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    • 专利摘要:
    The invention relates to a maximum impurities BaO and PbO-free radiopaque glass having a refractive index n d of 1.50 to 1.58 and a high radiopacity with a Aluminiumgleichwertdicke of at least 300%. The glass is based on the system SiO 2 - Al 2 O 3 - SrO - R 2 O with additions of La 2 O 3 and ZrO 2. The glass has a very good chemical resistance and can be used in particular as dental glass or as optical glass.
    公开号:CH705618B1
    申请号:CH01492/12
    申请日:2012-08-27
    公开日:2016-08-31
    发明作者:Simone Monika Ritter Dr；Pichler-Wilhelm Sabine；Dobler Carina；Hansen Stefanie
    申请人:Schott Ag；
    IPC主号:
    专利说明:

    The invention relates to a barium and lead-free radiopaque glass and its use.
    In the dental field, plastic dental compositions are increasingly being used for tooth restoration. These plastic dental compositions usually consist of a matrix of organic resins and various inorganic fillers. The inorganic fillers mainly consist of powders of glasses, (glass) ceramics, quartz or other crystalline substances (e.g. YbF3), sol-gel materials or aerosils and are added to the plastic mass as filler material.
    The use of plastic dental compositions is intended to avoid possible harmful side effects of amalgam and to achieve an improved aesthetic impression. Depending on the selection of plastic dental materials, they can be used for different tooth restoration measures, for example for tooth fillings and also for fixings such as crowns, bridges and inlays, onlays etc.
    The filling material as such should minimize the shrinkage caused by the polymerization of the resin matrix during curing. For example, if there is strong adhesion between the tooth wall and the filling, excessive polymerization shrinkage can lead to breakage of the tooth wall. If the adhesion is not sufficient for this, excessive polymerization shrinkage can lead to the formation of marginal gaps between the tooth wall and the filling, which can promote secondary caries. In addition, certain physical and chemical requirements are placed on the fillers:
    It must be possible to process the filler material into as fine powders as possible. The finer the powder, the more homogeneous the appearance of the filling. At the same time, the polishability of the filling is improved, which, by reducing the attack surface, leads to improved abrasion resistance and thus to a longer shelf life of the filling. In order for the powders to be easy to process, it is also desirable for the powders not to agglomerate. This undesirable effect occurs in particular with filler materials that have been produced with the aid of sol-gel processes.
    Furthermore, it is advantageous if the filler is coated with a functionalized silane, since this facilitates the formulation of the dental material and improves the mechanical properties. The surfaces of the filler particles are usually at least partially covered with the functionalized silane.
    In addition, the plastic dental compound in its entirety and thus also the filler should be adapted as well as possible to the natural tooth material in terms of their refractive index and color, so that they can be distinguished as little as possible from the surrounding healthy tooth material. The smallest possible grain size of the pulverized filler also plays a role for this aesthetic criterion.
    It is also important that the thermal expansion of the overall system of plastic dental compound and the glass material contained therein as filler in the area of use, i.e. usually between -30 ° C and +70 ° C, which is adapted to that of the natural tooth material, in order to ensure that the tooth restoration measure is sufficiently resistant to changes in temperature. Excessive thermal alternating loading can also result in gaps between the plastic dental compounds and the surrounding tooth material, which in turn can represent preferred points of attack for secondary caries.
    As a rule, fillers with the lowest possible thermal expansion coefficient are used in order to compensate for the large thermal expansion of the resin matrix.
    Good chemical resistance of the fillers to acids, alkalis and water as well as good mechanical stability under loads such as e.g. Due to the chewing movement, it can also contribute to a long service life of the dental restoration measures. The fillers should also be resistant to dental treatments with fluorine.
    For the treatment of patients, it is also absolutely necessary that dental restoration measures are visible in the X-ray image. Since the resin matrix is usually invisible in the X-ray image, the fillers must ensure the necessary X-ray absorption. Such a filler that absorbs X-rays sufficiently is called X-ray opaque. Components of the filler, for example certain components of a glass, or additives are usually responsible for the radiopacity. Such additives are also called radiopaque. A common X-ray opaquer is YbF3, which can be added in crystalline, ground form.
    The radiopacity of dental glasses or materials is specified according to DIN ISO 4049 relative to the X-ray absorption of aluminum as the aluminum equivalent thickness (ALGWD). An ALGWD of 200% means that a glass plate with plane-parallel surfaces 2 mm thick causes the same X-ray attenuation as an aluminum plate 4 mm thick. Analogously, an ALGWD of 500% means that a glass plate with plane-parallel surfaces 2 mm thick causes the same X-ray attenuation as an aluminum plate 10 mm thick.
    Because the plastic dental compound is usually filled into cavities from cartridges and modeled there, it should often be thixotropic in the uncured state. This means that its viscosity decreases when pressure is exerted, while it is dimensionally stable without the application of pressure.
    In the case of plastic dental compositions, a distinction must also be made between dental cements and composites. In dental cements, also called glass ionomer cements, for example, the chemical reaction of the fillers with the organic matrix leads to the hardening of the dental compound, which is why the reactivity of the fillers influences the hardening properties of the dental compound and thus its machinability. This is often a setting process that can be preceded by radical surface hardening, for example under the action of UV light. The glass can serve as a filler, which triggers the chemical reaction or is involved in it, or as an inert additive that is not involved in the reaction. The chemical reaction is then caused by other fillers also contained in the glass ionomer cement.
    Composites, also called filling composites, contain, on the other hand, more extensive chemically largely inert fillers, since their hardening behavior is initially determined by components of the resin matrix itself and a chemical reaction of the fillers and / or additives is often disruptive for this.
    Because glasses, due to their different compositions, represent a class of materials with diverse properties, they are often used as fillers for plastic dental compounds. Other applications as dental material, either in pure form or as a component of a material mixture, are also possible, for example for inlays, onlays, veneering material for crowns and bridges, material for artificial teeth or other material for prosthetic, conservative and / or preventive dental treatment. Such glasses when used as a dental material are generally called dental glasses.
    In addition to the properties of the dental glass described above, freedom from barium oxide (BaO) because of possible harmful side effects and the toxic lead oxide (PbO) are also desirable.
    [0018] It is also desirable that the dental glasses contain zirconium oxide (ZrO2) as a component. ZrO2 is a widely used material in the technical application areas of dental technology and optics. ZrO2 is very biologically compatible and is characterized by its insensitivity to temperature fluctuations. It is used for many dental restorations in the form of crowns, bridges, inlays, attachments and implants.
    Dental glasses thus represent particularly high-quality glasses. Such glasses can also be used in optical applications, in particular when the application benefits from the X-ray opacity of the glass. Since the X-ray opacity means that the glass absorbs electromagnetic radiation in the range of the X-ray spectrum, corresponding glasses are also filters for X-rays. X-rays can damage sensitive electronic components. In the case of electronic image sensors, the passage of an X-ray quantum can, for example, damage the corresponding area of the sensor or lead to an undesired sensor signal, which can be perceived, for example, as an image disturbance and / or interfering pixel. Therefore, for certain applications it is necessary or at least advantageous to protect the electronic components from the X-rays by filtering them out of the spectrum of the incident radiation using appropriate glasses.
    Numerous dental glasses and other optical glasses with a similar optical position or a comparable chemical composition are described in the prior art, but these glasses have considerable disadvantages in production and / or use. In particular, many of the glasses contain larger proportions of fluoride and / or Li2O, which evaporate very easily during the melting and melting process, which makes it difficult to set the glass composition precisely.
    US 5,976,999 and US 5,827,790 relate to vitreous ceramic compositions i.a. in applications for dental porcelains. CaO and LiO2 must be contained in at least 0.5% by weight and 0.1% by weight, respectively. In addition to the two main additive components from the group ZrO2, SnO2 and TiO2, CaO with at least 0.5 wt. These components cause an increased refractive index and only a low radiopacity. The glasses of these two documents also contain at least 10% by weight of B2O3. The relatively high B2O3 content in combination with the alkali content of at least 5% by weight or at least 10% by weight leads to the chemical resistance of the glass deteriorating in an unacceptable manner and therefore being unsuitable for dental glasses.
    Chemically inert dental glasses for use as fillers in composites are the subject of DE 19 849 388 A1. The glasses proposed there necessarily contain significant proportions of ZnO and F. The latter can lead to reactions with the resin matrix, which in turn can affect its polymerization behavior. In addition, the SiO2 content is limited to 20–45% by weight, so that sufficient X-ray opaquer and F can be contained in the described glass.
    [0023] WO 2005/060 921 A1 describes a glass filler which is said to be particularly suitable for dental composites. This contains 9 to 20 mol% alkali metal oxides. The aim of this document is to provide glass particles whose alkali ion concentration is lower at the edge of the particles than in their center. This means that the glasses described cannot be chemically resistant, because otherwise this concentration behavior would not be achievable. It can be assumed that the required low chemical resistance is achieved by the stated proportions of alkali metals in the starting glass.
    [0024] An alkali silicate glass which serves as a filler for dental material is described in EP 0 885 606 B1. The Al2O3 content of at least 5% by weight increases the viscosity in glass with a high SiO2 content and therefore leads to very high melting temperatures. The glasses still contain fluorine. However, fluorides tend to evaporate easily when the glass is melted, which makes precise adjustment of the glass composition difficult and leads to inhomogeneity. In addition, the proportion of the component CaO, which gives the glass radiopacity, is 0.5 to 3% by weight too low to achieve the required radiopacity with an ALGWD of at least 300%.
    DE 4 443 173 A1 comprises a glass with a high zirconium content with a ZrO2 content of more than 12% by weight and other oxides. Such fillers are too reactive, especially for the most modern epoxy-based dental materials, which can harden too quickly and in an uncontrolled manner. Zirconia in this amount tends to devitrify. It causes phase segregation with possible nucleation and subsequent crystallization. In addition, the production of such glasses is only possible with high alkali contents in order to ensure that the melting temperature is not too high, which would overstrain the melting units. However, such high alkali contents in turn have a detrimental effect on the chemical resistance of the glasses.
    DE 19 945 517 A1 also describes a glass with a high zirconium content, which, when used in the dental field, has the same problems as the glasses of the aforementioned document.
    JP 2004-002 062 A discloses a glass substrate for flat screens. In addition to SrO, the glasses disclosed predominantly contain BaO and all of them contain high proportions of Al2O3 and MgO. The components Al2O3, SrO, BaO and MgO are required as network converters to ensure the meltability of the glass. These glasses are also not suitable for use as dental glasses because they may contain BaO or, in the low-BaO variants, do not have the required radiopacity by far. Apart from that, the Al2O3 content means that the viscosity is increased in glass with a high SiO2 content and therefore high melting temperatures are required for production. High contents of MgO are disadvantageous in glasses for dental applications, which should have low refractive index and at the same time high radiopacity. MgO does not increase the X-ray opacity to the same extent as the other alkaline earth oxides CaO, SrO and BaO, but is mainly noticeable in an increase in the refractive index and can thus complicate the desired balance between low refractive index and high X-ray opacity.
    The glasses mentioned in the prior art have in common that they are either not very weather-resistant or too reactive and / or are not radiopaque or contain components that are harmful to the environment and / or health.
    The object of the invention is to provide a barium- and lead-free, radiopaque, relatively low-refractive-index glass with a refractive index nd of 1.50 to 1.58. The glass should be suitable as dental glass and as optical glass. It should be inexpensive to manufacture and yet be of high quality and biocompatible as well as suitable for passive and active tooth protection and have excellent properties in terms of processability, the setting behavior of surrounding plastic matrices and long-term stability and strength. In order to meet the requirements in modern dental treatment and dental technology, the glass according to the invention must also have excellent chemical resistance.
    The glass according to the invention should furthermore be free of coloring components such as e.g. Fe2O3, CoO, NiO, CuO etc. in order to enable an optimal starting color point for possible adaptations to the tooth color and / or in optical applications the spectrum of electromagnetic radiation that passes through. In addition, it should be free of a second glass phase and / or color-imparting particles that lead to scattering and also change the color impression. One or more further glass phases would reduce the resistance of the glass.
    [0031] The object is achieved by the glass according to the independent claims. Preferred embodiments and applications emerge from the dependent claims.
    The glass according to the invention has a refractive index nd of 1.50 to 1.58. It is therefore very well adapted to the available dental plastics and / or epoxy resins in this refractive index range, as a result of which it perfectly satisfies the aesthetic requirements placed on a dental glass-plastic composite for a natural appearance.
    The glass according to the invention achieves the properties of barium and / or lead-containing dental glasses with regard to the required X-ray absorption without the use of barium and lead or other substances that are harmful to health. The term “free from” means freedom from these substances except for contamination that cannot be avoided, for example, due to air pollution and / or impurity of the raw materials used. But even a contamination of the glass with the undesired substances must generally not exceed 100 ppm for Fe2O3100 ppm, preferably at most 50 ppm, for PbO 30 ppm, for As2O35 ppm, for Sb2O320 ppm and others 100 ppm. BaO is always closely associated with the SrO in the raw material. Depending on the purity of the SrO raw material, the glass according to the invention can contain up to 0.37% by weight of BaO. These limits are encompassed by the phrase “free of at most impurities”. Of course, complete freedom from the undesirable substances mentioned in the glass according to the invention is particularly preferred.
    The X-ray absorption and thus the X-ray opacity is mainly achieved according to the invention by the content of SrO and the further components Cs2O and / or La2O3 and / or SnO2 and / or ZrO2, which in combination are 10% by weight or more in the glass according to the invention . In contrast to earlier dental glasses, which tried to achieve the radiopacity through the high content of a component that is as highly absorbent as possible, the radiopacity according to the invention is preferably achieved through the suitable combination of these components effective for the radiopacity. In this way, the particularly strict requirements for the optical properties of the glass as well as the very good chemical resistance can be achieved. Preferred for the content of SrO and the further components Cs2O and / or La2O3 and / or SnO2 and / or ZrO2 are at least 11% by weight, in particular 12% by weight, particularly preferably at least 15% by weight.
    SrO is always contained in the glass according to the invention. Its content is 4 to 17% by weight. The range from 4 to 16% by weight, particularly preferably from 5 to 15% by weight, very particularly preferably from 6 to 14% by weight, is preferred. According to the invention, SrO, in combination with other X-ray opaquers, ensures the good X-ray opacity of the glass. Although the X-ray absorption spectrum of SrO in glasses in the range of the usual tungsten X-ray tubes in the range of an operating voltage of 65 keV has a suboptimal course, it has surprisingly been shown that very good X-ray opacities can be achieved in the combination.
    The glass according to the invention has, inter alia, as a result of these measures, an aluminum equivalent thickness (ALGWD) of at least 300%, preferably at least 350%, particularly preferably at least 390%. This means that a glass plate made of the glass according to the invention with plane-parallel surfaces and a thickness of 2 mm causes at least the same X-ray attenuation as an aluminum plate 6 mm thick.
    As a basis, the glass according to the invention contains SiO2 in a proportion of 55 to 75% by weight as a glass-forming component. Higher contents of SiO2 can lead to disadvantageously high melting temperatures, while in addition the required radiopacity cannot be achieved. Lower levels can have a negative effect on chemical resistance. A preferred embodiment of the glass according to the invention provides a content of 56 to 74% by weight and particularly preferably more than 59 to 70% by weight of SiO2.
    B2O3 is only optionally provided in the glass according to the invention. It can be contained in the range from 0 to 9% by weight. B2O3 serves as a flux. In addition to the lowering effect on the melting temperature, the use of B2O3 also leads to an improvement in the crystallization stability of the glass according to the invention. Higher proportions than about 9% by weight are not recommended in this system in order not to endanger the very good chemical resistance. Preference is given to using from 0 to 7 and particularly preferably from 0 to 4% by weight B2O3. If B2O3 is contained in the glass according to the invention, it is preferred to also add a small proportion of more than 0.5% by weight alkali metal oxides to the glass in order to avoid undesired scattering in segregated areas analogous to the Tyndall effect.
    The glass according to the invention contains Al2O3 in the range from 0.5 to 4% by weight. Al2O3 enables i.a. good chemical resistance. However, an Al2O3 content of around 4% by weight should not be exceeded in order not to increase the viscosity of the glass to such an extent, especially in the hot processing area, that the glass is difficult to melt. The upper limit of Al2O33.5% by weight, particularly preferably even only 3% by weight, very particularly preferably even only 2% by weight.
    Alkali oxides can reduce the chemical resistance of a glass, but on the other hand they can be required in order to be able to melt the glass at all. According to the invention, the total content of the alkali oxides Li2O and / or Na2O and / or K2O is from 0.5 to 12% by weight, preferably from 0.5 to 11% by weight, particularly preferably from 2 to 10% by weight. , very particularly preferably from 3 to 9% by weight. The invention provides a balance of these alkali metals in the ranges mentioned. In particular, alkali oxides from the group Li2O and / or Na2O and / or K2O in the glasses according to the invention can counteract segregation of the glass matrix and thus undesired scattering analogous to the Tyndall effect. It therefore contains at least 0.5% by weight of the alkali oxides in total. In addition, the alkali oxides together with B2O3 facilitate the melting of the glass at acceptable temperatures. However, the maximum of 12% by weight of the alkali metal oxides mentioned should not be exceeded in order to be able to achieve the very high resistance of the glass according to the invention.
    In detail, the content of these alkali oxides is, according to the invention, from 0 to 2% by weight of Li2O, preferably from 0 to 1% by weight, particularly preferably from 0 to less than 1% by weight. The very low proportions of Li2O help to achieve the very good chemical resistance. Therefore, a particularly preferred glass is free of Li2O apart from at most impurities.
    The content of Na2O can be higher than that of Li2O. According to the invention, Na2O is from 0 to 7% by weight, preferably from 0 to 5% by weight and particularly preferably from 0 to 4 and very particularly preferably from 0 to 3% by weight.
    K2O can be contained in the glass according to the invention from 0 to 9% by weight. The range from 0 to 8% by weight, particularly preferably from 0 to 7 and very particularly preferably 0 to 6% by weight, is preferred. Li2O, Na2O and K2O can contribute in particular to better melting of a glass containing SiO2 and ZrO2.
    Cs2O also contributes to improving the fusibility, but according to the invention at the same time serves to increase the radiopacity and to adjust the refractive index. According to the invention, Cs2O is contained in a glass according to the invention from 0 to 15% by weight, preferably from 1 to 14% by weight and particularly preferably from 2 to 13% by weight and very particularly preferably from 3 to 12% by weight. The alkali metal Cs is more immobile in a glass matrix compared to the alkalis Li, Na, K and Rb. It is therefore triggered less strongly and therefore deteriorates the chemical resistance less than the above-mentioned alkali metals.
    The glass according to the invention can contain a limited proportion of alkaline earths from the group CaO and MgO. The proportion of CaO is 0 to 11% by weight, preferably 0 to 10% by weight and particularly preferably 0 to 8% by weight and more preferably 0 to 7% by weight. MgO is likewise optional and can be contained from 0 to less than 3% by weight, preferably from 0 to less than 2% by weight and particularly preferably from 0 to less than 1% by weight. A very particularly preferred embodiment provides that the glass according to the invention is free of MgO apart from at most impurities. As already described, MgO can be disadvantageous in glasses for dental applications, which should have low refractive indices and at the same time high radiopacity. MgO does not increase the X-ray opacity to the same extent as the other alkaline earth oxides CaO, SrO and BaO, because the X-ray absorption edge of MgO is far below this and only has little influence in the area of the tungsten X-ray tube used in medicine. MgO would only increase the refractive index and thus make the balance between low refractive index and high radiopacity more difficult.
    The glass according to the invention also necessarily contains ZrO2 in a proportion of more than 1 to at most less than 11% by weight. This zirconium content improves the mechanical properties and especially the tensile and compressive strength and reduces the brittleness of the glass. In addition, the component contributes to the radiopacity similar to the amount of SrO in the glass. However, contents that are too high can lead to the glass becoming more reactive, especially in the vicinity of dental plastics. In contrast, the glass should be at least largely inert to dental plastics, especially composites, and, for example, not interfere with their polymerisation behavior. A ZrO2 content of 1 to less than 10% by weight, particularly preferably 2 to 9.5% by weight, very particularly preferably 2 to 9% by weight, is preferred.
    Because ZrO2 is sparingly soluble in silicate glasses and segregation can therefore easily occur, the stated proportion of ZrO2 should not be exceeded. Segregated areas, which can arise when the ZrO2 content is too high, especially when the SiO2 content is high at the same time, act as scattering centers for light passing through, analogous to the Tyndall effect. In dental glasses, these scattering centers can interfere with the aesthetic impression, which is why segregated glasses are generally undesirable in dental applications, and in optical glass the scattering centers generally have a negative effect on transmission, so that segregated glasses are also undesirable in most optical applications . In addition, due to the differently composed phases and thus different leaching properties, segregated glasses can lead to a reduction in resistance.
    La2O3 is contained in the glass according to the invention from 1 to 10% by weight. As described, it provides, if necessary. together with SrO and ZrO2 and optionally Cs2O and / or optionally SnO2 for the X-ray opacity of the glass. The La2O3 content is preferably from 2 to 8% by weight, particularly preferably from 3 to 7 and very particularly preferably from 3 to 6% by weight.
    Just like Cs2O, SnO2 can be contained in the glass according to the invention as an optional component for achieving a high radiopacity with an ALGWD of at least 300%. This component also has the advantage that it does not increase the refractive index as much as La2O3 and / or Ta2O5. SnO2 is also used to set the low refractive index of 1.50 to 1.58 with a high radiopacity at the same time. It can therefore be contained in the glass from 0 to 4% by weight. It is preferably contained in a glass according to the invention from 0 to 3% by weight.
    It is provided that the glass according to the invention is optionally free of CeO2 and TiO2 except for at most impurities. Because of their absorption in the UV range, CeO2 and TiO2 shift the UV edge of the glass so that it can acquire an undesirable yellowish color.
    In order to achieve a high radiopacity and correspondingly particularly large values of the aluminum equivalent thickness, preferred embodiments of the glass according to the invention provide that SrO and Cs2O and La2O3 and ZrO2 and / or SnO2 in total to more than 18% by weight, preferably more than 20 % By weight, particularly preferably more than 21% by weight, very particularly preferably more than 22% by weight, are contained in the glass.
    In order to ensure that the glass does not segregate, it can be preferred that the numerical value of the ratio of the content of SiO2 to ZrO2 is at least 6.5, particularly preferably more than 7.
    WO3 and / or Nb2O5 and / or HfO2 and / or Sc2O3 and / or Y2O3 and / or Yb2O3 can preferably and optionally individually or in any combination of 0 to 3% by weight each, Ta2O5 optionally and in any combination of 0 to 5 wt .-%.
    The invention also provides that the glass according to the invention (apart from at most unavoidable impurities) is free of B2O3.
    As described, the glass according to the invention (except for at most the impurities described) is free of the undesired components BaO and such as e.g. PbO. The addition of other environmentally harmful and / or harmful substances is preferably avoided.
    In order to ensure particularly good meltability of the glass, the invention also provides that the sum of the contents of MgO and / or CaO and / or SrO is less than 17% by weight. If the glass is difficult to melt, the melting units are overloaded and the glass can only be melted with increased effort, which usually requires production. no longer makes it economical.
    In the case of a glass according to the invention, the glass transformation temperature Tg is preferably at least 570 ° C. The glass thus has a high temperature resistance, which makes it suitable for other areas of application, in particular described below.
    The linear thermal expansion coefficient α (20-300) measured in the temperature interval from 20 ° C. to 300 ° C. of the glass according to the invention is preferably less than 7⋅10 <–> <6> K <–> <1>. Due to the low coefficient of thermal expansion, the glasses according to the invention are able to compensate for the naturally strong thermal expansion of the plastics, especially when used as a filler material in plastics, so that the plastic dental compound has a resulting thermal expansion which is better adapted to the natural tooth material .
    As already described, the glasses according to the invention are particularly resistant to chemical attack, i.e. they are particularly chemically resistant. They preferably have an acid resistance S according to DIN 12116 of class 2 or better, an alkali resistance L according to DIN ISO 695 of class 1 and a water resistance HGB according to DIN ISO 719 of class 2 or better. The tests of alkali resistance L and acid resistance S are much more demanding than the previously used test standards DIN ISO 10629 and ISO 8424, so that the glasses according to the invention in particular have improved alkali and acid resistance.
    The invention also provides that the glasses according to the invention have very good resistance to attacks by NaF. The test method is explained in more detail below in this text in connection with the exemplary embodiments. The aim of this test is to check the resistance of the glasses to fluorine and / or fluorides. These substances can strongly attack glass, but are often used in tooth cleaning materials and / or for fluorination and / or strengthening of healthy tooth material, etc. used by the dentist.
    The glasses according to the invention are therefore all characterized by very good chemical resistance, which leads to great inertia in interaction with the resin matrix and thus to a very good longevity of the entire dental compound.
    According to a further preferred embodiment of the present invention, the glass according to the invention is also preferably free from other components not mentioned in the claims and / or this description. This means that, according to such an embodiment, the glass consists essentially of the components mentioned. The expression “essentially consists of” means that other components are present at most as impurities, but are not intentionally added to the glass composition as individual components.
    However, the invention also provides for the glass according to the invention to be used as the basis for further glasses in which up to 5% by weight of further components can be added to the glass according to the invention described. In such a case, according to the invention, the glass consists of at least 95% by weight of the glass described.
    It is of course also possible to adapt the color appearance of the glass by adding oxides which are customary for this purpose. Oxides suitable for coloring glasses are known to the person skilled in the art, for example CuO and CoO may be mentioned, which for these purposes can preferably be added from 0 to 0.5% by weight. In addition, by adding e.g. Ag2O from 0 to 3% by weight can be given an antiseptic function.
    The invention also comprises glass powder made from the glasses according to the invention. The glass powders are produced by known methods, as described, for example, in DE 4 100 604 C1. The glass powder according to the invention preferably has an average particle size of up to 50 μm, particularly preferably up to 20 μm. A mean grain size of 0.1 μm can be achieved as the lower limit, with smaller grain sizes naturally also being included in the invention. The aforementioned glass powder can serve as a starting material for the use of the glasses according to the invention as fillers and / or dental glasses in general.
    In a preferred embodiment, the surface of the glass powder is silanized using the customary methods. The silanization can improve the binding of the inorganic fillers to the plastic matrix of the plastic dental compound.
    As described, the glass according to the invention can preferably be used as dental glass. It is preferably used as a filler in composites for tooth restoration, particularly preferably for fillers based on epoxy resin, which require largely chemically inert fillers. The use of the glass according to the invention as an X-ray opaque in dental materials, in particular plastic dental materials, is also within the meaning of the invention. The glass according to the invention is suitable for replacing expensive crystalline X-ray opaquers such as, for example, YbF3. The glass according to the invention is also suitable and intended to be used as a filler in glass ionomer cements. It is also possible to use the glass according to the invention as an inert additive in glass ionomer cements. The use as inert aggregate in plastic-reinforced glass ionomer cements is particularly preferred. The plastic-reinforced glass ionomer cements are a class of materials that have been available for a few years and that show the hardening reaction of a cement, which can take a long time, but also a resin matrix that, like the previously described, contain composites in order to be initially hardenable .
    Accordingly, the glass according to the invention is preferably used to produce a dental glass-plastic composite containing dental plastic, the dental plastic preferably being a UV-curable resin based on acrylate, methacrylate, 2,2-bis- [4- (3-methacryloxy) -2-hydroxypropoxy) phenyl] propane (Bis-GMA), triethylene glycol methacrylate (TEGDMA), urethane methacrylate (UDMA), alcandiol dimethacrylate or cyanoacrylate base.
    The invention also includes the use of the glass according to the invention as an optical element which contains the glass according to the invention. All objects and in particular components that can be used for optical applications are understood as optical elements. These can be components through which light can pass. Examples of such components are cover glasses and / or lens elements, but also carriers of other components, such as mirrors and glass fibers.
    Cover glasses are preferably used to protect electronic components. These naturally also include optoelectronic components.
    The cover glasses are usually in the form of glass plates with plane-parallel surfaces and are preferably attached above the electronic component so that it is protected from environmental influences, but electromagnetic radiation such as light can pass through the cover glass and interact with the electronic component can. Examples of such cover glasses are inside optocaps, to protect electronic image sensors, cover wafers in wafer level packaging, cover glasses for photovoltaic cells and protective glasses for organic electronics. Further applications of cover glasses are sufficiently known to those skilled in the art. It is also possible for optical functions to be integrated into the cover glass, for example if it is provided with optical structures at least in areas which can preferably have the shape of lenses. Cover glasses provided with microlenses are usually used as cover glasses for image sensors in digital cameras, the microlenses usually focusing light incident on the image sensor at an angle onto the individual sensor elements (pixels). It is of course also possible to use the glass according to the invention as substrate glass for electronic components, in which case the electronic components are embedded in the substrate track and / or applied to it.
    On account of its optical properties, the glass according to the invention can also be used for optical applications. Since it is largely chemically inert, it is suitable for applications as substrate and / or cover glass in photovoltaics, for example for covering silicon-based photovoltaic cells, organic photovoltaic cells and / or as a carrier material for thin-film photovoltaic modules. The X-ray absorption of the glass according to the invention has, inter alia, particular advantages when using photovoltaic modules in space applications, since these can be exposed to particularly intense X-rays outside the earth's atmosphere. The property of high X-ray absorption also allows it to be used in general as X-ray protective glass.
    As a cover and / or substrate glass for OLEDs, the glass according to the invention also has an excellent field of application due to its properties.
    The glass according to the invention is also suitable for use as a cover and / or substrate glass for biochemical applications, in particular for molecular screening processes.
    On account of its high temperature resistance, the glass according to the invention is also suitable as lamp glass, in particular for use in halogen lamps and / or fluorescent tubes and their related designs. If the mechanisms of light generation in the lamp generate X-rays, it is a particular advantage of the glass according to the invention that it can keep it away from the environment.
    The invention also includes evaporating the glass according to the invention by physical methods and depositing the evaporated glass on components. Such physical vapor deposition processes, also called physical vapor deposition or PVD processes for short, are known to the person skilled in the art and are described, for example, in DE 10 222 964 B4. The glass according to the invention serves as a target to be evaporated in such processes. The components vapor-coated with the glass according to the invention can benefit both from the chemical resistance of the glass and from its X-ray absorption.
    It is also possible to use the glass according to the invention as a starting material for glass fibers. The term glass fiber encompasses all types of glass fibers, in particular fibers that consist only of a core, and so-called core-sheath fibers, which have a core and at least one sheath preferably completely surrounding the core along the outer circumferential surface. The glass according to the invention can be used as core glass and / or as cladding glass. Within the composition range of the glass according to the invention, the refractive index nd of the glass can be set so that a core glass according to the invention has a higher refractive index than a cladding glass according to the invention, so that a so-called step index fiber is obtained in which the light conduction is very efficient by total reflection at the interface between core and Coat is done. The term also includes side-emitting fibers as described, for example, in WO 2009/100 834 A1.
    In addition, because of their high resistance, the glasses according to the invention are also suitable as matrix material for the safe intermediate and / or final storage of radioactive waste, and for embedding radioactive materials.
    This glass also shows advantages when used as container glass or packaging for pharmaceutical products. Due to the high resistance to the surrounding media, interactions with ingredients can be almost excluded.
    Due to its good chemical resistance, the use of the glass fibers according to the invention as reinforcements in composite materials and / or as concrete reinforcements and / or as optical fibers embedded in concrete also lends itself as a field of application.
    Table 1 includes exemplary embodiments in the preferred composition range. All information regarding the composition is given in% by weight.
    All values of the ALGWD were determined on the basis of DIN ISO 4049, but using a digital X-ray device. The gray values obtained in this way were measured using image processing software and the X-ray absorption was determined from this.
    The glasses described in the examples were produced as follows:
    The raw materials for the oxides are weighed without refining agents and then mixed well. The glass batch is melted in a discontinuous melting unit at around 1580 ° C, then refined and homogenized. At a casting temperature of around 1600 ° C, the glass can be cast and processed as ribbons or other desired dimensions. In a large-volume, continuous unit, the temperatures can be reduced by at least about 100 K.
    For further processing, the cooled glass ribbons were ground to a glass powder with an average particle size of at most 10 μm with the aid of the method known from DE 4 100 604 C1. Glass properties were determined from gobs of glass that were not ground into powders. All glasses have excellent chemical resistance to acids, alkalis, water and fluorine-containing substances such as NaF and NaF / acetic acid.
    In Table 1, the refractive indices nd, the glass transformation temperature Tgs and the linear thermal expansion coefficients α (20-300) from 20 to 300 ° C and α (-30-70) from -30 to 70 ° C are listed. The latter is of particular interest for the use of the glass according to the invention as dental glass, because the temperature range from −30 to 70 ° C. can occur in the application.
    Also listed is the chemical resistance of the variants of the glass according to the invention, which is qualified by the values achieved for the acid, alkali and water resistance. S stands for the acid resistance class according to DIN 12116, L for the alkali resistance class according to DIN ISO 695 and HGB for the water resistance class according to DIN ISO 719.
    In order to further qualify the excellent chemical resistance of the glasses according to the invention, an even more stringent test was carried out, which in particular tests the resistance to fluorine and / or fluorides. The resistance to fluorine-containing components, as they often occur in tooth cleaning materials and serve to fluorinate and / or strengthen healthy tooth material, was tested with the help of an NaF solution and an NaF acetic acid solution as follows: Production of a composite from 50% monomer and 50% silanized glass powder, with an average grain size (d50) of 3 µm, measured by means of laser diffraction (CILAS 1064L device). The specimens are polished on both sides and are exposed for 16 hours at a temperature of 37 ° C. and 100 ° C. in a 0.001 molar NaF solution and a 0.001 molar NaF solution and 4% acetic acid. The surface of the polished samples is examined by means of SEM before and after the resistance test.
    Very good samples showed no changes. Good samples showed only small marginal gaps between the monomer and the glass powder particles. Bad samples showed that the glass particles were leached out of the monomer matrix. Due to the complexity of these tests, the results of this test are not yet available for all variants of the glass according to the invention.
    All glasses listed in Table 1 have coefficients of thermal expansion α (20-300) in the range from 20 to 300 ° C. of less than 7⋅10 <–> <6> K <–> <1> and are within the Measurement limits of the analysis free of BaO.
    Compared with BaO-containing glasses, glasses shown in Table 1 have at least as good a radiopacity. In the examples shown, ALGWD values of 399% to 763% are achieved.
    The examples also demonstrate that the refractive indices nd of the glass system according to the invention can be adapted to the intended use, in particular in a range from 1.53 to 1.56, without the required ALGWD suffering as a result. As a result, it can be used in an advantageous manner, in particular as fillers in dental materials, but also for other applications that have high requirements, among other things. in terms of purity as well as chemical and temperature resistance. It can be manufactured economically on a large scale.
    Compared with the prior art, the glass according to the invention also has the advantage that it combines the adaptability of the refractive indices and expansion coefficients as well as consistently very good chemical stability with efficient X-ray absorption.
    The glass according to the invention is also relatively easy to melt and therefore can be produced efficiently.
    权利要求:
    Claims (18)
    [1]
    1. Radiopaque glass with a refractive index nd of 1.50 to 1.58 and an aluminum equivalent thickness of at least 300% which is free of BaO and PbO except for impurities, including, in% by weight, based on oxide, SiO2 55-75 B2O3 0–9 Al2O3 0.5–4 Li2O 0–2 Na2O 0–7 K2O 0–9 Cs2O 0–15 SrO 4–17 CaO 0–11 MgO 0– <3 ZrO2 1– <11 La2O3 1–10 SnO2 0– 4 Li2O + Na2O + K2O 0.5–12 SrO + Cs2O + La2O3 + SnO2 + ZrO2 ≥ 10
    [2]
    2. Radiopaque glass according to claim 1, containing, in% by weight on the oxide basis, SiO2 56-74 B2O3 0-7 Al2O3 0.5-3.5 Li2O 0-1 Na2O 0-5 K2O 0-8 Cs2O 1-14 SrO 4–16 CaO 0–10 MgO 0– <2 ZrO2 1– <10 La2O3 2–8 SnO2 0–3 Li2O + Na2O + K2O 0.5–11 SrO + Cs2O + La2O3 + SnO2 + ZrO2 ≥ 11
    [3]
    3. Radiopaque glass according to one of the preceding claims 1 or 2, containing, in% by weight based on oxide, SiO2> 59–70 B2O3 0–4 Al2O3 0.5–2 Li2O 0– <1 Na2O 0–3 K2O 0– 6 Cs2O 3–12 SrO 6–14 CaO 0–8 MgO 0– <1 ZrO2 2–9 La2O3 3–6 SnO2 0–3 Li2O + Na2O + K2O 3–9 SrO + Cs2O + La2O3 + SnO2 + ZrO2 ≥ 15
    [4]
    4. Radiopaque glass according to one of the preceding claims 1 to 3, wherein the sum of the proportions of SrO and Cs2O and La2O3 and SnO2 and ZrO2, in% by weight on an oxide basis, is> 18%, preferably> 20%, particularly preferably> 21% .
    [5]
    5. Radiopaque glass according to one of the preceding claims 1 to 4, where the following applies to the ratio of the contents of SiO2 and ZrO2:SiO2 / ZrO2> 6.5, preferably SiO2 / ZrO2> 7.
    [6]
    6. Radiopaque glass according to one of the preceding claims 1 to 5, additionally containing, in% by weight based on oxide, WO3 up to 3 Nb2O5 up to 3 HfO2 up to 3 Ta2O5 up to 5 Sc2O3 up to 3 Y2O3 up to 3 Yb2O3 to 3
    [7]
    7. Radiopaque glass according to one of the preceding claims 1 to 6, which is free of at most traces of B2O3 and / or Li2O and / or fluorides and preferably contains <5%, in% by weight based on oxide, ZnO.
    [8]
    8. Radiopaque glass according to one of the preceding claims 1 to 7 with a coefficient of thermal expansion α (20-300) of less than 7⋅10 <–> <6> <> K <-1>.
    [9]
    9. Radiopaque glass according to one of the preceding claims 1 to 8 with an acid resistance S according to DIN 12116 class 2, edition March 2001, or better, an alkali resistance L according to DIN ISO 695 class 1, edition February 1994, and a water resistance according to HGB DIN ISO 719 class 2, December 1989 edition, or better.
    [10]
    10. Glass consisting of at least 95%, by weight, based on oxide, of the radiopaque glass according to one of the preceding claims 1 to 9.
    [11]
    11. Use of a radiopaque glass according to one of claims 1 to 9 as a glass powder.
    [12]
    12. Use of a glass according to claim 10 as a glass powder.
    [13]
    13. Use of a radiopaque glass according to one of claims 1 to 9 as dental glass, in particular as a filler in composites for tooth restoration.
    [14]
    14. Use of a glass according to claim 10 as dental glass, in particular as a filler in composites for tooth restoration.
    [15]
    15. Use of a radiopaque glass according to one of claims 1 to 9 as a filler or inert aggregate in glass ionomer cements, preferably as an inert aggregate in plastic-reinforced glass ionomer cements.
    [16]
    16. Use of a glass according to claim 10 as a filler or inert aggregate in glass ionomer cements, preferably as an inert aggregate in plastic-reinforced glass ionomer cements.
    [17]
    17. Use of a radiopaque glass according to one of the preceding claims 1 to 9 as a radiopaque in plastic dental materials.
    [18]
    18. Use of a glass according to claim 10 as an X-ray opaquer in plastic dental materials.
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    同族专利:
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    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US4277286A|1980-02-19|1981-07-07|Corning Glass Works|Lead-free glasses of high x-ray absorption for cathode ray tubes|
    DE4100604C1|1991-01-11|1992-02-27|Schott Glaswerke, 6500 Mainz, De|
    US5215944A|1991-07-29|1993-06-01|Ppg Industries, Inc.|X-ray absorbing glass compositions|
    DE69315901T2|1992-07-01|1998-08-27|Proceram|Lead-free, clear, glass-ceramic compositions and articles made from them|
    US5827790A|1993-02-13|1998-10-27|Proceram|Unleaded transparent vitreous glass composition and articles|
    DE4443173C2|1994-12-05|1997-04-10|Schott Glaswerke|Barium-free dental glass with good X-ray absorption|
    DE19725552A1|1997-06-12|1998-12-24|Ivoclar Ag|Alkali silicate glass|
    DE19849388C2|1998-10-27|2001-05-17|Schott Glas|Barium-free x-ray opaque dental glass and its use|
    DE19945517B4|1999-02-15|2005-03-17|Schott Ag|High zirconium oxide containing glass and its uses|
    JP4692915B2|2002-05-29|2011-06-01|日本電気硝子株式会社|Front glass substrate for plasma display devices.|
    DE60315684T2|2003-12-22|2008-06-05|3M Espe Ag|Glass filling material and method of manufacture|
    JP5330754B2|2007-07-27|2013-10-30|株式会社松風|Glass composition and dental composition using the same|
    DE102009008953B4|2009-02-13|2010-12-30|Schott Ag|X-ray opaque barium-free glass and its use|
    DE102009008951B4|2009-02-13|2011-01-20|Schott Ag|X-ray opaque barium-free glass and its use|
    DE102009008954B4|2009-02-13|2010-12-23|Schott Ag|X-ray opaque barium-free glass and its use|
    DE102010007796B3|2010-02-12|2011-04-14|Schott Ag|X-ray opaque barium-free glass and its use|CN104341105B|2013-08-05|2017-04-19|成都光明光电股份有限公司|Near-infrared light absorbing glass, element and light filter|
    ES2875310T3|2014-06-30|2021-11-10|G C Dental Ind Corp|Fluoroaluminosilicate Glass Powder|
    US10301212B2|2016-07-29|2019-05-28|Schott Ag|Radiopaque glass and uses thereof|
    US11136260B2|2016-07-29|2021-10-05|Schott Ag|Radiopaque glass and use thereof|
    JP6896005B2|2018-02-01|2021-06-30|ショット アクチエンゲゼルシャフトＳｃｈｏｔｔ ＡＧ|X-ray opaque glass and its use|
    DE102018102301B4|2018-02-01|2019-08-14|Schott Ag|X-ray opaque glass and its use|
    DE102018010246A1|2018-02-01|2019-08-01|Schott Ag|X-ray opaque glass and its use|
    法律状态:
    2016-10-31| PCAR| Change of the address of the representative|Free format text: NEW ADDRESS: GARTENSTRASSE 28 A, 5400 BADEN (CH) |
    优先权:
    申请号 | 申请日 | 专利标题
    DE102011084501A|DE102011084501B3|2011-10-14|2011-10-14|X-ray opaque barium-free glass and its use|
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