JP2007084357A - Reaction preventing member to lead-containing compound - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reaction preventing member to a lead-containing compound in which the reactivity with the lead compound such as PZT (Lead zirconate titanate) is more reduced and a sintered compact small in the variation of piezoelectric characteristics is obtained even in the firing of a piezoelectric body. <P>SOLUTION: The reaction preventing member contains zirconia as an essential ingredient, calcia and yttria as second ingredients and at least one kind of an oxide of group IIA elements except Ca and group IIIA elements except Y as third ingredients and comprises cubic zirconia as a main crystal phase and does not substantially comprise a grain boundary crystal phase except zirconia and the ratio Xc of the cubic crystal in the zirconia sintered compact expressed by formula (1) and formula (2) is ≥0.97. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an application to a firing jig mainly used for heat treatment such as firing of electronic material parts. For example, a ceramic capacitor, a ceramic filter, a ceramic resonator, an injector actuator for fuel injection, an actuator for an inkjet printer head The present invention can be applied to a firing jig suitably used for heat treatment such as firing of a piezoelectric element such as a piezoelectric resonator, an oscillator, an ultrasonic motor, an acceleration sensor, a knocking sensor, or an AE sensor.

  Conventionally, products using a piezoelectric ceramic include, for example, an actuator, a filter, a piezoelectric resonator (including an oscillator), an ultrasonic vibrator, an ultrasonic motor, a piezoelectric sensor, and the like.

Among these, actuators have a very high response speed to electrical signals of the order of 10 ⁻⁶ seconds, so they are applied to XY stage positioning actuators for semiconductor manufacturing equipment, ink ejection actuators for inkjet printers, and the like. Yes.

  Piezoelectric ceramics used in such actuators use lead-containing compounds such as lead-containing ceramics such as lead zirconate titanate (hereinafter sometimes simply referred to as PZT). In such a lead compound, since the volatility of lead is high, there is a problem that the composition evaporates from the molded body during firing, causing a composition variation of the sintered body and the composition becomes non-uniform. In particular, the composition variation on the surface was large compared to the inside.

  Therefore, for firing a molded body containing a volatile component such as Pb, a composition (hereinafter referred to as a co-material) containing the volatile component contained in the molded body, which is the same as or similar to the molded body, is used together with the molded body. It has been proposed to suppress the evaporation of volatile components from the molded body, prevent composition fluctuations of the molded body, particularly composition fluctuations and structural changes near the surface, and make the characteristics uniform ( For example, Patent Document 1).

  That is, a compact is placed on a porous setter and loaded into a container, and a co-material is placed around the compact and fired. Therefore, the firing jig used in Patent Document 1 includes a container and a porous setter placed in the container in order to place the molded body.

  However, when firing a laminate of ceramic green sheets with a thickness of several hundreds of μm or less, the composition of the surface has changed compared to the interior, so even if an attempt is made to remove the altered phase on the surface, the thickness is too thin. There was a problem that processing was difficult.

  In addition, since the shrinkage rate varies depending on the site due to composition variation during sintering, deformation such as waviness and warpage occurs, or unevenness is locally generated, making it difficult to obtain a smooth piezoelectric ceramic. there were.

  Furthermore, there is a problem that the piezoelectric characteristics vary depending on the site due to composition variation, and when used in a print head of an ink jet printer, there is a problem that ink discharge variation becomes large and the image quality deteriorates.

For this reason, a material having low reactivity with the piezoelectric ceramic itself has been used. For example, it has been disclosed that zirconia (ZrO ₂ ) has low reactivity as a rug during firing with PZT (see, for example, Non-Patent Document 1).
Japanese Patent Laid-Open No. 10-29872 FIG. Academic publication “Ceramic Dielectric Engineering” P154

However, even if ZrO ₂ is simply used as a firing jig when firing the PZT molded body, there is a problem that PZT and ZrO ₂ react with each other slightly to cause composition fluctuation of the firing jig. When such a composition variation occurs, the surface composition of the firing jig becomes non-uniform, and the characteristics of the PZT sintered body to be fired vary. For example, when PZT is fired as a piezoelectric ceramic, the piezoelectric characteristics of the obtained sintered body vary. Therefore, when a plurality of piezoelectric displacement elements are formed on one piezoelectric ceramic, the piezoelectric characteristics differ among the piezoelectric displacement elements. It was.

  In addition, when the molded body containing lead is repeatedly fired using the same firing jig, the reaction at the reaction site with lead on the firing jig surface proceeds gradually, and the variation in the surface composition of the firing jig becomes remarkable, and each firing lot There was also a problem that the piezoelectric characteristics fluctuated between.

  Accordingly, an object of the present invention is to provide a reaction preventing member for a lead-containing compound that can further reduce the reactivity with a lead compound such as PZT and obtain a sintered body with small variations in piezoelectric characteristics even when the piezoelectric body is fired. Is to provide.

The reaction-preventing member for the lead-containing compound of the present invention is composed of zirconia as a main component, calcia and yttria as a second component, and a group 2a element in the periodic table excluding Ca and a group 3a element in the periodic table excluding Y A zirconia sintered body containing at least one oxide as a third component, cubic zirconia as a main crystal phase, and substantially free of grain boundary crystal phases other than zirconia. The cubic ratio Xc of the zirconia sintered body represented by 2 is 0.97 or more.

  In particular, the content of the second component is preferably 20 to 43 mol% with respect to the total of the content of the main component and the content of the second component.

Moreover, the composition ratio by the molar ratio of zirconia, yttria, and calcia is within a range surrounded by a line segment connecting points A—B—C—D in the ternary composition diagram of ZrO ₂ —YO _1.5 —CaO. It is preferable that

ZrO ₂ CaO YO _1.5
Point A: 0.65 0.03 0.32
Point B: 0.61 0.07 0.32
C point: 0.72 0.18 0.10
Point D: 0.79 0.11 0.10
The average crystal particle diameter of the zirconia sintered body is preferably 10 to 40 μm.

  In the zirconia crystal contained in the zirconia sintered body, it is preferable that the second component and the third component are in solid solution to near the solid solution limit.

  It is preferable that a mounting surface for mounting the lead-containing compound is provided and used as a firing jig.

  The present invention has been made on the basis of a novel finding that cubic zirconia containing a third stabilizer together with calcia and yttria exhibits extremely low reactivity with respect to lead-containing compounds.

  That is, as a zirconia stabilizer, in addition to the second component consisting of calcia and yttria, at least one element group of the group 2a element of the periodic table excluding Ca and the group 3a element of the periodic table excluding Y By making the cubic component of the zirconia sintered body to be 0.97 or more by including the third component made of the oxide of zirconia, the reactivity with the lead-containing compound can be remarkably reduced by the zirconia itself. can do. Accordingly, it is possible to provide a reaction preventing member for a lead-containing compound capable of further reducing the reactivity with a lead compound such as PZT and obtaining a sintered body having a small piezoelectric characteristic variation even when the piezoelectric body is fired. it can.

  The reaction preventing member for the lead-containing compound of the present invention will be described using a firing jig for firing lead zirconate titanate (hereinafter referred to as PZT) as an example.

  The firing jig in the present invention means a jig used when firing a molded body, and examples include a setter for placing the molded body when firing and a firing bowl for placing the molded body and a setter. it can. In other words, a member that is in direct contact with the molded body, such as a setter, or that reacts or may react with lead vapor evaporated from the molded body, such as a firing bowl, is referred to as a firing jig.

  The present invention includes zirconia as a main component, calcia and yttria as a second component, and further, among the element groups of the periodic table group 2a element excluding Ca and the periodic table group 3a element excluding Y It is important to contain at least one oxide as the third component.

  Here, the group 2a element of the periodic table excluding Ca is Be, Mg, Sr, Ba, and the group 3a element of the periodic table excluding Y is La, Ce, Nd, Sm of Sc and the lanthanoid. , Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu.

  According to the present invention, in the zirconia sintered body stabilized by adding 10 to 20 mol% of CaO, Ca is solid-solved in the zirconia crystal at a high temperature, but a part of Ca is at the grain boundary part at the time of cooling. It precipitated to cause a reaction with lead, and the reaction with lead could not be prevented.

Conversely, if the amount of calcia added is small, calcia dissolves in zirconia, but if the amount of calcia added is less than 10 mol%, cubic zirconia becomes thermally unstable and becomes monoclinic from the cubic during cooling. Since phase transformation to crystal ZrO ₂ occurred and monoclinic ZrO ₂ reacted with lead, it could not function sufficiently as a reaction preventing member.

On the other hand, zirconia using other stabilizers such as yttria (Y ₂ O ₃ ) and magnesia (MgO) also reacts with PZT. In particular, zirconia stabilized with yttria is repeatedly fired. In the meantime, lead penetrates into zirconia, the reactivity with the molded body containing lead changes with the number of firings, and the amount of Pb on the surface of the sintered body varies markedly within the surface, resulting in variations in piezoelectric characteristics. It was happening. In particular, the piezoelectric characteristics fluctuated from one firing lot to another.

  For example, in a zirconia sintered body stabilized with a group 3a element of the periodic table such as Y, lead easily diffuses to the inside through a compound of the group 3a element of the periodic table precipitated at the grain boundary. The reactivity becomes high.

However, as a stabilizer, at least one oxide of the group 2a element of the periodic table excluding CaO, Y ₂ O ₃ and Ca and the group 3a element of the periodic table excluding Y is simultaneously contained. it by it is possible to effectively suppress the Ca precipitation of grain boundaries, and can facilitate the uniform solid solution of Ca with respect to ZrO _2. In addition, the thermal stability of cubic ZrO ₂ can be improved, and the reaction with lead-containing compounds such as PZT can be remarkably suppressed.

  By combining the group 2a element of the periodic table and the group 3a element of the periodic table in this way, the precipitation of the second phase at the grain boundary can be effectively suppressed. That is, no crystal phase other than zirconia that easily reacts with the Pb-containing material is deposited. In particular, by adding calcia and yttria and further combining the third component, it is possible to achieve an effect of preventing the additive element from being precipitated at the grain boundary.

Further, the reaction preventing member for the lead-containing compound of the present invention has the above composition, and is composed of a zirconia sintered body having cubic zirconia as a main crystal phase. The zirconia has a crystal structure of cubic, monoclinic, tetragonal. Can take crystals. Among these, monoclinic crystals are easy to react with PbO and cause PbZrO ₃ to be generated, so it is better not to be included as a reaction preventing member. Tetragonal crystals also have a lot of room for solid solution of the substance in zirconia and cause reaction with Pb, so that the crystal phase is preferably only cubic. By using cubic zirconia as the main crystal, the effect of suppressing the solid solution of additives and impurities in zirconia and suppressing the reaction with Pb can be achieved.

  On the other hand, since the cubic crystal is a high-temperature stable phase, the reactivity with PbO is low, and it is important that the cubic crystal is included in the reaction preventing member for the lead-containing compound, and it is necessary to be included as the main crystal phase. In particular, the zirconia sintered body having the following cubic ratio Xc represented by the diffraction intensity by X-ray diffraction of 0.97 or more can further reduce the reactivity with lead and prevent reaction to lead-containing compounds. It is suitable as a member, and when used as a firing jig, it is possible to obtain a sintered body with small variations in characteristics such as piezoelectric characteristics.

  In particular, the cubic ratio Xc of the zirconia sintered body is preferably 0.98 or more, and more preferably 0.99 or more in order to further reduce the reactivity with lead. Zirconia becomes a high-temperature stable phase in the order of monoclinic, tetragonal and cubic crystals.

The cubic ratio Xc in the present invention can be calculated from the spectrum analysis by X-ray diffraction analysis using the following formulas 1 and 2.

  In addition, it is preferable that there is substantially no monoclinic peak. The fact that the X-ray diffraction intensity here is substantially absent means that the intensity is 0.1 or less when the XRD main peak intensity is 100.

For example, FIG. 1 shows the X-ray diffraction spectrum of the reaction preventing member for the lead-containing compound of the present invention, where the horizontal axis is 2θ and the vertical axis is the X-ray diffraction intensity. According to this figure, X _m = 0 and X _c = 1.0 are obtained. Thus, when the cubic ratio Xc is 0.97 or more, it becomes possible to remarkably suppress the reaction with a lead-containing compound such as PZT, and the reaction preventing member of the present invention was used as a firing jig. In this case, it is possible to reduce the piezoelectric characteristic variation on the surface of the fired sintered body, and it is also possible to reduce the piezoelectric characteristic variation among the firing lots even when it is repeatedly used.

FIG. 2 shows an X-ray diffraction spectrum of the reaction preventing member outside the range of the present invention. According to this figure, X _m = 0.039 and X _c = 0.716 are obtained. Thus, when the cubic crystal ratio Xc is smaller than 0.97, a reaction with an orthorhombic crystal, a grain boundary crystal phase or the like occurs, and a reaction with the formed body occurs at the time of sintering.

1 and 2, the measurement is performed in the range of 2θ of 10 to 80 °. However, in calculating _Xc , the region near the peak of the corresponding surface is set to a narrow step width. It is preferable to perform a precise measurement with a longer sampling time in each step, and calculate using an enlarged peak (not shown) near the peak.

  It is important that the zirconia sintered body does not substantially contain a grain boundary crystal phase other than zirconia at the crystal grain boundary. In the present invention, the zirconia sintered body that does not substantially contain a grain boundary crystal phase other than zirconia in the crystal grain boundary refers to one in which a crystal phase other than zirconia is not detected in the X-ray diffraction spectrum. That is, the zirconia sintered body of the present invention is composed of any one of cubic zirconia crystals, tetragonal zirconia crystals and orthorhombic zirconia crystals.

  It is preferable that there is no precipitation of Ca and Y as the second component at the grain boundary of the main crystal phase made of zirconia. By sufficiently suppressing these precipitations, it becomes easier to further reduce the reaction with lead-containing compounds such as PZT.

  In the present invention, the absence of precipitation of the second component means that when the cubic zirconia main peak intensity is 100, the diffraction peak intensity other than that is 0.1 or less by XRD analysis, and the magnification by FE-SEM This means that no precipitated phase is observed when scanning at 3000 magnifications.

  For example, it is preferable that Al is not substantially contained in the grain boundary of the zirconia main crystal phase. Alumina reacts with Ca precipitated at the grain boundaries to form a compound (hexaluminate) with an Al to Ca ratio of Al / Ca of 6 (hexaluminate), which reacts with lead and leads to an uneven lead content on the zirconia crystal Thus, the amount of lead on the surface of the lead-containing compound in contact with the surface becomes non-uniform.

In the present invention, “substantially not containing Al” means that Al is about 300 ppm or less in terms of alumina (Al ₂ O ₃ ).

  Moreover, it is preferable not to contain Si substantially. The reason is that SiO2 easily reacts with PbO and forms a liquid phase at an extremely low temperature of 1000 ° C. or lower.

In the present invention, “substantially free of Si” means that Si is 200 ppm or less in terms of silica (SiO ₂ ).

  It is preferable that the second component and the third component are dissolved in the zirconia crystal of the zirconia sintered body to almost the solid solution limit. Thereby, while stabilizing a zirconia crystal | crystallization more, crystal phases other than a cubic crystal can be decreased easily, and the reactivity with respect to a lead containing compound can further be improved.

  The solid solution ratio in the zirconia crystal can be confirmed by measurement called lead belt crystal structure analysis. In other words, when the lead belt crystal structure analysis is performed based on the X-ray diffraction data and the numerical value of the lattice constant is calculated, if the amount of solid solution increases and reaches the solid solution limit, the amount of additional elements is increased further. Even so, the lattice constant is constant. Therefore, the value near the solid solution limit can be set to a state slightly smaller than the maximum value of the lattice constant.

  It is preferable that the content of the second component is 20 to 43 mol%, particularly 25 to 40 mol%, based on the total of the content of the main component and the content of the second component. Thereby, cubic zirconia is sufficiently stable and it is easy to suppress the formation of monoclinic zirconia, and it becomes even easier for the additive elements to be dissolved in the zirconia in the entire amount, and the second component becomes the grain boundary. And the reactivity can be more effectively reduced.

  Note that the content of the third component is 0.1 to 1 mol part, particularly 0.15 to 0.8 mol part, and further 0 when the total amount of the main component and the second component is 100 mol parts. .2 to 0.5 mole part is preferred.

Although it is important to use CaO and Y ₂ O ₃ as stabilizers with respect to ZrO ₂ , the composition is determined by the molar ratio of each component of ZrO ₂ —YO _1.5 —CaO. The following points in the ternary composition diagram of ZrO ₂ —YO _1.5 —CaO
ZrO ₂ CaO YO _1.5
Point A: 0.65 0.03 0.32
Point B: 0.61 0.07 0.32
C point: 0.72 0.18 0.10
D point: 0.11 0.11 0.10
It is preferable to set within the range surrounded by the line segment connecting the A-B-C-D points. As a result, the reaction with lead-containing compounds such as PZT can be further reduced, and the surface composition variation of the zirconia sintered body can be further reduced. The characteristic variation can be further reduced. Therefore, it can be used more suitably for heating and heat treatment jigs such as firing jigs.

  The average crystal particle diameter of the zirconia sintered body is preferably 10 to 40 μm, particularly 25 to 38 μm, and more preferably 30 to 35 μm. As a result, even when repeatedly exposed to high temperatures, creep deformation is unlikely to occur, and thinning is facilitated. The average crystal particle size was measured using a scanning electron microscope (SEM).

  The zirconia sintered body as described above can be suitably used as a reaction preventing member for a lead-containing compound. In particular, when heat treatment is performed under conditions such as a Pb atmosphere or a high temperature of 600 ° C. or higher, Therefore, it can be suitably used as a heat treatment jig having a mounting surface for mounting a lead-containing compound. By using such a firing jig, it is possible to easily produce a homogeneously baked PZT porcelain.

  In particular, when a thin molded body containing lead for producing a piezoelectric ceramic and having a thickness of several hundred μm or less is fired, it is molded even if it is placed on the placing surface of the firing jig and subjected to heat treatment. Since there is substantially no reaction between the body and the firing jig, the piezoelectric ceramic obtained by firing can produce a sintered body with very little warping and waviness.

  It goes without saying that the reaction preventing member for the lead-containing compound of the present invention can be suitably used not only for a firing jig but also for a heat treatment jig used for heat treatment at 600 ° C. or higher, particularly 700 ° C. or higher, and further 800 ° C. or higher. For example, in heat treatment such as annealing treatment of lead-containing compounds, reaction treatment such as oxidation and reduction, and bonding treatment, the non-treated material is placed on a setter so as to come into contact with the non-treated material containing the lead-containing compound. In the case where the non-processed material is sandwiched between the pair of flat plate reaction preventing members, the influence of lead which is a volatile element from the non-processed material can be reduced during the heat treatment. Can suppress surface composition fluctuations after heat treatment.

  In particular, a common electrode and a piezoelectric layer are laminated in this order on the diaphragm, a plurality of surface electrodes are formed on the piezoelectric layer, a surface electrode, a common electrode facing the surface electrode, and these electrodes Even if heat treatment is performed on an actuator for a print head of an ink jet printer in which a plurality of piezoelectric displacement elements composed of piezoelectric layers sandwiched between them are formed, variation in displacement between the plurality of piezoelectric elements can be easily controlled. Dispersion variation between heat treatment lots can be suppressed.

  A method for producing a reaction preventing member for the lead-containing compound of the present invention will be described below.

  First, raw material powder is prepared. As the zirconia powder, it is preferable to use zirconia powder made of cubic zirconia. Monoclinic zirconia and tetragonal zirconia partly undergo phase transition to cubic zirconia during sintering, but in order to increase the Xc value of the zirconia sintered body to 0.97 or more, the cubic ratio of the raw zirconia powder Xc is preferably at least 0.95.

  It is preferable to use a zirconia powder having an average particle size of about 0.1 to 1 μm.

As the second component powder, CaO powder may be used directly, or CaO may be formed by heat treatment of Ca hydroxide, carbonate or nitrate. The CaO powder is preferably about 0.3 to 1 μm. _Further, Y 2 _{O 3} powder is preferably used having an average particle size of about 0.1 to 1 [mu] m.

  As the third component powder, a group 2a element of the periodic table excluding Ca, and oxides, hydroxides, nitrates, and the like of the group 2a element of the periodic table can be used. Moreover, the oxide of a 3a group element of a periodic table can be used as a 3a group element of a periodic table except Y.

  The above zirconia powder and additive powder, an organic solvent such as IPA, and zirconia balls are put into a resin pot, mixed and pulverized. The obtained mixed powder is heat-treated to produce a synthetic powder containing the first component, the second component, and the third component. For example, the mixed powder can be heat-treated at 1000 to 1400 ° C.

  The obtained synthetic powder is pulverized using zirconia balls until the average particle size is about 0.3 to 0.8 μm. An organic binder and a solvent are mixed with the pulverized raw material powder to produce a slurry, and the obtained slurry is used to produce a green sheet by a known molding method such as tape molding, casting molding or injection molding. The obtained green sheet is cut into a desired size, and a plurality of green sheets cut as desired are laminated to produce a molded body. The slurry may be dried to produce a dry raw material, and a molded body having a desired shape may be produced from the dry raw material by a method such as press molding.

  The obtained molded body is degreased at a desired temperature, for example, 300 to 500 ° C., and then fired at a desired temperature, for example, 1200 to 1700 ° C., particularly 1300 to 1600 ° C., to obtain a reaction preventing member. it can.

  A reaction preventing member for a lead-containing compound was prepared.

ZrO ₂ having a cubic crystallization ratio of 0.95 or more as a starting material and the additives shown in Table 1 were charged into a resin pot together with IPA and φ2 mm zirconia balls, and mixed and pulverized for 16 hours. Thereafter, the powder was put in an alumina crucible having a purity of 99.9% and heat treated at 1200 ° C. for 2 hours to produce a synthetic powder. The synthetic powder was pulverized with φ2 mm zirconia balls for 20 hours, mixed with 5 wt% of paraffin wax in the obtained powder, and granulated through a # 40 nylon mesh. After granulation, it was press-molded into 30 mm × 20 mm × 2 mm. The molded body was subjected to binder removal at 400 ° C. × 2 Hr, and then fired in air at 1550 ° C. × 2 Hr to obtain a reaction preventing member made of a zirconia sintered body.

The reaction preventing member for the obtained lead-containing compound was subjected to composition analysis by fluorescent X-ray analysis. For quantitative analysis, a calibration curve using a periodic table group 2a element oxide other than ZrO, CaO, Y ₂ O ₃ and Ca and a periodic table group 3a element oxide other than Y was prepared in advance. The calibration curve was used.

  The crystal grain size of the zirconia sintered body was measured using a scanning electron microscope (SEM).

  Moreover, about the reaction prevention member used by the following reaction test, surface processing was performed so that surface roughness Ra might be set to 0.01-0.05.

  Next, the reaction preventing member for the prepared lead-containing compound was evaluated.

  A piezoelectric ceramic powder containing lead zirconate titanate having a purity of 99% or more was prepared as a raw material for the lead-containing compound.

  The green sheet is made by adding butyl methacrylate as an aqueous binder, polycarboxylate ammonium salt as a dispersant, isopropyl alcohol and pure water as a solvent to a piezoelectric ceramic powder mainly composed of lead zirconate titanate. After mixing, this slurry was produced in a sheet shape having a thickness of about 30 μm on a carrier film by a doctor blade method.

  Similarly, green sheets were prepared using various piezoelectric ceramic powders. Also, an internal electrode paste was prepared. The obtained internal electrode paste was printed on the surface of the green sheet with a thickness of 4 μm to form an internal electrode. Further, one green sheet on which the internal electrode paste was not printed was laminated between two sheets of green sheets with the surface on which the internal electrodes were printed facing upward, and pressed to obtain a laminated molded body.

  In this manner, laminated molded bodies having thicknesses of 45 μm (No. 1 to 10 and 14 to 27), 80 μm (No. 12), 125 μm (No. 13), and 300 μm (No. 11) were produced. After degreasing the laminated molded body, the laminated molded body was placed in a firing furnace so as to be sandwiched between reaction preventing members having the compositions shown in Table 1. This was held for 2 hours in an atmosphere of 900 ° C. and oxygen 99% or more and fired to produce a laminate composed of a piezoelectric vibration layer and internal electrodes.

  This was held for 2 hours in an atmosphere of the temperature shown in Table 1 and oxygen of 99% or more and fired to produce a laminate composed of a piezoelectric vibration layer and internal electrodes.

  The X-ray diffraction spectrum of the setter surface used for firing was evaluated, and Xc was calculated using the above formulas 1 and 2.

  Moreover, the presence or absence of a grain boundary precipitation phase was also confirmed by X-ray diffraction spectrum and FE-SEM.

Next, the presence or absence of a reaction layer was confirmed after firing 1, 5, 10, 50, 100, and 500 times. In addition, the presence or absence of the reaction layer is detected by conducting surface analysis with a scanning electron microscope (SEM) and EDS on the surface of the reaction preventing member in contact with the lead-containing compound. When it was, it was displayed as ○. The results are shown in Table 1.

  Sample No. of the present invention. In Nos. 1 to 17, the reaction phase could not be observed even when firing at least 50 times, and the reaction with the laminated molded body was suppressed.

  On the other hand, the sample Nos. Out of the scope of the present invention in which the cubic ratio Xc is less than 0.95 and 0.97. In No. 18, no reaction phase was observed in the first firing, but in the fifth firing. In addition, the sample Nos. 3 and 9 out of the scope of the present invention where the cubic ratio Xc is 0.92 or less and less than 0.97. In 19-21, a reaction phase was partially observed on the setter surface in the first firing. Furthermore, the sample No. outside the scope of the present invention in which the grain boundary crystal phase was detected. In Nos. 22 to 27, a reaction phase was observed on a part of the setter surface in the first firing.

It is a ternary composition diagram of ZrO ₂ —YO _1.5 —CaO showing the composition range of the reaction preventing member of the present invention. It is a figure which shows the X-ray-diffraction spectrum of the reaction prevention member of this invention. It is a figure which shows the X-ray-diffraction spectrum of the reaction prevention member outside the range of this invention.

Claims (6)

Zirconia as the main component, calcia and yttria as the second component, and at least one oxide from the group 3a element of the periodic table excluding Ca and the group 3a element of the periodic table excluding Y as the third component A cubic crystal of a zirconia sintered body represented by the following formulas 1 and 2, comprising cubic zirconia as a main crystal phase and substantially free of grain boundary crystal phases other than zirconia. A reaction preventing member for a lead-containing compound, wherein the ratio Xc is 0.97 or more.

2. The lead-containing compound according to claim 1, wherein the content of the second component is 20 to 43 mol% with respect to the total of the content of the main component and the content of the second component. Reaction prevention member. The composition ratio by the molar ratio of zirconia, yttria and calcia is within the range surrounded by the line segment connecting the points A-B-C-D of the following points in the ternary composition diagram of ZrO ₂ —YO _1.5 —CaO. The reaction preventing member for a lead-containing compound according to claim 1 or 2.
ZrO ₂ CaO YO _1.5
Point A: 0.65 0.03 0.32
Point B: 0.61 0.07 0.32
C point: 0.72 0.18 0.10
Point D: 0.79 0.11 0.10 The average crystal particle diameter of the said zirconia sintered compact is 10-40 micrometers, The reaction prevention member with respect to the lead containing compound in any one of Claims 1-3 characterized by the above-mentioned. The lead according to any one of claims 1 to 4, wherein in the zirconia crystal contained in the zirconia sintered body, the second component and the third component are dissolved in the vicinity of a solid solution limit. Reaction preventing member for contained compounds. The reaction preventing member for a lead-containing compound according to any one of claims 1 to 5, further comprising a mounting surface for mounting the lead-containing compound and used as a firing jig.

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