense of discomfort and foreign matter. Or less, more preferably 10 gf / piece or less. Moreover, the disintegration strength of the granule is preferably 1 to 20 gf / piece, more preferably 2 to 15 gf / piece, and further preferably 3 to 10 gf / piece.

  Here, the disintegration strength of the granule used in the present invention is a disintegration by compressing a granule having a particle size (185 to 215 μm) at a load speed of 1.51 gf / sec using a compression tester (Shimadzu Corporation, MCTM-500). It is a load when it is measured, and is an average value measured for 10 to 20 granules. In addition, the disintegration strength of the granules used in the present invention is the strength in a wet state, and it is estimated that the same strength is obtained even when blended in a toothpaste (wet state). That is, when a dentifrice is used, it is preferably 1 to 20 gf / piece, more preferably 2 to 15 gf / piece, from the viewpoint of further enhancing the dirt removal performance while being entangled with granules that gradually collapse and deform. Preferably, it has a disintegration strength in a wet state of 3 to 10 gf / piece.

The filling density of the granule used in the present invention is preferably 0.6 g / cm ³ or more, more preferably 0.00 g / cm ³ or more in the state before blending into the dentifrice, from the viewpoint of imparting a high deformation rate as described above. It is 63 g / cm ³ or more, more preferably 0.65 g / cm ³ or more. From the viewpoint of effectively increasing the contact area between the granule and the tooth surface, the packing density of the granule is preferably 1. 0 g / cm ³ or less, more preferably 0.95 g / cm ³ or less, and even more preferably 0.9 g / cm ³ or less. The packing density of the granules is preferably 0.6 to 1.0 g / cm ³ , more preferably 0.63 to 0.95 g / cm ³ , and further preferably 0.65 to 0.9 g. / Cm ³ . In addition, about the packing density of the granule in a dentifrice, it shall obtain | require from what extracted the granule, wash | cleaned with water, and remove | excluded the moisture of the granule surface by natural drying etc.

  The granule used in the present invention preferably has a spherical shape of 70 to 100%, more preferably 80 to 100, from the viewpoint of efficiently transmitting a load applied while maintaining appropriate disintegration to the tooth surface. % Is spherical, and more preferably 90 to 100% is spherical. Whether or not it is spherical refers to a generally smooth spherical shape having no depressions or protrusions whose overall shape cannot be determined as a spherical shape, and means that the diameters in the vertical direction and the width direction are approximately equal visually. In addition, when it is recognized that the granule is missing due to mixing or the like, the overall shape is determined by a virtual surface supplemented with the missing portion, and the spherical shape is determined when the overall shape is determined to be spherical. Then, the number of granules judged to be spherical is obtained from a plurality of visually observed (50 to 100) granules, and the ratio is calculated. Specifically, when a plurality of granules are sampled at random and visually observed 200 to 300 times with a microscope (for example, KEYENCE, digital high-definition microscope), it is determined that the surface is a smooth sphere or missing. When the missing portion is covered with a virtual surface, the ratio (%) of the number of granules judged to be spherical to the total number of granules is obtained. Whether or not the chip is missing is determined from the fact that the surface state of the chipped portion is not smooth.

In the production of the granules, the materials used include, for example, silica, aluminum hydroxide, magnesium phosphate, calcium carbonate, calcium pyrophosphate, zeolite, composite aluminosilicate, magnesium carbonate, dicalcium phosphate, tricalcium phosphate, insoluble metalin Examples include sodium acid. These may be used alone or in combination of two or more. Among these, from the viewpoints of imparting a high deformation rate and improving dirt removal performance, and handling and versatility, one or more selected from silica, calcium carbonate, aluminum hydroxide and zeolite are preferred. More preferably, it is silica.
In addition to the above materials, granules may be produced by using a binder, a fragrance, a colorant, an excipient and the like in combination.

  The granules used in the present invention are preferably those using silica as a material, that is, silica granules, from the viewpoint of imparting the above deformation rate while having an appropriate average particle size. Such silica granules are preferably produced by a wet gelling method. In the production by a wet gelation method, synthesis is performed by a neutralization reaction between an alkali metal silicate and an inorganic acid, and sodium silicate and sulfuric acid are generally used.

  Specifically, the wet gelation method includes a step of mixing an alkali metal, a silicate, and an inorganic acid to form a silica sol, a step of gelling the silica sol to obtain a silica hydrogel, and the obtained silica hydrogel Is carried out by a production method including a step of adjusting the water content.

  To illustrate in more detail, the step of mixing the alkali metal, silicate, and inorganic acid to produce a silica sol pumps the aqueous solution of alkali metal silicate into the mixing nozzle at a constant flow rate, while maintaining the inorganic acid constant. A step of pumping to the mixing nozzle at a flow rate; Thereby, in the mixing nozzle, the alkali metal silicate aqueous solution and the inorganic acid are stirred and mixed, and as a result, a silica sol is generated and gelled to obtain a silica hydrogel. As an alkali metal silicate used by this invention, 1 or more types chosen from sodium silicate, potassium silicate, ammonium silicate, etc. are mentioned, Sodium silicate is preferable from an industrial viewpoint. Moreover, as an inorganic acid, 1 or more types chosen from a sulfuric acid, nitric acid, hydrochloric acid, phosphoric acid, carbonic acid, etc. are preferable, and a sulfuric acid is preferable from an industrial viewpoint.

Furthermore, it is preferable to provide the process of spheroidizing a silica hydrogel. The step of spheroidizing the silica hydrogel can include, for example, the following method in the step of obtaining the silica hydrogel by gelling the silica hydrosol.
(1) A method of obtaining silica hydrogel by suspending or emulsifying silica sol in a solvent and gelling in a suspension or emulsion. That is, the spherical silica gel can be produced also by a method in which a silica sol, whose pH is adjusted in advance, is suspended in a solvent such as an oil having no affinity for it and gelled in the suspension. For example, there is a method for producing spherical silica particles in which an adjusted silica sol is emulsified in an organic solvent such as toluene or xylene using an emulsifier and gelled in the obtained emulsion. Further, there is a method for producing silica gel, characterized in that an alkali metal silicate aqueous solution is stirred in the organic solvent to form fine droplets, and then the droplets are gelled with carbon dioxide gas.
(2) A method of forming silica hydrogel by spraying silica sol. That is, it is a method in which silica sol is dispersed in air at a constant flow rate to form droplets and then gelled. For example, an alkali silicate solution and an inorganic acid are continuously supplied separately by a rotating disk spray device, etc., and dispersed as droplets of a mixed solution of an alkali silicate solution and an inorganic acid, and the droplets are gelled during the scattering. There is a method for producing spherical silica gel.
The spheroidization of the silica hydrogel may be performed by any of these methods.

  Then, it is preferable to provide the process of hydrothermally treating in 80 degreeC or more in alkaline aqueous solution of pH 8.0 to pH 9.5. The hydrothermal treatment temperature is preferably 200 ° C. or lower, more preferably 150 ° C. or lower. The hydrothermal treatment time is preferably 8 to 12 hours. Further, the hydrothermal treatment step may include two steps. For example, after the first hydrothermal treatment step at 90 ° C. for 8 hours, 0.1 MPa (100 ° C.) to 0.6 MPa (160 ° C.), 1 to 4 You may provide the process of the time 2nd hydrothermal treatment. As the alkali source, any of sodium hydroxide, potassium hydroxide, ammonia and the like may be used, but ammonia is preferable. Hydrothermal treatment can increase the strength of the bonding sites between the colloidal silica particles by dissolution and precipitation of the colloidal silica particles constituting the spherical silica hydrogel, and can stabilize the structure of the spherical silica hydrogel and increase the collapse strength. Further, by adjusting the pH to 8.0 to 9.5, it is possible to prevent generation of amorphous particles and decrease in yield due to dissolution and aggregation of the hydrogel.

  The process of adjusting the water content of the silica hydrogel varies depending on the apparatus, but the temperature is 40 to 300 ° C., the treatment time is adjusted under the conditions of 1 second to 60 minutes, and the water content of the silica hydrogel after the water content adjustment is 50% to 80%. Adjust to. By such a water content adjustment step, loss of flexibility of the silica hydrogel can be suppressed, and silica granules having a high deformation rate can be obtained effectively as granules for the dentifrice composition. From this viewpoint, the water content of the silica hydrogel after the water content adjusting step is 50% or more, preferably 55% or more, 80% or less, and preferably 75% or less. The water content means the mass of water in the total mass of the silica hydrogel.

  In the step of adjusting the water content of the silica hydrogel, a box-type drying device, a rotary-type drying device, a fluidized bed drying device, an airflow drying device, or the like is generally used. In the step of adjusting the water content, from the viewpoint of maintaining a constant deformation rate and collapse strength, when using a stationary drying device such as a box-type drying device, the silica hydrogel is water-containing at a temperature of 40 to 300 ° C. for 1 to 60 minutes. It is preferable to adjust, and when using a fluid mixing type drying apparatus such as a rotary type drying apparatus or a fluidized bed drying apparatus, a residence time of 1 to 15 minutes at a temperature of 40 to 300 ° C. is obtained. It is preferable to adjust the water content of the hydrogel.

  When a box-type, rotary type or fluidized bed drying apparatus is used, there is an advantage that the yield of the product is improved by suppressing the occurrence of cracking because there is little movement of the product at the time of water content adjustment. The airflow drying apparatus is an apparatus suitable for mass processing, and the desired performance can be obtained by adjusting the water content of the silica hydrogel by contact with heated air at 60 to 300 ° C. for 1 to 60 seconds. Although there is a tendency for cracks to increase when using an air-flow dryer, the amount of cracks in the spherical silica hydrogel is reduced by controlling the air volume of the heated air and making the moving speed in the tube 20 m / s or less. Performance can be obtained.

  Furthermore, a method of adjusting the water content by uniformly contacting an adsorbent such as silica xerogel can also be used. For example, a silica xerogel having a high moisture adsorbing ability is used in the water content adjustment step, and the spherical silica hydrogel and the water content adjustment silica xerogel are uniformly mixed by an air transport type powder and particle mixing device to adjust the water content. The contact time is preferably 15 minutes or longer, more preferably 20 minutes or longer, and the contacting method is not limited as long as it uses a device that can be uniformly mixed. Examples of such an apparatus include a fixed container type mixing apparatus, a container rotating type mixing apparatus, and a fluid motion type mixing apparatus.

  The silica granules obtained by the water content adjustment step are classified with a sieve. It is desirable that the classified silica granules have a particle size that passes through 600 μm, more preferably passes through 425 μm, but does not pass through 100 μm. Thereby, silica granules having an average particle diameter of 100 to 300 μm can be obtained.

  The granulation method of the granule is not particularly limited, and tumbling granulation, extrusion granulation, compression granulation, crushing granulation, stirring granulation, fluidized bed granulation, spray drying granulation, melt solidification granulation It is also possible to use a known method such as

  The content of the granule is preferably 1% by mass or more, more preferably 1.2% by mass or more, and still more preferably 1% in the dentifrice of the present invention from the viewpoint of improving dirt removal performance. 0.5% by mass or more, and more preferably 1.7% by mass or more. The content of the granule is preferably 5% by mass or less, more preferably 4.7% in the dentifrice of the present invention, from the viewpoint of suppressing the foreign substance feeling in the oral cavity while ensuring excellent dirt removal performance. It is not more than mass%, more preferably not more than 4.5 mass%. Further, the content of the granule is preferably 1 to 5% by mass, more preferably 1.5 to 4.7% by mass, and further preferably 1.7 to 4% in the dentifrice of the present invention. 0.5% by mass.

Further, the dentifrice of the present invention is a granule in a form different from the above-mentioned granule as a powder of an abrasive of a dentifrice usually used in a dentifrice base material, as long as the effects of the present invention are not impaired. Can be used together. Commonly used dentifrice abrasives include, for example, dicalcium phosphate, tricalcium phosphate, insoluble sodium metaphosphate, abrasive silica other than the above granules, aluminum hydroxide, magnesium phosphate, calcium carbonate, calcium pyrophosphate, zeolite , Composite aluminosilicate and magnesium carbonate. These may be used alone or in combination of two or more. Among these, from the viewpoint of high cleaning effect and high handleability and versatility, one or more selected from calcium carbonate, abrasive silica, aluminum hydroxide, and zeolite are preferable, and abrasive silica is more preferable.
In general, the abrasive used for the dentifrice, unlike the granule of the present invention, generally has a particle size of less than 50 μm and at most a particle size of less than 75 μm. Further, the powder as an abrasive has a disintegration strength of 30 gf / piece or more, a deformation rate represented by the above formula (1) of 5% or less, and at most 10% or less.

  The content of water in the dentifrice of the present invention can be appropriately set according to the dosage form, etc., but improves the dispersibility of the granules and other components, and has excellent dirt removal performance and good tactile sensation. In the dentifrice of the present invention, it is preferably more than 0% by mass, more preferably 10% by mass or more from the viewpoint of effectively exhibiting. The content of water is preferably 60% by mass or less, more preferably 50% by mass or less in the dentifrice of the present invention from the viewpoint of efficiently transmitting a load to be applied. Moreover, the content of water in the dentifrice of the present invention is preferably more than 0% by mass and 60% by mass or less, and more preferably 10 to 50% by mass.

  The water content (moisture content) in the dentifrice of the present invention can be calculated from the blended moisture content and the moisture content in the blended component, but can be measured, for example, with a Karl Fischer moisture meter. . As the Karl Fischer moisture meter, for example, a trace moisture measuring device (manufactured by Hiranuma Sangyo Co., Ltd.) can be used. In this apparatus, 5 g of dentifrice is taken and suspended in 25 g of anhydrous methanol, and 0.02 g of this suspension is fractionated and the amount of water can be measured.

  In the dentifrice of the present invention, in addition to the above components, for example, a binder such as sodium alginate, sodium carboxymethylcellulose, carrageenan, xanthan gum; glycerin, sorbitol, propylene glycol, xylitol, Wetting agents such as maltite, lactit, trehalose; sweeteners such as saccharin sodium and aspartame; preservatives such as ethyl paraoxybenzoate; pH adjusters such as phosphoric acid, citric acid, malic acid and their salts; Anionic surfactants such as phosphate, alkyl sulfate ester salt, fatty acid ester salt, N-methyl long chain acyl taurine sodium salt, polyoxyethylene monoalkyl phosphate; sucrose fatty acid ester, polyoxyethylene hydrogenated castor oil, Poly Nonionic surfactants such as lysine fatty acid ester and sorbitan fatty acid ester and other surfactants; sodium fluoride, tin fluoride, ammonium fluoride, potassium fluoride, lithium fluoride, sodium monofluorophosphate, monofluorophosphate Fluorine ion supply compounds such as potassium and ammonium fluoride; allantoin, tranexamic acid, vitamin E, vitamin C, sodium chloride, sodium fluoride, sodium monofluorophosphate, benzethonium chloride, glycyrrhetinic acid, chlorhexidine, cetylpyridinium chloride, trichlorohydroxy Medicinal components such as phenyl ether (triclosan); perfume and the like can be appropriately contained.

  The dentifrice of the present invention can be various dentifrices such as toothpaste and toothpaste. Of these, it is preferable to use a toothpaste from the viewpoint of effectively realizing excellent dirt removal performance by granules and good tactile properties in the oral cavity.

In relation to the embodiment described above, the present invention further discloses the following dentifrice.
[1] When the average particle size is 100 μm or more and 300 μm or less and one granule is collapsed by applying compression at a load rate of 1.51 g / sec (Formula 1):
Deformation rate (%) = (Displacement in compression direction at the time of collapse / particle diameter before compression) × 100 (Equation 1)
The dentifrice containing the granule whose deformation rate of the particle | grains of compression direction represented by these is 35% or more and 70% or less.
[2] The dentifrice of [1] above, wherein the average particle diameter of the granules is preferably 150 μm or more, and preferably 250 μm or less.
[3] The deformation rate of the granule is preferably 40% or more, more preferably 45% or more, preferably 67% or less, and more preferably 65% or less, [1] or [2] Dentifrice.

[4] The disintegration strength of the granules is preferably 1 gf / piece or more, more preferably 2 gf / piece or more, further preferably 3 gf / piece or more, preferably 20 gf / piece or less, more preferably The dentifrice according to any one of the above [1] to [3], which is 15 gf / piece or less, more preferably 10 gf / piece or less.
[5] The packing density of the granules is preferably 0.6 g / cm ³ or more, more preferably 0.63 g / cm ³ or more, further preferably 0.65 g / cm ³ or more, preferably 1 .0g / cm ³ or less, more preferably 0.95 g / cm ³ or less, more preferably 0.9 g / cm ³ or less is the [1] to dentifrice as claimed in any one of [4] .
[6] The dentifrice according to any one of the above [1] to [5], wherein the particle size distribution of the granules is preferably 75 to 500 μm, more preferably 100 to 500 μm.

[7] The dentifrice according to any one of the above [1] to [6], wherein preferably 70 to 100% of the granules are spherical, and more preferably 80 to 100% are spherical.
[8] The material of the granule is preferably selected from silica, aluminum hydroxide, magnesium phosphate, calcium carbonate, calcium pyrophosphate, zeolite, composite aluminosilicate, magnesium carbonate, dicalcium phosphate, tricalcium phosphate and insoluble sodium metaphosphate. 1 type or 2 types or more selected, more preferably 1 type or 2 types or more selected from silica, calcium carbonate, aluminum hydroxide, and zeolite, and more preferably silica of the above [1] to [7] The dentifrice of any one.

[9] The granule content is preferably 1% by mass or more, more preferably 1.2% by mass or more, still more preferably 1.5% by mass or more, and even more preferably 1.7% by mass. % Or more, Preferably it is 5 mass% or less, More preferably, it is 4.7 mass% or less, More preferably, it is 4.5 mass% or less, Any one of said [1]-[8] Dentifrice.
[10] The content of water is preferably more than 0% by mass, more preferably 10% by mass or more, preferably 60% by mass or less, and more preferably 50% by mass or less. [9] The dentifrice according to any one of [9].

[11] The dentifrice according to any one of the above [1] to [10], wherein the granules are silica granules produced by a wet method.
[12] The manufacturing process of the wet method includes a step of producing a silica sol by mixing an alkali metal silicate and an inorganic acid, a step of obtaining a silica hydrogel from the silica sol, and a water content of the obtained silica hydrogel of 50% or more The dentifrice of the above [11], which is a production method comprising a step of adjusting the water content to 80% or less.
[13] The dentifrice of [12], wherein the water content of the silica hydrogel is adjusted to 55% or more and 75% or less in the step of adjusting the water content.

  Hereinafter, the present invention will be specifically described based on examples. In addition, unless otherwise indicated in a table | surface, content of each component shows the mass%.

[Production Example 1: Production of granules A to D]
Granules A to D corresponding to the granules used in the present invention were prepared by a wet method (gel method). Specifically, first, silica sol was produced by mixing sodium silicate and sulfuric acid, and this was sprayed into the air to be gelled and spheroidized. Subsequently, the obtained spherical silica hydrogel was washed with water to remove impurities, subjected to hydrothermal treatment, and then filtered, dried, and classified (150 μm to 500 μm). The hydrothermal treatment conditions and drying conditions of the granules A to D are shown below.

Granule A: Spherical silica hydrogel was hydrothermally treated in an aqueous solution at pH 8.5 at 90 ° C. for 8 hours and then dried. The condition of the drying process was air current drying at a temperature of 110 ° C. for 90 seconds. The moisture content of the granule A after the drying step was 10% or less.
Granule B: Spherical silica hydrogel was hydrothermally treated at 90 ° C. for 8 hours in an aqueous solution of pH 8.5, and the water content was adjusted. In the water content adjusting step, the processing temperature and processing time were adjusted so that the water content of the adjusted granule B was 65% ± 10%.
Granule C: Spherical silica hydrogel was hydrothermally treated in an aqueous solution of pH 8.5 at 90 ° C. for 8 hours, then transferred to an autoclave, and 0.4 MPa (140 ° C.), 3 hours of high-pressure steam treatment (hydrothermal treatment) After performing, water content was adjusted. In the water content adjusting step, the processing temperature and the processing time were adjusted so that the water content of the adjusted granule C was 65% ± 10%.
Granule D: Spherical silica hydrogel was hydrothermally treated in an aqueous solution of pH 8.5 at 90 ° C. for 8 hours, then transferred to an autoclave, 0.4 MPa (140 ° C.), high pressure steam treatment (hydrothermal treatment) for 3 hours After performing, water content was adjusted. In the water content adjusting step, the processing temperature and the processing time were adjusted so that the water content of the adjusted granule D was 65% ± 10%.

  Table 1 shows the disintegration strength, the sphericity, the deformation rate, the average particle size, the packing density of the granules, and the number of granules per unit mass for the obtained granules AD.

<Method of measuring decay strength>
Using a compression tester (Shimadzu Corporation, MCTM-500), granules having a particle size (185 to 215 μm) were compressed at a load rate of 1.51 gf / sec. Strength.

《Spherical ratio》
When 50 granules are sampled at random and viewed with a microscope (KEYENCE, digital high-definition microscope VH-7000) at a magnification of 200 times, the ratio (%) of the number of spherical granules is obtained. did.

<Deformation rate>
When a granule (particle diameter of 185 to 215 μm) before blending was used in a dentifrice, and compression was applied to a single granule with a compression tester (Shimadzu Corporation, MCTM-500) at a load rate of 1.51 g / sec, The displacement of the particle size in the compression direction when the granule collapsed was divided by the particle size before compression (deformation rate (%) determined by (Equation 1) above). The range of deformation rate (MAX, MIN) and average value are described for 10 randomly extracted granules.

《Average particle size》
The average particle size of the granule is calculated by a sieving method (Tsutsui Rikagaku Co., Program-controlled Sonic Sieve SW-20AT) using JIS standard sieve openings, 75, 106, 150, 212, 250, 300, 500 μm. The 50% value of the integrated weight distribution. The granules in Table 1 were adjusted to an average particle size of 200 μm.

《Packing density》
After 60 g of granules were put into a graduated cylinder and tapped for 10 seconds, the scale of the graduated cylinder was read after 10 seconds, and the packing density was calculated by measuring the volume.

[Examples 1 to 6, Comparative Example 1]
Using the granules A to D obtained in Production Example 1, a dentifrice was prepared according to the formulation in Table 2.
About the obtained dentifrice, the dental plaque or dirt removal effect was evaluated by calculating | requiring model plaque removal rate (%) using the following evaluation models. A conceptual diagram of the operation is shown in FIG. 1, and the obtained model plaque removal rates (Examples 1 and 4 and Comparative Example 1) are shown in FIG.

<< Evaluation model >>
(Method)
(1) Five glass tubes with a diameter of 4 mm were arranged and fixed with an adhesive (long-time solidification type) to create an interdental model.
(2) Apply red lipstick (Aube Rouge de Recious RD305 (Kao)) as model plaque or dirt in the groove of the glass tube.
(3) Brush the excess coated lipstick with dishwashing detergent (without abrasive) (toothbrush “Bristles are regular” size, normal (Kao)) until no red color appears.
(4) Apply 2 g of various dentifrices on the lipstick.
(5) Under a load of 100 g, brush until the lipstick does not fall (the toothbrush is the same as (3)).
(6) Remove the dentifrice and lipstick with water.
(7) The interdental model is immersed in 100 mL of ethanol and subjected to ultrasonic cleaning for 10 minutes (residual lipstick elution from the back of the model interdental part).
(8) The absorbance of the ethanol solution obtained in (7) is measured (Abs) at 540 nm.
In addition, the control (initial value) used what performed the process of (7) and (8) after the process of said (3). The plaque or dirt removal rate of Evaluation Model 1 was calculated from the rate of decrease in absorbance (A) after evaluation with each dentifrice ((A0−A) / A0) × 100) relative to the absorbance (A0) of the control.
Subsequently, the model plaque removal rate (%) of Examples 1 to 6 when the plaque or dirt removal rate (model plaque removal rate) by the evaluation model of Comparative Example 1 was set to 100% was obtained. Table 2 shows the model plaque removal rate (%) together with the number of granules in 1 g of the dentifrice.

  As shown in Table 2, the plaque removal rate of the granules B to D of the present invention is higher than that of the granule A even in brushing at a brushing pressure of 100 g which is generally gentle to the gums. In addition, the granules B to D of the present invention have a high moisture content of 65%, and Comparative Example 1 and Examples 4 to 6 have almost the same number of granules in the dentifrice. Thus, when the number of granules in the dentifrice is approximately the same, granules BD (Examples 4-6) have a very high plaque removal rate compared to Comparative Example 1 (Granule A). .

[Examples 7 to 10, Comparative Example 2]
Using the granules A to C obtained in Production Example 1, a dentifrice was prepared according to the formulation in Table 3.
The resulting dentifrice was evaluated for the following feel. Table 3 shows the evaluation results together with the number of granules in 1 g of the dentifrice.
《Evaluation of feel》
Four people evaluated the feeling at the start of toothpaste and during brushing according to the following evaluation criteria. Toothbrushing was performed by brushing for 1 minute using a toothbrush (Clear Clean EX (normal), manufactured by Kao). The feeling at the start of dentifrice is evaluated as the feel of a dentifrice that is not diluted with saliva. The feel during brushing was evaluated. Of the four evaluation results obtained, the evaluation with a large number of people was adopted, and when the evaluation results were divided by two people, the average value was adopted.
3: Feeling smooth 2: Feeling slightly polished 1: Feeling polished

From the results of Table 3, compared to Comparative Example 2 using Granule A, Examples 7 to 10 using Granule B and Granule C are less likely to feel the unique polished feel of the granule and have a smooth feel. It is recognized that there is.
That is, since the granules used in the present invention have a high deformation rate, the obtained dentifrice of the present invention exhibits excellent dirt removal performance even by brushing under a low load gentle to the gums, as shown in Table 2. At the same time, as shown in Table 3, the feeling of being polished with granules at the time of toothbrushing is also reduced, and it is possible to achieve both dirt removal performance and a gum-friendly feel.

Claims (6)

The average particle size is 100 μm or more and 300 μm or less, the disintegration strength is 5 gf / piece or more and 10 gf / piece or less, the moisture content is 50% or more and 80% or less, and the load rate is 1.51 g / sec per granule. (Formula 1) at the time of collapse by applying compression:
Deformation rate (%) = (Displacement in compression direction at the time of collapse / particle diameter before compression) × 100 (Equation 1)
The dentifrice containing the granule whose deformation rate of the particle | grains of compression direction represented by these is 35% or more and 70% or less. Granules, dentifrice of claim 1 wherein the silica granules. The dentifrice according to claim 1 or 2 , wherein the packing density of the granules is 0.6 g / cm ³ or more and 1.0 g / cm ³ or less. The content of granules, dentifrice according to any one of claims 1 to 3, at most 1 mass% to 5 mass%. The dentifrice according to any one of claims 1 to 4, wherein 70 to 100% of the granules are spherical. A method for producing granules contained in the dentifrice according to any one of claims 1 to 5, wherein a step of producing a silica sol by mixing an alkali metal silicate and an inorganic acid, and a silica hydrogel from the silica sol obtaining a, the water content of the resulting silica hydrogel and a step of water adjusted to 80% or less than 50%, production how granules.