JP5486195B2 - Process for producing dentifrice granules - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a method for producing dentifrice granules and a dentifrice containing granules obtained by the 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, there are more diverse demands regarding the tactile sensation and tactile sensation of the granules in the oral cavity, and in order to meet these demands, it is necessary to adjust the granule strength each time according to the purpose and application. However, in order to obtain a specific granule strength, it has been necessary to examine the constituent components of the dentifrice granules and the preparation method of the granules each time, which requires much time and labor.

JP-A-1-299211

  The present invention relates to a method for producing a dentifrice granule capable of easily adjusting the granule strength of a dentifrice granule required according to the difference in purpose and application, and a dentifrice containing a granule obtained by the method. The issue is to provide.

The present inventors have found that the above problem can be solved by aging a dentifrice granule containing a water-insoluble inorganic binder and a water-insoluble powder material under specific conditions.
That is, the present invention provides the following [1] and [2].
[1] A method for producing a dentifrice granule having the following steps (1) and (2).
Step (1): Step of producing a dentifrice granule containing at least a water-insoluble powder material and a water-insoluble inorganic binder Step (2): The granule obtained in step (1) is treated at 28 to 100 ° C. for 10 hours. Step [2] for holding as described above A dentifrice containing granules obtained by the production method of [1].

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the granule for dentifrice which can adjust easily the granule intensity | strength of the dentifrice granule calculated | required according to the difference in the objective and the use, and the dentifrice containing the granule obtained by the method An agent can be provided.

2 is a scanning electron microscope (SEM) photograph showing a cross section of the granule obtained in Example 1. FIG. The outer shell is mainly composed of a water-insoluble inorganic binder (colloidal silica), and the central portion is mainly composed of calcium carbonate. It is the graph which showed the change of the increase rate of granule strength by the change of the temperature and time of aging in an Example and a comparative example.

The method for producing dentifrice granules of the present invention is characterized by having the following steps (1) and (2).
Step (1): Step of producing a dentifrice granule containing at least a water-insoluble powder material and a water-insoluble inorganic binder Step (2): The granule obtained in step (1) is treated at 28 to 50 ° C. for 10 hours. Steps to be held Hereinafter, components and steps used in the method of the present invention will be sequentially described.

[Water-insoluble powder material]
The water-insoluble powder material used in the present invention is not particularly limited, but calcium carbonate and / or silica having an average particle size of 0.1 to 100 μm is preferable. This water-insoluble powder material 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.
The water-insoluble powder material can be used singly or in combination of two or more. However, when the dentifrice is weakly alkaline and may affect stability, calcium carbonate reacts with other ingredients. If there is a risk of doing so, silica can be used alone.

When calcium carbonate is used as the water-insoluble powder material, the average particle size is preferably 0.1 to 20 μm, more preferably 0.5, from the viewpoint of not feeling the dirt removal power of the teeth after granule disintegration and feeling of foreign matter. 10 μm, more preferably 1 to 5 μm. 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.

When the silica is used as the water-insoluble powder material, the average particle size thereof is preferably 0.1 to 100 μm, more preferably 0.5 to 50 μm, still more preferably 1 to 20 μm, particularly preferably from the same viewpoint as described above. Is 5-15 μm.
In order to make the average particle size of the water-insoluble powder material within 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, it is possible to whiten the teeth by generating a sufficient polishing force to remove the colored pellicle strongly adsorbed on the tooth surface. 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 normal tooth dirt removal power (polishing power), the initial polishing power can be enhanced by granulation to increase the tooth dirt removal 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 is used to moderately collapse the water-insoluble powder material. This water-insoluble inorganic binder accumulates on the surface of the granules as the water evaporates during water slurry drying in step (II), which is described later, preferably when the water slurry is spray-dried, and forms an outer shell of the granules. 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.
The water-insoluble inorganic binder is not particularly limited, and a silicon compound having a hydroxyl group, an aluminum compound, a calcium compound, a magnesium compound, or the like can be used. Specific examples include colloidal silica, magnesium aluminate metasilicate, synthetic aluminum silicate, calcium silicate, bentonite, montmorillonite, kaolin, aluminum hydroxide gel, alumina sol, synthetic hydrotalcite, magnesium carbonate, magnesium oxide, hydroxide Water-insoluble inorganic compounds such as magnesium can be mentioned.
Among these, a silicon-based compound and an aluminum-based compound having a hydroxyl group are preferable, and colloidal silica, magnesium aluminate metasilicate, synthetic aluminum silicate, calcium silicate, alumina sol are particularly preferable from the viewpoint of operability in the spray granulation method. Are more preferable, and silicon-based compounds having a hydroxyl group such as colloidal silica are particularly preferable.
In the 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 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 preferably 1 to 90 nm, more preferably 3 to 70 nm, more preferably 5 to 50 nm, still more preferably 7 to 40 nm, and particularly preferably from the viewpoint of obtaining a desired disintegration strength. 8-30 nm.

The reason why a granule having a desired disintegration strength can be obtained by using a water-insoluble inorganic binder having such an average particle diameter is not clear, but is related to the outer shell of the granule formed by the water-insoluble inorganic binder. It is possible that In the present invention, it was found that the strength of the granules can be increased by further aging such granules under specific conditions. The reason why the granule strength increases due to aging is not clear, but as shown in Fig. 2, the increase rate of granule strength is higher as the temperature is higher, and the increase rate tends to be significantly higher at 28 ° C or higher. Therefore, it is considered that the binding force by the water-soluble inorganic binder forming the outer shell is strengthened by reaction or the like.
If the average particle size of the water-insoluble inorganic binder is 100 nm or less, the water-insoluble inorganic binder that moves to the granule surface as the water evaporates when the water slurry is dried in the step (II) described later is a water-insoluble powder material. It is expected that it will be easy to move through the gap. As a result, the thickness of the outer shell layer of the granules is increased, and it is assumed that granules having a desired disintegration strength can be obtained. Therefore, the upper limit of the average particle size of the water-insoluble inorganic binder is preferably 100 nm or less, more preferably 70 nm or less, more preferably 50 nm or less, more preferably 40 nm or less, still more preferably 30 nm or less, particularly preferably 20 nm or less. Become.
On the other hand, when the average particle size of the water-insoluble inorganic binder is 1 nm or more, it is presumed that the thickness of the outer shell layer of the granules is increased, and granules having a desired disintegration strength can be obtained. Therefore, the lower limit of the average particle size of the water-insoluble inorganic binder is preferably 1 nm or more, more preferably 3 nm or more, more preferably 5 nm or more, more preferably 7 nm or more, still more preferably 8 nm or more, particularly preferably 9 nm or more. Become.

[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 and water-insoluble fibers.
Examples of water-insoluble organic binders include oils and polymers that are water-insoluble and solvent-soluble, or water-insoluble by polyvalent metals, or resins such as thermoplastic resins and thermosetting resins that are commonly used in adhesives. Can be used.
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 Examples include homopolymers such as vinyl ether and α-olefin, and copolymers thereof, (ii) polysaccharides such as xanthan gum, dextrin, and gelatin, and derivatives thereof, and (iii) rubber-based latex.
Examples of the water-insoluble fiber include cellulose, hemicellulose, lignin, chitin, and the like. Among these, cellulose is particularly preferable from the viewpoint of removing plaque from granules.
The content of the water-insoluble fiber in the dentifrice granule is suitably 1 to 30% by mass, particularly 2 to 20% by mass from the viewpoint of plaque removability.

[Granule for dentifrice]
The content of the water-insoluble powder material in the dentifrice granule of the present invention is preferably 60 to 90% by mass, and 65 to 88% by mass from the viewpoint of disintegration, polishing power after granule disintegration and prevention of damage to teeth. Is more preferable, and 70-88 mass% is still more preferable.
The content of the water-insoluble inorganic binder in the dentifrice granule is preferably 10 to 40% by mass, more preferably 12 to 35% by mass, and still more preferably 12 to 30% by mass from the viewpoint of the disintegration strength of the granule. 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 granule for dentifrice of the present invention is produced by a method having the following steps (1) and (2).
Step (1): Step of producing a dentifrice granule containing at least a water-insoluble powder material and a water-insoluble inorganic binder Step (2): The granule obtained in step (1) is treated at 28 to 100 ° C. for 10 hours. Steps for holding as described above The method for producing the dentifrice granules in step (1) is not particularly limited, but according to the method including the following steps (I) and (II), it can be efficiently produced.
Step (I): A step of mixing a water-insoluble powder material and a water-insoluble inorganic binder to prepare a water slurry having a solid content of 40 to 70% by weight. Step (II): The water slurry obtained in Step (I) Drying to obtain granules containing 10 to 40% by weight (in terms of solid content) of the water-insoluble inorganic binder

[Step (I)]
Step (I) is a step of mixing a water-insoluble powder material and a water-insoluble inorganic binder to prepare a water slurry having a solid content of 40 to 70% by weight.
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 should be adjusted so that the solid content concentration in the water slurry is 40 to 70% by mass, including the water in the water-insoluble inorganic binder. Is preferable, and it is more preferable to adjust so that it may become 45-65 mass%, and it is still more preferable to adjust so that it may become 50-65 mass%.
Although mixing of each component in process (I) 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. At that time, the mixing temperature is preferably 5 to 40 ° C. 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 (II)]
Step (II) is a step of drying the water slurry obtained in step (I) to obtain granules containing 10 to 40% by weight of water-insoluble inorganic binder in terms of solid content.
The drying method is not particularly limited as long as it can remove water from the water slurry, but from the viewpoint of productivity, a method using a spray dryer or a fluidized bed dryer is preferable. From the viewpoint of sphericity and thermal efficiency, the spray drying method 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.

[Step (2)]
The dentifrice granule of the step (1) is obtained by the method including the steps (I) and (II). In the step (2), the granule obtained in the step (1) is 28 to 100 ° C. Hold for 10 hours or longer at aging.
The treatment in the step (1) is preferably 30 ° C. or higher, more preferably 32 ° C. or higher, further preferably 35 ° C. or higher from the viewpoint of shortening the holding time, and preferably 80 ° C. from the viewpoint of reducing the heat source cost. Below, more preferably 60 ° C. or less, more preferably 45 ° C. or less, and further preferably 40 ° C. or less.
The holding time can be appropriately determined depending on the selection of the holding time, the desired increase rate of the granule strength, etc., but from the viewpoint of productivity, storage cost, etc., preferably 1 to 50 days, more preferably 2 days to 40 days, more preferably 4 days to 35 days, particularly preferably 7 days to 30 days.
By the aging treatment in the step (2), the disintegration strength of the granules can be increased by about 120 to 200%. Here, when the water-insoluble powder material is calcium carbonate, it can be increased by about 130 to 200%. For this reason, according to this invention, according to the objective and a use, granule intensity | strength can be easily adjusted to the target range.

[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, Further, from the viewpoint of exerting polishing power without damaging the enamel of the teeth, it is preferably 6 to 20 g / piece (disintegrated with a load of 6 to 20 g per granule), more preferably 10 to 20 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 sufficient polishing power, and after granule disintegration, the polishing power is reduced so that the teeth are 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 usually used in dentifrices, such as binders, wetting agents, sweeteners, surfactants, preservatives, fragrances, medicinal ingredients, and other commonly used dentifrice abrasives, 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. 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, 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.

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
(1) Production of granules (step (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 Industries, Ltd., solid content: 30.5%, average particle size: 9.5 nm) and cellulose (trade name: KC Flock W-400G, manufactured by Nippon Paper Chemicals Co., Ltd., average particle size: about 24 μm) And water were mixed with a disperse blade (model: HS-P3, manufactured by Ashizawa Niro Atomizer Co., Ltd.) to obtain a water slurry (step (1)). The water slurry was prepared by first introducing water into the mixing tank, then adding colloidal silica, then adding calcium carbonate, further adding cellulose, and mixing (water slurry solids: 58 mass%).
The obtained water slurry was spray-dried at a blowing temperature of 190 ° C. to obtain granules having an average particle size of 268 μm and a disintegration strength of 12.0 g / piece. A scanning electron microscope (SEM) photograph showing a cross section of the obtained granule is shown in FIG.
(2) Aging process (step (2))
A part of the granules obtained by spray drying was placed in a polyethylene bag with a zipper (trade name: Unipack) and stored for 7 days under the condition of a temperature of 30 ° C.

Examples 2-6 and Comparative Examples 1-6
Table 1 shows the results of aging treatment of the granules obtained in step (1) of Example 1 under the conditions shown in Table 1.

Example 7
(1) Production of granules (step (1))
In the mixing ratio shown in Table 1, silica powder (trade name: Zeodent 124, manufactured by Sanki Co., Ltd., average particle size of about 9 μm), the colloidal silica (trade name: SNOWTEX S), and water are mixed with the disper blade ( Mixing was performed using a model: HS-P3) to obtain a 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 and mixing silica powder (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 size of 220 μm and a disintegration strength of 6.5 g / piece.
(2) Aging process (step (2))
It carried out similarly to Example 1 (2).

Examples 8-9 and Comparative Examples 7-8
Table 1 shows the results of aging treatment of the granules obtained in Step (1) of Example 7 under the conditions shown in Table 1.

In order to evaluate the granules obtained in Examples and Comparative Examples, it was confirmed that the granules could be blended in a dentifrice having the following composition.
(Dentifrice composition)
(mass%)
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

In order to make the results of Table 1 easier to understand, FIG. 2 shows changes in the rate of increase in granule strength due to changes in aging temperature and time in Examples and Comparative Examples.
From FIG. 2, it can be seen that if the holding time of aging is the same, the higher the holding temperature, the higher the increase rate of the granule strength.

Claims (8)

The manufacturing method of the granule for dentifrice which has the following process (1) and (2).
Step (1): Step of producing a dentifrice granule containing at least a water-insoluble powder material and a water-insoluble inorganic binder Step (2): The granule obtained in step (1) is treated at 28 to 100 ° C. for 10 hours. Step to hold above   The method for producing a dentifrice granule according to claim 1, wherein the water-insoluble inorganic binder has an average particle size of 1 to 90 nm.   The method for producing a dentifrice granule according to claim 1 or 2, wherein the water-insoluble inorganic binder is a silicon-based compound having a hydroxyl group.   The method for producing a dentifrice granule according to any one of claims 1 to 3, wherein the water-insoluble powder material is calcium carbonate and / or silica having an average particle size of 0.1 to 100 µm.   The manufacturing method of the granule for dentifrice in any one of Claims 1-4 hold | maintained in a process (2) for 1 to 50 days.   The method for producing a dentifrice granule according to any one of claims 1 to 5, wherein the granule of the step (1) is produced by a spray drying method.   The manufacturing method of the granule for dentifrices in any one of Claims 1-6 whose average particle diameter of a granule is 500 micrometers or less.   Dentifrice containing the dentifrice granule obtained by the manufacturing method in any one of Claims 1-7.