JP3479823B2 - Toothpaste composition - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a dentifrice composition having excellent shape retention on a toothbrush and dispersibility in the oral cavity.

[0002]

2. Description of the Related Art Conventionally, the problems to be solved by the invention
Dentifrice compositions having excellent shape retention on the toothbrush and dispersibility in the oral cavity are disclosed in JP-A-5-170631 and JP-A-6-23972.
It is proposed in Japanese Patent Publication No. 1 and the like.

However, there is still room for studying the shape retention and oral dispersibility of toothpaste on the toothbrush, and the development of a dentifrice composition having excellent shape retention and oral dispersibility on the toothbrush. Is desired.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a dentifrice composition having excellent shape retention on the toothbrush and dispersibility in the oral cavity.

[0005]

Means for Solving the Problems and Modes for Carrying Out the Invention As a result of extensive studies conducted by the present inventor to achieve the above-mentioned object, as a binder, xanthan gum and sodium polyacrylate were used in combination with an abrasive. As the silica-based polishing agent, the mixing ratio of water and the thickening agent is 1.5 by weight.
With the above composition, the viscosity at 20 rpm at 25 ° C. measured with a BH type viscometer is 100 to 250 poise, and the shear rate at 25 ° C. measured with a double cylinder viscometer is 64 m.
It has been found that a dentifrice composition having a shear stress at in ^-1 hour that is not more than twice the shear stress at a shear rate of 8 min ^-1 has excellent shape retention on a toothbrush and dispersibility in the oral cavity.

That is, generally, the viscosity of a dentifrice composition is defined by the viscosity by a BH viscometer, and the lower the viscosity, the higher the dispersibility in the oral cavity, whereas the shape retention of the dentifrice composition decreases. When the toothbrush composition is placed on the toothbrush, the toothbrush drips and the usability is greatly deteriorated.

On the other hand, the dentifrice composition is a pseudoplastic fluid among non-Newtonian fluids when its rheological properties are examined with a double cylinder type viscometer. Pseudoplastic fluid has a strong bonding action due to intermolecular stress in a stationary state and exhibits a solid-like property. However, when a force is applied (the shear rate is increased), the bond is broken and the liquid-like property is exhibited. Generally, the stress at which this force breaks is called the yield value, and the magnitude of the stress at this time is related to the shape retention of the dentifrice composition. Further, the rate of change in stress when the shear rate is changed represents the easiness of breaking of the bond between the constituent molecules of the dentifrice composition, and is related to the dispersibility of the dentifrice composition. But,
If the binding force is relatively weak, that is, the viscosity is low, the yield value is not clearly shown.

Therefore, the present inventor examined the results of measurement with a BH type viscometer and a double cylinder type viscometer in order to clarify the rheological properties of a dentifrice composition having excellent shape retention and dispersibility. . As a result, the specific binder and abrasive as described above, and the specific amount of the thickener are contained in the BH type viscometer.
The viscosity of 20rpm at ° C. is 100 to 250 poise, shear stress at a shear rate 64Min ^-1 is less than 2 times the shear stress at a shear rate 8min ^-1 at 25 ° C. as measured by double cylinder viscometer A toothpaste composition with rheological properties has excellent shape retention on a toothbrush despite its low viscosity, and it does not soak into the brush portion of the toothbrush or drip from the head portion, and the required amount can be easily taken out. In addition, it was found that the dispersibility in the oral cavity is excellent and the feeling of use is good.

Further, it has been found that when a fluorine compound is added to the above dentifrice composition as an active ingredient, the compounding effect of the fluorine compound can be sufficiently exhibited due to its rheological properties.
The present invention has been completed.

Therefore, the present invention comprises a silica-based abrasive, a binder using xanthan gum and sodium polyacrylate in combination, a thickener, and water, and water and a thickener. Is 20 to 25 rpm at 25 ° C. measured by a BH-type viscometer with a composition ratio of 1.5 to 2.2 by weight.
Viscosity 100 to 250 poise, wherein the shear stress of at shear rate 64Min ^-1 at 25 ° C. as measured by double cylinder viscometer is not more than 2 times the shear stress at a shear rate 8min ^-1 A dentifrice composition is provided.

The present invention will be described in more detail below. The dentifrice composition of the present invention can be prepared as a toothpaste, a liquid dentifrice, a moisturizing dentifrice, etc., and includes a binder, an abrasive, a thickener and water. Further, it contains various optional components and has a viscosity in a specific range.

Here, as the binder, it is necessary to mix xanthan gum and sodium polyacrylate in order to achieve a viscosity in a specific range to be described later and to stabilize the composition. , 2: 1 to 1:10 by weight,
Particularly, 1: 1 to 1: 8 is preferable.

In the present invention, in addition to xanthan gum and sodium polyacrylate, other binders can be blended if necessary so long as the effects of the present invention are not impaired. Specific examples of such a binder include carboxymethyl cellulose alkali metal salt, methyl cellulose, hydroxyethyl cellulose, cellulose derivative such as sodium carboxymethyl hydroxyethyl cellulose, alkali metal alginate such as sodium alginate, propylene glycol alginate ester, carrageenan, tragacanth gum, and the like. Karaya gum, gum arabic,
Examples thereof include gums such as guar gum, synthetic binders such as polyvinyl alcohol and polyvinylpyrrolidone, inorganic binders such as aluminum silica gel and laponite, and various binders used for ordinary dentifrice.

The total content of the binder is usually 0.1 to 5% by weight, preferably 0.5 to 2% by weight based on the total weight of the composition in order to achieve the following viscosity.

Examples of the thickener include glycerin, propylene glycol, ethylene glycol, polyethylene glycol, 1,3-butylene glycol,
Known thickening agents used for dentifrice such as sugar alcohols such as sorbit, xylit, and lactit can be used. One of these thickeners may be used alone, or two or more thereof may be used in combination.

The compounding amount of the thickening agent is usually 10 based on the whole composition.
It is desirable that the content is ˜45% by weight, particularly 20 to 35% by weight, but the lubricity is adjusted so that the weight ratio of water to thickener in the composition is 1.5 to 2.2 in order to achieve the above viscosity. It is necessary to add an amount that does not impair the above. When the ratio of water to the thickener is less than 1.5, a satisfactory viscosity cannot be obtained, and the object of the present invention cannot be achieved.

Further, in the present invention, as the abrasive,
A silica-based abrasive such as precipitated silica, silica gel, aluminosilicate, or zirconosilicate that can secure a high cleaning power with a relatively small amount is used in order to achieve a viscosity in a specific range described later.

Further, in the present invention, in addition to the above silica-based abrasives, other abrasives such as dibasic calcium phosphate dihydrate and anhydride, calcium pyrophosphate, calcium carbonate, insoluble potassium metaphosphate, titanium oxide, zeolite, and silica. Aluminum oxide, zirconium silicate, synthetic resin-based abrasives and the like can be used to the extent that the effects of the present invention are not impaired.

In the composition of the present invention, when only a silica-based abrasive is used as the abrasive, the preparation may become translucent. When it is made opaque, the silica-based abrasive and titanium oxide are used. Is preferably used in combination.

The content of the above abrasive is usually preferably 5 to 30% by weight based on the total weight of the composition.

The dentifrice composition of the present invention contains the above-mentioned components and is 20 r at 25 ° C. measured by a BH type viscometer.
pm viscosity is 100-250 poise, preferably 140
~ 210 poise and measured with a double cylinder viscometer 2
5 shear stress at a shear rate 64Min ^-1 at ℃ is more than twice the shear stress at a shear rate 8min ^-1, and preferably 1.8 times or less. 20 rp measured with BH type viscometer
When the viscosity of m is less than 100 poise, the shape retention property is deteriorated, and when it exceeds 250 poise, satisfactory dispersibility in the oral cavity cannot be obtained and the usability is deteriorated. Further, when the shear stress at a shear rate 64Min ^-1 measured by double cylinder viscometer exceeds twice the shear stress at a shear rate 8min ^-1, poor shape retention and orodispersible. As the double cylinder type viscometer, specifically, a Haake viscometer (manufactured by Haake Co.) is preferably used.

The viscosity in the specific range is determined by the types and amounts of the components of the composition, particularly the binder, as described above.
This can be achieved by appropriately selecting the type of abrasive and the compounding ratio of water and thickener.

In the dentifrice composition of the present invention, in addition to the above-mentioned components, appropriate components can be blended depending on the kind.
As the optional component, for example, a surfactant, a sweetening agent, a flavoring agent,
Colorants, preservatives, viscosity modifiers, various active ingredients and the like can be added. In any case, these optional components can be used in a usual amount.

Since the dentifrice composition of the present invention is excellent in dispersibility in the oral cavity, the feeling of use in the oral cavity is very good,
In particular, when a fluorine compound is blended as an active ingredient, the blending effect of the fluorine compound can be sufficiently exhibited due to the rheological properties of the preparation.

In this case, examples of the fluorine compound include sodium fluoride, stannous fluoride, sodium monofluorophosphate and the like, and the compounding amount thereof is 100 to 2000 ppm as a fluorine ion, particularly 500 to 1500 p.
pm is preferred.

The container for containing the dentifrice composition of the present invention is not particularly limited, but a container having a mouth portion having a diameter of 1 to 5 mm is preferably used, and when such a container is used,
Especially, a toothbrush having a compact head portion can easily take out a necessary amount.

[0027]

EFFECTS OF THE INVENTION The dentifrice composition of the present invention is excellent in shape retention on a toothbrush despite having low viscosity and does not soak into the brush portion of the toothbrush. However, the required amount can be easily taken out without dripping. In addition, it is also excellent in dispersibility in the oral cavity, and not only has a good feeling in the oral cavity, but when a fluorine compound is added as an active ingredient, it exhibits a high fluorine compound addition effect due to the rheological properties of the formulation. You can

[0028]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples. In addition,% in each example is% by weight. [Examples and Comparative Examples] Toothpaste compositions having the compositions shown in Tables 1 and 2 were prepared and evaluated by the following methods. The results are also shown in Tables 1 and 2. (1) Viscosity: The viscosity (η ₂₀ ) at 25 ° C. and 20 rpm was measured with a BH type viscometer (manufactured by Tokyo Keiki Seisakusho). (2) Shear stress: Shear rate 0-64 min ^{-1 at} 25 ° C. using a HAAKE viscometer (manufactured by Haake)
The shear stress at time was measured, and the shear stress at 8 min ⁻¹ hour (τ ₈ ) and the shear stress at ₆₄ min ⁻¹ (τ ₆₄ ) were read from the recording. (3) Shape retention on toothbrush: sample inner diameter 3 m
It was filled in a container of m, and about 0.5 g was placed on the toothbrush, and the degree of dripping from the toothbrush when the toothbrush was tilted at about 90 ° was visually evaluated. A: Almost no change in shape. Δ: The shape changes slightly, but does not drip. X: The shape changes and sags. (4) Dispersibility: 20 ml of water was added to a test tube with a stopper containing 1 g of the sample, and the undissolved residue of the sample was visually evaluated when stirring for 10 seconds. ◯: No undissolved residue. Δ: Slightly left unmelted. X: Remaining unmelted is noticeable. (5) Feel of use: A dentifrice composition was used and evaluated by sensory evaluation. ◯: Well dispersed, no discomfort. Δ: Dispersed, but somewhat uncomfortable. X: Dispersibility is poor and there is a feeling of strangeness. (6) Effect of fluorine compound: Tooth slice (thickness 130μ
m) is immersed in deashing solution (pH 4.3) for 4 days, and CMR
(The amount of decalcification of the teeth was measured as the area of the recording paper by a device for performing X-ray photography and analyzing the image of the image. Toothpaste treatment was performed twice a day, and the toothpaste solution used for the treatment was 10 g of toothpaste. 20 g was added and dispersed for 30 seconds to obtain a supernatant.

From the results shown in Tables 1 and 2, xanthan gum, sodium polyacrylate was used as the binder, and a silica-based abrasive was used as the abrasive, and the ratio of the amount of the thickener to the amount of water was 1.5 or more. The composition was measured with a BH type viscometer. 2
5 The viscosity of 20rpm at ° C. is 100 to 250 poise, dentifrice compositions shear stress at a shear rate 64Min ^-1 at 25 ° C. as measured by Haake viscometer is not more than 2 times the shear stress at 8min ^-1 ( It was confirmed that Example) was excellent in shape retention and dispersibility and had a good feeling in use.

Further, in the dentifrice compositions of the examples, the effect of the fluorine compound is similar to that of the one having a low viscosity and a poor shape retention although the shape retention of the toothpaste is good. Was recognized.

[0031]

[Table 1]

[0032]

[Table 2]

─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-6-239721 (JP, A) JP-A-4-210908 (JP, A) JP-A-4-217614 (JP, A) JP-A-4- 217615 (JP, A) JP-A-8-175942 (JP, A) JP-A-6-157258 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) A61K 7/00-7 / 50

Claims (2)

(57) [Claims] 1. A silica-based abrasive, a binder comprising xanthan gum and sodium polyacrylate in combination, a thickener, and water, and the compounding ratio of water to the thickener is 1. The composition has a weight ratio of 1.5 to 2.2 and a viscosity of 20 rpm at 25 ° C. measured by a BH type viscometer of 100 to
Shear stress measured at 250 poise, double cylinder viscometer at 25 ° C at shear rate of 64 min ^-1 at shear stress of 8 m
A dentifrice composition having a shear stress of not more than twice the in- ¹ hour. 2. The dentifrice composition according to claim 1, further comprising a fluorine compound as an active ingredient.