TWI771148B - Preparation method of tricalcium silicate - Google Patents

Abstract

A preparation method of tricalcium silicate, comprising the following steps: mixing calcium nitrate hydrate, tetraethoxysilane, nitric acid aqueous solution and ethanol for condensation reaction to obtain a mixture; and calcining the mixture to obtain a mixture containing silicic acid The composition of tricalcium, wherein the molar ratio of the calcium nitrate hydrate and the tetraethoxysilane ranges from 3.0:1 to 3.5:1, the condensation reaction temperature is 80°C and the time range is 4 hours to 20 hours, the temperature of the calcination treatment was 1450°C and the time range was 1 hour to 5 hours. Through the mutual coordination of calcium nitrate hydrate, tetraethoxysilane, nitric acid aqueous solution and ethanol, and the design of the molar ratio of calcium nitrate hydrate and tetraethoxysilane, the preparation method of tricalcium silicate has high silicic acid Advantages of Tricalcium Yield.

Description

Preparation method of tricalcium silicate

The present invention relates to a preparation method of silicate, in particular to a preparation method of tricalcium silicate.

In general, endodontic treatment can be performed by root canal therapy, root apical filling, reverse apical filling and other surgeries, and in these surgeries, pulp filling materials are usually used to repair the damaged teeth after treatment. pulp tissue, so that the pulp tissue can be regenerated and restored. At present, the common dental pulp filling material is tricalcium silicate, and the preparation method of the tricalcium silicate uses water, calcium nitrate tetrahydrate, tetraethoxysilane and nitric acid aqueous solution as raw materials. However, although this method can obtain tricalcium silicate, it is easy to be accompanied by a large amount of dicalcium silicate, calcium oxide and calcium hydroxide, resulting in low yield of tricalcium silicate and low activity of dicalcium silicate. It is not easy to harden, so the presence of dicalcium silicate will cause the hardening time of the dental pulp filling material to become longer, and it is not suitable as a dental pulp filling material. In addition, calcium oxide and calcium hydroxide cannot form a stable matrix in the pulp tissue, and are easily washed away by the pulp tissue fluid to form a dead space in the pulp tissue, and calcium oxide and calcium hydroxide will burn the pulp tissue. The surface is not conducive to the regeneration of dental pulp tissue, so it is not suitable as a dental pulp filling material when there is a large amount of calcium oxide and calcium hydroxide.

Therefore, the purpose of the present invention is to provide a preparation method of tricalcium silicate with high tricalcium silicate yield.

Thus, the preparation method of tricalcium silicate of the present invention comprises the following steps: The calcium nitrate hydrate, tetraethoxysilane, nitric acid aqueous solution and ethanol are mixed for condensation reaction to obtain a mixture, wherein the molar ratio of the calcium nitrate hydrate and the tetraethoxysilane ranges from 3.0:1 to 3.5: 1, the nitric acid concentration of this nitric acid aqueous solution is 65wt%, the temperature of this condensation reaction is 80 ℃ and the time range is 4 hours to 20 hours; And The mixture is calcined to obtain a composition comprising tricalcium silicate, wherein the calcination temperature is 1450° C. and the time range is 1 hour to 5 hours.

The effect of the present invention lies in: through the mutual coordination of the calcium nitrate hydrate, the tetraethoxysilane, the nitric acid aqueous solution and the ethanol, and the design of the molar ratio of the calcium nitrate hydrate and the tetraethoxysilane, As a result, it is difficult to generate dicalcium silicate, calcium hydroxide and calcium oxide. Therefore, the preparation method of tricalcium silicate has the advantage of high tricalcium silicate yield.

The preparation method of tricalcium silicate of the present invention comprises the following steps: The calcium nitrate hydrate, tetraethoxysilane, nitric acid aqueous solution and ethanol are mixed for condensation reaction to obtain a mixture, wherein the molar ratio of the calcium nitrate hydrate and the tetraethoxysilane ranges from 3.0:1 to 3.5: 1, the nitric acid concentration of this nitric acid aqueous solution is 65wt%, the temperature of this condensation reaction is 80 ℃ and the time range is 4 hours to 20 hours; And The mixture is calcined to obtain a composition comprising tricalcium silicate, wherein the calcination temperature is 1450° C. and the time range is 1 hour to 5 hours.

<Calcium nitrate hydrate>

The calcium nitrate hydrate is, for example, but not limited to, calcium nitrate tetrahydrate. In some embodiments of the present invention, the calcium nitrate hydrate is calcium nitrate tetrahydrate.

<Ethanol>

In some embodiments of the present invention, the molar ratio of the ethanol to the tetraethoxysilane is 10.59:1.

<Nitric acid aqueous solution>

In some embodiments of the present invention, in order to make the preparation method of tricalcium silicate of the present invention have a lower generation amount of calcium oxide, based on the amount of the ethanol being 100 mL, the amount of the nitric acid is in the range of 2.2 g to 9.0 g g.

<Condensation reaction>

In some embodiments of the present invention, in order to ensure that the calcium nitrate hydrate and the tetraethoxysilane can react completely, so that the preparation method of tricalcium silicate of the present invention has a higher generation amount of tricalcium silicate And lower calcium oxide generation, the condensation reaction time range is 12 hours to 16 hours.

<Calcination treatment>

In some embodiments of the present invention, the preparation method of tricalcium silicate of the present invention is to control the time range of the calcination treatment to be 1 hour to 2 hours.

In the preparation method of tricalcium silicate of the present invention, the calcination treatment is performed by heating the mixture to 1450°C at a heating rate of 12°C/min.

The present invention will be further described with respect to the following examples, but it should be understood that the examples are only used for illustration and should not be construed as a limitation of the implementation of the present invention.

[Example 1]

5.9 g of calcium nitrate tetrahydrate, 1.87 mL of tetraethoxysilane (density of 0.933 g/mL), 0.125 mL of nitric acid aqueous solution containing 65wt% nitric acid (density of 1.38 g/mL) and 5 mL of ethanol ( The density is 0.816g/mL), and stirred for 1 hour to obtain a mixed solution, wherein, based on the amount of the ethanol being 100mL, the amount of the nitric acid is 2.24g. Next, the mixed solution was placed in an oven at 80° C. to carry out a condensation reaction for 4 hours to obtain a mixture. The mixture was placed in an alumina crucible, and the alumina crucible containing the mixture was placed in a high temperature furnace, and the mixture was heated to 1450°C at a heating rate of 12°C/min, and the mixture was heated at 1450°C. A calcination treatment was performed at ℃ for 2 hours to obtain a composition comprising tricalcium silicate and dicalcium silicate.

[Examples 2 to 13]

Examples 2 to 13 obtain compositions containing tricalcium silicate and dicalcium silicate in the same manner as in Example 1, except that the amount of each component is changed, and the conditions of condensation reaction and calcination treatment are changed, such as: shown in Table 1 to Table 2.

[Comparative Example 1]

Comparative Example 1 was carried out in a similar manner to Example 1, except that the ethanol of Example 1 was replaced with water.

[Comparative Examples 2 to 5]

Comparative Examples 2 to 5 were carried out in the same manner as in Example 1, except that the amount of each component was changed, and the conditions of condensation reaction and calcination treatment were changed, as shown in Table 3.

[Evaluation item]

X-ray diffraction analysis: An X-ray diffraction analyzer (manufacturer: Bruker; model: D2 Phaser) was used to analyze the composition of the compositions of Examples 1 to 13 and Comparative Examples 1 to 5, wherein the 2θ was 18.2 The characteristic peaks at °, 26.7°, 32.2° and 32.7° are calcium hydroxide, calcium oxide, tricalcium silicate and dicalcium silicate in sequence. The light source of this X-ray diffraction analyzer is CuKα (wavelength is 1.54184Å), the filter is Ni filter, the current is 10mA, the scanning angle is 10° to 80°, the scanning angle interval is 0.02°, and the interval scanning time is 0.5 seconds.

Table 1 Example 1 2 3 4 5 6 7 calcium nitrate tetrahydrate Dosage (g) 5.9 5.9 5.9 5.9 5.9 5.9 5.9 Moore 0.025 0.025 0.025 0.025 0.025 0.025 0.025 Tetraethoxysilane Dosage (mL) 1.87 1.87 1.87 1.87 1.87 1.87 1.87 Moore 0.008 0.008 0.008 0.008 0.008 0.008 0.008 Molar ratio of calcium nitrate tetrahydrate to tetraethoxysilane 3.0:1 3.0:1 3.0:1 3.0:1 3.0:1 3.0:1 3.0:1 Aqueous nitric acid Dosage (mL) 0.125 0.125 0.125 0.125 0.125 0.125 0.125 Dosage (g) 0.1725 0.1725 0.1725 0.1725 0.1725 0.1725 0.1725 Nitric acid content (g) 0.112 0.112 0.112 0.112 0.112 0.112 0.112 Ethanol Dosage (mL) 5 5 5 5 5 5 5 Moore 0.089 0.089 0.089 0.089 0.089 0.089 0.089 Molar ratio of ethanol to tetraethoxysilane 10.59:1 10.59:1 10.59:1 10.59:1 10.59:1 10.59:1 10.59:1 water Dosage (mL) 0 0 0 0 0 0 0 Moore 0 0 0 0 0 0 0 Stirring time (hr) 1 1 1 1 1 1 1 condensation reaction time (hr) 4 8 12 16 20 16 16 temperature(℃) 80 80 80 80 80 80 80 Calcining Heating rate (℃/min) 12 12 12 12 12 12 12 temperature(℃) 1450 1450 1450 1450 1450 1450 1450 time (hr) 2 2 2 2 2 1 3 Characteristic peak intensity of tricalcium silicate (2θ=32.2°, au) 2083 2363 2353 2602 2524 2419 2433 Characteristic peak intensity of dicalcium silicate (2θ=32.7°, au) 1623 1736 1787 1775 1703 1685 1854 Characteristic peak intensity of calcium hydroxide (2θ=18.2°, au) 304 505 334 198 367 106 137 Characteristic peak intensity of calcium oxide (2θ=26.7°, au) 82 129 130 89 190 115 102

Table 2 Example 8 9 10 11 12 13 calcium nitrate tetrahydrate Dosage (g) 5.9 5.9 6.9 6.9 6.9 6.9 Moore 0.025 0.025 0.029 0.029 0.029 0.029 Tetraethoxysilane Dosage (mL) 1.87 1.87 1.87 1.87 1.87 1.87 Moore 0.008 0.008 0.008 0.008 0.008 0.008 Molar ratio of calcium nitrate tetrahydrate to tetraethoxysilane 3.0:1 3.0:1 3.5:1 3.5:1 3.5:1 3.5:1 Aqueous nitric acid Dosage (mL) 0.125 0.125 0.125 0.25 0.375 0.5 Dosage (g) 0.1725 0.1725 0.1725 0.345 0.5175 0.69 Nitric acid content (g) 0.112 0.112 0.112 0.224 0.336 0.449 Ethanol Dosage (mL) 5 5 5 5 5 5 Moore 0.089 0.089 0.089 0.089 0.089 0.089 Molar ratio of ethanol to tetraethoxysilane 10.59:1 10.59:1 10.59:1 10.59:1 10.59:1 10.59:1 water Dosage (mL) 0 0 0 0 0 0 Moore 0 0 0 0 0 0 Stirring time (hr) 1 1 1 1 1 1 condensation reaction time (hr) 16 16 16 16 16 16 temperature(℃) 80 80 80 80 80 80 Calcining Heating rate (℃/min) 12 12 12 12 12 12 temperature(℃) 1450 1450 1450 1450 1450 1450 time (hr) 4 5 2 2 2 2 Characteristic peak intensity of tricalcium silicate (2θ=32.2°, au) 2330 2176 2385 3070 2596 2566 Characteristic peak intensity of dicalcium silicate (2θ=32.7°, au) 1765 1868 1442 1580 1771 1443 Characteristic peak intensity of calcium hydroxide (2θ=18.2°, au) 254 279 66 34 299 81 Characteristic peak intensity of calcium oxide (2θ=26.7°, au) 149 147 110 49 170 71

table 3 Comparative example 1 2 3 4 5 calcium nitrate tetrahydrate Dosage (g) 6.9 7.9 8.9 9.9 6.9 Moore 0.029 0.033 0.038 0.042 0.029 Tetraethoxysilane Dosage (mL) 1.87 1.87 1.87 1.87 1.87 Moore 0.008 0.008 0.008 0.008 0.008 Molar ratio of calcium nitrate tetrahydrate to tetraethoxysilane 3.5:1 4.0:1 4.5:1 5.0:1 3.5:1 Aqueous nitric acid Dosage (mL) 0.25 0.125 0.125 0.125 0 Dosage (g) 0.345 0.1725 0.1725 0.1725 0 Nitric acid content (g) 0.224 0.112 0.112 0.112 0 Ethanol Dosage (mL) 0 5 5 5 5 Moore 0 0.089 0.089 0.089 0.089 Molar ratio of ethanol to tetraethoxysilane 0 10.59:1 10.59:1 10.59:1 10.59:1 water Dosage (mL) 5 0 0 0 0 Moore 0.278 0 0 0 0 Stirring time (hr) 1 1 1 1 1 condensation reaction time (hr) 16 16 16 16 16 temperature(℃) 80 80 80 80 80 Calcining Heating rate (℃/min) 12 12 12 12 12 temperature(℃) 1450 1450 1450 1450 1450 time (hr) 2 2 2 2 2 Characteristic peak intensity of tricalcium silicate (2θ=32.2°, au) 549 1342 901 350 1082 Characteristic peak intensity of dicalcium silicate (2θ=32.7°, au) 1988 1447 1273 1321 874 Characteristic peak intensity of calcium hydroxide (2θ=18.2°, au) 2125 2228 1987 2875 27 Characteristic peak intensity of calcium oxide (2θ=26.7°, au) 256 204 126 181 646

Referring to Table 1, Table 2 and Figures 1 to 5, by using the calcium nitrate hydrate, the tetraethoxysilane, the aqueous nitric acid solution and the ethanol, and controlling the interaction between the calcium nitrate hydrate and the tetraethoxysilane Molar ratio, in Examples 1 to 13, the intensity of the characteristic peak (2θ=32.2°) of the tricalcium silicate is greater than the intensity of the characteristic peak (2θ=32.7°) of the dicalcium silicate, and relative to the The intensities of the characteristic peaks of tricalcium silicate, the characteristic peaks of calcium hydroxide whose 2θ is 18.2°, and the intensities of the characteristic peaks of calcium oxide whose 2θ is 26.7° are extremely low, indicating that the compositions of Examples 1 to 13 have high content of tricalcium silicate. It can be seen from the above that the preparation method of tricalcium silicate of the present invention can indeed make the dicalcium silicate, the calcium hydroxide and the calcium oxide difficult to generate, and has the advantage of high content of tricalcium silicate.

Referring to Tables 1 to 3, compared to Examples 1 to 13, which were carried out under ethanol conditions, in Comparative Example 1, only water without ethanol was used to prepare tricalcium silicate, resulting in the characteristic peak of dicalcium silicate. The intensity of the characteristic peaks of calcium hydroxide and tricalcium silicate is much larger than that of tricalcium silicate. It can be seen that there are a large amount of dicalcium silicate and calcium hydroxide in the way of preparing tricalcium silicate with water.

Referring to Tables 2 and 3, compared with Example 10, in Comparative Examples 2 to 4, the molar ratio of the calcium nitrate hydrate to the tetraethoxysilane was greater than 3.5:1, resulting in the dicalcium silicate The intensity of the characteristic peak of calcium hydroxide and the characteristic peak of calcium hydroxide is much greater than that of tricalcium silicate. It can be seen that the molar ratio range of the calcium nitrate hydrate and the tetraethoxysilane is greater than 3.5:1 The method designed to prepare tricalcium silicate will have a large amount of dicalcium silicate and calcium hydroxide, resulting in a low yield of the tricalcium silicate.

On the other hand, referring to Tables 2 to 3, compared to Examples 10 to 13, which were carried out in the presence of nitric acid, Comparative Example 5 did not use the nitric acid, and although the characteristics of the tricalcium silicate of Comparative Example 5 were The intensity of the peak is still greater than that of the characteristic peak of dicalcium silicate, but the intensity of the characteristic peak of calcium oxide when 2θ is 26.7° in the XRD pattern of the composition of Comparative Example 5 is relatively high, indicating that compared with Example 10 to In the composition of 13, the amount of calcium oxide produced in the composition of Comparative Example 5 was high. It can be seen from the above that there is a large amount of calcium oxide in the way of preparing tricalcium silicate without using nitric acid, resulting in a low yield of the tricalcium silicate.

To sum up, the preparation method of tricalcium silicate of the present invention is through the interaction of the calcium nitrate hydrate, the tetraethoxysilane, the nitric acid aqueous solution and the ethanol, and the calcium nitrate hydrate and the tetraethoxy The design of the molar ratio of silane makes it difficult to generate dicalcium silicate, calcium hydroxide and calcium oxide. Therefore, the preparation method of tricalcium silicate has the advantage of high tricalcium silicate yield, so the present invention can indeed be achieved. the goal of.

However, the above are only examples of the present invention, and should not limit the scope of implementation of the present invention. Any simple equivalent changes and modifications made according to the scope of the patent application of the present invention and the contents of the patent specification are still included in the scope of the present invention. within the scope of the invention patent.

Other features and effects of the present invention will be clearly presented in the embodiments with reference to the drawings, wherein: 1 is an XRD pattern illustrating the components of Examples 1 to 5 and Comparative Example 1; Figure 2 is an XRD pattern illustrating the components of Example 4, Examples 6 to 9 and Comparative Example 1; 3 is an XRD pattern illustrating the components of Example 4, Example 10 and Comparative Examples 1 to 4; Figure 4 is an XRD pattern illustrating the composition of Examples 10 to 13, Comparative Example 1 and Comparative Example 5; and FIG. 5 is an enlarged XRD pattern of FIG. 4 illustrating the composition of Example 11 and Comparative Example 1. FIG.

Claims (4)

A preparation method of tricalcium silicate, comprising the following steps: mixing calcium nitrate hydrate, tetraethoxysilane, aqueous nitric acid and ethanol for condensation reaction to obtain a mixture, wherein the calcium nitrate hydrate and the tetraethoxy The molar ratio of the silane is in the range of 3.0:1 to 3.5:1, the nitric acid concentration of the nitric acid aqueous solution is 65 wt %, the temperature of the condensation reaction is 80° C. and the time range is 4 hours to 20 hours; and the mixture is calcined treatment to obtain a composition comprising tricalcium silicate, wherein the temperature of the calcination treatment is 1450° C. and the time range is 1 hour to 5 hours. The preparation method of tricalcium silicate according to claim 1, wherein the calcium nitrate hydrate is calcium nitrate tetrahydrate. The preparation method of tricalcium silicate according to claim 1, further comprising heating the mixture to 1450°C at a heating rate of 12°C/min to perform the calcination treatment. The method for preparing tricalcium silicate according to claim 1, wherein, based on the amount of the ethanol being 100 mL, the amount of nitric acid in the aqueous nitric acid solution ranges from 2.2 g to 9.0 g.

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