JPS5968107A - Pyroelectric porcelain material - 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 provides a stable l~
The present invention relates to an excellent pyroelectric porcelain material with such characteristics.

It is a method for measuring the surface temperature of objects near room temperature or the skin temperature of the human body without directly touching them.
A widely used method is to use a pyroelectric infrared detection element to detect the intensity of infrared rays emitted from an object to be detected depending on its temperature.

The pyroelectric detection element absorbs infrared rays emitted from the object to be detected, and uses changes in spontaneous polarization caused by temperature changes in the pyroelectric element as a signal. surface temperature can be detected easily and accurately. In addition, the infrared intensity corresponding to the temperature near normal temperature has a wavelength of i.

It has a maximum value in the vicinity of microns, and a method is usually used in which the maximum value is detected by an element.

The pyroelectric material used in such a pyroelectric infrared detection element has a larger change in spontaneous polarization with respect to temperature change, that is, a pyroelectric coefficient (clPs/dT), and a relative dielectric constant (E
6) is better as it is smaller, and it is industrially desirable to be able to manufacture it easily and provide it at low cost.

In addition, as pyroelectric materials, conventional single crystals such as glycine sulfate, lithium niobate (Li, NbO5) + lithium tantalate (LiTaO3), and lead ticunate (
PbTiC1,), lead zirconate titanate (PbZr
Magnetic materials such as Tio3) are known.

However, glinone sulfate crystals are water-soluble and brittle, and it is difficult to add T to them, making it difficult to manufacture pyroelectric materials.Furthermore, the temperature at which pyroelectricity disappears, that is, the Curie temperature, is 52°C. This extremely low temperature severely limits its operating temperature range.

1. Lithium niobate crystal has good workability, but its pyroelectric coefficient (dPs/dT) is small and it is expensive, so it is not practical.] 2. Lithium tantalate has good workability and pyroelectric performance. It is a preferable material because it has a relatively large index, but it is industrially disadvantageous because it is expensive. Furthermore, titanic acid (has a large daPs/dT and a relatively small dielectric constant, but is difficult to sinter, and the lead component evaporates during firing.
Lead zirconate titanate has the disadvantage that it is difficult to obtain a porcelain material with a stable uniform composition and pyroelectric properties, and lead zirconate titanate has good processability (d, Ps/dT are also large, It has the disadvantage that it is thick.

The present inventors have found that the processability is particularly good (excellent clPs/dT).
As a result of repeated research on lead zirconate titanate material C, in order to improve its drawback Ks and develop lead zirconate titanate-based pyroelectric porcelain 41'-), which has excellent pyroelectric performance. An extremely desirable pyroelectric material 4'-1 has been discovered.

That is, the present invention provides zirconate titanate having a composition represented by the formula %, where X is 0.005 to 0.06, and y is within the range of 0.10 to 0.40. Pyroelectric magnetism+All, which is characterized by containing a lead-based compound as a main component, and further containing diacid ratio mancannu t, chromium oxide, or both in a range of 0.1 to 1.5 weight ratio of the compound. It provides:

In the lead zirconate titanate compound represented by the above formula used for the monthly profit of the present invention, X is within the range of 0.005 to 0.06, and y is 0. It is necessary to be within the range of lO ~ 0.40, and if it deviates from this combination range, the pyroelectric coefficient (dos/dT) becomes small or the relative dielectric constant (gs)
This is not preferable because the properties of the pyroelectric material are reduced. The desirable range for each is 0.01~
0.04, 7 is 0.15 to 0.3.

In addition, MnO2 and Orr used in the material of the present invention
It is important that 203 is blended in a weight ratio of 0.1 to 1.5 with respect to the compound represented by the above formula either as one of the components or as a mixture. If l- is outside this range ((
is associated with the combination of values of X and y in the above formula, and M
nO2 and C! Differences with r03 ((yoshi, d, Ps/d
T or E! Either or both of I would be extremely undesirable, and the object of the present invention would not be achieved.

The lead zirconate titanate compound represented by the above formula r can be easily prepared, for example, as follows.

Chemically pure PbO, NbO5, ZrO2 and Tl
Using O2, determine the desired value of X and y in the above formula within the range of 0 and weigh each metal oxide powder so that the value becomes the value, and then add MnO2 powder or 0r203.
Weigh the powder or both at a weight of 1 to 1.5 times the total weight of each of the metal oxide powders, mix it with all the metal oxides, and then crush it, preferably using a ball mill. The mixture is thoroughly pulverized using a mixer to form a mixture as homogeneous as possible, and then pre-calcined at a temperature of, for example, 800° C. for 2 hours. Next, this calcined product is again pulverized and mixed using a pulverizer such as a ball mill, and a commonly known organic binder such as polyvinyl alcohol is added and kneaded, and after being pressure-molded into a desired molded product, it is further pulverized at a higher temperature. For example 120
Main firing is performed at a high temperature of 0° C. or higher, for example, for about 2 hours.

The magnetic material fired in this way is made of a compound having a predetermined y value represented by the above formula and a y value as a main component. A magnetic material with excellent pyroelectric properties is provided by applying a direct current high voltage of 3 KV/gas in oil at a temperature of 0.degree. C. for polarization.

The pyroelectric magnetic particle of the present invention, which is easily prepared in this way, is extremely dense, has a large dPs/dT, and a small E
s, is easy to manufacture and process, is inexpensive, stable, and has a wide detection temperature range, and is extremely desirable as a pyroelectric detection element from an industrial and practical standpoint.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Examples 1 to 9 PbO, Nb2O5, ZrO2 and TiO2 in powder form are each weighed out in proportions that form a compound in which X and y in the above formula have predetermined values, and each of these metal oxides is weighed to form a compound with a total of 4 weights. It was placed in a ball mill together with MnO2 powder equivalent to 0.5 weight percent and sufficiently ground and mixed.

After calcining this fine powder mixture at a temperature of 800° C. for about 2 hours, it was sufficiently ground and mixed again in a ball mill, and an organic binder was added thereto and kneaded. The resulting mixed material was heated to a diameter of 20 mm and a thickness of 1 m at a pressure of approximately 2 tons/crl.
It was press-molded into a disk of 1.5 m in diameter and heated at 1200° C. for 2 hours to perform main firing.

Next, the electrodes were brought into contact with both sides of the fired disk at approximately 100°C.
Immerse it in oil at a temperature of , and apply 3't to both electrodes! ;N/mm
A pyroelectric porcelain material was prepared by applying a DC voltage of

In this way, when X is 0 and y is 0 with a constant value of I33,
．． 10.0.15.0.20.Various compounds of 0.30 or 0.40 and y is a constant value of 0.15 and X is 0.0
Disc-shaped pyroelectric magnetic materials containing itMn02 (0.5-layer) of various 1-hybrid compounds of 05゜0.02, 0.04 or 06 were prepared, and the pyroelectricity of each material was Coefficient (dos
/dT) and relative permittivity were measured.

Table 1 shows the X and y values of the compounds in each of these materials and the measurement results of each pyroelectric property.

Table 1 Examples 1O to 18 In the same manner as in the previous example, disc-shaped specimens were prepared from compositions in which X was 0.03 and y was 0.15, and the amount of MnO2 or Cr2O3 added or the combined amount of both components was varied. The pyroelectric properties of the pyroelectric porcelain materials were investigated.

Table 2 shows the types of additive components, the amounts added to the total weight of the metal oxides constituting the compound composition (weight ratio), and the measurement results of their properties.

Table 2 shows the pyroelectric properties and industrial evaluation of conventional pyroelectric materials in contrast to the porcelain material of the present invention, which is dense, stable, and inexpensive, and has excellent workability such as sinterability and pyroelectric properties as described above. For comparison, No.: (shown in the table).

From the above Table 3, it can be seen that the porcelain powder of the present invention has superior practicality compared to conventional ones.

Patent γI applicant Tokyo Denki Kagaku Kogyo Co., Ltd. Agent A
Form Clear procedural amendment 昭+u 58 q May 27ゝli′1中・I′l
Nono, 1981 Patent Application No. 178896 2 Invention and I (4 Relation with Pyroelectric Porcelain Material 31 Yama 1 (4r 1i1'l) Patent Applicant fI Place Chuo Ward Nihonbashi-chome 13-1 Representative Nagisa Otoshi Hiroshi 4 Representative 5 Lot+l:ffh <t]l:IN Spontaneous patent claim is represented by formula 1, where X in the formula is 0.005 to 006 A lead zirconate titanate compound having a composition in which y is in the range of o, io-0,40?The main component is manganese dioxide or chromium oxide in an amount of 01 to 1.5% by weight of the compound.
A pyroelectric porcelain material characterized by containing within the range of.

Claims (1)

[Scope of Claims] A titanic acid having a composition represented by the following formula (%), in which X is 0.005 to 0.06 and y is 0.10 to 0.40. A pyroelectric porcelain material comprising a lead zirconate compound as a main component and further containing manganese dioxide or chromium oxide in an amount of 0.1-1.5% by weight of the compound.