Technical Glasses Physical and Technical Properties 2 SCHOTT is an international technology group with 130 years of ex­ perience in the areas of specialty glasses and materials and advanced technologies. With our high­quality products and intelligent solutions, we contribute to our customers’ success and make SCHOTT part of everyone’s life. For 130 years, SCHOTT has been shaping the future of glass technol­ ogy. The Otto Schott Research Center in Mainz is one of the world’s leading glass research institutions. With our development center in Duryea, Pennsylvania (USA), and technical support centers in Asia, North America and Europe, we are present in close proximity to our customers around the globe. 3 Foreword Apart from its application in optics, glass as a technical ma­ SCHOTT Technical Glasses offers pertinent information in terial has exerted a formative influence on the development concise form. It contains general information for the deter­ of important technological fields such as chemistry, pharma­ mination and evaluation of important glass properties and ceutics, automotive, optics, optoelectronics and information also informs about specific chemical and physical character­ technology. Traditional areas of technical application for istics and possible applications of the commercial technical glass, such as laboratory apparatuses, flat panel displays and glasses produced by SCHOTT. With this brochure, we hope light sources with their various requirements on chemical­ to assist scientists, engineers, and designers in making the physical properties, have led to the development of a great appropriate choice and make optimum use of SCHOTT variety of special glass types. Through new fields of appli­ products. cation, particularly in optoelectronics, this variety of glass types and their modes of application have been continually Users should keep in mind that the curves or sets of curves enhanced, and new forming processes have been devel­ shown in the diagrams are not based on precision measure­ oped. The hermetic encapsulation of electronic components ments but rather characterize and illustrate the typical has given decisive impetus to development activities. Finally, property profiles of the respective glasses or glass types. the manufacture of high­quality glass­ceramics from glass Up­to­date characteristic values of particular glasses can has opened entirely new dimensions, setting new standards be found in the tables of this brochure or in separate data for various technical applications. sheets. To continuously optimize all commercial glasses and glass articles for existing applications and develop glasses and Mainz, January 2014 processes for new applications is the constant endeavor of SCHOTT. For such dynamic development, it is essential to be in close contact with the customers and to keep them as well informed as possible about glass. 4 Contents 1. Types of Technical Glasses ....................................... 6 Basic physical & chemical properties of specialty glass 2. Chemical Stability / Resistance of Glasses .................... 8 2.1 Chemical reaction mechanisms with water, acids, and alkaline solutions .............................................. 8 2.2 Determination of chemical stability ................................. 9 2.3 The significance of chemical stability. 12 3. Mechanical and Thermal Properties .........................14 3.1 Viscosity .......................................................... 14 3.2 Strength .......................................................... 15 3.3 Elasticity .......................................................... 17 3.4 Coefficient of linear thermal expansion ............................ 17 4. Electrical Properties ............................................. 20 4.1 Volume resistivity ................................................. 20 4.2 Surface resistivity ................................................. 21 4.3 Dielectric properties ............................................... 21 4.4 Dielectric strength ................................................ 23 5. Optical Properties ............................................... 24 5.1 Refraction of light ................................................. 24 5.2 Reflection of light ................................................. 24 5.3 Transmittance ..................................................... 25 5.4 Color of glass ..................................................... 27 5.5 Stress birefringence ............................................... 27 Application of specialty glass in select fields 6. Highly Resistant Glasses for Laboratory, Pharma and ... ................................................... 28 6.1 DURAN® .......................................................... 28 6.2 FIOLAX® .......................................................... 29 6.3 BOROFLOAT® 33/SUPREMAX® ..................................... 31 7. Flat Glasses for Home Appliances, Architecture and Safety ........................................ 32 7.1 AMIRAN® ......................................................... 33 7.2 MIRONA® ......................................................... 33 7.3 MIROGARD®. 33 5 7.4 PYRAN®, PYRANOVA®, NOVOLAY® secure & PYRANOVA® secure .... 33 7.5 Processed flat glass for home appliances ........................... 34 7.6 Special solutions for home appliances ............................. 34 7.7 Insulated glass doors for commercial refrigeration .................. 35 7.8 Radiation shielding glasses ........................................ 35 8. Thin Glasses / Ultra­Thin Glasses for Electronics and More .......................................................... 36 8.1 BOROFLOAT® 33 .................................................. 36 8.2 Xensation® Cover ................................................. 36 8.3 Thin glasses. 36 8.4 Thin glass processing .............................................. 38 8.5 Anti­reflective glasses for technical applications (CONTURAN®/DARO) ............................................. 40 9. Glasses for Joinings .............................................. 44 9.1 Sealing glasses ................................................... 44 9.2 Glass and glass­ceramic sealants for technical ceramics ............. 51 9.3 Glass and glass­ceramic sealants for solid oxide fuel cells (SOFC) / sold elecholyzer cells / SO EC ...................................... 52 9.4 Solder glasses ..................................................... 53 9.5 Passivation glasses ................................................ 56 10. Glass­Ceramics for Industrial Applications and Home Appliances .......................................... 58 10.1 Introduction to glass­ceramics ..................................... 58 10.2 PYRAN® Platinum ................................................. 60 10.3 ZERODUR® ........................................................ 60 10.4 NEXTREMA™ ..................................................... 60 11 Optical Materials ................................................. 62 11.1 Introduction of Advanced Optics .................................. 62 11.2 Product overview ................................................. 62 Appendix Glass Types ............................................................. 66 Glasses for the Chemical Industry and Electrical Engineering – Sealing Glasses ......................... 68 Your Contacts .......................................................... 73 Literature ................................................................ 74 6 1. Types of Technical Glasses In the following, technical glasses are understood to be spe­ Other typical applications for different forms of borosilicate cial glasses manufactured in the form of tubes, rods, hollow glass include glass tubing, glass piping, glass con tainers, vessels and a variety of special shapes, as well as flat glass etc. especially for the chemical industry. and glass powder for use mainly in chemistry, lab oratory technology, pharmaceuticals, optoelectronics, and house­ BOROFLOAT® 33, SUPREMAX® and DURAN® belong to this hold appliance technology. glass family. Glasses for purely optical applications are usually distin­ Alkaline earth containing borosilicate glasses guished from these technical glasses by their special manu­ In addition to about 75 % SiO2 and 8 – 12 % B2O3, these facturing processes and by their special compositional glasses contain up to 5 % alkaline earths and alumina ranges. (Al2O3). To this subtype of slightly softer glasses (as com­ pared with non­alkaline earth borosilicate glass), which For the purposes of classification, the multitude of technical have thermal expansion of between 4.0 – 5.0 x 10–6/K, be­ glasses can be roughly arranged in the following six groups, long the chemically highly resistant varieties FIOLAX® 8412 according to their oxide composition (in weight percent). It and 8414 (“neutral glasses”), and SUPRAX® and 8488. should be noted, however, that certain glasses fall between these groups, and others completely outside of the groups, High-borate borosilicate glasses and therefore cannot be classified as belonging to these Glasses containing 15 – 25 % B2O3, 65 – 70 % SiO2, and smaller types. amounts of alkalis and Al2O3 as additional components, have low softening points and low thermal expansion. Sealability to metals in the expansion range of tungsten­molybdenum Borosilicate glasses and high electrical insulation are their most important fea­ tures. The increased B2O3 content reduces the chemical resis­ Characteristic of this