Patents by Inventor Nobutatsu Yamaoka
Nobutatsu Yamaoka has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 4626395Abstract: A ceramic composition capable of sintering at a sufficiently low temperature to enable the use of a low cost base metal as the electrode material in the fabrication of capacitors. The major ingredient of the composition is expressed as Ba.sub.k-x M.sub.x O.sub.k TiO.sub.2, where M is one or more of magnesium, zinc, strontium, and calcium, and where k, and x are numerals in the ranges of 1.00 to 1.04, and 0.02 to 0.05, respectively. To this major ingredient is added a minor proportion of a mixture of boron oxide and at least one of barium oxide, magnesium oxide, zinc oxide, strontium oxide, and calcium oxide. For the fabrication of coherently bonded bodies of this composition, as for use as the dielectric bodies of capacitors, the moldings of the mixture of the major ingredient and additive in finely divided form are sintered in a reductive or neutral atmosphere and then reheated at a lower temperature in an oxidative atmosphere. The sintering temperature can be so low (typically from 1050.degree. to 1200.Type: GrantFiled: July 9, 1985Date of Patent: December 2, 1986Assignee: Taiyo Yuden Co., Ltd.Inventors: Takeshi Wada, Hiroshi Nakamura, Masami Fukui, Nobutatsu Yamaoka
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Patent number: 4626393Abstract: A ceramic composition capable of sintering at a sufficiently low temperature to enable the use of a low cost base metal as the electrode material in the fabrication of capacitors. The major ingredient of the composition is expressed as Ba.sub.k-x-y M.sub.x L.sub.y O.sub.k TiO.sub.2, where M is at least either of mag-nesium and zinc, L is at least either of strontium and calcium, k, x and y are numerals in the ranges of 1.00 to 1.04, 0.002 to 0.049, and 0.001 to 0.048, respectively, and x+y is a value in the range of 0.02 to 0.05. To this major ingredient is added a minor proportion of a mixture of lithium oxide, silicon dioxide, and, possibly, at least one of barium oxide, calcium oxide, and strontium oxide.Type: GrantFiled: July 9, 1985Date of Patent: December 2, 1986Assignee: Taiyo Yuden Co., Ltd.Inventors: Takeshi Wada, Hiroshi Nakamura, Masami Fukui, Nobutatsu Yamaoka
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Patent number: 4626394Abstract: A ceramic composition capable of sintering at a sufficiently low temperature to enable the use of a low cost base metal as the electrode material in the fabrication of capacitors. The major ingredient of the composition is expressed as Ba.sub.k-x M.sub.x O.sub.k TiO.sub.2, where M is at least either of magnesium and zinc and where k and x are numerals in the ranges of 1.00 to 1.04 and of 0.02 to 0.05, respectively. To this major ingredient is added a minor proportion of a mixture of lithium oxide, silicon dioxide, and, possibly, at least one of barium oxide, calcium oxide, and strontium oxide. For the fabrication of coherently bonded bodies of this composition, as for use as the dilectric bodies of capacitors, the moldings of the mixture of the major ingredient and additive in finely divided form are sintered in a reductive or neutral atmosphere and then reheated at a lower temperature in an oxidative atmosphere. The sintering temperature can be so low (typically from 1050.degree. to 1200.degree. C.Type: GrantFiled: July 9, 1985Date of Patent: December 2, 1986Assignee: Taiyo Yuden Co., Ltd.Inventors: Takeshi Wada, Hiroshi Nakamura, Masami Fukui, Nobutatsu Yamaoka
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Patent number: 4626396Abstract: A ceramic composition capable of sintering at a sufficiently low temperature to enable the use of a low cost base metal as the electrode material in the fabrication of capacitors. The major ingredient of the composition is expressed as Ba.sub.k-x M.sub.x O.sub.k TiO.sub.2, where M is one or more of magnesium, zinc, strontium, and calcium, and where k, and x are numerals in the ranges of 1.00 to 1.04, and 0.02 to 0.05, respectively. To this major ingredient is added a minor proportion of a mixture of boron oxide, silicon dioxide, and, possibly, at least one of barium oxide, magnesium oxide, zinc oxide, strontium oxide, and calcium oxide. For the fabrication of coherently bonded bodies of this composition, as for use as the dielectric bodies of capacitors, the moldings of the mixture of the major ingredient and additive in finely divided from are sintered in a reductive or neutral atmosphere and then reheated at a lower temperature in an oxidative atmosphere.Type: GrantFiled: July 9, 1985Date of Patent: December 2, 1986Assignee: Taiyo Yuden Co., Ltd.Inventors: Takeshi Wada, Hiroshi Nakamura, Masami Fukui, Nobutatsu Yamaoka
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Patent number: 4610968Abstract: A ceramic composition capable of sintering at a sufficiently low temperature to enable the use of a low cost base metal as the electrode material in the fabrication of capacitors. The major ingredient of the composition is expressed as Ba.sub.k-x M.sub.x O.sub.k TiO.sub.2, where M is one or more of magnesium, zinc, strontium, and calcium, and where k, and x are numerals in the ranges of 1.00 to 1.04, and 0.02 to 0.05, respectively. To this major ingredient is added a minor proportion of a mixture of boron oxide and at least one of barium oxide, magnesium oxide, zinc oxide, strontium oxide, and calcium oxide. For the fabrication of coherently bonded bodies of this composition, as for use as the dielectric bodies of capacitors, the moldings of the mixture of the major ingredient and additive in finely divided form are sintered in a reductive or neutral atmosphere and then reheated at a lower temperature in an oxidative atmosphere. The sintering temperature can be so low (typically from 1050.degree. to 1200.Type: GrantFiled: November 30, 1984Date of Patent: September 9, 1986Assignee: Taiyo Yuden Co., Ltd.Inventors: Takeshi Wada, Hiroshi Nakamura, Masami Fukui, Nobutatsu Yamaoka
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Patent number: 4610971Abstract: A ceramic composition capable of sintering at a sufficiently low temperature to enable the use of a low cost base metal as the electrode material in the fabrication of capacitors. The major ingredient of the composition is expressed as Ba.sub.k-x M.sub.x O.sub.k TiO.sub.2, where M is one or more of magnesium, zinc, strontium, and calcium, and where k, and x are numerals in the ranges of 1.00 to 1.04, and 0.02 to 0.05, respectively. To this major ingredient is added a minor proportion of a mixture of boron oxide, silicon dioxide, and, possibly, at least one of barium oxide, magnesium oxide, zinc oxide, strontium oxide, and calcium oxide. For the fabrication of coherently bonded bodies of this composition, as for use as the dielectric bodies of capacitors, the moldings of the mixture of the major ingredient and additive in finely divided form are sintered in a reductive or neutral atmosphere and then reheated at a lower temperature in an oxidative atmosphere.Type: GrantFiled: November 30, 1984Date of Patent: September 9, 1986Assignee: Taiyo Yuden Co., Ltd.Inventors: Takeshi Wada, Hiroshi Nakamura, Masami Fukui, Nobutatsu Yamaoka
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Patent number: 4610970Abstract: A ceramic composition capable of sintering at a sufficiently low temperature to enable the use of a low cost base metal as the electrode material in the fabrication of capacitors. The major ingredient of the composition is expressed as Ba.sub.k-x-y M.sub.x L.sub.y O.sub.k TiO.sub.2, where M is at least either of magnesium and zinc, L is at least either of strontium and calcium, k, x and y are numerals in the ranges of 1.00 to 1.04, 0.002 to 0.049, and 0.001 to 0.048, respectively, and x+y is a value in the range of 0.02 to 0.05. To this major ingredient is added a minor proportion of a mixture of lithium oxide, silicon dioxide, and, possibly, at least one of barium oxide, calcium oxide, and strontium oxide.Type: GrantFiled: November 30, 1984Date of Patent: September 9, 1986Assignee: Taiyo Yuden Co., Ltd.Inventors: Takeshi Wada, Hiroshi Nakamura, Masami Fukui, Nobutatsu Yamaoka
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Patent number: 4610969Abstract: A ceramic composition capable of sintering at a sufficiently low temperature to enable the use of a low cost base metal as the electrode material in the fabrication of capacitors. The major ingredient of the composition is expressed as Ba.sub.k-x M.sub.x O.sub.k TiO.sub.2, where M is at least either of magnesium and zinc and where k and x are numerals in the ranges of 1.00 to 1.04 and of 0.02 to 0.05, respectively. To this major ingredient is added a minor proportion of a mixture of lithium oxide, silicon dioxide, and, possibly, at least one of barium oxide, calcium oxide, and strontium oxide. For the fabrication of coherently bonded bodies of this composition, as for use as the dielectric bodies of capacitors, the moldings of the mixture of the major ingredient and additive in finely divided form are sintered in a reductive or neutral atmosphere and then reheated at a lower temperature in an oxidative atmosphere. The sintering temperature can be so low (typically from 1050.degree. to 1200.degree. C.Type: GrantFiled: November 30, 1984Date of Patent: September 9, 1986Assignee: Taiyo Yuden Co., Ltd.Inventors: Takeshi Wada, Hiroshi Nakamura, Masami Fukui, Nobutatsu Yamaoka
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Patent number: 4584282Abstract: Dielectric ceramic compositions consisting essentially of xZrO.sub.2 -yCeO.sub.2 -zSiO.sub.2 -TiO.sub.2 in which x+y+z=1 and x, y and z are represented within ranges by mole surrounded by a polygon having at its corners the points A, B, C and D of a ternary composition diagram of the attached drawing defined as follows,______________________________________ x y z ______________________________________ A 0.98 0.01 0.01 B 0.60 0.39 0.01 C 0.60 0.18 0.22 D 0.77 0.01 0.22 ______________________________________At least one oxide selected from the group consisting of Al.sub.2 O.sub.3, La.sub.2 O.sub.3 and Cr.sub.2 O.sub.3 may be further added to the above composition in an amount of from 0.05 to 1.0 parts by weight per 100 parts by weight of the above four components.Type: GrantFiled: January 17, 1985Date of Patent: April 22, 1986Assignee: Taiyo Yuden Kabushiki KaishaInventors: Kazuo Sasazawa, Nobutatsu Yamaoka
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Patent number: 4567059Abstract: An electroconductive paste consists essentially of 100 parts by weight of zinc in finely divided form, from about 0.01 to 10.00 parts by weight of a glass frit such as, typically, that of PbO-B.sub.2 O.sub.3 -SiO.sub.2 composition, and a vehicle such as alpha-terpineol containing ethylcellulose as an organic binder, for pasting the mixture of the zinc powder and the glass frit. The paste may contain an additive or additives such as the oxides of some metallic elements. By being baked on ceramic bodies at a temperature above the melting point of zinc, the paste forms conductors or electrodes of ceramic capacitors, varistors or the like. The capacitors or varistors having their conductors or electrodes thus prepared from the zinc paste are approximately equivalent in electrical and mechanical properties to those having their conductors or electrodes fabricated from a conventional silver paste.Type: GrantFiled: July 5, 1983Date of Patent: January 28, 1986Assignee: Taiyo Yuden Co., Ltd.Inventors: Nobutatsu Yamaoka, Kazuo Sasazawa
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Patent number: 4547314Abstract: Ceramic materials suitable for use in varistors, enabling the same to function not only as such but also as capacitors. The ceramic materials comprise a major proportion of SrTiO.sub.3, the balance being: (1) at least one of Nb.sub.2 O.sub.5, Ta.sub.2 O.sub.5, WO.sub.3, La.sub.2 O.sub.3, CeO.sub.2, Nd.sub.2 O.sub.3, Y.sub.2 O.sub.3, Pr.sub.6 O.sub.11, Sm.sub.2 O.sub.3, Eu.sub.2 O.sub.3, and Dy.sub.2 O.sub.3, for making the materials semiconductive; (2) Na.sub.2 O, for making surge-proof the varistors made from the ceramic materials and for improving their nonlinearity coefficients; and (3) Al.sub.2 O.sub.3, for improving the temperature dependences of the varistor voltages, as well as nonlinearity coefficients, of the varistors. Optionally the ceramic materials may further contain one or more of Ag.sub.2 O, CuO, MnO.sub.2, and SiO.sub.2, for still higher nonlinearity coefficients. Containing Al.sub.2 O.sub.3 in proportions ranging from 0.01 to 1.50 mole parts with respect to 100 mole parts of SrTiO.sub.Type: GrantFiled: June 24, 1983Date of Patent: October 15, 1985Assignee: Taiyo Yuden Co., Ltd.Inventors: Masaru Masuyama, Susumu Hirooka, Nobutatsu Yamaoka
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Patent number: 4545929Abstract: Ceramic materials suitable for use in varistors, consisting essentially of a major proportion of SrTiO.sub.3, the balance being (1) at least one of Nb.sub.2 O.sub.5, Ta.sub.2 O.sub.5, WO.sub.3, La.sub.2 O.sub.3, CeO.sub.2, Nd.sub.2 O.sub.3, Y.sub.2 O.sub.3, Sm.sub.2 O.sub.3, Pr.sub.6 O.sub.11, Eu.sub.2 O.sub.3, and Dy.sub.2 O.sub.3, for making the materials semiconductive, and (2) Na.sub.2 O, for making surge-proof the varistors made from the ceramic materials. As desired, the compositions may further include one or more of Ag.sub.2 O, CuO, MnO.sub.2, and SiO.sub.2 for a higher nonlinearity coefficient. Containing Na.sub.2 O in proportions ranging from approximately 0.02 to 2.50 mole parts, the ceramic compositions make possible the provision of varistors suffering little from current or voltage surges in use.Type: GrantFiled: July 14, 1982Date of Patent: October 8, 1985Assignee: Taiyo Yuden Co., Ltd.Inventors: Masaru Masuyama, Susumu Hirooka, Nobutatsu Yamaoka
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Patent number: 4541974Abstract: Ceramic materials suitable for use in varistors, enabling the same to function both as such and as capacitors. The ceramic compositions comprise a major proportion of SrTiO.sub.3, the balance being (1) one or more of Nb.sub.2 O.sub.5, Ta.sub.2 O.sub.5, WO.sub.3, La.sub.2 O.sub.3, CeO.sub.2, Nd.sub.2 O.sub.3, Pr.sub.6 O.sub.11, Dy.sub.2 O.sub.3, Y.sub.2 O.sub.3, and Sm.sub.2 O.sub.3, for making the compositions semiconductive, and (2) one or more of V.sub.2 O.sub.5, Cr.sub.2 O.sub.3, CuO, Cu.sub.2 O, MoO.sub.3, and MnO.sub.2, for improving the nonlinear volt-ampere characteristic of the compositions. If desired, for improving the coherency of bodies molded from the composition, there can be added one or more of GeO.sub.2, ZnO, B.sub.2 O.sub.3, and PbO. For use as varistors the mixture of the above ingredients, all in finely divided form and made coherent with a binder, is molded into desired shape under pressure.Type: GrantFiled: August 25, 1983Date of Patent: September 17, 1985Assignee: Taiyo Yuden Co., Ltd.Inventors: Nobutatsu Yamaoka, Akira Tsukada, Kazuo Sasazawa
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Patent number: 4519942Abstract: Ceramic materials suitable for use in varistors, enabling the same to function both as such and as capacitors. The ceramic compositions comprise a major proportion of SrTiO.sub.3, the balance being (1) one or more of Nb.sub.2 O.sub.5, Ta.sub.2 O.sub.5, WO.sub.3, La.sub.2 O.sub.3, CeO.sub.2, Nd.sub.2 O.sub.3, Pr.sub.6 O.sub.11, Dy.sub.2 O.sub.3, Y.sub.2 O.sub.3, and Sm.sub.2 O.sub.3, for making the compositions semiconductive, and (2) one or more of V.sub.2 O.sub.5, Cr.sub.2 O.sub.3, CuO, Cu.sub.2 O, MoO.sub.3, and MnO.sub.2, for improving the nonlinear volt-ampere characteristic of the compositions. If desired, for improving the coherency of bodies molded from the compositions, there can be added one or more of GeO.sub.2, ZnO, B.sub.2 O.sub.3, and PbO. For use as varistors the mixture of the above ingredients, all in finely divided form and made coherent with a binder, is molded into desired shape under pressure.Type: GrantFiled: July 6, 1981Date of Patent: May 28, 1985Assignee: Taiyo Yuden Co., Ltd.Inventors: Nobutatsu Yamaoka, Akira Tsukada, Kazuo Sasazawa
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Patent number: 4490318Abstract: Semiconductive ceramic materials suitable for use in varistors, consisting essentially of a major proportion of Sr(.sub.1-x)Ca.sub.x TiO.sub.3, where x is from about 0.01 to about 0.50, the balance being at least one of Nb.sub.2 O.sub.5, Ta.sub.2 O.sub.5, WO.sub.3, La.sub.2 O.sub.3, CeO.sub.2, Nd.sub.2 O.sub.3, Y.sub.2 O.sub.3, Sm.sub.2 O.sub.3, Pr.sub.6 O.sub.11 and Dy.sub.2 O.sub.3, and Na.sub.2 O. The ceramic materials may further comprise a minor proportion of at least one of Ag.sub.2 O, CuO, MnO.sub.2 and SiO.sub.2, and/or a minor proportion of Al.sub.2 O.sub.3. For the fabrication of ceramic bodies of the above compositions there are prepared mixtures of the noted ingredients in powdered form in various possible combinations, plus an organic binder. The mixtures are molded under pressure into desired shape. The moldings are first fired in a reductive or neutral atmosphere and then refired in an oxidative atmosphere. Na.sub.2 O can be included in the initial mixtures in the form of Na.sub.Type: GrantFiled: December 16, 1983Date of Patent: December 25, 1984Assignee: Taiyo Yuden Co., Ltd.Inventors: Masaru Masuyama, Susumu Hirooka, Nobutatsu Yamaoka
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Patent number: 4460622Abstract: An electroconductive paste consists essentially of 100 parts by weight of zinc in finely divided form, from about 0.01 to 15.00 parts by weight of an organic titanium compound such as, typically, tetrakisstearoxytitanium, and a vehicle, such as alpha-terpineol containing ethylcellulose as an organic binder, for pasting the mixture of the zinc powder and the organic titanium compound. The paste may contain an additive or additives such as the oxides of some metallic elements. By being baked on ceramic bodies at a temperature above the melting point of zinc, the paste forms conductors or electrodes of ceramic capacitors, varistors or the like. The conductors or electrodes thus prepared from the zinc paste are approximately equivalent in electrical and mechanical properties to those fabricated from the familiar silver paste.Type: GrantFiled: June 6, 1983Date of Patent: July 17, 1984Assignee: Taiyo Yuden Co., Ltd.Inventors: Nobutatsu Yamaoka, Kazuo Sasazawa
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Patent number: 4438214Abstract: Semiconductive ceramic materials suitable for use in varistors, consisting essentially of a major proportion of Sr.sub.(1-x) Ca.sub.x TiO.sub.3, where x is from about 0.01 to about 0.50, the balance being at least one of Nb.sub.2 O.sub.5, Ta.sub.2 O.sub.5, WO.sub.3, La.sub.2 O.sub.3, CeO.sub.2, Nd.sub.2 O.sub.3, Y.sub.2 O.sub.3, Sm.sub.2 O.sub.3, Pr.sub.6 O.sub.11 and Dy.sub.2 O.sub.3, and Na.sub.2 O. The ceramic materials may further comprise a minor proportion of at least one of Ag.sub.2 O, CuO, MnO.sub.2 and SiO.sub.2, and/or a minor proportion of Al.sub.2 O.sub.3. For the fabrication of ceramic bodies of the above compositions there are prepared mixtures of the noted ingredients in powdered form in various possible combinations, plus an organic binder. The mixtures are molded under pressure into desired shape. The moldings are first fired in a reductive or neutral atmosphere and then refired in an oxidative atmosphere. Na.sub.2 O can be included in the initial mixtures in the form of Na.sub.Type: GrantFiled: November 12, 1982Date of Patent: March 20, 1984Assignee: Taiyo Yuden Co., Ltd.Inventors: Masaru Masuyama, Susumu Hirooka, Nobutatsu Yamaoka
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Patent number: 4406701Abstract: An electroconductive paste consists essentially of 100 parts by weight of zinc in finely divided form, from about 0.01 to 10.00 parts by weight of a glass frit such as, typically, that of PbO-B.sub.2 O.sub.3 -SiO.sub.2 composition, from about 0.01 to 14.99 parts by weight of an organotitanium compound such as tetrakisstearoxytitanium, and a vehicle such as alpha-terpineol containing ethylcellulose as an organic binder, for pasting the mixture of the zinc powder, glass frit and organotitanium compound. The paste may contain an additive or additives such as the oxides of some metallic elements. By being fired on ceramic bodies at a temperature above the melting point of zinc, the paste forms conductors or electrodes of ceramic capacitors, varistors or the like.Type: GrantFiled: February 16, 1982Date of Patent: September 27, 1983Assignee: Taiyo Yuden Co., Ltd.Inventors: Nobutatsu Yamaoka, Kazuo Sasazawa
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Patent number: 4405475Abstract: A dielectric ceramic material composed of primary and secondary ingredients forming in combination a polycrystalline ceramic proper, and of insulating substances diffused throughout the intergranular boundaries of the ceramic proper for an increase in apparent relative dielectric constant. The primary ingredients comprise, in relative proportions, 91.18-99.82 wt. % SrTiO.sub.3, 0.13-5.32 wt. % Nb.sub.2 O.sub.5, and 0.05-3.50 wt. % ZnO. The secondary ingredients comprise 0.02-0.10 wt. part SiO.sub.2 and 0.01-0.03 wt. part Al.sub.2 O.sub.3 with respect to 100 wt. parts of the primary ingredients, with the weight ratio of SiO.sub.2 to Al.sub.2 O.sub.3 being from 1.5 to 5.0. The insulating substances comprise 0.03-2.90 wt. % PbO, 0.11-4.28 wt. % Bi.sub.2 O.sub.3, and 0.001-0.18 wt. % B.sub.2 O.sub.3 with respect to the total weight of the primary and the secondary ingredients.Type: GrantFiled: November 22, 1982Date of Patent: September 20, 1983Assignee: Taiyo Yuden Co., Ltd.Inventors: Kiyoshi Murase, Nobutatsu Yamaoka, Masayuki Fujimoto
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Patent number: 4405474Abstract: A dielectric ceramic material composed of primary and secondary ingredients forming in combination a polycrystalline ceramic proper, and of insulating substances diffused throughout the intergranular boundaries of the ceramic proper for an increase in apparent relative dielectric constant. The primary ingredients comprise in relative proportions, 96.70-99.83 wt. % SrTiO.sub.3, 0.15-2.30 wt. % WO.sub.3, and 0.02-1.00 wt. % CuO. The secondary ingredients comprise 0.02-0.10 wt %. part SiO.sub.2 and 0.01-0.03 wt. part Al.sub.2 O.sub.3 with respect to 100 wt. parts of the primary ingredients, with the weight ratio of SiO.sub.2 to Al.sub.2 O.sub.3 being from 1.5 to 5.0. The insulating substances comprise 0.003-2.83 wt. % PbO, 0.10-4.30 wt. % Bi.sub.2 O.sub.3, and 0.001-0.18 wt. % B.sub.2 O.sub.3 with respect to the total weight of the primary and the secondary ingredients.Type: GrantFiled: November 22, 1982Date of Patent: September 20, 1983Assignee: Taiyo Yuden Co., Ltd.Inventors: Kiyoshi Murase, Nobutatsu Yamaoka, Masayuki Fujimoto