JPS58190871A - Piezoelectric ceramic composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to Pb (In 31 Nb %) 133
1'bZr On l'b'rt t)1-(LiL
a) y2'l'i03 (LiBi), y6Ti03
The present invention relates to a piezoelectric ceramic composition containing Y as a basic component.

Already Pb (M gp Nbz) Om P b'r
A piezoelectric ceramic composition of the 10s type is known, but it has a radial electromechanical coupling coefficient (Kp) of 60% and a specific dielectric constant (ε
``) has a very superior piezoelectric custom-made unit of 3000,
Because the sintering temperature is as high as 200 to 1300℃, the amount of PbO evaporated is large (it is necessary to add lead to excess fRl when blending raw materials, or to sinter in a lead atmosphere, causing problems in reproducibility. there were.

Also, you already know)'b (Zn y, to bg
)0. -)'bTi03-PbZr01 piezoelectric porcelain composition was heated to PB at a firing temperature Y of 1200°C or lower.
Evaporation of o: tY: small (can be done, and the radial electrical a-mechanical coupling coefficient (Kp) as piezoelectric %Note) is 40 to 70
You can get as high as %. However, the dielectric constant (
It has a drawback Y that sr) is as low as about 2000.

Therefore, one object of the present invention is to obtain a radial electromechanical coupling coefficient (
The object of the present invention is to provide a porcelain composition having a pressure Kp) of 40% or more, a relative dielectric constant (sr) of 2800 or more, and a sintering temperature of 1200°C or less.

The first invention of the present application to achieve the above objective Y,
X・[a-1'b(Zn 7.Nb7.)01-b-P
bl'i0. - c・PbZr0. ]-Y-tL
iLa)>,'l'1011-Z-(LiB1
) 2TiO, (However, the above X, Y, Z, a, b,
The value of c is +1.08≦X≦ as X+Y +Z= ]
0.96, 0.02≦Y≦0. i 0 , 0.02≦
Z≦0.10. 0,10≦a≦0 as a+b+c=1
．． 50, 0.10≦b≦Sail65.0, JO≦C≦0.
80), acid fhiniobium (N
bt06 ) or antimony oxide (Sb.

0, ) or a mixture of these components is 0.3% by weight
~3. The present invention relates to a piezoelectric ceramic composition in which OM is added in a range of %.

According to the above invention, the radial electromechanical coupling coefficient (Kp)
is 45-66%, and the relative index [allS (sr) is 2800-
A piezoelectric buzzer and piezoelectric tweeter (speaker) similar to the former conventional composition described above were obtained.
, it becomes possible to obtain piezoelectric porcelain that is optimal for use as an electro-mechanical transducer element such as a pickup. It is now possible to set the sintering temperature in the range of 1100 to 90°C, and as with the latter conventional composition mentioned above, piezoelectric ceramics can be produced with good reproducibility and excellent industrial productivity. It becomes possible to obtain.

The second invention of the present application is a #2 ROM.

and a piezoelectric ceramic composition VC characterized by the addition of aluminum oxide Y. In this way, when chromium oxide and aluminum oxide are added, crystal grains become smaller and grain boundary strength is significantly improved.

An embodiment according to the present invention will be described below.

Lol/M example] When preparing the sample, the main components l'b (Zn) and Nh
y, )01- r'b'rio, l'bZrO
, , (1 tears, a) ), Ti01. (L group 1) 7Tt
U, Y, Son, and Calcined in the following manner. Pb (Zn
y.

Nby, ) 0. -1'b'l'i0. -)'bZ
For ro, FbO, N
b, 0. , ZnO,'l'i0. , ZrO.

were weighed and mixed by pulverization in a ball mill, and the mixed powder was calcined at 800°C and pulverized again. (LiLa)y
For 'lt OH, Li2C0, LaxOs, '1' I Otk were weighed so as to have a predetermined composition, pulverized and mixed in a ball mill, and the mixed powder bed was
Calcinate at 00℃.

Shattered again. For (LiB1) containing TiO,
7gr fixed set Etvc rfb [ic bi, Co,,
bi2o, TtO3;v were weighed, and the powder was ground and mixed in a ball mill, and the mixed powder was calcined at 700° C. and then ground.

Next, the above calcined Pb (Nb% containing Zn) 01 Pb
'l'101- l'bZr03. , (LiLa
1,61'iU, , (Litlj)pl"jO,
and Hesu.

1000 kg of O3 was weighed to have the composition shown in Tables 1 to 22, and the ingredients were ground and mixed in a ball mill.
/cm'' pressure and fired at various firing temperatures within the range of 1100 - 90°C.
A disk-shaped porcelain with a thickness of 0.4 mm and a wall thickness of 0.4 mm was completed. Silver electrodes were baked onto both main surfaces of this disc-shaped porcelain, and polarization treatment was performed by applying a DC voltage of 3 Kv/mm for about 1 hour in silicone oil at 120°C. Using this as a sample, Kp-ε''.

I asked for F'l'7. The electromechanical coupling coefficient (Kp) is I
) The number of mutual losses θ and the anti-common frequency were measured using a tE stretching circuit, and were determined by iI′t′II#. The relative permittivity (ε') was measured 24 hours after polarization using ktlz. In addition, a, b, c, X, Y, and Z in the valley table below are as follows:
It is a generated part. X [a-PI) (Zn y, N
bz) 0. - b -PbTi0s-c ・PbZ
r0. ] -Y (1, iLa), qTiO, -Z
t Li Llj )z'l'fO, the mole fraction X+Y+Z=3. This is the valley value of a+b+c=1. Furthermore, since the values of a, b, and c are the same in the valley table, they are shown in the main component column. Also, Nb, 0. is expressed as sub-it% n relative to the main component.

As is clear from the above Tables 1 to 17, the main components X-Y, Z, a-b, cYO-80≦X≦0.96,
0.02≦Y≦0.10.0.02≦Z≦0. 】Olo
, 10≦a≦0.50, 0.10≦b≦0.65%
(Within the range of 1,10≦C≦0,80, if the content is from 0.5% to 3.0% of production amount based on the main component of acid 1r9 niobium, the mechanical coupling coefficient (Kp) ,
Even custom-made ceramics with specific dielectric constants (εr) exceeding the acceptance criteria of the present invention can be obtained, making it possible to obtain porcelain plates useful for acoustic conversion elements such as piezoelectric buzzers and piezoelectric speakers. In particular, in sample numbers H-9, 14, 2], 23 and their vicinity, the relative dielectric constant (ε'') is 5000, and the mechanical coupling coefficient (Kp
) also exhibits 60% or more, and is suitable as an acoustic transducer. In addition, X, Y, and Z are good! The correct range is the explanatory 3 in Figure 1.
The preferred range of 7Cabb,c is shown by the original diagram and is shown by the ternary diagram of FIG.

In addition, in this composition range, the firing temperature is 1100 ~]
] Because it is sintered at a relatively low temperature of 90°C, the amount of lead evaporation is small (there is no variation in electrical percentage during violet production, and industrially superior porcelain can be obtained.

Mountain La) g 'l' t OH and Mountain 14 i) 7
'1' When 40B is 0.02 mol% or less, a material with large mechanical coupling coefficient (Kp) and relative dielectric constant (ε') is produced.Also, (LiLa)hTie is 0
．． When 10 mol%7]l- exceeds, the mechanical coupling coefficient (Kp) becomes 30% below -(LIIJI) When 1.4T10g exceeds 0.10 mol%, the relative dielectric constant (εr) becomes 200.
It becomes 0 or less.

Not suitable as an electroacoustic transducer. ftaX component composition [a
-1'b [Zn 3Nb5y, ) Ol-b-)
'bTiO,-c-PbZr01] in a,
When b and c are outside the above range.

Kp is 30% or less, and the practicality is poor, or the sinterability is very poor, and the industrial value is low. Furthermore, improvements in εr and Kp were observed with the addition of niobium oxide.
However, if the amount added is less than 3% by weight of the sail.

Since the effect of addition is not observed and the coercive electric field (Ec) is high, polarization treatment is difficult, and porcelain with high relative permittivity (ε'') and electromechanical coupling coefficient (Kp) cannot be obtained. 1
The amount of Hiniobium added is 3. θ weight, i′% is expected.

Insulation resistance decreases, polarization processing becomes difficult, Kp decreases, and it is not practical. Therefore, in the present invention, the content of niobium oxide is preferably in the range of 0.3% by weight or more and 3.01% by weight or less based on the main components.

Example 2 Pre-calcined product)'b (Zny, Nb5
s) 0n-Pbl'i0. -1'bZrO,, (I
A) gi'j03, tLiH lower Tj03, and the additive components Sb, O, and N were weighed as shown in Tables 23 to 26, and a disk-shaped sample was prepared in the same manner as in Example]. and after polarization, the electromechanical coupling coefficient (Kp).

When the relative dielectric constant (ε') was measured, Tables 23 to 26
The results in the table were obtained. Furthermore, a, b, c, and X.

Y and Z indicate the same thing as [Example].

As is clear from Tables 23 to 26, X, Y, Z,
a, b, c are 0.80≦X≦0.96, 0.02≦
Y≦0.10, 0.02≦Z≦(1,10,0,10
≦a≦0.50, sail] 0≦b≦0.65, sail] 0≦C
≦ Antimony oxide 0 for main components within the range of 80
．． In the samples containing 3.0 t% to 3.0 t%.

The mechanical coupling coefficient (Kp) and the relative dielectric constant (rr) both have satisfactory values. Therefore, it is useful for acoustic conversion elements such as piezoelectric buzzers and piezoelectric speakers.

In particular, sample numbers 2-33 to 2-36 have a relative dielectric constant (ε'')
is 4000 JaJ soil, and at the same time the mechanical coupling coefficient (Kp)
60% or more, making it suitable as an acoustic transducer. In addition, in this composition range, the firing temperature is from ]100 to ]1
Since sintering occurs even at a relatively low temperature of 90°C, there is no amount of lead evaporation, and even in N-title poems, the production of electrically weighted C (Sainote has ´ ゞratsuki; rr < , is good. To the east) The addition of antimony oxide increases the electromechanical coupling coefficient (Kp
), an improvement in the specific permittivity (ε') was observed, but if the amount added was less than 0.3 it%, no effect of addition was seen,
Because the coercive electric field (Etc) is high, it is difficult to perform a single polarization process, and it is impossible to obtain a porcelain with a large dielectric constant (ε') and electromechanical coupling coefficient (i<p).Furthermore, the amount of antimony added is 3
．． If it exceeds 0% by weight, the insulation resistance will decrease and polarization treatment will become difficult, and 1(p will decrease and it will not be useful. Therefore, the government-owned grave of antimony oxide is 0.37% by weight or more based on the generated content. .0] B: The range below % is preferable.

Actual IM example 3 Ph (Zn) and Nb5 as pre-calcined products
'i) 0s-Pb'l'i0. - PbZr0. −
(LllJa)7.1'i0. , (LiUi)
zl'io, and Nbρσ, Sb, 0 as additional components
1y Table 27 (Weighed so as to have the composition shown in Tables 411 to 32, Example) A disk-shaped sample was prepared and after polarization.

When the electromechanical coupling coefficient (Kp) and relative dielectric constant (rr) Y were measured, the results shown in Tables 27 to 32 were obtained.

Table (Main component composition Y X [a-1'
b (Zny.

Nb7)0. -b-PbTi0. -c-PbZrO
, ] -Y (Li La ) 7'rho.

-Z (L group 1) z'l'i0. Then, X+Y+Z=1. a
When expressed as +b + C = 1, as is clear from Tables 27 to 32, %X, Y, Z%a%b, c are sails 80≦X≦
0.96, 0.02≦Y≦0.1 (1,0,02≦
Z≦Sail] 0.0.10≦a≦0.50, 0.10≦b
For principal components within the range of ≦0.65°0.10≦C≦0.80.

Two mixed acids of niobium oxide% antimony oxide were reduced to 0.
In the sample containing 3.0% by weight from 331%, the mechanical coupling coefficient (Kpl) and relative permittivity (Cr) of
The value of is also satisfactory. Therefore, it is useful for acoustic conversion elements such as piezoelectric buzzers and piezoelectric speakers. Especially in sample number 3-17.3-18 and its vicinity, the relative dielectric potential is 1.
! ratio (Cr) is 5000, and at the same time the mechanical coupling coefficient (Kp
) is also 60% or more, which is suitable as an acoustic transducer. In addition, in this composition range, the firing temperature is 】】00~
]] It is relatively low at 90'C (even though it is sintered, the amount of lead evaporation is small (, even in Sumidai Poetry, there is little variation in electrical custom orders.

Furthermore, by adding both hyantemon acid and niobium oxide, improvements in the electromechanical coupling coefficient (Kp) and dielectric constant (ε'') were observed, but the total amount added was
If the amount is less than %, the effect of addition will not be seen, and the coercive electric field (Ec) will be insufficient, making polarization processing difficult and making it impossible to obtain porcelain with high specific @ electrical conductivity (Cr) and electromechanical coupling coefficient (Kp). No.

Furthermore, the total added weight of acid f hyantimony and niobium oxide is 3
．． If it exceeds 0% by weight, the insulation resistance will decrease, making it difficult to perform one polarization process, and the Kp will decrease, making it impractical. Therefore, M.H.
``Fit content of the sum of the two components (niobium and antimony oxide) (mixed component) is 0.3% by weight or more with respect to the main component 3.1
) A range of 11% or less is preferable.

Incidentally, instead of the sample preparation method in Examples 1 to 3, PbO and Nb were added to the compositions shown in Tables 1 to 32.

06, ZnO,'l'i0. ．． ZrO,,IJi,C
O,,Bit01%Sb,U,'y were weighed, ground and mixed in a ball mill, and this mixed powder was calcined at 800℃ and crushed to a pressure of 000 kg/cm''. The same results as above were obtained using a method of molding and firing one piece.

Example 4 Pre-calcined P b (ln,”s
Nb y, )-PbTs03 PbZr0,1.
(LtLa)T'+0. , (Li Hi )Ti(
For J3 iC, Nb as a subcomponent, 0. and sb
, oj, and Vc% chromium oxide (Crρj) and aluminum oxide (AI, 0.) were added to the compositions shown in Tables 33 to 48, and a disk-shaped sample was prepared in the same manner as in [Example]. After fabricating and polarizing this fL, the electromechanical coupling coefficient IK
p), relative dielectric constant (εr)Y was measured, Table 33~
The results shown in Table 48 were obtained. At the same time, in order to obtain a sample for measuring bending strength (σ), % 1000 kg/c
m'' pressure molding to form a square plate sound with a vertical width of 10 mm, a horizontal width of m2 omm, and a thickness of 5 mm, and the fL is 1100~]90
It was fired at a firing temperature within the range of 'C. After firing, bake silver electrodes on both sides, 3 KV/ in silicone oil at 20℃.
Polarization treatment was performed by applying a DC voltage of 1.5 mm to about 1 hour.

Next, based on the principle described in Tlc, page 3 of ``Ceramic Dielectric Engineering'' by Shin Okazaki, for example, the fracture strength is lengthened using a commercially available bending g1 degree measuring device fjt, and the quadratic formula is The bending strength was calculated by

However, σ is the transverse rupture strength %I'm is the maximum breaking load (kg).

t is the thickness + mm), I is the distance between the supporting points (mm), and w is the width of the sample (mm).

Furthermore, since the composition of the sample for measuring εr and I(p Y and the sample for measuring σ are the same, the same sample number is assigned and the measurement results of ε', Kp, and σ are shown in the 33rd sample. table~
Table 48 K summarizes. Furthermore, Tables 33 to 48 do not indicate firing temperatures.

For sample numbers 4-j to 4-42] ] 50'0.4-4
3-4-63]] 30'C, 4-64-4-80
]]70℃, 4-8] ~4-97te]] 5
0'0.4-98 to 4-134]]]70'C14-
315~4-]3]]50℃%4-336~4-15
6 ~ J] 80°C.

As is clear from Tables 33 to 48, chromium oxide is 0.10% by weight or less, aluminum oxide is 5.00% by weight or less, aluminum oxide is o-1Oi! fi% or more 2.00 '1ff
The electromechanical coupling coefficient (Np) and relative dielectric constant (
It becomes possible to improve the mechanical bending strength (σ) by 50% or more while maintaining the value of εr) within a practical range.

It has been found that this is because when acid 1r chromium and acid f hyaluminum chromium are added at the same time, the crystal grains of the porcelain become smaller and the grain boundary strength is significantly improved. This improvement in mechanical strength41 significantly reduces mechanical damage during the manufacturing process, reducing pressure! It has become fully compatible with the thinning of porcelain ceramics. The amount of acid f hyflom and aluminum oxide added is the main factor.]
If it is less than 0% by weight, the effect of improving mechanical bending strength is insufficient and there is no significant difference from the case where it is not added. If the amount of added chromium oxide exceeds 5.00 m1'%,! Air-mechanical coupling coefficient (
Kp) and specific n11 ratio (εr) decrease, and when the acid ratio aluminum added layer exceeds 2.0% by weight, the electromechanical coupling coefficient (kp+) and mechanical bending strength decrease.

6 Therefore, it is desirable to simultaneously add acid 11"chromium in a range of 0.10% to 5.00tii% and aluminum acid in a range of 0.10% to 2.001m% by weight. .

[Brief explanation of the drawing]

FIG. 1 is a ternary diagram showing the range of x, y, and z. FIG. 2 is a ternary diagram for showing the B, h, CI) ranges. In the symbols used in the drawings, X, Y. Z, a, b, and c indicate the composition of the main components. Procedural amendment (spontaneous) June 17, 1980 Patent Application No. 73180 2, Title of invention: Piezoelectric porcelain composition 3, Relationship with the person making the amendment: Applicant 4, Agent fC and (Patent attorney Nori Takano of 721 Next 58 Date of amendment order Voluntary 6 Number of inventions increased by amendment 7, Claims of the specification subject to amendment, and detailed description of the invention column. 88 Contents of amendment Attachment (1) Amend the claims as shown in the attached sheet. (2) Add l -PbZr0. ) "0,08 j" in the 4th line of the specification, line 11
Correct to 0.80''. (4) Sample number 2-42 in Table 26 of No. 38 of the specification
Change [3700J to [3940J, Kp
All "61.9" in the column are corrected to "62.5J. (5) Column εr in the row of sample number 2-46 in Table 26 of Specification No. 38 (7) l'-3430Ji [3630Jf
Correct [61,5J in the columns c and Kp to [63,3J, respectively. (6) Correct “0.00” in the principal component column of the row of sample number 3-9 of the 42nd negative table 27 of the specification to l” 0,10j. (7) The 42nd negative table of the specification Sample number 3-10 (1
) Correct [0,OOJ in the principal component column of the row to "0.IO". (8) [(1,1La)TiO,, (LiBi)Tie, J
f"(,LiLa)+nameTiO,,(LiBi)z
i, "io, J K corrected. (9) Sample number 4-64 in Table 39 of Specification No. 59
Correct "F-9" in the row by [2-L5JK. 00) Sample number 4-73 in Table 40 of Member 60 of the Specification
"Correct F-9J by l'-2-15JK. Ql) Sample number 4-81 in Table 41, page 61 of the specification
The line l'-I-13'' is corrected to [2-42j. (12+ Sample number 4-8 in Table 42 of Member 62 of the specification)
"Correct l-13J to l-2-42J in line 9. u31 Sample number 4-98 in Table 43 of member 63 of the specification
Correct "J-11J" in the row to "l"'2-46J. 0 Excellent In the row of sample number 4-106 in Table 44 of member 64 of the specification, "J-11J is corrected by l'-2-46, JK. 2. Claims fil X-(a-Pb(Zn+ , (NbH)0.-
b・PbTi0. -c・PbZr0. )-Y・(LIL
a)+, (Ti(4-Z・(LiHi)+, (TiO). (However, the values of the above X, Y%Z, a, b, c are
0.80≦X≦0.96.0.02≦Y as 10Z-1
≦0.10.0.02≦Z≦0.10, a ten b ten e
+ = l as 0.10≦a≦0.50.0.10≦
b≦0.65.0. niobium oxide (Nb, 0°) or antimony oxide (sb, o,) or a mixed component thereof is present in an amount of 0.3% to 3.0% by weight. A piezoelectric porcelain composition characterized in that it is not added in a range of 0% by weight. (21X・(aHPb(Znt,(Nb6)0.-b・
l'bTiO, -c・l'bZrO, ]-Y-(LiL
a) +, (Ti03-'1-(LiHi)+, (TiO
. (However, the values of X, Y, Z, a, b, c are X+Y
+Z=1, 0.80≦X≦0.96.0.02≦Y
≦0.10.0.02≦Z≦0.10, 8 10b 0.10≦a≦0.50.0.10≦b with 10C=1
0.65, 0.10≦C≦0.80), niobium oxide (NbmOs), antimony oxide (Sbmis), or a mixed component thereof is 0.3% to 3% by weight. 0% by weight, 0% oxidation (Cr, 0%)
A piezoelectric ceramic composition characterized in that 0.1 to 5.0% by weight of @ ) and 0.1 to 2.0% by weight of aluminum oxide (A1°0, ) are added.

Claims (1)

[Claims] 11I X-[a-Pb(Zn2Nb, B6)0. −
b・PbTi0. -c・PbZr0. ]-Y ・(Li
La)y, 1゛i0. -Z-(LiBi)2'
riO. (However, the values of X, Y, Z, a, b, c are as follows.x+y+z=]0.08≦X≦0.96.0.0
2≦Y≦Q40, 0.02≦Z≦0.10. a+
1) +c=1, 0.10≦a≦0.50, 0.1
0≦b≦650, JO≦C≦80] Niobium oxide (Nb, 0.) or antimony oxide (Sb) or a mixed component thereof is added at vO03X% A porcelain composition containing 1% to 3.0% by weight of additives. [21X・[a-Pb(ZngNbz)Us-b-Pb
'l'i0. -c-PbZrO,)Y l(Lt 1.
a) I'I'l0II-Z, (LtBt)
, A'l't03 (Tatashi, the above X, Y, Z, a, b,
The value of c is. X+Y+2. = 1,! I L Te0.08≦X≦0
．． 96, 0.02≦Y≦0.10, (1,(
12≦Z≦040. 0.10≦a as a+h+c=1
≦l), 50, 0.10≦b≦0.65゜0.10≦
C≦0.80), niobium oxide (Nb, o, ) or antimony oxide (Sbmoa) or a mixture thereof is 0.3net% to 3.0net%. Omjli chromium oxide (,
: r tO, ) is 0.1 to 5.0% and aluminum oxide (AI, O,) is added 0.1 to 2.0%. Composition.