JP6256596B2 - Vanadium oxide and method for producing the same - Google Patents

Vanadium oxide and method for producing the same Download PDF

Info

Publication number
JP6256596B2
JP6256596B2 JP2016511327A JP2016511327A JP6256596B2 JP 6256596 B2 JP6256596 B2 JP 6256596B2 JP 2016511327 A JP2016511327 A JP 2016511327A JP 2016511327 A JP2016511327 A JP 2016511327A JP 6256596 B2 JP6256596 B2 JP 6256596B2
Authority
JP
Japan
Prior art keywords
vanadium
temperature
vanadium oxide
particle size
present
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
JP2016511327A
Other languages
Japanese (ja)
Other versions
JPWO2015151355A1 (en
Inventor
廣瀬　左京
左京 廣瀬
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Murata Manufacturing Co Ltd
Original Assignee
Murata Manufacturing Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Murata Manufacturing Co Ltd filed Critical Murata Manufacturing Co Ltd
Publication of JPWO2015151355A1 publication Critical patent/JPWO2015151355A1/en
Application granted granted Critical
Publication of JP6256596B2 publication Critical patent/JP6256596B2/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G31/00—Compounds of vanadium
    • C01G31/02—Oxides
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K5/00—Heat-transfer, heat-exchange or heat-storage materials, e.g. refrigerants; Materials for the production of heat or cold by chemical reactions other than by combustion
    • C09K5/08—Materials not undergoing a change of physical state when used
    • C09K5/14—Solid materials, e.g. powdery or granular
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2002/00—Crystal-structural characteristics
    • C01P2002/50—Solid solutions
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2002/00—Crystal-structural characteristics
    • C01P2002/50—Solid solutions
    • C01P2002/52—Solid solutions containing elements as dopants
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2002/00—Crystal-structural characteristics
    • C01P2002/70—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data
    • C01P2002/72—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data by d-values or two theta-values, e.g. as X-ray diagram
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/60—Particles characterised by their size
    • C01P2004/61—Micrometer sized, i.e. from 1-100 micrometer

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Combustion & Propulsion (AREA)
  • Thermal Sciences (AREA)
  • Materials Engineering (AREA)
  • Inorganic Chemistry (AREA)
  • Inorganic Compounds Of Heavy Metals (AREA)

Description

本発明は、酸化バナジウムおよびその製造方法に関する。   The present invention relates to vanadium oxide and a method for producing the same.

バナジウムの酸化物として、Ｖ２Ｏ３、ＶＯ２、Ｖ２Ｏ５等の種々のものが存在することが知られている。中でもＶＯ２は、電子相転移する物質として知られており、この電子相転移に伴う潜熱を利用して、蓄熱材としての使用が提案されている（特許文献１）。It is known that various oxides such as V 2 O 3 , VO 2 , and V 2 O 5 exist as vanadium oxides. Among these, VO 2 is known as a substance that undergoes an electronic phase transition, and its use as a heat storage material has been proposed using the latent heat associated with this electronic phase transition (Patent Document 1).

特開２０１０−１６３５１０号公報JP 2010-163510 A

本発明者は、上記のように蓄熱材として用いられている酸化バナジウムを、電子機器の冷却に利用できることを見出した。効率良い冷却のために、潜熱の大きい高純度のＶＯ２が必要になるが、酸化バナジウムには、酸素含有量、バナジウム価数の異なる相が存在する為、このような高純度のＶＯ２は、小規模では製造可能であっても、多量に安定して製造することは困難であった。特に、市販のＶＯ２は、一般的にＮＨ４ＶＯ３を、４価のバナジウムが安定となる雰囲気下で熱処理することにより製造されているが、単にこのような雰囲気下で加熱することにより得られたＶＯ２は、冷却デバイスに用いるには吸熱量が小さいことが判った。The present inventor has found that vanadium oxide used as a heat storage material as described above can be used for cooling electronic devices. For efficient cooling, high-purity VO 2 with large latent heat is required. However, since vanadium oxide has phases with different oxygen contents and vanadium valences, such high-purity VO 2 Even if it can be produced on a small scale, it has been difficult to produce a large amount stably. In particular, commercially available VO 2 is generally produced by heat-treating NH 4 VO 3 in an atmosphere in which tetravalent vanadium is stable, but is obtained by simply heating in such an atmosphere. It was found that the obtained VO 2 had a small endotherm for use in a cooling device.

さらに、本発明者は、高純度かつ粉末Ｘ線回折測定において、同程度の優れた結晶性を示すＶＯ２であっても、吸熱量が大きく異なること、即ち、同じ単相のＶＯ２であっても、吸熱量に差があることを見出した。Further, the present inventor has found that even in the case of VO 2 having high purity and powder X-ray diffraction measurement, the endothermic amount is greatly different, that is, the same single-phase VO 2. However, it has been found that there is a difference in the endothermic amount.

従って、本発明の目的は、吸熱量が大きな酸化バナジウム、およびこのような酸化バナジウムを多量に安定して製造できる方法を提供することにある。   Accordingly, an object of the present invention is to provide vanadium oxide having a large endothermic amount and a method capable of stably producing a large amount of such vanadium oxide.

本発明者は、酸化バナジウムについて、粉末Ｘ線回折により測定される結晶性が同程度であっても、粒径が異なる場合には吸熱性が異なること、即ち、吸熱性が粒径により影響を受けることを見出し、さらに検討した結果、メジアン径が２μｍ以上である場合に、優れた吸熱性を示すことを見出した。   The present inventor found that vanadium oxide has different endothermic properties when the particle size is different, even if the crystallinity measured by powder X-ray diffraction is the same, that is, the endothermic property is affected by the particle size. As a result of further investigation, it was found that when the median diameter is 2 μm or more, excellent endothermic properties are exhibited.

また、特に優れた吸熱性を有する酸化バナジウム粒子は、合成時の酸素分圧および温度を制御することにより得られることを見出した。   It has also been found that vanadium oxide particles having particularly excellent endothermic properties can be obtained by controlling the oxygen partial pressure and temperature during synthesis.

本発明の第１の要旨によれば、メジアン径が２μｍ以上である、４価のバナジウム（Ｖ４＋）の酸化物を主成分とする酸化バナジウム粒子が提供される。According to the first aspect of the present invention, there is provided vanadium oxide particles whose main component is an oxide of tetravalent vanadium (V 4+ ) having a median diameter of 2 μm or more.

本発明の第２の要旨によれば、上記の酸化バナジウム粒子を含む材料が提供される。   According to a second aspect of the present invention, there is provided a material containing the above vanadium oxide particles.

本発明の第３の要旨によれば、上記の酸化バナジウム粒子の製造方法であって：
（１）少なくとも１種の２価〜５価のバナジウムの酸化物、および所望により少なくとも１種のＭ（ここに、Ｍは、Ｗ、Ｔａ、ＭｏおよびＮｂから選択される）の酸化物を含む原料を、８５０℃以上１２００℃以下の温度にまで加熱する昇温工程；と
（２）昇温後の温度で保持する高温保持工程と
を含み、昇温工程において、８００℃での酸素分圧が、１×１０−１１ＭＰａ以下であり、高温保持工程の少なくとも一部期間において、酸素分圧が、１×１０−７〜１×１０−１０ＭＰａである方法が提供される。According to a third aspect of the present invention, there is provided a method for producing the vanadium oxide particles as described above:
(1) including at least one divalent to pentavalent oxide of vanadium and optionally at least one oxide of M (where M is selected from W, Ta, Mo and Nb) A temperature raising step for heating the raw material to a temperature of 850 ° C. or higher and 1200 ° C. or lower; and (2) a high temperature holding step for holding the raw material at a temperature after the temperature rising, and in the temperature rising step, an oxygen partial pressure at 800 ° C. Is 1 × 10 −11 MPa or less, and a method in which the oxygen partial pressure is 1 × 10 −7 to 1 × 10 −10 MPa in at least a part of the high temperature holding step is provided.

本発明によれば、吸熱量の大きい酸化バナジウム粒子が提供される。また、本発明によれば、このようなバナジウム粒子を、大量に安定して合成することが可能になる。   According to the present invention, vanadium oxide particles having a large endothermic amount are provided. Moreover, according to the present invention, it is possible to stably synthesize such vanadium particles in a large amount.

図１は、実施例で用いた「さや」の概略斜視図である。FIG. 1 is a schematic perspective view of a “sheath” used in the examples. 図２は、実施例における表面部、中央部および底面部を説明する、ＶＯｘを充填した図１のさやの概略断面図である。FIG. 2 is a schematic cross-sectional view of the sheath of FIG. 1 filled with VO x for explaining a surface portion, a center portion, and a bottom surface portion in the embodiment. 図３は、試料番号１および２のＶＯ２の粉末Ｘ線回折測定の結果を示す。FIG. 3 shows the results of powder X-ray diffraction measurement of VO 2 of sample numbers 1 and 2. 図４は、試料番号１〜１５の吸熱量とメジアン径の関係を示すグラフである。FIG. 4 is a graph showing the relationship between the endothermic amount and the median diameter of sample numbers 1 to 15.

本発明の酸化バナジウム粒子は、４価のバナジウム（Ｖ４＋）の酸化物、即ちＶＯ２を主成分とする。The vanadium oxide particles of the present invention contain a tetravalent vanadium (V 4+ ) oxide, that is, VO 2 as a main component.

ここで、主成分とは、酸化バナジウム粒子中に９０質量％以上含まれる成分を意味し、特に９５質量％以上、好ましくは９８質量％以上、より好ましくは９８質量％以上、例えば９８．０〜９９．８質量％または実質的に１００重量％含むことを意味する。また、主成分とは、酸化バナジウム粒子が実質的にその成分からなることも含む。その他の成分としては、４価以外のバナジウムの酸化物、具体的には、限定するものではないが、ＶＯ、Ｖ２Ｏ３、Ｖ２Ｏ５、Ｖ３Ｏ７、Ｖ４Ｏ７、Ｖ５Ｏ９、Ｖ６Ｏ１１、およびＶ６Ｏ１３等が挙げられる。Here, the main component means a component contained in the vanadium oxide particles by 90% by mass or more, particularly 95% by mass or more, preferably 98% by mass or more, more preferably 98% by mass or more, for example, 98.0. It means 99.8% by mass or substantially 100% by weight. The main component includes that the vanadium oxide particles are substantially composed of the component. Other components include oxides of vanadium other than tetravalent, specifically, but not limited to VO, V 2 O 3 , V 2 O 5 , V 3 O 7 , V 4 O 7 , V 5 O 9 , V 6 O 11 , V 6 O 13 and the like.

一の態様において、本発明の酸化バナジウム粒子は、他の原子、例えば、Ｗ、Ｔａ、ＭｏおよびＮｂから成る群から選択される１種またはそれ以上の原子を含んでいてもよい。このような原子を含ませる（ドープする）ことにより、酸化バナジウムが相転移する温度を調節することができる。   In one embodiment, the vanadium oxide particles of the present invention may contain other atoms, such as one or more atoms selected from the group consisting of W, Ta, Mo and Nb. By including (doping) such atoms, the temperature at which vanadium oxide undergoes phase transition can be adjusted.

好ましくは、本発明の酸化バナジウム粒子は、ＶおよびＭ（ここに、Ｍは、Ｗ、Ｔａ、ＭｏおよびＮｂから選択される少なくとも一種である）を含み、ＶとＭの合計を１００モル部としたときのＭの含有モル部が０モル部以上約５モル部以下である酸化物を含む。なお、Ｍは必須成分ではなく、Ｍの含有モル部は０であってもよい。   Preferably, the vanadium oxide particles of the present invention contain V and M (wherein M is at least one selected from W, Ta, Mo and Nb), and the sum of V and M is 100 mol parts. In this case, the oxide contains an oxide in which the molar part of M is 0 to about 5 parts by mole. Note that M is not an essential component, and the content molar part of M may be 0.

別の好ましい態様において、本発明の酸化バナジウム粒子は、式：
Ｖ１−ｘＭｘＯ２
（式中、Ｍは、Ｗ、Ｔａ、ＭｏまたはＮｂであり、ｘは、０以上０．０５以下である）
で表される１種またはそれ以上の酸化物を含む。In another preferred embodiment, the vanadium oxide particles of the present invention have the formula:
V 1-x M x O 2
(In the formula, M is W, Ta, Mo or Nb, and x is 0 or more and 0.05 or less)
Or one or more oxides represented by:

本発明の酸化バナジウム粒子は、メジアン径が２μｍ以上、好ましくは１０μｍ以上である。メジアン径が２μｍ以上である酸化バナジウム粒子は、吸熱量が大きく、メジアン径が大きくなるに従い、より吸熱量が大きくなる（図４参照）。   The vanadium oxide particles of the present invention have a median diameter of 2 μm or more, preferably 10 μm or more. The vanadium oxide particles having a median diameter of 2 μm or more have a large endothermic amount, and the endothermic amount increases as the median diameter increases (see FIG. 4).

本明細書において、酸化バナジウム粒子の「メジアン径」とは、体積基準で粒度分布を求め、全体積を１００％とした累積曲線において、累積値が５０％となる点の粒径と定義される。かかる平均粒子径は、レーザー回折・散乱式 粒子径・粒度分布測定装置を用いて測定することができる。   In the present specification, the “median diameter” of vanadium oxide particles is defined as the particle diameter at which the cumulative value is 50% in a cumulative curve obtained by obtaining the particle size distribution on a volume basis and setting the total volume to 100%. . The average particle size can be measured using a laser diffraction / scattering particle size / particle size distribution measuring apparatus.

本発明の酸化バナジウムは、実質的にＶＯ２からなる場合、好ましくは４０Ｊ／ｇ以上、より好ましくは５０Ｊ／ｇ以上、さらに好ましくは６０Ｊ／ｇ以上の吸熱量を有し得る。他の元素、例えばＷがドープされている場合は、吸熱量は変化し得、例えば、好ましくは３０Ｊ／ｇ以上、より好ましくは４０Ｊ／ｇ以上、さらに好ましくは４５Ｊ／ｇ以上の吸熱量を有し得る。When the vanadium oxide of the present invention is substantially composed of VO 2 , it may have an endothermic amount of preferably 40 J / g or more, more preferably 50 J / g or more, and even more preferably 60 J / g or more. When other elements, such as W, are doped, the endotherm can change, for example, preferably has an endotherm of 30 J / g or more, more preferably 40 J / g or more, and even more preferably 45 J / g or more. Can do.

吸熱量は、示差走査熱量測定（ＤＳＣ：Differential scanning calorimetry）により測定することができる。   The endothermic amount can be measured by differential scanning calorimetry (DSC).

一の要旨において、本発明は、上記の酸化バナジウム粒子を含む材料を提供する。かかる材料は、特に限定されないが、電子機器の冷却デバイス、蓄熱材などに用いることができる。   In one aspect, the present invention provides a material comprising the vanadium oxide particles described above. Such a material is not particularly limited, but can be used for a cooling device of electronic equipment, a heat storage material, and the like.

一の要旨において、本発明は、優れた吸熱性を有する酸化バナジウム粒子の製造方法を提供する。   In one aspect, the present invention provides a method for producing vanadium oxide particles having excellent endothermic properties.

本発明の方法は、（１）昇温工程と（２）高温保持工程を含む。   The method of the present invention includes (1) a temperature raising step and (2) a high temperature holding step.

以下、昇温工程について説明する。   Hereinafter, the temperature raising step will be described.

まず、２価〜５価のバナジウムの酸化物および単体のバナジウムからなる群から選択される少なくとも１種、および所望により少なくとも１種のＭ（ここに、Ｍは、Ｗ、Ｔａ、ＭｏおよびＮｂから選択される）の酸化物を含む原料を準備する。この原料は、粉末であることが好ましい。   First, at least one selected from the group consisting of bivalent to pentavalent oxides of vanadium and simple vanadium, and optionally at least one M (where M is W, Ta, Mo and Nb). A raw material containing a selected oxide). This raw material is preferably a powder.

上記原料は、種々の酸化バナジウムを含んでいてもよく、例えば、ＶＯ、Ｖ２Ｏ３、Ｖ２Ｏ５、Ｖ３Ｏ７、Ｖ４Ｏ７、Ｖ５Ｏ９、Ｖ６Ｏ１１、およびＶ６Ｏ１３等を含んでいてもよい。また、ＶＯ２、特に粒径が２μｍ未満であるＶＯ２も原料として用いることができる。The raw materials may contain various vanadium oxides, such as VO, V 2 O 3 , V 2 O 5 , V 3 O 7 , V 4 O 7 , V 5 O 9 , V 6 O 11 , and V 6 O 13 or the like may be included. Moreover, VO 2, in particular the particle size can be used as VO 2 also raw material is less than 2 [mu] m.

さらに、上記原料は、他の元素、例えばＷ、Ｔａ、ＭｏおよびＮｂから選択される１種またはそれ以上の元素を含んでいてもよい。これらの元素は、好ましくは、酸化物として、例えばＷＯ３、Ｔａ２Ｏ５、ＭｏＯ３、Ｎｂ２Ｏ５として含まれ得る。Furthermore, the raw material may contain one or more elements selected from other elements such as W, Ta, Mo and Nb. These elements can preferably be included as oxides, for example as WO 3 , Ta 2 O 5 , MoO 3 , Nb 2 O 5 .

好ましい態様において、原料中に含まれるＶとＯのモル比は、約１：２である。このような比とすることにより、ＶＯ２への変化を促すことができる。In a preferred embodiment, the molar ratio of V and O contained in the raw material is about 1: 2. With such a ratio, it is possible to prompt a change in the VO 2.

次に、上記原料を、還元雰囲気下で徐々に昇温（加熱）する。   Next, the raw material is gradually heated (heated) in a reducing atmosphere.

昇温は、原料の温度が、８５０℃以上１２００℃以下の温度、好ましくは９００℃以上１１００℃以下に達するまで行われる。   The temperature rise is performed until the temperature of the raw material reaches a temperature of 850 ° C. or higher and 1200 ° C. or lower, preferably 900 ° C. or higher and 1100 ° C. or lower.

昇温工程は、特に限定されないが、例えば、１〜１０時間、好ましくは３〜６時間で行われる。   Although a temperature rising process is not specifically limited, For example, it is performed for 1 to 10 hours, Preferably it is 3 to 6 hours.

昇温工程は、より強い還元雰囲気下で行われ、酸素分圧は、高温保持工程より昇温工程の方が低い。好ましくは、昇温工程における８００℃での酸素分圧は、１×１０−１１ＭＰａ以下であり、より好ましくは１×１０−１２ＭＰａ以下である。このような酸素分圧とすることにより、融点の低いＶ２Ｏ５（約８００℃）が、より融点の高い価数の小さい酸化バナジウム、例えばＶＯ２やＶ２Ｏ３等になりやすくなるので、昇温工程における原料の溶融等を防止することができる。その結果、原料粒子同士のネッキング等が防止され、また、反応系における酸素濃度がより均一に保たれ、純度の高い酸化バナジウムを得ることができる。The temperature raising step is performed in a stronger reducing atmosphere, and the oxygen partial pressure is lower in the temperature raising step than in the high temperature holding step. Preferably, the oxygen partial pressure at 800 ° C. in the temperature raising step is 1 × 10 −11 MPa or less, more preferably 1 × 10 −12 MPa or less. By setting such an oxygen partial pressure, V 2 O 5 having a low melting point (about 800 ° C.) is likely to become a vanadium oxide having a higher melting point and a lower valence, such as VO 2 or V 2 O 3 . The melting of the raw material in the temperature raising step can be prevented. As a result, necking or the like between the raw material particles is prevented, the oxygen concentration in the reaction system is kept more uniform, and vanadium oxide with high purity can be obtained.

従って、一の態様において、原料は、Ｖ２Ｏ５を含む。Thus, in one embodiment, the raw material includes V 2 O 5 .

昇温工程における酸素濃度は、高温保持工程の酸素濃度より低く、その時点の温度でバナジウムが４価よりも還元される酸素濃度であってもよく、必ずしも一定である必要はない。例えば、より低温時には、比較的低い酸素濃度とし、高温になるに従って、徐々に酸素濃度を高くしてもよく、その逆でもよい。   The oxygen concentration in the temperature raising step may be lower than the oxygen concentration in the high temperature holding step, and may be an oxygen concentration at which vanadium is reduced to less than tetravalent at the temperature at that time, and is not necessarily constant. For example, at a lower temperature, the oxygen concentration may be relatively low, and the oxygen concentration may be gradually increased as the temperature increases, and vice versa.

以下、高温保持工程について説明する。   Hereinafter, the high temperature holding process will be described.

上記昇温工程にて加温した原料を、昇温後の温度、即ち８５０℃〜１２００℃で保持する。   The raw material heated in the temperature raising step is held at a temperature after the temperature raising, that is, 850 ° C to 1200 ° C.

保持時間は、昇温工程にて還元された原料が、十分にＶＯ２に酸化される時間であれば特に限定されず、例えば、１時間以上、好ましくは２〜６時間である。The holding time is not particularly limited as long as the raw material reduced in the temperature raising step is sufficiently oxidized to VO 2 , and is, for example, 1 hour or longer, preferably 2 to 6 hours.

高温保持工程は、その保持工程の少なくとも一部の期間、バナジウムが４価で安定となりやすい雰囲気下、例えば１×１０−７〜１×１０−１０ＭＰａの酸素分圧下で行われる。The high temperature holding step is performed under an atmosphere in which vanadium is tetravalent and stable, for example, under an oxygen partial pressure of 1 × 10 −7 to 1 × 10 −10 MPa for at least a part of the holding step.

高温保持工程の間、好ましくは、バナジウムが５価となるような酸化雰囲気下とならないように酸素濃度を制御する。このように制御することにより、バナジウムが５価となり、融点が低下することを防止することができる。   During the high temperature holding step, the oxygen concentration is preferably controlled so as not to be in an oxidizing atmosphere where vanadium becomes pentavalent. By controlling in this way, vanadium becomes pentavalent and it is possible to prevent the melting point from being lowered.

本発明の方法によれば、メジアン径が大きく、特に１０μｍ以上であり、高純度かつ吸熱量の大きい酸化バナジウムを大量に安定して合成することが可能になる。いかなる理論によっても拘束されないが、本発明の方法により、吸熱量の大きい酸化バナジウムが得られる理由は以下のように考えられる。まず。高温保持工程より強い還元雰囲気下で酸化バナジウムの原料を昇温することにより、バナジウムが還元されやすくなり５価のバナジウム量が少なくなる。つまり工程において、融点の低い（約８００℃）のＶ２Ｏ５が還元され、原料の酸化バナジウムの融点が高くなる（具体的には８００℃よりも高くなる）。融点が高くなることにより、高温保持工程において、酸化バナジウムの溶融による、雰囲気の不均一化が防止される。さらに、バナジウムは、酸素を失う反応（即ち、還元反応）よりも、酸素を獲得する反応（即ち、酸化反応）の方が進みやすいので、一旦目的の４価よりも還元し、それから４価まで酸化することにより、より均一なＶＯ２が得られると考えられる。According to the method of the present invention, it is possible to stably synthesize a large amount of vanadium oxide having a large median diameter, particularly 10 μm or more, and having a high purity and a large endothermic amount. Although not bound by any theory, the reason why vanadium oxide having a large endotherm can be obtained by the method of the present invention is considered as follows. First. By raising the temperature of the vanadium oxide raw material in a reducing atmosphere stronger than the high temperature holding step, vanadium is easily reduced and the amount of pentavalent vanadium is reduced. That is, in the process, V 2 O 5 having a low melting point (about 800 ° C.) is reduced, and the melting point of the raw material vanadium oxide becomes high (specifically, higher than 800 ° C.). By increasing the melting point, non-uniform atmosphere due to melting of vanadium oxide is prevented in the high temperature holding step. Furthermore, since vanadium is more likely to proceed with a reaction that acquires oxygen (that is, an oxidation reaction) than a reaction that loses oxygen (that is, a reduction reaction), the vanadium is once reduced rather than the target tetravalent, and then to the tetravalent. It is considered that more uniform VO 2 can be obtained by oxidation.

好ましい態様において、本発明の方法は、酸素濃度が制御された降温工程を含んでもよい。   In a preferred embodiment, the method of the present invention may include a temperature lowering step in which the oxygen concentration is controlled.

降温工程における８００℃での酸素分圧は、降温保持工程で得られたＶＯ２が酸化されないように、好ましくは、１×１０−１０ＭＰａ以下であり、より好ましくは１×１０−１１ＭＰａ以下である。また、再度還元されないように、８００℃での酸素分圧は、好ましくは１×１０−１３ＭＰａ以上、好ましくは１×１０−１２ＭＰａ以上である。The oxygen partial pressure at 800 ° C. in the temperature lowering step is preferably 1 × 10 −10 MPa or less, more preferably 1 × 10 −11 MPa or less so that VO 2 obtained in the temperature lowering holding step is not oxidized. It is. Moreover, the oxygen partial pressure at 800 ° C. is preferably 1 × 10 −13 MPa or more, preferably 1 × 10 −12 MPa or more so as not to be reduced again.

降温工程は、特に限定されないが、例えば、１〜１０時間、好ましくは３〜６時間で行われる。   Although a temperature fall process is not specifically limited, For example, it is performed for 1 to 10 hours, Preferably it is 3 to 6 hours.

・市販のＶＯ２
市販のＶＯ２（試料番号１）について、示差走査熱量測定（ＤＳＣ：Differential scanning calorimetry）を行い、吸熱量（潜熱量）を評価した。その結果、吸熱量は３５Ｊ／ｇであった。・ Commercially available VO 2
For commercial VO 2 (Sample No. 1), differential scanning calorimetry (DSC: Differential scanning calorimetry) was performed to evaluate the heat absorption amount (latent heat). As a result, the endothermic amount was 35 J / g.

・市販のＶＯ２からのＶＯ２の製造
出発原料として、上記の市販のＶＯ２を１２０ｇ秤量し、ポリポット容器に部分安定化ジルコニア（ＰＳＺ：Partial Stabilized Zirconia）ボール、純水、分散剤（サンノプコ製：ＳＮ５４６８）とともに入れて、１６時間湿式粉砕を行った。その後、混合スラリーを乾燥し、整粒して、図１に示す１００×１００×５０ｍｍ３（内容積９０×９０×４０ｍｍ３）のムライト製のさやに入れて蓋をして、水／水素／窒素雰囲気中で、熱処理した。- as a production starting material of the VO 2 from commercial VO 2, commercial VO 2 of the above 120g weighed, partially stabilized zirconia polyethylene pot container (PSZ: Partial Stabilized Zirconia) balls, pure water, dispersing agent (San Nopco Ltd. : SN5468) and wet milled for 16 hours. Thereafter, the mixed slurry was dried, sized, put into a mullite sheath of 100 × 100 × 50 mm 3 (internal volume 90 × 90 × 40 mm 3 ) shown in FIG. Heat treatment was performed in a nitrogen atmosphere.

熱処理は、表１に示すように、昇温工程における８００℃での酸素分圧、高温保持工程の温度および酸素分圧、ならびに降温工程における８００℃での酸素分圧を変更して、試料番号２〜１１（＊を付した番号は比較例である）について行った。なお、昇温工程における開始温度は、室温であり、所定の温度まで、３．５時間で昇温した。高温保持工程は、４時間であった。降温工程は、室温になるまで静置して冷却して、ＶＯ２粒子を得た。As shown in Table 1, the heat treatment was performed by changing the oxygen partial pressure at 800 ° C. in the temperature raising step, the temperature and oxygen partial pressure in the high temperature holding step, and the oxygen partial pressure at 800 ° C. in the temperature lowering step. 2 to 11 (numbers marked with * are comparative examples). The starting temperature in the temperature raising step was room temperature, and the temperature was raised to a predetermined temperature in 3.5 hours. The high temperature holding process was 4 hours. In the temperature lowering step, the mixture was allowed to stand until it reached room temperature and cooled to obtain VO 2 particles.

熱処理中、酸素分圧は、１５０℃以上の区間では水蒸気量と窒素量を一定とし、酸素分圧をモニターし、水素量を調節することにより制御した。酸素分圧は、炉内のガスをサンプリングしてジルコニア式酸素分圧計で測定することによりモニターした。   During the heat treatment, the oxygen partial pressure was controlled by adjusting the amount of hydrogen by monitoring the oxygen partial pressure while keeping the amount of water vapor and nitrogen constant in the section of 150 ° C. or higher. The oxygen partial pressure was monitored by sampling the gas in the furnace and measuring with a zirconia oxygen partial pressure meter.

Figure 0006256596
Figure 0006256596

・市販のＶＯ２からのＶ０．９９５Ｗ０．００５Ｏ２の製造
出発原料として、市販のＶＯ２に加え、酸化タングステン（ＷＯ３）を準備した。これを、ＶＯ２／ＷＯ３＝０．９９５／０．００５の混合比（モル比）で、出発原料を、総重量１２０ｇになるように秤量した。その他の工程は、上記ＶＯ２の製造と同様にして、試料番号１２〜１５について、熱処理を行い、Ｖ０．９９５Ｗ０．００５Ｏ２粒子を得た。処理条件は、下記表２に示す。· As V 0.995 W 0.005 production starting material of the O 2 from the commercial VO 2, in addition to commercial VO 2, was prepared tungsten oxide (WO 3). This was weighed so as to have a total weight of 120 g at a mixing ratio (molar ratio) of VO 2 / WO 3 = 0.995 / 0.005. In the other steps, the sample numbers 12 to 15 were heat-treated in the same manner as in the production of VO 2 to obtain V 0.995 W 0.005 O 2 particles. The processing conditions are shown in Table 2 below.

Figure 0006256596
Figure 0006256596

・特性試験
（粉末Ｘ線回折測定）
上記で作成した試料番号１〜１５について、粉末Ｘ線回折（ＸＲＤ：X-ray Diffraction）測定を行い、結晶性を評価した。試料番号２〜１５のＸＲＤ測定では、図２に示すように、さやの表面部、中央部、そして底面部から、試料をサンプリングして測定を行った。結果を下記表３に示す。また、試料番号１と試料番号２の粉末Ｘ線回折のチャートを図３に示す。・ Characteristic test (powder X-ray diffraction measurement)
About the sample numbers 1-15 created above, powder X-ray diffraction (XRD: X-ray Diffraction) measurement was performed and crystallinity was evaluated. In the XRD measurement of sample numbers 2 to 15, the samples were sampled from the surface portion, the center portion, and the bottom portion of the sheath as shown in FIG. The results are shown in Table 3 below. Further, a chart of powder X-ray diffraction of Sample No. 1 and Sample No. 2 is shown in FIG.

（示差走査熱量測定）
上記で作成した試料番号１〜１５について、示差走査熱量測定（ＤＳＣ：Differential scanning calorimetry）を行い、吸熱量（潜熱量）を評価した。結果を下記表３に併せて示す。(Differential scanning calorimetry)
About the sample numbers 1-15 created above, differential scanning calorimetry (DSC: Differential scanning calorimetry) was performed and the endothermic amount (latent heat amount) was evaluated. The results are also shown in Table 3 below.

（粒径測定）
上記で作成した試料番号１〜１５について、堀場製作所製レーザー回折/散乱式粒度分布測定装置 ＬＡ−９２０を用いて、粒径（メジアン径）を測定した。測定前に、適量の試料をヘキサメタリン酸Na水溶液に添加し、超音波洗浄機で１０分程度分散させ、その後測定を行った。これにより、粉体が凝集した試料では凝集をとき、また粒径の大きな粉体の沈殿などを抑制し、正確な粒度分布の測定が可能となる。また、念のため、電界放出形走査電子顕微鏡（ＦＥ−ＳＥＭ）で試料の粒径、粒形を確認し、レーザー回折/散乱式粒度分布測定装置で測定した粒径と１次粒径がほぼ同じであることを確認した。測定結果を下記表３に併せて示す。また、吸熱量とメジアン径の関連を調べるために、各試料についての結果を、吸熱量（Ｊ／ｇ）−メジアン径（μｍ）のグラフにプロットした。結果を図４に示す。(Particle size measurement)
About the sample numbers 1-15 created above, the particle size (median diameter) was measured using the laser diffraction / scattering type particle size distribution measuring apparatus LA-920 by Horiba. Prior to the measurement, an appropriate amount of the sample was added to the aqueous solution of sodium hexametaphosphate and dispersed with an ultrasonic cleaner for about 10 minutes, and then the measurement was performed. This makes it possible to accurately measure the particle size distribution by agglomerating a sample in which the powder is agglomerated and suppressing the precipitation of powder having a large particle size. As a precaution, the particle size and particle size of the sample were confirmed with a field emission scanning electron microscope (FE-SEM), and the particle size and primary particle size measured with a laser diffraction / scattering particle size distribution measuring device were almost the same. Confirmed the same. The measurement results are also shown in Table 3 below. Further, in order to investigate the relationship between the endothermic amount and the median diameter, the results for each sample were plotted on a graph of endothermic amount (J / g) -median diameter (μm). The results are shown in FIG.

Figure 0006256596
※表３において異相生成とはＸＲＤの回折強度から主成分であるＶＯ２に対して、他の酸化バナジウムが２０％以上存在していたことを示す。
Figure 0006256596
 * In Table 3, heterogeneous generation means that 20% or more of other vanadium oxide was present with respect to VO 2 as the main component from the diffraction intensity of XRD.

図３に示されるように、市販の試料番号１のＶＯ２と、加熱処理した試料番号２のＶＯ２間には、粉末Ｘ線回折測定で観測可能な結晶性の違いは見られなかった。また、試料番号３〜７、９および１１〜１５の結晶も単相であった。しかしながら、表３に示されるように、同じ単相であるＶＯ２であっても、吸熱量に違いがあることが確認された。As shown in FIG. 3, and VO 2 commercial sample No. 1, between VO 2 heat treated sample No. 2, the observable crystallinity by powder X-ray diffraction measurement difference was observed. The crystals of sample numbers 3-7, 9 and 11-15 were also single phase. However, as shown in Table 3, it was confirmed that there was a difference in the endothermic amount even with VO 2 which was the same single phase.

図４に示されるように、粒径（メジアン径）と吸熱量は強い相間を示し、粒径とが大きくなるに従い、吸熱量が向上することが確認された。このように、粒径は、吸熱量の指標として用いることができることが確認された。   As shown in FIG. 4, the particle size (median diameter) and the endothermic amount showed a strong phase, and it was confirmed that the endothermic amount was improved as the particle size increased. Thus, it was confirmed that the particle size can be used as an index of the endothermic amount.

また、これらの結果から、メジアン径が２μｍ以上である試料番号２〜７、９および１１のＶＯ２は、４０Ｊ／ｇ以上の吸熱量を有するのに対し、メジアン径が２μｍ未満である試料番号１は、吸熱量が３５Ｊ／ｇと小さかった。さらに、２μｍ以上のメジアン径を有するＷをドープした試料番号１２〜１５のＶＯ２は、Ｗをドープしたことにより吸熱量が低下するにもかかわらず、３０Ｊ／ｇ以上の吸熱量を有することが確認された。特に、メジアン径が１０μｍ以上である、試料番号２〜７は、６０Ｊ／ｇ以上と非常に優れた吸熱量を有することが確認された。また、このような、非常に優れた吸熱量を有するＶＯ２は、本発明の製造方法により製造できることが確認された。Further, from these results, VO 2 of sample numbers 2 to 7, 9 and 11 having a median diameter of 2 μm or more has an endotherm of 40 J / g or more, whereas the sample number having a median diameter of less than 2 μm. No. 1 had a small endotherm of 35 J / g. Further, VO 2 of sample numbers 12 to 15 doped with W having a median diameter of 2 μm or more may have an endotherm of 30 J / g or more, even though the endotherm is reduced by doping with W. confirmed. In particular, it was confirmed that Sample Nos. 2 to 7 having a median diameter of 10 μm or more have a very excellent endothermic amount of 60 J / g or more. It was also confirmed that VO 2 having such an excellent endothermic amount can be produced by the production method of the present invention.

本発明の酸化バナジウムは、高い潜熱を有するため、電子機器の冷却デバイス等、種々の用途に好適に利用できる。   Since the vanadium oxide of the present invention has high latent heat, it can be suitably used for various applications such as a cooling device for electronic equipment.

Claims (2)

メジアン径が２μｍ以上である、４価のバナジウム（Ｖ４＋）の酸化物を主成分とする酸化バナジウム粒子の製造方法であって：
（１）少なくとも１種の２価〜５価のバナジウムの酸化物、および所望により少なくとも１種のＭ（ここに、Ｍは、Ｗ、Ｔａ、ＭｏおよびＮｂから選択される）の酸化物を含む原料を、８５０℃以上１２００℃以下の温度にまで加熱する昇温工程；と
（２）昇温後の温度で保持する高温保持工程と
を含み、前記昇温工程において、８００℃での酸素分圧が、１×１０−１１ＭＰａ以下であり、前記高温保持工程の少なくとも一部期間において、酸素分圧が、１×１０−７〜１×１０−１０ＭＰａである、方法。 A method for producing vanadium oxide particles mainly composed of an oxide of tetravalent vanadium (V 4+ ) having a median diameter of 2 μm or more:
(1) including at least one divalent to pentavalent oxide of vanadium and optionally at least one oxide of M (where M is selected from W, Ta, Mo and Nb) raw materials, to heating process heated to a temperature below 1200 ° C. 850 ° C. or higher; and a high-temperature holding step of holding at a temperature after the (2) heating, in the Atsushi Nobori step, the oxygen content of at 800 ° C. pressure, not more than 1 × 10 -11 MPa, at least some period of the high temperature holding step, the oxygen partial pressure is 1 × 10 -7 ~1 × 10 -10 MPa, method. 前記原料がＶ２Ｏ５を含む、請求項１に記載の製造方法。 The material comprises V 2 O 5, The method according to claim 1.
JP2016511327A 2014-03-31 2014-12-19 Vanadium oxide and method for producing the same Active JP6256596B2 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP2014072533 2014-03-31
JP2014072533 2014-03-31
PCT/JP2014/083717 WO2015151355A1 (en) 2014-03-31 2014-12-19 Vanadium oxide and manufacturing method therefor

Publications (2)

Publication Number Publication Date
JPWO2015151355A1 JPWO2015151355A1 (en) 2017-04-13
JP6256596B2 true JP6256596B2 (en) 2018-01-10

Family

ID=54239712

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2016511327A Active JP6256596B2 (en) 2014-03-31 2014-12-19 Vanadium oxide and method for producing the same

Country Status (2)

Country Link
JP (1) JP6256596B2 (en)
WO (1) WO2015151355A1 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP7120665B2 (en) * 2019-01-09 2022-08-17 国立研究開発法人産業技術総合研究所 Powder material for sintering and latent heat type solid heat storage material using the same

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2726545B1 (en) * 1994-11-09 1997-01-31 Peintures Jefco VANADIUM DIOXIDE MICROPARTICLES, PROCESS FOR OBTAINING SUCH MICROPARTICLES AND THEIR USE, IN PARTICULAR FOR SURFACE COATINGS
JPH1167257A (en) * 1997-08-19 1999-03-09 Kashimakita Kyodo Hatsuden Kk Process for vanadium electrolyte
JP5625172B2 (en) * 2009-12-28 2014-11-19 東亞合成株式会社 Vanadium dioxide fine particles, production method thereof, and thermochromic film
JP5571026B2 (en) * 2011-03-29 2014-08-13 積水化学工業株式会社 Intermediate film for laminated glass, laminated glass, and method for producing laminated glass
JP2013071859A (en) * 2011-09-27 2013-04-22 Sekisui Chem Co Ltd Method for producing vanadium dioxide particle

Also Published As

Publication number Publication date
JPWO2015151355A1 (en) 2017-04-13
WO2015151355A1 (en) 2015-10-08

Similar Documents

Publication Publication Date Title
Matos et al. Effect of the sintering temperature on the properties of nanocrystalline Ca1− xSmxMnO3 (0≤ x≤ 0.4) powders
Kumar et al. Investigations on magnetic and electrical properties of Zn doped Fe2O3 nanoparticles and their correlation with local electronic structures
Kong et al. Aqueous chemical synthesis of Ln 2 Sn 2 O 7 pyrochlore‐structured ceramics
JP6351523B2 (en) Method for producing vanadium dioxide
Choi et al. Crystallization kinetics of lithium niobate glass: determination of the Johnson–Mehl–Avrami–Kolmogorov parameters
TWI616403B (en) Titanium oxide and method of producing the same
Jesus et al. Electric field-assisted ultrafast synthesis of nanopowders: a novel and cost-efficient approach
Fulle et al. Hydrothermal chemistry and growth of fergusonite-type RENbO4 (RE= La–Lu, Y) single crystals and new niobate hydroxides
Lopes et al. Crystallization kinetics of a barium–zinc borosilicate glass by a non-isothermal method
Bandyopadhyay et al. Microstructure and charge carrier dynamics in Dy substituted phase stabilized cubic Bi 2 O 3
Lee et al. A modified Vegard’s law for multisite occupancy of Ca in BaTiO3–CaTiO3 solid solutions
Tomaszewicz et al. Thermal and magnetic properties of new scheelite type Cd1− 3x□ xGd2xMoO4 ceramic materials
JP6256596B2 (en) Vanadium oxide and method for producing the same
Kuo et al. Growth kinetics of tetragonal and monoclinic ZrO2 crystallites in 3 mol% yttria partially stabilized ZrO2 (3Y-PSZ) precursor powder
Albetran et al. Effect of pressure on TiO2 crystallization kinetics using in‐situ high‐temperature synchrotron radiation diffraction
Wang et al. Phase stabilization in nitrogen-implanted nanocrystalline cubic zirconia
JP6197948B2 (en) Vanadium oxide and method for producing the same
Štefanić et al. Effect of Cu2+ ion incorporation on the phase development of ZrO2-type solid solutions during the thermal treatments
Acuña et al. Nanostructured terbium-doped ceria spheres: effect of dopants on their physical and chemical properties under reducing and oxidizing conditions
Costa et al. Thermodynamics of nanoscale lead titanate and barium titanate perovskites
Bulina et al. Mechanochemical Synthesis of SiO44–‐Substituted Hydroxyapatite, Part III–Thermal Stability
Matraszek et al. Phase Relationships in the Tricalcium Phosphate—Cerium Phosphate System. Thermal behavior of Phases Present in the System
Shutka et al. Preparation of dissimilarly structured ferrite compounds by sol-gel auto-combustion method
Jennet et al. From ferroelectric to relaxor behaviour in the Aurivillius-type Bi4− xBaxTi3− xNbxO12 (0≤ x≤ 1.4) solid solutions
JP6478223B2 (en) Yttrium-containing oxyapatite-type lanthanum / germanate ceramics

Legal Events

Date Code Title Description
A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20170808

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20170911

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20170919

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20171024

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20171107

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20171120

R150 Certificate of patent or registration of utility model

Ref document number: 6256596

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R150