JP2014001187A - Method for producing dentifrice granule - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide dentifrice granules with excellent feelings in use, a dentifrice containing thereof, and a method for producing the dentifrice granules.SOLUTION: There are provided [1] dentifrice granules containing a water-insoluble powder material, zinc compound, and silicate, the silicate being at least one or two kinds selected from sodium silicate and potassium silicate, in the granules the content of zinc being 0.5 to 7 mass%, the content of silicate being 3 to 60 mass%, and the average wet collapse strength of the granules being 31 to 90%, [2] a dentifrice containing the dentifrice granules, and [3] a method of producing dentifrice granules comprising the steps of: (1) adding an aqueous solution of silicate to a mixture containing a water-insoluble powder material and zinc compound and giving a granulation treatment thereto; and (2) drying the granules obtained thereby.

Description

  The present invention relates to a dentifrice granule, a dentifrice containing the granule, and a method for producing a dentifrice granule.

  In recent years, dentifrices containing granules that can effectively remove dental plaque causing causative teeth and periodontal disease and are palpable are known. These granules are substantially spherical agglomerated particles and contain functional materials such as drugs, enzymes, and abrasives so as not to damage the enamel and gums on the tooth surface. And there is something that aimed at the visual effect.

For example, Patent Document 1 discloses a dentifrice containing granules having a certain size and strength obtained by binding a water-insoluble powder material with a water-insoluble inorganic binder and spray drying.
Patent Document 2 discloses a dentifrice composition containing a granular zeolite having an average particle size of 150 to 800 μm and an average disintegration strength of 15 to 100 g / piece, modified mint oil, etc. Disclosed is a product containing silicic anhydride and titanium oxide and prepared in a granular form by sintering.
Patent Document 3 discloses a toothpaste comprising granules obtained by drying aggregates of two kinds of water-insoluble fine particle materials which are substantially free of organic and / or inorganic binders and which are chemically and / or physically different from each other. Oral compositions are disclosed.
On the other hand, zinc compounds are known to have plaque formation-inhibiting effects. However, if the amount is increased in order to increase the effect, the flavor of the dentifrice is impaired due to the astringency and metallic taste of zinc.

JP-A-1-299211 JP 2008-266251 A Japanese National Patent Publication No. 10-50685

Conventionally, various water-soluble binders and water-insoluble binders have been used as granule binders. However, granules prepared using a water-soluble binder have no problem when used in a dry state. However, the strength of a dentifrice containing a large amount of water decreases, and during the process of mixing the dentifrice, Since the granules collapsed or the granules softened, it was difficult to feel in the oral cavity, and the presence of the granules was not sufficient.
On the other hand, as in Patent Document 1, a granule prepared using a water-insoluble inorganic binder can increase the particle strength relatively easily, but the water-insoluble inorganic binder is expensive.
As in Patent Document 2, when granulated zeolite is produced by a sintering method, it is difficult to adjust the disintegration strength of the granules.
Patent Document 3 describes an example of producing granules by substantially free of binder and agglomerates aggregated with water by drying in an oven or rotary kiln. The load of the drying operation (processing temperature and / or processing time) was large, and it was not satisfactory in terms of freedom of formulation, cost, and productivity.
The present invention has a good wet disintegration strength, effectively removes plaque while maintaining the form and strength in the dentifrice, and further has the effect of suppressing plaque formation. It is an object of the present invention to provide a dentifrice granule excellent in feeling, a dentifrice containing the granule, and a method for producing a dentifrice granule.

The present inventors maintain the form and strength in dentifrice because the dentifrice granules containing water-insoluble powder material and sodium or potassium silicate and zinc compounds have good wet disintegration strength. However, the present inventors have found that it has excellent usability, effectively removes plaque, and further has an effect of suppressing plaque formation.
That is, the present invention relates to the following [1] to [3].
[1] Granules containing a water-insoluble powder material, a zinc compound, and a silicate, wherein the silicate is one or two selected from sodium silicate and potassium silicate, and zinc is contained in the granule Granules for dentifrices having an amount of 0.5 to 7% by mass, a silicate content of 3 to 60% by mass and an average wet disintegration strength of 31 to 90%.
[2] A dentifrice containing the dentifrice granules of [1].
[3] The method for producing a dentifrice granule according to [1], comprising the following steps (1) and (2).
Step (1): Step of adding an aqueous solution of silicate to a mixture containing a water-insoluble powder material and a zinc compound and granulating Step (2): Step of drying the granules obtained in Step (1)

  According to the present invention, it has a good wet disintegration strength, effectively removes plaque, and further has an effect of suppressing plaque formation, and has an excellent feeling of use for a dentifrice granule. A dentifrice and a method for producing dentifrice granules can be provided.

[Granule for dentifrice]
The granule for dentifrice of the present invention is a granule comprising a water-insoluble powder material, a zinc compound, and a silicate, wherein the zinc content is 0.5 to 7% by mass, The content is 3 to 60% by mass, the silicate is one or two selected from sodium silicate and potassium silicate, and the average wet disintegration strength is 31 to 90%.

The granule for dentifrice of the present invention has an excellent wet disintegration strength and can maintain the morphological strength even in water, and thus has an excellent feeling of use of the granule and an effect of removing plaque. The reason why the dentifrice granules of the present invention are excellent in wet disintegration strength is thought to be because the network structure of the silicate used as a binder is reinforced by a zinc compound.
Hereafter, each component used for the dentifrice granule of this invention, the manufacturing method of the granule for dentifrice, and the dentifrice containing this granule are demonstrated one by one.

[Water-insoluble powder material]
As the water-insoluble powder material used in the present invention, those usually used for tooth abrasives can be used, and specifically, inorganic materials are preferable. Here, “water-insoluble” means that the amount dissolved in 100 g of water (20 ° C.) is 1 g or less.
Specific examples of water-insoluble powder materials include light calcium carbonate, heavy calcium carbonate, zeolite, silica, dicalcium phosphate, tricalcium phosphate, insoluble sodium metaphosphate, aluminum hydroxide, magnesium phosphate, calcium pyrophosphate, magnesium carbonate, And one or more selected from titanium oxide and the like. These can be used alone or in combination of two or more.

The average particle size of the water-insoluble powder material is preferably from 0.1 to 100 μm, more preferably from 0.5 to 50 μm, and even more preferably 1 from the viewpoint of not feeling the dirt removal force of the teeth after granule disintegration and the feeling of foreign matter. It is -20 micrometers, Most preferably, it is 5-15 micrometers.
Among these, one or two or more selected from light calcium carbonate, heavy calcium carbonate, zeolite, and silica are preferable from the viewpoint of physical properties and cost when granulated.
The calcium carbonate may be light calcium carbonate or heavy calcium carbonate. Light calcium carbonate is preferable from the viewpoints of purity and homogeneity. Heavy calcium carbonate is preferable from the viewpoint of cost. Moreover, these both can also be mixed and used.
When silica is used as the water-insoluble powder, the average particle size is preferably 0.1 to 100 μm, more preferably 0.5 to 0.5 from the viewpoint of not feeling the dirt removal ability of the teeth after granule disintegration and the feeling of foreign matter. The thickness is 50 μm, more preferably 1 to 20 μm, particularly preferably 5 to 15 μm.

When a zeolite is used as the water-insoluble powder, a natural one contains impurities and lacks homogeneity. Therefore, a synthetic one, that is, a synthetic zeolite is preferable, and among these, an A-type zeolite is preferable.
The average particle size of the zeolite particles is usually about 0.1 to 20 μm, but it is sufficient to remove the colored pellicle that is strongly adsorbed on the tooth surface even if granulated low abrasive particles of 10 μm or less. Abrasive force is generated to whiten the teeth, and after granule disintegration, the abrasive force is reduced, and it is possible to give the feature that the tooth is not damaged even by a long-time brushing operation (low damage).
If the average particle size of zeolite is small, there is an advantage that the ion exchange ability is enhanced, and the plaque removal effect and the calculus prevention effect are further enhanced. In this case, the smaller the primary particle size, the higher the ion exchange capacity and the higher the plaque removal effect. However, in consideration of the polishing effect, the average particle size of the zeolite used is preferably 0.5 to 10 μm, and preferably 1 to 8 μm. More preferably, 3-7 micrometers is still more preferable.

The average particle size of the water-insoluble powder material is preferably 0.1 μm or more, more preferably 0.5 μm or more, and even more preferably 0.8 μm or more, from the viewpoint of removing dirt on the teeth after granule disintegration. From the viewpoint of reducing, the upper limit is preferably 20 μm or less, more preferably 10 μm or less, and still more preferably 5 μm or less. The average particle size of the water-insoluble powder material is preferably 0.1 to 20 μm, more preferably 0.5 to 10 μm, and still more preferably 0.8 to 5 μm.
The average particle diameter can be measured by the method described in the examples.

[Zinc compounds]
In the present invention, a zinc compound is used from the viewpoint of imparting a plaque formation inhibitory effect and from the viewpoint of enhancing the wet disintegration strength by strengthening the silicate network structure. There is no restriction | limiting in particular as a zinc compound, An inorganic or organic zinc compound can be used.
Inorganic zinc compounds include zinc oxide, zinc carbonate, zinc borate, zinc hydroxide, zinc phosphite, zinc phosphate, zinc diphosphate, zinc nitrate, zinc sulfate, zinc sulfide, zinc acetate, zinc fluoride And zinc halide. Among these, zinc oxide, zinc nitrate, zinc sulfate, zinc chloride and the like are preferable, and zinc oxide is more preferable from the viewpoint of improving wet disintegration strength and availability.
Examples of the organic zinc compound include zinc carbonate, zinc lactate, zinc gluconate, zinc citrate, zinc phosphate, zinc stearate, zinc myristate, zinc laurate, etc., zinc lactate, zinc citrate, zinc carbonate Is more preferable.
The solubility of the zinc compound in water is preferably 2 mg / 100 mL (15 ° C.) or less. Moreover, it is preferable to use the zinc compound which has a powder form or a particulate form from a viewpoint of the plaque formation inhibitory effect. From these viewpoints, an inorganic zinc compound is preferable, and zinc oxide is more preferable.

[Silicate]
In the present invention, silicate is used for imparting excellent wet disintegration strength to granules. This silicate also has a function of increasing the wet disintegration strength of the granules by appropriately drying the granules as necessary, as in step (2) in the method of the present invention. By adjusting the type and amount of silicate, the wet disintegration strength of the granules can be adjusted as appropriate.
The silicate is one or two selected from sodium silicate and potassium silicate, and sodium silicate is preferable.
Examples of sodium silicate include 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 the like. 1 type or 2 types or more chosen from these hydrates are mentioned.
Sodium silicate is generally 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 a molar ratio and can be expressed by the following formula (1).
Molar ratio = mass ratio (SiO ₂ mass% / Na ₂ O mass%) × (Molecular weight of Na ₂ O / Molecular weight of SiO ₂ ) (1)
As sodium silicate, water glass having various molar ratios can be used in addition to sodium silicate Nos. 1, 2, and 3 described in JIS K1408.
Although the physical properties of sodium silicate vary depending on the molar ratio, the molar ratio is preferably 2.0 to 4.0, more preferably from the viewpoint of compatibility with quasi-drug raw material specifications and the pH of the granules to be obtained. Is 2.4 to 3.5, more preferably 3.0 to 3.3.

[Other ingredients]
In the present invention, a water-insoluble inorganic binder, water, in addition to the water-insoluble powder material (abrasive) and silicate (binder) used in the present invention, if necessary, within a range not impairing the object of the present invention. Insoluble organic binders, organic fibers, medicinal ingredients, colorants and the like can be blended.
As the water-insoluble inorganic binder that can be used in the method of the present invention, a silicon-based compound, an aluminum-based compound, a calcium-based compound, a magnesium-based compound, and the like having a hydroxyl group can be used. Specific examples include colloidal silica, magnesium aluminate metasilicate, synthetic aluminum silicate, calcium silicate, bentonite, montmorillonite, kaolin, alumina sol, synthetic hydrotalcite, magnesium oxide, and magnesium hydroxide.
Examples of the fats and oils that can be used as the water-insoluble organic binder include higher fatty acids such as wax, paraffin, stearic acid, magnesium stearate, calcium stearate, and salts thereof.
Polymers and resins that can be used as water-insoluble organic binders include (i) polysaccharides such as xanthan gum, dextrin, gelatin, and derivatives thereof, (ii) rubber latex, (iii) acrylic acid, acrylic ester , Methacrylic acid, methacrylic acid ester, hydroxymethacrylic acid ester, styrene, vinyl acetate, vinyl pyrrolidone, maleic acid ester, methyl vinyl ether, α-olefin homopolymers, copolymers thereof and the like.
Examples of the organic fiber include cellulose, hemicellulose, lignin, chitin, and the like. Among these, cellulose is particularly preferable from the viewpoint of removing plaque from the granules.

  Medicinal ingredients include caries preventive agents, antimicrobial agents, enzymes, anti-inflammatory agents, etc., specifically sodium fluoride, potassium fluoride, tin fluoride, sodium monofluorophosphate, vitamin E, vitamins C, dextranase, mutanase, sodium chloride and other anti-inflammatory agents; aluminum lactate, azulene, glycyrrhetinic acid, β-glycyrrhetinic acid, allantochlorhydroxyaluminum chloride, lysozyme chloride, epsilon aminocaproic acid, copper chlorophyllin sodium, copper gluconate, acetic acid Antiperceptive agents such as dl-tocopherol and potassium nitrate; anticalculus agents such as sodium tripolyphosphate and ethanehydroxydiphosphonate; dihydrcholesterol, chlorhexidine, epidihydrcholesterol, isopropylmethylphenol, tri Rorokarubanirido, halocarban, hinokitiol, allantoin, tranexamic acid, propolis, benzethonium chloride, cetylpyridinium chloride, fungicides such as triclosan, polyethylene glycol, Tabakoyani removers such as polyvinylpyrrolidone and the like.

Examples of the colorant include titanium oxide and ultramarine blue, and an aesthetic effect can be added by adding these colorants.
The said other compounding component can be used individually or in combination of 2 or more types.

[Method for producing granules for dentifrice]
Although there is no restriction | limiting in particular in the manufacturing method of the granule for dentifrice of this invention, According to the method which has the following process (1) and (2), the granule for dentifrice which has the outstanding wet disintegration strength is manufactured efficiently. I can roll.
Step (1): Step of adding an aqueous solution of silicate to a mixture containing a water-insoluble powder material and a zinc compound and granulating Step (2): Step of drying the granules obtained in Step (1)

<Step (1)>
Step (1) is a step of granulating by adding a water-insoluble powder material, a zinc compound, and other materials as necessary, using an aqueous solution of silicate as a binder, and granulating it.
Examples of the granulation method include commonly used granulation methods such as rolling granulation, stirring granulation, fluidized bed granulation and the like. Among these, using a container rotating granulator without a stirring blade has good disintegration (that is, good wet disintegration strength) while maintaining the form and strength in the dentifrice. It is preferable because it effectively removes plaque and at the same time can confine the zinc compound inside the granule and suppress the bitterness and metallic taste.
The solid content in the aqueous silicate solution used in the step (1) is preferably 10% by mass or more, more preferably 20% by mass or more, and further preferably 30% by mass from the viewpoint of granulating a water-insoluble powder material as a binder. From the viewpoint of handling properties and spraying as droplets and suppressing coarse particles, the content is preferably 60% by mass or less, more preferably 50% by mass or less, and still more preferably 40% by mass or less.
In addition, solid content in silicate aqueous solution can be calculated | required by the method of an Example description.

In the method using the container rotating granulator, the bitterness of the zinc compound can be suppressed as compared with the ordinary spray drying method. This is considered to be because the zinc compound is easily confined inside the granule when the container rotating granulator is used while it is easily moved to the vicinity.
Furthermore, in granulation using a container rotating granulator, the powder can be made to flow uniformly, and further, because of the mixing mechanism that involves lifting of particles by rotation and sliding / falling by its own weight, The shearing force applied to is suppressed. That is, since the granulation method using a container rotating granulator is a non-consolidated granulation method, the aqueous solution of silicate present in the granules is easily dried, and the dehydrated product obtained thereby is strong in the granules. It is considered that the above effects can be obtained.
Therefore, the step (1) is preferably a step of adding a silicate aqueous solution to a mixture containing a water-insoluble powder material and a zinc compound and granulating it using a container rotating granulator. More preferably, it is a step of granulating by supplying as droplets using a nozzle.
In addition, prior to performing the step (1), it is preferable that only the water-insoluble powder is previously charged in the granulator and mixed. By carrying out this step, the water-insoluble powder is more uniformly dispersed and mixed, and it is possible to obtain dentifrice granules having stable performance regardless of the batch. The mixing is preferably performed for 0.5 to 10 minutes, more preferably 1 to 5 minutes.

(Container rotating granulator)
As the container rotating granulator, a drum granulator and a bread granulator are preferable. The drum granulator is not particularly limited as long as the drum-shaped cylinder rotates and performs processing. Besides a drum granulator that is horizontally or slightly inclined, a conical drum granulator, a multi-stage conical drum granulator, or the like can be used. These apparatuses may be either batch type or continuous type.
If the wall friction coefficient between the powder containing the water-insoluble powder material and the inner wall of the container rotary granulator is small, it is difficult to apply sufficient ascending force to the powder. It is preferable to provide a plurality of baffles for assisting. By providing the baffle plate, it is possible to impart an upward movement to the powder, and the powder mixing property and the solid-liquid mixing property are improved.

The operating conditions of the container rotating granulator are not particularly limited as long as the water-insoluble powder material in the granulator can flow and be stirred as uniformly as possible. From the viewpoint of obtaining granules having excellent wet disintegration strength and the like, the fluid number defined by the following formula (2) is preferably 0.005 or more, more preferably 0.01 or more, and non-consolidated From the viewpoint of obtaining granules, the upper limit is preferably 1.0 or less, and more preferably 0.6 or less.
Fluid number: Fr = V ² / (R × g) (2)
V: Circumferential speed [m / s]
R: Radius from the center of rotation to the circumference of the rotating object [m]
g: Gravity acceleration [m / s ² ]
In a drum granulator or a bread granulator in which granulation proceeds by rotation of the main body, V and R use the values of the main body, and horizontal or vertical type with a main wing and a crushing wing. In the granulator, V and R use the value of the main shaft, and in the bread granulator equipped with the crushing blade, V and R use the value of the crushing blade.

(Multi-fluid nozzle)
In the present invention, it is preferable to supply a silicate aqueous solution using a multi-fluid nozzle from the viewpoint of suppressing the formation of coarse particles. By using a multi-fluid nozzle, the droplets can be made fine and dispersed.
A multi-fluid nozzle is a nozzle that mixes and atomizes a liquid and atomizing gas (air, nitrogen, etc.) through an independent channel to the vicinity of the nozzle tip. Examples include fluid nozzles. Moreover, the mixing part of the silicate aqueous solution and the atomizing gas may be either an internal mixing type that mixes within the nozzle tip or an external mixing type that mixes outside the nozzle tip.

  As such a multi-fluid nozzle, an internally mixed two-fluid nozzle made by Spraying Systems Japan Co., Ltd., Kyoritsu Alloy Manufacturing Co., Ltd., Ikeuchi Co., Ltd., etc., manufactured by Spraying Systems Japan Co., Ltd., Kyoritsu Co., Ltd. Examples thereof include an external mixed type two-fluid nozzle manufactured by Alloy Seisakusho, manufactured by Atmax Co., Ltd., and an external mixed type four-fluid nozzle manufactured by Fujisaki Electric Co., Ltd.

The droplet diameter of the silicate aqueous solution can be adjusted to a desired range by adjusting the balance between the flow rate of the silicate aqueous solution and the flow rate of the atomizing gas. That is, in order to reduce the droplet diameter, the flow rate of the atomizing gas may be increased with respect to the silicate aqueous solution having a constant flow rate. What is necessary is just to reduce a flow volume.
For example, when a two-fluid nozzle is used, it is easy to adjust the flow rate of the atomizing gas by adjusting the atomizing pressure of the atomizing gas. The atomizing gas spray pressure is preferably 0.1 MPa or more from the viewpoint of liquid dispersion, and preferably 1.0 MPa or less from the viewpoint of equipment load. Moreover, there is no restriction | limiting in particular as spray pressure of sodium silicate, However, 1.0 MPa or less is preferable from a viewpoint of equipment load, for example.

As a result of examining the effect of the difference in the droplet size of the silicate aqueous solution on the yield and coarse particle ratio of the obtained granules, from the viewpoint of obtaining a well-balanced granule with a suitable particle size for wet disintegration strength and a dentifrice granule, The average particle diameter of the droplet diameter of the silicate aqueous solution is preferably 210 μm or less, more preferably 150 μm or less, and even more preferably 100 μm or less. From the viewpoint of productivity, it is preferably 1 μm or more, more preferably 5 μm or more, and further Preferably it is 10 micrometers or more.
The smaller the droplet diameter, the lower the flow rate of the aqueous silicate solution and the lower the productivity.For example, by using multiple multi-fluid nozzles and reducing the flow rate per nozzle, maintaining finer droplets. In addition, the addition rate can be increased. One or more multi-fluid nozzles may be used, but 2 to 20 nozzles may be used.
In addition, the average particle diameter of the droplet diameter of the silicate aqueous solution is calculated on a volume basis, and is, for example, a value measured using a laser diffraction particle size distribution measuring apparatus (Malburn, Spraytec). is there. Specifically, it can be measured by the method described in the examples.

The temperature of the aqueous solution when supplying the aqueous solution of the water-soluble silicate using a multi-fluid nozzle is preferably 5 to 50 ° C, more preferably 10 to 30 ° C, from the viewpoint of spray stability.
In the step (1) of the present invention, from the viewpoint of granulating the water-insoluble powder material, the mass ratio of the solid content in the silicate aqueous solution to the water-insoluble powder material (solid content in the silicate aqueous solution / water-insoluble powder material) is Preferably, it is 0.03 or more, more preferably 0.04 or more, and still more preferably 0.05 or more. From the viewpoint of reducing the coarse particles and increasing the yield, the mass ratio is preferably 1.0 or less. More preferably, it is 0.5 or less, and further preferably 0.2 or less. The mass ratio is preferably 0.03 to 1.0, more preferably 0.04 to 0.5, and still more preferably 0.05 to 0.2.

In the step (1) of the present invention, the mass ratio of zinc to the silicate aqueous solution (the solid content in the zinc / silicate aqueous solution) is preferably 0 from the viewpoint of increasing the wet disintegration strength and enhancing the plaque formation inhibitory effect. 0.02 or more, more preferably 0.05 or more, still more preferably 0.1 or more, and preferably 2 or less, more preferably 1.5 or less, even more preferably from the viewpoint of suppressing astringency and metallic taste due to zinc. Is 1 or less, more preferably 0.8 or less.
The addition rate of the silicate aqueous solution is preferably 35 parts by mass with respect to 100 parts by mass of the water-insoluble powder material from the viewpoint of suppressing the formation of coarse particles and imparting appropriate disintegration strength and excellent wet disintegration strength. / Min or less, more preferably 20 parts by mass or less, even more preferably 10 parts by mass or less, and the lower limit thereof is preferably 1 part by mass or more, more preferably 1.5 parts by mass or more, More preferably, it is 2 parts by mass / min or more. The above range is suitable when using sodium silicate No. 1, 2 or 3 described in JIS K1408.
The addition rate of silicate (solid content) is preferably 19 parts by mass or less, more preferably 11 parts by mass or less, with respect to 100 parts by mass of the water-insoluble powder material, from the same viewpoint as described above. The lower limit is preferably 0.6 parts by mass / min or more, more preferably 0.8 parts by mass / min or more, and further preferably 1.1 parts by mass / min. More than a minute.

<Step (2)>
Step (2) is a step of drying the granules obtained in step (1). Surprisingly, it was found that by performing a drying operation while using an aqueous solution of silicate, the wet disintegration strength of the granules was also improved, and the stability in the dentifrice formulation could be improved. Although the detailed reason is not clear, it is thought that the dehydration condensation of silicate progresses with drying, the network structure of silicate develops, and wet disintegration strength improves.

Examples of the drying method include shelf drying, fluidized bed drying, reduced pressure drying, and microwave drying. Among these, from the viewpoint of equipment, shelf drying and fluidized bed drying are preferable.
From the viewpoint of suppressing the disintegration of the granules during drying, a drying method that does not give as much shearing force as possible is preferable. For example, in the batch type, examples include a method of drying with an electric shelf dryer or a hot air dryer, a method of drying in a batch type fluidized bed, and the continuous type includes a fluidized bed, a rotary dryer, a steam tube dryer, and the like. It is done.
The drying temperature can be appropriately determined in consideration of the drying speed, but is preferably 60 ° C. or higher, more preferably 70 ° C. or higher, and still more preferably 80 ° C. or higher. From the viewpoint of heat load, the upper limit is preferably 200 ° C. or lower, more preferably 150 ° C. or lower, still more preferably 110 ° C. or lower, and most preferably 90 ° C. or lower.
From the viewpoint of controlling the temperature of the granule, the temperature of the heat medium used for drying is preferably a temperature not higher than 20 ° C. or higher than the maximum temperature of the granule, and more preferably not higher than 15 ° C. Further, from the viewpoint of the drying rate, a temperature higher by 5 ° C. or higher than the maximum temperature of the granule is preferable, and a temperature higher by 10 ° C. or higher is more preferable.
The drying time varies depending on the effective amount and amount of the silicate aqueous solution used in the production, the type of drying machine, and the drying temperature, but is appropriately adjusted so that the wet disintegration strength is within the preferable range of the present invention. The drying time is preferably about 10 minutes to 24 hours, more preferably about 20 minutes to 20 hours, and still more preferably about 30 minutes to 12 hours. In the case of electric shelf drying, it is preferably about 10 minutes to 24 hours, more preferably about 30 minutes to 12 hours, and in the case of fluidized bed drying, preferably about 10 minutes to 5 hours, more preferably 20 minutes. About 2 hours.

  The water content in the resulting granule is preferably 4% by mass or less, more preferably 2% by mass or less, still more preferably 1% by mass or less from the viewpoint of increasing wet disintegration strength, and from the viewpoint of productivity, It is 0.1 mass% or more, More preferably, it is 0.2 mass% or more. The amount of water in the granules can be determined by the method described in the examples. Although the wet disintegration strength depends on the type of the water-insoluble powder material, the wet disintegration strength is higher for the same type when the water content is smaller.

[Granule for dentifrice]
The dentifrice granule of the present invention can be suitably obtained by the above-described method, and the contents of the water-insoluble powder material, the silicate, and the zinc compound are as follows.
In the dentifrice granule of the present invention, the content of the water-insoluble powder material is preferably 40% by mass or more, more preferably 50% by mass or more, still more preferably 60% by mass or more, and still more from the viewpoint of enhancing the cleaning power. The upper limit is preferably 70% by mass or more, and from the viewpoint of the degree of freedom of granule composition, the upper limit is preferably 96% by mass or less, more preferably 95% by mass or less, and still more preferably 94% by mass or less. In the dentifrice granule, the content of the water-insoluble powder material is preferably 40 to 96% by mass, more preferably 50 to 95% by mass, and still more preferably 60 to 94% by mass. In this invention, the calculated value calculated | required from the compounding quantity at the time of granule manufacture can be used for content and mass ratio of each component in the granule for dentifrice. Moreover, the amount of silicate is the amount of solid content calculated | required by the method of an Example description.

  In the dentifrice granule of the present invention, the content of silicate is 3% by mass or more, preferably 4% by mass or more, more preferably 5% by mass or more, from the viewpoint of increasing the disintegration strength and the like. From the viewpoint of suppressing adhesion in the machine, reducing the coarse particle ratio, and improving the yield, the upper limit is 60% by mass or less, preferably 50% by mass or less, more preferably 40% by mass or less, and still more preferably. Is 30% by mass or less, more preferably 20% by mass or less. In dentifrice granules, the content of silicate is 3 to 60% by mass, preferably 4 to 50% by mass, more preferably 5 to 40% by mass, still more preferably 5 to 30% by mass, and still more preferably. Is 5 to 20% by mass.

  From the viewpoint of granulating the water-insoluble powder material in the dentifrice granules of the present invention, the mass ratio of silicate to the water-insoluble powder material (silicate / water-insoluble powder material) is preferably 0.03 or more, more preferably. Is 0.04 or more, more preferably 0.05 or more, and from the viewpoint of increasing the yield by reducing coarse particles, the mass ratio is preferably 1.0 or less, more preferably 0.5 or less, Preferably it is 0.2 or less. The mass ratio is preferably 0.03 to 1.0, more preferably 0.04 to 0.5, and still more preferably 0.05 to 0.2.

Usually, in order to increase the disintegration strength of granules and the stability in dentifrice, it is necessary to perform heat treatment such as drying. Surprisingly, the wet disintegration strength of granules can be improved by adding a zinc compound. be able to.
The content of the zinc compound in the dentifrice granule is preferably 0.5% by mass or more, more preferably 1% by mass or more, and still more preferably 1.5% by mass or more, from the viewpoint of the effect of suppressing plaque formation. . Moreover, from a viewpoint of suppressing the astringency and metal taste by zinc, Preferably it is 10 mass% or less, More preferably, it is 8 mass% or less, More preferably, it is 6 mass% or less.
The content of zinc in the dentifrice granule is 0.5% by mass or more, preferably 1% by mass or more, and more preferably 1.5% by mass or more from the viewpoint of the effect of suppressing plaque formation. Further, from the viewpoint of astringency and metallic taste due to zinc, the zinc content is 7% by mass or less, preferably 6% by mass or less, more preferably 5% by mass or less. Moreover, content of zinc in the granule for dentifrice is 0.5-7 mass%, Preferably it is 1-6 mass%, More preferably, it is 1.5-5 mass%.
The zinc content in the dentifrice granule when using a zinc compound can be calculated by the following formula (3).
Content of zinc in dentifrice granules = [content of zinc compound × 65.38 (atomic weight of zinc)] / molecular weight of zinc compound (3)

  In the dentifrice granules, the mass ratio of zinc content to silicate content (zinc / silicate) is preferably 0.02 or more, more preferably 0.00, from the viewpoint of enhancing the effect of inhibiting plaque formation. 05 or more, more preferably 0.1 or more, and preferably 2 or less, more preferably 1.5 or less, still more preferably 1 or less, and still more preferably 0, from the viewpoint of suppressing astringency and metallic taste due to zinc. .8 or less. The mass ratio (zinc / silicate) is preferably 0.02 to 2, more preferably 0.05 to 1.5, still more preferably 0.1 to 1, and still more preferably 0.1 to 0.8. is there.

  The content of the optional binder, medicinal component, and colorant is 3 parts by mass or less based on the total amount of 100 parts by mass of the solid content of the water-insoluble powder material, zinc compound, and silicate from the viewpoint of disintegration feeling. Is preferably 2 parts by mass or less, and may not be blended. That is, in the granule of the present invention, the total amount of the water-insoluble powder material, the zinc compound, and the silicate is preferably 97 to 100% by mass, more preferably 98 to 100% by mass, still more preferably 99 to 100% by mass, Substantially 100% by weight is even more preferred.

<Characteristics of dentifrice granules>
The average particle size of the dentifrice granules of the present invention is preferably 50 μm or more, more preferably 75 μm or more, and even more preferably 100 μm or more from the viewpoint of sufficient cleaning properties, and suppresses the feeling of foreign matter in the oral cavity. From the viewpoint, it is preferably 500 μm or less, more preferably 350 μm or less, and still more preferably 300 μm or less. The average particle size of the dentifrice granules is preferably 50 to 500 μm, more preferably 75 to 350 μm, and still more preferably 100 to 300 μm.
In addition, an average particle diameter can be measured by the method as described in an Example.

The average wet disintegration strength of the dentifrice granule is 31% or more from the viewpoint of being able to feel the granule in the mouth when used in a dentifrice and recognizing the plaque removal effect, preferably 35% or more, more preferably 40% or more, and 90% or less, preferably 80% or less, more preferably 75% or less, from the viewpoint of hardly feeling a foreign object. The average wet disintegration strength is 31-90%, preferably 35-80%, more preferably 40-75%.
In addition, average wet disintegration strength is measured by the method as described in an Example.

The mass frequency of the granules having a particle size of 355 μm or more of the dentifrice granules of the present invention is preferably 20% by mass or less, more preferably 18% by mass or less, from the viewpoint of suppressing the feeling of foreign matter in the oral cavity, and from the viewpoint of the cleaning effect of the granule formulation Therefore, 5 mass% or more is preferable, 8 mass% or more is more preferable, and 10 mass% or more is still more preferable. The mass frequency of granules of 355 μm or more is preferably 5 to 20% by mass, more preferably 8 to 18% by mass, and still more preferably 10 to 18% by mass.
In addition, the mass frequency of granules of 90 μm or less of the dentifrice granules of the present invention is preferably 25% by mass or less, more preferably 20% by mass or less, still more preferably 18% by mass or less, from the viewpoint of recognition of the granules. From the viewpoint of productivity, it is preferably 3% by mass or more, more preferably 5% by mass or more, and further preferably 8% by mass or more. The mass frequency of the granules of 90 μm or less is preferably 3 to 25% by mass, more preferably 5 to 20% by mass, and still more preferably 8 to 18% by mass.

Further, the difference between the pH of the 10-fold diluted solution of the dentifrice after the granule collapse of the granule for dentifrice of the present invention and the pH of the 10-fold diluted solution of the dentifrice before the granule collapse (pH after disintegration−pH before disintegration) is Preferably, it is 0.1-1.0, More preferably, it is 0.2-0.8, More preferably, it is 0.2-0.5. Due to this property, not only is it excellent in the usual dirt removing effect, but also the pH locally rises when the dentifrice granule of the present invention is disintegrated. It is thought that the plaque removal effect is remarkably excellent because it destroys the structure. In addition, due to this property, the dentifrice containing the dentifrice granules of the present invention can exhibit an alkaline plaque removing effect without increasing the pH of the dentifrice itself, so that the dentifrice contains alkali in the dentifrice. It is also preferable in terms of preventing deterioration of weak components such as fragrances.
In addition, the pH of the 10-fold diluted solution of the dentifrice after granule disintegration and the pH of the 10-fold diluted solution of the dentifrice before granule disintegration can be measured by the methods described in Examples.

As described above, the granule for a dentifrice of the present invention has both a water absorption rate and a pH increase property at the time of disintegration. Therefore, it takes a certain time to disintegrate in the presence of water during dentifrice, and the granule disintegration site The pH can be kept high locally. Based on such properties, the granule for dentifrice of the present invention is considered not only to be excellent in normal soil removing effect but also to be excellent in removing plaque containing protein.
Granules having the above average particle size, disintegration strength, and the like can be produced by appropriately changing the type, blending amount, and production conditions of the water-insoluble powder material, zinc compound, and water-soluble silicate.

[Dentifrice]
The granule for a dentifrice of the present invention and the granule obtained by the method of the present invention are preferably blended in a dentifrice preferably 1% by mass or more, more preferably 3% by mass or more from the viewpoints of plaque removal and tactile properties. In view of preventing damage to teeth, it is preferably 50% by mass or less, more preferably 30% by mass or less. When using a dentifrice containing granules of the above composition, the granules can be palpated in the oral cavity, giving a squirrel-like feel (crispness), but gradually disintegrating, and a cleaning effect can be recognized. It has characteristics and has an excellent plaque removal effect.

The dentifrice can be prepared by a conventional method. At this time, other ingredients usually used in dentifrices, such as binders, wetting agents, sweeteners, surfactants, preservatives, fragrances, medicinal ingredients, colorants, and other commonly used calcium carbonate An abrasive for dentifrices, excipients and the like can be blended.
Examples of the binder include sodium carboxymethyl cellulose, sodium polyacrylate, hydroxyethyl cellulose, thickening silica, montmorillonite, carrageenan, sodium alginate, guar gum, pectin and the like.
Examples of the wetting agent include sorbit, propylene glycol, 1,3 butylene glycol, ethylene glycol, polyethylene glycol, polypropylene glycol, xylit, maltite, lactit, erythritol, and the like. Sweetening agents include saccharin sodium, stevioside, and timertin (thaumatin). And aspartylphenylalanine methyl ester.

Surfactants include alkyl sulfates such as sodium lauryl sulfate, acyl amino acid salts such as sodium acyl glutamate and sodium acyl sarcosinate, alkyl phosphate salts such as sodium lauryl phosphate, sucrose fatty acid esters, sorbitan fatty acid esters, And polyoxyethylene fatty acid esters.
Examples of the preservative include paraben, methyl p-oxybenzoate, ethyl p-oxybenzoate, propyl p-oxybenzoate, butyl p-oxybenzoate, sodium benzoate and the like.
Perfumes include menthol and natural products including menthol; basil, camphor, caraway, cardamom, coriander, geranium, ginger, laurel, lavender, mace, nutmeg, pepper, rose, rosemary, thyme, ylang ylang, jasmine, vanilla , Hysop, Lavandin, Oris, Carrot Seed, Davana, Jeremi, Osmantas essential oil and extract; Borneol and its derivatives; Heliotropin; α-, β-, γ-, δ-ionone and their derivatives; Thymol, Vanillin Examples include ethyl vanillin, maltol and ethyl maltol.
Examples of the medicinal component and the colorant include those described above.
The said component can be used individually or in combination of 2 or more types.

In relation to the above-described embodiment, the present invention further discloses the following method for producing dentifrice granules and dentifrice granules obtained by the method.
<1> A granule containing a water-insoluble powder material, a zinc compound, and a silicate, wherein the silicate is one or two selected from sodium silicate and potassium silicate, and zinc is contained in the granule The amount is 0.5-7% by mass, preferably 1-6% by mass, more preferably 1.5-5% by mass, and the silicate content is 3-60% by mass, preferably 4-50% by mass. , More preferably 5 to 40% by mass, still more preferably 5 to 30% by mass, and still more preferably 5 to 20% by mass, and an average wet disintegration strength of 31 to 90%, preferably 35 to 80%, more preferably Is a dentifrice granule that is 40-75%.

<2> The mass ratio of zinc to silicate (zinc / silicate) is 0.02 to 2, preferably 0.05 to 1.5, more preferably 0.1 to 1, still more preferably 0.1 to 0. The method for producing a dentifrice granule according to <1>, which is .8.
<3> The water-insoluble powder material is one or more selected from light calcium carbonate, heavy calcium carbonate, zeolite, and silica, preferably one or two selected from light calcium carbonate and heavy calcium carbonate The method for producing a dentifrice granule according to <1> or <2>, more preferably heavy calcium carbonate.
<4> Mass ratio of silicate to water-insoluble powder material (silicate / water-insoluble powder material) is 0.03 to 1.0, preferably 0.04 to 0.5, more preferably 0.05 to 0. The method for producing a dentifrice granule according to any one of <1> to <3>, which is .2.
<5> The method for producing a dentifrice granule according to any one of <1> to <4>, wherein zinc is zinc oxide.

<6> The content of the water-insoluble powder material is 40 to 96% by mass, preferably 50 to 95% by mass, more preferably 60 to 94% by mass, according to any one of <1> to <5>. A method for producing dentifrice granules.
<7> The mass frequency of granules of 355 μm or more is 5 to 20% by mass, preferably 8 to 18% by mass, more preferably 10 to 18% by mass, and the mass frequency of granules of 90 μm or less is 3 to 25% by mass, The method for producing a dentifrice granule according to any one of <1> to <6>, preferably 5 to 20 mass%, more preferably 8 to 18 mass%.

<8> A dentifrice containing the dentifrice granules according to any one of <1> to <7>.
<9> The method for producing a dentifrice granule according to any one of <1> to <7>, which comprises the following steps (1) and (2).
Step (1): Step of adding an aqueous solution of silicate to a mixture containing a water-insoluble powder material and a zinc compound and granulating Step (2): Step of drying the granules obtained in Step (1) <10 > Granules for dentifrice according to the above <9>, wherein the step (1) is a step of mixing and granulating a water-insoluble powder material, an aqueous solution of silicate and a zinc compound using a container rotating granulator. Manufacturing method.

  In the following Examples and Comparative Examples, “%” is “% by mass” unless otherwise specified. Each physical property value was measured by the following method.

(1) Measurement of solid content of silicate Using a dropper, 2.5 g of a sample is placed on an aluminum 11.5 cm diameter container so that one drop becomes a droplet having a diameter of about 5 to 10 mm. After that, using an infrared moisture meter (FD240, manufactured by Kett Science Laboratory Co., Ltd.), in the moisture reference moisture measurement mode, the temperature is 105 ° C., the condition of Auto (the amount of change in the measured value is The volatile free water was measured by removing the volatilized free water measured in 30 seconds, assuming that it was within 0.05% as the final measured value and terminating the measurement).
(2) Measurement of granule water content 2 g of a sample was uniformly sprayed on a container made of aluminum having a diameter of 11.5 cm, and then measured under the same conditions as described above.
(3) Measurement of average particle diameter of water-insoluble powder The average particle diameter of the water-insoluble powder was measured with a laser diffraction / scattering particle size distribution analyzer (LA-920, manufactured by HORIBA), solvent: water, refractive index: 1. 2. Measured under conditions of circulation 3 min.

(4) Mass frequency of granules After vibrating for 5 minutes using a sieve defined in JIS Z8801-1 (established on May 20, 2000, final revised on November 20, 2006), the mass distribution under the sieve by the sieving method The 50% average diameter is calculated for, and this is the average particle diameter.
Specifically, using a sieve of 2000, 1400, 1000, 710, 500, 355, 250, 180, 125, 90, 63, 45 μm as defined in JIS Z8801-1, the sieves are stacked in order from a sieve with a small opening. Add 100 g of granules from the top of the top 2000 μm sieve, cover and attach to a low-tap sieve shaker (manufactured by HEIKO, tapping 156 times / minute, rolling: 290 times / minute), 5 minutes After vibrating, the mass of the granules remaining on each sieve and the saucer is measured, and the mass frequency (%) of the granules on each sieve is calculated.

(5) Average wet disintegration strength of granules First, after vibrating for 5 minutes using a sieve of 500, 355, 250, 180, 150, 125, 90, 63, 45 μm of JISZ8801-1, the particle size of 150 to 180 μm Granules were used as samples. Next, 15 g of a stainless steel sphere (diameter 4 mm), 3 g of a granule sample, and 30 mL of ion-exchanged water were put into a screw tube (manufactured by Maruemu Co., No. 6) and inverted once. Then, it was left still for 30 minutes, and rotated for 2 minutes 30 seconds at 75 r / min with a tablet wear tester (manufactured by Higaki Medical Science Co., Ltd.).
The obtained granule sample is filtered through a 150 μm sieve, dried at 105 ° C. for 30 minutes, and then cooled to room temperature with a desiccator. The 150 μm sieve is made into a micro-type electromagnetic vibrator (manufactured by Tsutsui Riken Kikai Co., Ltd., micro-type electromagnetic vibratory sieve). The shaker was shaken for 5.5 minutes with an instrument M-2) and then weighed. The value calculated by the following formula was defined as the average wet disintegration strength.
Average wet disintegration strength (%) = (granule mass remaining on 150 μm sieve ÷ initial sample mass) × 100

(6) Spray droplet diameter of sodium silicate aqueous solution The average droplet diameter (volume average particle diameter) of the sodium silicate aqueous solution was measured using a laser diffraction type particle size distribution measuring apparatus (manufactured by Malvern, Spray Tech). Specifically, the tip of the spray nozzle is placed at a location 30 cm away from the laser, and the sodium silicate aqueous solution is sprayed so that the laser penetrates the center of the spray droplet group perpendicular to the laser and spraying is continued for 30 seconds. And measured.

(7) Change in pH depending on presence or absence of granule 2g of granule-containing dentifrice was completely ground in a mortar and charged with 20mL of ion-exchanged water. The resulting liquid was measured with a pH meter and stabilized (about 1 The value at the time) was taken as the pH value of the granulated disintegrated dough.
After removing the dentifrice using a 45 μm sieve specified in JISZ8801-1, 2g of the dentifrice was taken, 20 mL of ion-exchanged water was added, and the resulting solution was measured with a pH meter. The value at the time (about 1 minute) was taken as the pH value of the granulated dough.

Examples 1-3
In the blending ratio shown in Table 1, heavy calcium carbonate (product name: ACE-25, manufactured by Calfine Co., Ltd.) as a water-insoluble powder material, and zinc oxide (product name: Sakai Chemical Industry Co., Ltd., product name: fine) as a zinc compound. Zinc oxide) was introduced into a 75 L drum granulator (φ40 cm × L60 cm) having a baffle plate, and the drum rotation speed was 30 r. p. Sodium silicate aqueous solution (manufactured by Fuji Chemical Industry Co., Ltd., trade name: No. 3 sodium silicate, solid content: 55.1%) was mixed externally while mixing under conditions of m / fluid number 0.2 / drum angle 12.6 ° Using one type two-fluid nozzle (manufactured by Atmax Co., Ltd.), the mixture was sprayed and granulated. The batch size was 8 kg. After the addition, mixing was continued for 1 minute, followed by discharging from the drum granulator and drying for 90 minutes at 80 ° C. using an electric shelf dryer. After drying, the granules were classified with a sieve having an opening of 500 μm to obtain a dentifrice granule that passed through the sieve.
Table 1 shows the granule production conditions, and Table 2 shows the composition and physical properties of the granules obtained.

Example 4
Granulation was carried out in the same manner as in Examples 1 to 3 except that heavy calcium carbonate (trade name: Calcy F # 9860, manufactured by Sankyo Seiko Co., Ltd.) was used as the water-insoluble powder material at the blending ratio shown in Table 1. Then, drying was performed at 100 ° C. for 15 minutes using a fluidized bed dryer (manufactured by Ogawara Seisakusho, trade name: Conduction Flow). After drying, the granules were classified with a sieve having an opening of 500 μm to obtain a dentifrice granule that passed through the sieve. The results are shown in Tables 1 and 2.

Comparative Example 1
75L drum granulator (φ40 cm × L60 cm) having a baffle plate with heavy calcium carbonate (manufactured by Sankyo Seiko Co., Ltd., trade name: Calcy F # 9860) as a water-insoluble powder material at the blending ratio shown in Table 1. The drum rotation speed is 30 r. p. Sodium silicate aqueous solution (manufactured by Fuji Chemical Industry Co., Ltd., trade name: No. 3 sodium silicate, solid content: 55.1%) was mixed externally while mixing under conditions of m / fluid number 0.2 / drum angle 12.6 ° Using one type two-fluid nozzle (manufactured by Atmax Co., Ltd.), the mixture was sprayed and granulated. The batch size was 8 kg. After the addition, mixing was continued for 1 minute, and then the product was discharged from the drum granulator, and dried at 80 ° C. for 90 minutes using an electric shelf dryer. After drying, the granules were classified with a sieve having an opening of 500 μm to obtain a dentifrice granule that passed through the sieve. The results are shown in Tables 1 and 2.

Comparative Example 2
Granules were produced under the same conditions as in Comparative Example 1 except that drying was performed at 100 ° C. for 30 minutes using a fluidized bed dryer (Freund Sangyo Co., Ltd., trade name: Spira Flow Lab). The results are shown in Tables 1 and 2.

Comparative Example 3
In the blending ratio shown in Table 1, heavy calcium carbonate (product name: ACE-25, manufactured by Calfine Co., Ltd.) as a water-insoluble powder material, and zinc oxide (product name: Sakai Chemical Industry Co., Ltd., product name: fine) as a zinc compound. Zinc oxide) was introduced into a 75 L drum granulator (φ40 cm × L60 cm) having a baffle plate, and the drum rotation speed was 30 r. p. Sodium silicate aqueous solution (manufactured by Fuji Chemical Industry Co., Ltd., trade name: No. 3 sodium silicate, solid content: 55.1%) was mixed externally while mixing under conditions of m / fluid number 0.2 / drum angle 12.6 ° Using one type two-fluid nozzle (manufactured by Atmax Co., Ltd.), the mixture was sprayed and granulated. The batch size was 8 kg. After the addition, mixing was continued for 1 minute, followed by discharging from the drum granulator and drying for 90 minutes at 80 ° C. using an electric shelf dryer. After drying, the granules were classified with a sieve having an opening of 500 μm to obtain a dentifrice granule that passed through the sieve. The results are shown in Tables 1 and 2.

Comparative Example 4
Zeolite as a water-insoluble powder material (trade name: Zeolite (powder), and zinc oxide as a zinc compound (trade name: fine zinc oxide) as a water-insoluble powder material at the mixing ratio shown in Table 1. And a sodium silicate aqueous solution (Fuji Chemical Industry Co., Ltd., trade name: No. 3 sodium silicate, solid content: 55.1%) and an appropriate amount of water, Disper blade (Ashizawa Niro Atomizer Co., Ltd., model: HS-P3) was mixed to obtain a water slurry, which was prepared by first introducing water into the mixing tank, then introducing an aqueous sodium silicate solution, and then introducing zinc oxide and zeolite. The batch size is 150 kg, and the obtained water slurry is spray-dried at a blowing temperature of 190 ° C. And classified in can 500μm sieve to obtain granules for dentifrice that has passed through the sieve. The results are shown in Tables 1 and 2.

From the results of Table 2, it can be seen from the comparison between Example 4 and Comparative Example 2 that have the same water content in the granules, the present application containing a zinc compound has high wet disintegration strength.
The granule of the present invention is excellent in wet disintegration strength, does not disintegrate during manufacture of the dentifrice, and maintains good disintegration strength even in the dentifrice.

[Evaluation of feeling of use by blending into dentifrice]
In order to evaluate the granules obtained in Examples and Comparative Examples, dentifrices having the composition shown in Table 3 below were prepared by a conventional method.
The preparation method of the dentifrice was performed in the step of blending the granules at the end after blending ingredients other than the granules at room temperature.
The dentifrice was left for 1 week after production to stabilize the fragrance.
Using the obtained dentifrice, 10 panelists (researchers engaged in the technical field for 5 years or more) brushed their teeth, and a questionnaire was used to evaluate the feeling of use.
(Evaluation item)
1. Awareness of astringency: (not astringent to astringent evaluation: 5 points, 4 points, 3 points, 2 points, 1 point)
2. Grain recognition: (feeling-not feeling evaluation: 5, 4, 3, 2, 1)
3. Degree of recognition of dirt removal: (Evaluation of falling to not falling: 5 points, 4 points, 3 points, 2 points, 1 point)
Table 4 shows the total score of the evaluation.

[Evaluation method of plaque removal effect]
A red lipstick (Orb Kao Co., Ltd .: RD305) was applied to the groove of the interdental model (five Pasteur pipettes of φ4 aligned and fixed). Thereafter, the excess lipstick was brushed (brushed) with a toothbrush (hair tip is ball Kao Co., Ltd .: normal) and a commercial dishwashing detergent until no red color appeared. Similarly, after applying red lipstick to the groove of the interdental model, 1 g of each of the toothpastes of Examples and Comparative Examples was taken on the interdental model, and the lipstick was brushed until it did not adhere to the toothbrush. . The lipstick remaining in the interdental model was ultrasonically washed with 90 mL of ethanol for 10 minutes, and the extract was subjected to absorbance measurement (Abs) at 540 nm. In addition, the light absorbency measurement value about the interdental model after brushing with the said dishwashing detergent was made into the standard light absorbency measurement value.
Dental plaque removal rate (%) = (standard absorbance measurement value−absorbance measurement value after brushing with dentifrice) / standard absorbance measurement value × 100 (%)
The evaluation is shown in Table 4.

[Evaluation of plaque formation inhibitory effect]
Nine healthy men in their 20s and 30s were evaluated as subjects according to the following procedure.
In order to prevent the order effect, the dentifrice was evaluated using a random crossover method, and both the operator and the subject were evaluated with a double blind that did not know the contents of the dentifrice.
・ Standard plaque formation amount: After scaling of plaque and calculus, the dental hygienist brushes using only a normal toothbrush for 2 minutes.
-Evaluation product plaque formation amount: 1g of dentifrice is applied to a toothbrush and brushing by the same dental hygienist is performed for 2 minutes.
(1) Stop brushing for 24 hours.
(2) The dental hygienist stains the plaque red (staining solution: Prospec), and photographs and measures the amount of plaque. (Measurement site: maxillary full jaw, mandibular left and right 4-7 cheek side)
(3) Each subject can brush freely (no dentifrice)
Measuring method: 1 tooth is divided into 5 and the height of plaque (the height of 0.5 mm unit using a periodontal pocket probe) on each divided surface is obtained.
Table 4 shows the plaque formation inhibition rates calculated by the following formulas of Examples 1, 2, and 4 and Comparative Examples 2 and 3, based on the plaque formation amount when brushing with only the toothbrush. The dentifrices of Examples 1, 2, and 4 showed a significantly higher plaque formation inhibitory effect than the dentifrices of Comparative Examples 2 and 3.
(Calculation method)
Plaque formation inhibition rate (%) = (Plate formation amount after 24 hours when brushed with toothbrush only-Plate formation amount after 24 hours when brushed with dentifrice) / Brush only with toothbrush Plaque formation after 24 hours x 100 (%)

The dentifrice which mix | blended the granule obtained in Examples 1-4 obtained the evaluation that it was excellent in the recognition degree in the oral cavity of a granule, and also the recognition degree of dirt removal.
On the other hand, the dentifrice which mix | blended the granule obtained by Comparative Examples 1-2, 4 was low in wet disintegration intensity | strength, and was inferior to the recognition degree in the oral cavity of a granule, and the recognition degree of dirt removal.
Moreover, the dentifrice which mix | blended the granule obtained by the comparative example 3 had many zinc amounts, Therefore The bitterness of zinc was strong and the recognition degree of astringency was not good.
In Comparative Example 4 obtained by the spray drying method, although the amount of zinc was not substantially different from that in Example 1, the bitterness of zinc was strong and the recognition of astringency was not good.

[Change in pH by adding to dentifrice]
Example 2 was stored at 40 ° C. for 1 week, and the dough from which the granules were extracted from these dentifrices was diluted 10-fold with ion-exchanged water, and completely in a mortar without removing the granules from these dentifrices. As a result of measuring the pH of the ground dough diluted 10-fold with ion exchange water, the pH of the granulated dough was 9.66 and the pH of the granulated disintegrated dough was 9.93.

Claims (10)

  A granule comprising a water-insoluble powder material, a zinc compound, and a silicate, wherein the silicate is one or two selected from sodium silicate and potassium silicate, and the content of zinc in the granule is 0 Granules for dentifrice, 5-7 mass%, silicate content 3-60 mass%, average wet disintegration strength 31-90%.   The granule for dentifrice of Claim 1 whose mass ratio (zinc / silicate) of zinc with respect to a silicate is 0.02-2.   The dentifrice granule according to claim 1 or 2, wherein the water-insoluble powder material is one or more selected from light calcium carbonate, heavy calcium carbonate, zeolite, and silica.   The dentifrice granule according to any one of claims 1 to 3, wherein a mass ratio of silicate to water-insoluble powder material (silicate / water-insoluble powder material) is 0.03 to 1.0.   The dentifrice granule according to any one of claims 1 to 4, wherein zinc is zinc oxide.   The dentifrice granule according to any one of claims 1 to 5, wherein the content of the water-insoluble powder material is 40 to 96 mass%.   The granule for dentifrice according to any one of claims 1 to 6, wherein the mass frequency of granules of 355 µm or more is 5 to 20 mass%, and the mass frequency of granules of 90 µm or less is 3 to 25 mass%.   A dentifrice containing the granule for dentifrice according to any one of claims 1 to 7. The manufacturing method of the granule for dentifrice in any one of Claims 1-7 which has the following process (1) and (2).
Step (1): Step of adding an aqueous solution of silicate to a mixture containing a water-insoluble powder material and a zinc compound and granulating Step (2): Step of drying the granules obtained in Step (1)   Production of dentifrice granules according to claim 9, wherein step (1) is a step of mixing and granulating a water-insoluble powder material, an aqueous solution of silicate and a zinc compound using a container rotating granulator. Method.