[0115] The present invention relates to glasses that are resistant in several respects. Particularly resistant glass is especially useful when the glass is exposed to special requirements. This is the case in extreme environments, for example. Extreme environments are especially application areas that require special resistance, durability and safety, such as areas that require explosion protection.
[0116] In one embodiment, the present invention relates to glass articles having particular suitability for use in extreme environments and having the following properties:
[0117] - The induced extinction α(λ) at 200 nm does not exceed 0.300 after 48 hours of irradiation with a deuterium lamp,
[0118] - The induced extinction α(λ) at 254 nm does not exceed 0.100 after 48 hours of irradiation with a deuterium lamp,
[0119] - a thickness of at least 0.3 mm, in particular at least 3 mm and/or at most 20 mm, and/or
[0120] - Thermal shrinkage is less than 50μm/100mm.
[0121] In extreme environments, it may be useful to provide glass articles with a specific minimum thickness because thicker glass is mechanically more stable than thinner glass. However, thicker glass absorbs most of the UV radiation entering the glass, resulting in heat generation. In environments with highly flammable materials, the generation of high heat can be problematic. Glass articles with low induced extinction at 200 nm and/or 254 nm offer the advantage of maintaining high transmission for the wavelengths considered, even after prolonged use, and avoiding excessive heat generation.
[0122] According to the present invention, glass articles can also be used in UV lamps for sterilizing surfaces in extreme environments. In one embodiment, the glass article is used in a UV lamp (especially as a cover) for sterilizing the site of action. The site of action can be an object that many people touch, such as a handle, especially a doorknob. For example, the UV lamp can be positioned in such a way that it can apply UV radiation to the site of action. In this case, a certain distance from the site of action cannot be avoided. Therefore, there is a risk here that the glass article will be damaged by impact. This leads to the need for mechanical resistance. Mechanical resistance can be improved by greater thickness of the glass article, however, this reduces the transmittance of the article and greatly increases the heat of the glass during UV lamp operation. Excessive heat should be avoided, which in turn is positively affected by very good transmission and low induced extinction. Excessive temperature affects safety due to the risk of burns or explosion to the user. In principle, the risk of burns can be reduced by greater distances, but this has to be compensated for by greater radiation intensity, with the disadvantage of generating more heat.
[0123] The invention also relates to a UV lamp and the use of glass articles in UV lamps for disinfection, especially in extreme environments, especially for disinfection of areas of action, such as those touched by many people. It has proven advantageous to keep a minimum distance of 5 cm, in particular 7.5 cm or 10 cm, between the surface to be sterilized and the glassware. When using the glass articles described herein, at least 1.0 mW/cm may be provided at the site of action 2 , at least 1.5mW/cm 2 , at least 2.5mW/cm 2 , at least 3.0mW/cm 2 or at least 3.5mW/cm 2 energy density. The site of action is the surface to be disinfected. Optionally, the energy density is at most 20 mW/cm 2 , up to 15mW/cm 2 or up to 10mW/cm 2. In particular, energy density is the energy of UV radiation, in particular UV-C radiation, mediated by a UV lamp, which can be measured at the site of action. Preferably, the site of action is periodically sterilized. This means that the site of action is not irradiated continuously but intermittently. For example, an illumination interval can be triggered by a user's touch, presence or actuation. For example, the irradiation interval can be at least 1 second, at least 5 seconds, at least 10 seconds, or at least 20 seconds. Optionally, the irradiation interval lasts up to 10 minutes, up to 5 minutes, up to 2 minutes, or up to 1 minute.
[0124]In one embodiment, the UV lamp and/or the glass article has a thermally optimized structure, wherein the thickness of the glass article and the UV transmittance of the glass article are selected in such a way that when the active site is far away from the glass article (positioned relative to the light source) On the other side of the article) 70mm with a medium pressure mercury lamp at 120W/cm and an arc length of 4cm (eg Philips HOK 4/120) at 17.27mW/cm 2 The UVC energy density of the UVC was continuously irradiated for 5 seconds at an ambient temperature of 20 °C, and the temperature at the surface of the glass product facing the action site did not exceed 45 °C. In one embodiment, the radiation passes vertically through the glass article, ie light enters the glass article substantially perpendicular to the surface facing the light source and/or light exits the glass article substantially perpendicular to the surface of the glass article facing the active site. In particular, the temperature does not exceed a value of 42.5°C, 40°C or 37.5°C. In one embodiment, the temperature limit is not exceeded even after 10 seconds, 20 seconds, 30 seconds, 45 seconds, 60 seconds, 90 seconds, 120 seconds, 150 seconds, or 180 seconds of irradiation. This property describes how strongly a glass article is heated when irradiated vertically with a common UV light source. It is achieved that a UV lamp with a lampshade made of glass is not dangerously heated. UVC energy density refers to the energy density imparted by radiation in the UVC range (280 to 200 nm). Medium pressure mercury lamps also emit light at other wavelengths, which are not taken into account when considering UVC energy density here. Measurements are carried out in ambient atmosphere. For clarity: the properties described do not limit the application of UV lamps or glass articles to medium pressure mercury lamps.
[0125] In one embodiment, the glass article meets the requirements for fracture mode according to DIN EN 12150-1:2020-07. The entire article or a portion of the article may be inspected; for deviations from the specified standard, the article may be less than the standard specified here, so long as the area to be considered is exceeded. The area to be considered for the rupture mode may in particular be 40mm x 40mm or 25mm x 25mm. In one embodiment, under the above conditions, the glass article is broken into not less than 25 pieces, especially not less than 30 pieces or not less than 40 pieces. Breaking the item into many pieces is advantageous because in the case of breakage, the risk of injury is low if the pieces are small. For example, the fracture mode can be influenced by selection of glass composition, cooling conditions (thermal shrinkage), by adjusting the stress in the glass, and/or by strengthening the article.
[0126] In one embodiment, the present invention relates to a glass article made of glass having
[0127] - the segregation factor related to its resistance to hydrolysis is between 0.10 and 1.65,
[0128] - The induced extinction α(λ) at 200 nm does not exceed 0.300 after 48 hours of irradiation with a deuterium lamp,
[0129] - The induced extinction α(λ) at 254 nm does not exceed 0.100 after 48 hours of irradiation with a deuterium lamp,
[0130] - a thickness of at least 0.3 mm, in particular at least 3 mm and/or at most 20 mm, and
[0131] - Thermal shrinkage is less than 50μm/100mm.
[0132] In one embodiment, the present invention relates to a glass article made of glass having
[0133] - the segregation factor related to its resistance to hydrolysis is between 0.10 and 1.65,
[0134] - a thickness of at least 0.3 mm, in particular at least 3 mm and/or at most 20 mm, and
[0135] - The compressive stress on at least one surface is at least 50 MPa.
[0136] In one embodiment, the present invention relates to a glass article made of glass having
[0137] - the segregation factor related to its resistance to hydrolysis is between 0.10 and 1.65,
[0138] - a thickness of at least 0.3 mm, in particular at least 3 mm and/or at most 20 mm, and
[0139] - The compressive stress on at least one surface is at least 50 MPa, and the rupture mode is characterized by a rupture of not less than 25 pieces over an area of 40 mm x 40 mm.
[0140] Example
[0141] Tables 1-4 show exemplary glass compositions and further glass properties in mol%.
[0142] Table 1
[0143]
[0144]
[0145] Table 2
[0146]
[0147]
[0148] table 3
[0149]
[0150]
[0151] Table 4
[0152]
[0153]
[0154] Table 5 below shows the segregation factors for some of the glasses listed here.
[0155] table 5
[0156] 1 17 20 21 22 B 2 O 3 /BaO
[0157] Table 6 below shows the light fastness (induced extinction) of the glass at 200 nm and 254 nm after irradiation with a deuterium lamp for 48 hours and 96 hours. The transmittance of glass in the thickness range of 0.70 to 0.75 mm was measured.
[0158] Table 6
[0159] induced extinction 1 15 19 20 22 24 200nm, 48h 0.070 0.129 0.053 0.031 0.022 0.018 200nm, 96h 0.154 0.180 0.095 0.031 0.030 0.038 254nm, 48h 0.025 0.039 0.015 0.008 0.008 0.006 254nm, 96h 0.062 0.063 0.032 0.010 0.013 0.007
[0160] Table 7 below shows the overall transmittance values for some glasses after 48 hours and 96 hours of irradiation with a deuterium lamp.
[0161] Table 7
[0162] Transmittance[%] 1 18 19 20 22 24 200nm, 48h 63.5 53.7 65.8 67.4 68.5 66.4 200nm, 96h 58.4 54.7 63.1 67.4 67.9 65.1 254nm, 48h 85.4 82.0 87.4 86.8 87.4 86.9 254nm, 96h 82.3 81.8 85.9 86.6 87.0 86.8
[0163] Tables 8 and 9 below show the fusion stresses obtained after fusion of glass articles with glass or metal alloys (Kovar). The CTE of the glass was 5.0 ppm/K; the CTE of the metal alloy was 5.4 ppm/K.
[0164] Table 8
[0165] Weld stress 1 15 16 17 18 19 Glass, 5.0ppm/K[nm/cm] 124 158 119 153 173 225 Kovar, 5.4ppm/K[nm/cm] -261 -221 -177 -194 -229 -342
[0166] Table 9
[0167] Weld stress 20 21 22 23 24 Glass, 5.0ppm/K[nm/cm] 261 109 103 211 146 Kovar, 5.4ppm/K[nm/cm] -370 -229 -224 -316 -266
