Color cathode ray tube and glass frit for color cathode ray tubes
First Claim
1. A color cathode ray tube having a sealed portion at which a glass panel and a glass funnel are sealed by means of a sintered glass frit, whereina maximum tensile stress generated at the sealed portion is from 7 to 10 MPa when an inside of said color cathode ray tube is vacuumized, the sintered glass frit contains at least a low expansion filler containing α
- -alumina and a crystalline low melting glass, and an area ratio of crystal is at least 50% at an interface at the sealed portion at at least a region at which the maximum tensile stress is generated.
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Abstract
The present invention relates to a color cathode ray tube and a glass frit to be used for it, and provides a color cathode ray tube which uses a glass frit containing as a crystallizing filler, an α-4PbO.B2O3 crystal powder and/or a Pb3O4 crystal powder, and corpuscular α-alumina, and at least one member selected from the group consisting of MgO, Fe2O3 and monoclinic ZrO2, for improvement of the strength at a sealed portion and for weight saving of the color cathode ray tube, wherein the maximum tensile stress generated at the above sealed portion is from 7 to 10 MPa when the inside is vacuumized, and the area ratio of crystal is at least 50% at the interface at the above sealed portion at at least the region at which the above maximum tensile stress is generated.
19 Citations
15 Claims
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1. A color cathode ray tube having a sealed portion at which a glass panel and a glass funnel are sealed by means of a sintered glass frit, wherein
a maximum tensile stress generated at the sealed portion is from 7 to 10 MPa when an inside of said color cathode ray tube is vacuumized, the sintered glass frit contains at least a low expansion filler containing α - -alumina and a crystalline low melting glass, and
an area ratio of crystal is at least 50% at an interface at the sealed portion at at least a region at which the maximum tensile stress is generated. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
crystalline low melting glass;
90-99%,low expansion filler;
1-10%,and content of the α
-alumina is from 0.1 to 7% based on the sintered glass frit.
- -alumina and a crystalline low melting glass, and
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3. The color cathode ray tube according to claim 2, wherein part of particles of the α
- -alumina is corpuscular α
-alumina having a particle size not larger than 3 μ
m, and a content of the corpuscular α
-alumina is from 0.1 to 5% represented by mass percentage based on the sintered glass frit.
- -alumina is corpuscular α
-
4. The color cathode ray tube according to claim 2, wherein the crystalline low-melting glass consists essentially of, represented by mass percentage based on following oxides:
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5. The color cathode ray tube according to claim 1, wherein the sintered glass frit contains a low expansion filler containing α
- -alumina, a crystalline low melting glass and a crystallizing filler containing MgO and/or Fe2O3, and contents of the above respective components represented by mass percentage based on the sintered glass frit are as follows;
crystalline low melting glass;
90-98.9%,low expansion filler;
1-9.9%,and a content of the α
-alumina is from 0.1 to 7% based on the sintered glass frit.
- -alumina, a crystalline low melting glass and a crystallizing filler containing MgO and/or Fe2O3, and contents of the above respective components represented by mass percentage based on the sintered glass frit are as follows;
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6. The color cathode ray tube according to claim 5, wherein a sum of masses of the MgO and Fe2O3 is from 0.1 to 5% represented by mass percentage based on the sintered glass frit.
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7. The color cathode ray tube according to claim 1, wherein the above sintered glass frit contains a low expansion filler containing α
- -alumina, a crystalline low melting glass and monoclinic-ZrO2 as a crystallizing filler, and contents of the respective components represented by mass percentage based on the sintered glass frit are as follows;
crystalline low melting glass;
90-98.99%,low expansion filler;
1-9.99%,and a content of the α
-alumina is from 0.1 to 7% based on the sintered glass frit.
- -alumina, a crystalline low melting glass and monoclinic-ZrO2 as a crystallizing filler, and contents of the respective components represented by mass percentage based on the sintered glass frit are as follows;
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8. The color cathode ray tube according to claim 7, wherein a content of the monoclinic-ZrO2 is from 0.01 to 1% represented by mass percentage based on the sintered glass frit.
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9. The color cathode ray tube according to claim 1, wherein the low expansion filler contains at least one member selected from a group consisting of zircon, cordierite, mullite, lead titanate, silica, β
- -eucryptite, β
-spodumene and β
-quartz solid solution.
- -eucryptite, β
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10. A glass frit, for color cathode ray tubes, which comprises
a crystalline low melting glass powder, a low expansion filler containing α - -alumina, and
a crystallizing filler consisting of an α
-4PbO.B2O3 crystal powder and/or a Pb3O4 crystal powder,wherein part of the α
-alumina is corpuscular α
-alumina having a particle size not larger than 3 μ
m, andcontents of the above respective components represented by mass percentage based on said glass frit are as follows;
crystalline low melting glass powder;
90-99%,low expansion filler;
1-10%,and a content of the α
-alumina is from 0.1 to 7% based on a sintered glass frit, anda content of the corpuscular α
-alumina of the α
-alumina is from 0.1 to 5% based on the sintered glass frit.- View Dependent Claims (11, 12)
- -alumina, and
-
12. The glass frit for color cathode ray tubes according to claim 10, wherein the low expansion filler contains at least one member selected from a group consisting of zircon, cordierite, mullite, lead titanate, silica, β
- -eucryptite, β
-spodumene and β
-quartz solid solution.
- -eucryptite, β
-
13. A glass frit for color cathode ray tubes, which comprises
a crystalline low melting glass powder, a low expansion filler containing α - -alumina, and
a crystallizing filler containing at least one member selected from a group consisting of an α
-4PbO.B2O3 crystal powder and/or a Pb3O4 crystal powder, MgO, Fe2O3 and monoclinic-ZrO2,wherein contents of the respective components represented by mass percentage based on the glass frit are as follows;
crystalline low melting glass powder;
90-98.99%,low expansion filler;
1-9.99%,crystallizing filler;
0.01-5%,and a content of the α
-alumina is from 0.1 to 7% based on the glass frit.- View Dependent Claims (14, 15)
- -alumina, and
-
15. The glass frit for color cathode ray tubes according to claim 13, wherein the low expansion filler contains at least one member selected from a group consisting of zircon, cordierite, mullite, lead titanate, silica, β
- -eucryptite, β
-spodumene and β
-quartz solid solution.
- -eucryptite, β
Specification