Glass ceramic material for plasma display
There is provided a glass ceramic material for plasma display, in which glass fine grains (A) having a softening point of 570-640° C. are in 40-70 wt %, and glass fine grains (B) having a softening point of 480-540° C. are in 30-60 wt %, the glass ceramic material for plasma display being characterized in that the glass fine grains (A) comprise 2-12 wt % of SiO 2 , 50-58 wt % of B 2 O 3 , 10-20 wt % of Al 2 O 3 , 0-6 wt % of ZnO, 0-2.8 wt % of Li 2 O, and 10-22 wt % of at least one selected from MgO, CaO, SrO and BaO and that refractive index of the glass fine grains (A) is 1.53-1.56.
1. A glass ceramic material for plasma display, comprising:
40-70 wt % of glass fine grains (A) having a softening point of 570-640° C., and
30-60 wt % of glass fine grains (B) having a softening point of 480-540° C.
wherein the glass fine grains (A) comprise 2-12 wt % of SiO 2 , 50-58 wt % of B 2 O 3 , 10-20 wt % of Al 2 O 3 , 0-6 wt % of ZnO, 0-2.8 wt % of Li 2 O, and 10-22 wt % of at least one selected from MgO, CaO, SrO and BaO, and
wherein refractive index of the glass fine grains (A) is 1.53-1.56.
2. A glass ceramic material for plasma display according to claim 1 , wherein thermal expansion coefficient of the glass fine grains (A) in 30° C.-300° C. is 50×10 −7 /° C. to 70×10 −7 /° C.
3. A glass ceramic material for plasma display according to claim 1 , wherein the glass fine grains (B) comprise 0-9 wt % of SiO 2 , 50-55 wt % of B 2 O 3 , 0-11 wt % of Al 2 O 3 , 0-12 wt % of ZnO, 21-25 wt % of R 2 0 (Li 2 O+Na 2 O+K 2 O), 0-10 wt % of P 2 O 5 , 0-3 wt % of ZrO 2 , and 5-17 wt % of at least one selected from MgO, CaO, SrO and BaO, and wherein refractive index of the glass fine grains (B) is 1.53-1.56.
4. A glass ceramic material for plasma display according to claim 1 , wherein thermal expansion coefficient of the glass fine grains (B) in 30° C.-300° C. is 95×10 −7 /° C. to 115×10 −7 /° C.
5. A glass ceramic material for plasma display according to claim 1 , wherein a lowest baking temperature [T1], at which a compact sintered body of the glass ceramic material can be obtained, is 500-560° C., and [T1] and a temperature [T2], at which a sintered body of the glass ceramic material starts to soften and flow satisfy a formula of T2−T≧40.
6. A back surface substrate for plasma display panel, comprising a glass ceramic material for plasma display according to claim 1 .