JP2010070458A - Method for producing dentifrice granules - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing dentifrice granules free from a sense of foreign matter touch and giving a comfortable sense of touch, and to provide a dentifrice containing the granules obtained by the production method. <P>SOLUTION: There are provided the method for producing the dentifrice granules, characterized by comprising the following processes (1) and (2); the process (1): a process for mixing calcium carbonate and/or silica having an average particle diameter of 0.1 to 100 μm with a water-insoluble inorganic binder having an average particle diameter of 7 to 40 nm to prepare aqueous slurry having a solid content of 50 to 70 wt.%, and the process (2): a process for drying the aqueous slurry obtained in the process (1) to obtain the granules containing the water-insoluble inorganic binder in a content of 12 to 40 wt.% (converted into a solid content). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for producing dentifrice granules and a dentifrice containing granules obtained by the production method.

In recent years, dentifrices containing granules that can effectively remove dental plaque that causes tooth decay and periodontal disease and can feel the effect 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.
Known binders for these granules include water-soluble binders such as methylcellulose and carboxymethylcellulose, and organic binders such as wax. The use of organic binders can increase the particle strength relatively easily, but on the other hand, the elasticity of the granules increases, so the feel when the granules disintegrate changes, and the mouth feels uncomfortable. There was a problem.

Therefore, the present applicant has proposed a dentifrice containing granules obtained by binding a water-insoluble powder material such as zeolite with a water-insoluble inorganic binder as a dentifrice that has solved such problems (see Patent Document 1). ). This dentifrice is made by granulating a water-insoluble powder material with a water-insoluble binder and blending granules that maintain a certain size and strength. In addition, there is almost no foreign material feeling and the polishing power is enhanced.
However, regarding the tactile sensation and tactile sensation of the granules in the oral cavity, it has been desired to develop a method for producing a dentifrice granule that is more excellent than conventional ones.

JP-A-1-299211

  The present invention relates to a method for producing a granule for dentifrice having a more comfortable granule feel without foreign material feeling in calcium carbonate and / or silica-based granule, and a dentifrice containing the granule obtained by the production method It is an issue to provide.

The present inventors use calcium carbonate and / or silica having a specific particle size as a water-insoluble powder material, and prepare a high-concentration water slurry in combination with a water-insoluble inorganic binder having a specific particle size. The present inventors have found that the above-mentioned problems can be solved by drying this into granules.
That is, the present invention provides the following [1] and [2].
[1] A method for producing a dentifrice granule comprising the following steps (1) and (2).
Step (1): Calcium carbonate and / or silica having an average particle size of 0.1 to 100 μm and a water-insoluble inorganic binder having an average particle size of 7 to 40 nm are mixed, and water having a solid content of 50 to 70% by weight. Step of preparing slurry Step (2): drying the water slurry obtained in step (1) to obtain granules containing 12 to 40% by weight (in terms of solid content) of the water-insoluble inorganic binder [ 2] A dentifrice containing granules obtained by the production method of [1].

  According to the method of the present invention, it is possible to produce calcium carbonate and / or silica-based dentifrice granules having a more comfortable granule feel without the presence of foreign matter in the oral cavity due to the improved disintegration strength of the granules. it can. Further, according to the method of the present invention, calcium carbonate and / or silica dentifrice granules having a good cleaning effect can be produced. Furthermore, by using the method of the present invention, calcium carbonate and / or silica dentifrice granules can be produced with high productivity.

The method for producing a dentifrice granule according to the present invention includes the following steps (1) and (2).
Step (1): Calcium carbonate and / or silica having an average particle size of 0.1 to 100 μm (hereinafter sometimes collectively referred to as “water-insoluble powder material”) and water-insoluble having an average particle size of 7 to 40 nm Step of mixing an inorganic binder to prepare a water slurry having a solid content of 50 to 70% by weight Step (2): The water slurry obtained in the step (1) is dried to obtain 12 of the water-insoluble inorganic binder. Step of obtaining granules containing -40% by weight (in terms of solid content) Hereinafter, components and steps used in the method of the present invention will be described in order.

[Calcium carbonate and / or silica having an average particle size of 0.1 to 100 μm]
Calcium carbonate and / or silica having an average particle size of 0.1 to 100 μm used in the present invention is a water-insoluble powder material and functions as a tooth abrasive or cleaning agent. Among these, calcium carbonate is more preferable because it is weakly alkaline and has excellent cleaning effects such as plaque removal power.
Calcium carbonate and / or silica can be used alone or in combination. However, when the dentifrice is weakly alkaline and may affect stability, calcium carbonate reacts with other ingredients. If there is a risk, silica can be used alone.

The average particle diameter of calcium carbonate is preferably 0.1 to 20 μm, more preferably 0.5 to 10 μm, and still more preferably 1 to 5 μm, from the viewpoint of not feeling the dirt removal ability of the teeth after granule disintegration and feeling of foreign matter. It is. This average particle diameter can be measured with a laser diffraction / scattering particle size distribution analyzer.
The specific surface area of the calcium carbonate, from the viewpoint of stain removal force is preferably ^{1~10m 2 / g, 2~8m 2 /} g is more preferable. This specific surface area can be determined by the BET method using N ₂ gas adsorption.

The average particle diameter of the silica is 0.1 to 100 μm from the same viewpoint as described above, preferably 0.5 to 50 μm, more preferably 1 to 20 μm, and still more preferably 5 to 15 μm.
In order to set the average particle size of the water-insoluble powder material in the above range, it is possible to adjust the average particle size within the above range by granulating low abrasive particles having an average particle size of 10 μm or less. By adjusting in this way, the tooth can be whitened by generating a sufficient polishing force to remove the colored pellicle strongly adsorbed on the surface of the tooth. In addition, it is possible to give a feature that the teeth are not damaged even with a long brushing operation (low harm).
Even if the average particle size is 10 μm or more, which is used in expectation of the normal tooth dirt removing power (abrasive power), the initial abrasive power can be enhanced by granulation to increase the tooth dirt removing power. It can be considered that, with the tooth brushing operation, the granules disintegrate to primary particles, so that the teeth are hardly damaged.

[Water-insoluble inorganic binder]
In the present invention, the water-insoluble inorganic binder (water-insoluble inorganic compound) is used for appropriately disintegrating calcium carbonate and / or silica granules. This water-insoluble inorganic binder accumulates on the surface of the granule as the water evaporates during water slurry drying in step (2) described below, preferably when the water slurry is spray-dried, and forms an outer shell of the granule. Has the function of increasing the strength of the granules. By adjusting the kind and amount of the water-insoluble inorganic binder, the disintegration strength of the granules can be adjusted as appropriate.
Specific examples of the water-insoluble inorganic binder are not particularly limited, but colloidal silica, magnesium aluminate metasilicate, bentonite, montmorillonite, kaolin, synthetic aluminum silicate, calcium silicate, aluminum hydroxide gel, alumina sol , Magnesium carbonate, synthetic hydrotalcite, magnesium oxide, magnesium hydroxide and the like.
Among these, silicon compounds are preferable, and colloidal silica, magnesium aluminate metasilicate, and synthetic aluminum silicate are more preferable, and colloidal silica is particularly preferable from the viewpoint of operability in the spray granulation method.
In the above examples of the water-insoluble inorganic binder, there is a substance containing water such as colloidal silica. In the present invention, the water-insoluble inorganic binder means a substantial inorganic binder excluding water. To do.

The above water-insoluble inorganic binder can be used alone, but can also be used in combination of two or more. For example, a binder (for example, colloidal silica or alumina sol) that has strong adhesiveness and improves granule strength, and a binder (for example, magnesium aluminate metasilicate or synthetic aluminum silicate) that improves the formability of granules. By using in combination, it is possible to obtain various granules in which the kind and amount of the powder material are freely changed while maintaining a predetermined strength.
The average particle size of the water-insoluble inorganic binder is 7 to 40 nm, preferably 8 to 30 nm, more preferably 9 to 20 nm, from the viewpoint of obtaining a desired disintegration strength.
The reason why a granule having a desired disintegration strength is obtained with such an average particle diameter is not clear,
It may be related to the outer shell of the granules formed by the water-insoluble inorganic binder.
When the average particle size of the water-insoluble inorganic binder is increased, the water-insoluble inorganic binder that moves to the granule surface as the water evaporates is dried with calcium carbonate and / or 0.1 to 0.1 when the water slurry is dried in the step (2). It is expected that it is difficult to move through the gap of 100 μm silica. As a result, the thickness of the outer shell layer of the granule becomes thin, and it is assumed that a granule having a desired disintegration strength cannot be obtained. Therefore, the preferable average particle size of the water-insoluble inorganic binder is 40 nm or less, more preferably 30 nm or less, and more preferably 20 nm or less.
On the other hand, when the average particle size of the water-insoluble inorganic binder is reduced, this time, due to the small average particle size, the thickness of the outer shell layer of the granule becomes thin, and a granule having the desired disintegration strength cannot be obtained. It is guessed. Therefore, the average particle size of the preferred water-insoluble inorganic binder is 7 nm or more, more preferably 8 nm or more, and more preferably 9 nm or more.

[Other ingredients]
In the present invention, a binder other than the water-insoluble inorganic binder can be added within a range not impairing the object of the present invention. Examples of other binders include water-insoluble organic binders.
As the water-insoluble organic binder, use oils and polymers that are water-insoluble and solvent-soluble, or become water-insoluble by polyvalent metals, or thermoplastic resins and thermosetting resins generally used for adhesives. Can do.
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) acrylic acid, acrylic acid ester, methacrylic acid, methacrylic acid ester, hydroxymethacrylic acid ester, styrene, vinyl acetate, vinyl pyrrolidone, maleic acid ester, methyl Homopolymers such as vinyl ether and α-olefin, and copolymers thereof, etc. (ii) Polysaccharides such as methylcellulose, ethylcellulose, hydroxyethylcellulose, carboxyethylhydroxyethylcellulose, carrageenan, xanthan gum, dextrin, gelatin, and derivatives thereof (Iii) rubber latex and the like.

[Granule for dentifrice]
The content of the water-insoluble powder material (calcium carbonate and / or silica) in the dentifrice granule of the present invention is 60 to 88 from the viewpoint of disintegration, polishing power after granule disintegration and prevention of damage to teeth. % By mass is preferable, and 70 to 88% by mass is more preferable.
The content of the water-insoluble inorganic binder in the dentifrice granules is preferably 12 to 40 mass%, more preferably 12 to 30 mass%, from the viewpoint of the disintegration strength of the granules. Further, the content of the water-insoluble organic binder which is an optional component is preferably 3% by weight or less, more preferably 2% by weight or less, and most preferably not blended from the viewpoint of disintegration feeling.

[Method for producing granules for dentifrice]
The method for producing a dentifrice granule of the present invention includes the following steps (1) and (2).
[Step (1)]
In step (1), calcium carbonate and / or silica having an average particle size of 0.1 to 100 μm and a water-insoluble inorganic binder having an average particle size of 7 to 40 nm are mixed, and the solid content is 50 to 70% by weight. This is a step of preparing a water slurry.
When the water-insoluble inorganic binder is colloidal silica or the like, since water is contained in the water-insoluble inorganic binder, it may not be necessary to add further water in some cases. From the viewpoint of adjusting the apparent viscosity, it is preferable to add water separately.
From the viewpoint of obtaining productivity and desired granule strength, the amount of water is adjusted so that the solid content concentration in the water slurry, including water in the water-insoluble inorganic binder, is 50 to 70% by mass. Is preferable, and it is more preferable to adjust so that it may become 50-65 mass%.
Although mixing of each component in a process (1) can be performed by a well-known method, any of a batch type, a continuous type, and a semibatch type may be sufficient, for example. In that case, the mixing temperature should just be about normal room temperature, and 5-40 degreeC is preferable. The mixing time is not particularly limited as long as the solid content concentration becomes uniform to some extent, but is usually 10 to 300 minutes, preferably 15 to 120 minutes.

[Step (2)]
Step (2) is a step of drying the water slurry obtained in step (1) to obtain granules containing 12 to 40% by weight of water-insoluble inorganic binder in terms of solid content.
As the drying device, a known device can be used as long as it can remove water from the water slurry, but from the viewpoint of productivity, a spray dryer or a fluidized bed dryer is preferable. From the viewpoint of sphericity and thermal efficiency, a spray dryer is more preferable. Moreover, it is preferable to employ a pressure spray nozzle as the water slurry atomizer.

The counter-current spray drying tower is a device that atomizes water slurry from the top of the drying tower, atomizes it, supplies hot air from the bottom of the drying tower, brings them into countercurrent contact, and takes out the dried granules from the bottom of the drying tower. . The gas temperature in the drying tower is preferably 100 to 250 ° C, more preferably 120 to 230 ° C, and still more preferably 140 to 210 ° C, from the viewpoint of thermal efficiency. The physical properties of the granules obtained by spray drying can be controlled by adjusting the water slurry composition, spray drying conditions, and the like.
In the drying process, particularly the spray drying process, when the water slurry is sprayed, droplets are formed in which the water-insoluble powder material and the water-insoluble inorganic binder are integrated, but when the droplets are dried, It is considered that the droplets become smaller as the water evaporates, and at the same time, the water-insoluble inorganic binder moves and accumulates from the inside of the droplets to the surface of the droplets as the water evaporates to form the outer shell of the granules. That is, the granule obtained in this way has a structure in which the water-insoluble inorganic binder is present in the vicinity of the surface more than the inside, so that it is considered that a granule having an appropriate disintegration strength can be obtained.

[Characteristics of dentifrice granules]
The disintegration strength of the dentifrice granule, when blended in a dentifrice, can feel the granule in the mouth and can recognize the plaque removal effect, but feel almost no foreign body, In addition, from the viewpoint of exerting polishing power without damaging the tooth enamel, it is preferably 6 to 20 g / piece (disintegrated with a load of 6 to 20 g per granule), more preferably 6 to 15 g / piece, more preferably 10.5 to 15 g.
The disintegration strength is represented by an average value obtained by measuring 10 to 20 granules near the average particle diameter using a micro compression tester (manufactured by Shimadzu Corporation, trade name: MCTM-500).
The average particle size of the dentifrice granules obtained by the method of the present invention has a sufficient abrasive force, and after granule disintegration, the abrasive force decreases so that the tooth is not damaged even during a long brushing operation. Therefore, it is preferably 500 μm or less, more preferably 50 to 500 μm, and still more preferably 75 to 300 μm.
The average particle diameter is calculated by using a JIS standard sieve to calculate a number of average diameters for the weight distribution by the sieving method, and this is used as the average particle diameter.
Granules having the above average particle diameter and disintegration strength can be produced by appropriately changing the type, blending amount, and production conditions of the water-insoluble inorganic binder.

[Dentifrice]
The granule obtained by the method of the present invention is preferably blended in the dentifrice in an amount of 1 to 50% by weight, more preferably 3 to 30% by weight. 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. Has characteristics.
The dentifrice can be prepared by a conventional method. At this time, other ingredients commonly used in dentifrices, such as binders, wetting agents, sweeteners, surfactants, preservatives, fragrances, medicinal ingredients, and other commonly used abrasives for dentifrice, 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 xylitol, maltite, lactit, erythritol, and the like. Sweetening agents include saccharin sodium, stepioside, timertin, asparatylphenylalanine. A methyl ester etc. are mentioned.

Examples of the surfactant include hydrochloric acid salts of acyl amino acids such as sodium acyl glutamate and sodium acyl sarcosinate, salts of alkyl phosphoric acids such as sodium lauryl phosphate, sucrose fatty acid esters, sorbitan fatty acid esters, polyoxyethylene fatty acid esters, and the like. .
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, Elemi, 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.

Medicinal ingredients include caries preventive agents, antimicrobial agents, vitamins, enzymes, anti-inflammatory agents, and the like. Specifically, sodium fluoride, tin fluoride, sodium monofluorophosphate, vitamin E, vitamin C, Dextranase, mutanase, sodium chloride, glycyrrhetinic acid, azulene, β-glycyrrhetinic acid, dihydric cholesterol, chlorhexidine, epidihydric cholesterol, isopropylmethylphenol, trichlorocarbanilide, halocarban, hinokitiol, allantoin, tranexamic acid, propolis And cetylpyridinium chloride.
The said component can be used individually or in combination of 2 or more types.

Example 1
Calcium carbonate (trade name: Toyo White, manufactured by Toyo Denka Kogyo Co., Ltd., average particle diameter of about 2 μm, specific surface area of about 4 m ² / g) and colloidal silica (trade name: Snowtex S, Nissan) Chemical Industry Co., Ltd., solid content: 30.5%, average particle size: 9.5 nm) and water are mixed with a disper blade (model: HS-P3, manufactured by Ashizawa Niro Atomizer Co., Ltd.), and water slurry (Step (1)). In addition, water slurry preparation was performed by throwing water into a mixing tank first, then throwing colloidal silica, and then adding calcium carbonate and mixing (water slurry solid content: 52 mass%).
The obtained water slurry was spray-dried at a blowing temperature of 190 ° C. to obtain granules having an average particle diameter of 217 μm and a disintegration strength of 10.4 g / piece. A scanning electron microscope (SEM) photograph showing a cross section of the obtained granule is shown in FIG.

Examples 2-5
In the same manner as in Example 1, the mixture was mixed in the blending ratio, apparatus, and addition order shown in Table 1 to obtain a water slurry. This water slurry was spray-dried in the same manner as in Example 1 to obtain granules. The results are shown in Table 1.
Example 6
In Example 1, cellulose (trade name: KC Flock W-400G, manufactured by Nippon Paper Chemical Co., Ltd., average particle size: about 24 μm) was further added as a water-insoluble organic binder, and the mixing ratio shown in Table 1 was obtained. Except for the above, a water slurry was prepared in the same manner as in Example 1, and spray-dried to obtain granules. The results are shown in Table 1.
Example 7
In Example 1, colloidal silica (trade name: Snowtex S) was changed to colloidal silica (trade name: Snowtex 30, manufactured by Nissan Chemical Industries, solid content: 30.5%, average particle size: 15 nm). A water slurry was prepared in the same manner as in Example 1 except that the blending ratio shown in Table 1 was used, and spray-dried to obtain granules. The results are shown in Table 1.
Example 8
In Example 1, calcium carbonate (trade name: Toyo White) was changed to silica powder (trade name: Zeodent 124, manufactured by Sanki Co., Ltd., average particle size: about 9 μm), and the blending ratio shown in Table 1 was used. Prepared a water slurry in the same manner as in Example 1, and spray-dried to obtain granules. The results are shown in Table 1.

Comparative Example 1
In Example 1, colloidal silica (trade name: Snowtex S) was changed to colloidal silica (trade name: Snowtex 20L, manufactured by Nissan Chemical Industries, solid content: 20.5%, average particle size: 45 nm). Moreover, except having added dextrin before calcium carbonate, the water slurry of the mixture ratio shown in Table 1 was prepared like Example 1, and it spray-dried and obtained the granule. The results are shown in Table 1.
Comparative Examples 2-3
In Example 1, colloidal silica (trade name: Snowtex S) was changed to colloidal silica (trade name: Snowtex CXS-9, manufactured by Nissan Chemical Industries, Ltd., solid content: 14.5%, average particle size: 4.3 nm. The slurry was prepared in the same manner as in Example 1 except that the mixing ratio shown in Table 1 was used, and the mixture was spray-dried to obtain granules. The results are shown in Table 1.

In order to evaluate the granules obtained in Examples and Comparative Examples, the granules were blended in a dentifrice having the following composition. 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.
(Dentifrice composition)
Granules 15.0 (%)
Polyethylene glycol 10.5 (%)
Sorbit liquid 30.0 (%)
Iota Carrageenan 2.0 (%)
Sodium lauryl sulfate 1.2 (%)
Saccharin sodium 0.1 (%)
Paraben 0.1 (%)
Fragrance 0.8 (%)
Water remaining
Total 100.0 (%)

As a result, the granules obtained in Examples 1 to 8 were superior in disintegration strength compared to the granules obtained in Comparative Examples 1 to 3. Moreover, the dentifrice which mix | blended the granule obtained in Examples 1-8 is excellent in the touch in the oral cavity of a granule, when it mix | blends with a dentifrice, the touch of a granule is excellent, and the cleaning effect of a tooth is also excellent. Evaluation was obtained.
In Comparative Example 1, since the average particle diameter of the water-insoluble inorganic binder (colloidal silica) used was too large, the disintegration strength of the granules was insufficient even when the content was increased. On the other hand, in Comparative Examples 2 and 3, since the average particle size of the water-insoluble inorganic binder (colloidal silica) used was small, the disintegration strength of the granules was insufficient.

2 is a scanning electron microscope (SEM) photograph showing a cross section of the granule obtained in Example 1. FIG. The outer shell is a water-insoluble inorganic binder (colloidal silica), and the central portion is mainly calcium carbonate.

Claims (7)

A method for producing a dentifrice granule comprising the following steps (1) and (2).
Step (1): Calcium carbonate and / or silica having an average particle size of 0.1 to 100 μm and a water-insoluble inorganic binder having an average particle size of 7 to 40 nm are mixed, and water having a solid content of 50 to 70% by weight. Step of preparing slurry Step (2): Drying the water slurry obtained in step (1) to obtain granules containing 12 to 40% by weight (in terms of solid content) of the water-insoluble inorganic binder.   The method for producing a dentifrice granule according to claim 1, wherein the drying in the step (2) is spray drying.   The method for producing a dentifrice granule according to claim 1 or 2, wherein the disintegration strength of the granule is 6 to 20 g / piece.   The method for producing a dentifrice granule according to any one of claims 1 to 3, wherein the water-insoluble inorganic binder has a structure in which the water-insoluble inorganic binder is present more in the vicinity of the surface than in the interior.   The method for producing a dentifrice granule according to any one of claims 1 to 4, wherein the water-insoluble inorganic binder is colloidal silica.   The manufacturing method of the granule for dentifrices in any one of Claims 1-5 whose average particle diameter of a granule is 500 micrometers or less.   A dentifrice containing granules obtained by the production method according to claim 1.

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