KR20200081733A - A needle crystalline lithium disilicate glass-ceramics having excellent stain resistance and a method for manufacturing the same - Google Patents

Abstract

One embodiment of the present invention provides crystallization glass and a manufacturing method thereof, in which the crystallization glass includes: an oxide represented by the following formula, A_xO_y, where A denotes at least one selected from the group consisting of Si, Li, P, Al, B, and Zr, and each of x and y denotes one of integers from 1 to 5, which satisfies the formula; a rare earth oxide; and a colorant, wherein a content of the rare earth oxide in the crystallization glass is 1 to 15 wt%, and the rare earth oxide is crystallized on a surface of the crystallization glass to have hydrophobicity.

Description

Crystallized glass with excellent stain resistance and its manufacturing method{A NEEDLE CRYSTALLINE LITHIUM DISILICATE GLASS-CERAMICS HAVING EXCELLENT STAIN RESISTANCE AND A METHOD FOR MANUFACTURING THE SAME}

The present invention relates to a crystallized glass having excellent stain resistance and a method for manufacturing the same.

If a tooth is lost due to caries or fracture damage or defect, a large obstacle to pronunciation, authoring, and aesthetics occurs. In addition, when adjacent teeth move to an empty space without teeth, when the normal arrangement of teeth starts to deviate, food gets stuck between the teeth, causing cavities or odors, and a bad smell. In particular, the damage or deficiency of the molars may cause malnutrition because they cannot eat properly. In addition, the damage or defect of the front teeth not only causes an aesthetic problem, but also increases the probability that secondary caries will occur in the damaged or damaged area.

Accordingly, many types of dental prosthetic restorations have been introduced, and among them, various non-metal materials that do not use metal have been developed. These dental restorative materials have been used in a wide range, such as dental fractures and aesthetic dental treatments caused by caries or fractures of teeth.

Among these dental restorative materials, ceramic materials have excellent advantages such as compressive strength, abrasion resistance, aesthetics, and chemical stability, but are brittle, so they are weak to tensile and impact, and have large plastic shrinkage, resulting in poor marginal suitability of the restoration. In order to compensate for this, a heat-pressing technique, which is crystallized in a glass state and then molded at a high temperature, is used. This thermoforming method exhibits advantages in that the manufacturing process is accurate, the porosity is low, and the strength is high compared to the conventional sintering method. However, as a lot of energy is used through the step of growing the glass crystal through a heat treatment process of 800° C. or higher, a more efficient method is required.

In addition, when these dental restorative materials are applied to teeth, they are exposed to contamination by various foods, but despite the need for a technique to prevent them, no technology has been proposed to impart contamination resistance to dental restorative materials to date. .

The present invention is to solve the above-mentioned problems of the prior art, the object of the present invention is to provide a crystallized glass having excellent stain resistance and a method for manufacturing the same.

In one aspect of the present invention, in a crystallized glass comprising an oxide, a rare earth oxide, and a colorant represented by the following formula, the content of the rare earth oxide in the crystallized glass is 1 to 15% by weight, and the rare earth oxide is the crystallized glass Crystallized on the surface of to provide a crystallized glass having hydrophobicity.

<expression>

A _x O _y

In the above formula, A is at least one selected from the group consisting of Si, Li, P, Al, B and Zr, and x and y are each one of integers from 1 to 5 satisfying the above formula.

In one embodiment, the oxide is SiO ₂ 65.0 ~ 75.0 wt%, Li ₂ O 10.0 ~ 15.0 wt%, P ₂ O ₅ 3.0 ~ 5.0 wt%, Al ₂ O ₃ 1.0 ~ 5.0 wt%, B ₂ O ₃ 3.0 to 6.0% by weight, and ZrO ₂ 0.01 to 3.0% by weight.

In one embodiment, the rare earth oxide is cerium (Ce), dysprosium (Dy), erbium (Er), europium (Eu), gadolinium (Gd), holmium (Ho), lanthanum (La), lutetium (Lu) , Neodymium (Nd), Praseodymium (Pr), Promethium (Pm), Samarium (Sm), Scandium (Sc), Terbium (Tb), Thulium (Tm), Ytterbium (Yb), Yttrium (Y) and 2 of them It may be one oxide selected from the group consisting of the above combination.

In one embodiment, the content of the colorant in the crystallized glass may be 1 to 6% by weight.

In one embodiment, the colorant may be one selected from the group consisting of TiO ₂ , Fe ₂ O ₃ , V ₂ O ₅ , V ₂ O ₃ , TaO ₂ , MnO ₂ and combinations of two or more of them.

In one embodiment, the contact angle of the surface of the crystallized glass with water may be 60° or more.

Another aspect of the present invention, a) preparing an oxide, a rare earth oxide and a mixture comprising a colorant represented by the following formula; b) heat-treating the mixture at 450-550° C. for 1-2 hours to form a nucleus; And c) step of growing the crystal by heat treatment for 1 to 2 hours at 600 ~ 800 ℃; provides a method for producing a crystallized glass comprising a.

<expression>

A _x O _y

In the above formula, A is at least one selected from the group consisting of Si, Li, P, Al, B and Zr, and x and y are each one of integers from 1 to 5 satisfying the above formula.

In one embodiment, the oxide is SiO ₂ 65.0 ~ 75.0 wt%, Li ₂ O 10.0 ~ 15.0 wt%, P ₂ O ₅ 3.0 ~ 5.0 wt%, Al ₂ O ₃ 1.0 ~ 5.0 wt%, B ₂ O ₃ 3.0 to 6.0% by weight, and ZrO ₂ 0.01 to 3.0% by weight.

In one embodiment, the rare earth oxide is cerium (Ce), dysprosium (Dy), erbium (Er), europium (Eu), gadolinium (Gd), holmium (Ho), lanthanum (La), lutetium (Lu) , Neodymium (Nd), Praseodymium (Pr), Promethium (Pm), Samarium (Sm), Scandium (Sc), Terbium (Tb), Thulium (Tm), Ytterbium (Yb), Yttrium (Y) and 2 of them It may be one oxide selected from the group consisting of the above combination.

In one embodiment, the content of the colorant in the mixture may be 1 to 6% by weight.

In one embodiment, the colorant may be one selected from the group consisting of TiO ₂ , Fe ₂ O ₃ , V ₂ O ₅ , V ₂ O ₃ , TaO ₂ , MnO ₂ and combinations of two or more of them.

In the crystallized glass according to an aspect of the present invention, a certain amount of rare earth oxide is crystallized on the surface to have hydrophobicity, thereby imparting hydrophobicity to the surface of the crystallized glass, whereby the crystallized glass is contaminated by food after being applied to the teeth. Can be effectively prevented.

It should be understood that the effects of the present invention are not limited to the above-described effects, and include all effects that can be deduced from the configuration of the invention described in the detailed description or claims of the present invention.

1 is an XRD (X-ray diffraction) analysis results before and after the second heat treatment for the crystallized glass according to an embodiment of the present invention;
2 is a scanning electron microscopy (SEM)/energy dispersive X-ray spectrometry (EDS) analysis result of crystallized glass according to an embodiment of the present invention;
3 is a result of measuring the contact angle of water in a crystallized glass according to Examples and Comparative Examples of the present invention;
4 and 5 are anti-fouling property evaluation results using a colormetric spectrophotometer (CM-3500D) of crystallized glass according to Examples and Comparative Examples of the present invention.
6 is a schematic diagram of the hydrophobic expression mechanism of rare earth oxide according to an embodiment of the present invention.
7 is a result of the evaluation of contamination resistance according to Examples and Comparative Examples of the present invention.

Hereinafter, the present invention will be described with reference to the accompanying drawings. However, the present invention may be implemented in various different forms, and thus is not limited to the embodiments described herein. In addition, in order to clearly describe the present invention in the drawings, parts irrelevant to the description are omitted, and like reference numerals are assigned to similar parts throughout the specification.

Throughout the specification, when a part is "connected" to another part, this includes not only "directly connected" but also "indirectly connected" with another member in between. . Also, when a part “includes” a certain component, this means that other components may be further provided instead of excluding other components, unless specifically stated otherwise.

In one aspect of the present invention, in a crystallized glass comprising an oxide, a rare earth oxide, and a colorant represented by the following formula, the content of the rare earth oxide in the crystallized glass is 1 to 15% by weight, and the rare earth oxide is the crystallized glass A crystallized glass having a hydrophobicity, preferably crystallized on the surface of a lithium disilicate crystallized glass.

<expression>

A _x O _y

In the above formula, A is at least one selected from the group consisting of Si, Li, P, Al, B and Zr, and x and y are each one of integers from 1 to 5 satisfying the above formula.

As used herein, the term "lithium disilicate (Lithium disilicate) crystallized glass" may be made of lithium disilicate-based glass-ceramics (lithium disilicate-based glass ceramics), Li ₂ O-Al ₂ O ₃ -SiO Using a glass such as ₂ -K ₂ OB ₂ O ₃ -P ₂ O ₅ , the crystal phase and strength may be different depending on the heat treatment conditions for crystal nucleation and growth.

The oxide is SiO ₂ 65.0 ~ 75.0 wt%, Li ₂ O 10.0 ~ 15.0 wt%, P ₂ O ₅ 3.0 ~ 5.0 wt%, Al ₂ O ₃ 1.0 ~ 5.0 wt%, B ₂ O ₃ 3.0 ~ 6.0 wt%, And ZrO ₂ 0.01 to 3.0% by weight.

SiO ₂ and Li ₂ O act as a main component of lithium disilicate crystal formation, P ₂ O ₅ acts as a nucleating agent, and Al ₂ O ₃ enhances the durability of crystallized glass. In addition, B ₂ O ₃ lowers the formation temperature of lithium disilicate crystals and reduces the size of crystals, and ZrO ₂ enhances the strength and chemical durability of crystals. In addition, alkali oxide increases meltability upon melting for glass formation, and ZnO lowers the production temperature of lithium disilicate crystals and enhances the chemical durability of the crystals. The colorant enhances the degree of harmony with the teeth and imparts aesthetic sense.

The rare earth oxide crystallizes on the surface of the crystallized glass to have hydrophobicity, thereby imparting hydrophobicity to the surface of the crystallized glass, thereby effectively preventing the crystallized glass from being contaminated by food after being applied to the teeth.

6(b) is a schematic diagram of a hydrophobic expression mechanism of rare earth oxide (CeO ₂ ) according to an embodiment of the present invention. Referring to FIG. 6(b), the Ce atom has very low reactivity since 4f and 5s ² p ⁶ are not filled by electron pair repulsion. When CeO ₂ is in contact with water, the water molecules adjacent to CeO ₂ cannot form hydrogen bonds with non-polar rare earth atoms, and -OH in the water molecule is only one hydrogen bond with O in CeO ₂ . The surface of the rare earth oxide has a very low affinity for water, that is, it can be hydrophobic. On the other hand, referring to FIG. 6(a), when the crystallized glass does not contain rare earth oxide (CeO ₂ ), there are many polarized portions on the surface of the crystallized glass, and the water is caused by attraction between polar molecules having partial charge. The affinity for it becomes very high.

The rare earth oxide is cerium (Ce), dysprosium (Dy), erbium (Er), europium (Eu), gadolinium (Gd), holmium (Ho), lanthanum (La), ruthenium (Lu), neodymium (Nd), Praseodymium (Pr), Promethium (Pm), Samarium (Sm), Scandium (Sc), Terbium (Tb), Thulium (Tm), Ytterbium (Yb), Yttrium (Y), and combinations of two or more of these. One selected, preferably, may be an oxide of cerium (Ce), but is not limited thereto.

Natural teeth show a variety of fluorescence when exposed to ultraviolet light in the oral cavity, which differs from person to person, but has a bluish-white to yellowish-white color. The fluorescence of the natural teeth varies depending on the length and area of the teeth, and in order to increase the aesthetics of the dental restoration or prosthesis, it is necessary to make the color equivalent to the characteristics of the natural teeth.

As used herein, the term “coloring agent” is for imparting the same or similar color and fluorescence to teeth, and may be used by selecting or combining materials exhibiting white, yellow, black, and the like. The material that can be used as a colorant is not limited by the above, and any material capable of exhibiting color and fluorescence similar to natural teeth may be included without limitation, for example, TiO ₂ , Fe ₂ O ₃ , V ₂ O ₅ , V ₂ O ₃ , TaO ₂ , MnO ₂ and a combination of two or more of them. In addition, the content of the colorant in the crystallized glass may be 1 to 6% by weight.

The contact angle of the surface of the crystallized glass with respect to water may be 60° or more, preferably 80° or more, and in this case, hydrophobicity necessary to prevent contamination by food may be realized.

Another aspect of the present invention, a) preparing an oxide, a rare earth oxide and a mixture comprising a colorant represented by the following formula; b) heat-treating the mixture at 450-550° C. for 1-2 hours to form a nucleus; And c) step of growing the crystal by heat treatment for 1 to 2 hours at 600 ~ 800 ℃; provides a method for producing a crystallized glass comprising a.

<expression>

A _x O _y

In the above formula, A is at least one selected from the group consisting of Si, Li, P, Al, B and Zr, and x and y are each one of integers from 1 to 5 satisfying the above formula.

In step a), a mixture comprising the oxide represented by the above formula, a rare earth oxide, and a colorant may be prepared, and the types, contents, and effect of each component are the same as described above.

In steps b) and c), the mixture is heat-treated at 450-550°C for 1-2 hours (primary heat treatment) to form nuclei, and then heat-treated at 600-800°C for 1-2 hours (2 Secondary heat treatment) crystals can be grown.

Through the primary heat treatment, lithium metasilicate (lithium metasilicate) can be produced an intermediate phase (intermediate phase), and by performing a secondary heat treatment at a high temperature of 800 ℃ or more lithium metasilicate having a low chemical durability, the solid lithium disilicate crystallized glass Can be obtained. In addition, by the secondary heat treatment, the rare earth oxide mixed in step a) may crystallize on the surface of the crystallized glass to form a secondary phase, and the crystallized rare earth oxide prevents contamination by food. It can provide the required level of hydrophobicity.

Hereinafter, embodiments of the present invention will be described in detail.

Examples and comparative examples

SiO ₂ , Li ₂ O, P ₂ O ₅ , Al ₂ O ₃ , B ₂ O ₃ , ZrO ₂ , rare earth oxide (CeO ₂ ) and colorant (TbO ₂ ) are listed in Table 1 below as raw materials for manufacturing glass. The mixture was mixed according to the weight ratio (weight included in 100 g of glass crystals), and the mixed raw materials were subjected to primary heat treatment at 450 to 550°C for 1 to 2 hours to form a core of lithium disilicate crystallized glass. Thereafter, crystals were grown by secondary heat treatment at 800° C. for 2 hours each.

ingredient Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 SiO ₂ 70 69 65 72 62 64 Li ₂ O 12.5 10.5 10 12.5 10 10 P ₂ O ₅ 4.5 4.5 4 4.5 4.5 3 Al ₂ O ₃ 4 2 One 4 2 One B ₂ O ₃ 6 5 3 4.5 3.5 3 ZrO ₂ One One One One One 0.5 CeO ₂ One 7 15 0.5 16 17.5 TbO ₂ One One One One One One Sum 100 100 100 100 100 100

Experimental Example 1

1 is a result of X-ray diffraction (XRD) analysis before and after the second heat treatment for the crystallized glass according to Example 2, and FIG. 2 is a scanning electron microscopy (SEM)/EDS (energy dispersive) of the crystallized glass according to Example 2 X-ray spectrometry).

Referring to FIG. 1, almost no peak corresponding to CeO ₂ was observed on the surface of the crystallized glass before the second heat treatment, whereas a peak corresponding to CeO ₂ was strongly observed on the surface of the crystallized glass after the second heat treatment, when mixing. It can be seen that CeO ₂ , a rare earth oxide, was effectively crystallized on the surface by secondary heat treatment.

In addition, looking at the results of qualitative and quantitative analysis on the surface of the crystallized glass after the second heat treatment through FIG. 2, the content of the Ce element in the surface is about 42.56% by weight, and CeO ₂ used when mixing becomes a crystal phase on the surface of the glass. It can be seen that it has been expressed.

Experimental Example 2

Hydrophobic properties of the crystallized glass were evaluated by measuring the contact angle of secondary distilled water droplets on the surface of the plate-shaped specimen of the prepared lithium disilicate crystallized glass, and the results are shown in Tables 2 and 3 below.

ingredient Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Contact angle (°) 61.8 80.4 89.1 13.7 88.5 86.2

Referring to Tables 2 and 3, the contact angle with respect to secondary distilled water on the surface of the specimens prepared in Examples 1 to 3 is measured to be at least about 60°, preferably at least about 80°, so that the surface of the crystallized glass is On the other hand, in the case of the specimen of Comparative Example 1, the contact angle was about 13.7°, and the surface of the crystallized glass exhibited hydrophilicity. On the other hand, in the case of Comparative Examples 2 and 3 in which an excessive amount of rare earth oxide was used, the surface of the crystallized glass exhibits hydrophobicity, but it is expected that the coloring resistance decreases while the content of SiO ₂ decreases relatively.

Experimental Example 3

4 and 5 are anti-fouling property evaluation results using a colormetric spectrophotometer (CM-3500D) of crystallized glass according to Examples and Comparative Examples of the present invention. Specimens of the lithium disilicate crystallized glass prepared for observation were immersed in a colorant (black tea 1 bag/250 ml of black tea) for 4 weeks at 37°C, and the color change before and after immersion was measured using a colormetric spectrophotometer (CM-3500D). Was evaluated.

4 and 5, in the case of the crystallized glass of Examples 1 to 3, dE (Δ value is 5.0 or more after 4 weeks elapsed, and whitening retention ratio calculated based on dE (Δ value immediately before immersion) is 70%. On the other hand, the crystallized glass of Comparative Examples 1 to 3 had dE (Δ value rapidly lowered to less than 5.0) after 4 weeks, and thus the whitening retention ratio was also lowered to 60% or less. In the case of Comparative Examples 2 and 3, in which the content of SiO ₂ was relatively decreased as used, the antifouling property of the surface, that is, the coloring resistance was significantly lowered as expected.

Experimental Example 4

7 is a result of the evaluation of contamination resistance according to the Examples and Comparative Examples of the present invention. Specifically, FIGS. 7(a) and 7(b) are photographs of the surfaces of the crystallized glass of Example 2 and Comparative Example 1, respectively, after evaluation of contamination resistance.

First, the surface of each crystallized glass specimen is contaminated with an oil pen or 4B pencil, maintained for 15 minutes, wiped with a 1 kg load using a wiper medium (Yuhan Kimberly), and visually observed according to the criteria shown in Table 3 below. It was observed. After evaluation, the moisture on the surface of the specimen was removed by wind to minimize the change in surface condition due to friction.

Evaluation score Remark Evaluation results A No change Example 2 B Pollution traces remain faint - C Some traces of contamination are erased - D Clear traces of contamination - E No traces of contamination are erased Comparative Example 1

The above description of the present invention is for illustration only, and a person having ordinary knowledge in the technical field to which the present invention pertains can understand that it can be easily modified into other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined form.

The scope of the present invention is indicated by the following claims, and all modifications or variations derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present invention.

Claims (11)

In the crystallized glass comprising an oxide, a rare earth oxide and a colorant represented by the following formula,
The content of the rare earth oxide in the crystallized glass is 1 to 15% by weight,
The rare earth oxide crystallized on the surface of the crystallized glass to have a hydrophobic crystallized glass:
<expression>
A _x O _y
In the above formula,
A is one or more selected from the group consisting of Si, Li, P, Al, B and Zr,
x and y are each an integer of 1 to 5 satisfying the above formula. According to claim 1,
The oxide is SiO ₂ 65.0 ~ 75.0 wt%, Li ₂ O 10.0 ~ 15.0 wt%, P ₂ O ₅ 3.0 ~ 5.0 wt%, Al ₂ O ₃ 1.0 ~ 5.0 wt%, B ₂ O ₃ 3.0 ~ 6.0 wt%, And ZrO ₂ 0.01 to 3.0% by weight. According to claim 1,
The rare earth oxide is cerium (Ce), dysprosium (Dy), erbium (Er), europium (Eu), gadolinium (Gd), holmium (Ho), lanthanum (La), ruthenium (Lu), neodymium (Nd), Praseodymium (Pr), Promethium (Pm), Samarium (Sm), Scandium (Sc), Terbium (Tb), Thulium (Tm), Ytterbium (Yb), Yttrium (Y), and combinations of two or more of these. Crystallized glass, which is one selected oxide. According to claim 1,
The content of the colorant in the crystallized glass is 1 to 6% by weight of crystallized glass. According to claim 1,
The colorant is a crystallized glass that is one selected from the group consisting of TiO ₂ , Fe ₂ O ₃ , V ₂ O ₅ , V ₂ O ₃ , TaO ₂ , MnO ₂ and combinations of two or more of them. According to claim 1,
The crystallized glass having a contact angle with water on the surface of the crystallized glass of 60° or more. a) preparing a mixture comprising an oxide represented by the following formula, a rare earth oxide, and a colorant;
b) heat-treating the mixture at 450-550° C. for 1-2 hours to form a nucleus; And
c) a step of growing crystals by heat treatment at 600 to 800° C. for 1 to 2 hours;
<expression>
A _x O _y
In the above formula,
A is one or more selected from the group consisting of Si, Li, P, Al, B and Zr,
x and y are each an integer of 1 to 5 satisfying the above formula. The method of claim 7,
The oxide is SiO ₂ 65.0 ~ 75.0 wt%, Li ₂ O 10.0 ~ 15.0 wt%, P ₂ O ₅ 3.0 ~ 5.0 wt%, Al ₂ O ₃ 1.0 ~ 5.0 wt%, B ₂ O ₃ 3.0 ~ 6.0 wt%, And ZrO ₂ 0.01 to 3.0% by weight. The method of claim 7,
The rare earth oxide is cerium (Ce), dysprosium (Dy), erbium (Er), europium (Eu), gadolinium (Gd), holmium (Ho), lanthanum (La), ruthenium (Lu), neodymium (Nd), Praseodymium (Pr), Promethium (Pm), Samarium (Sm), Scandium (Sc), Terbium (Tb), Thulium (Tm), Ytterbium (Yb), Yttrium (Y), and combinations of two or more of these. Method for producing crystallized glass, which is one selected oxide. The method of claim 7,
Method of producing a crystallized glass content of the colorant in the mixture is 1 to 6% by weight. The method of claim 7,
The colorant is TiO ₂ , Fe ₂ O ₃ , V ₂ O ₅ , V ₂ O ₃ , TaO ₂ , MnO ₂ and a method for producing a crystallized glass that is one selected from the group consisting of two or more of them.

Images