JPH05362B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to an amorphous aluminosilicate base agent for tooth brushing. The dentifrice base is used as a dentifrice composition by being mixed with other ingredients such as foaming agents, wetting agents, binders, flavoring agents, and preservatives. The dentifrice base is usually the dentifrice base of the dentifrice composition.
It is an important component that accounts for 15 to 50% of teeth, and plays the role of polishing teeth without damaging them, removing food residue and plaque from the mouth, and giving teeth their natural shine. [Prior Art] As dentifrice bases, dibasic calcium phosphate, calcium carbonate, aluminum hydroxide, hydrated silicic acid, and the like have been known, and each has been put to practical use. Each of these has its own characteristics in its use. That is, dibasic calcium phosphate is the most excellent in terms of polishing power and cleaning power, which are important functions of a toothpaste base, and is currently used in the largest amount. Although calcium carbonate is inferior to dibasic calcium phosphate in terms of polishing power and cleaning power, it is inexpensive and is used in some dentifrice compositions due to its economic advantages. Aluminum hydroxide is intermediate between dibasic calcium phosphate and calcium carbonate in terms of price, polishing power, and cleaning power. On the other hand, the purpose of use of hydrated silicic acid is different from that of the above-mentioned base material. That is, it is used for transparent dentifrice compositions. However, it is very expensive and its polishing power and cleaning power are inferior to dibasic calcium phosphate, so its usage is small. As mentioned above, each base is used depending on its purpose. Incidentally, in recent years, it has been desired to incorporate medicinal ingredients, mainly fluorine compounds, into dentifrice compositions from the viewpoint of preventing cavities or tartar. However, conventional dicalcium phosphate has the disadvantage that it easily reacts with fluorine compounds and inhibits its function as a medicinal ingredient. Calcium carbonate and aluminum hydroxide similarly tend to react with medicinal ingredients.
Hydrous silicic acid has almost no reactivity with medicinal ingredients and is expected to be used as a base for dentifrice compositions containing medicinal ingredients, but as mentioned above, it has the disadvantages of being expensive and having insufficient polishing and cleaning power. have. It has been proposed to use amorphous aluminosilicate as a dentifrice base for the various dentifrice bases that have been conventionally used. For example, Tokkosho
No. 57-45411 discloses the use of a synthetic amorphous composite aluminosilicate having a refractive index of 1.44 to 1.47. This report states that amorphous aluminosilicate can be combined with medicinal ingredients that have a protective effect against dental caries, but its main purpose is as a base for transparent dentifrice compositions. According to the examples, the alumina content is at most 8% by weight.
(SiO ₂ /Al ₂ O ₃ molar ratio 15), and the polishing power and cleaning power are comparable to those of hydrous silicic acid. As described above, a dentifrice base that has abrasive power and cleaning power equal to or higher than dibasic calcium phosphate and does not react with medicinal ingredients has not yet been obtained. [Problems to be Solved by the Invention] The object of the present invention is to provide a new dentifrice base that has polishing and cleaning powers equivalent to dicalcium phosphate and has low reactivity with medicinal ingredients, especially fluorine compounds. It is about providing. [Means for Solving the Problems] The gist of the present invention is that the chemical composition has the general formula M ₂ /mO・Al ₂ O ₃・xSiO ₂・nH ₂ O, where M: an alkali metal or an alkaline earth metal m: Amorphous aluminosilicate represented by valence of metal M x: 2 to 20 n: 0 or a positive number, with an average particle size of 10 to 40 μ and a specific surface area of 50 to 130 m ² /g,
It is an amorphous aluminosilicate suitable as a dentifrice base having a static bulk density of 0.2 to 0.8 g/ml, and its details will be explained below. Aluminosilicate is generally based on Al ₂ O ₃ M ₂ /mO・Al ₂ O ₃・ySiO ₂・nH ₂ O where M: alkali metal or alkaline earth metal m: valence of metal M x: 2 ~∞ n: Represented by 0 or a positive number, consisting of a mutual bond between silica and alumina represented by a Si-O-Al bond, and the negative charge generated due to the difference in valence between Si and Al is transferred to an alkali metal or alkaline earth. Balanced with cations such as similar metals. Inorganic oxides with such compositions are either crystalline or amorphous, and zeolites have been known for a long time as crystalline substances, and are widely used as catalysts and adsorption/separation agents. However, its use as a toothpaste base has also been proposed. For example, Tokukai Akira
No. 57-54112 discloses the use of zeolite with an average particle size of 1 μm or less. Zeolite has higher hardness than dicalcium phosphate and has a high abrasive force on teeth. Therefore, particles with small particle size must be used so as not to damage the dentin of the tooth. In dentifrice bases, the particle size greatly affects the polishing power and cleaning power, but is also an important factor in actual use. That is, microparticles with a particle diameter of less than 10 μ tend to adhere to the teeth and the inside of the mouth, are not easily removed by normal rinsing, and tend to remain in the mouth. On the other hand, large particles exceeding 40μ give a rough feeling when brushing the teeth and tend to damage the dentin of the teeth. Therefore, it is desirable that the dentifrice base has an average particle diameter of 10 to 40 microns and has the desired polishing and cleaning power. For these reasons, although it is acceptable to use a small amount of crystalline aluminosilicate as an additive, there are problems with its use as a dentifrice base. On the other hand, the use of amorphous aluminosilicate as a dentifrice base has not yet been fully investigated, and as mentioned above, it has only been proposed for use in transparent dentifrice compositions. No one has been obtained that has sufficient power and cleaning power. As a result of various studies on aluminosilicate, the present inventors have found that an amorphous aluminosilicate having a composition and physical property values within a specific range has polishing power and cleaning power equivalent to dicalcium phosphate, and has a soft The present invention was completed by discovering that the reactivity with elementary compounds is low. The present invention has a desirable average particle size as a dentifrice base.
Regarding amorphous aluminosilicate with good fluorine stability, which has low reactivity with fluorine compounds within the range of 10 to 40 μ, the chemical composition is M ₂ /mO・Al ₂
It is expressed as O ₃・xSiO ₂・nH ₂ O, where x is within the composition range of 2 to 20, and the specific surface area and static bulk density are respectively
It is an amorphous aluminosilicate with strictly controlled physical properties within the range of 50 to 130 m ² /g and 0.2 to 0.8 g/ml, and has the same polishing and cleaning power as dicalcium phosphate, and It has good elementary stability. Each specified value will be explained below. It is necessary that x, which represents the composition, be in the range of 2 to 20. As mentioned above, aluminosilicate is Si-O
-Al bond, and in principle, the lower limit of x is 2. If x is less than 2, aluminum hydroxide will be mixed in, and the polishing power will decrease. Conversely, when x exceeds 20, the physical properties approach those of hydrated silicic acid and the polishing power decreases. Next, the specific surface area must be between 50 and 130 m ² /g. Even if x is within the range of 2 to 20, the desired effect cannot be obtained if the specific surface area is outside this range. It is generally said that the specific surface area is inversely proportional to the size of the primary particles. Therefore, as the specific surface area decreases, the polishing force tends to increase, and when the specific surface area is less than 50 m ² /g, the polishing force is strong enough to damage the dentin of the tooth. Conversely, 130m ² /
If it exceeds g, both polishing power and cleaning power will be insufficient. Static bulk density depends to some extent on physical properties such as particle size and specific surface area, but in order to achieve desirable polishing and cleaning power with an average particle size of 10 to 40μ, the composition and specific surface area must be within the above range. At the same time, the static bulk density is 0.2~
It is necessary to adjust the concentration to 0.8 g/ml. As mentioned above, static bulk density is correlated with particle size, specific surface area, etc., but it is also related to secondary particle structure, cohesive force, etc., and the mechanism of action on toothbrushing properties is complex. As a result of various studies on aluminosilicate, the present inventors discovered that there is a correlation between static bulk density and cleaning power. In other words, even if the composition and specific surface area are set within the above range, the static bulk density is
If it is less than 0.2 g/ml or more than 0.8 g/ml, the cleaning power will be significantly reduced, whereas if it is in the range of 0.2 to 0.8 g/ml, it will show the same performance as dibasic calcium phosphate. As mentioned above, the relationship between the composition and physical property values specified in the present invention and dentifrice properties such as polishing power and cleaning power is not necessarily clear, but when the composition and physical property values specified in the present invention are outside the range , the expected effect cannot be achieved. There are various methods for producing the amorphous aluminosilicate having the specific physical properties of the present invention, and there are no particular limitations. That is, an aqueous solution of an alkali silicate such as sodium silicate, potassium silicate, or lithium silicate and an aqueous solution of an aluminum salt such as aluminum sulfate, aluminum chloride, or aluminum nitrate, or an aqueous solution of an aluminate such as sodium aluminate are continuously or Mix batchwise to precipitate amorphous aluminosilicate particles. At this time, if necessary, mineral acids such as hydrochloric acid, sulfuric acid, and nitric acid, or alkalis such as sodium hydroxide, potassium hydroxide, and lithium hydroxide may be added. However, in order to obtain the desired physical property values for each component system, care must be taken as conditions such as reaction temperature, pH, and reaction time are different; however, by appropriately controlling these conditions, specific surface area, static bulk, etc. Density and particle size can be easily controlled. The resulting amorphous aluminosilicate slurry is heated if necessary, filtered and washed with water to remove water-soluble salts, and then dried by a conventional method. For example, oven drying, band drying, rotary kiln drying, etc. can be employed. The amorphous aluminosilicate of the present invention can be produced by any of the methods described above, but ultimately has the composition, specific surface area, static bulk density, and average particle size specified above. It is necessary. [Example] Next, the present invention will be explained in more detail with reference to Examples. Example 1 0.83 kg of caustic soda and 8.5 kg of pure water were added and mixed to 6.8 kg of No. 3 sodium silicate having a SiO ₂ concentration of 29.0 wt% to prepare a diluted sodium silicate aqueous solution. 16.1 kg of the diluted sodium silicate aqueous solution and Al ₂ O ₃ concentration 8.0 wt were placed in a 2.4 L reaction tank equipped with a stirrer and overflow.
% aluminum sulfate aqueous solution 6.5Kg/180ml each
min, continuous addition and mixing at a speed of 60ml/min,
The reaction was carried out at 40°C to precipitate amorphous aluminosilicate. The resulting slurry was filtered and washed with water, and then dried with hot air at 110°C. The obtained amorphous aluminum silicate had the composition and physical properties shown in Table 1. Next, the dentifrice properties of amorphous aluminosilicate are second to none.
As shown in the table, it had the same polishing and cleaning power as dibasic calcium phosphate, and had good fluorine stability, making it suitable as a toothpaste base. The physical property values and tooth brushing property values of the amorphous aluminosilicate were determined as follows. 1 Average particle size Measured using a Microtrac particle size analyzer (Leed & Northrup) using the laser method. 2 Specific surface area Measured using Autopore 9200 (manufactured by Shimadzu Corporation) by mercury intrusion method. 3. Static bulk density Measured using Seishin's static tap density KYT-2000. 4 Polishing power Using a suspension consisting of 15 g of a sample (amorphous aluminosilicate) suspended in 70 g of a 60% glycerin aqueous solution containing 0.4% CMC and 0.7% propylene glycol, a silver plate was held horizontally under a load of 240 g. The silver plate was brushed 3000 times in one hour using a mold polishing tester, and the amount of wear on the silver plate was measured. 5. Cleaning power Collect tobacco tar in the usual way, apply it evenly on the tile as a solution with ethyl alcohol, heat and dry it, set it in a polisher, and measure it in the same way as the polishing power measurement method. 5g of sample (amorphous aluminosilicate) 46% containing 1% CMC
Brushing was performed 300 times under a load of 240 g using a suspension made by suspending 15 g of a glycerin aqueous solution, and the removal rate of tobacco tar from the tiles after polishing was visually evaluated. The evaluation criteria are as follows. Evaluation criteria Score 1: Smoke tar removal rate 0-10% 2: 11-20% 3: 21-30% 4: 31-40% 5: 41-50% 6: 51-60% 7: Smoke tar removal rate 61-70% 8: 〃 71-80% 9: 〃 81-90% 10: 〃 81-100% 6 Fluorine stability NaF was dissolved in ion-exchanged water and the fluorine ion concentration was 1000 ppm. Prepare standard solution. The base liquid 60
ml of sample (amorphous aluminosilicate), stirred for 10 minutes, and then left to stand in a thermostat at 50°C for 2 days. After being removed from the thermostatic bath, stirred for 10 minutes after cooling, solid-liquid separation is performed using a centrifuge, and the concentration of fluorine ions remaining in the liquid phase is measured with a potentiometer using a fluorine ion electrode. Example 2 6.14Kg of No. 3 sodium silicate with SiO ₂ concentration of 29.0wt%,
A diluted sodium silicate aqueous solution was prepared by mixing 7.7 kg of pure water. Further, 2.53 kg of aluminum sulfate aqueous solution having an Al ₂ O ₃ concentration of 8.0 wt%, 0.13 kg of 98 wt% concentrated sulfuric acid, and 1.12 kg of pure water were mixed to prepare a diluted aluminum sulfate aqueous solution. 13.9 kg of the diluted sodium silicate aqueous solution and the diluted aluminum sulfate aqueous solution were placed in a 15 L reaction tank equipped with a stirrer and overflow.
The mixture was added and mixed semi-batchwise at a rate of 160 ml/min and 40 ml/min, and reacted at pH 7 and 60°C to precipitate amorphous aluminosilicate. Thereafter, an amorphous aluminosilicate was obtained in the same manner as in Example 1, and the composition, physical property values, and dentifrice property values were measured. The composition and physical property values are shown in Table 1, and the toothbrushing property values are shown in Table 2.
Shown in the table. As is clear from each table, the amorphous aluminosilicate according to the present invention is suitable as a dentifrice base. Comparative example 1 No. 3 sodium silicate 6.14Kg with SiO ₂ concentration 29.Owt%
and 7.7 kg of pure water were mixed to prepare a diluted sodium silicate aqueous solution. In addition, 1.51 kg of aluminum sulfate aqueous solution with Al ₂ O ₃ concentration of 8.0 wt%, 0.45 kg of 98 wt% concentrated sulfuric acid
Kg and 1.67 Kg of pure water were mixed to prepare a diluted aluminum sulfate aqueous solution. The diluted sodium silicate aqueous solution and the diluted aluminum sulfate aqueous solution were added to the reaction tank used in Example 1 at 240 ml/min and 60 ml/min, respectively.
Add and mix continuously at a rate of , react at 60℃,
An amorphous aluminosilicate with a SiO ₂ /Al ₂ O ₃ molar ratio of 25 was obtained. The physical property values and dentifrice characteristic values are shown in Tables 1 and 2, respectively. Comparative Example 2 In the same manner as in Example 1, except that the mixed liquid
The reaction was carried out while adjusting the addition rate of the aluminum sulfate aqueous solution so that the pH was 5 or less. The physical property values and tooth brushing property values of the obtained amorphous aluminosilicate are shown in Tables 1 and 2, respectively. Comparative Example 3 In the same manner as in Example 1, except that the mixed liquid
The reaction was carried out while adjusting the addition rate of the diluted sodium silicate aqueous solution so that the pH was 9. The physical property values and tooth brushing property values of the obtained amorphous aluminosilicate are shown in Tables 1 and 2, respectively. Comparative Example 4 The same method as in Example 1 was carried out, except that the addition rates of the diluted sodium silicate aqueous solution and the aluminum sulfate aqueous solution were 540 ml/min and 180 ml/min, respectively. The physical property values and tooth brushing property values of the obtained amorphous aluminosilicate are shown in Tables 1 and 2, respectively. Comparative Example 5 The same method as in Example 1 was carried out, except that the addition rates of the diluted sodium silicate aqueous solution and the aluminum sulfate aqueous solution were 18 ml/min and 6 ml/min, respectively. The physical property values and tooth brushing property values of the obtained amorphous aluminosilicate are shown in Tables 1 and 2, respectively.

【table】

【table】

[Table] Characteristic values are shown.
[Effects of the Invention] As is clear from the above explanation, the amorphous aluminosilicate according to the present invention has abrasive power and cleaning power equivalent to dicalcium phosphate, and is a dentifrice base that can be blended with medicinal ingredients. It is a base material with suitable properties as a chemical agent.

Claims (1)

[Claims] 1. Chemical composition is the general formula M ₂ /mO・Al ₂ O ₃・xSiO ₂・nH ₂ O, where M: alkali metal or alkaline earth metal m: valence of metal M x: 2~ 20 n: Amorphous aluminosilicate expressed by 0 or a positive number, with an average particle size of 10 to 40 μ and a specific surface area of 50 to 130 m ² /g,
An amorphous aluminosilicate base agent for toothpaste having a static bulk density of 0.2 to 0.8 g/ml.