JPH0388770A - Barium titanate-based semiconductor porcelain composition and thermistor - Google Patents
Barium titanate-based semiconductor porcelain composition and thermistorInfo
- Publication number
- JPH0388770A JPH0388770A JP1225062A JP22506289A JPH0388770A JP H0388770 A JPH0388770 A JP H0388770A JP 1225062 A JP1225062 A JP 1225062A JP 22506289 A JP22506289 A JP 22506289A JP H0388770 A JPH0388770 A JP H0388770A
- Authority
- JP
- Japan
- Prior art keywords
- mol
- less
- barium titanate
- temperature
- molar ratio
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 229910002113 barium titanate Inorganic materials 0.000 title claims abstract description 49
- JRPBQTZRNDNNOP-UHFFFAOYSA-N barium titanate Chemical compound [Ba+2].[Ba+2].[O-][Ti]([O-])([O-])[O-] JRPBQTZRNDNNOP-UHFFFAOYSA-N 0.000 title claims abstract description 37
- 239000000203 mixture Substances 0.000 title claims abstract description 20
- 239000004065 semiconductor Substances 0.000 title claims description 25
- 229910052573 porcelain Inorganic materials 0.000 title description 29
- 239000000843 powder Substances 0.000 claims abstract description 30
- VEALVRVVWBQVSL-UHFFFAOYSA-N strontium titanate Chemical compound [Sr+2].[O-][Ti]([O-])=O VEALVRVVWBQVSL-UHFFFAOYSA-N 0.000 claims abstract description 11
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 9
- 229910052746 lanthanum Inorganic materials 0.000 claims abstract description 7
- 229910052761 rare earth metal Inorganic materials 0.000 claims abstract description 7
- 229910052727 yttrium Inorganic materials 0.000 claims abstract description 7
- 229910052787 antimony Inorganic materials 0.000 claims abstract 2
- 239000011163 secondary particle Substances 0.000 claims description 30
- 239000011164 primary particle Substances 0.000 claims description 17
- 239000011148 porous material Substances 0.000 claims description 13
- 239000000919 ceramic Substances 0.000 claims description 12
- NKZSPGSOXYXWQA-UHFFFAOYSA-N dioxido(oxo)titanium;lead(2+) Chemical compound [Pb+2].[O-][Ti]([O-])=O NKZSPGSOXYXWQA-UHFFFAOYSA-N 0.000 claims description 7
- 229910052684 Cerium Inorganic materials 0.000 claims description 4
- 229910052758 niobium Inorganic materials 0.000 claims description 2
- 239000004615 ingredient Substances 0.000 claims 1
- 239000002245 particle Substances 0.000 abstract description 27
- 238000000034 method Methods 0.000 abstract description 15
- 229910003781 PbTiO3 Inorganic materials 0.000 abstract description 12
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 abstract description 12
- 229910002370 SrTiO3 Inorganic materials 0.000 abstract description 11
- 229910002971 CaTiO3 Inorganic materials 0.000 abstract description 9
- 239000000377 silicon dioxide Substances 0.000 abstract description 5
- 229910052681 coesite Inorganic materials 0.000 abstract description 4
- 229910052906 cristobalite Inorganic materials 0.000 abstract description 4
- 235000012239 silicon dioxide Nutrition 0.000 abstract description 4
- 229910052682 stishovite Inorganic materials 0.000 abstract description 4
- 229910052905 tridymite Inorganic materials 0.000 abstract description 4
- 229910052748 manganese Inorganic materials 0.000 abstract description 2
- MUBZPKHOEPUJKR-UHFFFAOYSA-N Oxalic acid Chemical compound OC(=O)C(O)=O MUBZPKHOEPUJKR-UHFFFAOYSA-N 0.000 description 63
- 239000010936 titanium Substances 0.000 description 39
- 239000013078 crystal Substances 0.000 description 28
- 239000000243 solution Substances 0.000 description 27
- 239000011133 lead Substances 0.000 description 24
- 238000003756 stirring Methods 0.000 description 17
- 239000002994 raw material Substances 0.000 description 14
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 12
- 239000002253 acid Substances 0.000 description 11
- 239000013522 chelant Substances 0.000 description 11
- 238000006243 chemical reaction Methods 0.000 description 11
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 11
- 235000006408 oxalic acid Nutrition 0.000 description 10
- 239000011575 calcium Substances 0.000 description 9
- 239000012535 impurity Substances 0.000 description 9
- 239000007788 liquid Substances 0.000 description 9
- 239000011572 manganese Substances 0.000 description 9
- 229910052751 metal Inorganic materials 0.000 description 9
- 239000002184 metal Substances 0.000 description 9
- 230000000694 effects Effects 0.000 description 8
- 238000010304 firing Methods 0.000 description 8
- 238000004519 manufacturing process Methods 0.000 description 8
- 238000002156 mixing Methods 0.000 description 8
- 150000002500 ions Chemical class 0.000 description 7
- 150000003891 oxalate salts Chemical class 0.000 description 7
- 229910052712 strontium Inorganic materials 0.000 description 7
- 229910052745 lead Inorganic materials 0.000 description 6
- 230000000704 physical effect Effects 0.000 description 6
- -1 titanate tetrahydrate Chemical class 0.000 description 6
- XJDNKRIXUMDJCW-UHFFFAOYSA-J titanium tetrachloride Chemical compound Cl[Ti](Cl)(Cl)Cl XJDNKRIXUMDJCW-UHFFFAOYSA-J 0.000 description 6
- 229910052784 alkaline earth metal Inorganic materials 0.000 description 5
- 150000001342 alkaline earth metals Chemical class 0.000 description 5
- 229910052788 barium Inorganic materials 0.000 description 5
- WDIHJSXYQDMJHN-UHFFFAOYSA-L barium chloride Chemical compound [Cl-].[Cl-].[Ba+2] WDIHJSXYQDMJHN-UHFFFAOYSA-L 0.000 description 5
- 229910001626 barium chloride Inorganic materials 0.000 description 5
- 229910052791 calcium Inorganic materials 0.000 description 5
- 230000007423 decrease Effects 0.000 description 5
- 238000010438 heat treatment Methods 0.000 description 5
- MRELNEQAGSRDBK-UHFFFAOYSA-N lanthanum(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[La+3].[La+3] MRELNEQAGSRDBK-UHFFFAOYSA-N 0.000 description 5
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 4
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 4
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 4
- 238000001816 cooling Methods 0.000 description 4
- 238000002425 crystallisation Methods 0.000 description 4
- 230000008025 crystallization Effects 0.000 description 4
- 238000000465 moulding Methods 0.000 description 4
- 229910052760 oxygen Inorganic materials 0.000 description 4
- 239000001301 oxygen Substances 0.000 description 4
- 150000003839 salts Chemical class 0.000 description 4
- 238000005245 sintering Methods 0.000 description 4
- DSAJWYNOEDNPEQ-UHFFFAOYSA-N barium atom Chemical compound [Ba] DSAJWYNOEDNPEQ-UHFFFAOYSA-N 0.000 description 3
- 238000001354 calcination Methods 0.000 description 3
- AOWKSNWVBZGMTJ-UHFFFAOYSA-N calcium titanate Chemical compound [Ca+2].[O-][Ti]([O-])=O AOWKSNWVBZGMTJ-UHFFFAOYSA-N 0.000 description 3
- 238000000354 decomposition reaction Methods 0.000 description 3
- 238000001914 filtration Methods 0.000 description 3
- 239000005416 organic matter Substances 0.000 description 3
- 238000006864 oxidative decomposition reaction Methods 0.000 description 3
- 230000002093 peripheral effect Effects 0.000 description 3
- 239000002244 precipitate Substances 0.000 description 3
- 238000001556 precipitation Methods 0.000 description 3
- 238000010532 solid phase synthesis reaction Methods 0.000 description 3
- 229910052719 titanium Inorganic materials 0.000 description 3
- 238000005406 washing Methods 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 238000003917 TEM image Methods 0.000 description 2
- 229910010252 TiO3 Inorganic materials 0.000 description 2
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 2
- 239000000654 additive Substances 0.000 description 2
- 230000000996 additive effect Effects 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- AYJRCSIUFZENHW-UHFFFAOYSA-L barium carbonate Chemical compound [Ba+2].[O-]C([O-])=O AYJRCSIUFZENHW-UHFFFAOYSA-L 0.000 description 2
- PWHCIQQGOQTFAE-UHFFFAOYSA-L barium chloride dihydrate Chemical compound O.O.[Cl-].[Cl-].[Ba+2] PWHCIQQGOQTFAE-UHFFFAOYSA-L 0.000 description 2
- GXUARMXARIJAFV-UHFFFAOYSA-L barium oxalate Chemical compound [Ba+2].[O-]C(=O)C([O-])=O GXUARMXARIJAFV-UHFFFAOYSA-L 0.000 description 2
- 229940094800 barium oxalate Drugs 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 229910000019 calcium carbonate Inorganic materials 0.000 description 2
- 235000010216 calcium carbonate Nutrition 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 230000015556 catabolic process Effects 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- RLJMLMKIBZAXJO-UHFFFAOYSA-N lead nitrate Chemical compound [O-][N+](=O)O[Pb]O[N+]([O-])=O RLJMLMKIBZAXJO-UHFFFAOYSA-N 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 239000013081 microcrystal Substances 0.000 description 2
- 239000004033 plastic Substances 0.000 description 2
- 229920003023 plastic Polymers 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 238000001878 scanning electron micrograph Methods 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 229940047908 strontium chloride hexahydrate Drugs 0.000 description 2
- AMGRXJSJSONEEG-UHFFFAOYSA-L strontium dichloride hexahydrate Chemical compound O.O.O.O.O.O.Cl[Sr]Cl AMGRXJSJSONEEG-UHFFFAOYSA-L 0.000 description 2
- LLZRNZOLAXHGLL-UHFFFAOYSA-J titanic acid Chemical compound O[Ti](O)(O)O LLZRNZOLAXHGLL-UHFFFAOYSA-J 0.000 description 2
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 description 1
- UXVMQQNJUSDDNG-UHFFFAOYSA-L Calcium chloride Chemical compound [Cl-].[Cl-].[Ca+2] UXVMQQNJUSDDNG-UHFFFAOYSA-L 0.000 description 1
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 1
- QPLDLSVMHZLSFG-UHFFFAOYSA-N Copper oxide Chemical compound [Cu]=O QPLDLSVMHZLSFG-UHFFFAOYSA-N 0.000 description 1
- 239000005751 Copper oxide Substances 0.000 description 1
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 1
- 229910000807 Ga alloy Inorganic materials 0.000 description 1
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 1
- 239000004698 Polyethylene Substances 0.000 description 1
- 229910002367 SrTiO Inorganic materials 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical class OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 1
- 239000004809 Teflon Substances 0.000 description 1
- 229920006362 Teflon® Polymers 0.000 description 1
- 230000002159 abnormal effect Effects 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 239000001110 calcium chloride Substances 0.000 description 1
- 229910001628 calcium chloride Inorganic materials 0.000 description 1
- 235000011148 calcium chloride Nutrition 0.000 description 1
- QXDMQSPYEZFLGF-UHFFFAOYSA-L calcium oxalate Chemical compound [Ca+2].[O-]C(=O)C([O-])=O QXDMQSPYEZFLGF-UHFFFAOYSA-L 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 229910000431 copper oxide Inorganic materials 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 238000005469 granulation Methods 0.000 description 1
- 230000003179 granulation Effects 0.000 description 1
- HWSZZLVAJGOAAY-UHFFFAOYSA-L lead(II) chloride Chemical compound Cl[Pb]Cl HWSZZLVAJGOAAY-UHFFFAOYSA-L 0.000 description 1
- 239000011656 manganese carbonate Substances 0.000 description 1
- 235000006748 manganese carbonate Nutrition 0.000 description 1
- 229910000016 manganese(II) carbonate Inorganic materials 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 150000007524 organic acids Chemical class 0.000 description 1
- 150000004686 pentahydrates Chemical class 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- 230000001376 precipitating effect Effects 0.000 description 1
- 238000010298 pulverizing process Methods 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- CIOAGBVUUVVLOB-UHFFFAOYSA-N strontium atom Chemical compound [Sr] CIOAGBVUUVVLOB-UHFFFAOYSA-N 0.000 description 1
- 229910000018 strontium carbonate Inorganic materials 0.000 description 1
- LEDMRZGFZIAGGB-UHFFFAOYSA-L strontium carbonate Chemical compound [Sr+2].[O-]C([O-])=O LEDMRZGFZIAGGB-UHFFFAOYSA-L 0.000 description 1
- KQAGKTURZUKUCH-UHFFFAOYSA-L strontium oxalate Chemical compound [Sr+2].[O-]C(=O)C([O-])=O KQAGKTURZUKUCH-UHFFFAOYSA-L 0.000 description 1
- 229910052718 tin Inorganic materials 0.000 description 1
- 239000011573 trace mineral Substances 0.000 description 1
- 235000013619 trace mineral Nutrition 0.000 description 1
- 229910052726 zirconium Inorganic materials 0.000 description 1
Landscapes
- Thermistors And Varistors (AREA)
- Compositions Of Oxide Ceramics (AREA)
Abstract
Description
【発明の詳細な説明】
[産業上の利用分野]
本発明は、著しい正の温度特性を有し、しかも比抵抗が
十分に低いと同時に耐電圧、抵抗温度係数に優れたチタ
ン酸バリウム系半導体MH組成物並びにサーミスターに
関する。[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a barium titanate-based semiconductor that has significantly positive temperature characteristics, has sufficiently low specific resistance, and has excellent withstand voltage and temperature coefficient of resistance. This invention relates to MH compositions and thermistors.
[従来技術とその解決しようとする課題]従来、チタン
酸バリウム系半導体磁器はチタン酸バリウムを主成分と
し、これに半導化剤としてY、La、Ceなどの希土類
元素、Hb,Sbのうち少なくとも1種を微量含有させ
たもので、常温における比抵抗を低くし、抵抗急変点(
キュリー点)を越えると著しい正の抵抗温度特性を示す
という特徴を有している。[Prior art and problems to be solved] Conventionally, barium titanate-based semiconductor porcelain has barium titanate as its main component, and rare earth elements such as Y, La, and Ce, among Hb and Sb, are added to this as a semiconducting agent. Contains a small amount of at least one kind, which lowers the specific resistance at room temperature and reduces the resistance sudden change point (
Curie point), it exhibits a significantly positive resistance-temperature characteristic.
通常、チタン酸バリウム系半導体磁器はその主成分であ
るチタン酸バリウムの影響によりキュリー点はほぼ12
0℃付近にある。Normally, barium titanate-based semiconductor porcelain has a Curie point of approximately 12 due to the influence of its main component, barium titanate.
It is around 0℃.
かかるチタン酸バリウム系半導体磁器のキュリー点を高
温側に移行させるために、Baの一部をpbで置換する
ことが知られている。また、キュリー点を低温側に移行
させるためや電気的特性を改善するため、Baの一部を
SrまたはCaで置換したり、Ttの一部をZr、Sn
などで置換するこ己も知られている。In order to shift the Curie point of such barium titanate-based semiconductor ceramics to a high temperature side, it is known to replace a part of Ba with Pb. In addition, in order to shift the Curie point to a lower temperature side and improve electrical characteristics, a part of Ba is replaced with Sr or Ca, and a part of Tt is replaced with Zr or Sn.
It is also known to replace with etc.
さらに、チタン酸バリウム系半導体磁器にMnやシリカ
、アル逅す、酸化銅等を添加することにより、キュリー
点を越えた後の抵抗温度変化率を改善したり、半導体磁
器の特性を安定化させる等、種々の試みが行われている
。(特公昭53−29386、特公昭54−10110
、特公昭63−28324等)そして、かかるチタン酸
バリウム系半導体磁器の特性を利用することにより、定
温度発熱用素子、電流制限用素子、温度制御用素子など
として使用されている。Furthermore, by adding Mn, silica, aluminum, copper oxide, etc. to barium titanate-based semiconductor porcelain, it is possible to improve the resistance temperature change rate after exceeding the Curie point and stabilize the characteristics of semiconductor porcelain. Various attempts are being made. (Tokuko Sho 53-29386, Sho 54-10110
, Japanese Patent Publication No. 63-28324, etc.) By utilizing the characteristics of such barium titanate-based semiconductor porcelain, it is used as a constant temperature heating element, a current limiting element, a temperature controlling element, etc.
そして、上記のような用途において、チタン酸バリウム
系半導体磁器ができる限り低比抵抗であることが求めら
れる用途も多いが、従来のものにおいては比抵抗が低く
なるに従って、抵抗温度特性、および破壊電圧が極端に
劣化し、例えば比抵抗が5Ω・(j程度のものでは比抵
抗と抵抗温度特性の勾配α(Z/ °c )が約7程度
しかなく、破壊電圧も約30V/am前後と低い値に留
まり[西井基:エレクトロニク・セラξクス、885月
号(1988) pp22〜27]このような低比抵抗
値を有するチタン酸バリウム系半導体磁器は実際には実
用化されていないのが現状である。In many of the above-mentioned applications, barium titanate-based semiconductor ceramics are required to have as low a resistivity as possible, but as the resistivity of conventional ceramics decreases, resistance temperature characteristics and breakdown For example, if the voltage is extremely degraded, and the resistivity is around 5Ω・(j), the gradient α (Z/°c) of resistivity and resistance temperature characteristics is only about 7, and the breakdown voltage is around 30V/am. [Moto Nishii: Electronic Ceramics, May 88th issue (1988) pp. 22-27] Barium titanate-based semiconductor porcelain with such a low resistivity value has not actually been put into practical use. is the current situation.
[課題を解決するための手段]
本発明者らはこのような現状に鑑み、上記問題点を解決
するために鋭意検討を行った結果、チタン酸バリウム系
半導体磁器の原料として通常用いられる炭酸塩または酸
化物の代わりに、主成分として使用されるB a T
103.5rTKO3、CaT)03、PbTiO3の
内、少なくともBaTto 3とSrTiO3を特定の
方法によって製造した微細で均一な一次粒子を有し、平
均粒子径が大きいシェラ酸塩を仮焼した形骸二次粒子を
用いることにより比抵抗が8Ω・C@以下と十分に低く
、しかも耐電圧、抵抗温度特性等の他の特性が非常に優
れた正抵抗温度特性を持つ磁器が得られることを見いだ
し、本発明に到達したものである。[Means for Solving the Problems] In view of the current situation, the present inventors conducted intensive studies to solve the above problems, and as a result, carbonate, which is commonly used as a raw material for barium titanate semiconductor ceramics, was developed. or B a T used as the main component instead of the oxide
103.5rTKO3, CaT)03, PbTiO3, at least BaTto3 and SrTiO3 are produced by a specific method, and have fine and uniform primary particles, and are calcined shell secondary particles with a large average particle size. It was discovered that by using porcelain with a sufficiently low specific resistance of 8 Ω・C@ or less, and with excellent positive resistance-temperature characteristics such as withstand voltage and resistance-temperature characteristics, the present invention has been reached.
すなわち本発明は、BaTiO3,SrTiO3 、C
aTt03、PbTiO3の主成分の内、少なくともB
aTiO3が0.2μm以下の一次粒子が互に繋がった
開気孔を有する形骸二次粒子でその大きさが平均150
〜250μm、50μm以下の二次粒子が5wt%以下
であるチタン酸バリウム粉末、Srτto 3が0.1
pm以下の一次粒子が互に繋がった開気孔を有する
形骸二次粒子でその大きさが平均70〜180 u m
、、BET比表面積が20〜30m2/gであるチタン
酸ストロンチウム粉末よりなり、
その主成分の組成がBaTiO3: 45〜85モル%
、SrTiO3 :1〜20モJし%、 CaTiO3
:5〜20モル%、PbTi0. : 1〜20モル
%であり前記主成分に対して半導化剤としてY、La、
Ceなどの希土類元素、Hb,Sbのうち少なくとも1
種が0.1〜0.3モル%、
さらにMn : 0.006〜0.025モル%、Si
ng : 0.1〜1モル%の&ll威よりなることを
特徴とするチタン酸バリウム系半導体磁器組成物、およ
びBaT 103SrTi03 、CaTiO3PbT
iO3の主成分の内、少なくともBaTiQ、が0.2
μm以下の一次粒子が互に繋がった開気孔を有する形骸
二次粒子でその大きさが平均150〜250μm、50
μm以下の二次粒子が5wt%以下であるチタン酸バリ
ウム粉末、SrTiO3が0,1μm以下の一次粒子が
互に繋がった開気孔を有する形骸二次粒子でその大きさ
が平均70〜180μm5BET比表面積が20〜3M
/gであるチタン酸ストロンチウム粉末、PbT iO
aが0.2μm以下の一次粒子が互に替がった開気孔を
有する形骸二次粒子でその大きさが平均50〜150μ
m120μm以下の二次粒子が5wt%以下であること
を特徴とするチタン酸鉛粉末よりなり、その組成が上記
組成物と同様のチタン酸バリウム系半導体磁器組成物、
さらに比抵抗値が8(Ω・cm)以下、α値が9(z/
”C)以上、耐電圧が60 (V/am)以上であるこ
とを特徴とするチタン酸バリウム系サーミスターを提供
するものである。That is, the present invention provides BaTiO3, SrTiO3, C
Among the main components of aTt03 and PbTiO3, at least B
aTiO3 is a skeleton secondary particle having open pores in which primary particles of 0.2 μm or less are connected to each other, and the average size is 150
~250 μm, barium titanate powder with 5 wt% or less secondary particles of 50 μm or less, Srτto 3 is 0.1
Secondary particles with an average size of 70 to 180 μm, which have open pores in which primary particles of pm or less are connected to each other.
,, Made of strontium titanate powder with a BET specific surface area of 20 to 30 m2/g, the main component of which is BaTiO3: 45 to 85 mol%
, SrTiO3: 1-20%, CaTiO3
:5 to 20 mol%, PbTi0. : 1 to 20 mol% of the main components as semiconducting agents such as Y, La,
At least one of rare earth elements such as Ce, Hb, and Sb
Seed: 0.1 to 0.3 mol%, further Mn: 0.006 to 0.025 mol%, Si
ng: 0.1 to 1 mol% of barium titanate-based semiconductor ceramic composition, and BaT 103SrTi03 , CaTiO3PbT
Among the main components of iO3, at least BaTiQ is 0.2
A skeletal secondary particle with open pores in which primary particles of less than μm are connected to each other, with an average size of 150 to 250 μm, 50
Barium titanate powder with 5wt% or less of secondary particles of 5 wt% or less, SrTiO3 is a form secondary particle with open pores in which primary particles of 0.1 μm or less are interconnected, and the average size is 70 to 180 μm5BET specific surface area is 20~3M
/g of strontium titanate powder, PbTiO
Formative secondary particles with open pores in which primary particles with a of 0.2 μm or less alternate, and whose size is on average 50 to 150 μm
A barium titanate-based semiconductor ceramic composition consisting of lead titanate powder characterized in that secondary particles with a diameter of 120 μm or less are 5 wt% or less, and whose composition is similar to the above composition;
Furthermore, the specific resistance value is 8 (Ω・cm) or less, and the α value is 9 (z/
``C)'' The present invention provides a barium titanate thermistor characterized by having a withstand voltage of 60 (V/am) or more.
まず、本発明の基本的原料となる各種シュウ酸塩の製造
方法について述べるが、これらの方法において重要な事
項は、できるだけ純度の高いシュウ酸塩を得ること、シ
ュウ酸塩中のBa、Sr、Pb、CaとTiのモル比が
できるだけ1に近くかつ各結晶間のばらつきの無いもの
を得ることである。そのため純度については原料となる
シュウ酸、四塩化チタンやHa 、 Sr 、 Pb
、 Caの塩ができるだけ高純度であることは勿論、反
め容器からの混入をさけるため反応容器はテフロン等の
耐酸性のプラスチック容器が好ましく、最終的に得られ
たシュウ酸塩はアルカリ土類を除いた他の金属不純物濃
度は数ppm以下、トータルで1100pp以下が好ま
しい、またモル比については結晶形状や粒子径が均一で
、できるだけ大きいものを得る必要があるが、それらは
以下のような製造法をとることによりうまく製造できる
ことがわかった。First, we will describe the methods for producing various oxalates, which are the basic raw materials of the present invention.The important points in these methods are to obtain oxalates with as high a purity as possible, and to reduce the concentration of Ba, Sr, and The objective is to obtain a crystal in which the molar ratio of Pb, Ca and Ti is as close to 1 as possible and there is no variation between crystals. Therefore, the purity of raw materials such as oxalic acid, titanium tetrachloride, Ha, Sr, and Pb
In addition to ensuring that the Ca salt is as pure as possible, the reaction vessel is preferably an acid-resistant plastic container such as Teflon to avoid contamination from the reaction vessel, and the final oxalate is an alkaline earth The concentration of other metal impurities other than the It was found that it could be successfully manufactured by using a manufacturing method.
初めにシェラ酸チタン酸バリウムの製造について述べる
と、反応はシュウ酸を溶解した水溶液に対し、四塩化チ
タンと塩化バリウムを溶解した溶液を添加することによ
り行うわけであるが、設定濃度としては生成するシェラ
酸チタン酸バリウム4水塩の濃度が10〜12−t%の
範囲内に入るように設定すればよい、従って、両液の水
バランスは設定濃度の範囲内であればどのような濃度で
もよいが、四塩化チタンと塩化バリウムの溶液で塩化バ
リウムが析出しないよう溶液中の塩化バリウムの濃度は
10wt%以下にする必要がある。First, let's talk about the production of barium titanate chelate. The reaction is carried out by adding a solution containing titanium tetrachloride and barium chloride to an aqueous solution containing oxalic acid. It is only necessary to set the concentration of barium chelate titanate tetrahydrate to be within the range of 10 to 12-t%. Therefore, the water balance of both solutions can be adjusted to any concentration as long as it is within the set concentration range. However, in order to prevent barium chloride from precipitating in a solution of titanium tetrachloride and barium chloride, the concentration of barium chloride in the solution needs to be 10 wt % or less.
Ba/Ti (モル比)はBaが若干多目の1.02〜
1.05に設定する必要がある。 Ba/Ti(モル比
)が1.02より小さい場合は生成するシュウ酸塩のB
a/Ti(モル比)が0.998より小さい値となり好
ましくなく、一方Ba/Ti(モル比)が1305より
大きい場合は、生成するシュウ酸塩のBa/Ti (モ
ル比)は1.0付近で太きく変化しないが未反応のBa
が多くなるため経済的でない、シュウ酸/Tt(モル比
)のモル比は、収量および経済性の点から2.1〜2.
3の範囲に設定するのが好ましい、また、他の塩の析出
を抑えしかも経済的な濃度、および結晶の形状等からみ
て濃度が10〜12wt%の範囲が好ましい。Ba/Ti (mole ratio) is 1.02~ with slightly more Ba
It is necessary to set it to 1.05. When Ba/Ti (molar ratio) is less than 1.02, B of the oxalate produced
If the a/Ti (molar ratio) is less than 0.998, which is undesirable, on the other hand, if the Ba/Ti (molar ratio) is larger than 1305, the Ba/Ti (molar ratio) of the oxalate produced is 1.0. Unreacted Ba that does not change greatly in the vicinity
The molar ratio of oxalic acid/Tt (molar ratio), which is uneconomical due to the large amount of
It is preferable to set the concentration in the range of 3. In addition, the concentration is preferably in the range of 10 to 12 wt% in view of the economical concentration and the shape of the crystals while suppressing the precipitation of other salts.
さらに生成するシェラ酸チタン酸バリウム4水塩の結晶
の大きさ、形状、粒度分布に大きな影響を与えるのは添
加条件、攪拌状態、温度条件であり、添加はなるべく広
い範囲にシャワー状で添加するのがよく、添加時に十分
分散しないと微細な結晶が析出し、また4時間以上かけ
てゆっくり、少量づつ添加しないと同様の現象がおこり
、最終製品の物性が劣化する原因となる。攪拌状態につ
いても同様であり、容器のスケールや形状において若干
異なるが、少なくとも攪拌周速2.5a+/seeで行
う必要がある。Furthermore, the addition conditions, stirring conditions, and temperature conditions have a major influence on the crystal size, shape, and particle size distribution of the barium chelate titanate tetrahydrate that is formed, so addition should be done in a shower over as wide a range as possible. If it is not sufficiently dispersed during addition, fine crystals will precipitate, and if it is not added slowly and in small amounts over 4 hours or more, a similar phenomenon will occur, causing deterioration of the physical properties of the final product. The same applies to the stirring state, and although it differs slightly depending on the scale and shape of the container, it is necessary to perform the stirring at at least a peripheral speed of 2.5a+/see.
次に温度条件であるが、晶析温度およびその温度の変動
は晶析に大きな影響を及ぼし微結晶の析出の大きな原因
となるので、55〜75°Cの温度範囲で一定温度に保
つ必要があり、55℃より低い温度では結晶性の悪い結
晶が生成し、Ba/Ti(モル比)が0.998より小
さい値となり、一方75℃より高い場合は晶出した結晶
が不安定で結晶中からBaが抜けやすく濾過までの時間
が長くなった場合、Ba/Ti(モル比)が0.998
より低くなるため好ましくない。Next, regarding temperature conditions, the crystallization temperature and temperature fluctuations have a great effect on crystallization and are a major cause of precipitation of microcrystals, so it is necessary to maintain a constant temperature within the temperature range of 55 to 75°C. If the temperature is lower than 55℃, crystals with poor crystallinity will be formed and the Ba/Ti (molar ratio) will be smaller than 0.998, while if the temperature is higher than 75℃, the crystals will be unstable and If the time until filtration is long, Ba/Ti (molar ratio) is 0.998.
This is not desirable because it becomes lower.
このようにして析出したシュウ酸チタン酸バリウムの結
晶は、Ba/Ti(モル比)が0.998〜1.002
の範囲内で、結晶内部も化学量論的に均一であり、結晶
粒径は平均100μm以上で揃っており、小さな結晶の
少ないものとなる。The barium titanate oxalate crystals precipitated in this way have a Ba/Ti (molar ratio) of 0.998 to 1.002.
Within this range, the inside of the crystal is stoichiometrically uniform, the crystal grain size is uniform with an average of 100 μm or more, and there are few small crystals.
次にシェラ酸チタン酸ストロンチウムの製造法であるが
、シェラ酸チタン酸バリウムに比較してSr/T i
(モル比)が1より小さい値になり易いため仕込みのS
r/Ti (モル比)を1.2以上に設定する必要があ
る。設定Sr/T i (モル比)が1.2より小さい
と、生成シュウ酸塩のSr/Ti(モル比)が0.99
8より小さい値となり好ましくないが、余り大きすぎて
も経済的でなく、普通は1,2〜1.3の範囲で設定す
る。シェラ酸/Ti(モル比〉のモル比は、収量および
経済性の点から2.1〜2.3の範囲に設定するのが好
ましい、また、他の塩の析出を抑えしかも経済的な濃度
、および結晶の形状等からみて、濃度は10〜14wt
%の範囲が好ましい。Next is the method for producing strontium titanate chelate. Compared to barium chelate titanate, Sr/Ti
(molar ratio) tends to be less than 1, so the S
It is necessary to set r/Ti (molar ratio) to 1.2 or more. When the setting Sr/Ti (molar ratio) is smaller than 1.2, the Sr/Ti (molar ratio) of the generated oxalate is 0.99.
A value smaller than 8 is not preferable, but if it is too large, it is not economical, so it is usually set in the range of 1.2 to 1.3. The molar ratio of Scheleric acid/Ti (molar ratio) is preferably set in the range of 2.1 to 2.3 from the viewpoint of yield and economic efficiency. , and the shape of the crystals, the concentration is 10 to 14 wt.
A range of % is preferred.
さらに生成するシュウ酸チタン酸ストロンチウム5水塩
の結晶の大きさ、形状、粒度分布に大きな影響を与える
のは添加条件、攪拌状態、温度条件であり、添加はなる
べく広い範囲にシャワー状で添加するのがよく、添加時
に十分撹拌分散させないと微細な結晶が析出し、また2
時間以上かけてゆっくり、少量づつ添加しないと同様の
現象がおこり、結晶のSr/Ti (モル比)が0.9
98より小さくなり好ましくない、攪拌条件についても
同様であり、容器のスケールや形状において若干異なる
が、少なくとも攪拌周速3.0s/secで行う必要が
ある。Furthermore, the addition conditions, stirring conditions, and temperature conditions have a major influence on the size, shape, and particle size distribution of the crystals of strontium oxalate titanate pentahydrate that are formed, so addition should be done in a shower over as wide a range as possible. If the addition is not sufficiently stirred and dispersed, fine crystals will precipitate, and 2.
A similar phenomenon will occur if the Sr/Ti (molar ratio) of the crystals is not added slowly and in small amounts over a period of time to 0.9.
The same applies to the stirring conditions, which are less than 98, which is undesirable, and the stirring conditions must be at least 3.0 s/sec, although they differ slightly depending on the scale and shape of the container.
次に温度条件であるが、晶析温度およびその温度の変動
は晶析に大きな影響を及ぼし微結晶の析出の大きな原因
となるので、60〜80℃とシュウ酸チタン酸バリウム
に比較してより高い温度範囲で一定温度に保つ必要があ
り、シュウ酸チタン酸バリウムと同様の理由で、上記範
囲より高い場合も低い場合もSr/Ti (モル比〉が
0.998より小さい値となり好ましくない。Next, regarding temperature conditions, the crystallization temperature and its temperature fluctuations have a large effect on crystallization and are a major cause of precipitation of microcrystals, so it is 60 to 80 °C compared to barium titanate oxalate. It is necessary to maintain a constant temperature in a high temperature range, and for the same reason as barium oxalate titanate, Sr/Ti (molar ratio) becomes less than 0.998 whether it is higher or lower than the above range, which is undesirable.
このようにして析出したシェラ酸チタン酸ストロンチウ
ムの結晶も、Sr/Ti(モル比)が0.998〜1
、002の範囲内で、結晶内部も化学量論的に均一であ
り、結晶粒径は平均70μm以上で揃っており小さな結
晶の少ないものとなる。The crystals of strontium titanate chelate thus precipitated also have a Sr/Ti (molar ratio) of 0.998 to 1.
, 002, the inside of the crystal is also stoichiometrically uniform, the crystal grain size is uniform with an average of 70 μm or more, and there are few small crystals.
シュウ酸チタン酸ストロンチウムの場合は、反応温度の
60〜80“Cでは収率が約80wt%と低いため反応
後に冷却することにより収率を90−t%以上に上げる
ことができる。しかし、冷却速度によりその後析出する
シュウ酸塩のSr/Ti(モル比)が変わってくるため
その冷却速度は5°C/hr〜30℃/Hrの範囲内で
行う必要がある。In the case of strontium titanate oxalate, the yield is as low as about 80 wt% at a reaction temperature of 60-80"C, so the yield can be increased to 90-t% or more by cooling after the reaction. However, cooling Since the Sr/Ti (mole ratio) of the oxalate that is subsequently precipitated changes depending on the cooling rate, the cooling rate must be within the range of 5°C/hr to 30°C/hr.
更に、シェラ酸チタン酸鉛の製造法であるが、この場合
四塩化チタンを使用すると鉛の塩を溶解させた場合、塩
化鉛の沈殿を生成するため、シェラ酸チタン酸バリウム
の場合のような方法は使えず、四塩化チタンを一旦アン
モニアにより中和して水酸化チタンのゲルを生成させ、
十分濾過洗浄を行った後シェラ酸に溶解すれば溶液状と
なるので、この溶液を使用することができる。シュウ酸
チタン酸鉛の場合、条件によってPb/Ti(モル比)
が変動するので種々の条件を一定にする必要があるが、
完全な溶液とするためおよび後のンユウ酸塩生成時の収
率等を考え、かつモル比が1に近い条件では、シェラ酸
/Ti(モル比)は2゜1〜2.3、TiO2: 4w
t%以下とする必要がある。トータルの水バランスから
考えると、生成するシュウ酸チタン酸鉛の濃度が10〜
18社%になるように設定すればよくその範囲内になる
よう、Tiがシェラ酸に溶解した溶液と硝酸鉛の濃度を
設定すればよい。Furthermore, regarding the manufacturing method of lead titanate Scheler acid, in this case, if titanium tetrachloride is used, lead chloride precipitates will be generated when the lead salt is dissolved, so it is not necessary to use titanium tetrachloride as in the case of barium titanate Scheler acid. method could not be used, so titanium tetrachloride was once neutralized with ammonia to generate a titanium hydroxide gel.
After thorough filtration and washing, it becomes a solution by dissolving it in Scherer's acid, and this solution can be used. In the case of lead oxalate titanate, Pb/Ti (molar ratio)
varies, so it is necessary to keep various conditions constant,
In order to obtain a complete solution and considering the yield during the subsequent formation of sulfuric acid salt, and under conditions where the molar ratio is close to 1, the Scheric acid/Ti (molar ratio) is 2°1 to 2.3, TiO2: 4w
It is necessary to keep it below t%. Considering the total water balance, the concentration of lead oxalate titanate produced is 10~
The concentration of the solution of Ti dissolved in Schereric acid and the concentration of lead nitrate may be set so as to be within this range.
また、シェラ酸チタン酸鉛の濃度が10〜18社%に設
定した場合、粒径が大きくかつ均一な結晶を得ることが
できる。Further, when the concentration of lead titanate schellanate is set to 10 to 18%, it is possible to obtain uniform crystals with a large particle size.
Pb/Ti(モル比)が1に近いシュウ酸塩を得るため
には、設定Pb/T t (モル比)は1.01〜1.
03にする必要があり、設定Pb/Ti (モル比)が
1.01より低いとシュウ酸塩のPb/Ti (モル比
)が0.99以下と下がり、一方設定Pb/Ti(モル
比)が1.03より大きい場合は、反対にシュウ酸塩の
モル比が1.01と大きすぎる値となる。設定シェラ酸
/Tt(モル比)についても同様である0反応時の液温
については、45〜55°Cの範囲で行う必要があり、
この範囲外ではいずれもモル比が0.99より低くなり
好ましくない。In order to obtain oxalate with a Pb/Ti (molar ratio) close to 1, the set Pb/T t (molar ratio) should be 1.01 to 1.
If the set Pb/Ti (molar ratio) is lower than 1.01, the Pb/Ti (molar ratio) of oxalate will decrease to 0.99 or less, while the set Pb/Ti (molar ratio) When is larger than 1.03, on the other hand, the molar ratio of oxalate becomes 1.01, which is too large. The same applies to the setting Shellacic acid/Tt (molar ratio). Regarding the liquid temperature at the time of 0 reaction, it is necessary to carry out the reaction in the range of 45 to 55 ° C.
Outside this range, the molar ratio becomes lower than 0.99, which is not preferable.
シュウ酸チタン酸鉛を得る場合も、液中の拡散状態は結
晶状態に大きな影響を及ぼし、なるべく均一かつ早い拡
散が起こるよう、添加はシャワー状態で行い、攪拌周速
は2.01/see以上で行う必要がある。When obtaining lead oxalate titanate, the diffusion state in the liquid has a great influence on the crystalline state, so to ensure as uniform and fast diffusion as possible, the addition should be carried out in a shower state, and the stirring circumferential speed should be at least 2.01/see. It is necessary to do so.
このようにして析出したシェラ酸チタン酸鉛の結晶も、
Pb/Ti(モル比)が0.998〜1.002の範囲
内で、結晶内部も化学量論的に均一であり、結晶粒径は
平均50μm以上で揃っており、小さな結晶の少ないも
のとなる。The crystals of lead titanate chelate precipitated in this way also
When the Pb/Ti (molar ratio) is within the range of 0.998 to 1.002, the inside of the crystal is stoichiometrically uniform, the crystal grain size is uniform at an average of 50 μm or more, and there are few small crystals. Become.
本発明の粉末組成物の一つであるチタン酸カルシウムに
ついても、チタン酸ストロンチウム等を製造するのと同
様に、Ca/T t (モル比) 、CaCl2の濃度
、シェラ酸/Ti(モル比)、生成するシュウ酸塩の濃
度、液の温度、添加の方法、攪拌の条件等を設定するこ
とにより、Ca/T i (モル比)が1に近く結晶粒
径が同様に大きく整ったシェラ酸チタン酸カルシウムを
得ることができる。Regarding calcium titanate, which is one of the powder compositions of the present invention, Ca/T t (molar ratio), CaCl2 concentration, Scheric acid/Ti (molar ratio) By setting the concentration of the oxalate to be produced, the temperature of the liquid, the addition method, the stirring conditions, etc., it is possible to produce Scheler acid with a Ca/Ti (molar ratio) close to 1 and a similarly large crystal grain size. Calcium titanate can be obtained.
前述の方法により得られたそれぞれのシュウ酸塩は、有
機酸のプロト′ンが金属または金属酸化物で置き換えら
れた形になっており、これを十分酸素の存在する雰囲気
中、普通の焼結を行う温度よりは若干低い温度で仮焼成
することにより有機物が酸化分解し、BaT i03.
5rTt03、PbTiO3、CaTiO3のような形
の酸化物となるわけであるが、この際の分解前の有機物
の結晶状態が焼成後の酸化物の粒径、粒度分布、モル比
等の物性に大きな影響を与え、さらに上記物性が最終的
な焼結体の電気的性質にも大きく影響する。Each oxalate obtained by the above-mentioned method is in a form in which the protons of the organic acid are replaced by metals or metal oxides, and is subjected to ordinary sintering in an atmosphere containing sufficient oxygen. By pre-calcining at a temperature slightly lower than the temperature at which the organic matter is oxidized and decomposed, BaT i03.
Oxides in the form of 5rTt03, PbTiO3, and CaTiO3 are formed, but the crystalline state of the organic matter before decomposition has a large effect on the physical properties of the oxide after firing, such as particle size, particle size distribution, and molar ratio. Moreover, the above-mentioned physical properties greatly influence the electrical properties of the final sintered body.
本発明で得られたシュウ酸塩の仮焼体は、0.25m程
度以下の均一で微細な粒子が軽く焼結してお互いに結合
力を持ち、分解前のシュウ酸塩の形を保持したいわゆる
形骸粒子の構造をとっておりしかもその粒子は原子分布
の片寄りがなく均一に分布しており、このような仮焼体
を使用して後述する混合、焼成工程により焼結体を得る
ことにより焼結体自体も均一なamを持ち、低比抵抗で
抵抗温度係数が高くかつ耐電圧の高い磁器となる。The calcined body of oxalate obtained in the present invention has homogeneous fine particles of about 0.25 m or less that are lightly sintered to have a bonding force with each other and maintain the shape of the oxalate before decomposition. It has the structure of so-called skeleton particles, and the particles are uniformly distributed without uneven atomic distribution, and it is possible to obtain a sintered body using such a calcined body through the mixing and firing processes described later. As a result, the sintered body itself has a uniform am, and becomes a porcelain having a low resistivity, a high temperature coefficient of resistance, and a high withstand voltage.
まずシュウ酸チタン酸バリウム、シェラ酸チタン酸スト
ロンチウム、シュウ酸チタン酸カルシウムの仮焼成につ
いて具体的に述べると、得られたそれぞれのシュウ酸塩
は、結晶水が飛散しない程度の温度で乾燥されており含
水塩となっているが、これを有機物が炭化せずかつ粒子
がa=iな大きさに留まる程度の温度で焼成する。従っ
て焼成時の炉内は酸素が十分供給される雰囲気中で行う
必要があるが、有機酸塩は急激な分解燃焼を起こす場合
があるので余り過剰な酸素は必要でなく、適度な酸素雰
囲気で行うことが好ましい。仮焼成温度は700〜90
0°Cが好ましく、700℃より低い場合は十分に酸化
分解が進行せず、炭素等が残留するため好ましくなく。First, to specifically describe the pre-calcination of barium oxalate titanate, strontium chelate titanate, and calcium oxalate titanate, each of the obtained oxalates is dried at a temperature that does not allow crystal water to scatter. The resulting hydrated salt is calcined at a temperature that does not carbonize the organic matter and maintains the size of the particles such that a=i. Therefore, it is necessary to carry out firing in an atmosphere that is sufficiently supplied with oxygen in the furnace, but since organic acid salts may cause rapid decomposition and combustion, excessive oxygen is not necessary, and a moderate oxygen atmosphere is necessary. It is preferable to do so. Preliminary firing temperature is 700-90
0°C is preferable, and if it is lower than 700°C, oxidative decomposition will not proceed sufficiently and carbon etc. will remain, which is not preferable.
一方900 ’Cより高い場合、不均一な粒成長が起き
やすく、局所的な異常粒成長が認められる場合が多く好
ましくない。On the other hand, if the temperature is higher than 900'C, non-uniform grain growth tends to occur, and local abnormal grain growth is often observed, which is not preferable.
このようにして得たシュウ酸塩の仮焼体ば、チタン酸バ
リウム、チタン酸カルシウムについては0.2μm以下
の一次粒子が互に繋がった開気孔を有する形骸二次粒子
で、その大きさが平均粒径150〜250μmであり、
50μm以下の形骸二次粒子が5wt%以下、BET比
表面積が6〜Ion(/gの整った二次粒子径を有する
仮焼体となる。The calcined bodies of oxalates obtained in this way, barium titanate and calcium titanate, are skeletal secondary particles with open pores in which primary particles of 0.2 μm or less are connected to each other, and the size is The average particle size is 150 to 250 μm,
The calcined body has a secondary particle diameter of 5 wt % or less and a BET specific surface area of 6 to 1 ion (/g) in which the secondary particles are 50 μm or less in size.
またチタン酸ストロンチウム仮焼体については、0.1
μm以下の一次粒子が互に繋がった開気孔を有する形骸
二次粒子でその大きさが平均70〜180μmであるが
、この場合シュウ酸塩の製造方法により生成した仮焼体
のBET比表面積が大きく変化し、焼結磁器が優れた特
性を示す粉末はBET比表面積が20〜30i/gの範
囲内であり、40μm以下の二次粒子も5社%以下とな
る。In addition, for the calcined strontium titanate body, 0.1
It is a skeletal secondary particle having open pores in which primary particles of less than μm are interconnected, and its size is on average 70 to 180 μm. In this case, the BET specific surface area of the calcined body produced by the oxalate production method is Powders that vary greatly and exhibit excellent properties for sintered porcelain have a BET specific surface area within the range of 20 to 30 i/g, and the secondary particles of 40 μm or less are also 5% or less.
シュウ酸チタン酸鉛の場合、上記したシュウ酸塩に比べ
酸化分解の温度が低く、粒成長しやすいため仮焼成は6
00〜800°Cが好ましく 、600 ’Cより低い
温度では同様に十分に酸化分解が進行せず、炭素等が残
留するため好ましくなく、一方800″Cより高い場合
、不均一な粒成長が起きやすく、局所的な異常粒成長が
認められる場合が多く好ましくない。このようにして得
たシュウ酸チタン酸鉛の仮焼体も、0,2μm以下の一
次粒子が互に繋がった開気孔を有する形骸二次粒子で、
その大きさが平均50〜150μmであり、20μm以
下の形骸二次粒子が5社%以下、BET比表面積が6〜
LOrrr/gの整った二次粒子径を有する仮焼体とな
る。In the case of lead oxalate titanate, the oxidative decomposition temperature is lower than the above-mentioned oxalates, and grain growth is easy, so the pre-calcination is 6
00 to 800°C is preferable; at temperatures lower than 600'C, oxidative decomposition does not proceed sufficiently and carbon, etc. remain, which is undesirable. On the other hand, at temperatures higher than 800'C, uneven grain growth occurs. The lead oxalate titanate calcined body obtained in this way also has open pores in which primary particles of 0.2 μm or less are interconnected. With vestigial secondary particles,
The average size is 50-150 μm, the proportion of secondary particles of 20 μm or less is 5% or less, and the BET specific surface area is 6-15%.
The calcined body has a uniform secondary particle size of LOrrr/g.
以上のような方法で得られたシュウ酸塩仮焼体を原料と
して、後述する方法により混合、焼成を行うわけである
が、この場合必ずしもすべてシュウ酸塩の仮焼体を使用
する必要はなく、少なくともBaTiO3,SrTiO
3についてシュウ酸塩の仮焼体を使用すればい。The oxalate calcined body obtained by the above method is used as a raw material, and is mixed and fired by the method described later. However, in this case, it is not necessary to use all oxalate calcined bodies. , at least BaTiO3, SrTiO
Regarding 3, use a calcined body of oxalate.
この場合、他のPbTiO3、CaTl03は所謂普通
の固相法により製造した使用してもよく、普通はそれぞ
れの原料粉末、例えばPbTiO3の場合はPbOとT
iO2を混合、焼成、粉砕することにより製造したPb
TiO3と同様の方法で製造したCaTiO3をシュウ
酸塩仮焼体と混合して使用することになるが、シュウ酸
塩仮焼体と平均粒径、不純物濃度とも近似している必要
があり、平均粒径は2μm以下、アルカリ土類金属を除
いた他の金属不純物は100 pp+m以下である必要
がある。In this case, the other PbTiO3 and CaTl03 may be produced by the so-called ordinary solid phase method, and usually their respective raw material powders, for example, in the case of PbTiO3, PbO and T
Pb produced by mixing, firing, and pulverizing iO2
CaTiO3 produced in the same manner as TiO3 is used by mixing with oxalate calcined body, but the average particle size and impurity concentration must be similar to those of the oxalate calcined body. The particle size must be 2 μm or less, and the amount of metal impurities other than alkaline earth metals must be 100 pp+m or less.
次に本発明の組成について説明すると、本発明は上記主
成分としてのBaTiO3−5rTu03 、CaTj
03PbTi03がBaTiO3: 45〜85モル%
、SrTiO3 :1〜20モル%、 CaTiO3:
5〜20モル%、 PbTi03=1〜20モル%か
らなり、これに対して半導化剤としてY、La、Ceな
どの希土類元素、Hb,Sbのうち少なくとも1種が0
.1〜0.3モル%、さらにMn二0.006〜0.0
25モル%、St、02 : 0.1〜1モル%が添加
されている組成である。Next, the composition of the present invention will be explained. The present invention comprises BaTiO3-5rTu03, CaTj as the main components.
03PbTi03 is BaTiO3: 45-85 mol%
, SrTiO3: 1 to 20 mol%, CaTiO3:
5 to 20 mol%, PbTi03 = 1 to 20 mol%, and at least one of rare earth elements such as Y, La, and Ce, Hb, and Sb as a semiconducting agent.
.. 1 to 0.3 mol%, further Mn2 0.006 to 0.0
25 mol%, St, 02: 0.1 to 1 mol% is added.
本発明の主成分のBaTiO3,SrTiO3 、Ca
TiO3、PbTiO3の4戒分系の磁器は、チタン酸
バリウムのBaの一部をCa、Sr、Pbで同時に置換
したものである。 Pb、Srは単独ではキエリ・−点
をそれぞれ高温便、低温側へ移行させるものであり、こ
れらCa、Sr。The main components of the present invention are BaTiO3, SrTiO3, and Ca.
TiO3, PbTiO3 four-class porcelain is made by replacing a part of Ba in barium titanate with Ca, Sr, and Pb at the same time. When used alone, Pb and Sr shift the Chieri point to the high-temperature and low-temperature sides, respectively, and these Ca and Sr.
pbを共存状態で主成分に含有させることにより、耐電
圧値が高くなり、また突入大電流への耐久性が向上する
ことが知られているが、従来法においては比抵抗が8(
Ω・cm)以下で優れた耐電圧特性を有するものは得ら
れていない。It is known that by including PB as the main component in a coexisting state, the withstand voltage value increases and the durability against large rush currents improves.However, in the conventional method, the specific resistance is 8 (
No material with excellent withstand voltage characteristics has been obtained with a voltage resistance of Ω·cm or less.
本発明の主成分は、BaTiO3: 45〜85モル%
、5rTj03: 1〜20モル%、 CaTiO3
: 5〜20モル%、PbTiO3: 1〜20モル%
よりなるが、上記範囲に主成分を限定したのは以下の理
由によるためである。The main component of the present invention is BaTiO3: 45 to 85 mol%
, 5rTj03: 1 to 20 mol%, CaTiO3
: 5-20 mol%, PbTiO3: 1-20 mol%
However, the reason why the main components are limited to the above range is as follows.
まず、BaTiO3が45%未満の場合、半導体化が困
難になり、比抵抗も高くなる。一方、85%を越えると
、電気的特性が劣化するため好ましくない。First, if BaTiO3 is less than 45%, it becomes difficult to make it into a semiconductor and the specific resistance becomes high. On the other hand, if it exceeds 85%, it is not preferable because the electrical characteristics deteriorate.
SrT!03が1モル%未満では、焼結体の粒子が粗大
となってしまい、電気的特性改善の効果が現れず、20
モル%を越えると、部分的粒成長が起こり電気的特性が
劣化してしまう。SrT! If 03 is less than 1 mol%, the particles of the sintered body will become coarse, and the effect of improving electrical properties will not appear.
If it exceeds mol%, partial grain growth will occur and electrical characteristics will deteriorate.
CaTiO3が5モル%未満では、その耐電圧特性等が
優れず、20モル%を越えた場合、上記耐電圧特性が劣
化してしまう。If CaTiO3 is less than 5 mol%, the withstand voltage characteristics are not excellent, and if it exceeds 20 mol%, the voltage withstand characteristics are deteriorated.
PbTiO3については、1モル%未満では電気的特性
が満足できるものではなく、20モル%を越えた場合、
jA戒時にpbが飛散するため焼結しにくくまた半導体
化が困難になる。Regarding PbTiO3, if it is less than 1 mol%, the electrical properties are not satisfactory, and if it exceeds 20 mol%,
Since PB scatters during heating, it becomes difficult to sinter and make it difficult to convert into a semiconductor.
なお、このとき主成分のBa、Sr、Ca、、Pbの合
計とTiのモル比については、 0.99〜1.03の
範囲内で調整すれば、製造された磁器の物性に殆ど影響
をおよぼさないものを製造できる。At this time, if the molar ratio of the sum of the main components Ba, Sr, Ca, Pb and Ti is adjusted within the range of 0.99 to 1.03, it will hardly affect the physical properties of the manufactured porcelain. We can manufacture products that do not cause any damage.
チタン酸バリウム系半導体磁器を製造するためには、半
導体化剤を微量含有させる必要があり、半導体化剤とし
てY、La、、Ceなどの希土類元素、Nb。In order to manufacture barium titanate-based semiconductor ceramics, it is necessary to contain a small amount of a semiconducting agent, such as rare earth elements such as Y, La, Ce, and Nb.
のうち少なくとも1種を0.1〜0.3モル%添加、含
有させればよい、添加量が0.1モル%より少ない場合
は、半導体化がうまくいかず、0.3モル%より多い場
合も逆に比抵抗は高(なり好ましくない、添加の際は、
シュウ酸塩か酸化物の形で添加するのが好ましい。It is sufficient to add or contain at least one of the following in an amount of 0.1 to 0.3 mol%. If the amount added is less than 0.1 mol%, semiconductor formation will not be successful, and it is more than 0.3 mol%. On the other hand, the specific resistance is high (which is undesirable), and when adding
Preferably, it is added in the form of oxalate or oxide.
さらに、上記組成にMn、SiO2を添加することによ
り、抵抗温度特性を改善させることができる。Furthermore, by adding Mn and SiO2 to the above composition, the resistance temperature characteristics can be improved.
本発明においては、固相法に比較して微量のMn、51
0gの添加で大きな特性の向上が図られているが、これ
もシュウ酸塩仮焼体を主原料として用いたため、添加剤
が非常に均一に分散し、上記効果を奏するものと考えら
れる。In the present invention, compared to the solid phase method, a trace amount of Mn, 51
A large improvement in properties was achieved with the addition of 0 g, and it is thought that because the oxalate calcined body was used as the main raw material, the additive was dispersed very uniformly and the above effect was achieved.
この場合、Mnの添加量は、Mn : 0.006〜0
.025モル%で、これらの割合で磁器中に含ませる。In this case, the amount of Mn added is Mn: 0.006 to 0
.. 025 mol %, and these proportions are included in the porcelain.
My+を添加することにより、キュリー点を越えた正
の抵抗温度特性において、その抵抗温度変化率を著しく
増大させることができる。By adding My+, the rate of change in resistance temperature can be significantly increased in the positive resistance temperature characteristic exceeding the Curie point.
上記特性を表わすパラメーターとして、抵抗温度係数(
以下、α値と略す、〉があるが、Mnが0.006モル
%より少ない場合、α値が小さくなり、耐電圧特性が劣
化する。一方、Mnが0.025モル%より多い場合は
、α値は上がるが室温での比抵抗が高くなり、低電圧で
使用する場合、作動しなくなるので好ましくない、 M
nの添加もシュウ酸塩か酸化物の形で添加すればよい。The temperature coefficient of resistance (
Hereinafter, the α value will be abbreviated as 〉. If the Mn content is less than 0.006 mol %, the α value will become small and the withstand voltage characteristics will deteriorate. On the other hand, if Mn is more than 0.025 mol%, the α value will increase, but the specific resistance at room temperature will increase, and when used at low voltage, it will not work, which is not preferable.
N may also be added in the form of oxalate or oxide.
次にSiO□の添加であるが、その量としては、5in
2: O,L = 1モル%の範囲が好ましい。Next is the addition of SiO□, the amount of which is 5 inches.
2: A range of O, L = 1 mol% is preferred.
SiO2の添加により、半導体化剤の添加のわずかな変
動によって生じる比抵抗の変化を抑制し、常温において
低い比抵抗値にしようとするものであり、SfO□が0
,1モル%より少ない場合、粒成長しやすく、耐電圧特
性が劣化し、α値が小さくなり、一方5in2が1モル
%より多い場合、比抵抗が高くなり、好ましくない、
SiO2の添加は、なるべく粒子径の小さい酸化物を
使用すればよい。The addition of SiO2 suppresses changes in resistivity caused by slight fluctuations in the addition of the semiconducting agent, and aims to achieve a low resistivity value at room temperature.
, If it is less than 1 mol%, grain growth tends to occur, the withstand voltage characteristics deteriorate, and the α value becomes small, while if 5in2 is more than 1 mol%, the specific resistance becomes high, which is undesirable.
When adding SiO2, it is sufficient to use an oxide with a particle size as small as possible.
上述のような割合で各原料粉末を秤量し、金属不純物の
混入しにくいプラスチック等のボールミル用ポットと密
度が高くしかも不純物として少量混入した場合も電気的
特性に影響を与えないジルコニア等のボールを使用して
混合、解砕を行う。Weigh each raw material powder in the proportions described above, and use a ball mill pot made of plastic, etc., which is difficult to mix with metal impurities, and balls made of zirconia, etc., which are high in density and do not affect the electrical characteristics even if a small amount of impurities are mixed in. Use for mixing and crushing.
この場合、解砕効果を上げるために水、有II溶剤等の
液体を添加してもよい、この工程の後、液体を除去し、
造粒を行い、0.3〜1.Ot/cm”の圧力で成型を
行う、成型後は、5〜10°C/sinで昇温を行い、
1300〜1400℃で5分〜2時間焼成した後に、昇
温と同様の速度で降温し、本発明の磁器を得る。成型圧
力が所定より低すぎると比抵抗が上がり、一方高すぎる
と比抵抗は下がるがα値が下がり好ましくない、また、
昇温速度が遅すぎると比抵抗が上がる、−労連すぎる場
合は比抵抗は下がるがα値も下がり好ましくない、焼成
温度については、温度が低すぎても高すぎても比抵抗が
上がり好ましくない。In this case, a liquid such as water or a solvent may be added to increase the crushing effect. After this step, the liquid is removed,
Granulation is carried out, and 0.3 to 1. Molding is carried out at a pressure of 100 t/cm". After molding, the temperature is raised at 5 to 10°C/sin.
After firing at 1300 to 1400°C for 5 minutes to 2 hours, the temperature is lowered at the same rate as the temperature rise to obtain the porcelain of the present invention. If the molding pressure is too low than the specified value, the specific resistance will increase, while if it is too high, the specific resistance will decrease, but the α value will decrease, which is undesirable.
If the heating rate is too slow, the resistivity will increase; if the temperature is too high, the resistivity will decrease, but the α value will also drop, which is not desirable. Regarding the firing temperature, if the temperature is too low or too high, the resistivity will increase, which is not desirable. .
以上のような方法で製造した本発明の磁器は、密度が5
.2〜5.6 g/c*3、比抵抗値が8(Ω・C謙)
以下、α値カ9 (z/’C)以上、耐電圧が60 (
V/1m)以上という低比抵抗で耐電圧が高く、且つα
値も高い優れたチタン酸バリウム系半導体磁器となる。The porcelain of the present invention produced by the method described above has a density of 5
.. 2 to 5.6 g/c*3, specific resistance value is 8 (Ω・C)
Below, the α value is 9 (z/'C) or more and the withstand voltage is 60 (
It has a low specific resistance of V/1m) or more, has a high withstand voltage, and
It becomes an excellent barium titanate semiconductor porcelain with a high value.
このように、原料として主成分にシュウ酸塩から製造さ
れたものを用いたために優れた電気的特性を有するよう
になった理由としては、原料の純度がアルカリ土類元素
を除いたトータルの金属元素が1100pp以下と非常
に高いため微量元素の添加により特性がコントロールし
やすくその特性改善の効果が大きいこと、磁器中の組織
がダレインサイズが10μm以下で平均サイズがおよそ
5μmに制御された整った粒径の焼結体からなる均一微
細組織となっているため耐電圧特性が向上したことが考
えられる。In this way, the reason why it has excellent electrical properties due to the use of materials manufactured from oxalate as the main component is that the purity of the raw materials is the total metal content excluding alkaline earth elements. Since the elemental content is very high at less than 1100pp, it is easy to control the properties by adding trace elements, and the effect of improving the properties is large.The structure in the porcelain is well-organized with a dalein size of less than 10μm and an average size of approximately 5μm. It is thought that this is due to the uniform microstructure consisting of a sintered body with a grain size of 100%, which improves the withstand voltage characteristics.
さらに主成分のシュウ酸塩仮焼体が適当な強度を有する
微細で均一な一次粒子が結合した形骸粒子であるため混
合解砕時に形骸粒子が順次解砕されながら混合されるの
で非常に混合性がよく、そのため焼結時に均一に各原子
が固溶し、磁器とした場合原子の分布もより均一となり
、磁器中での局所的な特性の変化がなく、全体が均一な
特性を示すことなどが考えられるが、実際には本発明の
原料の選択および製造法、混合解砕方法、焼結方法等で
最も最適な条件になるよう種々の条件を検討した結果、
総合的な効果としてこのような格段の電気的特性を有す
る磁器を得ることができたものである。Furthermore, since the oxalate calcined body, which is the main component, is a skeleton particle in which fine and uniform primary particles with appropriate strength are combined, the skeleton particles are sequentially crushed and mixed during mixing and crushing, so it is very mixable. As a result, each atom is uniformly dissolved in solid solution during sintering, and when made into porcelain, the distribution of atoms becomes more uniform, and there are no local changes in the characteristics within the porcelain, and the overall characteristics are uniform. However, as a result of actually examining various conditions to obtain the most optimal conditions for the selection of raw materials, manufacturing method, mixing and crushing method, sintering method, etc. of the present invention,
The overall effect was that we were able to obtain porcelain with such outstanding electrical properties.
これらは、定温度発熱用素子、電流制限用素子、温度制
御用素子等の用途たして極めて有用である。These are extremely useful as constant-temperature heating elements, current limiting elements, temperature control elements, and the like.
[実施例]
以下、実施例により本発明を具体的に説明するが、本発
明は係る実施例に限定されるものではない。[Examples] Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited to these Examples.
実施例1
容量が5dのゴムライニング製タンクAに、Tt(OH
) a換算で27.6wt%のTiイオン、IC!換算
で32.8wt%のClイオンを含有するTttl液6
50 Kg、塩化バリウム2水塩389Kgおよび純水
2980にgをゆっくり混合して添加用の溶液とした。Example 1 Tt (OH
) 27.6wt% Ti ion, IC! Tttl liquid 6 containing 32.8 wt% Cl ions in terms of
50 kg of barium chloride dihydrate, 389 kg of barium chloride dihydrate, and 2980 kg of pure water were slowly mixed to prepare a solution for addition.
−大容量が7m2のゴムライニング製タンクBに、シュ
ウ酸4.29 Kgを2055Kgの純水に溶解し、温
度を60℃まで昇温し、その温度に維持した。- In a rubber-lined tank B with a large capacity of 7 m2, 4.29 kg of oxalic acid was dissolved in 2055 kg of pure water, and the temperature was raised to 60°C and maintained at that temperature.
この時のHa/TI(モル比)=1.03、シュウ酸/
Ti(モル比>=2.2 、BaCl2 =8.25
wt%であった。Ha/TI (molar ratio) at this time = 1.03, oxalic acid/
Ti (molar ratio>=2.2, BaCl2 =8.25
It was wt%.
タンクAからタンクBへの溶液の添加はチャージポンプ
によって行い、添加方法はパイプの先端に約200個の
穴を設けて、シャワー状で液面に添加することにより行
った。The solution was added from tank A to tank B using a charge pump, and about 200 holes were provided at the tip of a pipe, and the solution was added to the liquid surface in a shower-like manner.
この際の撹拌は平板状の2枚の羽根を有する攪拌羽根を
50rpmで回転させることにより行い、この時の攪拌
周速は2.9m/secであった1反応中の溶液は60
℃に維持し、添加時間は4時間であった。Stirring at this time was performed by rotating a stirring blade having two flat blades at 50 rpm, and the peripheral stirring speed at this time was 2.9 m/sec.
The addition time was 4 hours.
またこの時に生成するシェラ酸チタン酸バリウムの設定
濃度は11%11七%であった。Further, the set concentration of barium titanate chelate produced at this time was 11% and 117%.
添加終了後、反応液は遠心分!11mにより濾過し洗浄
した後、50℃で乾燥することによりシェラ酸チタン酸
バリウムの結晶592Kgを得た。この時の収率は88
.3wt%で、そのBa/TK(モル比)は0.999
であった。After the addition is complete, the reaction solution is centrifuged! After filtering and washing through 11m filter, the product was dried at 50° C. to obtain 592 kg of crystals of barium titanate chelate. The yield at this time was 88
.. 3wt%, its Ba/TK (mole ratio) is 0.999
Met.
得られた粉末は磁器製のるつぼに入れ、空気中900℃
、2hrで坑底してチタン酸バリウム仮焼粉末を得た。The obtained powder was placed in a porcelain crucible and heated to 900°C in air.
, for 2 hours to obtain calcined barium titanate powder.
得られた粉末は、アルカリ土類以外の金属不純物がいず
れも10ppm以下で、平均粒径が200μmで、50
am以下の粒子が約2wt%であった。この時得られた
粉末の走査型電子顕微鏡写真(SE)4写真)を第2図
に、さらに一部を採取して一次粒子の様子を観察した透
過型電子顕微鏡写真(TEM写真)を第3図に示す。The obtained powder contained no more than 10 ppm of metal impurities other than alkaline earth metals, had an average particle size of 200 μm, and had a grain size of 50 μm.
The particles below am were about 2 wt%. Figure 2 shows scanning electron micrographs (SE) of the powder obtained at this time (4), and Figure 3 shows transmission electron micrographs (TEM) of a portion of the powder obtained to observe the state of the primary particles. As shown in the figure.
実施例2
容量が5dのゴムライニング製タンクAに、Ti(OH
)、換算で39.9ivt%のT1イオン、1(CI換
算で31.9社%のC1イオンを含有するTil液51
6 Kg、塩化ストロンチウム6水塩516Kg、純水
1590Kgをゆっくり混合して添加用の溶液とした。Example 2 Ti(OH) was placed in a rubber-lined tank A with a capacity of 5 d.
), 39.9ivt% of T1 ions, 1 (31.9% of C1 ions in terms of CI), Til solution 51
6 kg of strontium chloride hexahydrate, 516 kg of strontium chloride hexahydrate, and 1590 kg of pure water were slowly mixed to prepare a solution for addition.
−大容量が7dのゴムライニング製タンクBにシュウ酸
429 Kgを2147Kgの純水に溶解し、温度を7
5°Cまで昇温し、その温度に維持した。- Dissolve 429 kg of oxalic acid in 2147 kg of pure water in rubber-lined tank B with a large capacity of 7 d, and lower the temperature to 7 d.
The temperature was increased to 5°C and maintained at that temperature.
この時のSr/Ti (モル比)=1.25、シュウ酸
/Ti(モル比)=2.2.5rCh =f2.Owt
%であった。At this time, Sr/Ti (molar ratio) = 1.25, oxalic acid/Ti (molar ratio) = 2.2.5rCh = f2. Owt
%Met.
タンクAからタンクBへの溶液の添加はチャージポンプ
によって行い、添加方法はバイブの先端に約200個の
穴を設けて、シャワー状で液面に添加することにより行
った。The solution was added from tank A to tank B using a charge pump, and the solution was added by making about 200 holes at the tip of a vibrator and adding the solution to the liquid surface in a shower-like manner.
この際の攪拌は平板状の2枚の羽根を有する攪拌羽根を
用い、この時の攪拌周速は4.1m/secであった0
反応中の溶液は75°Cに維持し、添加時間は2.5¥
f間であった。またこの時に生成するシュウ酸チタン酸
ストロンチウムの設定濃度は12wt%であった。For stirring at this time, a stirring blade having two flat blades was used, and the stirring circumferential speed at this time was 4.1 m/sec.
The solution during the reaction was maintained at 75°C, and the addition time was 2.5 yen.
It was between f. Further, the set concentration of strontium oxalate titanate produced at this time was 12 wt%.
添加終了後、反応液を20°C/hrの速度で室温まで
冷却した後、遠心分離機により濾過し洗浄し、さらに5
0℃で乾燥することによりシェラ酸チタン酸ストロンチ
ウム5水塩の結晶600 Kgを得た。このシュウ酸塩
のSr/T [(モル比)=0.999 、収率は93
−t%であった。After the addition was completed, the reaction solution was cooled to room temperature at a rate of 20°C/hr, filtered and washed with a centrifuge, and further
By drying at 0° C., 600 kg of crystals of strontium titanate chelate pentahydrate were obtained. Sr/T of this oxalate [(molar ratio)=0.999, yield is 93
-t%.
得られた粉末は磁器製のるつぼに入れ、空気中900°
Cl2hrで坑底してチタン酸ストロンチウム仮焼粉末
を得た。得られた粉末は、アルカリ土類以外の金属不純
物がいずれも10ppm以下で、二次粒子の平均粒子径
が150μm150μm以下の二次粒子が2.5 wt
%、BET比表面積が26゜0イ/gであった。The obtained powder was placed in a porcelain crucible and heated at 900° in air.
Strontium titanate calcined powder was obtained at the bottom of the pit using Cl2hr. The obtained powder contains all metal impurities other than alkaline earth metals at 10 ppm or less, and the average particle diameter of the secondary particles is 150 μm, and the secondary particles with a diameter of 150 μm or less are 2.5 wt.
%, BET specific surface area was 26°0/g.
実施例3
TiC1m = 10wt%の溶液を40℃以下になる
よう冷却しながら、アンモニウム水溶液でPH7になる
まで中和し、ゲル状の水酸化チタンを得た後、これを濾
過、純水により洗浄する。洗浄後のゲルは直ちにシュウ
酸により溶解し、Tiイオンの濃度を測定した後、純水
およびシュウ酸によりTiイオンの濃度2.4 wt%
、シュウ酸/Ti(モル比>=2.15に調整し、この
溶液2378Kgを添加用溶液として容量7Mのゴムラ
イニング製タンクAに移液した。一方、容量が5Mのゴ
ムライニング製タンクBに硝酸鉛402 Kgと純水1
086Kgを入れ溶液とした。この時のPb/Ti(モ
ル比)=1.02、生成するシュウ酸チタン酸鉛の設定
濃度: 16.0wt%であった。Example 3 A solution of TiC1m = 10 wt% was cooled to 40°C or below and neutralized with an ammonium aqueous solution until the pH reached 7 to obtain gel-like titanium hydroxide, which was then filtered and washed with pure water. do. The gel after washing was immediately dissolved with oxalic acid, and after measuring the concentration of Ti ions, the concentration of Ti ions was reduced to 2.4 wt% using pure water and oxalic acid.
, oxalic acid/Ti (mole ratio was adjusted to >=2.15, and 2378 kg of this solution was transferred as an addition solution to a rubber-lined tank A with a capacity of 7M.Meanwhile, it was transferred to a rubber-lined tank B with a capacity of 5M. Lead nitrate 402 kg and pure water 1
086 kg was added to form a solution. At this time, Pb/Ti (molar ratio) was 1.02, and the set concentration of lead oxalate titanate to be produced was 16.0 wt%.
タンクAからタンクBへの溶液の添加はチャージポンプ
によって行い、添加方法はパイプの先端に約200個の
穴を設けて、シャワー状で液面に添加することにより行
った。The solution was added from tank A to tank B using a charge pump, and about 200 holes were provided at the tip of a pipe, and the solution was added to the liquid surface in a shower-like manner.
この際の攪拌は平板状の2枚の羽根を有する攪拌羽根を
用い、この時の攪拌周速は2.0s/secであった。For stirring at this time, a stirring blade having two flat blades was used, and the peripheral stirring speed at this time was 2.0 s/sec.
反応中の溶液は50°Cに維持し、添加時間は2.0
時間であった。The solution during the reaction was maintained at 50 °C, and the addition time was 2.0
It was time.
添加終了後、溶液を濾過洗浄し、さらに50℃で乾燥し
てシュウ酸チタン酸鉛4水塩を得た。収率は97.0w
t%、シェラ酸チタン酸鉛のPb/Ti(モル比)は0
.998であった。After the addition was completed, the solution was filtered and washed, and further dried at 50°C to obtain lead oxalate titanate tetrahydrate. Yield is 97.0w
t%, Pb/Ti (molar ratio) of lead titanate shalerate is 0
.. It was 998.
得られた粉末は磁器製のるつぼに入れ、空気中600℃
、2hrで焼成してチタン酸鉛の仮焼粉末を得た。得ら
れた粉末は、アルカリ土類以外の金属不純物がいずれも
10ppm+以下で、二次粒子の平均粒子径が140μ
m、50μm以下の二次粒子が3wt%であった。The obtained powder was placed in a porcelain crucible and heated to 600℃ in air.
, for 2 hours to obtain a calcined powder of lead titanate. The obtained powder has metal impurities other than alkaline earth metals of 10 ppm+ or less, and the average particle size of the secondary particles is 140 μm.
m, secondary particles with a size of 50 μm or less were 3 wt%.
実施例4〜19
主成分原料として、BaTiO3,SrTiO3 、P
bTiO3は実施例1〜3により製造したシュウ酸塩仮
焼粉末を用い、CaTl03としてはCaCO3とTl
O2から固相法により製造した、アルカリ土類以外の金
属不純物がいずれも10ppm以下、平均粒径が0.5
μmの粉末を用いた。Examples 4 to 19 Main component raw materials include BaTiO3, SrTiO3, P
For bTiO3, the oxalate calcined powder produced in Examples 1 to 3 was used, and for CaTl03, CaCO3 and Tl
Manufactured from O2 by solid phase method, all metal impurities other than alkaline earth metals are 10 ppm or less, and the average particle size is 0.5
Powder of μm was used.
次に、微量成分として酸化ランタン、シェラ酸マンガン
、無水ケイ酸を用いたが、酸化ランタンと無水ケイ酸に
ついては、10μm以下の粒径の粒子を用いた。これら
の各原料を第1表に示すようなm酸比になるように配合
し、バインダーを添加して501のポリエチレン製のボ
ールミル用ボットおよびジルコニア製ボールを使用し、
アルコール溶媒を添加し、24時時間式混合を行った。Next, lanthanum oxide, manganese shellate, and silicic anhydride were used as trace components, and for lanthanum oxide and silicic anhydride, particles having a particle size of 10 μm or less were used. These raw materials were blended to the m-acid ratio shown in Table 1, a binder was added, and a 501 polyethylene ball mill bot and zirconia balls were used.
Alcohol solvent was added and 24 hour mixing was performed.
これを脱水乾燥し造粒した後、成形圧力1000kg/
−で円盤状に底形した。さらにこれを1350°C12
時間焼威し、13mmφの直径で2.5■欝の厚さの円
盤状焼結体を得た。 得られた半導体磁器につき両生表
面にIn−Ga合金の電極を付与し、これを試料とした
。 これらの試料につき、キュリー点、比抵抗値、α
値、耐電圧値を測定した。その結果を第1表に示す。After dehydrating and drying this and granulating it, the molding pressure was 1000 kg/
- The bottom was shaped like a disk. Furthermore, this is heated to 1350°C12
After firing for a period of time, a disk-shaped sintered body having a diameter of 13 mm and a thickness of 2.5 mm was obtained. An In-Ga alloy electrode was provided on the amphibian surface of the obtained semiconductor porcelain, and this was used as a sample. For these samples, the Curie point, resistivity value, α
The value and withstand voltage value were measured. The results are shown in Table 1.
比較例1〜9
実施例1〜3のそれぞれの方法において、一つの条件だ
けを変化させてそれぞれシュウ酸塩を製造し、同様の方
法で仮焼し、その仮焼粉末を使用した他は、実施例4〜
19と全く同様の&lI威、方法で磁器を製造してその
電気的特性を測定した。Comparative Examples 1 to 9 In each method of Examples 1 to 3, oxalates were produced by changing only one condition, calcined in the same manner, and the calcined powder was used. Example 4~
Porcelain was manufactured using the same method as in No. 19, and its electrical properties were measured.
その時の条件および電気的特性を第2表に示す。Table 2 shows the conditions and electrical characteristics at that time.
比較例1O〜24
原料の配合組成を第3表で示す割合に設定した他は、実
施例4〜1つと同様の操作を行った。得られた磁器の物
性値を第3表に示す。Comparative Examples 1O to 24 The same operations as in Examples 4 to 1 were performed except that the composition of the raw materials was set to the proportions shown in Table 3. Table 3 shows the physical properties of the obtained porcelain.
比較例25.26
原料として、その主成分゛にはBaCO3、CaCO3
、SrCO3、Pb30 a、Tt02 、半導体化剤
としてはLa203 、添加剤としてはMnCO3,S
iO2を第3表に示す磁器組成になるよう配合した後、
実施例4〜19と全く同じ操作を行った。Comparative Example 25.26 As a raw material, its main components include BaCO3 and CaCO3.
, SrCO3, Pb30a, Tt02, La203 as a semiconductor agent, MnCO3,S as an additive.
After blending iO2 to have the porcelain composition shown in Table 3,
Exactly the same operations as in Examples 4 to 19 were performed.
本比較例での各成分の組成、および得られた磁器の物性
値を第3表に示す。Table 3 shows the composition of each component in this comparative example and the physical property values of the obtained porcelain.
上述の特性において、耐電圧については試料に電圧を印
加した後、徐々にその電圧を上昇させてゆき、試料の破
壊が生じる手前の最高印加電圧値を示したものである。In the above-mentioned characteristics, the withstand voltage is the voltage that is gradually increased after a voltage is applied to the sample, and indicates the maximum applied voltage value before the sample breaks down.
第1図は、実施例10、実施例18、実施例19で得ら
れた磁器の抵抗温度特性を図に示したものであるが、図
かられかるようにキュリー点を様々に設定できるととも
にそれらの抵抗温度特性をいずれも低比抵抗でかつ高い
α値にたもつことができる。Figure 1 shows the resistance-temperature characteristics of the porcelains obtained in Example 10, Example 18, and Example 19. Both resistivity and temperature characteristics can be maintained at low specific resistance and high α value.
r発明の効果]
本発明の微細で粒子径の整った一次粒子よりなる独特の
形状を有する二次粒子を原料を使用して焼結することに
より得られたチタン酸バリウム系半導体磁器&lI或物
は、電流制限用素子、温度制御用素子、定温度発熱用素
子等の広範囲な用途が考えられると同時に、比抵抗値が
8(Ω・C廖)以下、α値が9(Z/”C)以上、耐電
圧が60 (V/+em)以上という低抵抗で耐電圧が
高く、且つα値も高いという優れた電気的特性を示すた
め、特に低電圧用の電流制限用素子としての種々の用途
へ、応用できるものである。rEffect of the invention] Barium titanate-based semiconductor porcelain &lI obtained by sintering secondary particles having a unique shape made of fine primary particles with uniform particle size of the present invention using raw materials can be used in a wide range of applications such as current limiting elements, temperature control elements, constant temperature heating elements, etc., and has a specific resistance value of 8 (Ω・C 廖) or less and an α value of 9 (Z/"C). ), it exhibits excellent electrical properties such as low resistance and high withstand voltage of 60 (V/+em) or higher, and a high α value, so it is suitable for various applications as a current limiting element, especially for low voltages. It can be applied to various purposes.
第1図は、本発明のチタン酸バリウム系半導体磁器組成
物の抵抗温度特性図である。
0
00
50
00
温
度
(°C)
手続補正書
平底2年4月18日
2、
発明の名称
チタン酸バリウム系半導体磁器組成物
並びにサーミスター
補正をする者
代表者
和
田
角
平
4゜FIG. 1 is a resistance-temperature characteristic diagram of the barium titanate-based semiconductor ceramic composition of the present invention. 0 00 50 00 Temperature (°C) Procedural Amendment April 18, 2015 2, Title of Invention: Barium titanate-based semiconductor ceramic composition and thermistor correction representative: Wada Kakuhei 4゜
Claims (3)
_3、PbTiO_3の主成分の内、少なくともBaT
iO_3が0.2μm以下の一次粒子が互に繋がった開
気孔を有する形骸二次粒子でその大きさが平均150〜
250μm、50μm以下の二次粒子が5wt%以下で
あるチタン酸バリウム粉末、SrTiO_3が0.1μ
m以下の一次粒子が互に繋がった開気孔を有する形骸二
次粒子でその大きさが平均70〜180μm、BET比
表面積が20〜30m^2/gであるチタン酸ストロン
チウム粉末よりなり、その主成分の組成がBaTiO_
3:45〜85モル%、SrTiO_3:1〜20モル
%、CaTiO_3:5〜20モル%、PbTiO_3
:1〜20モル%であり 前記主成分に対して半導化剤としてY,La,Ceなど
の希土類元素、Nb,Sbのうち少なくとも1種が0.
1〜0.3モル%、 さらにMn:0.006〜0.025モル%、SiO_
2:0.1〜1モル%の組成よりなることを特徴とする
チタン酸バリウム系半導体磁器組成物。(1) BaTiO_3, SrTiO_3, CaTiO
_3, among the main components of PbTiO_3, at least BaT
Primary particles with an iO_3 of 0.2 μm or less are secondary particles with open pores connected to each other, and the average size is 150~
250μm, barium titanate powder with 5wt% or less of secondary particles of 50μm or less, SrTiO_3 is 0.1μ
It is composed of strontium titanate powder, which is a skeletal secondary particle having open pores in which primary particles of less than The composition of the ingredients is BaTiO_
3: 45-85 mol%, SrTiO_3: 1-20 mol%, CaTiO_3: 5-20 mol%, PbTiO_3
: 1 to 20 mol %, and at least one of rare earth elements such as Y, La, Ce, Nb, and Sb is added as a semiconducting agent to the main component.
1 to 0.3 mol%, further Mn: 0.006 to 0.025 mol%, SiO_
2: A barium titanate-based semiconductor ceramic composition characterized by having a composition of 0.1 to 1 mol%.
_3、PbTiO_3の主成分の内、少なくともBaT
iO_3が0.2μm以下の一次粒子が互に繋がった開
気孔を有する形骸二次粒子でその大きさが平均150〜
250μm、50μm以下の二次粒子が5wt%以下で
あることを特徴とするチタン酸バリウム粉末、SrTi
O_3が0.1μm以下の一次粒子が互に繋がった開気
孔を有する形骸二次粒子でその大きさが平均70〜18
0μm、BET比表面積が20〜30m^2/gである
ことを特徴とするチタン酸ストロンチウム粉末、PbT
iO_3が0.2μm以下の一次粒子が互に繋がった開
気孔を有する形骸二次粒子でその大きさが平均50〜1
50μm、20μm以下の二次粒子が5wt%以下であ
ることを特徴とするチタン酸鉛粉末よりなり、 その主成分の組成がBaTiO_3:45〜85モル%
、SrTiO_3:1〜20モル%、CaTiO_3:
5〜20モル%、PbTiO_3:1〜20モル%であ
り 前記主成分に対して半導化剤としてY,La,Ceなど
の希土類元素、Hb,Sbのうち少なくとも1種が0.
1〜0.3モル%、 さらにMn:0.006〜0.025モル%、SiO_
2:0.1〜1モル%の組成よりなることを特徴とする
チタン酸バリウム系半導体磁器組成物。(2) BaTiO_3, SrTiO_3, CaTiO
_3, among the main components of PbTiO_3, at least BaT
Primary particles with an iO_3 of 0.2 μm or less are interconnected secondary particles with open pores, and the average size is 150~
Barium titanate powder, SrTi, characterized in that secondary particles of 250 μm and 50 μm or less are 5 wt% or less
O_3 is a skeletal secondary particle with open pores in which primary particles of 0.1 μm or less are connected to each other, and the average size is 70 to 18
Strontium titanate powder, PbT, characterized by having a BET specific surface area of 0 μm and a BET specific surface area of 20 to 30 m^2/g.
Primary particles with an iO_3 of 0.2 μm or less are secondary particles with open pores connected to each other, and the average size is 50 to 1
Made of lead titanate powder characterized by secondary particles of 50 μm and 20 μm or less being 5 wt% or less, the main component of which is BaTiO_3: 45 to 85 mol%.
, SrTiO_3: 1 to 20 mol%, CaTiO_3:
5 to 20 mol%, PbTiO_3: 1 to 20 mol%, and at least one of rare earth elements such as Y, La, Ce, Hb, and Sb is added as a semiconducting agent to the main component.
1 to 0.3 mol%, further Mn: 0.006 to 0.025 mol%, SiO_
2: A barium titanate-based semiconductor ceramic composition characterized by having a composition of 0.1 to 1 mol%.
/℃)以上、耐電圧が60(V/mm)以上であること
を特徴とするチタン酸バリウム系サーミスター。(3) Specific resistance value is 8 (Ω・cm) or less, α value is 9 (%
A barium titanate thermistor having a withstand voltage of 60 (V/mm) or more.
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP1225062A JPH0388770A (en) | 1989-08-31 | 1989-08-31 | Barium titanate-based semiconductor porcelain composition and thermistor |
EP19900116692 EP0415428B1 (en) | 1989-08-31 | 1990-08-30 | Powder composition for sintering into modified barium titanate semiconductive ceramic |
DE1990609628 DE69009628T2 (en) | 1989-08-31 | 1990-08-30 | Powder composition for sintering in a modified barium titanate semiconducting ceramic. |
US07/841,210 US5219811A (en) | 1989-08-31 | 1992-02-27 | Powder composition for sintering into modified barium titanate semiconductive ceramic |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP1225062A JPH0388770A (en) | 1989-08-31 | 1989-08-31 | Barium titanate-based semiconductor porcelain composition and thermistor |
Publications (2)
Publication Number | Publication Date |
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JPH0388770A true JPH0388770A (en) | 1991-04-15 |
JPH0559068B2 JPH0559068B2 (en) | 1993-08-30 |
Family
ID=16823440
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Application Number | Title | Priority Date | Filing Date |
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JP1225062A Granted JPH0388770A (en) | 1989-08-31 | 1989-08-31 | Barium titanate-based semiconductor porcelain composition and thermistor |
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Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH03215356A (en) * | 1990-01-16 | 1991-09-20 | Murata Mfg Co Ltd | Barium titanate-based semiconductor ceramic composition |
JPH03215353A (en) * | 1990-01-16 | 1991-09-20 | Murata Mfg Co Ltd | Barium titanate-based semiconductor ceramic composition |
JPH04104948A (en) * | 1990-08-20 | 1992-04-07 | Murata Mfg Co Ltd | Positive characteristic thermister material |
EP0974982A3 (en) * | 1998-07-24 | 2000-12-13 | Murata Manufacturing Co., Ltd. | Composite material for positive temperature coefficient thermistor and method of manufacturing |
DE10021051B4 (en) * | 1999-04-28 | 2011-01-27 | Murata Mfg. Co., Ltd., Nagaokakyo-shi | Semiconductor ceramic, use of a semiconductor ceramic for a ceramic semiconductor element and a circuit protection element |
JP2011506127A (en) * | 2007-12-05 | 2011-03-03 | エプコス アクチエンゲゼルシャフト | Injection molded PTC ceramic |
US9034210B2 (en) | 2007-12-05 | 2015-05-19 | Epcos Ag | Feedstock and method for preparing the feedstock |
WO2016084562A1 (en) * | 2014-11-26 | 2016-06-02 | 株式会社村田製作所 | Barium titanate semiconductor ceramic, barium titanate semiconductor ceramic composition, and ptc thermistor for temperature detection |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
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US20090148802A1 (en) * | 2007-12-05 | 2009-06-11 | Jan Ihle | Process for heating a fluid and an injection molded molding |
-
1989
- 1989-08-31 JP JP1225062A patent/JPH0388770A/en active Granted
Cited By (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH03215356A (en) * | 1990-01-16 | 1991-09-20 | Murata Mfg Co Ltd | Barium titanate-based semiconductor ceramic composition |
JPH03215353A (en) * | 1990-01-16 | 1991-09-20 | Murata Mfg Co Ltd | Barium titanate-based semiconductor ceramic composition |
JPH04104948A (en) * | 1990-08-20 | 1992-04-07 | Murata Mfg Co Ltd | Positive characteristic thermister material |
EP0974982A3 (en) * | 1998-07-24 | 2000-12-13 | Murata Manufacturing Co., Ltd. | Composite material for positive temperature coefficient thermistor and method of manufacturing |
US6346496B2 (en) | 1998-07-24 | 2002-02-12 | Murata Manufacturing Co., Ltd. | Composite material for positive temperature coefficient thermistor, ceramic for positive temperature coefficient thermistor and method for manufacturing ceramics for positive temperature coefficient thermistor |
CN1093102C (en) * | 1998-07-24 | 2002-10-23 | 株式会社村田制作所 | Composite material and ceramic for PTC thermistor and manufacture thereof |
DE10021051B4 (en) * | 1999-04-28 | 2011-01-27 | Murata Mfg. Co., Ltd., Nagaokakyo-shi | Semiconductor ceramic, use of a semiconductor ceramic for a ceramic semiconductor element and a circuit protection element |
JP2011506127A (en) * | 2007-12-05 | 2011-03-03 | エプコス アクチエンゲゼルシャフト | Injection molded PTC ceramic |
US9034210B2 (en) | 2007-12-05 | 2015-05-19 | Epcos Ag | Feedstock and method for preparing the feedstock |
WO2016084562A1 (en) * | 2014-11-26 | 2016-06-02 | 株式会社村田製作所 | Barium titanate semiconductor ceramic, barium titanate semiconductor ceramic composition, and ptc thermistor for temperature detection |
CN107001151A (en) * | 2014-11-26 | 2017-08-01 | 株式会社村田制作所 | Barium titanate based semiconductor ceramics, barium titanate based semiconductor ceramic composition and temperature detection positive temperature coefficient thermis |
CN107001151B (en) * | 2014-11-26 | 2020-03-03 | 株式会社村田制作所 | Barium titanate-based semiconductor ceramic, barium titanate-based semiconductor ceramic composition, and positive thermistor for temperature detection |
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JPH0559068B2 (en) | 1993-08-30 |
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