NON-ALKALI GLASS

• Main Authors: TOKUNAGA HIROFUMI, ONO KAZUTAKA, AKIYAMA JUN
• Format: Patent
• Language: English; Japanese
• Published: 19.03.2020
• Subjects: CHEMICAL COMPOSITION OF GLASSES, GLAZES, OR VITREOUSENAMELS; CHEMISTRY; DEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH ISMODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THEDEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY,COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g.SWITCHING, GATING, MODULATING OR DEMODULATING; FREQUENCY-CHANGING; GLASS; JOINING GLASS TO GLASS OR OTHER MATERIALS; METALLURGY; MINERAL OR SLAG WOOL; NON-LINEAR OPTICS; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL LOGIC ELEMENTS; OPTICS; PHYSICS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS,MINERALS OR SLAGS; SURFACE TREATMENT OF GLASS; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF

To provide a non-alkali glass which is a glass having a low thermal shrinkage rate, hardly causes problems by BHF, has high productivity, and has a low thermal shrinkage rate.SOLUTION: Provided is a non-alkali glass having a strain point of 680°C. or higher, having an average thermal expansion coefficient of from 30×10to 45×10/°C at from 50 to 350°C, containing, by mass% on the basis of oxides: SiO:54-66%, AlO:10-27%, BO:0.2-5.5%, MgO:0-10%, CaO:0-15%, SrO:0-15%, BaO:0-15%, MgO+CaO+SrO+BaO:8-25%, containing 600 mass ppm or less of NaO, and satisfying a mass ratio (NaO/BO) between NaO and BObeing from 0.001 to 0.3, and not containing YOor LaO.SELECTED DRAWING: None 【課題】低い熱収縮率のガラスにおいて、ＢＨＦによる問題が発生しにくく、生産性がよく、かつ熱収縮率が低い無アルカリガラスの提供。【解決手段】歪点が６８０℃以上であり、５０〜３５０℃での平均熱膨張係数が３０×１０−７〜４５×１０−７／℃であり、酸化物基準の質量％表示で、ＳｉＯ２：５４〜６６％、Ａｌ２Ｏ３：１０〜２７％、Ｂ２Ｏ３：０．２〜５．５％、ＭｇＯ：０〜１０％、ＣａＯ：０〜１５％、ＳｒＯ：０〜１５％、ＢａＯ：０〜１５％、ＭｇＯ＋ＣａＯ＋ＳｒＯ＋ＢａＯ：８〜２５％を含有し、かつ、Ｎａ２Ｏを６００質量ｐｐｍ以下含有し、Ｎａ２ＯとＢ２Ｏ３との質量比（Ｎａ２Ｏ／Ｂ２Ｏ３）が０．００１以上０．３以下であり、Ｙ２Ｏ３およびＬａ２Ｏ３を含有しない無アルカリガラス。【選択図】なし