WO2019044372A1

WO2019044372A1 - Method for producing zirconium phosphomolybdate fine particles

Info

Publication number: WO2019044372A1
Application number: PCT/JP2018/029096
Authority: WO
Inventors: 加藤　博和; 忠之伊左治; 淳一中島
Original assignee: 日産化学株式会社
Priority date: 2017-08-28
Filing date: 2018-08-02
Publication date: 2019-03-07
Also published as: TW201919991A

Abstract

The present invention comprises: a first step for mixing a water-soluble zirconium salt, a water-soluble molybdenum salt, and a water-soluble phosphate; a second (drying) step which is performed as necessary; and a third step for firing a mixture obtained after mixing at a temperature of 900-1200°C (exclusive of 1200°C), wherein the firing in the third step is performed while the molar ratio of a zirconium atom: molybdenum atom:phosphorus atom (Zr:Mo:P) in the mixture is 2:x:2-y (x≥1, 0≤y<5).

Description

Method for producing zirconium phosphomolybdate particles

The present invention relates to a method of producing zirconium phosphomolybdate particles.

With the spread of electronic devices, the demand for printed wiring boards, which are the main components of the electronic devices, is increasing. When the CTE of the semiconductor sealing material increases with respect to the coefficient of thermal expansion (CTE) of the substrate while circuit integration and layering progress, circuit destruction will occur. Therefore, in order to reduce the CTE of the sealing material, a technique is used in which a heat-resistant resin such as an epoxy resin constituting the material is filled with an inorganic material (such as amorphous fine particles) having a small CTE as a filler.

Not only as a filler of the above-mentioned sealing material, the technique which utilizes an amorphous | non-crystalline fine particle as a filler of underfilling is used. That is, a circuit mounted on a base material by wire bonding, flip chip bonding or the like is likely to be broken by a relatively small force because it is often fragile to external force or stress. Under the circumstances, it has been practiced to infiltrate a liquid curable resin (epoxy resin or the like) called an underfill between substrate parts to secure connection reliability. Here, since it is expected that thermal expansion and contraction of the resin may cause bonding breakage, an inorganic substance with small CTE (amorphous fine particles for the purpose of suppressing such thermal expansion and contraction of the resin Etc.) is used as a filler.

In the technology of filling such amorphous fine particles, the CTE of the sealing material and the material for forming the underfill (composite resin containing epoxy resin etc. as the main component) can be effectively reduced, further Improvement was desired.

Therefore, Zr ₂ MoP ₂ O ₁₂ , which is one of the formation phases of zirconium phosphomolybdate (sometimes referred to as zirconium molybdate phosphate), is known as a material having a high negative CTE, It is conceivable to use as a filler.

Regarding the above points, the molar ratio of ZrO ₂ , MoO ₃ and P ₂ O ₅ (ZrO ₂ : MoO ₃ : P ₂ O ₅ ) is mixed and fired at 2: 1 to 1.2: 1 to 1.2. It is disclosed that a sintered body of Zr ₂ MoP ₂ O ₁₂ is produced by a solid phase reaction method (see, for example, Patent Document 1). Further, by a solid phase reaction method of firing a mixture of oxide material of a predetermined allocation amount is disclosed that it is possible to synthesize a group of compounds containing Zr _₂ MoP ₂ O ₁₂ (e.g., see Non-Patent Document 1). In addition, it is disclosed that a Zr ₂ MoP ₂ O ₁₂ powder can be synthesized by a solid phase reaction method using ZrO ₂ , (NH ₄ ) H ₂ PO ₄ and a 20 mol% excess MoO ₃ as a starting material (for example, Non-Patent Document 2).

In addition, a compound group including Zr ₂ MoP ₂ O ₁₂ is disclosed, and a synthesis example by a solid phase reaction method using various oxides and (NH ₄ ) H ₂ PO ₄ as starting materials is described (for example, Patent Document 2). In Patent Document 2, a precipitate obtained by heating a mixed aqueous solution of oxychloride, nitrate and the like to 80 ° C. to 100 ° C. is calcined (liquid phase reaction method) to contain Zr ₂ MoP ₂ O ₁₂ It is stated that there is a possibility that compounds can be synthesized.

Chinese Patent No. 101891470 U.S. Pat. No. 5,919,720

However, in Patent Document 1, since the form of the obtained product is not a powder, it can not be used as a filler for reducing the CTE of the composite resin. Moreover, in the method using the solid phase reaction method such as Patent Document 1, Non-patent Document 1 and Non-Patent Document 2, there is a background that the highly pure Zr ₂ MoP ₂ O ₁₂ can not be produced.

Although the possibility of the liquid phase reaction method is suggested in Patent Document 2, no specific method has been studied. In particular, oxychlorides and nitrates are used as raw materials in Patent Document 2, but since there is a difference in water solubility among the raw materials, the precipitate obtained by heating the mixed aqueous solution to 80 ° C. to 100 ° C. There was a risk of deviation from the composition. In this case, highly pure Zr ₂ MoP ₂ O ₁₂ can not be obtained.

The present invention has been made in view of these circumstances, and it is desirable to use a synthetic method using a water-soluble raw material to make a highly pure Zr ₂ MoP ₂ O ₁₂ phase advantageous for reducing the CTE of a composite resin. It is an object of the present invention to provide the method of producing zirconium phosphomolybdate fine particles having

As a result of intensive studies to solve the above problems, the present inventors mixed water-soluble zirconium salt, water-soluble molybdenum salt and water-soluble phosphate, and the mixture after mixing was a zirconium atom: molybdenum atom: The Zr ₂ MoP ₂ O ₁₂ phase is obtained by calcination in a molar ratio of phosphorus atoms (Zr: Mo: P) of 2: x: 2-y (x ≧ 1, 0 ≦ y <0.5). It has been found that zirconium phosphomolybdate fine particles having high purity can be produced.

That is, the present invention relates to the method for producing zirconium phosphomolybdate fine particles described in any one of the following first to seventh aspects.

The first aspect includes a first step of mixing a water-soluble zirconium salt, a water-soluble molybdenum salt and a water-soluble phosphate, and a third step of firing the mixture after the mixing at a temperature of 900 ° C. or more and less than 1200 ° C. In the third step, the molar ratio of zirconium atom: molybdenum atom: phosphorus atom (Zr: Mo: P) in the mixture is 2: x: 2-y (x ≧ 1, 0 ≦ y <0. 5) The method for producing zirconium phosphomolybdate fine particles characterized in that the above-mentioned calcination is carried out.

According to a second aspect, in the first aspect, the crystallite diameter in the direction perpendicular to the (121) plane of the Zr ₂ MoP ₂ O ₁₂ phase, which is the generation phase of the zirconium phosphomolybdate fine particles, is less than 80 nm. It is a manufacturing method of the zirconium phosphomolybdate microparticles | fine-particles of description.

A third aspect is a method for producing zirconium phosphomolybdate fine particles according to the first aspect or the second aspect, wherein an ammonium salt of zirconium is used as the water-soluble zirconium salt.

A fourth aspect is the method for producing zirconium phosphomolybdate microparticles according to the first aspect or the second aspect, characterized in that an ammonium salt of molybdenum is used as the water-soluble molybdenum salt.

A fifth aspect is the method for producing zirconium phosphomolybdate microparticles according to the first aspect or the second aspect, characterized in that an ammonium salt of phosphoric acid is used as the water-soluble phosphate.

The sixth aspect is that, in the second step, the mixed aqueous solution containing the water-soluble zirconium salt, the water-soluble molybdenum salt and the water-soluble phosphate in the first step is dried in the second step. B. calcining at a temperature less than ° C. is a method for producing zirconium phosphomolybdate particles according to any one of the first to fifth aspects.

According to a seventh aspect, in the third step, an aqueous solution having a molar ratio (Zr: Mo: P) of 2: x: 2-y (x ≧ 1, 0 ≦ y <0.5) at 50 ° C. to 350 ° C. The first method of firing the mixture obtained by spray drying at less than 0 ° C., the molar ratio (Zr: Mo: P) is 2: x: 2-y (x ≧ 1, 0 ≦ y <0.5) And the second molar ratio (Zr: Mo: P) is 2: 2: x: 2-y (x ≧ 1, 0 ≦ y <). A third method of firing the mixture obtained by spray pyrolysis of an aqueous solution of 0.5) at a temperature of 350 ° C. or more and less than 900 ° C., any one of the first to sixth aspects It is a manufacturing method of the zirconium phosphomolybdate microparticles | fine-particles as described in one.

According to the present invention, using a synthesis method using a water-soluble raw material, zirconium phosphomolybdate fine particles having a high purity of Zr ₂ MoP ₂ O ₁₂ phase which is advantageous for reducing CTE of composite resin are manufactured. We can provide a way. The zirconium phosphomolybdate fine particles obtained by this production method can be suitably used as a filler for a semiconductor sealing material or underfilling.

The method for producing zirconium phosphomolybdate particles according to the present invention will be described. The following description shows one aspect of the present invention, and can be arbitrarily changed within the scope of the present invention.

The method for producing zirconium phosphomolybdate fine particles according to the present invention comprises the first step of mixing the water-soluble zirconium salt, the water-soluble molybdenum salt and the water-soluble phosphate, and the mixture after mixing at a temperature of 900 ° C. or more and less than 1200 ° C. In the third step, the molar ratio (Zr: Mo: P) of zirconium atom: molybdenum atom: phosphorus atom in the mixture is 2: x: 2-y (x ≧ 1, in the third step) Baking is performed in the range of 0 ≦ y <0.5).

Examples of the formation phase of zirconium phosphomolybdate include a Zr ₂ P ₂ O ₉ phase and a Zr ₂ MoP ₂ O ₁₂ phase. Both the Zr ₂ P ₂ O ₉ phase and the Zr ₂ MoP ₂ O ₁₂ phase have negative CTEs, but when comparing the _two , the Zr ₂ MoP ₂ O ₁₂ phase has a larger negative degree (smaller CTE) . Therefore, from the viewpoint of the effect of reducing the CTE of the composite resin by adding zirconium phosphomolybdate fine particles (CTE reduction effect), Zr ₂ P mixed in the Zr ₂ MoP ₂ O ₁₂ phase in the zirconium phosphomolybdate formation phase It is desirable that the proportion of ₂ O ₉ phase be small.

In this respect, according to the production method of the present invention, highly pure zirconium phosphomolybdate of the Zr ₂ MoP ₂ O ₁₂ phase can be obtained. In particular, the ratio of the X-ray diffraction peak intensity I _α of the (002) plane of the Zr ₂ P ₂ O ₉ phase to the X-ray diffraction peak intensity I _β belonging to the (121) plane of the Zr ₂ MoP ₂ O ₁₂ phase Zirconium phosphomolybdate having an I _α / I _β of less than 0.05, and even less than 0.01 can be obtained.

The smaller the value of the ratio I _α / I _β , the better the index to which the highly pure zirconium phosphomolybdate of the Zr ₂ MoP ₂ O ₁₂ phase is obtained. The zirconium phosphomolybdate obtained by the conventional manufacturing method is generally a mixture of the Zr ₂ P ₂ O ₉ phase and the Zr ₂ MoP ₂ O ₁₂ phase, but the phosphorus molybdenum obtained by the manufacturing method of the present invention According to the acid zirconium, it is possible to obtain zirconium phosphomolybdate having a high purity of the Zr ₂ MoP ₂ O ₁₂ phase in which the ratio I _α / I _β is less than 0.05.

Note that an example of an apparatus or method for calculating the ratio I _α / I _β is as in the embodiment. The diffraction peak is, for example, a database “PDF-2” of ICDD (international centre for differential data), and the Zr ₂ MoP ₂ O ₁₂ phase is a PDF No. 01-078-5687, Zr ₂ P ₂ O ₉ phase is PDF No. Attribution of the formation phase can be performed with reference to 01-070-0888.

First, the production method according to the present invention has a first step of mixing a water-soluble zirconium salt, a water-soluble molybdenum salt and a water-soluble phosphate. When preparing a mixed aqueous solution containing a water-soluble zirconium salt, a water-soluble molybdenum salt and a water-soluble phosphate, the solid material which is the above-mentioned salt can be dissolved in a predetermined solution as it is to obtain the mixed aqueous solution. It is preferable to mix the above aqueous solutions after the above-mentioned salts have been previously made into aqueous solutions. According to this, it becomes easy to adjust the molar ratio of the zirconium atom (Zr), the molybdenum atom (Mo) and the phosphorus atom (P) in the mixed aqueous solution, that is, the molar ratio at the time of charging.

The water-soluble zirconium salt is, for example, a zirconium salt which is dissolved in water at 25 ° C. in an amount of 1% by mass or more, and includes zirconium ammonium carbonate, zirconyl acetate, zirconyl chloride, and zirconyl nitrate. These can be used alone or as a mixture of two or more as long as there is no problem with compatibility. However, from the viewpoint of the stability of the mixed aqueous solution, it is preferable to use an ammonium salt (zirconium ammonium carbonate) alone. The ammonium salt also ensures the solubility in the mixed aqueous solution as compared to other strong acid salts.

The water-soluble molybdenum salt is, for example, a molybdenum salt which dissolves in water at 25 ° C. in an amount of 1% by mass or more, hexaammonium heptamolybdate and its hydrate, sodium molybdate and its hydrate, and potassium molybdate It can be mentioned. These can be used alone or as a mixture of two or more as long as there is no problem with compatibility.

Molybunden chloride is a compound with good water solubility, but it is unstable and may release hydrogen chloride gradually in the air to be decomposed. When a filler is used in an electronic device application, it is desirable that the filler does not contain a chloride or an alkali metal. From the viewpoint of containing no alkali element, hexaammonium heptamolybdate tetrahydrate is preferably used. be able to. In the case of ammonium salts, as in the case of zirconium, the solubility in the mixed aqueous solution is also secured compared to other strong acid salts.

The water-soluble phosphate is, for example, a phosphate dissolved in water at 25 ° C. in an amount of 1% by mass or more, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, triammonium phosphate, sodium dihydrogen phosphate, Disodium hydrogen phosphate and trisodium phosphate can be mentioned. These can be used alone or as a mixture of two or more as long as there is no problem with compatibility. As described above, since it is desirable that the filler used in the electronic device application does not contain an alkali metal, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, and triammonium phosphate can be preferably used. In the case of an ammonium salt, as in the case of zirconium and molybdenum, the solubility in a mixed aqueous solution is also secured as compared with other strong acid salts.

When preparing a mixed aqueous solution containing a water-soluble zirconium salt, a water-soluble molybdenum salt and a water-soluble phosphate, an oxycarboxylic acid such as citric acid or glycolic acid may be added. According to this, it is possible to suppress phase separation and gelation at the time of drying of the mixed aqueous solution, and maintain high uniformity.

Here, the mixed aqueous solution containing the water-soluble zirconium salt, the water-soluble molybdenum salt and the water-soluble phosphate in the first step can be dried in the second step. By carrying out such a second step, it becomes easy to ensure the mixing uniformity of the zirconium atom, the molybdenum atom and the phosphorus atom. Examples of the drying method include spray drying and lyophilization described below. Through such drying, it becomes easy to ensure the mixing uniformity of the zirconium atom, the molybdenum atom and the phosphorus atom together with the subsequent third step. In addition, the spray thermal decomposition mentioned later is also mentioned as a method of drying. In this case, the drying in the second step and the pre-baking are performed in the same step.

Moreover, the manufacturing method which concerns on this invention has the 3rd process of baking the mixture after mixing a water soluble zirconium salt, a water soluble molybdenum salt, and a water soluble phosphate at the temperature of 900 degreeC or more and less than 1200 degreeC. The mixture here includes the above-mentioned mixed aqueous solution and a dried product obtained by drying the mixed aqueous solution.

The temperature of the mixture in the air or in the oxidizing atmosphere is in the range of 900 ° C. to less than 1200 ° C., preferably in the range of 900 ° C. to less than 1150 ° C. When the temperature at the time of firing is above the above temperature, the Zr ₂ MoP ₂ O ₁₂ phase is thermally decomposed, and there is a possibility that the Zr ₂ P ₂ O ₉ phase may be changed with the sublimation of MoO ₃ . On the other hand, if the temperature at the time of firing is lower than the above temperature, there is a possibility that the water-soluble zirconium salt, the water-soluble molybdenum salt and the water-soluble phosphate may not sufficiently react with each other. In this case, Zr ₂ MoP ₂ O ₁₂ It becomes difficult to generate.

In addition, baking can also be performed in multiple times within said temperature range. For example, a second firing (main firing) may be performed after the first firing, which is the first firing. Each firing time is 0.5 to 20 hours, and may be 1 to 10 hours.

Moreover, it is preferable to perform pre-baking at a temperature lower than the sublimation temperature of MoO ₃ before firing (first firing when firing is performed a plurality of times). For example, by pre-baking in the atmosphere or in an oxidizing atmosphere at a temperature of 550 ° C. or more and less than 700 ° C., sublimation of MoO ₃ in the next firing step can be suppressed, whereby the produced phase of zirconium phosphomolybdate is produced. The ratio of the Zr ₂ P ₂ O ₉ phase mixed in the Zr ₂ MoP ₂ O ₁₂ phase can be reduced.

Furthermore, in the manufacturing method according to the present invention, in the third step, the molar ratio of zirconium atom: molybdenum atom: phosphorus atom in the mixture (Zr: Mo: P) is 2: x: 2-y (x ≧ 1). And 0 ≦ y <0.5). In other words, regardless of the molar ratio at the time of mixing the water-soluble zirconium salt, the water-soluble molybdenum salt and the water-soluble phosphate, the above molar ratio is realized at the time before firing. .

When there is an excess of phosphorus atoms with respect to the zirconium atom and the molybdenum atom, the Zr ₂ P ₂ O ₉ phase is likely to be formed in the produced phase of zirconium phosphomolybdate manufactured. On the other hand, when the phosphorus atom is insufficient with respect to the zirconium atom and the molybdenum atom, the ZrO ₂ phase and the Zr ₂ MoP ₂ O ₁₂ phase easily become a mixed phase.

When the zirconium atoms and molybdenum atoms relative to the phosphorus atom present in excess, the excess Mo component is sublimated as MoO _{_3,} since Zr _₂ MoP ₂ _{O 12} phase is obtained, the Zr _₂ MoP ₂ O ₁₂ phase high Pure zirconium phosphomolybdate can be obtained. On the other hand, when the molybdenum atom is insufficient with respect to the zirconium atom and the phosphorus atom, the Zr ₂ P ₂ O ₉ phase is easily generated.

The molar ratio of zirconium atom: molybdenum atom: phosphorus atom (Zr: Mo: P) in the mixture can be rephrased as the molar ratio of zirconium type atom: molybdenum type atom: phosphorus type atom. For example, some of the zirconium atoms may be substituted with hafnium atoms as long as the CTE reduction effect is obtained. In addition, a part of the molybdenum atom may be substituted by a tungsten atom in the range where the CTE reduction effect can be obtained.

In the third step, for example, drying obtained by spray-drying a mixed aqueous solution having a molar ratio (Zr: Mo: P) of 2: x: 2-y (x ≧ 1, 0 ≦ y <0.5) The first method of firing the substance (mixture) in the above temperature range is used. Spray drying can be carried out in the second step described above. For spray drying, a spray dryer capable of spraying and drying while maintaining a uniform mixing state in an aqueous solution, or a spray drying device according thereto can be used.

The temperature atmosphere at the time of drying with a spray dryer or a spray dryer according thereto is 50 ° C. or more and less than 350 ° C., and is equal to or less than the decomposition temperature of the water-soluble zirconium salt, water-soluble molybdenum salt and water-soluble phosphate used. Is preferred. The atmosphere for drying is not particularly limited, and may be in the air, in an oxidizing atmosphere, in a reducing atmosphere, or in an inert atmosphere.

In the third step, for example, it is obtained by freeze-drying an aqueous solution having a molar ratio (Zr: Mo: P) of 2: x: 2-y (x ≧ 1, 0 ≦ y <0.5). The second method of firing the dried product (mixture) in the above temperature range is used. Lyophilization can be performed in the second step described above. Lyophilization here includes vacuum lyophilization or freeze drying. As a refrigerant which can be used by freeze drying, a mixed medium of dry ice and methanol, liquid nitrogen and the like can be mentioned.

Furthermore, in the third step, for example, a mixed aqueous solution having a molar ratio (Zr: Mo: P) of 2: x: 2-y (x ≧ 1, 0 ≦ y <0.5) is sprayed at a predetermined temperature range The third method of thermal decomposition and firing is used. According to spray pyrolysis, the drying in the second step and the calcination are performed in the same step. According to spray pyrolysis, drying and pre-sintering can be simultaneously performed by atomizing a mixed aqueous solution in which water-soluble zirconium salt, water-soluble molybdenum salt and water-soluble phosphate are mixed, and spraying it in a heating furnace. . The temperature atmosphere in spray pyrolysis is, for example, 350 ° C. or more and less than 900 ° C. According to this, spray pyrolysis can be suitably performed.

Hereinafter, the present invention will be described by way of examples and comparative examples, but the present invention is not limited to these examples. In Examples and Comparative Examples, various evaluations were performed as follows.

<X-ray diffraction analysis>
X-ray source: Cu, voltage: 40 kV, current: 15 mA, step width: 0.02 °, scan rate: 10 ° / min, divergence angle slit (DS) using Rigaku X-ray diffractometer MiniFlex 600 0.625 °, scattering slit (SS); 8.0 mm, light receiving slit (S); OPEN, incident solar slit; 2.5 °, light receiving solar slit; measured at 2.5 °, X-ray diffraction data I got

<X-ray diffraction intensity>
The X-ray diffraction data of each sample was subjected to automatic processing for background processing and removal of Kβ radiation using analysis software PDXL-2, and the X-ray diffraction intensity was measured. Diffraction peak intensity I _α of (002) plane of Zr ₂ P ₂ O ₉ phase appearing near 2θ = 14.9 ° and strongest line of Zr ₂ MoP ₂ O ₁₂ phase appearing near 2θ = 19.8 ° The ratio I _α / I _β of the diffraction peak intensity I _β of the (121) plane was calculated.

<Calculation of crystallite diameter>
The X-ray diffraction data of each sample was subjected to automatic processing for background processing and removal of Kβ radiation using analysis software PDXL-2, and the crystallite diameter was calculated based on Scherrer's equation. The crystallite diameter of the Zr ₂ MoP ₂ O ₁₂ phase employed the crystallite diameter in the direction perpendicular to the (121) plane.

Preparation Example 1 Preparation of Molybdenum Salt Aqueous Solution 100 g of bulked hexaammonium heptamolybdate tetrahydrate was dissolved in 900 g of pure water to obtain a molybdenum salt aqueous solution.

Preparation Example 2 Preparation of Zirconium Salt Aqueous Solution A zirconium ammonium carbonate aqueous solution (manufactured by Nippon Light Metal Co., Ltd., product name; Baycoat 20, zirconium oxide concentration 19 to 20 mass%) was treated with pure water to a zirconium oxide concentration of 10 mass%. It was diluted to obtain an aqueous solution of zirconium salt.

Preparation Example 3 Preparation of Phosphate Aqueous Solution 100 g of diammonium hydrogen phosphate was dissolved in 900 g of pure water to obtain an aqueous phosphate solution.

Example 1
Citric acid in a mixed aqueous solution of 141.2 g (0.08 mol as Mo) of the aqueous solution of molybdenum salt obtained in Production Example 1 and 197.1 g (0.16 mol as Zr) of the aqueous solution of zirconium salt obtained in Production Example 2 42 g (0.2 mol) of monohydrate were added. Furthermore, 190.2 g (0.144 mol as P) of the phosphate aqueous solution obtained in Production Example 3 and 281 g of pure water were added to prepare a mixed aqueous solution. The specific gravity of the prepared mixed aqueous solution was 1.07, the pH was 6.6, and the electrical conductivity was 40.0 mS / cm.

This mixed aqueous solution was sent using a spray dryer (Palvis Mini Spray GB 210-A, manufactured by Yamato Scientific Co., Ltd.) at an inlet temperature of 210 ° C., a spray pressure of 0.15 MPa and an air volume of 0.55 m ³ / min. It dried on conditions of speed 400g / h, and obtained dry powder. The outlet temperature at this time was 90 ± 5 ° C. After 3.0 g of the obtained dry powder is put in a high purity alumina crucible and calcined at 600 ° C. for 4 hours in the atmosphere using an electric furnace, it is then calcined at 900 ° C. for 2 hours and then at 1050 ° C. for 2 hours. By firing, 1.2 g of powder was obtained.

When the obtained powder was identified by X-ray diffraction analysis, the generated phase consisted of a single phase of Zr ₂ MoP ₂ O ₁₂ , and the intensity ratio I _α / I _β of X-ray diffraction peaks was less than 0.01. In addition, the crystallite diameter calculated from the diffraction peak of the Zr ₂ MoP ₂ O ₁₂ phase (121) plane appearing near 2θ = 19.8 ° was 63 nm.

Example 2
A powder was obtained in the same manner as in Example 1 except that the main firing at 1050 ° C. was changed to 1150 ° C.

When the obtained powder was identified by X-ray diffraction analysis, the generated phase consisted of a single phase of Zr ₂ MoP ₂ O ₁₂ , and the intensity ratio I _α / I _β of X-ray diffraction peaks was less than 0.01. The crystallite diameter calculated from the diffraction peak of the Zr ₂ MoP ₂ O ₁₂ phase (121) surface appearing near 2θ = 19.8 ° was 64 nm.

[Example 3]
A powder was obtained in the same manner as in Example 1 except that the main firing at 1050 ° C. was not performed. When the obtained powder was identified by X-ray diffraction analysis, the generated phase consisted of a single phase of Zr ₂ MoP ₂ O ₁₂ , and the intensity ratio I _α / I _β of X-ray diffraction peaks was less than 0.01. The crystallite diameter calculated from the diffraction peak of the Zr ₂ MoP ₂ O ₁₂ phase (121) surface appearing near 2θ = 19.8 ° was 60 nm.

Example 4
Citric acid in a mixed aqueous solution of 141.2 g (0.08 mol as Mo) of the aqueous solution of molybdenum salt obtained in Production Example 1 and 197.1 g (0.16 mol as Zr) of the aqueous solution of zirconium salt obtained in Production Example 2 42 g (0.2 mol) of monohydrate were added. Furthermore, 179.6 g (0.136 mol as P) of the aqueous solution of phosphate obtained in Production Example 3 and 291.6 g of pure water were added to prepare a mixed aqueous solution. The specific gravity of the prepared mixed aqueous solution was 1.07, the pH was 6.8, and the electrical conductivity was 40.0 mS / cm.

The mixed aqueous solution was dried by a spray dryer in the same manner as in Example 1 to obtain a dry powder. 3.0 g of the obtained dry powder is put in a high purity alumina crucible and temporarily fired at 600 ° C. for 4 hours in the atmosphere using an electric furnace, and then main firing at 900 ° C. for 2 hours and 1150 ° C. for 2 hours As a result, 1.2 g of powder was obtained.

When the obtained powder was identified by X-ray diffraction analysis, the generated phase consisted of a single phase of Zr ₂ MoP ₂ O ₁₂ , and the intensity ratio I _α / I _β of X-ray diffraction peaks was less than 0.01. The crystallite diameter calculated from the diffraction peak of the Zr ₂ MoP ₂ O ₁₂ phase (121) surface appearing near 2θ = 19.8 ° was 71 nm.

[Example 5]
Citric acid in a mixed aqueous solution of 141.2 g (0.08 mol as Mo) of the aqueous solution of molybdenum salt obtained in Production Example 1 and 197.1 g (0.16 mol as Zr) of the aqueous solution of zirconium salt obtained in Production Example 2 42 g (0.2 mol) of monohydrate were added. Furthermore, 169.0 g (0.128 mol as P) of the aqueous phosphate solution obtained in Production Example 3 and 302.2 g of pure water were added to prepare a mixed aqueous solution. The specific gravity of the prepared mixed aqueous solution was 1.07, the pH was 6.8, and the electrical conductivity was 40.0 mS / cm.

The mixed aqueous solution was dried by a spray dryer as in Example 1 to obtain a dry powder. 3.0 g of the obtained dry powder is put in a high purity alumina crucible and temporarily fired at 600 ° C. for 4 hours in the atmosphere using an electric furnace, and then main firing at 900 ° C. for 2 hours and 1150 ° C. for 2 hours As a result, 1.2 g of powder was obtained.

When the obtained powder was identified by X-ray diffraction analysis, the generated phase consisted of a single phase of Zr ₂ MoP ₂ O ₁₂ , and the intensity ratio I _α / I _β of X-ray diffraction peaks was less than 0.01. The crystallite diameter calculated from the diffraction peak of the Zr ₂ MoP ₂ O ₁₂ phase (121) surface appearing near 2θ = 19.8 ° was 67 nm.

[Example 6]
A mixed aqueous solution of 141.2 g (0.08 mol as Mo) of the aqueous solution of molybdenum salt obtained in Production Example 1 and 197.1 g (0.16 mol as Zr) of the aqueous solution of zirconium salt obtained in Production Example 2 A mixed aqueous solution was prepared by adding 190.2 g (0.144 mol as P) of the aqueous phosphate solution obtained in Example 3 and 323 g of pure water. The specific gravity of the prepared mixed aqueous solution was 1.06, the pH was 8.7, and the electrical conductivity was 41.6 mS / cm.

The mixed aqueous solution was dried by a spray dryer in the same manner as in Example 1 to obtain a dry powder. 3.0 g of the obtained dry powder is put in a high purity alumina crucible and calcined at 600 ° C. for 4 hours in the atmosphere using an electric furnace, and then calcined at 900 ° C. for 2 hours and 1150 ° C. for 2 hours Thus, 1.5 g of powder was obtained.

[Example 7]
The powder was prepared in the same manner as in Example 1 except that the mixed aqueous solution was put into an eggplant flask and dried under reduced pressure at 10 Torr using a rotary evaporator instead of the method using a spray dryer. Obtained.

Comparative Example 1
A powder was obtained in the same manner as in Example 1 except that the firing conditions after temporary firing were changed to 800 ° C. for 2 hours. When the obtained powder was identified by X-ray diffraction analysis, it was found that it was a mixed phase of the intermediate products ZrP ₂ O ₇ and Zr ₂ MoP ₂ O ₁₂ and the firing was insufficient.

Comparative Example 2
A powder was obtained in the same manner as in Example 1 except that the main firing at 1050 ° C. was changed to 1200 ° C. The obtained powder was identified by X-ray diffraction analysis, and thermal decomposition proceeded completely to be almost single phase of Zr ₂ P ₂ O ₉ . In addition, MoO ₃ generated during thermal decomposition is not detected by X-ray diffractometry because it is sublimated and released out of the system.

Comparative Example 3
Citric acid in a mixed aqueous solution of 141.2 g (0.08 mol as Mo) of the aqueous solution of molybdenum salt obtained in Production Example 1 and 197.1 g (0.16 mol as Zr) of the aqueous solution of zirconium salt obtained in Production Example 2 42 g (0.2 mol) of monohydrate were added. Furthermore, 200.7 g (0.152 mol as P) of the aqueous solution of phosphate obtained in Production Example 3 and 270.5 g of pure water were added to prepare a mixed aqueous solution. The specific gravity of the prepared mixed aqueous solution was 1.07, the pH was 7.1, and the electrical conductivity was 40.4 mS / cm.

When the obtained powder was identified by X-ray diffraction analysis, the product phase is a mixed phase of Zr ₂ P ₂ O ₉ and Zr ₂ MoP ₂ O ₁₂ , and the intensity ratio I _α / I _β of X-ray diffraction peaks is 0. It was 15.

Comparative Example 4
Citric acid in a mixed aqueous solution of 141.2 g (0.08 mol as Mo) of the aqueous solution of molybdenum salt obtained in Production Example 1 and 197.1 g (0.16 mol as Zr) of the aqueous solution of zirconium salt obtained in Production Example 2 42 g (0.2 mol) of monohydrate were added. Furthermore, 158.4 g (0.120 mol as P) of the aqueous phosphate solution obtained in Production Example 3 and 312.8 g of pure water were added to prepare a mixed aqueous solution. The specific gravity of the prepared mixed aqueous solution was 1.07, the pH was 6.3, and the electrical conductivity was 39.8 mS / cm.

When the obtained powder was identified by X-ray diffraction analysis, no diffraction of Zr ₂ P ₂ O ₉ was observed, but the formed phase was a mixed phase of ZrO ₂ and Zr ₂ MoP ₂ O ₁₂ .

Comparative Example 5
19.11 g (0.08 mol as Zr) of powdered ammonium zirconium carbonate (containing 51.58% as ZrO ₂ ) and 7.06 g (0.04 mol as Mo) of powdered ammonium heptamolybdate tetrahydrate And 9.51 g of diammonium hydrogen phosphate (0.072 mol as P) were ground and mixed for 30 minutes using an agate mortar to prepare a mixed powder. Into a high purity alumina crucible, 4.0 g of the prepared mixed powder is put, and after calcining at 600 ° C. for 4 hours in the atmosphere using an electric furnace, it is bluish by baking at 900 ° C. for 2 hours 2.2 g of white powder was obtained. When the obtained powder was identified by X-ray diffraction analysis, the product phase was a mixed phase of ZrP ₂ O ₇ and Zr ₂ MoP ₂ O ₁₂ .

Comparative Example 6
A powder was obtained in the same manner as in Comparative Example 5 except that baking was performed at 1050 ° C. for 2 hours after baking at 900 ° C. When the obtained powder was identified by X-ray diffraction analysis, the product phase was a mixed phase of ZrP ₂ O ₇ and Zr ₂ MoP ₂ O ₁₂ .

The above results are summarized in Table 1. In the table, in the examples and comparative examples in which the firing was performed twice, the first firing is represented simply as "firing" and the second firing is represented as "main firing".

As described above, according to Examples 1 to 7, phosphorus having a high purity of Zr ₂ MoP ₂ O ₁₂ phase which is advantageous for reducing the CTE of the composite resin by using a synthesis method using a water-soluble raw material It was confirmed that zirconium molybdate fine particles can be produced. The obtained zirconium phosphomolybdate was a highly pure Zr ₂ MoP ₂ O ₁₂ phase in which the ratio I _α / I _β was less than 0.05 in any of Examples 1 to 7.

In particular, according to Examples 1 to 7, it was confirmed that zirconium phosphomolybdate fine particles having a crystallite diameter of less than 80 nm can be obtained. The particle size is small and can be densely packed into a composite resin. Therefore, according to the zirconium phosphomolybdate fine particles produced in Examples 1 to 7, a high CTE reduction effect can be expected by using it as a filler of a composite resin.

However, in Comparative Examples 1 to 2 where the firing temperature is not within the range of the present invention, Comparative Examples 3 to 4 where the molar ratio of zirconium atom: molybdenum atom: phosphorus atom is not within the range of the present invention, and liquid phase reaction methods such as the present invention It was confirmed that the zirconium phosphomolybdate fine particles as in Examples 1 to 7 can not be obtained in Comparative Examples 5 to 6 in which no such substance is obtained.

The method for producing zirconium phosphomolybdate fine particles of the present invention is a phosphorus having a high purity of Zr ₂ MoP ₂ O ₁₂ phase which is advantageous for reducing CTE of composite resin by using a synthesis method using a water-soluble raw material. Zirconium molybdate fine particles can be obtained. Therefore, it can be suitably used as a filler for reducing CTE, for example, in applications such as semiconductor sealing materials and underfills.

Claims

Including a first step of mixing the water-soluble zirconium salt, the water-soluble molybdenum salt and the water-soluble phosphate, and a third step of firing the mixture after the mixing at a temperature of 900 ° C to less than 1200 ° C;
In the third step, the molar ratio of zirconium atom: molybdenum atom: phosphorus atom (Zr: Mo: P) in the mixture is 2: 2: x: 2-y (x ≧ 1, 0 ≦ y <0.5). A method for producing zirconium phosphomolybdate fine particles, characterized in that the firing is performed in a certain place.
The phosphomolybdic acid according to claim 1, wherein the crystallite diameter in the direction perpendicular to the (121) plane of the Zr 2 MoP 2 O 12 phase, which is the formation phase of the zirconium phosphomolybdate fine particles, is less than 80 nm. Method of producing zirconium fine particles.
The ammonium salt of zirconium is used as said water soluble zirconium salt. The manufacturing method of the zirconium phosphomolybdate microparticles | fine-particles of Claim 1 or 2 characterized by these.
The ammonium salt of molybdenum is used as said water-soluble molybdenum salt. The manufacturing method of the phosphomolybdate zirconium microparticles | fine-particles of Claim 1 or 2 characterized by these.
The ammonium salt of phosphoric acid is used as said water-soluble phosphate, The manufacturing method of the phosphomolybdate zirconium microparticles | fine-particles of Claim 1 or 2 characterized by these.
Drying the mixed aqueous solution containing the water-soluble zirconium salt, the water-soluble molybdenum salt and the water-soluble phosphate in the first step in the second step, and in the third step the mixture at a temperature of 900 ° C to less than 1200 ° C The method for producing zirconium phosphomolybdate particles according to any one of claims 1 to 5, comprising: baking.
In the third step,
The aqueous solution having the molar ratio (Zr: Mo: P) of 2: x: 2-y (x ≧ 1, 0 ≦ y <0.5) is spray-dried at 50 ° C. or more and less than 350 ° C. A first method of firing the mixture,
A second baking is performed on the mixture obtained by lyophilizing an aqueous solution having the molar ratio (Zr: Mo: P) of 2: x: 2-y (x ≧ 1, 0 ≦ y <0.5). Or spray pyrolysis of an aqueous solution having the molar ratio (Zr: Mo: P) of 2: x: 2-y (x ≧ 1, 0 ≦ y <0.5) at 350 ° C. to less than 900 ° C. The method for producing zirconium phosphomolybdate microparticles according to any one of claims 1 to 6, wherein the third method of firing the obtained mixture is used.