Glass for magnetic recording medium substrate, magnetic recording medium substrate, magnetic recording medium and glass spacer for magnetic recording and reproducing apparatus
US-2024321310-A1 · Sep 26, 2024 · US
Non-alkali glass, and process for production of non-alkali glass
US9108879B2 · US · B2
| Field | Value |
|---|---|
| Publication number | US-9108879-B2 |
| Application number | US-201313928617-A |
| Country | US |
| Kind code | B2 |
| Filing date | Jun 27, 2013 |
| Priority date | Dec 27, 2010 |
| Publication date | Aug 18, 2015 |
| Grant date | Aug 18, 2015 |
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Abstract
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The present invention relates to an alkali-free glass having a strain point of 735° C. or higher, an average thermal expansion coefficient at from 50 to 350° C. of from 30×10 −7 to 40×10 −7 /° C., a temperature T 2 at which a glass viscosity is 10 2 dPa·s of 1,710° C. or lower, a temperature T 4 at which a glass viscosity is 10 4 dPa·s of 1,340° C. or lower, and a devitrification temperature of 1,330° C. or lower, the alkali-free glass including, in terms of mol % on the basis of oxides: SiO 2 66 to 69, Al 2 O 3 12 to 15, B 2 O 3 0 to 1.5, MgO 6 to 9.5, CaO 7 to 9, SrO 0.5 to 3, BaO 0 to 1, and ZrO 2 0 to 2, in which MgO+CaO+SrO+BaO is from 16 to 18.2, MgO/(MgO+CaO+SrO+BaO) is 0.35 or more, MgO/(MgO+CaO) is 0.40 or more and less than 0.52, and MgO/(MgO+SrO) is 0.45 or more.
First claim
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The invention claimed is: 1. An alkali-free glass comprising, in terms of mol % on the basis of oxides: SiO 2 66 to 69, Al 2 O 3 12 to 15,…
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- What does patent US9108879B2 cover?
- The present invention relates to an alkali-free glass having a strain point of 735° C. or higher, an average thermal expansion coefficient at from 50 to 350° C. of from 30×10 −7 to 40×10 −7 /° C., a temperature T 2 at which a glass viscosity is 10 2 dPa·s of 1,710° C. or lower, a temperature T 4 at which a glass viscosity is 10 4 dPa·s of 1,340° C. or lower, and a devitrification temperatu…
- Who is the assignee on this patent?
- Asahi Glass Co Ltd
- What technology area does this patent fall under?
- Primary CPC classification C03C3/087. Mapped technology areas include Chemistry & Metallurgy.
- When was this patent published?
- Publication date Tue Aug 18 2015 00:00:00 GMT+0000 (Coordinated Universal Time) (B2). Legal status and post-grant events are not shown on this page.
- What related patents are in patentsdb?
- We list 8 related publications on this page (citations in our corpus or others sharing the same primary CPC).