US20090241554A1

US20090241554A1 - Peltier device and temperature regulating container equipped with the peltier device

Info

Publication number: US20090241554A1
Application number: US12/295,598
Authority: US
Inventors: Tetsuaki Nishida; Kenichi Kobayashi; Akira Morishige; Kazumi Manabe
Original assignee: Kitakyushu Foundation for Advancement of Industry Science and Technology
Current assignee: Kitakyushu Foundation for Advancement of Industry Science and Technology
Priority date: 2006-03-31
Filing date: 2007-03-30
Publication date: 2009-10-01
Also published as: JP5024835B2; JPWO2007114317A1; WO2007114317A1

Abstract

An object of the present invention is to provide a Peltier device capable of retaining a certain temperature at a high accuracy by using a conductive glass consisting primarily of vanadate as an electrode, excellent in handleability, easy in temperature regulation, excellent in stability of cooling performance, capable of securely preventing an electrode from corrosion resulting from chemicals or dew condensation etc., and excellent in reliability and durability of the electrode.

The Peltier device has a heat absorbing portion and a heat emitting portion, in which at least the electrode of the heat absorbing portion is formed with the conductive glass consisting primarily of vanadate.

Description

TECHNICAL FIELD

The present invention relates to a Peltier device easy in regulating temperatures and excellent in handleability and also relates to a temperature regulating container equipped with the Peltier device capable of optimally regulating the temperature of a specimen in making observations of tissues and cells in the body or the operation thereof etc., in the research field etc., of biotechnology or making microscopic observations and the operation thereof, with the temperature of a specimen regulated, when quality control or material tests etc., are conducted in medical and industrial fields.

BACKGROUND OF THE INVENTION

Conventionally, in a temperature regulating system for cultivation used in biotechnology and medical fields, a method is used in which a medium such as an antifreeze liquid or water is changed in temperature to circulate it around a specimen by using a pump and a method in which the polarity of a cooling module is shifted to attain a change in temperature or temperature regulation. In the method in which a medium is changed in temperature to circulate it by using a pump, there are problems that a circulating channel of the medium must be retained heat to result in larger dimensions of the system, thereby a difference in temperature easily takes place during circulation, and the system is insufficient in response to heating or cooling, thereby making it difficult to regulate temperatures at a high accuracy.
In the method in which the polarity of a cooling module is shifted to attain a change in temperature or temperature regulation, there are problems that the cooling module is greatly damaged and lacks a longer operation life and reliability as the system.
Both of the above methods are able to heat and cool a plurality of incubators or the like at the same time but have problems that they are unable to individually heat and cool containers having a very small accommodation space or selectively heat and cool an incubator provided with a plurality of cells on a single cell basis and therefore lack versatility.
Further, (Patent Document 1) has disclosed a method for selecting cultured cells by using a temperature responsive high-molecular compound in which cells cultured in an incubator where the temperature responsive high-molecular compound is used as a cell culture base material are observed microscopically at temperatures higher than a critical point at which the temperature responsive high-molecular compound starts to deposit from water, a cooling fluid is sprayed to effect cooling, without blocking light paths of transmitted light, until the temperature responsive high-molecular compound within range of vision is cooled down to a temperature lower than the critical point, thereby only desired cells or cell masses are selected and removed from the container for collection.
(Patent Document 2) has disclosed “a heating/cooling dual-purpose system which is constituted in combination of a temperature-elevating glass plate functioning as a heater in which a positive electrode and a negative electrode are attached so as to face each other around transparent glass on which a transparent conducting film is formed by vacuum deposition and one or a plurality of cooling modules utilizing the Peltier effect.”
[Patent Document 1] Japanese Published Unexamined Patent Application No. 2003-102466
[Patent Document 2] Japanese Published Unexamined Patent Application No. H9-122507

DISCLOSURE OF THE INVENTION

Objects to be Solved by the Invention

However, the above-described conventional technologies have the following problems.
(1) In the method for selecting cultured cells as disclosed in (Patent Document 1), a heating plane for placing an incubator to heat the bottom thereof, a hole opened at the center of the heating plane for transmitting light in a small area and an ejection port for spraying a cooling fluid to the bottom of the incubator facing the hole are provided thereby making it possible to cool only a small area. With an aim of selecting and collecting only desired cells from several types of cells, this method has a problem that it is unable to heat or cool a very small space at any given temperature, used only in selecting cultured cells and therefore lacking in versatility.
(2) There is a problem that since the main body is formed with hard glass, the heating/cooling dual-purpose system as disclosed in (Patent Document 2) is difficult to subject to fine processing, lacking in configuration flexibility, unable to form a very small space for accommodating a chemical solution or an aqueous solution etc., thereby lacking in handleability and versatility.
The present invention has been made for solving the above problems, an object of which is to provide a Peltier device capable of retaining a certain temperature at a high accuracy by using a conductive glass consisting primarily of vanadate as an electrode, easy in temperature regulation and excellent in handleability and also a temperature regulating container equipped with the Peltier device which is easy in processing the container main body, excellent in configuration flexibility, capable of forming a very small space to accommodate a chemical solution or an aqueous solution etc., excellent in chemical resistance and preservability, capable of effectively heating or cooling a very small space at which the chemical solution or the aqueous solution etc., is accommodated and retaining it at any given temperature stably, thereby making observations and various measurements effectively in a short time and excellent in reliability, versatility and workability.

Means for Solving the Objects

In order to solve the above problems, the Peltier device of the present invention and the temperature regulating container equipped with the Peltier device are constituted as follows.
The Peltier device of the first aspect of the present invention is a Peltier device having a heat absorbing portion and a heat emitting portion, in which at least an electrode of the heat absorbing portion is constituted so as to be formed with a conductive glass consisting primarily of vanadate.
According to the above constitution, the following actions are obtained.
(1) Since the electrode of the heat absorbing portion is formed with a conductive glass consisting primarily of vanadate, it is possible to cool a target substance by changing temperatures slowly. Therefore, the target substance is easy in temperature regulation, able to retain temperatures at a high accuracy approximately to a constant level and excellent in stability of cooling temperatures.
(2) Since the electrode is formed with a conductive glass consisting primarily of vanadate, it is possible to securely prevent the electrode from corrosion resulting from chemicals or dew condensation etc., thereby making the electrode excellent in reliability and durability.
In this instance, the conductive glass (vanadate glass) consisting primarily of vanadate includes a vitrified substance by adding alkali metal oxides such as diphosphate pentaoxide, potassium oxide and sodium oxide, alkaline earth oxides such as barium oxide, or cerium oxide, tin oxide, lead oxide and copper oxide etc., to vanadium oxide.
This conductive glass is produced by a vitrification step in which a vanadium-containing composition is vitrified to produce an oxide glass and by a reheating step in which the oxide glass is retained for a predetermined time at an annealing processing temperature, or a temperature range higher than a glass transition temperature of the oxide glass but lower than a melting point, and preferably at a temperature higher than the crystallization temperature of the oxide glass but lower than the melting point.
A crystallization temperature and a melting point may be determined through actual measurement of the oxide glass by using differential thermal analysis (DTA) or differential scanning calorimeter (DSC) etc. Further, it may also be determined by thermodynamic calculation or the like using a constitutional diagram of constituents to be estimated.
Where a crystallization temperature is determined by the differential thermal analysis (DTA), a center point of heat generation peak of crystallization or a temperature determined on the high temperature side at the foot of the peak is given as the crystallization temperature. Further, where a melting point is determined by the differential thermal analysis (DTA), a temperature at the center point of endothermic peak at a temperature higher than the crystallization temperature is given as the melting point.
There is no particular restriction on means for vitrifying a composition in the vitrification step, as long as a composition such as a mixture of crystalline solids may be changed to a liquid or a gas and then converted to an oxide glass which is a solid lower in temperature than the glass transition temperature without crystallization. For example, a composition such as a mixture of crystalline solids is heated, dissolved and rapidly cooled, thereby making it possible to obtain an oxide glass. Further, the oxide glass may be obtained by converting a composition such as a mixture of crystalline solids once into a vapor state using an evaporation method, sputtering, glow discharge or the like. Still further, the oxide glass may also be obtained through conversion to a gel state using the sol-gel method etc.
Means for retaining an oxide glass in the reheating step thereof at a temperature range higher than the glass transition temperature or the crystallization temperature but lower than the melting point is that in which, for example, an electrical furnace or the like is in advance set to be a reheating temperature and the oxide glass is put into the furnace when a temperature inside the furnace is kept constant, the oxide glass is immediately taken out from the electrical furnace or the like after elapse of a target time and cooled by using a fluid such as air, water or iced water, cooled copper plate or stainless steel plate, or a roller made with copper or stainless steel etc. Alternatively, used is a means in which after the oxide glass is reheated for a predetermined time inside a furnace such as an electrical furnace, a temperature inside the furnace is gradually lowered or the oxide glass is placed away from a heat source inside the furnace by inches, thereby allowing the oxide glass to stand to cool inside the furnace. In order to effect reheating, an inert gas atmosphere etc., such as air, nitrogen, argon or the like is realized inside the furnace.
Retention time in the reheating step may be set to be optimum, whenever necessary, so that an oxide glass after the reheating step is increased in electric conductivity. The retention time varies depending on a constitution of the oxide glass, heat capacity and reheating temperature and is set to be 1 to 180 minutes, for example. Where the retention time is shorter than one minute, the electric conductivity is increased to a slight extent due to a small thermal energy given to the oxide glass, and there is found a variance in increase. Where it is longer than 180 minutes, crystallization or fusing is found to result in a decrease in electric conductivity, thereby reducing the productivity. Neither of these cases is preferable.
Where an oxide glass is heated at a temperature lower than the crystallization temperature of the oxide glass in the reheating step, the electric conductivity is increased to a slight extent due to a small thermal energy given to the oxide glass, and such a tendency is found that the increase in electric conductivity easily varies. Further, where the oxide glass is heated at a temperature lower than the glass transition temperature of the oxide glass in the reheating step, it is impossible to remove the distortion of glass skeleton or to reduce the electron hopping activation energy (band gap). As a result, it is difficult to increase the electric conductivity. Where the oxide glass is heated at a temperature higher than the melting point of the oxide glass, the oxide glass is accelerated for fusing and crystallization to result in a decrease in electric conductivity. Therefore, neither of the cases is preferable.
The electric conductivity of oxide glass (conductive glass) at a room temperature of 25° C. may be determined, for example, by a direct current two electrodes method or by a direct current four electrodes method in which silver paste is applied to a specimen made with a glass piece, the thickness of which is 1 mm or lower, dried and silver-containing solder is then used to form electrodes.
The electric conductivity of oxide glass (conductive glass) at 25° C. before the reheating step is in a range from 10⁻⁸to 10⁻⁴S·cm⁻¹, preferably from 10⁻⁶to 10⁻⁴S·cm⁻¹. There is found a tendency that as the electric conductivity becomes lower than 10⁻⁶S·cm⁻¹, it is more difficult to increase the electric conductivity to a practical level even after the reheating step. Where the electric conductivity is lower than 10⁻⁸S·cm⁻¹, this tendency is made more conspicuous, which is, therefore, not preferable. Where the electric conductivity of oxide glass before the reheating step is made higher than 10⁻⁴S·cm⁻¹, restrictions are imposed on the constitution of glass oxides or a temperature history of vitrification step or the like to result in a lower productivity and unstable production, which is not preferable either.
The electric conductivity of oxide glass (conductive glass) after the reheating step may be improved at a room temperature of 25° C. to a range of 10⁻⁴to 1 S·cm⁻¹, preferably from 10⁻³to 1 S·cm⁻¹. Where the conductive glass is applied to an electrode of a Peltier device, there is found a tendency that power consumption is increased as the electric conductivity becomes lower than 10⁻³S·cm⁻¹, which is far from energy saving. In particular, where the electric conductivity is lower than 10⁻⁴S·cm⁻¹, this tendency is made more conspicuous, which is not preferable.
In particular, where a conductive glass is that in which an oxide glass prepared by vitrifying a vanadium-containing composition is retained and reheated for a predetermined time at a temperature range higher than the crystallization temperature of the oxide glass but lower than the melting point, electrons inside the oxide glass are distributed to a higher level in terms of energy, thereby it is possible to produce at a room temperature the conductive glass having high electric conductivity of 10⁻¹S·cm⁻¹or more. Further, only when the conductive glass is retained at a predetermined temperature range for a short time such as 30 minutes, it is possible that the electric conductivity is increased drastically. Still further, if there is a variation in retention time at a predetermined temperature range, the electric conductivity is varied to a slight extent, thereby contributing greatly to a stable production.
The heating time and the retention time etc., are changed in the reheating step, by which the conductive glass is designed to the extent of electric conductivity at a room temperature so as to be regulated at a high accuracy in a range of 10⁻⁴S·cm⁻¹or more. The product yield may be, therefore, increased.
It is noted that the conductive glass may be such that to which additives such as AgI, NaI, Ag, Ag₂O, In₂O₃, SnO, SnO₂are added. This is because the electric conductivity may be increased by the effect of the additives. Further, in addition to AgI, NaI, Ag or the like, a reduction preventive agent such as CeO₂may be added. It is, thereby, possible to prevent additives such as AgI, NaI and Ag from being reduced and retain a higher electric conductivity.
Further, among three composition systems of vanadium oxide (V₂O₅), barium oxide (BaO) and iron oxide (Fe₂O₃) in the oxide glass, the vanadium oxide (V₂O₅) is from 40 to 98 mol % and preferably from 60 to 85 mol %. As the vanadium oxide (V₂O₅) is lower than 60 mol %, there is found a tendency that it is difficult to retain the glass skeleton based primarily on vanadium and also difficult to obtain a higher electric conductivity. As it is greater than 85 mol %, there is found a tendency that functions of regulating the electric conductivity and mechanical characteristics etc., by accessory components are decreased due to a relative decrease in the amount including the accessory components. In particular, where it is lower than 40 mol % or it is greater than 98 mol %, these tendencies are made more conspicuous and therefore not preferable.
Among the three composition systems in the oxide glass, the barium oxide (BaO) is preferable from 1 to 40 mol % and preferably from 10 to 30 mol %. As it is lower than 10 mol %, there is found a tendency that it is difficult to attain a homogenous vitrification and as it is greater than 30 mol %, there is found a tendency that the mechanical strength is decreased to make the vitrification difficult. In particular, where it is lower than 1 mol % or it is greater than 40 mol %, these tendencies are made more conspicuous and therefore not preferable.
Among the three composition systems in the oxide glass, the iron oxide (Fe₂O₃) is preferable from 1 to 20 mol % and preferably from 5 to 20 mol %. As it is lower than 5 mol %, there is found a tendency that valence electrons of iron contribute to electron hopping to a smaller extent, thereby making it difficult to improve the electric conductivity. As it is lower than 1 mol %, this tendency is made more conspicuous and therefore not preferable.
In particular, where the vanadium oxide (V₂O₅), the barium oxide (BaO) and the iron oxide (Fe₂O₃) are respectively in a range from 60 to 85 mol %, from 10 to 30 mol % and from 5 to 20 mol % in terms of molar ratio, an oxide glass is reheated, by which the electric conductivity at a room temperature is increased by more than a few digits to give 10⁻¹S·cm⁻¹or more. It is, therefore, possible to impart excellent properties to electrical heating elements, materials of various electrodes and others.
The conductive glass used in an electrode of a Peltier device is preferable from 0.1 to 5 mm in thickness. There is found a tendency that the electrode is decreased in strength and the electric conductivity is also easily decreased as the conductive glass is lower than 0.1 mm in thickness. There is found a tendency that the resistance is increased to make temperature regulation difficult as it is greater than 5 mm in thickness. These tendencies are not preferable.
The temperature regulating container of a second aspect of the present invention is constituted so as to have a container main body and the Peltier device as set forth in the first aspect which is placed on the bottom or the side of the container main body.
According to the above constitution, the following action is obtained in addition to the action of the first aspect.
(1) Since the temperature regulating container is provided with the Peltier device placed on the bottom or the side of the container main body, it is easier in regulating temperatures, excellent in cooling efficiency and reliability, and excellent in handleability and space saving due to the fact that the container main body and the Peltier device may be handled in an integrated manner.
In this instance, the conductive glass acting as an electrode of a heat absorbing portion of the Peltier device is placed so as to be in contact with the bottom or the side of the container main body. The container main body may be formed with a material which will not be corroded by a chemical solution or a solution accommodated inside and provided with thermal conductivity sufficient in cooling the chemical solution or the solution accommodated inside by contacting with the heat absorbing portion of the Peltier device. For example, preferably used are glass such as quartz glass and a hard synthetic resin. The container main body may be formed partially or entirely with the conductive glass. Where a part of the container main body is formed with the conductive glass, the bottom or the side may be partially or entirely formed with the conductive glass to which the above-described quartz glass, the synthetic resin or the like is attached, thereby forming the container main body. Alternatively, the conductive glass may be attached or film-formed on the outer surface of the inner wall portion formed with the above-described quartz glass, the synthetic resin or the like.
Since the conductive glass may be subjected to fine processing by a focused ion beam processing or the like, the container main body may be easily processed according to a partial or an entire configuration thereof and therefore excellent in productivity.
The invention of a third aspect is the temperature regulating container as set forth in the second aspect, in which the container main body is constituted so as to be at least partially formed with the conductive glass.
According to the above constitution, the following actions are obtained in addition to the action of the second aspect.
(1) Since the container main body is at least partially formed with a conductive glass, it is possible to improve the thermal conductivity and chemical resistance. Therefore, the container main body is able to preserve various chemical solutions or solutions and effectively heat or cool them by heating means or a Peltier device and excellent in versatility and reliability.
(2) Since the container main body is formed with a conductive glass, it may be subjected to fine processing by a processing method such as a focused ion beam. The thus processed container main body is excellent in configuration flexibility, easy in miniaturization thereof and excellent in space saving.
In this instance, where the container main body is partially formed with a conductive glass, in particular, the bottom or the side to be heated or cooled by heating means or a Peltier device is at least partially formed with a conductive glass, it is possible to attain an effective heat transfer between the heating means or the Peltier device and a chemical solution or a solution accommodated inside the container main body, heating and cooling efficiency are made excellent.
The heating means may include any heaters capable of heating selectively the container main body, and those with a heat element or the like are preferably used for this purpose. One or more of the heating means or Peltier devices are placed on the bottom or the side of the container main body, thereby making it possible to effect heating or cooling in a simple manner.
The container main body is preferably provided with a temperature sensor such as a thermocouple. The temperature sensor is used to measure the temperature of the container main body or that of a chemical solution or a solution accommodated inside the container main body, and a controller is used to control the driving of heating means or a Peltier device on the basis of the measurement values, thereby making it possible to retain any given temperature at a high accuracy.
It is noted that the conductive glass which forms the container main body is similar to that used in forming an electrode of the Peltier device.
The invention of a forth aspect is the temperature regulating container as set forth in the third aspect, in which the electrode of the heat absorbing portion of the Peltier device is constituted so as to be the conductive glass which forms at least a part of the container main body.
According to the above constitution, the following action is obtained in addition to the actions of the third aspect.
(1) Since the electrode of the heat absorbing portion of the Peltier device is the conductive glass which forms at least a part of the container main body, it is possible to easily form the container main body with the Peltier device in an integrated manner. It is also possible to securely cool the container main body which is very small and also securely prevent the electrode from corrosion resulting from chemicals or dew condensation etc., thereby making the Peltier device excellent in reliability and durability.
In this instance, the conductive glass, which acts as the electrode of the heat absorbing portion of the Peltier device, forms at least apart of the container main body and may be directly in contact with a chemical solution or a solution accommodated inside the container main body. Alternatively, the above-described quartz glass, the synthetic resin or the like may be used to form an inner wall portion and laminated on the outer surface thereof. In particular, where the conductive glass acting as the electrode of the heat absorbing portion of the Peltier device is constituted so as to be directly in contact with a chemical solution or a solution accommodated inside the container main body, cooling efficiency is made excellent, the chemical resistance of the container main body may be improved, various types of solutions may be better preserved, the durability and service life are made excellent.
The invention of a fifth aspect is the temperature regulating container as set forth in any one of the second aspect to the forth aspect and constituted so as to have heating means placed on the bottom or the side of the container main body.
According to the above constitution, the following actions are obtained in addition to the action as set forth in any one of the second aspect to the forth aspect.
(1) Since the heating means is placed on the bottom or the side of the container main body, heating efficiency and reliability are made excellent. Further, since the container main body and the heating means may be handled in an integrated manner, the handleability and space saving are made excellent.
(2) Both the Peltier device and the heating means are assembled in the container main body, by which the container main body may be regulated to a desired temperature in a short time. Therefore, the versatility and handleability are made excellent.
In this instance, those using the above-described heat element or the like are preferably used as the heating means.
The invention of a sixth aspect is the temperature regulating container as set forth in the fifth aspect, in which the heat element of the heating means is constituted so as to be the conductive glass which forms at least a part of the container main body.
According to the above constitution, the following action is obtained in addition to the action of the fifth aspect.
(1) Since the heat element of the heating means is the conductive glass which forms at least a part of the container main body, it is possible to easily form the container main body with the heating means in an integrated manner. It is also possible to securely heat the container main body which is very small, thereby securely preventing the heat element from deterioration. Therefore, the heating means is made excellent in reliability and durability.
In this instance, although the conductive glass acting as the heat element of the heating means forms at least a part of the container main body, it may be constituted so as to be directly in contact with a chemical solution or a solution accommodated inside the container main body. Alternatively, the above-described quartz glass, the synthetic resin or the like may be used to form an inner wall portion and laminated on the outer surface thereof. In particular, where the conductive glass acting as the heat element of the heating means is constituted so as to be directly in contact with a chemical solution or a solution accommodated inside the container main body, heating efficiency is made excellent, the chemical resistance of the container main body is improved, various types of solutions are better preserved, the durability and service life are made excellent.
The invention of a seventh aspect is the temperature regulating container as set forth in the sixth aspect which is constituted so as to have an insulation portion for insulating the conductive glass acting as the electrode of the heat absorbing portion of the Peltier device and the conductive glass acting as the heat element of the heating means.
According to the above constitution, the following action is obtained in addition to the action of the sixth aspect.
(1) Provided is the insulation portion for insulating the conductive glass acting as the electrode of the heat absorbing portion of the Peltier device and the conductive glass acting as the heat element of the heating means. Therefore, where the Peltier device and the heating means are driven at the same time, the temperature regulating container is free from any defect and excellent in reliability and safety.
In this instance, the insulation portion may be formed with any material as long as it is able to insulate the conductive glass and another conductive glass and resistant to a chemical solution or a solution accommodated inside the container main body. The previously-described quartz glass or the like is in particular preferably used.
The invention of a eighth aspect is the temperature regulating container as set forth in any one of the third aspect to the seventh aspect, in which the conductive glass is constituted so as to be film-formed on the outer surface of the container main body.
According to the above constitution, the following action is obtained in addition to the action of any one of the third aspect to the seventh aspect.
(1) Since the conductive glass is film-formed on the outer surface of the container main body, it is possible to control the film thickness easily and also to effect heating and cooling uniformly and evenly. Therefore, the container main body is made excellent in stably retaining temperatures.
In this instance, as the method in which the conductive glass may be film-formed on the outer surface of the container main body, preferably used are sputtering, spin coating or brush coating etc. As described above, the quartz glass, the synthetic resin or the like is used to form the inner wall portion of the container main body and the conductive glass may be film-formed on the outer surface thereof.
Sputtering or spin coating may form the conductive glass thinly and evenly, which is efficient in heating and cooling. Further, brush coating may form a thick-filmed conductive glass in a short time, which is excellent in mass production.

EFFECTS OF THE INVENTION

As described so far, the Peltier device of the present invention and the temperature regulating container equipped with the Peltier device are able to provide the following advantageous effects.
According to the invention of the first aspect, the following effect is obtained.
(1) The electrode formed with a conductive glass consisting primarily of vanadate is used, thereby it is possible to provide the Peltier device which is easy in temperature regulation, capable of making a minute regulation of temperatures, excellent in stably retaining temperatures, capable of securely preventing the electrode from corrosion resulting from chemicals or dew condensation etc., excellent in stability of cooling performance, and excellent in reliability and durability of the electrode.
According to the invention of the second aspect, the following effect is obtained.
(1) The Peltier device is placed on the bottom or the side of the container main body, thereby it is possible to provide the temperature regulating container easy in temperature regulation, excellent in stability of cooling action and reliability. Further, the temperature regulating container is excellent in handleability and space saving because the container main body and the Peltier device may be handled in an integrated manner.
According to the invention of the third aspect, the following effects are obtained in addition to the effect described in the second aspect.
(1) The container main body formed with a conductive glass is able to provide the temperature regulating container excellent in thermal conductivity and chemical resistance, capable of preserving various types of chemical solutions or solutions to effectively heat or cool at a temperature regulating portion, and excellent in versatility and reliability.
(2) The conductive glass is processed by using a processing method such as a focused ion beam or the like, thereby it is possible to provide the temperature regulating container capable of forming a very small container main body, excellent in configuration flexibility, easy in miniaturizing the container main body and excellent in space saving.
According to the invention of the forth aspect, the following effect is obtained in addition to the effect of the third aspect.
(1) The conductive glass which forms at least a part of the container main body is allowed to act as the electrode of the heat absorbing portion of the Peltier device, thereby it is possible to provide the temperature regulating container capable of securely cooling the container main body which is very small, improving the handleability and cooling efficiency by handling the container main body and the Peltier device in an integrated manner, securely preventing the electrode from corrosion resulting from chemicals or dew condensation etc., and excellent in reliability and durability.
According to the invention of the fifth aspect, the following effect is obtained in addition to the effect described in any one of the second aspect to the forth aspect.
(1) It is possible to provide the temperature regulating container capable of selectively heating or cooling the container main body by using the Peltier device and the heating means, and regulating the container main body at a desired temperature in a short time, and excellent in versatility and handleability.
According to the invention of the sixth aspect, the following effect is obtained in addition to the effect of the fifth aspect.
(1) The conductive glass which forms at least a part of the container main body is allowed to act as the heat element of the heating means, thereby it is possible to provide the temperature regulating container capable of securely heating the container main body which is very small, improving the handleability and heating efficiency by handling the container main body and the heating means in an integrated manner, securely preventing the heat element from deterioration, and excellent in reliability and durability.
According to the invention of the seventh aspect, the following effect is obtained in addition to the effect of the sixth aspect.
(1) The conductive glass acting as the electrode of the heat absorbing portion of the Peltier device and the conductive glass acting as the heat element of the heating means are insulated by the insulation portion, thereby it is possible to provide a temperature regulating container which is free from any defect and excellent in reliability and safety where the Peltier device and the heating means are driven at the same time.
According to the invention of the eighth aspect, the following effect is obtained in addition to the effect of any one of the third aspect to the seventh aspect.
(1) It is possible to provide the temperature regulating container easy in controlling the film thickness of the conductive glass film-formed on the outer surface of the container main body, excellent in mass production, capable of effecting heating or cooling uniformly and evenly, and excellent in stably retaining temperatures of the container main body.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a side pattern diagram showing the Peltier device of Embodiment 1.

FIG. 2A is a plan view showing a temperature regulating container equipped with the Peltier device of Embodiment 1 and FIG. 2B is an end elevational view taken along line A-A in FIG. 2A.

FIG. 3A is a plan view showing the temperature regulating container of Embodiment 2 and FIG. 3B is an end elevational view taken along line B-B in FIG. 3A.

FIG. 4A is a plan view showing the temperature regulating container of Embodiment 3 and FIG. 4B is an end elevational view taken along line C-C in FIG. 4A.

FIG. 5 is the results of differential thermal analyses made for oxide glasses in Experimental Examples 1 to 3.

FIG. 6 is a graph for plotting the electric conductivity before and after reheating of the oxide glasses of Experimental Examples 1 to 3 which were cooled down to less than the glass transition temperature.

FIG. 7 is a graph showing a relationship between the reheating temperature of the oxide glass of Experimental Example 2, the reheating time and the electric conductivity.

DESCRIPTION OF REFERENCE NUMERALS

1, 1 a Peltier device
2 electrode
3 a N-type thermoelectric semiconductor
3 b P-type thermoelectric semiconductor
4 a, 4 b electrodes
5, 16 variable voltage applying portion
10, 10 a, 10 b temperature regulating container
11, 12, 22 container main body
12 a inner wall portion
12 b, 12 c, 22 b, 22 c peripheral wall portions
12 d, 22 d insulation portion
15 heating means
22 a bottom
30 temperature sensor
30 a temperature sensor fixing portion

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment

1

An explanation will be made for the Peltier device of Embodiment 1 of the present invention by referring to the following drawings.
FIG. 1 is a side pattern diagram showing the Peltier device of Embodiment 1.
In FIG. 1, reference numeral 1 denotes the Peltier device of Embodiment 1 of the present invention, 2 denotes the electrode of the heat absorbing portion of the Peltier device 1 formed with a conductive glass consisting primarily of vanadate, 3 a denotes an N-type thermoelectric semiconductor of the Peltier device 1, one end of which is coupled to the electrode 2 of the heat absorbing portion, 3 b denotes a P-type thermoelectric semiconductor of the Peltier device 1, one end of which is coupled to the electrode 2 of the heat absorbing portion, 4 a and 4 b denote electrodes of heat releasing portions of the Peltier device 1 coupled respectively to the other ends of the N-type thermoelectric semiconductor 3 a and the P-type thermoelectric semiconductor 3 b formed with the conductive glass, and 5 denotes a variable voltage applying portion of the Peltier device 1 for controlling variably direct current flowing from the N-type thermoelectric semiconductor 3 a to the P-type thermoelectric semiconductor 3 b.
The conductive glass which forms the electrode 2 of the heat absorbing portion and the electrodes 4 a, 4 b of the heat releasing portion is an oxide-based glass composition containing vanadium, barium and iron and formed so as to be 3 mm in thickness, with the electric conductivity at a room temperature being from 10⁻⁴to 10⁻¹S·cm⁻¹.
After a powder mixture containing vanadium oxide (V₂O₅) of 60 to 85 mol %, barium oxide (BaO) of 10 to 30 mol % and iron oxide (Fe₂O₃) of 5 to 20 mol % was heated and fused in a platinum crucible or the like, the resultant was rapidly cooled and vitrified. Then, the thus prepared glass composition was retained for a predetermined time at an annealing processing temperature higher than the crystallization temperature but lower than the melting point, thereby regulating the electric conductivity.
An explanation will be made for the thus formed temperature regulating container equipped with the Peltier device of Embodiment 1 by referring to the following drawings.
FIG. 2A is a plan view showing a temperature regulating container equipped with the Peltier device of Embodiment 1, and FIG. 2B is an end elevational view taken along line A-A in FIG. 2A.
In FIG. 2, reference numeral 10 denotes a temperature regulating container equipped with the Peltier device 1 of Embodiment 1 of the present invention, 11 denotes a container main body of the temperature regulating container 10 formed with quartz glass or the like, 30 denotes a temperature sensor for a thermocouple or the like of the temperature regulating container 10 for measuring temperatures of a chemical solution or a solution accommodated inside the container main body 11 fixed on the bottom of the container main body 11, and 30 a denotes a temperature-sensor fixing portion for fixing the temperature sensor 30 to the container main body 11.
A thermal-conductive adhesive agent was used to fix the electrode 2 of the heat absorbing portion of the Peltier device 1 on the side of the container main body 11, thereby suppressing the reduction in thermal conductivity.
An explanation will be made for a method for using the thus constituted temperature regulating container equipped with the Peltier device.
First, a chemical solution or an aqueous solution to be observed or measured is accommodated inside the container main body 11. The temperature sensor 30 is used to measure temperatures of the chemical solution or the solution accommodated inside the container main body 11, then, the controller (not illustrated) is used to control the driving of the Peltier device 1 on the basis of the measured values, thereby cooling and retaining the chemical solution or the solution at any given temperature.
Where the temperature measured by the temperature sensor 30 is in a permissible range of reference set temperatures, the Peltier device 1 will not be driven. Where the temperature is in excess of the permissible range, electric current is controlled at the variable voltage applying portion 5 of the Peltier device 1, cooling is effected so that the temperature of the container main body 11 is in the permissible range of reference set temperatures.
The present embodiment is constituted so as to have one unit of the Peltier device 1 on the side of the container main body 11. However, the Peltier device 1 may be arbitrarily selected for the arrangement and the number of units.
Since the Peltier device of Embodiment 1 is constituted as described above, the following actions are obtained.
(1) The electrode 2 of the heat absorbing portion is formed with a conductive glass consisting primarily of vanadate, thereby making it possible to cool a target substance by changing temperatures slowly. Thus, the target substance is easy in regulating temperatures, capable of retaining temperatures at a high accuracy approximately to a constant level and excellent in stability of cooling temperatures.
(2) Since the electrodes 2, 4 a, 4 b of the Peltier device 1 are formed with a conductive glass consisting primarily of vanadate, it is possible to securely prevent the electrodes 2, 4 a, 4 b from corrosion resulting from chemicals or dew condensation etc. Further, the electrodes 2, 4 a, 4 b are made excellent in reliability and durability.
Since the temperature regulating container equipped with the Peltier device of Embodiment 1 is constituted as described above, the following action is obtained.
(1) Since the temperature regulating container is provided with the Peltier device 1 placed on the side of the container main body 11, it is easy in regulating temperatures, excellent in cooling efficiency and reliability, and excellent in handleability and space saving due to the fact that the container main body 11 and the Peltier device 1 may be handled in an integrated manner.

Embodiment 2

FIG. 3A is a plan view showing the temperature regulating container of Embodiment 2, and FIG. 3B is an end elevational view taken along line B-B in FIG. 3A. It is noted that the components that are identical to or similar to those of Embodiment 1 are given the same reference numerals, and the description thereof is omitted.
In FIG. 3, the temperature regulating container 10 a of Embodiment 2 is different from Embodiment 1 in that the container main body 12 is provided with an insulating inner wall portion 12 a formed with quartz glass or the like and peripheral wall portions 12 b, 12 c film-formed with a conductive glass consisting primarily of vanadate on the outer surface of the inner wall portion 12 a by sputtering, the peripheral wall portions 12 b, 12 c are divided laterally and insulated by an insulation portion 12 d formed with a material similar to the inner wall portion 12 a, and heating means 15 is provided which is placed on the side of the container main body 12, with the peripheral wall portion 12 c formed with the conductive glass given as a heat element. The conductive glass which forms the peripheral wall portion 12 b of the container main body 12 acts as an electrode of the heat absorbing portion of a Peltier device 1 a, by which the Peltier device 1 a is formed integrally with the container main body 12.
It is noted that reference numeral 16 denotes a variable voltage applying portion of the heating means 15 for variably controlling direct current which runs through the conductive glass 12 c.
An explanation will be made for a method for using the thus constituted temperature regulating container.
First, a chemical solution or an aqueous solution to be observed or measured is accommodated inside the container main body 12. The temperature sensor 30 is used to measure temperatures of the chemical solution or the solution accommodated inside the container main body 12, then, the controller (not illustrated) is used to control the driving of the Peltier device 1 a and that of the heating means 15 on the basis of the measured values, thereby regulating and retaining the chemical solution or the solution at any given temperature.
Where the temperature measured by the temperature sensor 30 is in a permissible range of reference set temperatures, the Peltier device 1 a and the heating means 15 will not be driven. Where the temperature is higher than the permissible range, electric current is controlled at the variable voltage applying portion 5 of the Peltier device 1 a to cool the container main body 12. Where the temperature is lower than the permissible range, electric current is controlled at the variable voltage applying portion 16 of the heating means 15 to heat the container main body 12. These motions are repeated, thereby the temperature of the container main body 12 is regulated so as to be in the permissible range of the reference set temperatures.
The material of the insulation portion 12 d is not limited to that used in the present embodiment. Any material may be used as long as it is able to insulate the peripheral wall portions 12 b and 12 c and is resistant to a chemical solution or a solution accommodated inside the container main body 12. Further, in the present embodiment, the left and right peripheral wall portions 12 b, 12 c are divided by the insulation portion 12 d for insulation. However, the peripheral wall portion may be arbitrarily selected for the number of divisions and the divided position. For example, the peripheral wall portion may be vertically divided to which the Peltier device 1 a and the heating means 15 are respectively placed.
The present embodiment is constituted so as to have one unit of the Peltier device 1 a and one unit of the heating means 15 on a plane to which the container main body 12 faces. However, the Peltier device 1 a and the heating means 15 may be arbitrarily selected for the arrangement and the number of units.
It is noted that the temperature-sensor fixing portion 30 a may be formed integrally with the insulation portion 12 d or may be formed by another insulating member.
Since the temperature regulating container equipped with the Peltier device of Embodiment 2 is constituted as described above, the following actions are obtained in addition to the action of Embodiment 1.
(1) Since the peripheral wall portions 12 b, 12 c of the container main body 12 are formed with a conductive glass, it is possible to improve the thermal conductivity. Therefore, the temperature regulating container is able to preserve various types of chemical solutions or solutions and effectively heat and cool them at the temperature regulating portion and is excellent in versatility and reliability.
(2) Since the electrode of the heat absorbing portion of the Peltier device 1 a is a peripheral wall portion 12 b of the container main body 12 formed with the conductive glass, it is possible to easily form the container main body 12 with the Peltier device 1 a in an integrated manner. It is also possible to securely cool the container main body 12 which is very small and also securely prevent the electrode from corrosion resulting from chemicals or dew condensation etc., thereby making the Peltier device 1 a excellent in reliability and durability.
(3) Since the heating means 15 is placed on the side of the container main body 12, it is possible to heat the container main body 12 simply and securely. Therefore, heating efficiency and reliability are made excellent.
(4) Since the heat element of the heating means 15 is the peripheral wall portion 12 c of the container main body 12 formed with a conductive glass, it is possible to easily form the container main body 12 with the heating means 15 in an integrated manner. It is also possible to securely heat the container main body 12 which is very small, thereby securely preventing the heat element from deterioration. Therefore, the heating means 15 is made excellent in reliability and durability.
(5) Both the Peltier device 1 a and the heating means 15 are assembled in the container main body 12, by which the container main body 12 may be regulated to a desired temperature in a short time. Therefore, the versatility and handleability are made excellent.
(6) There is provided the insulation portion 12 d for insulating the peripheral wall portion 12 b made with a conductive glass acting as the electrode of the heat absorbing portion of the Peltier device 1 a and the peripheral wall portion 12 c made with a conductive glass acting as the heat element of the heating means 15, by which the temperature regulating container is free from any defect and excellent in reliability and safety where the Peltier device 1 a and the heating means 15 are driven at the same time.
(7) Since the conductive glass which forms the peripheral wall portions 12 b, 12 c consists primarily of vanadate, the electrical conductivity may be increased to effect cooling by the Peltier device 1 a and improve heating efficiency by the heating means 15. Therefore, the temperature regulating container is excellent in energy saving.
(8) Since the peripheral wall portions 12 b, 12 c made with the conductive glass are film-formed on the outer surface of the inner wall portion 12 a of the container main body 12, it is possible to control the film thickness of the peripheral wall portions 12 b, 12 c easily and also to effect heating and cooling uniformly and evenly. Therefore, the container main body 12 is made excellent in stably retaining temperatures.

Embodiment 3

FIG. 4A is a plan view showing the temperature regulating container of Embodiment 3, and FIG. 4B is an end elevational view taken along the line C-C in FIG. 4A. It is noted that the components that are identical to or similar to those of Embodiment 2 are given the same reference numerals, and description thereof is omitted.
In FIG. 4, the temperature regulating container 10 b of Embodiment 3 is different from Embodiment 2 in that the container main body 22 is provided with an insulating bottom 22 a formed with quartz glass or the like and peripheral wall portions 22 b, 22 c formed with the conductive glass similar to that of Embodiment 2, and the peripheral wall portions 22 b, 22C are divided laterally by the insulation portion 22 d formed with a material similar to that of the bottom 22 a for insulation.
A method for using the temperature regulating container of Embodiment 3 is similar to that of Embodiment 2, and the description thereof is be omitted.
Since the temperature regulating container of Embodiment 3 is constituted as described above, the following actions are obtained in addition to the action of Embodiment 3.
(1) Since the peripheral wall portions 22 b, 22 c of the container main body 22 are formed with conductive glass, they may be subjected to fine processing by using a processing method such as a focused ion beam and excellent in configuration flexibility, easy in miniaturizing the container main body 22 and excellent in space saving.
(2) Since the conductive glass consists primarily of vanadate, there is provided the container main body 22 which may be easily formed into a complicated configuration, excellent in processability and available in various forms. The container main body 22 is also easily made small in size and light in weight and therefore excellent in resource saving and mass production.

EXAMPLES

Hereinafter, a description will be made more specifically for the present invention by referring to examples. It is noted that the present invention shall not be limited to these examples.

Experimental Example 1

Respective reagents (special grade) were weighed so that barium oxide (BaO) was 10 mol %, divanadium pentaoxide (V₂O₅) was 80 mol % and di-iron trioxide (Fe₂O₃) was 10 mol %, that is, a total of 10 g, and mixed in an agate mortar. Thereafter, the resultant was placed in a platinum crucible, and the mixture in the platinum crucible was heated in an electric furnace, the temperature of which was elevated to 1,000° C. for 90 minutes in the atmosphere and fused. A fused material was allowed to flow on a 10 mm-thick stainless steel plate and rapidly cooled to a temperature lower than the glass transition temperature, thereby obtaining the oxide glass of Experimental Example 1.

Experimental Example 2

The oxide glass of Experimental Example 2 was obtained by procedures similar to those of Experimental Example 1 except that respective reagents (special grade) were weighed so that barium oxide (BaO) was 20 mol %, divanadium pentaoxide (V₂O₅) was 70 mol % and di-iron trioxide (Fe₂O₃) was 10 mol %, that is, a total of 10 g.

Experimental Example 3

The oxide glass of Experimental Example 3 was obtained by procedures similar to those of Experimental Example 1 except that respective reagents (special grade) were weighed so that barium oxide (BaO) was 30 mol %, divanadium pentaoxide (V₂O₅) was 60 mol % and di-iron trioxide (Fe₂O₃) was 10 mol %, that is, a total of 10 g.

(Results of Differential Thermal Analysis of Oxide Glasses of Experimental Examples 1 to 3)

Differential thermal analysis (DTA) was made for the oxide glasses of Experimental Example 1 to 3. More particularly, the differential thermal analysis (DTA) was made at a temperature elevating rate of 10° C./min in a nitrogen atmosphere, with α aluminium oxide used as a reference material.
FIG. 5 shows the results of differential thermal analysis of the oxide glasses of Experimental Examples 1 to 3.
As shown in FIG. 5, the glass transition temperature (Tg) and the crystallization temperature (Tc) were increased with an increase in the molar ratio of barium oxide and a decrease in the molar ratio of divanadium pentaoxide. The crystallization temperature Tc was 362° C. in Experimental Example 1, 392° C. in Experimental Example 2 and 433° C. in Experimental Example 3. A sharp endothermic peak found at a temperature range exceeding the crystallization temperature (Tc) was suggestive of a melting point, and the melting point was 600° C. or higher in Experimental Example 1, 540° C. in Experimental Example 2 and 563° C. in Experimental Example 3.

(Relationship Between Reheating Temperature and Electric Conductivity)

The oxide glasses of Experimental Examples 1 to 3 cooled to a temperature lower than the glass transition temperature were reheated for one hour in an atmosphere at the respective temperatures of 350° C., 400° C., 500° C. and 550° C., thereby the electric conductivity of the oxide glasses before and after reheating was measured at 25° C. by a direct current four-electrode method.
FIG. 6 is a graph for plotting the electric conductivity before and after reheating of the oxide glasses of Experimental Examples 1 to 3 cooled to a temperature lower than the glass transition temperature. In FIG. 6, the horizontal axis indicates the reheating temperature (° C.), while the longitudinal axis indicates the electric conductivity σ (S·cm⁻¹) at 25° C.
As shown in FIG. 6, where the oxide glass of Experimental Example 1 was reheated for one hour at 500 to 550° C., a temperature range in excess of the crystallization temperature (362° C.) but lower than the melting point (600° C. or higher), the electric conductivity at 25° C. could be increased by approximately four digits as compared with the conductivity before reheating.
The electric conductivity reheated for one hour at 400° C. in FIG. 6 remained unchanged as compared with that before reheating. However, after reheating for two hours at 400° C., the electric conductivity at a room temperature (25° C.) could be increased to about 10⁻³S·cm⁻¹. In the oxide glass of Experimental Example 1, one-hour retention time at the reheating temperature of 400° C. was thought to be insufficient.
Further, as shown in FIG. 6, where the oxide glass of Experimental Example 2 was reheated for one hour at 400 to 500° C., a temperature range in excess of the crystallization temperature (392° C.) but lower than the melting point (540° C.), the electric conductivity at 25° C. could be increased to a higher level of 10⁻³S·cm⁻¹or more. In particular, where the oxide glass was reheated at 500° C., the electric conductivity could be increased to a higher level of 10⁻¹S·cm⁻¹or more. It is noted that where the oxide glass was reheated for one hour at 550° C., a temperature higher than the melting point (540° C.), it was partially crystallized.
Still further, as shown in FIG. 6, where the oxide glass of Experimental Example 3 was reheated at 500° C., a temperature in excess of the crystallization temperature (433° C.) but lower than the melting point (563° C.), the electric conductivity at 25° C. could be increased to a higher level of 10⁻²S·cm⁻¹or more.
Where the oxide glass was reheated for one hour at 550° C., a temperature close to the melting point (563° C.), it was partially crystallized. Therefore, the electric conductivity of oxide glass reheated at 550° C. was not plotted. This crystallization was inferred due to an increased molar ratio of barium oxide to divanadium pentaoxide. Where the oxide glass was reheated for a shorter retention time, or 0.5 hours at 550° C., it was not crystallized. Therefore, the electric conductivity at 25° C. could be increased to about 10⁻²S·cm⁻¹.
As described so far, it was apparent that after a reheating step where the oxide glass (conductive glass) was retained at a temperature range in excess of the crystallization temperature but lower than the melting point, the electric conductivity at a room temperature (25° C.) could be drastically increased. Further, it was found that the electric conductivity was improved with an increase in the reheating temperature within a temperature range at which no crystallization or fusion was found conspicuously. It was also found that a shorter retention time was acceptable at a higher reheating temperature. On the basis of these findings, a mechanism by which the electric conductivity is improved on reheating at a temperature range in excess of the crystallization temperature but lower than the melting point is considered due to activated energy of electrons.
In addition to these experimental examples, various types of oxide glasses were prepared so that the molar ratio of vanadium oxide (V₂O₅), barium oxide (BaO), iron oxide (Fe₂O₃) would fall under the respective ranges of 40 to 98 mol %, 1 to 40 mol % and 1 to 20 mol %, thereby measuring the respective crystallization temperatures and melting points to obtain the electric conductivity at a room temperature before and after a reheating step. It was confirmed that as with these experimental examples, the electric conductivity was increased after the reheating step.
Further, it was confirmed that the oxide glass produced by fusing and cooling a mixture of vanadium oxide (V₂O₅), diphosphate pentaoxide (P₂O₅) and barium oxide (BaO) and the oxide glass produced by fusing and cooling a mixture of vanadium oxide (V₂O₅), potassium oxide (K₂O) and iron oxide (Fe₂O₃) were increased in electric conductivity after the reheating step, in addition to the oxide glass produced by fusing and cooling a mixture of vanadium oxide (V₂O₅), barium oxide (BaO) and iron oxide (Fe₂O₃).

(Relationship Between Reheating Time and Electric Conductivity)

Example 1

The oxide glass of Experimental Example 2 cooled to a temperature lower than the glass transition temperature was reheated at 500° C., a temperature in excess of the crystallization temperature (392° C.) but lower than the melting point (540° C.) in an atmosphere and taken out from a furnace at every predetermined time, by which the electric conductivity at 25° C. was measured.

Example 2

The oxide glass of Experimental Example 2 cooled to a temperature lower than the glass transition temperature was reheated at 400° C., a temperature in excess of the crystallization temperature (392° C.) but lower than the melting point (540° C.) in an atmosphere, and taken out from a furnace at every predetermined time, by which the electric conductivity at 25° C. was measured.

Example 3

The oxide glass of Experimental Example 2 cooled to a temperature lower than the glass transition temperature was reheated at 350° C., a temperature higher than the glass transition temperature (328° C.) but lower than the crystallization temperature (392° C.) in an atmosphere, and taken out from a furnace at every predetermined time, by which the electric conductivity at 25° C. was measured.
FIG. 7 is a graph showing a relationship between the reheating temperature of the oxide glass of Experimental Example 2, the reheating time and the electric conductivity. In FIG. 3, the horizontal axis indicates the retention time at a reheating temperature, while the longitudinal axis indicates the electric conductivity σ (S·cm⁻¹) at 25° C.
In Examples 1 and 2 where the oxide glass of Experimental Example 2 cooled to a temperature lower than the glass transition temperature was reheated at a temperature in excess of the crystallization temperature (392° C.) but lower than the melting point (540° C.) in an atmosphere, it was confirmed that only 30-minute reheating could increase the electric conductivity by three digits or more and continuous reheating barely changed the electric conductivity. It was also confirmed that Example 1 where the reheating temperature was higher than Example 2 could increase the electric conductivity.
On the other hand, in Example 3 where the oxide glass was reheated at a temperature higher than the glass transition temperature (328° C.) but lower than the crystallization temperature (392° C.), it was confirmed that the electric conductivity was increased with an increase in the retention time at the reheating temperature and no electric conductivity could be kept constant unless the oxide glass was retained for 180 minutes or longer. It was also confirmed that the electric conductivity of Example 3 was lower by one digit or more than the electric conductivity of Example 1 and that of Example 2.
As described so far, according to the present example, the oxide glass is retained for an appropriate time at a reheating temperature, according to the reheating temperature, thereby preventing a variance in electric conductivity. In particular, according to Examples 1 and 2, only if it is retained at a predetermined temperature range for a short time, about 30 minutes, is it possible that the electric conductivity is increased drastically. Further, it became clear that even if there is any change in retention time, the electric conductivity is changed to a slight extent, and the stability of productivity is quite excellent and preferable. It became also clear that the heating time and others are changed in a reheating step, by which the extent of electric conductivity of vanadate glass at a room temperature may be designed in a range of 10⁻⁴S·cm⁻¹or more and controlled at a high accuracy.
It has been found that when the thus obtained conductive glass is used as an electrode of a Peltier device, temperatures may be set minutely with a gradual change in temperature, a target substance may be kept accurately at a temperature approximately in a constant range, and excellent in stability of cooling performance.

INDUSTRIAL APPLICABILITY

The present invention is to provide a Peltier device capable of retaining a certain temperature at a high accuracy by using a conductive glass consisting primarily of vanadate as an electrode, easy in temperature regulation and excellent in handleability and also to provide a temperature regulating container equipped with the Peltier device which is easy in processing the container main body, excellent in configuration flexibility, capable of forming a very small space to accommodate a chemical solution or an aqueous solution etc., excellent in chemical resistance and preservability, capable of effectively heating or cooling a very small space at which the chemical solution or the aqueous solution etc., is accommodated and retaining it at any given temperature, thereby making observations and various measurements etc., effectively in a short time and excellent in reliability, versatility and workability. Thereby, it is possible to improve the handleability of a chemical solution or an aqueous solution etc., in industrial fields such as biotechnology and medicine.

Claims

1. A Peltier device having a heat absorbing portion and a heat emitting portion, wherein at least an electrode of the heat absorbing portion is formed with a conductive glass consisting primarily of vanadate.

2. A temperature regulating container having a container main body and the Peltier device as set forth in claim 1 which is placed on the bottom or the side of the container main body.

3. The temperature regulating container as set forth in claim 2, wherein the container main body is at least partially formed with the conductive glass.

4. The temperature regulating container as set forth in claim 3, wherein the electrode of the heat absorbing portion of the Peltier device is the conductive glass which forms at least a part of the container main body.

5. The temperature regulating container as set forth in any one of claim 2 to claim 4, which has heating means placed on the bottom or the side of the container main body.

6. The temperature regulating container as set forth in claim 5, wherein the heat element of the heating means is the conductive glass which forms at least a part of the container main body.

7. The temperature regulating container as set forth in claim 6 which has an insulation portion for insulating the conductive glass acting as the electrode of the heat absorbing portion of the Peltier device and the conductive glass acting as the heat element of the heating means.

8. The temperature regulating container as set forth in any one of claim 3 to claim 7, wherein the conductive glass is film-formed on the outer surface of the container main body.