WO2001083390A1

WO2001083390A1 - Glass ceramic, use thereof and denture

Info

Publication number: WO2001083390A1
Application number: PCT/JP2001/003797
Authority: WO
Inventors: Masatoshi Yamazoe; Hidekazu Tanaka; Takeshi Hoshikawa; Hirohisa Yamamoto; Teruo Anraku
Original assignee: Yamamoto Precious Metal Co., Ltd.
Priority date: 2000-05-02
Filing date: 2001-05-02
Publication date: 2001-11-08
Also published as: AU2001255063A1; JP2001316130A

Abstract

A glass ceramic, characterized in that it is a luecite glass ceramic containing luecite crystals and 0.1 to 1.4 wt % of a CeO2 component and it is substantially insusceptible to yellowing when the powder thereof is applied to the surface of an alloy containing silver and is welded by fusion. The glass ceramic is useful as a porcelain for use in preparing a denture excellent in appearance by piling it up on the surface of a metal frame and welding it by fusion.

Description

Specification

Glass ceramics, their use and dentures

Technical field

The present invention relates to glass ceramics, their use and dentures. The pulverized glass ceramic (powder) according to the present invention is laid on a frame made of a precious metal alloy containing silver, and is coated by welding to produce a denture with excellent aesthetic properties. It is useful as porcelain that does not substantially occur.

Background technology

Technology has been developed to build a porcelain powder on the surface of a metal frame and weld it to produce a denture with the same appearance as natural teeth and excellent mechanical and chemical durability.

While noble metal alloy as a metal carrier material have conventionally been used, inexpensive silver (thermal expansion coefficient from the economics: about ^{20 X 1 (T 6 Z *} ) gold-silver alloy containing palladium silver alloy universal are, their thermal expansion coefficient from 13.6 to 15. is in the range of 2 X 10- ⁶ Z. the bridge of denture brazing containing silver has become mainstream.

Therefore, the porcelain powder that is laid and fused on the surface of the metal frame has a thermal expansion coefficient that is very close to the high thermal expansion coefficient of the metal frame material, and reproduces the same appearance as natural teeth. It is required to have the transparency necessary for adding colors for the purpose.

Therefore, ceramic from the viewpoint of high thermal expansion and transparency, Liu site crystals _{_{_{(4Si0 2 · A1 2 0 3}}} · K 2 0) glass ceramics containing found that built up city on the surface of the silver alloy frame is熔着Used as a material.

However, when glass ceramic powder is welded to a silver alloy frame, there are the following disadvantages. In other words, in the process of fusing glass-ceramic powder onto a silver alloy frame, silver diffuses into the high-temperature glass matrix and dissolves in a colorless state, but its solubility decreases upon cooling to form silver coronds. Therefore, it is inevitable that glass ceramics are colored yellow to brown (yellowing). In addition, the yellowing of the glass ceramics also occurs due to the furnace contaminated with silver. Conventionally, various techniques have been developed to suppress yellowing of porcelain. For example, JP-A-63-31805 discloses a technique for mixing a nitrate compound in porcelain. However, according to the technique described in Japanese Patent Application Laid-Open No. 63-310805, since the nitrate is unlikely to be present in a high-temperature porcelain in a stable state, the effect of suppressing yellowing is not always exhibited. However, the certainty of the manifestation of the effect of suppressing yellowing is poor.

JP-A-3-5410, JP-A-3-11005, JP-A-3-81212, and the like disclose techniques for mixing antimony trioxide into porcelain. However, antimony trioxide is a harmful compound to the human body and has safety and health problems.

Disclosure of the invention

It is an object of the present invention to stably suppress yellowing or prevent yellowing when a denture is manufactured by welding and coating a vitreous material on a silver alloy frame, and furthermore, there is a problem in safety and health. It is an object of the present invention to provide a glass ceramic containing a leucite crystal having no defects. Another object of the present invention is to provide a metal ceramic obtained by laying the above-mentioned leucite crystal-containing glass ceramic on the surface of a metal frame and welding it. intensive lotus research to achieve the above object, proof results, have found that by incorporating a specific amount of CeO ₂ component in the glass ceramic box, desired glass ceramics capable of suppressing yellowing is obtained The present invention has been completed based on such findings.

According to the present invention, there is provided a leucite vitreous ceramics containing CeO ₂ component from 0.1 to 1.4 wt%, it was applied to the powder to the alloy-out ί surface containing silver, and heated熔着Provided is a glass ceramic having a property capable of suppressing or preventing yellowing when the glass ceramic is used.

According to the present invention, the leucite crystals contained 15 to 43 wt%, 50~500t:. Coefficient of thermal expansion that put a has 12 to 17 5 X 10- ⁶ 3, in after heating 850 in 3 hours Also provided is a glass ceramic as described above, wherein no Na · K feldspathic crystals are precipitated. According to the present invention, (1) Si0 ₂ 53~65 wt%, A 0 ₃ K -~ 23 wt%, K ₂ 0 9~20 by weight%, Na ₂ 0 6~12 wt%, L i zO 0 2 wt%, gO 0~3 weight%, CaO 0~3 weight%, B ₂ 0 ₃ 0~3 weight%, BaO 0~3 weight%, P ₂ 0s! .) To 2 wt%, F 0 to 2 wt% and CeO ₂ 0. 1 to 1 4% by weight and a glass raw material powder containing _{(2) S i0 2 5:} ; ~ 64 wt%, A Os. 19 to 27 wt%, K ₂ 0 17~25 wt%, Rb ₂ 0 0~5 wt%, Na ₂ 0 0~2 wt%, Li ₂ 0 0~2 wt %, MgO 0 to 3% by weight and CaO (! To 3% by weight, mixed with synthetic leucite crystal powder, and heat treated at 750 to 950 for 1 to 5 hours. Glass ceramics are provided.

According to the present invention, there is provided a denture obtained by laying the above-described glass ceramic on the surface of a metal frame and welding the glass ceramic.

The glass ceramic containing the leucite crystal of the present invention is a glass ceramic having a high thermal expansion property and substantially not causing yellowing when welded to a silver alloy at a high temperature.

Ryu one site crystals contained in the glass ceramics of the present invention, Li Yu site crystals theoretical composition, Si0 ₂ K of leucite solid solutions and the leucite crystal component was dissolved is partially substituted Rb At least one selected from crystals. Unless otherwise specified below, simply if as "leucite crystal", contains crystals K of Si0 ₂ Ryu one site solid solution component was dissolved and the leucite in the crystal is partially substituted Rb It is assumed that

Glass ceramics containing leucite crystals of the present invention, an essential requirement that contains CeO ₂ component from 0.1 to 1.4 wt%. The ce0 _2-component 0.1 to 1.4 only when containing wt%, can achieve the above object of the present invention. If the content of the Ce0 _two component is more than 1.4% by weight, the glass ceramics will be milky or opaque, and the transparency will be impaired. If the content of CeO ₂ component is less than 1 wt% 0., yellowing occurs when熔着at a high temperature silver alloy.

Glass ceramics containing leucite crystals of the present invention is preferably from contains a CeO ₂ component from 0.1 to 1.2 wt%, 0.5 to 1.1 of containing wt% is especially Preferred.

Glass ceramics containing leucite crystals of the present invention as described above, as CeO ₂ component content one site crystal-containing glass-ceramics Ryu is in the above range, Tokoro vitreous material in producing the glass ceramic by blending the CeO ₂ component of quantitation, it can be easily produced.

The leucite crystal-containing glass ceramic of the present invention preferably has the following properties during the welding operation to the silver alloy frame. (1) Leucite crystal-containing glass ceramics in which the amount of leucite crystals (saturated state) does not change

(2) Heterogeneous crystals such as Na 長 K feldspar crystals do not precipitate, that is, it takes a long time until precipitation of heterocrystals such as Na NaK feldspar crystals starts after saturation of reusite crystals reaches saturation. Be a glass ceramic containing leucite crystals

(3) Leucite with reduced thermal expansion coefficient and no emulsification of glass ceramics

(4) A glass-ceramic that does not precipitate Na · K feldspar crystals even after heating at 850 for 3 hours (ie, is transparent and does not fluctuate in thermal expansion coefficient)

Glass ceramics having such properties are manufactured, for example, by the following method.

That is, the above-mentioned glass ceramic is produced by mixing a vitreous raw material and a synthetic leucite crystal (seed crystal) and subjecting it to a heat treatment.

Glassy material, for example Si0 ₂ fifty-three to sixty-five wt%, AH0 ₃ 13 to 23 wt%, K ₂ 0 9 to 20 by weight%, Na ₂ 0 6 to 12 wt% and Ce0 ₂ 0. 1~1. 4 good glassy material comprising by weight% as essential components, as in addition to optional components of the component L 0, Mg0, CaO, B 2 0 3, BaO, may contain P ₂ (k F and the like. for example L hO 2 wt% or less, MgO is 3 wt% or less, CaO 3 wt% or less, 3 wt% or less, BaO is 3 wt% or less, ₂ 0 ₅ 2 wt% or less, F is a double amount% less is good is. also, the total content of any component of vitreous is usually 6 by weight% or less is good is. CeO ₂ facilitates clarification of vitrification and glass of the raw material powder It also has the effect.

The vitreous raw material is prepared by a usual melting method. For example, suitable starting materials such as oxides, hydroxides and carbonates are mixed in a desired weight ratio and melted at 1550-1650 ° C. for 2-5 hours.

The vitreous raw material is preferably a pulverized product. The pulverized material, for example, is obtained by pouring the molten glass prepared above into water, pulverizing it, drying it, and further pulverizing it to a desired particle size or less with a crusher such as a ball mill.

Synthesis Ryu one site crystals, for example, S i 0 ₂ 53~64 wt%, A 0 ₃ 19 to 27 wt% and Κ ₂ 0 Π~25 synthesis including the weight% as an essential component Ryusai preparative good crystal, the component In addition, Rb ₂₀ , Na ₂₀ , Li ₂₀ , Mg0, CaO and the like may be contained as optional components. Rb ₂ 0 0 to 5 wt% or less For example, Na ₂ 0 2 wt% or less, L i ₂ 0 2 wt% or less, MgO is better to 3% by weight and CaO is 3 wt% or less. In addition, the total content of optional components in the synthetic leucite crystal should generally be 5% by weight or less (

The synthetic leucite crystal is also prepared by a usual melting method, similarly to the glassy material I. For example, appropriate starting materials such as oxides, hydroxides, and carbonates are mixed in a desired weight ratio, melted at 1700 or more at a temperature of 2 hours or more, and then gradually cooled to 1200 ° C to crystallize. After completion of the reaction, cool to room temperature. The completion of crystallization is confirmed by powder X-ray diffraction analysis.

The synthetic leucite crystals are preferably ground. For the pulverization, for example, the high-temperature synthetic leucite crystal produced above is put into water together with a crucible, quenched and crushed, the crystal part is collected, dried, and then subjected to a desired particle size (75 μm) using a crusher such as a ball mill. πι or less).

The particle size of the pulverized synthetic leucite crystal used as a seed crystal in the present invention is not limited. For example, the object of the present invention can be achieved if the average particle size of the pulverized synthetic leucite crystal is 75 or less.

The glass ceramic of the present invention is produced by mixing the vitreous raw material prepared above with a synthetic leucite crystal (seed crystal) and subjecting it to crystallization heat treatment, for example, usually for 800 to 901), usually for 1 to 3 hours. You.

As for the mixing ratio of the vitreous raw material and the synthetic leucite crystal, the latter is usually 0.5 to 5% by weight, preferably! It is better to be 2% by weight.

The leucite crystal-containing glass ceramic of the present invention produced by the above method is a glass ceramic containing a leucite crystal having an average particle diameter of 20 m or less. In this glass ceramic, a leucite crystal having an average particle diameter of 20 mm or less is precipitated in a glass matrix in a state of being saturated or almost saturated, and the crystal is dispersed as a metastable crystal phase.

The amount of leucite crystals contained in the glass ceramic of the present invention produced by the above method is usually 15 to 43% by weight. The coefficient of thermal expansion of the glass ceramics of the present invention in the range of 50 to 500 is the same as that of the glass ceramics. Not it may vary depends on the amount of one site crystals, it is usually 12~Π. 5 Χ 10- ⁶ Ζ.

The glass-ceramics of the present invention produced by the above-mentioned method have the same amount of leucite crystals (saturated state) during the welding work to the metal frame, and also have different types of crystals such as Na-K feldspathic crystals. No precipitation occurs, and it takes a long time after precipitation of leucite crystals reaches saturation to start precipitation of heterogeneous crystals such as Na-K feldspar-like crystals. Also, this glass ceramic does not cause a decrease in the coefficient of thermal expansion of the glass ceramic and no emulsification during the welding operation to the metal frame. When the glass ceramic of the present invention is used, for example, for dental use, the glass ceramic is once formed into a powder form, and then formed into a compact or sintered body.

At least one additive selected from an emulsifier, a coloring pigment, a phosphor, a wetting agent and a kneading agent can be added to the glass ceramic powder of the present invention.

Known emulsifiers, coloring pigments, phosphors, wetting agents and kneading agents can be widely used. The amounts of these additives are not limited as long as they do not impair the effects of the present invention.

In using the glass ceramic powder of the present invention for dental use, the same usage method as that of the conventional porcelain can be adopted. For example, the above-mentioned powder can be laid on a metal frame, welded, and then repeatedly colored, fired, modified in shape, and fired to form a denture with excellent aesthetics. In the glass ceramics of the present invention, a series of these steps, for example, firing (specified in JIST 6516 (the firing conditions are specified by the manufacturer); 60 (put in a furnace of T, vacuum (approximately 30 Hg), raise the temperature to 900 in 60 minutes, hold it for 1 minute, take it out to the atmosphere and let it cool down) about 10 times (g firing time = about 1 hour) The amount of leucite crystals in the glass ceramic does not change, so that the glass ceramic sintered body has an excellent coefficient of thermal expansion and excellent transparency.

The glass ceramics of the present invention is effective when applied to precious gold alloys containing silver, for example, gold-silver alloys, palladium-silver alloys, gold-silver-palladium alloys, etc., but high expansion noble metal alloys (gold-high carat alloys, gold It is also applicable to medium carat alloys, gold-palladium alloys, palladium alloys, etc., and can produce dentures with excellent functionality. One example of a desirable method for producing an artificial denture is as follows. First, an operation powder is kneaded using a water-soluble kneading solution, applied on a metal frame, dried, and then baked in a vacuum (900 In). Next, dentin corresponding to the dentin of the natural tooth is kneaded and applied in the same manner, and the applied layer is shaved in a semi-dry state, shaped, dried, and fired. In addition, the enamel is also subjected to a similar process to obtain a denture shape having an appearance that is in harmony with a desired natural tooth. Further, an artificial denture of any shape and color can be produced by applying a thin glaze, drying and baking.

The invention's effect

By using the glass ceramics of the present invention, yellowing due to silver can be substantially prevented in the process of welding to a silver alloy frame. In the present invention, such an effect of preventing yellowing can be stably exhibited. In addition Ce0 ₂ is harmless to the human body, it is a health safety.

The glass ceramic of the present invention is excellent in optical transparency, but further contains 50% by weight or more of a glass phase. Therefore, since the glass ceramics of the present invention are excellent in sinterability, defoaming easily occurs by low-pressure sintering, and further, excellent in wettability with metal surfaces and high in welding strength can be obtained.

Also, the pulverized and sized particles of the glass ceramic of the present invention surprisingly show softening fluidity by heating even when a large amount of an emulsifier, a colored inorganic pigment, a phosphor or the like is added. This is basically due to the fact that it contains a large amount of glass phase. By utilizing this feature, the color tone of the metal frame is concealed (opaque) and the color tone of natural teeth is reproduced (dentin-dentin, enamel-enamel) It is possible to adjust the addition amount of the colored pigment powder over a wide range so that the glaze can be developed in an advantageous manner.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be further clarified with reference to examples.

First, the basic composition of vitreous raw materials and the composition of leucite crystals (seed crystals) used in the following Examples and Comparative Examples are shown below.

The base composition of crow feedstock N o 1:. S 1 O 63. 7 wt%, A Oa 15. 0 wt%, K ₂ 0 1 0. 7 wt%, Na ₂ 0 8. 5 wt%, MgO 0. 3 wt%, CaO 1. 2% by weight and M) ₃ 0. 6 by weight% Basic composition No. crow feedstock _2: Si0 2 62. 1 wt%, A1 ₂ 0 ₃ 15. 0 wt%, K ₂ 0 1 1. 8 wt%, Na ₂ 0 9. 0 wt%, MgO 0. 3 wt%, CaO 1. composition of 2 wt% and 0.6 fold leucite crystals (seed crystals): Si0 ₂ 55. 1 wt%, a 0 ₃ 23. 3 wt% and K ₂ 0 21. 6 wt%

Examples 1-4

Glassy material is a composition obtained by replacing the Si0 ₂ component 0.1 to 1% by weight of the basic composition No. 1 or No. 2 of the as CeO ₂ component.

100 parts by weight of vitreous raw material (particle size ガラス, / πι or less) and powder of reusite crystal (seed crystal) (particle size = 75 ^ m or less): parts by weight as shown in Table 1 below Were mixed and subjected to crystallization heat treatment at 850 for 2 hours, and then cooled to produce the glass ceramic of the present invention.

Comparative Example 1

Ce0 except not to contain _two components, it was produced glass ceramics in the same manner as in Example 1.

Comparative Example 2

It was replaced as internal 0.05 wt% CeO ₂ component of Si0 _z component of the basic composition No. 1 described above, to produce a glass ceramic in the same manner as in Example 1.

Comparative Example 3

But replacing inner 1.5 wt% of Si0 ₂ component of the basic composition No. 1 of the as CeO ₂ component, to produce a glass ceramic in the same manner as in Example 1.

Comparative Example 4

The above basic composition N o. The replaced except 2% by weight of the first Si0 ₂ component as CeO ₂ component, to produce a glass ceramic in the same manner as in Example 1.

Comparative Example 5

The above basic composition N o. Except that 4 wt% of the second Si0 ₂ component was replaced as CEC ₂ components were prepared glass ceramics in the same manner as in Example 4.

Each of the glass ceramics obtained in the above Examples and Comparative Examples was ground to a particle size of 75 am or less, the powder was laid on the bottom of a mold, and silver flakes (thickness = 0.05 thigh, 3X3 mm) were placed horizontally. After covering with powder, it was formed by a biaxial press. Vacuum firing was performed based on JIS T 6516 regulations. That is, after placing the compact obtained above in a furnace at 600 ° C and evacuating, 6 (Temperature was raised to 900 by TCZ, heated at 900 for 1 minute, then sintered, then taken out to the atmosphere This vacuum firing was performed once and then air firing was performed once, and the sample was fired twice, and the above vacuum firing was performed three times and air firing was performed once. The sample was fired four times.

With respect to the sample fired four times, the color tone of the surface of the metallic silver flake was visually observed.

Further,〗 IS T 6516 thermal expansion coefficient by the method defined was measured (ratio:: X 10- ⁶ /, while the average value at 50 to 500). alpha ₂ is twice the thermal expansion coefficient of the fired samples, alpha ₄ is the thermal expansion coefficient of 4 times fired samples.

Table 1 shows the results.

Table 1 Basic composition Ce0 ₂ Visual appearance Thermal expansion coefficient

No. (wt%) a:? . 1

Example 1 1 0.1 Colorless and transparent 1 3.8 13.8 Example 2 1 0.1 Colorless and transparent 1 3.4 13.4 Example 3 1 1.0 Colorless and transparent 1 3.4 13.4 Example 4 2 0.5 Colorless and transparent 16.8 16.8 Comparative example 1 10 Yellow and transparent 13.8 13.8 Comparative example 2 1 0.05 Light yellow and transparent 1 3.8 13.8 Comparative Example 3 1 1.5 Colorless, pale milky 1 3.4 13.4 Comparative Example 4 1 2.0 Colorless, slightly milky 1 3.4 13.4 Comparative Example 5 2 4.0 Strong white turbidity 16.5 16.5 In Examples 1 to 4, the silver surface did not turn yellow and no emulsification occurred.

As in Comparative Examples 1 and 2, when Ce (the amount of the component added was small (0.05% by weight or less)), yellowing was clearly observed, and use was hindered.

Comparative Example 3-5 is an example amount of CeO ₂ component is great, opacifiers or emulsifying Oko Therefore, it could not be used in terms of transparency.

Even after the ceramics obtained in Examples 1 to 4 were repeatedly fired four times, different kinds of crystals such as NaK feldspar crystals did not precipitate, the coefficient of thermal expansion did not decrease, and emulsification occurred. It didn't work.

Claims

The scope of the claims

1 A leucite glass-ceramic containing 0.1-1.4% by weight of ₂ components. The yellowing is substantially caused when the powder is applied to the surface of an alloy containing silver and heated and welded. A glass ceramic characterized in that it has properties that do not occur in glass ceramics.

2 glass ceramic, leucite crystals 15-4:.. I contained by weight%, 50 to 500 "is 12 to 17 at 5 X 10- ⁶ thermal expansion coefficient in C, 8 '; (3 hours TC 2. The glass-ceramic according to claim 1, wherein the glass-ceramic does not precipitate Na · K feldspathic crystals even after heating.

3 (1) S i0 ₂ 53~65 wt%, AhOa 13~23 wt% K ₂ 0 9 to 20 wt%, Na ₂ 0 6~12 wt%, L i ₂ 0 0~2 wt%, MgO 0 to 3 wt%, CaO 0 to 3 wt%, B ₂ 0 ₃ 0 ~3 wt%, BaO 0 to 3 wt%, P ₂ 0 _s 0~2 wt%, F 0 to :! wt% and CeO ₂ 0. 1 to 1.4 glassy material powder and ₍₂₎ Si0 2 53~64 double containing wt% _{_{[amount%, A1 2 0 3 19 ~}} 27 wt%, K ₂ 0 17 to 25 wt%, Rb ₂ 0 0 to 5 wt%, Na ₂ 0 0 to 2 double ί weight%, L i ₂ 0 0 to 2 wt%, and a synthetic leucite crystal powder containing 0-3% by weight MgO and CaO 0-3 wt% 3. The glass ceramic according to claim 2, which can be obtained by heat-treating at 750 to 950 for 1 to 5 hours after mixing.

4. Use of the glass-ceramic according to any one of claims 1 to 3, for laying on a metal frame and forming a denture by welding and coating.

5. A denture obtained by laying the glass ceramic according to any one of claims 1 to 3 on a surface of a metal frame and welding.