Non-alkali glass
View Patent ↗Provided is a non-alkali glass having a strain point of 680° C. or higher, having an average thermal expansion coefficient of from 30×10 −7 /° C. to 45×10 −7 /° C. at from 50° C. to 350° C., containing, indicated by mass % on the basis of oxides: SiO 2 : 54% to 66%, Al 2 O 3 : 10% to 27%, B 2 O 3 : 0.2% to 5.5%, MgO: 0% to 10%, CaO: 0% to 15%, SrO: 0% to 15%, BaO: 0% to 15%, and MgO+CaO+SrO+BaO: 8% to 25%, containing 600 mass ppm or less of Na 2 O, and satisfying a mass ratio (Na 2 O/B 2 O 3 ) between Na 2 O and B 2 O 3 being from 0.001 to 0.3.
1. A non-alkali glass having a strain point of 680° C. or higher, having an average the thermal expansion coefficient of from 30×10 −7 /° C. to 43×10 −7 /° C. at from 50° C. to 350° C., comprising, indicated by mass % on the basis of oxides:
SiO 2 : 54% to 66%,
Al 2 O 3 : 10% to 27%,
B 2 O 3 : 0.2% to 5.5%,
MgO: 0% to 10%,
CaO: 0% to 15%,
SrO: 0% to 15%,
BaO: 0% to 15%, and
MgO+CaO+SrO+BaO: 8% to 25%,
comprising 600 mass ppm or less of Na 2 O, and
satisfying a mass ratio (Na 2 O/B 2 O 3 ) between Na 2 O and B 2 O 3 being from 0.001 to 0.3.
2. The non-alkali glass according to claim 1 , having a denitrification viscous property η satisfying log η=3.5 [dPa·s] or more, comprising, indicated by mass % on the basis of oxides:
SiO 2 : 57% to 63%,
Al 2 O 3 : 18% to 23%,
B 2 O 3 : 0.2% to 5.5%,
MgO: 1% to 8.5%,
CaO: 3% to 12%,
SrO: 0% to 10%,
BaO: 0% to 5%, and
MgO+CaO+SrO+BaO: 13% to 23%, and
satisfying:
MgO/(MgO+CaO+SrO+BaO) being 0.15 or more,
CaO/(MgO+CaO+SrO+BaO) being 0.60 or less,
SrO/(MgO+CaO+SrO+BaO) being 0.70 or less, and
BaO/(MgO+CaO+SrO+BaO) being 0.50 or less.
3. The non-alkali glass according to claim 1 , having a devitrification viscous property η satisfying log η=4.5 [dPa·s] or more, comprising, indicated by mass % on the basis of oxides:
SiO 2 : 58% to 65%,
Al 2 O 3 : 14% to 22%,
B 2 O 3 : 0.2% to 5.5%,
MgO: 0% to 6%,
CaO: 3% to 12%,
SrO: 0% to 10%,
BaO: 0% to 10%, and
MgO+CaO+SrO+BaO: 8% to 22%, and
satisfying:
MgO/(MgO+CaO+SrO+BaO) being 0.25 or less,
CaO/(MgO±CaO+SrO+BaO) being 0.20 or more,
SrO/(MgO+CaO+SrO+BaO) being 0.50 or less, and
BaO/(MgO±CaO+SrO+BaO) being 0.70 or less.
4. The non-alkali glass according to claim 1 , wherein the mass ratio (Na 2 O/B 2 O 3 ) between Na 2 O and B 2 O 3 is 0.001 or more and less than 0.06.
5. The non-alkali glass according to claim 1 , having a strain point of 680° C. to 780° C.
6. The non-alkali glass according to claim 1 , having a strain point of 690° C. to 730° C.
7. The non-alkali glass according to claim 1 , having an average thermal expansion coefficient of from 35×10 −7 /° C. to 40×10 −7 /° C.
8. The non-alkali glass according to claim 1 , having a thermal shrinkage rate of 90 ppm or less.
9. The non-alkali glass according to claim 1 , obtained by cooling at an equivalent cooling rate of 400° C./minute or less.
10. A thin film transistor, comprising the non-alkali glass according to claim 1 .
11. A thin film transistor, comprising the non-alkali glass according to claim 2 .
12. A thin film transistor, comprising the non-alkali glass according to claim 3 .
13. A thin film transistor, comprising the non-alkali glass according to claim 8 .
14. A thin film transistor, comprising the non-alkali glass according to claim 9 .
15. A thin film transistor, comprising the non-alkali glass according to claim 4 .
16. A thin film transistor, comprising the non-alkali glass according to claim 5 .
17. A thin film transistor, comprising the non-alkali glass according to claim 6 .
18. A thin film transistor, comprising the non-alkali glass according to claim 7 .