JPS6125229B2 - - Google Patents
Info
- Publication number
- JPS6125229B2 JPS6125229B2 JP54018702A JP1870279A JPS6125229B2 JP S6125229 B2 JPS6125229 B2 JP S6125229B2 JP 54018702 A JP54018702 A JP 54018702A JP 1870279 A JP1870279 A JP 1870279A JP S6125229 B2 JPS6125229 B2 JP S6125229B2
- Authority
- JP
- Japan
- Prior art keywords
- powder
- piezoelectric
- particles
- etching
- pulverization
- 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.)
- Expired
Links
- 239000000843 powder Substances 0.000 claims description 101
- 239000002245 particle Substances 0.000 claims description 47
- 238000011282 treatment Methods 0.000 claims description 39
- 229910052573 porcelain Inorganic materials 0.000 claims description 38
- 239000002131 composite material Substances 0.000 claims description 30
- 239000000203 mixture Substances 0.000 claims description 22
- 239000013081 microcrystal Substances 0.000 claims description 17
- 229920000642 polymer Polymers 0.000 claims description 17
- 238000010298 pulverizing process Methods 0.000 claims description 16
- 239000000126 substance Substances 0.000 claims description 15
- 238000000137 annealing Methods 0.000 claims description 12
- 230000015572 biosynthetic process Effects 0.000 claims description 8
- 238000002156 mixing Methods 0.000 claims description 7
- 238000003486 chemical etching Methods 0.000 claims description 6
- 238000003746 solid phase reaction Methods 0.000 claims description 6
- 239000002994 raw material Substances 0.000 claims description 5
- 238000003786 synthesis reaction Methods 0.000 claims description 5
- 238000010951 particle size reduction Methods 0.000 claims 1
- 238000005530 etching Methods 0.000 description 47
- 239000000463 material Substances 0.000 description 22
- 239000013078 crystal Substances 0.000 description 19
- 239000010408 film Substances 0.000 description 17
- 238000000034 method Methods 0.000 description 16
- 230000010287 polarization Effects 0.000 description 15
- 230000005684 electric field Effects 0.000 description 14
- 230000008569 process Effects 0.000 description 14
- 239000000243 solution Substances 0.000 description 11
- 238000002441 X-ray diffraction Methods 0.000 description 9
- 230000001788 irregular Effects 0.000 description 8
- 238000003756 stirring Methods 0.000 description 8
- 229920001971 elastomer Polymers 0.000 description 7
- 238000000227 grinding Methods 0.000 description 7
- 239000005060 rubber Substances 0.000 description 7
- 239000011163 secondary particle Substances 0.000 description 7
- 239000002033 PVDF binder Substances 0.000 description 6
- 230000006378 damage Effects 0.000 description 6
- 238000010586 diagram Methods 0.000 description 6
- 239000012535 impurity Substances 0.000 description 6
- 239000012071 phase Substances 0.000 description 6
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 6
- 239000006104 solid solution Substances 0.000 description 6
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 5
- 239000000919 ceramic Substances 0.000 description 5
- 239000011362 coarse particle Substances 0.000 description 5
- 238000012360 testing method Methods 0.000 description 5
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 4
- 229910000831 Steel Inorganic materials 0.000 description 4
- 230000007547 defect Effects 0.000 description 4
- 230000006866 deterioration Effects 0.000 description 4
- 238000009826 distribution Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 229910052451 lead zirconate titanate Inorganic materials 0.000 description 4
- HFGPZNIAWCZYJU-UHFFFAOYSA-N lead zirconate titanate Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[Ti+4].[Zr+4].[Pb+2] HFGPZNIAWCZYJU-UHFFFAOYSA-N 0.000 description 4
- 239000010959 steel Substances 0.000 description 4
- 230000008901 benefit Effects 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 230000001771 impaired effect Effects 0.000 description 3
- 239000002861 polymer material Substances 0.000 description 3
- 229920005989 resin Polymers 0.000 description 3
- 239000011347 resin Substances 0.000 description 3
- 238000001878 scanning electron micrograph Methods 0.000 description 3
- 239000011882 ultra-fine particle Substances 0.000 description 3
- 210000003934 vacuole Anatomy 0.000 description 3
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 2
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 150000007513 acids Chemical class 0.000 description 2
- XECAHXYUAAWDEL-UHFFFAOYSA-N acrylonitrile butadiene styrene Chemical compound C=CC=C.C=CC#N.C=CC1=CC=CC=C1 XECAHXYUAAWDEL-UHFFFAOYSA-N 0.000 description 2
- 229920000122 acrylonitrile butadiene styrene Polymers 0.000 description 2
- 239000004676 acrylonitrile butadiene styrene Substances 0.000 description 2
- 230000009471 action Effects 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 238000009835 boiling Methods 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000013329 compounding Methods 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 230000005294 ferromagnetic effect Effects 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 229910052745 lead Inorganic materials 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 239000000155 melt Substances 0.000 description 2
- 238000001000 micrograph Methods 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 230000000704 physical effect Effects 0.000 description 2
- 229920002620 polyvinyl fluoride Polymers 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 238000005096 rolling process Methods 0.000 description 2
- 229920002545 silicone oil Polymers 0.000 description 2
- 229910052709 silver Inorganic materials 0.000 description 2
- 239000004332 silver Substances 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 230000003068 static effect Effects 0.000 description 2
- 230000002194 synthesizing effect Effects 0.000 description 2
- 229910015902 Bi 2 O 3 Inorganic materials 0.000 description 1
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 description 1
- 229910021193 La 2 O 3 Inorganic materials 0.000 description 1
- 229910013641 LiNbO 3 Inorganic materials 0.000 description 1
- 229910003251 Na K Inorganic materials 0.000 description 1
- 229910003378 NaNbO3 Inorganic materials 0.000 description 1
- 229910010413 TiO 2 Inorganic materials 0.000 description 1
- BZHJMEDXRYGGRV-UHFFFAOYSA-N Vinyl chloride Chemical compound ClC=C BZHJMEDXRYGGRV-UHFFFAOYSA-N 0.000 description 1
- 238000005299 abrasion Methods 0.000 description 1
- 229960000583 acetic acid Drugs 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 229910052784 alkaline earth metal Inorganic materials 0.000 description 1
- 150000001342 alkaline earth metals Chemical class 0.000 description 1
- 239000012670 alkaline solution Substances 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 238000000498 ball milling Methods 0.000 description 1
- 229910052788 barium Inorganic materials 0.000 description 1
- 229910002113 barium titanate Inorganic materials 0.000 description 1
- JRPBQTZRNDNNOP-UHFFFAOYSA-N barium titanate Chemical compound [Ba+2].[Ba+2].[O-][Ti]([O-])([O-])[O-] JRPBQTZRNDNNOP-UHFFFAOYSA-N 0.000 description 1
- 229910052797 bismuth Inorganic materials 0.000 description 1
- JCXGWMGPZLAOME-UHFFFAOYSA-N bismuth atom Chemical compound [Bi] JCXGWMGPZLAOME-UHFFFAOYSA-N 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 238000003490 calendering Methods 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- YACLQRRMGMJLJV-UHFFFAOYSA-N chloroprene Chemical compound ClC(=C)C=C YACLQRRMGMJLJV-UHFFFAOYSA-N 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 230000001186 cumulative effect Effects 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- NKZSPGSOXYXWQA-UHFFFAOYSA-N dioxido(oxo)titanium;lead(2+) Chemical compound [Pb+2].[O-][Ti]([O-])=O NKZSPGSOXYXWQA-UHFFFAOYSA-N 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000010828 elution Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000005621 ferroelectricity Effects 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 229910052731 fluorine Inorganic materials 0.000 description 1
- 239000011737 fluorine Substances 0.000 description 1
- -1 foreign matter Substances 0.000 description 1
- 238000009472 formulation Methods 0.000 description 1
- 239000012634 fragment Substances 0.000 description 1
- 239000012362 glacial acetic acid Substances 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 229910052746 lanthanum Inorganic materials 0.000 description 1
- 238000011068 loading method Methods 0.000 description 1
- 230000005291 magnetic effect Effects 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 239000011812 mixed powder Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012856 packing Methods 0.000 description 1
- BITYAPCSNKJESK-UHFFFAOYSA-N potassiosodium Chemical compound [Na].[K] BITYAPCSNKJESK-UHFFFAOYSA-N 0.000 description 1
- 230000005616 pyroelectricity Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- FQENQNTWSFEDLI-UHFFFAOYSA-J sodium diphosphate Chemical compound [Na+].[Na+].[Na+].[Na+].[O-]P([O-])(=O)OP([O-])([O-])=O FQENQNTWSFEDLI-UHFFFAOYSA-J 0.000 description 1
- 229940048086 sodium pyrophosphate Drugs 0.000 description 1
- MUPJWXCPTRQOKY-UHFFFAOYSA-N sodium;niobium(5+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Na+].[Nb+5] MUPJWXCPTRQOKY-UHFFFAOYSA-N 0.000 description 1
- 238000010671 solid-state reaction Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 235000019818 tetrasodium diphosphate Nutrition 0.000 description 1
- 239000001577 tetrasodium phosphonato phosphate Substances 0.000 description 1
- 229920002803 thermoplastic polyurethane Polymers 0.000 description 1
- 229920005992 thermoplastic resin Polymers 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- 229910052721 tungsten Inorganic materials 0.000 description 1
- 239000010937 tungsten Substances 0.000 description 1
- 238000007740 vapor deposition Methods 0.000 description 1
- 238000004073 vulcanization Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 238000005303 weighing Methods 0.000 description 1
Landscapes
- Inorganic Insulating Materials (AREA)
- Compositions Of Oxide Ceramics (AREA)
Description
この発明は圧電性高分子複合材料に関するもの
である。
一般にこの種圧電材料を高分子物質と強誘電性
磁器粉末との混合により得ようとする試みは既知
であり、このうち強誘電性磁器粉末は従来
BaTiO3、PdTiO3ないしはPbZrO3−PbTiO3固溶
体などの強誘電性磁器を加熱下の固相反応によつ
てつくり、あるいはニオブ酸カリウム・ナトリウ
ム(DSN)などの単結晶を合成したのち、専ら
ボールミルとか振動ミルなどの粉砕機により粉砕
することによつて所要の粒子の大きさに調整した
ものであつた。しかしながらかような粉砕工程を
経た強誘電性磁器粉末を高分子物質と複合したと
き、該磁器組成そのものから予想される圧電特性
からは著しくかけ離れて低い性能しか得られなか
つた上に、磁器粉末の配合に伴う欠点、たとえば
もろくて破れ易く、また材料の柔軟性がなくなつ
てくるため成形し難いとか、成形体が重くさらに
はコスト高になるなどの難点があり今日までのと
ころなお事実上実用化の域に達していない。
発明者らは、上記した磁器粉末によるときに生
起した上述性能劣化の原因について根本的な究明
を行ない、その結果次の知見を得た。
第一に固相反応後あるいは単結晶合成後に施さ
れる粉砕工程で微結晶中に構造破壊が生じて無数
の分域の生成とか不整化相ができること。
次にこのような微結晶内の多分域化とは不整化
相が高分子物質との複合化工程を経たのちに分極
処理を施す際には、磁器粉末に作用する実効電界
が高分子物質の誘電率との比率で数十から数百分
の一程度に著減することが避けられないことと相
まつて、たとえ複合材料の耐電圧に近いような高
電圧で分極したとしても、上記のように低下した
電界ではもはや分極がほとんど電界方向に揃わ
ず、それ故充分な圧電性を具備させ得ないこと。
このようにして磁器粉末とか単結晶を高分子物
質に混用することの意義はないに等しいのであ
る。
そこで発明者らは、数多の実験と研鑚を重ねた
結果、次に示すようにして粒径の揃つた単一分域
微結晶よりなる強誘電性磁器粉末が得られるこ
と、そしてかかる単一分域微結晶よりなる強誘電
磁器粉末は、これに対して特定の量の高分子物質
と複合することにより圧電性高分子複合材料とし
て従来比類がない卓越した性能が製造工程におけ
る何らの難点を伴うことなくして実現され得るこ
とを見い出した。
さて粒径の揃つた単一分域微結晶よりなる強誘
電性磁器粉末は次の処理を経てはじめて得られ
る。
(1) 所望の強誘電性磁器組成に対応して原料粉末
を調合し混合する。
(2) 上記調合原料粉末を加熱化固相反応または焼
結処理により合成する。
(3) 合成物を所望の粒度となるまで粉砕する。
(4) 次に粉砕物に加熱アニール処理を旋す。この
際、大気中もしくはそれ以上の酸素濃度雰囲気
中で行なうのが望ましい。
(5) さらに処理物に化学的エツチング処理を施
す。
上記処理工程中(3)において前述した如く微結晶
中に構造破壊が生じて無数の分域の生成とか不整
化相ができるけれどもこのような微結晶内の多分
域化や不整化相は、(4)の加熱アニール処理を施す
ことにより改善され又、同時に熱によつて結晶粒
子に丸味を持たせる効果も生じる上、さらに(5)の
エツチング処理を施すことにより粒径の揃つた丸
味を持つた単一分域微結晶となることがわかつ
た。
この理由は、エツチングが結晶粒界に優先的に
作用し結晶粒界に多く存在する不純物、異物、結
晶格子欠陥および非晶部分などを取り際くととも
に、融着した二次粒子を単一粒子に解離、分解す
るためである。
つまり原料とか粉砕等の工程中の不可避的に侵
入した不純物は比較的結晶粒界に析出し易いた
め、それらを有利に除去でき、またエツチング作
用により結晶表面に丸味を帯びさせ、さらに極微
結晶粒子を溶解、消滅させる長所もある。
なおエツチングに際しては軽い機械的解砕たと
えば液中撹拌などを併用するとその効果が一層高
まる。さらに温度を上げて、例えばしや沸状態で
行なえば時間を大巾に短縮できる。いずれにして
も、目的の不純物、不整層、非晶層、極微細粒子
を溶解除去するにとどめ、それ以上の結晶層の溶
出を僅少にとどめ、圧電性の劣下を生じないよう
適切な条件で行なうことが必要である。
もちろん物性論的見地から厳密にみれば、上記
のようにして得られる粉末が、すべて完全に単一
分域微結晶になつているわけではなく、不純物と
か、構造不整(格子欠陥、層状欠陥など)、また
は化学量論比からのズレや組成の不均一とか、さ
らには外的要因(熱とか応力)などによりそれな
りの分域生成がみられ、それをさけられないのは
現在の科学技術水準においては自明の事実ではあ
るものの、上記したような加熱アニール後のエツ
チング処理時に撹拌とか軽度の粉砕で見られる程
度の結晶内に生じた分域は、分極時の電圧印加に
よる電界方向への整列や電界への配向性を妨げる
要因とはならず単方向性を示す特徴を呈すること
が発明者らにより見いだされたので、便宜上ここ
では、このようにして得られる粉化物を単一分域
微結晶ということとしたもので、これに対して従
来の通常の手段による加熱合成後、通常行なわれ
る粉砕により粉化した単結晶とか磁器が、結晶の
構造破壊を生じ、無数の多分域化とさらには不整
化をおこし、電界分向への整列がもはやほとんど
みられなくなつているので、これらの多分域微結
晶から区別したものであつて、単一分域微結晶と
いつてもそれが理想的な現実に工業的に製造でき
ない物を意味するものではない。
上記の処理工程を経た実質的に単一分域結晶よ
りなる強誘電性磁器粉末は種々な高分子物質と混
合し、任意な形状たとえばフイルム又はシート状
に成形し架橋結合ないしはゴム系の場合は、加硫
処理を経て分極を行なう。
ここに実効電界が高分子物質の誘電率との比率
で数十から数百分の一程度に甚しく低くなつたと
しても粒度が均一な単一分域微結晶よりなつてい
るので電界方向に容易に揃つてとくに高い強誘
電、圧電特性を呈することが確認された。
またこのようにして得られた粉末は、加熱アニ
ール及び化学エツチングにより各粒子の形状が丸
味を持つので、高分子とのなじみがよく、空胞が
なくなり、ち密で、又極微細粒子を溶解して含ま
ぬため、可塑性、流動性に富むので加工しやす
く、且つ高密度で高性能の複合材料が、しかも極
く薄い15μmのものまで得られるようになつたこ
と、及び従来の破砕、粉砕粉末のような鋭い刃先
のような破面とか、とがつた角を持たぬため機械
的強度も大巾に向上しくりかえし衝撃力とか引張
応力に対しても、機械的損傷がない機械電気変換
体としても実用に耐える圧電性複合材料として実
地の活性を可能としたものである。
かくして単一分域微結晶よりなる強誘電性磁器
粉末を高分子物質と複合化することにより次の様
な産業分野に利用できる。
強誘電性磁器粉末が分極方向への配向性にすぐ
れかつ単方向性を持つことと、複合したものの加
工性の良いことにより、人体となじみの良い柔軟
性を必要とする生体用トランスジユーサー等には
高分子物質を高配合したものが適合し、また圧電
シート上に多数のスイツチを集積したキーボード
スイツチ等、柔軟性はやや欠けてもより高い圧電
性能を必要とするものは強誘電性磁器粉末を高配
合したものが適合する。
かように磁器粉末と高分子物質の配合割合と
か、また高分子物質の選択により広く用途に応じ
た機械的、電気的、物理的特性を有する複合物圧
電材料の提供が可能となり、機械電気変換とか電
気音響変換とか焦電用材料として今後広範囲の分
野への応用が期待できるわけである。
なお従来の破砕による多分域化を免れ得ない磁
器粉末を用いた既知シートでは、前述の如く分極
性が甚しく阻害されたので、必要性能を満たそう
として磁器粉末の高配合をとらざるを得ないため
に高分子物質との混合シートが製品化に至る各段
階で、硬くかつもろくて破れ易く、実際の用には
供され得なかつたわけであるが、この発明では必
ずしもかかる高配合とする必要がないので高分子
物質それ自体の柔軟性が有利に維持されそれにも
拘らず充分に高度な圧電性能が達成されるので、
ここにはじめて両特徴を合わせ持つ圧電性高分子
複合材料の実用化の用途が確立されたのである。
この発明は次に示すような各種結晶構造の強誘
電性磁器の単成分系、多成分系ならびにこれらを
基本組成として、その部分置換および添加変成を
したものにおいて、好適に実施することができ
る。
1 ペロブスカイト構造
(1) チタン酸バリウムとこれを中心にした固溶
体、たとえばBaTiO3、(Ba、Pb、Ca)TiO3
……など
(2) チタン酸鉛とこれを中心にした固溶体、た
とえば(Pb、La)TiO3、PbTiO3−BiFeO3
……など
(3) チタン酸ジルコン酸鉛とこれを中心にした
固溶体、たとえばPbZrO3−PbTiO3、
PbZrO3−PbSmO3−PbTiO3……など
(4) チタン酸ジルコン酸鉛と下記a、bおよび
cのごとき第3成分との固溶体より成る三成
分系磁器、
a 一般式A2+(B1/32+−B2/35+)O3であ
らわされるたとえばPb(Ni1/3−Nb2/3)
O3、Pb(Zn1/3−Nb2/3)O3、Pb(Co1/3
−Nb2/3)O3、Pb(Mg1/3−Nb2/3)O3…
…など
b 一般式A2+(B1/22+−B1/26+)O3であ
らわされるたとえばPb(Ni1/2−W1/2)
O3、Pb(Co1/2−W1/2)O3……など
c 一般式A2+(B1/23+−B1/25+)O3であ
らわされるたとえばPb(Fe1/2−Nb1/2)
O3、Pb(Sb1/2−Nb1/2)O3、Pb(Y1/2
−Nb1/2)O3……など
(5) NaNbO3を中心とする固溶体たとえば
NaNbO3、(Na−K)NbO3、Na(Ta−Nb)
O3……など
2 タングステンブロンズ構造
たとえばPbNb2O6、PbNb2O6−PbTa2O6、
PbNb2O6−BaNb2O6……など
3 ビスマス層状構造
たとえばBi4Ti3O12、Bi4PbTi4O15、
Bi4Sr2Ti5O18……など
4 その他
LiNbO3、LiTaO3……など
5 上記各成分系を基本組成とし、そのPbの一
部をアルカリ土類金属で置換したもの
6 上記各成分系(PbTiO3を含む)を基本組成
とし、副成分として次の、および各群の
うちから選ばれる一種又は二種以上を添加し、
変成したもの
() Nb2O5、Ta2O5、La2O3、Sb2O5、
Sb2O3、Bi2O3、WO3など
() MgO、Fe2O3、Sc2O3、K2Oなど
() Cr2O3、U2O3、MnO2など
これら各種強誘電性磁器の基本組成及び置換と
か副成分の添加によりそれぞれの組成のもつ固有
の優れた強誘電性、圧電性、焦電性を選択して利
用することができる。
又、同時に、粒子径の制御とか、抗電界を低く
して電場配向性をさらに高めたり逆に抗電界を上
げて、静荷重に強い複合圧電材料にしたり、経時
変化を安定化したりすることが、可能となり、用
途に適用した幅向い特性を持つ複合圧電材料を得
ることができる。
次にこの発明で、上記したような強誘電性磁器
のとくに事実上単一分域微結晶よりなる磁器粉末
と複合することができる高分子物質は、各種ゴム
すなわち天然、人造、合成および再生ゴムまたは
それらのブレンドゴム、とくにふつ素ゴムやクロ
ロプレンなど、ならびに熱可塑性樹脂、たとえば
ポリふつ化ビニリデン(PVDF)、アクリロニト
リル−ブタジエン−スチレン共重合体(ABS)、
塩化ビニル(PVC)、ポリふつ化ビニル(PVF)
などである。
なおエツチング処理液としては、一般的な酸、
アルカリ溶液でよいが、目的の不整層、非晶層を
除去するにとどめ、その内の結晶層のPb成分を
溶出して、圧電性をそこなわない時点にとどめる
配慮が必要である。
そのため、濃度は、うすい方が処理しやすいが
静止の状態では、長時間を要することになる。
しかし、温度を上げて、例えばしや沸しながら
エツチングするとか、常温でも撹拌とか軽度の粉
砕を加えて行なえば、時間も大巾に短縮できる
し、又分粒子同志の摩擦、摩耗によつて角が、さ
らに取れてより丸味を持つ単一結晶粒子が得られ
る利点がある。
次に具体的に、標準の化学エツチング処理条件
の数例を次の表1に示す。
This invention relates to piezoelectric polymer composite materials. Generally, attempts to obtain this type of piezoelectric material by mixing a polymer substance and ferroelectric porcelain powder are known;
After producing ferroelectric ceramics such as BaTiO 3 , PdTiO 3 or PbZrO 3 -PbTiO 3 solid solution through solid-state reaction under heating, or synthesizing single crystals such as potassium sodium niobate (DSN), it is exclusively produced by ball milling. The particles were adjusted to the required particle size by being pulverized using a pulverizer such as a vibrating mill. However, when ferroelectric porcelain powder that has undergone such a crushing process is combined with a polymeric substance, the piezoelectric properties are significantly different from those expected from the porcelain composition itself, and only low performance is obtained. Due to the drawbacks associated with the formulation, such as the material being brittle and easily torn, the material becoming less flexible, making it difficult to mold, and the molded product being heavy and costly, it has remained virtually unpractical to date. It has not reached the level of The inventors conducted a fundamental investigation into the cause of the above-mentioned performance deterioration that occurred when using the above-mentioned porcelain powder, and as a result, they obtained the following knowledge. First, structural destruction occurs in microcrystals during the crushing process performed after solid phase reaction or single crystal synthesis, resulting in the formation of countless domains or irregular phases. Next, multi-regionalization within microcrystals means that when the irregular phase undergoes a polarization treatment after undergoing a compounding process with a polymeric substance, the effective electric field acting on the porcelain powder is affected by the polymeric substance. Coupled with the fact that it is unavoidable that the ratio to the dielectric constant decreases significantly from tens to hundreds of times, even if polarization is performed at a high voltage close to the withstand voltage of the composite material, the above-mentioned When the electric field is lowered to 1, the polarization is almost no longer aligned in the direction of the electric field, and therefore sufficient piezoelectricity cannot be achieved. There is almost no point in mixing porcelain powder or single crystal with polymeric substances in this way. As a result of numerous experiments and research, the inventors discovered that a ferroelectric porcelain powder consisting of single-domain microcrystals with uniform grain size could be obtained as shown below, and that In contrast, ferromagnetic powder, which is made up of one-domain microcrystals, can be combined with a specific amount of polymeric material to produce piezoelectric polymer composites with unparalleled and outstanding performance without any difficulties in the manufacturing process. We have discovered that this can be achieved without the need for Now, ferroelectric porcelain powder consisting of single-domain microcrystals with uniform particle size can only be obtained through the following treatment. (1) Prepare and mix raw material powders corresponding to the desired ferroelectric ceramic composition. (2) Synthesizing the above blended raw material powder by heating solid phase reaction or sintering treatment. (3) Grind the composite to the desired particle size. (4) Next, the pulverized material is heated and annealed. At this time, it is desirable to carry out the process in the atmosphere or in an atmosphere with an oxygen concentration higher than that. (5) Furthermore, the processed material is subjected to chemical etching treatment. During the above treatment step (3), as mentioned above, structural destruction occurs in the microcrystal, resulting in the generation of countless domains and irregular phases. This is improved by applying heat annealing treatment in 4), and at the same time, the effect of rounding the crystal grains is produced by heat, and furthermore, by applying the etching treatment in (5), the grain size becomes uniform and roundness is achieved. It was found that single-domain microcrystals were obtained. The reason for this is that etching preferentially acts on grain boundaries and removes impurities, foreign matter, crystal lattice defects, amorphous parts, etc. that are present in large quantities at grain boundaries, and also removes fused secondary particles into single particles. This is because it dissociates and decomposes into In other words, impurities that inevitably enter raw materials or during processes such as pulverization are relatively easy to precipitate at grain boundaries, so they can be removed advantageously, and the etching action can round the crystal surface and further improve the ultrafine crystal grains. It also has the advantage of dissolving and disappearing. Note that the effect of etching will be further enhanced if light mechanical crushing, such as submerged stirring, is used in combination. If the temperature is raised further, for example in a low boiling state, the time can be significantly shortened. In any case, the target impurities, irregular layers, amorphous layers, and ultrafine particles should only be dissolved and removed, and the elution of further crystal layers should be kept to a minimum, and appropriate conditions should be maintained to avoid deterioration of piezoelectricity. It is necessary to do so. Of course, strictly speaking from the viewpoint of physical properties theory, the powder obtained in the above manner does not completely become single-domain microcrystals, but may contain impurities, structural irregularities (lattice defects, layer defects, etc.). ), or due to deviations from the stoichiometric ratio, non-uniform composition, or even external factors (heat, stress), etc., some domain formation is observed, and it is impossible to avoid this due to the current level of science and technology. Although it is a self-evident fact in the above-mentioned etching process after heat annealing, the domains generated within the crystal that can be seen by stirring or slight pulverization are caused by alignment in the direction of the electric field due to voltage application during polarization. The inventors have discovered that the powdered product obtained in this way exhibits unidirectional characteristics without being a factor that hinders orientation to electric fields. On the other hand, single crystals and porcelain that are powdered by conventional pulverization after heating synthesis by conventional conventional means cause structural destruction of the crystal, resulting in countless multi-regionalization and further formation. Since these have become irregular and almost no longer aligned in the electric field direction, they are distinguished from these multi-domain microcrystals, and even if they are called single-domain microcrystals, they are not ideal. This does not mean something that cannot be manufactured industrially in real life. The ferroelectric porcelain powder consisting essentially of single-domain crystals that has gone through the above processing steps is mixed with various polymeric substances, formed into any shape such as a film or sheet, and cross-linked or rubber-based. , polarization is performed through vulcanization treatment. Here, even if the effective electric field becomes extremely low, from several tens to several hundred times lower than the dielectric constant of the polymer material, the grain size is made up of single-domain microcrystals with uniform grain size, so the electric field It was confirmed that they were easily assembled and exhibited particularly high ferroelectric and piezoelectric properties. In addition, the powder obtained in this way has a rounded shape of each particle due to heat annealing and chemical etching, so it is compatible with polymers, has no vacuoles, is dense, and has the ability to dissolve ultrafine particles. It has become possible to obtain high-density, high-performance composite materials that are easy to process due to their high plasticity and fluidity, and are even as thin as 15 μm. Since it does not have a fracture surface like a sharp cutting edge or a sharp corner, its mechanical strength is greatly improved, and it can be used as a mechanical and electrical transducer without mechanical damage even when subjected to impact force or tensile stress. This material has also been made into a piezoelectric composite material that can be used in practical applications. Thus, by combining ferroelectric porcelain powder consisting of single-domain microcrystals with a polymeric substance, it can be used in the following industrial fields. The ferroelectric ceramic powder has excellent orientation in the polarization direction and is unidirectional, and the composite material has good processability, making it ideal for biological transducers that require flexibility that is compatible with the human body. Ferroelectric porcelain is suitable for devices that require higher piezoelectric performance even if it lacks flexibility, such as keyboard switches that have a large number of switches integrated on a piezoelectric sheet. A product containing a high proportion of powder is suitable. In this way, it is possible to provide composite piezoelectric materials with mechanical, electrical, and physical properties that suit a wide range of applications, depending on the blending ratio of porcelain powder and polymeric substances, and the selection of polymeric substances. It can be expected to be applied to a wide range of fields in the future, such as electroacoustic conversion and pyroelectric materials. In addition, in known sheets using porcelain powder that cannot avoid multi-regionalization due to conventional crushing, the polarization is severely inhibited as described above, so a high proportion of porcelain powder has to be used in order to meet the required performance. Because of this, the mixed sheet with the polymeric material was hard, brittle, and easily torn at each stage of productization, and could not be put to practical use.However, in this invention, such a high blending ratio is not necessarily required. Since the flexibility of the polymeric material itself is advantageously maintained and a sufficiently high degree of piezoelectric performance is achieved despite this,
This was the first time that a practical application for a piezoelectric polymer composite material that had both characteristics was established. The present invention can be suitably carried out in the following single-component systems, multi-component systems of ferroelectric ceramics having various crystal structures as shown below, as well as those obtained by partial substitution and addition modification of these basic compositions. 1 Perovskite structure (1) Barium titanate and solid solutions around it, such as BaTiO 3 , (Ba, Pb, Ca)TiO 3
... etc. (2) Lead titanate and solid solutions centered on it, such as (Pb, La)TiO 3 , PbTiO 3 −BiFeO 3
...etc. (3) Lead zirconate titanate and solid solutions based on it, such as PbZrO 3 −PbTiO 3 ,
PbZrO 3 −PbSmO 3 −PbTiO 3 ... etc. (4) Three-component porcelain consisting of a solid solution of lead zirconate titanate and a third component such as a, b and c below, a General formula A 2+ (B1/ For example, Pb(Ni1/3−Nb2/3) expressed as 3 2+ −B2/3 5+ )O 3
O 3 , Pb (Zn1/3−Nb2/3) O 3 , Pb (Co1/3
−Nb2/3)O 3 , Pb(Mg1/3−Nb2/3)O 3 …
...etc. b Expressed by the general formula A 2+ (B1/2 2+ −B1/2 6+ )O 3 For example, Pb(Ni1/2−W1/2)
O 3 , Pb(Co1/2−W1/2)O 3 ...etc. c Expressed by the general formula A 2+ (B1/2 3+ −B1/2 5+ )O 3 For example, Pb(Fe1/2−Nb1 /2)
O 3 , Pb (Sb1/2−Nb1/2) O 3 , Pb (Y1/2
-Nb1/2)O 3 ... etc. (5) Solid solution centered on NaNbO 3 e.g.
NaNbO3 , (Na-K) NbO3 , Na(Ta-Nb)
O 3 ... etc. 2 Tungsten bronze structure For example, PbNb 2 O 6 , PbNb 2 O 6 −PbTa 2 O 6 ,
PbNb 2 O 6 −BaNb 2 O 6 ... etc. 3 Bismuth layered structure For example, Bi 4 Ti 3 O 12 , Bi 4 PbTi 4 O 15 ,
Bi 4 Sr 2 Ti 5 O 18 ... etc. 4 Others LiNbO 3 , LiTaO 3 ... etc. 5 Each of the above component systems is the basic composition, and a part of Pb is replaced with an alkaline earth metal 6 Each of the above component systems (including PbTiO 3 ) as a basic composition, and the following and one or more selected from each group are added as subcomponents,
Metamorphosed () Nb 2 O 5 , Ta 2 O 5 , La 2 O 3 , Sb 2 O 5 ,
Sb 2 O 3 , Bi 2 O 3 , WO 3 etc. () MgO, Fe 2 O 3 , Sc 2 O 3 , K 2 O etc. () Cr 2 O 3 , U 2 O 3 , MnO 2 etc. These various ferroelectrics The excellent ferroelectricity, piezoelectricity, and pyroelectricity inherent to each composition can be selected and utilized by changing the basic composition of the porcelain, and by substituting or adding subcomponents. At the same time, it is also possible to control the particle size, lower the coercive electric field to further improve electric field orientation, or conversely increase the coercive electric field to create a composite piezoelectric material that is resistant to static loads, and to stabilize changes over time. This makes it possible to obtain a composite piezoelectric material with width-oriented characteristics suitable for the intended use. Next, in the present invention, the polymeric substance that can be composited with the above-mentioned ferroelectric porcelain, especially the porcelain powder consisting of virtually single-domain microcrystals, includes various rubbers, namely natural, artificial, synthetic, and recycled rubbers. or blend rubbers thereof, especially fluorine rubber and chloroprene, and thermoplastic resins such as polyvinylidene fluoride (PVDF), acrylonitrile-butadiene-styrene copolymer (ABS),
Vinyl chloride (PVC), polyvinyl fluoride (PVF)
etc. The etching solution can be general acids,
An alkaline solution may be used, but care must be taken to only remove the desired irregular layer or amorphous layer, and to elute the Pb component of the crystalline layer to a point where the piezoelectricity is not impaired. Therefore, the lighter the concentration, the easier it is to process, but it takes a long time in a stationary state. However, by raising the temperature, for example, etching while boiling, or by adding stirring or slight pulverization even at room temperature, the time can be greatly shortened, and the etching time can be greatly reduced due to friction and abrasion between the particles. There is an advantage that the corners are further reduced and single crystal grains with a more rounded appearance can be obtained. Next, several examples of standard chemical etching treatment conditions are specifically shown in Table 1 below.
【表】
温度を上げれば、処理時間はさらに短縮可能と
なる。上記エツチング処理は強誘電性磁器粉末
100gに対してエツチング液100gとし上記のよう
な条件で行なうとよい。
以下この発明の実施例につき説明する。
強磁電性磁器の合成
市販の純度99%以上のPbOおよびWO3、98.5%
以上のZrO2、98%以上のTiO2を用い、つくろう
とするPb(Ti0.5−Zr0.5)O3+1重量%WO3の組
成になるよう配合し、その2.5Kgを秤取して振動
ミルにより乾式で5時間にわたつて混合した。こ
のとき振動ミルの内壁にウレタン樹脂内張をし、
アルミナ玉石を用いて不純物の侵入を防いだ。
この混合粉末を高アルミナ質るつぼに詰めPbO
の雰囲気中で730℃に4時間保持し、固相反応に
よつてPb(Ti0.5−Zr0.5)O3+1重量%WO3を合
成した。
粉砕工程
これより採取した200gの粉末にアセトンを加
え、2容積のアルミナ質ボールミルを用い300
gのアルミナ玉石によつて8時間にわたり粉砕し
た。(粉末(i))
アニール処理
この粉砕で得られた粉末iを乾燥した後、60メ
ツシユの篩にて粗粒を除き、小型のロータリーキ
ルンを用い酸素富化雰囲気または大気中、炉内温
度800〜950℃にて、毎回15分間の加熱アニール処
理を施した。
エツチング処理
次にエツチング液として試薬特級の氷酢酸に水
を容量比1:1の割合で加えた希釈液を用意し、
300mlのビーカーに加熱アニール処理後の粉末を
容量で100ml入れ次いで上記エツチング液を加え
全体で200mlとしたものにそれぞれ以下に示すエ
ツチング処理を施した。
まず、950℃で、O2を10/分(O2濃度38%)
供給して2回アニールした粉末でエツチング処理
条件を次の様に変えた粉末(a)〜(e)とエツチング条
件を粉末(b)と同一にしてアニール条件を変えた粉
末(f)、及び(g)を得た。
(a) マグネチツクスターラーによる8時間の撹拌
を伴う8時間のエツチング処理
(b) 8時間の撹拌とそのあと16時間の静置の計24
時間のエツチング処理
(c) 8時間の撹拌とそのあと40時間の静置の計48
時間のエツチング処理
(d) 8時間の撹拌のあと88時間静置の計96時間の
エツチング処理
また機械的な粉砕を含むエツチング処理とし
て、
(e) 500mlの樹脂製薬品瓶に上記アニール処理後
の粉末100gと18mmφ、150gのアルミナ玉石を
入れ、エツチング液を全体の容量が300mlにな
るように注入後密閉して100r.p.mの回転機に
かけ3時間のエツチング処理
(f) 800℃で酸素を2/分炉内に供給(C2濃度
27%)してアニールした粉末を粉末(b)と同一の
エツチング処理
(g) 950℃の大気中でアニールした粉末を粉末(b)
と同一のエツチング処理
上記各処理後の粉末を乾燥させ、粉末(a)、(b)、
(c)、(d)、(e)、(f)、(g)を得た。
なお比較例としてエツチング処理前すなわち加
熱アニール処理後の粉末(h)及び粉砕工程を経ただ
けの粉末(i)も用いた。
これらの各粉末(ただし粉末(c)、(f)及び(g)を除
く)の累積粒度分布を第1図に示す。測定は0.05
%ピロリン酸ナトリウム水溶液に分散して行なつ
た。同時に平均粒径を比表面積計によつて測定し
その結果は後掲の表3に示してある。
第1図で、注目すべき点は、粉砕した紛末をア
ニール処理すると、一旦粒度が粗くなり、それら
を各種エツチング処理により元に近づけたり、さ
らには軽い粉砕も加えれば元より細かくしている
点である。
これは、後述するが拡大写真観察で判明したと
ころであつて、加熱アニールにより微細粉末が凝
集して、二次粒子を形成するためである。アニー
ルにより不整化相の整化を実現できても、このよ
うに凝集した状態では、高分子との混合の際、均
一な分散が出来ず、ち密で高性能の複合圧電材料
が得られ難いことが予想される。
これらを粉砕してしまえば、ある程度個々の粒
子にもどるが、又粉砕による歪によつて圧電性が
そこなわれてしまう。
そこで、圧電性をそこなうことなく、個々の粒
子に分離するのに化学的エツチングが効果を発揮
するわけである。
一例として粉末(d)と(e)について走査型電子顕微
鏡写真図(倍率5000倍)をそれぞれ第2図a,b
に示すように、強誘電性磁器粉末粒子の融着した
二次粒子が撹拌とか軽度の機械的解砕を併用した
エツチング処理を加えることにより、一層適切に
単一結晶粒子に解離することが認められる。
またエツチング作用には二次粒子の解離のほか
に各粒子の表面を溶解する働きもあるため粒子径
はわずかずつ小さくなつていく。平均粒子径はエ
ツチング処理時間が長くなる程また機械的な外力
が強い程小さくなつていくこともわかる。
とくに回転ミル粉砕を併用したエツチング処理
により得られた粉末(e)では7μm以上の粒子は全
くなくなり、単一微粒子ないしは7μm以下の小
さな二次粒子に解離されている。このことは第2
図a,bを対比して観察すれば明らかである。
第1図に、粉末(i)とエツチング処理した粉末(a)
〜(e)との粒度分布を示すようにいずれのエツチン
グ処理においても、また、サブμm以下の極微細
粒子(粉砕粉末(i)では約10%含まれる)を溶解す
る作用も併せ持つており、この為複合材料とした
時の可塑性、流動性をよくし加工性を上げる効果
につながつていることもエツチング処理の見のが
せぬ効果である。
また、第3図は通常の合成−粉砕(16時間)工
程を経たNb添加チタン酸ジルコン酸鉛磁器粉末
の走査型電子顕微鏡写真図(倍率5000倍)である
が、このように機械的粉砕を施したままの粉末
は、ほとんどが機械的破砕による破砕片であるた
め総じて粒子破面がするどく刃先のようにシヤー
プになつている。従つてもしも柔軟性の高分子物
質との複合材料とした場合に該複合材料に外力が
働いて変更した際、シヤープな先端で高分子物質
を部分的に切断、穿設するなど機械的破壊を生じ
やすく、複合材料が硬くかつもろく機械的強度が
低くなる欠点を生じる原因となる。
これに対し上述した如く軽い機械粉砕を併用し
たエツチング処理は、単粒子を融着しているガラ
ス化した粒界に軽い機械的外力を加えることによ
り発生したクラツクを介してエツチング液を粒界
内部まで浸透させ酸に溶けやすいガラス相を溶か
して単一粒子に解離、分解させる粉化機構である
ため破砕片をほとんど含まないこと、また本質的
に化学的エツチングは先の尖つた所や鋭角な所を
優先的に溶解する働きがあるので丸味を持つ粒子
を得ることができるなどの大きな利点がある。
このため従来の圧電性磁器粉末でみられたよう
な欠点が大巾に改善され粉末が丸味を持つので機
械的強度が向上し、また高分子とのなじみがよく
粉末の充徹密度も上がり、空胞がなくなり、ち密
で且つ磁器粉末の高配合が可能となりその分複合
材料の圧電性能を増大させることができるように
なつた。
次にこれらの粉末の内部的な違いを、X線回折
にて調べたのが第4図a,bである。同図aに示
したこの発明による化学エツチング処理粉末(b)
は、同図bに示した対照粉砕粉末(i)と比べて、例
えば(200)のKβ線の半価幅がよりせまいピー
クを呈し、結晶格子が整然と揃つていて、乱れの
少ないことを示し結晶軸のそろつた単一分域の単
結晶に近い微結晶であることを示している。それ
ぞれの半価幅は粉末(b)0.170、粉末(i)0.315度であ
つた。
次にこれら粉末(b)と(i)を用い、それぞれ高分子
物質であるポリふつ化ビニリデン(PVDF)と、
3:2の容積割合の配合で混合したシート状の複
合材料の分域の電場配向性の違いとそれらの圧電
特性の相違について述べる。なお複合材料の製造
法については後述する。
これらの供試シートは、とくに950℃、O2雰囲
気(O2濃度38%)、2時間の加熱アニールを2回
行なつたのち撹拌8hr+静置16hr計24hr酢酸溶液
でエツチング処理した粉末(b)を用いたもの(表3
試料No.2)について、まずその片面における
(200)および(002)面のX線回折強度を測定
し、ついで両面にうすく銀蒸着電極を形成した上
で100℃シリコンオイル中にて150KV/cm、30分の
条件で分極を行なつたのちに再び(200)、および
(002)面のX線回折強度を測定した結果を第5図
aに、また対照粉砕粉末(i)を用いたもの(表3試
料No.9)について同様な測定を行なつた結果を
第5図bにそれぞれ示した。
これらの測定値に基いて分極前および分極後に
おけるC軸面のX線回折強度比I(200/I
(002)+I(200)をそれぞれ算出し、ついで分極
によつて電界方向に揃つた分域増加分を求めて第
2表に示した。なお両粉末(b)、(i)の(200)Kβ
の半価幅をあわせ示した。[Table] If the temperature is raised, the processing time can be further shortened. The above etching process is performed using ferroelectric porcelain powder.
It is preferable to use 100g of etching solution per 100g and perform the process under the conditions described above. Examples of the present invention will be described below. Synthesis of ferromagnetic porcelain Commercially available PbO and WO 3 with purity above 99%, 98.5%
Using the above ZrO 2 and TiO 2 of 98% or more , blend it so that it has a composition of Pb (Ti 0.5 − Zr 0.5 ) O 3 + 1% by weight WO 3 and weigh out 2.5 kg. The mixture was then dry mixed in a vibrating mill for 5 hours. At this time, the inner wall of the vibrating mill is lined with urethane resin,
Alumina boulders were used to prevent impurities from entering. This mixed powder was packed in a high alumina crucible and PbO
The mixture was maintained at 730° C. for 4 hours in an atmosphere of 100° C., and Pb(Ti 0.5 −Zr 0.5 )O 3 +1% by weight WO 3 was synthesized by solid phase reaction . Grinding process Add acetone to 200g of powder collected from this, and use a 2-volume alumina ball mill to crush 300g of powder.
milled for 8 hours with alumina boulder of 100 g. (Powder (i)) Annealing After drying the powder i obtained by this pulverization, coarse particles are removed using a 60-mesh sieve. Heat annealing treatment was performed at 950°C for 15 minutes each time. Etching process Next, prepare a diluted solution of reagent-grade glacial acetic acid and water at a volume ratio of 1:1 as an etching solution.
A 300 ml beaker was charged with a volume of 100 ml of the heat-annealed powder, and then the above etching solution was added to make a total of 200 ml, and each of the beakers was subjected to the etching treatment shown below. First, at 950℃, 10/min of O 2 (O 2 concentration 38%)
Powders (a) to (e) were supplied and annealed twice and the etching conditions were changed as follows; Powder (f) was the same as powder (b) but the annealing conditions were changed; and (g) was obtained. (a) 8 hours of etching treatment with 8 hours of stirring using a magnetic stirrer (b) 8 hours of stirring followed by 16 hours of standing for a total of 24 hours
Time etching treatment (c) 8 hours of stirring followed by 40 hours of standing for a total of 48 hours
Time etching treatment (d) Etching treatment for a total of 96 hours, including stirring for 8 hours and then standing for 88 hours. (e) Etching treatment including mechanical crushing. (e) After the above annealing treatment on a 500 ml resin pharmaceutical bottle Add 100g of powder and 150g of alumina cobbles of 18mmφ, inject the etching solution so that the total volume is 300ml, seal it, and apply it to a rotary machine at 100rpm for 3 hours of etching treatment (f) Oxygen is added at 800℃ for 2 hours. /Supplied into the blast furnace ( C2 concentration
27%) and annealed powder is subjected to the same etching treatment as powder (b) (g) Powder annealed in air at 950℃ is treated as powder (b)
The same etching treatment as above. After drying the powder after each treatment, powder (a), (b),
(c), (d), (e), (f), and (g) were obtained. As comparative examples, powder (h) before etching treatment, that is, after heat annealing treatment, and powder (i) which had just been subjected to a pulverization step were also used. The cumulative particle size distribution of each of these powders (excluding powders (c), (f), and (g)) is shown in Figure 1. Measurement is 0.05
% sodium pyrophosphate aqueous solution. At the same time, the average particle diameter was measured using a specific surface area meter, and the results are shown in Table 3 below. What is noteworthy in Figure 1 is that when the crushed powder is annealed, the particle size becomes coarser, and then various etching treatments can bring the particles closer to the original size, or even light pulverization can make them finer than the original size. It is a point. As will be described later, this was discovered through observation of enlarged photographs, and is because the fine powders aggregate due to heat annealing to form secondary particles. Even if it is possible to organize the irregular phase by annealing, in this aggregated state, uniform dispersion is not possible when mixed with polymers, making it difficult to obtain a dense and high-performance composite piezoelectric material. is expected. If these are pulverized, they will return to individual particles to some extent, but the piezoelectricity will be impaired due to the strain caused by the pulverization. Therefore, chemical etching is effective in separating the particles into individual particles without damaging the piezoelectric properties. As an example, scanning electron micrographs (magnification: 5000x) of powders (d) and (e) are shown in Figures 2a and b, respectively.
As shown in Figure 2, it was found that secondary particles of fused ferroelectric porcelain powder particles were more appropriately dissociated into single crystal particles by etching treatment combined with stirring and mild mechanical disintegration. It will be done. Furthermore, the etching action not only dissociates secondary particles but also dissolves the surface of each particle, so the particle size gradually decreases. It can also be seen that the average particle diameter becomes smaller as the etching treatment time becomes longer and as the mechanical external force becomes stronger. In particular, in the powder (e) obtained by etching treatment combined with rotary mill grinding, there are no particles larger than 7 μm, and the particles are dissociated into single fine particles or small secondary particles smaller than 7 μm. This is the second
This becomes clear if you compare and observe Figures a and b. Figure 1 shows powder (i) and etched powder (a).
As shown in the particle size distribution of ~(e), both etching treatments also have the effect of dissolving ultrafine particles of sub-μm or less (contained approximately 10% in crushed powder (i)). For this reason, one of the effects of etching treatment that cannot be overlooked is that it improves plasticity and fluidity when used as a composite material, leading to increased workability. Figure 3 is a scanning electron micrograph (magnification: 5,000x) of Nb-added lead zirconate titanate porcelain powder that has undergone the usual synthesis-pulverization process (16 hours); Most of the as-applied powder is fragments resulting from mechanical crushing, so the fractured surfaces of the particles are generally sharp, like the edge of a knife. Therefore, if a composite material is made with a flexible polymeric material and an external force is applied to the composite material and the material is changed, the sharp tip may partially cut or puncture the polymeric material, causing mechanical damage. This easily occurs and causes the disadvantage that the composite material is hard and brittle and has low mechanical strength. On the other hand, in the etching process that uses light mechanical pulverization as described above, the etching solution is applied to the inside of the grain boundaries through the cracks generated by applying a light mechanical force to the vitrified grain boundaries that fuse single particles. Because it is a powdering mechanism that penetrates up to the point where the glass phase is easily soluble in acids and dissociates and decomposes it into single particles, it contains almost no broken pieces. It has the great advantage of being able to obtain particles with roundness because it has the function of preferentially dissolving certain parts of the body. As a result, the drawbacks of conventional piezoelectric porcelain powders have been greatly improved, and the powder has a rounded appearance, which improves mechanical strength.It also blends well with polymers, increasing the packing density of the powder. Vacuoles are eliminated, making it possible to mix dense porcelain powder with a high content, thereby increasing the piezoelectric performance of the composite material. Next, the internal differences between these powders were investigated by X-ray diffraction, as shown in Figures 4a and 4b. Chemically etched powder according to the present invention shown in Figure a (b)
For example, compared to the control pulverized powder (i) shown in Figure b, the half-value width of the Kβ line of (200) exhibits a narrower peak, indicating that the crystal lattice is well-aligned and less disordered. This shows that it is a microcrystal close to a single crystal in a single domain with aligned crystal axes. The half width of each powder was 0.170 degrees for powder (b) and 0.315 degrees for powder (i). Next, using these powders (b) and (i), polyvinylidene fluoride (PVDF), which is a polymeric material, was added.
We will discuss the differences in electric field orientation in the domains of sheet-like composite materials mixed at a volume ratio of 3:2 and the differences in their piezoelectric properties. Note that the method for manufacturing the composite material will be described later. These test sheets were made into powders (b ) using (Table 3
For sample No. 2), first measure the X-ray diffraction intensity of the (200) and (002) planes on one side, then thinly deposited silver electrodes on both sides, and heat at 150KV/cm in silicone oil at 100℃. Figure 5a shows the results of measuring the X-ray diffraction intensity of the (200) and (002) planes again after polarization was carried out under the conditions of , 30 minutes, and the results using the control pulverized powder (i). Similar measurements were performed on Sample No. 9 in Table 3, and the results are shown in FIG. 5b. Based on these measured values, the X-ray diffraction intensity ratio I (200/I
(002)+I(200) was calculated, and then the domain increment aligned in the electric field direction due to polarization was determined and shown in Table 2. In addition, (200) Kβ of both powders (b) and (i)
The half-value width of is also shown.
【表】
一般に分極前にあつては、C軸方向が、X、Y
およびZ各座標軸方向に対して同一の確率で向く
筈であり、従つてシートの厚み方向に向く確率は
本来1/3≒0.33であるべきところ、両粉末の何れ
を用いた供試シートでも、それより低くなつてい
るのは、圧延のカレンダ形成の際に圧延面と平行
な方向に粉末粒子が配向したためと考えられる
が、何れにしても、加熱アニール粉末を用いたも
のは、分極の前後でX線回折強度比が0.25から
0.71へかわり、分極によつて電界方向への分域の
著大な配向が、増加分0.46において生じるのに反
し、対照粉砕粉末を用いたものでは、事実上、配
向の改善は生じていない。つまり粉砕により構造
破壊をおこし多分域化とか不整化した強誘電性磁
器粉末は、高分子物質に混合したときに、分域配
向性、すなわち分極性がそこなわれ、これが期待
の圧電性能の達成されない原因である。
次にこの発明の複合材料は、すでにのべた各磁
器粉末と高分子物としてたとえばポリふつ化ビニ
リデン(PVDF)とをそれぞれ3:2の容積割合
に配合し、溶剤としてアセトンを投入して混合し
溶剤の揮発後に170〜180℃に加熱してオーブンロ
ールで混練した後、厚み0.015〜0.05mmのフイル
ム及び厚み0.5mmのシート状に圧延し、幅100mm、
長さ150mmの方形に切り揃えて供試シートとし
た。
この時エツチング処理なしの粉末(h)は、第1図
の粒度分布で示されている通り粒径15μm以上の
粒子が末だ35%も残存しており、厚み0.025mmの
フイルム状に圧延した際いたる所にこの粗大粒子
による穿孔または該粒子の離脱による孔があくた
め上、下面の蒸着などによる電極間が短絡し、分
極が行なえず圧電性を付与することが不可能であ
り、この粉末(h)を利用するには厚みを倍の0.050
mm以上にする必要があつた。
しかしながら厚みを0.050mm以上にすると、フ
イルムが硬く、重くなり例えばヘツドホン、スピ
ーカー等の電気音響変換フイルムとか、応答性の
速い高感度の焦電性フイルムなどへは応用するこ
とができない。
これに対しエツチング処理または機械的な解砕
を加えながら施すエツチング処理は、融着した粗
大粒子を単一粒子に分離するとともに粒子の鋭い
個所を優先的に溶かして粒子に丸味を帯びさせる
ので0.015〜0.025mmの薄いフイルムに成形しても
ほとんど穴が生せず実用に耐えうる高性能圧電フ
イルムを製造することができた。
このうちとくに粉末(e)は7μm以上の粗大粒子
が皆無のため厚みを0.015mmと極く薄くしてもフ
イルムに穴を生せず成形可能であつた。このフイ
ルムの顕微鏡写真図(倍率225倍)を第6図aに
示すが、ピンホールもなく良好な表面が得られる
ことがわかる。これに対しエツチング処理なしの
粉末(h)を用いて成形したフイルムは同図bに示す
如く粗大粒子によるピンホールが多数見られる。
このように粉末(e)を用いたフイルムは樹脂のみの
フイルムの薄さに近いもので圧電性(d定数)が
それの2倍も大きい圧電性高分子複合材のフイル
ムが得られた。
次に得られた各フイルムの両面にうすく銀蒸着
電極を形成した上で100℃シリコンオイル中にて
150KV/cm、30分間の条件で分極を行なつた。
なお比較のため磁器粉末を含まないFVDF一軸
延伸フイルムを製造し、上記と同じ条件で分極を
行なつた。
進んで上記の各供試シートを幅20mm、長さ70mm
に切断し、1V、1KHzの万能ブリツジで静電容量
を測り、それにより比誘電率ε/ε0(ここにε
0=8.854×10-12F/m)を算出した。
また各試片に45gのおもりをつけ、それに40Hz
の正弦波を100V/mmで印加し、この際に生じる伸
びを差動トランスにて計測して圧電ひずみ定数
d31=t/V×Δl/l(m/V)を求め、これか
ら圧電出力定数g31=d31/ε0・ε(V・m/N)
を求め表3の成績を得た。
なお上記圧電定数の計算式において、tは圧電
シートの厚み(m)、Vは印加電圧(V)、lは圧
電シートの長さ(m)、Δlは電圧印加による長
さ方向の伸び(m)である。[Table] Generally, before polarization, the C-axis direction is
and Z should be oriented with the same probability in the direction of each coordinate axis, and therefore the probability of oriented in the thickness direction of the sheet should be 1/3≒0.33, but for the test sheet using either of the two powders, The reason why it is lower than that is thought to be because the powder particles were oriented in the direction parallel to the rolling surface during calendering during rolling, but in any case, the powder using heat-annealed powder is lower before and after polarization. The X-ray diffraction intensity ratio starts from 0.25.
0.71, the polarization causes a significant orientation of the domains in the direction of the electric field at an increment of 0.46, whereas with the control milled powder virtually no improvement in orientation occurs. In other words, when ferroelectric porcelain powder whose structure has been destroyed by crushing and has become multi-domain or irregular, when mixed with a polymer material, the dot-domain orientation, that is, polarization, is impaired, and this results in the achievement of the expected piezoelectric performance. This is the reason why it is not done. Next, the composite material of the present invention is prepared by mixing each of the previously applied porcelain powders and a polymer such as polyvinylidene fluoride (PVDF) at a volume ratio of 3:2, and adding acetone as a solvent. After the solvent has evaporated, the mixture is heated to 170-180℃ and kneaded with oven rolls, then rolled into a film with a thickness of 0.015-0.05mm and a sheet with a thickness of 0.5mm, with a width of 100mm.
The sample sheet was cut into squares with a length of 150 mm. As shown in the particle size distribution in Figure 1, the powder (h) without etching treatment had 35% remaining particles with a particle size of 15 μm or more, and was rolled into a film with a thickness of 0.025 mm. Since holes are formed everywhere due to the coarse particles or the separation of the particles, short circuits occur between the electrodes due to vapor deposition on the upper and lower surfaces, making it impossible to polarize and impart piezoelectricity. To use (h), double the thickness to 0.050
It was necessary to make it more than mm. However, if the thickness is 0.050 mm or more, the film becomes hard and heavy and cannot be applied to, for example, electroacoustic conversion films for headphone and speakers, or high-sensitivity pyroelectric films with quick response. On the other hand, etching treatment or etching treatment performed while adding mechanical crushing separates the fused coarse particles into single particles and preferentially melts the sharp parts of the particles to make the particles rounded. Even when formed into a thin film of ~0.025 mm, there are almost no holes, and we were able to produce a high-performance piezoelectric film that can withstand practical use. Among these, powder (e) in particular had no coarse particles of 7 μm or more, so it could be molded into a film without forming holes even if the thickness was made as thin as 0.015 mm. A micrograph of this film (225x magnification) is shown in Figure 6a, and it can be seen that a good surface with no pinholes was obtained. On the other hand, in the film molded using the powder (h) without etching treatment, many pinholes due to coarse particles are observed, as shown in Figure b.
In this way, the film using powder (e) was close to the thinness of the film made only of resin, and the piezoelectric polymer composite film was obtained which had piezoelectricity (d constant) twice as large as that of the film made only of resin. Next, thin silver vapor-deposited electrodes were formed on both sides of each film, and the film was placed in silicone oil at 100°C.
Polarization was performed at 150 KV/cm for 30 minutes. For comparison, an FVDF uniaxially stretched film containing no porcelain powder was produced and polarized under the same conditions as above. Proceed to each test sheet above with a width of 20 mm and a length of 70 mm.
The capacitance was measured using a 1V, 1KHz universal bridge, and the relative dielectric constant ε/ε 0 (where ε
0 = 8.854×10 -12 F/m). In addition, a 45g weight was attached to each specimen, and a 40Hz
A sine wave of 100V/mm is applied, and the elongation that occurs at this time is measured using a differential transformer to determine the piezoelectric strain constant.
Find d 31 = t/V x Δl/l (m/V), and from this calculate the piezoelectric output constant g 31 = d 31 /ε 0・ε(V・m/N)
The results shown in Table 3 were obtained. In the above formula for calculating the piezoelectric constant, t is the thickness of the piezoelectric sheet (m), V is the applied voltage (V), l is the length of the piezoelectric sheet (m), and Δl is the elongation in the length direction due to voltage application (m). ).
【表】
この結果、圧電性のうちd定数で述べると、エ
ツチングの際の条件たとえばエツチング時間とか
外力条件を適切り選べば、実施例の粉末(b)を用い
たときのように圧電性を大きく向上させることが
できる。
また静止エツチング処理時間を長くすれば、不
純物とか格子欠陥とか不定形層(ガラス相)など
の集積している層がとれるのみならず、粒子表面
が溶けて粒子がわずかずつ小さくなつていくにつ
れ尖つた部分がなくなり丸味を帯びてくるので高
分子と複合化するのにより適した粉末となる。
たとえば撹拌8時間のみの粉末(a)とその後88時
監静置エツチング処理を施した粉末(d)とを比較し
てみると、第1図より明らかなように全体の各粒
子が少しづつ小さくなつて平均粒径が1.8μm→
1.7μmとなつており、また複合材料の圧電定数
d値は静置時間なしのものよりわずかであるが向
上しているとおり、適切なエツチング処理を施し
た磁器粉末を用いると複合材料の性能は向上す
る。
ただし磁器粉末のエツチング処理液としては、
高分子物質と複合後の材料の性能に悪影響を与え
ない溶液を使用するため、ときとしてはエツチン
グ液に浸すだけでは凝集、融着した二次粒子を解
離、分離することが困難な場合があるが、このよ
うな場合には機械的な外力を補助的に加えれば容
易に解離する。
たとえば粉末(e)は、エツチング液に浸しながら
回転ミルで3時間粉砕した場合であるが、まだ一
部融着二次粒子が残存しているものの、7μm以
上の大きな粒子は皆無でありそのほとんどが単一
粒子に解離し従つて第1図に示す如く粒径の揃つ
た優れた粉末が得られる。
ただしエツチング処理に際して機械的粉砕を併
用すると結晶の多分域化、不整化がさけられず粉
砕の程度に応じて圧電性能の劣化が生じるため、
機械的粉砕の併用に当つては適切な粉砕条件を選
び軽度にとどめることが肝要である。
このようにして得られた粉末は、従来の粉砕、
粉砕粉末のような鋭い刃先のような破面とか、と
がつた角がないので、高分子との混合状態がより
ち密になり空胞の少ない複合材料が得られるた
め、高性能圧電材料になるとともに機械的強度も
大巾に向上し例えば、次に述べるような繰返し衝
撃応力に対しても機械的損傷がなく機械電気変換
体として、実用に耐える材料に改質することが可
能となつた。
次に上記実施例に係る圧電性高分子複合シート
No.2と従来品の圧電シートNo.9とを第7図に示
す繰り返し荷重に対する耐久実験をし、その結果
を第8図のグラフに示す。
実験方法
第7図に示すように上記圧電シートNo.2及び
従来品の圧電シートNo.9について1cm平方で厚
さ0.5mmの試料2とし、これらを基台3と緩衝用
鋼板4(塩化ビニル板厚さ1mm)との間に挾み、
重さ11.8gの鋼球1を10cmの高さから繰り返し落
下させ試料の出力電圧をシンクロスコープ5で測
定した。各10枚の試料の平均値を第8図のグラフ
に示す。
第8図のグラフに示す如く、従来品No.9は平
均70万回で破損したが、本発明の圧電シート
No.2は全て300万回の繰り返し荷重を加えた後も
正常に作動し且つ出力電圧の劣化も見られなかつ
た。
以上述べたようにこの発明によれば、強誘電性
磁器のもつ高い圧電特性と、高分子物質の柔軟性
とを合わせ持つ文字通りの圧電性高分子複合材料
を実現することができる。[Table] As a result, in terms of the d constant of piezoelectricity, if the etching conditions such as etching time and external force conditions are appropriately selected, piezoelectricity can be improved as when using powder (b) in Example. It can be greatly improved. Furthermore, if the static etching time is increased, not only will accumulated layers such as impurities, lattice defects, and irregularly shaped layers (glass phase) be removed, but also the particles will become sharper as the particle surface melts and the particles become smaller little by little. Since the vines disappear and the powder becomes more rounded, it becomes a powder that is more suitable for compounding with polymers. For example, when comparing powder (a) that has been stirred for 8 hours only and powder (d) that has been subjected to 88 hours of supervised etching treatment, it is clear from Figure 1 that each particle is gradually smaller. The average particle size is 1.8μm→
1.7 μm, and the piezoelectric constant d value of the composite material is slightly improved compared to the one without standing time, so using porcelain powder that has been properly etched can improve the performance of the composite material. improves. However, as an etching solution for porcelain powder,
In order to use a solution that does not adversely affect the performance of the polymer substance and the composite material, it may sometimes be difficult to dissociate and separate the aggregated and fused secondary particles simply by immersing them in the etching solution. However, in such a case, if an external mechanical force is applied as an auxiliary force, they can be easily dissociated. For example, powder (e) was ground in a rotary mill for 3 hours while immersed in an etching solution. Although some fused secondary particles still remained, there were no particles larger than 7 μm, and most of them were not. The particles are dissociated into single particles, and an excellent powder with a uniform particle size as shown in FIG. 1 is obtained. However, if mechanical pulverization is used in combination with etching, multi-regionalization and irregularity of the crystals will be avoided, resulting in deterioration of piezoelectric performance depending on the degree of pulverization.
When using mechanical grinding in combination, it is important to select appropriate grinding conditions and keep the grinding conditions mild. The powder thus obtained can be processed by conventional grinding,
Since there are no sharp edges or sharp edges found in pulverized powder, the mixture with the polymer becomes more dense and a composite material with fewer vacuoles is obtained, making it a high-performance piezoelectric material. At the same time, the mechanical strength has also been greatly improved, and it has become possible to modify the material into a material that can withstand practical use as a mechanical and electrical transducer without mechanical damage even under repeated impact stress as described below. Next, the piezoelectric polymer composite sheet according to the above example
Durability tests were conducted on No. 2 and the conventional piezoelectric sheet No. 9 against the repeated loads shown in FIG. 7, and the results are shown in the graph of FIG. Experimental method As shown in Fig. 7, samples 2 of 1 cm square and 0.5 mm thick are used for the piezoelectric sheet No. 2 and the conventional piezoelectric sheet No. 9, and these are attached to a base 3 and a buffer steel plate 4 (PVC sandwiched between the plate (thickness 1 mm),
A steel ball 1 weighing 11.8 g was repeatedly dropped from a height of 10 cm, and the output voltage of the sample was measured using a synchroscope 5. The average value of each 10 samples is shown in the graph of FIG. As shown in the graph of Figure 8, conventional product No. 9 broke after an average of 700,000 cycles, but the piezoelectric sheet of the present invention
All No. 2 products operated normally even after 3 million repeated loadings, and no deterioration in output voltage was observed. As described above, according to the present invention, it is possible to realize a piezoelectric polymer composite material that has both the high piezoelectric properties of ferroelectric ceramics and the flexibility of polymer materials.
第1図はこの発明による単一分域微結晶よりな
る強誘電性磁器粉末とエツチング処理を省いた場
合の磁器粉末及び通常粉砕粉末との粒度分布比較
図、第2図a,bはそれぞれこの発明により得ら
れた強誘電性磁器粉末(d)、(e)、そして第3図は通
常の合成−粉砕法により得られたチタン酸ジルコ
ン酸鉛磁器粉末のそれぞれの走査型電子顕微鏡写
真図(倍率5000倍)、第4図a,bはこの発明に
よる磁器粉末(b)と在来の対照粉砕粉末(i)のX線回
折図、第5図a,bはこれらの両粉末(b)、(i)それ
ぞれの高分子材料との複合の際におけるC軸面の
X線回折強度の分極前後に於ける変化を示すX線
回折図、第6図a,bはエツチング処理を施した
磁器粉末および施さない磁器粉末を用いた各複合
材料の表面性状を比較した顕微鏡写真図(倍率
225倍)、第7図はこの発明による圧電ゴムシート
の耐久実験方法を示す図、第8図は圧電ゴムシー
トの耐久実験の結果を示すグラフである。
1……鋼球、2……圧電シート、3……基台、
4……緩衝用鋼板、5……シンクロスコープ。
Figure 1 is a particle size distribution comparison diagram of the ferroelectric porcelain powder made of single-domain microcrystals according to the present invention, the porcelain powder when etching treatment is omitted, and the normally pulverized powder. Fig. 3 shows scanning electron micrographs of ferroelectric porcelain powders (d) and (e) obtained by the present invention, and lead zirconate titanate porcelain powder obtained by a conventional synthesis-pulverization method ( Figures 4a and b are the X-ray diffraction diagrams of the porcelain powder according to the present invention (b) and the conventional control powder (i), and Figures 5a and b are the X-ray diffraction diagrams of both these powders (b). , (i) X-ray diffraction diagram showing the change in the X-ray diffraction intensity of the C-axis plane before and after polarization when composited with each polymeric material. Micrograph diagram comparing the surface properties of each composite material using powder and untreated porcelain powder (magnification
225 times), FIG. 7 is a diagram showing a durability test method for a piezoelectric rubber sheet according to the present invention, and FIG. 8 is a graph showing the results of a durability test for a piezoelectric rubber sheet. 1... steel ball, 2... piezoelectric sheet, 3... base,
4...Buffer steel plate, 5...Synchroscope.
Claims (1)
を介した固相反応による合成と、その粉砕および
加熱アニール処理ならびに化学的エツチング処理
を経て粒径の揃つた、実質的に単一分域微結晶よ
りなる強誘電性磁器粉末と高分子物質との混合物
から成ることを特徴とする圧電性高分子複合材
料。 2 所定の化学組成に応じる配合原料粉末の混合
を介した固相反応による合成と、その粉砕および
加熱アニール処理ならびに機械的な解砕、又は軽
度の粉砕を含む化学的エツチング処理を経て粒径
の揃つた、実質的に単一分域微結晶よりなる強誘
電性磁器粉末と高分子物質との混合物から成るこ
とを特徴とする圧電性高分子複合材料。[Claims] 1. Synthesis by solid-phase reaction through mixing of blended raw material powders according to a predetermined chemical composition, pulverization, heat annealing treatment, and chemical etching treatment to produce particles with substantially uniform particle size. A piezoelectric polymer composite material comprising a mixture of ferroelectric porcelain powder consisting of single-domain microcrystals and a polymer substance. 2 Synthesis by solid-phase reaction through mixing raw material powders according to a predetermined chemical composition, and particle size reduction through pulverization and heat annealing treatment, mechanical crushing, or chemical etching treatment including light pulverization. 1. A piezoelectric polymer composite material comprising a mixture of a ferroelectric porcelain powder consisting of substantially single-domain microcrystals and a polymeric substance.
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP1870279A JPS55111183A (en) | 1979-02-20 | 1979-02-20 | Piezoelectric high-molecular compound material |
DE2922260A DE2922260C2 (en) | 1978-06-01 | 1979-05-31 | Process for the production of piezoelectric composite materials with microcrystals with particularly good polarizability |
US06/722,199 US4675123A (en) | 1979-01-17 | 1985-04-11 | Piezoelectric composite material |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP1870279A JPS55111183A (en) | 1979-02-20 | 1979-02-20 | Piezoelectric high-molecular compound material |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS55111183A JPS55111183A (en) | 1980-08-27 |
JPS6125229B2 true JPS6125229B2 (en) | 1986-06-14 |
Family
ID=11978963
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP1870279A Granted JPS55111183A (en) | 1978-06-01 | 1979-02-20 | Piezoelectric high-molecular compound material |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS55111183A (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CA1236246A (en) * | 1981-09-09 | 1988-05-03 | Raychem Corporation | Electrically conductive polyvinylidene fluoride compositions |
-
1979
- 1979-02-20 JP JP1870279A patent/JPS55111183A/en active Granted
Also Published As
Publication number | Publication date |
---|---|
JPS55111183A (en) | 1980-08-27 |
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