JP5438956B2 - Method for producing particles having coating layer - Google Patents
Method for producing particles having coating layer Download PDFInfo
- Publication number
- JP5438956B2 JP5438956B2 JP2008317614A JP2008317614A JP5438956B2 JP 5438956 B2 JP5438956 B2 JP 5438956B2 JP 2008317614 A JP2008317614 A JP 2008317614A JP 2008317614 A JP2008317614 A JP 2008317614A JP 5438956 B2 JP5438956 B2 JP 5438956B2
- Authority
- JP
- Japan
- Prior art keywords
- particles
- mother liquor
- coating layer
- core material
- strong dispersion
- 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.)
- Expired - Fee Related
Links
Description
本発明は、芯材粒子の表面が被覆層で被覆された粒子を製造する方法に関する。 The present invention relates to a method for producing particles in which the surface of core particles is coated with a coating layer.
本出願人は先に、芯材粒子の表面に酸化錫層が形成された導電性粉末及びその製造方法を提案した（特許文献１参照）。同文献で提案されている製造方法は、以下の工程を含むものである。先ず芯材を水中に分散させたスラリーが仕込まれた反応槽中に水溶性錫化合物を添加後、酸又はアルカリを用いて中和反応を行う。これによって、芯材の表面に酸化錫水和物からなる被覆層が形成された導電性粉末前駆体を、反応槽中に生成させる。この前駆体を含むスラリーの少なくとも一部を、中和の際又は中和の後に、反応槽とは別に設置した強分散装置において強分散処理し、強分散処理した液を反応槽のスラリー中に戻す。その後、スラリー中の前駆体を洗浄・乾燥した後、非酸化性雰囲気中２００〜１２００℃で焼成する。これによって目的とする酸化錫層が形成された導電性粉末が得られる。 The present applicant has previously proposed a conductive powder having a tin oxide layer formed on the surface of core material particles and a method for producing the same (see Patent Document 1). The manufacturing method proposed in this document includes the following steps. First, a water-soluble tin compound is added to a reaction tank in which a slurry in which a core material is dispersed in water is added, and then a neutralization reaction is performed using an acid or an alkali. Thereby, the conductive powder precursor in which the coating layer made of tin oxide hydrate is formed on the surface of the core material is generated in the reaction vessel. At least a part of the slurry containing the precursor is subjected to strong dispersion treatment in a strong dispersion apparatus installed separately from the reaction tank during or after neutralization, and the strongly dispersed liquid is put into the slurry of the reaction tank. return. Thereafter, the precursor in the slurry is washed and dried, and then fired at 200 to 1200 ° C. in a non-oxidizing atmosphere. As a result, a conductive powder in which a target tin oxide layer is formed is obtained.
上述の方法で製造された導電性粉末は、導電性が高く、また分散性に優れ、良好な白色度を有するものとなる。したがって、この導電性粉末を、例えば紙、プラスチック、ゴム、樹脂、塗料等に配合することで、これらの材料からなる製品に導電性を容易に付与することができる。しかも、これらの材料の色が損なわれることもない。 The conductive powder produced by the above method has high conductivity, excellent dispersibility, and good whiteness. Therefore, by adding this conductive powder to, for example, paper, plastic, rubber, resin, paint, etc., conductivity can be easily imparted to products made of these materials. Moreover, the color of these materials is not impaired.
しかし、この種の導電性粉末に対する要求は日増しに高くなっており、更に分散性が高く、且つ一層均質なものが望まれている。 However, the demand for this type of conductive powder is increasing day by day, and further higher dispersibility and a more homogeneous powder are desired.
従って本発明の目的は、前述した従来技術の粒子よりも更に性能が向上した被覆層を有する粒子を製造し得る方法を提供することにある。 Accordingly, an object of the present invention is to provide a method capable of producing particles having a coating layer whose performance is further improved as compared with the particles of the prior art described above.
本発明は、芯材粒子が媒体に分散してなる母液を循環させつつ、循環経路の一部に設けられた強分散装置に被覆層形成用の反応物を供給し、
該強分散装置において該母液を強分散させた状態下に該母液と該反応物とを反応させて、該芯材粒子の表面に被覆層を形成する、被覆層を有する粒子の製造方法であって、
前記芯材粒子は、そのＤ ５０ が０．０１〜１００μｍであり、
前記被覆層形成用の反応物が酸又はアルカリであり、
前記強分散装置がホモジナイザであり、
前記強分散装置の容積Ｖ２が１０〜５００ｃｍ ３ であり、
前記強分散装置に供給される前記反応物の速度Ｓ３と該強分散装置に流入する前記母液の流速Ｓ１との比Ｓ３／Ｓ１が０．０１〜０．０５であり、
前記被覆層を有する粒子が、Ｄ ５０ ／Ｄ ９０ の値が０．５〜１である導電性粒子である、被覆層を有する粒子の製造方法を提供するものである。
The present invention circulates a mother liquor in which core particles are dispersed in a medium, and supplies a reactant for forming a coating layer to a strong dispersion device provided in a part of the circulation path.
Reacting the mother liquor and the reaction under conditions where the mother liquor obtained by the strongly dispersed in said strong dispersion device, it forms a coating layer on the surface of the core material particles, in the manufacturing method of the particles having a coating layer There,
The core particles, the D 50 is 0.01 to 100 [mu] m,
The reaction product for forming the coating layer is an acid or an alkali,
The strong dispersion device is a homogenizer;
The volume V2 of the strong dispersion device is 10 to 500 cm 3 ,
The ratio S3 / S1 of the reactant flow rate S3 supplied to the strong dispersion device and the flow rate S1 of the mother liquor flowing into the strong dispersion device is 0.01 to 0.05,
It said particles having a coating layer, the value of D 50 / D 90 is electrically conductive particles is 0.5 to 1, there is provided a method for producing particles having a coating layer.
本発明によれば、芯材の表面に被覆層が均一に形成された粒子を高い量産性で容易に製造することができる。本発明の方法によって製造された粒子は、凝集の程度が低く、分散性の高いものとなる。 ADVANTAGE OF THE INVENTION According to this invention, the particle | grains in which the coating layer was uniformly formed on the surface of the core material can be easily manufactured with high mass productivity. The particles produced by the method of the present invention have a low degree of aggregation and high dispersibility.
以下本発明を、その好ましい実施形態に基づき図面を参照しながら説明する。本発明の一実施形態として、以下の説明においては、水酸化錫で被覆された粒子を製造する方法を例に挙げる。この粒子は、その後の工程で焼成されて、最終目的物である酸化錫で被覆された導電性粒子となる。図１には、該粒子の製造に好適に用いられる製造装置の一例の模式図が示されている。 The present invention will be described below based on preferred embodiments with reference to the drawings. As an embodiment of the present invention, in the following description, a method for producing particles coated with tin hydroxide will be described as an example. The particles are fired in a subsequent process to become conductive particles coated with tin oxide, which is the final object. FIG. 1 shows a schematic diagram of an example of a production apparatus suitably used for production of the particles.
図１に示す製造装置１０は、母液槽１１、母液槽１１の底部から延びる第１循環配管１２、第１循環配管１２の出口側に接続された強分散装置１３、強分散装置１３の出口側に接続され、且つ母液槽１１へ帰還する第２循環配管１４とを備えている。これらの部材によって、装置１０には循環経路が形成される。第１循環配管１２の途中には第１ポンプ１５が設置されている。また第２循環配管１４の途中には第２ポンプ１６が設置されている。 1 includes a mother liquor tank 11, a first circulation pipe 12 extending from the bottom of the mother liquor tank 11, a strong dispersion apparatus 13 connected to the outlet side of the first circulation pipe 12, and an outlet side of the strong dispersion apparatus 13. And a second circulation pipe 14 that returns to the mother liquor tank 11. These members form a circulation path in the device 10. A first pump 15 is installed in the middle of the first circulation pipe 12. A second pump 16 is installed in the middle of the second circulation pipe 14.
母液槽１１内には攪拌翼１１ａが設置されている。攪拌翼１１ａはシャフト１１ｂを介して槽外に設置されたモータ１１ｃに接続している。攪拌翼１１ａは、モータ１１ｃを駆動源として一定方向に回転するようになっている。 A stirring blade 11 a is installed in the mother liquor tank 11. The stirring blade 11a is connected to a motor 11c installed outside the tank through a shaft 11b. The stirring blade 11a rotates in a fixed direction using the motor 11c as a drive source.
強分散装置１３内には、攪拌部１３ａが設置されている。攪拌部１３ａはシャフト１３ｂを介してモータ１３ｃに接続している。攪拌部１３ａは、モータ１３ｃを駆動源として一定方向に回転するようになっている。更に強分散装置１３には、被覆層形成用の反応物を供給する供給部１３ｄが設けられている。強分散装置１３としてはその容積が、母液層１１の容積よりも十分に小さいものが用いられる。 A stirring unit 13 a is installed in the strong dispersion device 13. The stirring unit 13a is connected to a motor 13c through a shaft 13b. The stirring unit 13a rotates in a fixed direction using the motor 13c as a drive source. Further, the strong dispersion device 13 is provided with a supply unit 13d for supplying a reactant for forming the coating layer. As the strong dispersion device 13, a device whose volume is sufficiently smaller than the volume of the mother liquor layer 11 is used.
以上の装置１０を用いた粒子の製造方法について説明すると、先ず母液槽１１内に母液２０を充填する。母液２０は、芯材粒子が媒体に分散してなるものである。媒体としては、芯材粒子の種類や、被覆層を形成するときの反応等に応じて適切な液体が選択される。一般的には水が用いられる。 The particle production method using the above apparatus 10 will be described. First, the mother liquor tank 11 is filled with the mother liquor 20. The mother liquor 20 is obtained by dispersing core material particles in a medium. As the medium, an appropriate liquid is selected according to the kind of the core material particles, the reaction when forming the coating layer, and the like. In general, water is used.
芯材粒子としては、その表面に水酸化錫の被覆層を形成することが可能なものが用いられる。芯材粒子の材質としては、例えば、二酸化チタン、硫酸バリウム、アルミナ、二酸化珪素、雲母、タルク、ホウ酸アルミニウム、酸化亜鉛（ＺｎＯ）及びチタン酸アルカリ金属塩等が挙げられる。これらの芯材粒子の形状は、目的とする被覆粒子の具体的な用途に応じて適切な形状が選択される。例えば球場、フレーク状、針状等の形状のものが用いられる。 As the core material particles, those capable of forming a tin hydroxide coating layer on the surface thereof are used. Examples of the material of the core particles include titanium dioxide, barium sulfate, alumina, silicon dioxide, mica, talc, aluminum borate, zinc oxide (ZnO), and alkali metal titanate. As the shape of these core particles, an appropriate shape is selected according to the specific application of the target coated particles. For example, a ball field, flake shape, needle shape, or the like is used.
芯材粒子の粒径は、最終目的物である酸化錫被覆導電性粒子の具体的な用途に応じて適切な値が選択される。例えば芯材粒子はその平均粒径Ｄ50が好ましくは０．０１〜１００μｍ、更に好ましくは０．１〜１０μｍである。芯材の平均粒径がこの範囲内にあれば、最終目的物である酸化錫被覆導電性粒子が樹脂等中に分散し易いものとなるので好ましい。本明細書において平均粒径Ｄ50とは、レーザー回折散乱法で求められる体積平均粒径をいう。 As the particle diameter of the core material particles, an appropriate value is selected according to the specific application of the tin oxide-coated conductive particles that are the final target. For example the core material particles is an average particle diameter D 50 of preferably 0.01 to 100 [mu] m, more preferably from 0.1 to 10 [mu] m. If the average particle diameter of the core is within this range, the tin oxide-coated conductive particles that are the final target are easily dispersed in a resin or the like, which is preferable. In this specification, the average particle diameter D 50 refers to a volume average particle diameter determined by a laser diffraction scattering method.
母液２０における媒体と芯材粒子との配合比率は、媒体１リットルに対して芯材粒子が６０〜１５０ｇ、特に８０〜１２０ｇであることが好ましい。両者の配合比率がこの範囲内にあると、芯材粒子の表面に水酸化錫の均一な被覆層が容易に形成されるからである。 The mixing ratio of the medium and the core material particles in the mother liquor 20 is preferably 60 to 150 g, particularly 80 to 120 g, of the core material particles with respect to 1 liter of the medium. This is because a uniform coating layer of tin hydroxide is easily formed on the surface of the core particles when the blending ratio of the two is within this range.
母液２０中には、芯材粒子に加えて水溶性錫化合物が配合されていることが好ましい。水溶性錫化合物は、被覆層である水酸化錫の層を形成するための反応物の一つである。水溶性錫化合物としては、芯材粒子の表面に水酸化錫の被覆層を形成し得るものが用いられる。そのような水溶性錫化合物としては、錫酸ナトリウム及び四塩化錫等が挙げられる。これらの水溶液錫化合物は水への溶解が容易なので好適に用いられる。 The mother liquor 20 preferably contains a water-soluble tin compound in addition to the core particles. The water-soluble tin compound is one of the reactants for forming a tin hydroxide layer that is a coating layer. As the water-soluble tin compound, those capable of forming a tin hydroxide coating layer on the surface of the core particles are used. Examples of such water-soluble tin compounds include sodium stannate and tin tetrachloride. These aqueous tin compounds are preferably used because they are easily dissolved in water.
母液２０中における媒体と水溶性錫化合物との配合比率は、媒体の重量に対する水溶性錫化合物中のＳｎ量が１〜２０重量％、特に３〜１０重量％であることが好ましい。両者の配合比率がこの範囲内にあると、芯材粒子の表面に水酸化錫の均一な被覆層が容易に形成されるからである。 The mixing ratio of the medium and the water-soluble tin compound in the mother liquor 20 is preferably such that the Sn amount in the water-soluble tin compound is 1 to 20% by weight, particularly 3 to 10% by weight, based on the weight of the medium. This is because a uniform coating layer of tin hydroxide is easily formed on the surface of the core particles when the blending ratio of the two is within this range.
母液槽１１内に所定量の母液２０が充填されたら、母液槽１１の攪拌翼１１ａの回転を開始して芯材粒子の沈降を防止し、母液２０を均質なものとする。次いで、第１ポンプ１５、強分散装置１３及び第２ポンプ１６を起動して、装置１０に形成された循環経路内に母液２０を通し、これを循環させる。 When a predetermined amount of the mother liquor 20 is filled in the mother liquor tank 11, the rotation of the stirring blade 11a of the mother liquor tank 11 is started to prevent sedimentation of the core particles, and the mother liquor 20 is made homogeneous. Next, the first pump 15, the strong dispersion device 13, and the second pump 16 are activated to pass the mother liquor 20 through the circulation path formed in the device 10 and circulate it.
循環経路内での母液２０の循環が安定したら、強分散装置１３の供給部１３ｄを通じて強分散装置１３内に、被覆層形成用の反応物を供給する。強分散装置１３内に供給する反応物として、本実施形態においては酸又はアルカリを用いる。酸及びアルカリは、母液２０に配合されている水溶性錫化合物を中和させて、芯材粒子の表面に水酸化錫の層を生成させる。 When the circulation of the mother liquor 20 in the circulation path is stabilized, the reactant for forming the coating layer is supplied into the strong dispersion device 13 through the supply unit 13d of the strong dispersion device 13. In the present embodiment, acid or alkali is used as a reactant to be supplied into the strong dispersion device 13. The acid and alkali neutralize the water-soluble tin compound blended in the mother liquor 20 to form a tin hydroxide layer on the surface of the core material particles.
酸又はアルカリによる水溶性錫化合物の中和反応は、非常に迅速に進行する。したがって、例えば非常に大容量の反応槽を用い、これに芯材粒子が分散した水溶性錫化合物の水溶液を充填しておき、その中に酸又はアルカリを添加して中和反応を起こさせようとすると、反応槽内を攪拌したとしても、酸又はアルカリを添加した部分において中和反応が局所的に生じてしまい、芯材粒子の表面に水酸化錫の被覆層を均一に形成することができない。また、水酸化錫の被覆層は軟質のものなので、中和反応の最中に被覆層どうしが付着して粒子の凝集が起こってしまう。これに対して本実施形態によれば、強分散装置１３は、上述のとおり母液槽１１よりもはるかに小容量のものであり、しかも母液２０を高速攪拌するものであるから、局所的な中和反応が生ずることが防止され、芯材粒子の表面に水酸化錫の被覆層を均一に形成することができる。また、芯材粒子が極めて分散した状態になるので、粒子の凝集を効果的に防止することができる。このことは、特に芯材粒子として凝集の起こりやすい粒子である小粒径の粒子（例えば粒径が０．０１〜１μｍのもの）を用いた場合に有効である。しかも母液２０は、循環経路内を循環しているので、強分散装置１３に供給する酸又はアルカリの量及び／又は濃度を低くして中和反応を徐々に行うことができる。それによっても芯材粒子の表面に水酸化錫の被覆層を均一に形成することができ、また粒子の凝集を防止できる。 The neutralization reaction of the water-soluble tin compound with acid or alkali proceeds very rapidly. Therefore, for example, a very large capacity reaction tank is used, and this is filled with an aqueous solution of a water-soluble tin compound in which core particles are dispersed, and an acid or alkali is added therein to cause a neutralization reaction. Then, even if the inside of the reaction vessel is stirred, a neutralization reaction locally occurs in the portion where the acid or alkali is added, and a tin hydroxide coating layer can be uniformly formed on the surface of the core material particles. Can not. Further, since the tin hydroxide coating layer is soft, the coating layers adhere to each other during the neutralization reaction, and particles are aggregated. On the other hand, according to the present embodiment, the strong dispersion device 13 has a much smaller volume than the mother liquor tank 11 as described above, and stirs the mother liquor 20 at a high speed. A sum reaction is prevented from occurring, and a tin hydroxide coating layer can be uniformly formed on the surface of the core particles. In addition, since the core particles are extremely dispersed, the aggregation of the particles can be effectively prevented. This is particularly effective when small-diameter particles (for example, particles having a particle diameter of 0.01 to 1 μm), which are particles that tend to aggregate, are used as the core material particles. Moreover, since the mother liquor 20 circulates in the circulation path, the amount and / or concentration of the acid or alkali supplied to the strong dispersion device 13 can be lowered and the neutralization reaction can be performed gradually. This also makes it possible to uniformly form a tin hydroxide coating layer on the surface of the core particles, and to prevent aggregation of the particles.
背景技術の項で述べた本出願人の先の出願に係る特開２００５−１０８７３４号公報においては、本実施形態と異なり、母液槽に芯材粒子、水溶性錫化合物、及び酸又はアルカリを添加して中和反応を起こさせ、中和後の液を強分散装置で分散させている。この中和反応は、上述のとおり非常に迅速に進行するので、強分散装置においては中和反応は実質的に起こらない。したがって、強分散装置で液を分散させたとしても、それに先立つ母液層において中和反応が既に完結していることから、水酸化錫の被覆層の不均一な形成や、粒子の凝集を確実に防止することは容易でない。また、母液槽中に強分散装置を設置し、該強分散装置によって液を強分散しながら該母液槽中で中和反応を行った場合であっても、一般に強分散装置の容積に比して母液槽の容積の方が非常に大きいので、反応は不均一に進行し、水酸化錫の被覆層の不均一な形成や、粒子の凝集を確実に防止することはやはり容易でない。要するに、本実施形態では母液槽とは独立した強分散装置が設置された容器内において中和反応を行うのに対し、前記の特開２００５−１０８７３４号公報に記載の技術は、母液槽において中和反応を行う点で、本実施形態と全く相違するものである。 In Japanese Patent Application Laid-Open No. 2005-108734 related to the earlier application of the present applicant described in the background art section, unlike this embodiment, core material particles, a water-soluble tin compound, and an acid or an alkali are added to a mother liquor tank. Thus, a neutralization reaction is caused, and the neutralized liquid is dispersed with a strong dispersion device. Since the neutralization reaction proceeds very rapidly as described above, the neutralization reaction does not substantially occur in the strong dispersion apparatus. Therefore, even if the liquid is dispersed with a strong dispersion device, since the neutralization reaction has already been completed in the mother liquid layer preceding it, it is possible to ensure the formation of a non-uniform tin hydroxide coating layer and the aggregation of particles. It is not easy to prevent. Even if a strong dispersion apparatus is installed in the mother liquor tank and the neutralization reaction is carried out in the mother liquor tank while strongly dispersing the liquid with the strong dispersion apparatus, it is generally compared with the volume of the strong dispersion apparatus. Since the volume of the mother liquor tank is much larger, the reaction proceeds non-uniformly, and it is still not easy to reliably prevent non-uniform formation of the tin hydroxide coating layer and aggregation of particles. In short, in the present embodiment, the neutralization reaction is performed in a container in which a strong dispersion device independent of the mother liquor tank is installed, whereas the technique described in the above-mentioned Japanese Patent Application Laid-Open No. 2005-108734 is performed in the mother liquor tank. This is completely different from the present embodiment in that a sum reaction is performed.
水溶性錫化合物と酸又はアルカリとの反応は強分散装置１３において瞬時に完了するので、強分散装置１３に供給された酸又はアルカリが未反応のまま循環経路中に流出することや、循環する母液中に酸又はアルカリが蓄積して、強分散装置１３以外の箇所において中和反応が生ずることはほとんど起こり得ないか、又は起こったとしても、目的物の品質に影響を及ぼさない程度でしかない。 Since the reaction between the water-soluble tin compound and the acid or alkali is instantaneously completed in the strong dispersion device 13, the acid or alkali supplied to the strong dispersion device 13 flows out into the circulation path without being reacted or circulates. Acid or alkali accumulates in the mother liquor and a neutralization reaction hardly occurs at a place other than the strong dispersion device 13, or even if it occurs, it does not affect the quality of the target product. Absent.
局所的な中和反応が生じることを効果的に防止する観点から、強分散装置１３の容積はできるだけ小さいことが好ましい。一方、十分な処理量を確保する観点からは、強分散装置１３の容積Ｖ２は大きいことが好ましい。これらのバランスを考慮すると、強分散装置１３の容積Ｖ２は１〜１０００ｃｍ3、特に１０〜５００ｃｍ3であることが好ましい。 From the viewpoint of effectively preventing a local neutralization reaction from occurring, the volume of the strong dispersion device 13 is preferably as small as possible. On the other hand, from the viewpoint of securing a sufficient processing amount, the volume V2 of the strong dispersion device 13 is preferably large. Considering these balances, the volume V2 of the strong dispersion device 13 is preferably 1 to 1000 cm 3 , particularly preferably 10 to 500 cm 3 .
同様の観点から、強分散装置１３における攪拌部１３ａによる攪拌速度は５０００ｒｐｍ以上、特に１００００ｒｐｍ以上であることが好ましい。攪拌部１３ａによる攪拌速度の上限値に特に制限はなく高ければ高いほど好ましいが、１６０００ｒｐｍ程度に高速攪拌すれば、局所的な中和反応が生じることを効果的に防止することができる。 From the same viewpoint, the stirring speed by the stirring unit 13a in the strong dispersion device 13 is preferably 5000 rpm or more, particularly preferably 10,000 rpm or more. Although there is no restriction | limiting in particular in the upper limit of the stirring speed by the stirring part 13a, it is so preferable that it is high, but if high-speed stirring is carried out to about 16000 rpm, it can prevent effectively that local neutralization reaction arises.
上述の容積及び攪拌速度を有する強分散装置１３として好ましいものとしては、ホモジナイザやビーズミル等が挙げられる。これらのうちホモジナイザは、低コストで実設備に組み込み易いので特に好ましい。 Preferable examples of the strong dispersion device 13 having the above volume and stirring speed include a homogenizer and a bead mill. Among these, the homogenizer is particularly preferable because it is easy to incorporate into a real facility at a low cost.
強分散装置１３内における母液２０及び酸又はアルカリの滞留時間は、短ければ短いほど、局所的な中和反応の防止の観点から好ましい。具体的には、母液槽１１から流出し強分散装置１３に流入する母液２０の流速をＳ１（ｃｍ3／ｍｉｎ）とし、強分散装置１３に供給される酸又はアルカリの速度をＳ３（ｃｍ3／ｍｉｎ）とした場合、強分散装置１３の容積Ｖ２（ｃｍ3）との関係で、Ｖ２／（Ｓ１＋Ｓ３）の値が１〜６０秒、特に３０〜６０秒であることが好ましい。 The shorter the residence time of the mother liquor 20 and the acid or alkali in the strong dispersion device 13 is, the shorter is preferable from the viewpoint of preventing a local neutralization reaction. Specifically, the flow rate of the mother liquor 20 flowing out from the mother liquor tank 11 and flowing into the strong dispersion device 13 is S1 (cm 3 / min), and the rate of acid or alkali supplied to the strong dispersion device 13 is S3 (cm 3 / Min), the value of V2 / (S1 + S3) is preferably 1 to 60 seconds, particularly preferably 30 to 60 seconds, in relation to the volume V2 (cm 3 ) of the strong dispersion device 13.
強分散装置１３に流入する母液の量と酸又はアルカリの量との割合は、強分散装置１３における局所的な中和反応の防止に関連している。具体的には、強分散装置１３に供給される酸又はアルカリの速度Ｓ３と、母液槽１１から流出し強分散装置１３に流入する母液２０の流速Ｓ１との比であるＳ３／Ｓ１が０．０１〜０．０５、特に０．０３〜０．０５となるように両者の速度を調整することが好ましい。換言すれば、単位時間当たりの母液２０の供給量に対して、酸又はアルカリの供給量を圧倒的に少なくすることが好ましい。酸又はアルカリの供給量を少なくすることは、局所的な中和反応の防止の点からは非常に有効であるが、その反面、芯材粒子の表面に形成される水酸化錫の被覆層の形成速度の観点からはマイナスに作用する。このマイナスの点を、本実施形態においては、母液２０を循環することで解決している。 The ratio of the amount of mother liquor flowing into the strong dispersion device 13 and the amount of acid or alkali is related to the prevention of local neutralization reaction in the strong dispersion device 13. Specifically, S3 / S1, which is a ratio of the acid or alkali speed S3 supplied to the strong dispersion apparatus 13 and the flow rate S1 of the mother liquor 20 flowing out of the mother liquor tank 11 and flowing into the strong dispersion apparatus 13, is 0. It is preferable to adjust both speeds to be 01 to 0.05, particularly 0.03 to 0.05. In other words, it is preferable that the supply amount of acid or alkali is overwhelmingly smaller than the supply amount of the mother liquor 20 per unit time. Reducing the supply amount of acid or alkali is very effective from the viewpoint of preventing local neutralization reaction, but on the other hand, the coating layer of tin hydroxide formed on the surface of the core particle is not suitable. It acts negatively from the viewpoint of formation speed. This minus point is solved by circulating the mother liquor 20 in this embodiment.
処理量にもよるが、母液２０の流速Ｓ１が例えば１０〜１０００ｃｍ3／ｍｉｎである場合には、酸又はアルカリの速度Ｓ３は０．３〜５０ｃｍ3／ｍｉｎであることが好ましい。 Although depending on the amount of treatment, when the flow rate S1 of the mother liquor 20 is, for example, 10 to 1000 cm 3 / min, the acid or alkali speed S3 is preferably 0.3 to 50 cm 3 / min.
強分散装置１３における局所的な中和反応を防止する観点からは、酸又はアルカリの供給量を少なくすることに代えて、又はそれに加えて、供給する酸又はアルカリの濃度を低くすることも有効である。この観点から、酸又はアルカリの濃度は、母液２０に含まれる水溶性錫化合物の濃度が上述の範囲であることを条件として、規定度で表して１〜２５Ｎ、特に５〜２０Ｎであることが好ましい。 From the viewpoint of preventing local neutralization reaction in the strong dispersion device 13, it is also effective to reduce the concentration of the acid or alkali to be supplied instead of or in addition to reducing the amount of acid or alkali to be supplied. It is. From this point of view, the acid or alkali concentration is 1 to 25 N, particularly 5 to 20 N expressed in terms of normality, provided that the concentration of the water-soluble tin compound contained in the mother liquor 20 is in the above range. preferable.
強分散装置１３に供給される酸としては、例えば硫酸、硝酸、酢酸などの水溶液が用いられる。アルカリとしては、例えば水酸化ナトリウム水溶液やアンモニア水などが用いられる。 As the acid supplied to the strong dispersion device 13, for example, an aqueous solution of sulfuric acid, nitric acid, acetic acid or the like is used. As the alkali, for example, an aqueous sodium hydroxide solution or ammonia water is used.
強分散装置１３に供給される酸及びアルカリは連続的でもよく、或いは断続的でもよい。芯材粒子の表面に一層均一な水酸化錫の被覆層を形成する観点からは、酸又はアルカリを連続供給することが好ましい。供給には、例えばプランジャーポンプ等を用いることができる。 The acid and alkali supplied to the strong dispersion device 13 may be continuous or intermittent. From the viewpoint of forming a more uniform tin hydroxide coating layer on the surface of the core particles, it is preferable to continuously supply acid or alkali. For the supply, for example, a plunger pump or the like can be used.
酸又はアルカリは、循環の時間経過と共にその供給量（供給速度）及び／又は濃度を変化（例えば漸増又は漸減）させてもよい。例えば、供給量を変化させる場合には、容積が数百ｃｍ3〜数ｍ3の母液槽１１を用いたときには該供給量を０．１〜１０Ｌ／ｍｉｎの範囲で漸増又は漸減させることができる。一方、濃度を変化させる場合には、１〜５０重量％の範囲で漸増又は漸減させることができる。この操作によって、反応の終期における局所的な中和反応を効果的に防止することができる。 The acid or alkali may change (for example, gradually increase or decrease) its supply amount (supply rate) and / or concentration over time. For example, when changing the supply amount, when the mother liquor tank 11 having a volume of several hundred cm 3 to several m 3 is used, the supply amount can be gradually increased or decreased in the range of 0.1 to 10 L / min. . On the other hand, when the concentration is changed, it can be gradually increased or decreased in the range of 1 to 50% by weight. By this operation, a local neutralization reaction at the end of the reaction can be effectively prevented.
母液の循環時間に特に制限はなく、所望の厚みの被覆層が形成されるまで循環を行えばよい。本発明者らの検討の結果、循環開始から循環終了までの時間をＴ（ｍｉｎ）としたとき、上述のＳ１及びＶ１との関係で、Ｓ１Ｔ／Ｖ１の値が５以上、特に１０以上となるように循環を行うことで、満足すべき厚みの被覆層が形成されることが判明した。Ｓ１Ｔ／Ｖ１の上限値は、数百程度であれば満足すべき結果が得られる。 There is no particular limitation on the circulation time of the mother liquor, and circulation may be performed until a coating layer having a desired thickness is formed. As a result of the study by the present inventors, when the time from the start of circulation to the end of circulation is defined as T (min), the value of S1T / V1 is 5 or more, particularly 10 or more in relation to S1 and V1 described above. Thus, it was found that a coating layer having a satisfactory thickness was formed by performing the circulation. If the upper limit of S1T / V1 is about several hundreds, satisfactory results can be obtained.
本実施形態の変形例として、図２（ａ）及び（ｂ）に示す実施形態が挙げられる。図２（ａ）に示す実施形態は、図１に示す装置１０において、強分散装置１３を複数個用い、それらを循環流路に対して並列に設けた例である。この実施形態によれば処理量の増大を図れる。したがって、この実施形態は、各強分散装置１３の容積Ｖ２が小さい場合に特に有効である。 As a modification of the present embodiment, the embodiment shown in FIGS. 2A and 2B can be cited. The embodiment shown in FIG. 2A is an example in which a plurality of strong dispersion devices 13 are used in the device 10 shown in FIG. According to this embodiment, the amount of processing can be increased. Therefore, this embodiment is particularly effective when the volume V2 of each strong dispersion device 13 is small.
図２（ｂ）に示す実施形態は、図１に示す装置１０における、強分散装置１３を複数個用い、それらを循環流路に対して直列に設けた例である。この実施形態によれば、母液の強分散の増強を図ることができるので、母液２０の循環の回数を減らすことが可能になる。 The embodiment shown in FIG. 2B is an example in which a plurality of strong dispersion devices 13 are used in the device 10 shown in FIG. According to this embodiment, since the strong dispersion of the mother liquor can be enhanced, the number of circulations of the mother liquor 20 can be reduced.
水酸化錫の被覆層が形成された粒子どうしの凝集を一層効果的に防止する観点から、芯材粒子が分散してなる母液を母液槽１１に供給して、該母液を循環するのに先立ち、芯材粒子を分散処理に付すことが好ましい。また、芯材粒子を予め分散処理に付すことによって、装置をスケールアップしても得られる被覆粒子にばらつきが発生しづらく、量産性を高めることができるという利点もある。分散処理は、例えば芯材粒子と水等の媒体とを含むスラリーを、メディアミル又はメディアレスの分散装置によって処理することで行われる。メディアミルとしては、例えばビーズミル、サンドミル、ボールミル等を用いることができる。一方、メディアレスの分散装置としては、ホモジナイザやアルティマイザ等を用いることができる。メディアミル又はメディアレスの分散装置による分散条件は、その種類に応じ、芯材粒子が一次粒子にまで十分に分散するような条件を適宜適用すればよい。例えば芯材粒子の凝集の程度に応じ、１パスの分散処理を行ってもよく、あるいは循環方式で複数パスの分散処理を行ってもよい。具体的には、メディアミルとしてビーズミルを用いる場合、その運転条件として、ジルコニアビーズ（０．３ｍｍφ）を用い、周速８〜１２ｍ／ｓ、流量１０〜１８ｋｇ／ｈにて１〜１０パスの分散条件を採用することができる。一方、メディアレスの分散装置としてホモジナイザを用いる場合、その運転条件として、周速４０００〜１００００ｒｐｍ、流量５〜２０ｋｇ／ｈ、パス回数１〜２０回の分散条件を採用することができる。 From the viewpoint of more effectively preventing aggregation of particles on which the tin hydroxide coating layer is formed, the mother liquor in which the core material particles are dispersed is supplied to the mother liquor tank 11 prior to circulating the mother liquor. The core particles are preferably subjected to a dispersion treatment. Further, by subjecting the core material particles to the dispersion treatment in advance, there is an advantage that the coated particles obtained even when the apparatus is scaled up are less likely to vary, and mass productivity can be improved. The dispersion treatment is performed, for example, by treating a slurry containing core material particles and a medium such as water with a media mill or a medialess dispersion device. As the media mill, for example, a bead mill, a sand mill, a ball mill or the like can be used. On the other hand, a homogenizer, an optimizer, or the like can be used as a medialess dispersion apparatus. The dispersion conditions by the media mill or the medialess dispersion device may be appropriately applied so that the core particles are sufficiently dispersed to the primary particles according to the type. For example, depending on the degree of core particle aggregation, one-pass dispersion processing may be performed, or multiple-pass dispersion processing may be performed in a circulating manner. Specifically, when a bead mill is used as the media mill, zirconia beads (0.3 mmφ) are used as operating conditions, and a dispersion of 1 to 10 passes at a peripheral speed of 8 to 12 m / s and a flow rate of 10 to 18 kg / h. Conditions can be adopted. On the other hand, when a homogenizer is used as a medialess dispersion device, the operating conditions may be a dispersion condition of a peripheral speed of 4000 to 10000 rpm, a flow rate of 5 to 20 kg / h, and the number of passes of 1 to 20 times.
以上の方法によって、水酸化錫の被覆層が形成された粒子が得られる。この粒子においては、芯材粒子の表面全域にわたり被覆層が形成されていると共に、被覆層の厚みが均一になっている。また凝集した粒子の数が極めて少なくなっている。その結果、この粒子は、その粒度分布がシャープなものになっている。具体的には、粒度分布の指標であるＤ50／Ｄ90の値が好ましくは０．５〜１となる。 By the above method, particles having a tin hydroxide coating layer formed are obtained. In these particles, a coating layer is formed over the entire surface of the core particles, and the thickness of the coating layer is uniform. Also, the number of aggregated particles is extremely small. As a result, the particles have a sharp particle size distribution. Specifically, the value of D 50 / D 90 that is an index of particle size distribution is preferably 0.5 to 1.
このようにして得られた粒子は、反応系から分離され、洗浄及び乾燥工程を経た後に焼成工程に付される。それによって酸化錫で被覆された導電性粒子が得られる。その後、必要に応じて粉砕工程に付され、所望の粒径に調整される。この酸化錫で被覆された粒子においては、焼成前の粒子のシャープな粒度分布が維持されており、凝集が少なくなっている。具体的には、酸化錫で被覆された粒子は、粒度分布の指標であるＤ50／Ｄ90の値が、焼成前と同様に、好ましくは０．５〜１となる。 The particles thus obtained are separated from the reaction system and subjected to a firing step after washing and drying steps. Thereby, conductive particles coated with tin oxide are obtained. Thereafter, it is subjected to a pulverization step as necessary, and adjusted to a desired particle size. In the particles coated with tin oxide, the sharp particle size distribution of the particles before firing is maintained, and aggregation is reduced. Specifically, the particles coated with tin oxide preferably have a value of D 50 / D 90 that is an index of particle size distribution, which is preferably 0.5 to 1, as before firing.
前記の焼成工程は、非酸化性雰囲気中で行うことが好ましい。非酸化性雰囲気としては、例えば窒素雰囲気、水素を含有した窒素雰囲気、アルゴン雰囲気等が挙げられる。これらのうち、水素を含有した窒素雰囲気は安価なので、工業的観点から好ましい。また、水素を含有した窒素雰囲気を用いる場合、水素の含有量は、好ましくは０．１〜１０体積％、更に好ましくは１〜３体積％である。水素の含有量がこの範囲内にあると、錫を金属に還元させることなく、酸素欠損を有する導電性の酸化錫の被覆層を形成しやすいからである。 The firing step is preferably performed in a non-oxidizing atmosphere. Examples of the non-oxidizing atmosphere include a nitrogen atmosphere, a nitrogen atmosphere containing hydrogen, and an argon atmosphere. Among these, a nitrogen atmosphere containing hydrogen is preferable from an industrial viewpoint because it is inexpensive. Moreover, when using nitrogen atmosphere containing hydrogen, content of hydrogen becomes like this. Preferably it is 0.1-10 volume%, More preferably, it is 1-3 volume%. This is because, when the hydrogen content is within this range, it is easy to form a conductive tin oxide coating layer having oxygen vacancies without reducing tin to metal.
前記の焼成工程における焼成温度は、好ましくは２００〜１２００℃、更に好ましくは４００〜６００℃である。焼成時間は、好ましくは５〜１８０分、更に好ましくは１０〜１２０分である。焼成温度及び時間がこれらの範囲内にあると、酸素欠損を生じさせるのに十分であり、且つ凝集を起こし難いからである。この焼成工程を行うことにより導電性粒子が得られる。 The firing temperature in the firing step is preferably 200 to 1200 ° C, more preferably 400 to 600 ° C. The firing time is preferably 5 to 180 minutes, more preferably 10 to 120 minutes. This is because if the firing temperature and time are within these ranges, it is sufficient to cause oxygen vacancies and hardly cause aggregation. Conductive particles are obtained by performing this firing step.
このようにして得られた導電性粒子は、例えば紙、プラスチック、ゴム、樹脂、塗料等に添加してこれらに導電性を付与する導電性フィラーとして使用される。また、電池等の電極改質剤として使用される。 The conductive particles thus obtained are used, for example, as a conductive filler that is added to paper, plastic, rubber, resin, paint, etc. to impart conductivity to them. It is also used as an electrode modifier for batteries and the like.
以上、本発明をその好ましい実施形態に基づき説明したが、本発明は前記実施形態に制限されない。例えば前記の実施形態で用いられた製造装置１０に代えて、図３に示す装置１０’を用いることもできる。図３に示す装置１０’においては、母液槽１１の底部に強分散装置１３が直接取り付けられている。同図に示す装置１０’を用いても、図１に示す装置１０と同様の有利な効果が奏される。 As mentioned above, although this invention was demonstrated based on the preferable embodiment, this invention is not restrict | limited to the said embodiment. For example, instead of the manufacturing apparatus 10 used in the above embodiment, an apparatus 10 ′ shown in FIG. 3 can be used. In the apparatus 10 ′ shown in FIG. 3, a strong dispersion apparatus 13 is directly attached to the bottom of the mother liquor tank 11. Even when the apparatus 10 'shown in the figure is used, the same advantageous effects as the apparatus 10 shown in FIG.
また前記実施形態は、本発明を、芯材粒子の表面に水酸化錫の被覆層を形成する方法に適用した例であるが、本発明はこれ以外の被覆粒子の製造方法にも同様に適用できる。例えば、芯材粒子の表面に、無電解めっきによりめっき層を形成する方法に本発明を適用することができる。この場合には、母液中に芯材粒子及びめっき金属源となる化合物を含有させておき、強分散装置に還元剤を供給すればよい。また、芯材粒子の表面に、水酸化亜鉛の被覆層を形成する方法に、本発明を適用することもできる。この場合には、母液中に芯材粒子及び塩化亜鉛等の亜鉛源となる水溶性亜鉛化合物を含有させておき、強分散装置に水酸化ナトリウム等のアルカリを供給すればよい。このようにして得られた粒子を大気中で焼成することによって、酸化亜鉛で被覆された導電性粒子を得ることができる。さらに、芯材粒子の表面に、インジウム及び錫の水酸化物からなる被覆層を形成する方法に、本発明を適用することもできる。この場合には、母液中に芯材粒子並びに硝酸インジウム等のインジウム源となる水溶性インジウム化合物及び塩化錫等の錫源となる水溶性錫化合物を含有させておき、強分散装置に水酸化ナトリウム等のアルカリを供給すればよい。このようにして得られた粒子を還元雰囲気中で焼成することによって、インジウム及び錫の複合酸化物（ＩＴＯ）で被覆された導電性粒子を得ることができる。 Moreover, although the said embodiment is an example which applied this invention to the method of forming the coating layer of a tin hydroxide on the surface of core material particle | grains, this invention is similarly applied to the manufacturing method of other coating particles. it can. For example, the present invention can be applied to a method of forming a plating layer on the surface of core material particles by electroless plating. In this case, the reducing agent may be supplied to the strong dispersion device by containing the core particles and the compound serving as the plating metal source in the mother liquor. The present invention can also be applied to a method of forming a zinc hydroxide coating layer on the surface of the core particles. In this case, the mother liquor may contain core particles and a water-soluble zinc compound that serves as a zinc source such as zinc chloride, and an alkali such as sodium hydroxide may be supplied to the strong dispersion device. By firing the particles thus obtained in the air, conductive particles coated with zinc oxide can be obtained. Furthermore, the present invention can also be applied to a method of forming a coating layer made of a hydroxide of indium and tin on the surface of the core material particles. In this case, the mother liquor contains core particles and a water-soluble indium compound serving as an indium source such as indium nitrate and a water-soluble tin compound serving as a tin source such as tin chloride. What is necessary is just to supply alkalis, such as. By firing the particles thus obtained in a reducing atmosphere, conductive particles coated with a composite oxide of indium and tin (ITO) can be obtained.
以下、実施例により本発明を更に詳細に説明する。しかしながら本発明の範囲はかかる実施例に制限されない。特に断らない限り、「％」は「重量％」を意味する。 Hereinafter, the present invention will be described in more detail with reference to examples. However, the scope of the present invention is not limited to such examples. Unless otherwise specified, “%” means “% by weight”.
〔実施例１〕
図１に示す装置を用い、水酸化錫で被覆された粒子を製造した。母液槽中に純水３５００ｃｍ3を投入し、次に平均粒径Ｄ50が０．１μｍである球状のアルミナ芯材９００ｇを投入して５パス循環させた。母液槽から流出するスラリーの流速は２２８０ｃｍ3／ｍｉｎであった。また強分散装置の攪拌速度は１６０００ｒｐｍとした。循環完了後のスラリーを純水で全量９０００ｃｍ3にメスアップし、そこに１６００ｇの錫酸ナトリウムを投入して５パス循環させた。このようにして母液を得た。この母液を、母液槽から流出する流速Ｓ１が２００ｃｍ3となるように循環させながら、強分散装置としてのホモジナイザ（ＩＫＡジャパン株式会社製のＴ５０（商品名））に２０％硫酸を供給した。供給速度Ｓ３は９．２ｃｍ3／ｍｉｎであった。ホモジナイザの容積は５００ｃｍ3、攪拌速度は１６０００ｒｐｍであった。循環を１５分間行い、その間硫酸を連続的にホモジナイザに供給した。このようにして、アルミナ芯材の表面に水酸化錫の被覆層が形成された粒子を得た。
[Example 1]
Using the apparatus shown in FIG. 1, particles coated with tin hydroxide were produced. 3500 cm 3 of pure water was introduced into the mother liquor, and then 900 g of spherical alumina core material having an average particle diameter D 50 of 0.1 μm was introduced and circulated for 5 passes. The flow rate of the slurry flowing out from the mother liquor was 2280 cm 3 / min. The stirring speed of the strong dispersion apparatus was 16000 rpm. After completion of the circulation, the slurry was made up to a total volume of 9000 cm 3 with pure water, and 1600 g of sodium stannate was added thereto to circulate for 5 passes. A mother liquor was thus obtained. While this mother liquor was circulated so that the flow rate S1 flowing out of the mother liquor was 200 cm 3 , 20% sulfuric acid was supplied to a homogenizer (T50 (trade name) manufactured by IKA Japan Co., Ltd.) as a strong dispersion device. The supply speed S3 was 9.2 cm 3 / min. The volume of the homogenizer was 500 cm 3 and the stirring speed was 16000 rpm. Circulation was carried out for 15 minutes, during which time sulfuric acid was continuously fed to the homogenizer. In this manner, particles having a tin hydroxide coating layer formed on the surface of the alumina core material were obtained.
得られた粒子を含むスラリーを、その導電率が６００μＳ／ｃｍ以下となるまでリパルプ洗浄した後、ヌッチェ濾過を行い、ケーキを得た。このケーキを大気中、１５０℃で１０時間乾燥させた。次いで乾燥ケーキを粉砕し、その粉砕粉を１体積％Ｈ2／Ｎ2雰囲気下で４５０℃、３０分間還元焼成した。これによって、アルミナ芯材の表面に酸化錫の被覆層が形成された導電性粒子を得た。 The slurry containing the obtained particles was repulp washed until the conductivity became 600 μS / cm or less, and then subjected to Nutsche filtration to obtain a cake. This cake was dried in air at 150 ° C. for 10 hours. Next, the dried cake was pulverized, and the pulverized powder was reduced and fired at 450 ° C. for 30 minutes in a 1% by volume H 2 / N 2 atmosphere. Thus, conductive particles having a tin oxide coating layer formed on the surface of the alumina core material were obtained.
〔実施例２〕
実施例１において用いたアルミナ芯材に代えて、平均粒径Ｄ50が０．１μｍである球状の二酸化珪素芯材９００ｇを用いた。これ以外は実施例１と同様にして、二酸化珪素芯材の表面に水酸化錫の被覆層が形成された粒子を得た。得られた粒子を含むスラリーを、その導電率が６００μＳ／ｃｍ以下となるまでリパルプ洗浄した後、ヌッチェ濾過を行い、ケーキを得た。このケーキを大気中、１５０℃で１０時間乾燥させた。次いで乾燥ケーキを粉砕し、その粉砕粉を１体積％Ｈ2／Ｎ2雰囲気下で７００℃、１時間還元焼成した。これによって、二酸化珪素芯材の表面に酸化錫の被覆層が形成された導電性粒子を得た。
[Example 2]
Instead of the alumina core material used in Example 1, 900 g of a spherical silicon dioxide core material having an average particle diameter D 50 of 0.1 μm was used. Except this, it carried out similarly to Example 1, and obtained the particle | grains in which the coating layer of the tin hydroxide was formed in the surface of the silicon dioxide core material. The slurry containing the obtained particles was repulp washed until the conductivity became 600 μS / cm or less, and then subjected to Nutsche filtration to obtain a cake. This cake was dried in air at 150 ° C. for 10 hours. Next, the dried cake was pulverized, and the pulverized powder was reduced and fired at 700 ° C. for 1 hour in an atmosphere of 1% by volume H 2 / N 2 . Thus, conductive particles having a tin oxide coating layer formed on the surface of the silicon dioxide core material were obtained.
〔実施例３〕
図３に示す装置を用い、水酸化錫で被覆された粒子を製造した。母液槽中に純水３５００ｃｍ3を投入し、次に平均粒径Ｄ50が０．１５μｍである球状の酸化チタン芯材９００ｇを投入して５パス循環させた。母液槽から流出するスラリーの流速は２２８０ｃｍ3／ｍｉｎであった。また強分散装置の攪拌速度は１６０００ｒｐｍとした。循環完了後のスラリーを純水で全量９０００ｃｍ3にメスアップし、そこに９００ｇの錫酸ナトリウムを投入して５パス循環させた。このようにして母液を得た。この母液を、母液槽から流出する流速Ｓ１が２００ｃｍ3となるように循環させながら、強分散装置としてのホモジナイザ（ＩＫＡジャパン株式会社製のｍａｇｉｃ ＬＡＢ（商品名））に２０％硫酸を供給した。供給速度Ｓ３は９．２ｃｍ3／ｍｉｎであった。ホモジナイザの容積は２０ｃｍ3、攪拌速度は１６０００ｒｐｍであった。循環を１５分間行い、その間硫酸を連続的にホモジナイザに供給した。このようにして、酸化チタン芯材の表面に水酸化錫の被覆層が形成された粒子を得た。
Example 3
Using the apparatus shown in FIG. 3, particles coated with tin hydroxide were produced. Pure water 3500 cm 3 was charged into the mother liquor, and then 900 g of a spherical titanium oxide core material having an average particle diameter D 50 of 0.15 μm was charged and circulated for 5 passes. The flow rate of the slurry flowing out from the mother liquor was 2280 cm 3 / min. The stirring speed of the strong dispersion apparatus was 16000 rpm. After completion of the circulation, the slurry was made up to a total volume of 9000 cm 3 with pure water, and 900 g of sodium stannate was added thereto for circulation in 5 passes. A mother liquor was thus obtained. While this mother liquor was circulated so that the flow rate S1 flowing out from the mother liquor was 200 cm 3 , 20% sulfuric acid was supplied to a homogenizer (magic LAB (trade name) manufactured by IKA Japan Co., Ltd.) as a strong dispersion device. The supply speed S3 was 9.2 cm 3 / min. The volume of the homogenizer was 20 cm 3 and the stirring speed was 16000 rpm. Circulation was carried out for 15 minutes, during which time sulfuric acid was continuously fed to the homogenizer. In this way, particles having a tin hydroxide coating layer formed on the surface of the titanium oxide core material were obtained.
得られた粒子を含むスラリーを、その導電率が６００μＳ／ｃｍ以下となるまでリパルプ洗浄した後、ヌッチェ濾過を行い、ケーキを得た。このケーキを大気中、１５０℃で１０時間乾燥させた。次いで乾燥ケーキを粉砕し、その粉砕粉を１体積％Ｈ2／Ｎ2雰囲気下で４５０℃、３０分間還元焼成した。これによって、酸化チタン芯材の表面に酸化錫の被覆層が形成された導電性粒子を得た。得られた導電性粒子のＴＥＭ像を図４に示す。 The slurry containing the obtained particles was repulp washed until the conductivity became 600 μS / cm or less, and then subjected to Nutsche filtration to obtain a cake. This cake was dried in air at 150 ° C. for 10 hours. Next, the dried cake was pulverized, and the pulverized powder was reduced and fired at 450 ° C. for 30 minutes in a 1% by volume H 2 / N 2 atmosphere. Thus, conductive particles having a tin oxide coating layer formed on the surface of the titanium oxide core material were obtained. A TEM image of the obtained conductive particles is shown in FIG.
〔実施例４〕
図３に示す装置を用い、水酸化錫で被覆された粒子を製造した。母液槽中に純水３５００ｃｍ3を投入し、次に平均粒径Ｄ50が０．１５μｍである球状の硫酸バリウム芯材９００ｇを投入して５パス循環させた。母液槽から流出するスラリーの流速は２２８０ｃｍ3／ｍｉｎであった。また強分散装置の攪拌速度は１６０００ｒｐｍとした。循環完了後のスラリーを純水で全量９０００ｃｍ3にメスアップし、そこに１６００ｇの錫酸ナトリウム及び２．３ｃｍ3の水酸化ナトリウム水溶液（濃度２５Ｎ）を投入して５パス循環させた。このようにして母液を得た。この母液を、母液槽から流出する流速Ｓ１が２００ｃｍ3となるように循環させながら、強分散装置としてのホモジナイザ（ＩＫＡジャパン株式会社製のｍａｇｉｃ ＬＡＢ（商品名））に２０％硫酸を供給した。供給速度Ｓ３は９．２ｃｍ3／ｍｉｎであった。ホモジナイザの容積は２０ｃｍ3、攪拌速度は１６０００ｒｐｍであった。循環を１５分間行い、その間硫酸を連続的にホモジナイザに供給した。このようにして、硫酸バリウム芯材の表面に水酸化錫の被覆層が形成された粒子を得た。
Example 4
Using the apparatus shown in FIG. 3, particles coated with tin hydroxide were produced. Pure water 3500 cm 3 was charged into the mother liquor, and then 900 g of a spherical barium sulfate core material having an average particle diameter D 50 of 0.15 μm was charged and circulated for 5 passes. The flow rate of the slurry flowing out from the mother liquor was 2280 cm 3 / min. The stirring speed of the strong dispersion apparatus was 16000 rpm. The slurry after circulation completion females up to a total volume of 9000 cm 3 with pure water and there is 5 the path circulated by introduction of sodium stannate and 2.3 cm 3 of an aqueous sodium hydroxide solution (concentration 25 N) of 1600 g. A mother liquor was thus obtained. While this mother liquor was circulated so that the flow rate S1 flowing out from the mother liquor was 200 cm 3 , 20% sulfuric acid was supplied to a homogenizer (magic LAB (trade name) manufactured by IKA Japan Co., Ltd.) as a strong dispersion device. The supply speed S3 was 9.2 cm 3 / min. The volume of the homogenizer was 20 cm 3 and the stirring speed was 16000 rpm. Circulation was carried out for 15 minutes, during which time sulfuric acid was continuously fed to the homogenizer. In this way, particles having a tin hydroxide coating layer formed on the surface of the barium sulfate core material were obtained.
得られた粒子を含むスラリーを、その導電率が６００μＳ／ｃｍ以下となるまでリパルプ洗浄した後、ヌッチェ濾過を行い、ケーキを得た。このケーキを大気中、１５０℃で１０時間乾燥させた。次いで乾燥ケーキを粉砕し、その粉砕粉を１体積％Ｈ2／Ｎ2雰囲気下で４５０℃、４５分間還元焼成した。これによって、硫酸バリウム芯材の表面に酸化錫の被覆層が形成された導電性粒子を得た。 The slurry containing the obtained particles was repulp washed until the conductivity became 600 μS / cm or less, and then subjected to Nutsche filtration to obtain a cake. This cake was dried in air at 150 ° C. for 10 hours. Next, the dried cake was pulverized, and the pulverized powder was reduced and fired at 450 ° C. for 45 minutes in a 1% by volume H 2 / N 2 atmosphere. As a result, conductive particles having a tin oxide coating layer formed on the surface of the barium sulfate core material were obtained.
〔実施例５〕
図１に示す装置を用い、水酸化亜鉛で被覆された粒子を製造した。母液槽中に純水３５００ｃｍ3を投入し、次に平均粒径Ｄ50が０．１５μｍである球状の硫酸バリウム芯材９００ｇを投入して５パス循環させた。母液槽から流出するスラリーの流速は２２８０ｃｍ3／ｍｉｎであった。また強分散装置の攪拌速度は１６０００ｒｐｍとした。循環完了後のスラリーを純水で全量９０００ｃｍ3にメスアップし、そこに１０００ｇの無水塩化亜鉛を投入して５パス循環させた。このようにして母液を得た。この母液を、母液槽から流出する流速Ｓ１が１０Ｌ／ｍｉｎとなるように循環させながら、強分散装置としてのホモジナイザ（ＩＫＡジャパン株式会社製のＴ５０（商品名））に２０％水酸化ナトリウム水溶液を供給した。供給速度Ｓ３は９．２ｃｍ3／ｍｉｎであった。ｐＨは５．０とした。ホモジナイザの容積は５００ｃｍ3、攪拌速度は１６０００ｒｐｍであった。循環を１５分間行い、その間硫酸を連続的にホモジナイザに供給した。このようにして、硫酸バリウム芯材の表面に水酸化亜鉛の被覆層が形成された粒子を得た。
Example 5
Using the apparatus shown in FIG. 1, particles coated with zinc hydroxide were produced. Pure water 3500 cm 3 was charged into the mother liquor, and then 900 g of a spherical barium sulfate core material having an average particle diameter D 50 of 0.15 μm was charged and circulated for 5 passes. The flow rate of the slurry flowing out from the mother liquor was 2280 cm 3 / min. The stirring speed of the strong dispersion apparatus was 16000 rpm. After completion of the circulation, the slurry was made up to a total volume of 9000 cm 3 with pure water, and 1000 g of anhydrous zinc chloride was added thereto for circulation in 5 passes. A mother liquor was thus obtained. While this mother liquor is circulated so that the flow rate S1 flowing out from the mother liquor is 10 L / min, a 20% aqueous sodium hydroxide solution is added to a homogenizer (T50 (trade name) manufactured by IKA Japan Co., Ltd.) as a strong dispersion device. Supplied. The supply speed S3 was 9.2 cm 3 / min. The pH was 5.0. The volume of the homogenizer was 500 cm 3 and the stirring speed was 16000 rpm. Circulation was carried out for 15 minutes, during which time sulfuric acid was continuously fed to the homogenizer. In this manner, particles having a zinc hydroxide coating layer formed on the surface of the barium sulfate core material were obtained.
得られた粒子を含むスラリーを、その導電率が６００μＳ／ｃｍ以下となるまでリパルプ洗浄した後、ヌッチェ濾過を行い、ケーキを得た。このケーキを大気中、１５０℃で１０時間乾燥させた。次いで乾燥ケーキを粉砕し、その粉砕粉を大気中、４５０℃で、４５分還元焼成した。これによって、硫酸バリウム芯材の表面に酸化亜鉛の被覆層が形成された導電性粒子を得た。酸化亜鉛の被覆率は４０％であった。 The slurry containing the obtained particles was repulp washed until the conductivity became 600 μS / cm or less, and then subjected to Nutsche filtration to obtain a cake. This cake was dried in air at 150 ° C. for 10 hours. Next, the dried cake was pulverized, and the pulverized powder was reduced and fired at 450 ° C. for 45 minutes in the air. As a result, conductive particles having a zinc oxide coating layer formed on the surface of the barium sulfate core material were obtained. The coverage of zinc oxide was 40%.
〔実施例６〕
図１に示す装置を用い、インジウム及び錫の水酸化物で被覆された粒子を製造した。母液槽中に純水３５００ｃｍ3を投入し、次に平均粒径Ｄ50が０．１μｍである球状のアルミナ芯材９００ｇを投入して５パス循環させた。母液槽から流出するスラリーの流速は２２８０ｃｍ3／ｍｉｎであった。また強分散装置の攪拌速度は１６０００ｒｐｍとした。循環完了後のスラリーを純水で全量９０００ｃｍ3にメスアップし、そこに５ｇの塩化スズ塩酸溶液（４４％）及び９７６ｇの硝酸インジウム水溶液（１００ｇ／１０００ｃｍ3、比重１．６ｇ／ｃｍ3）の錫酸ナトリウムを投入して５パス循環させた。このようにして母液を得た。この母液を、母液槽から流出する流速Ｓ１が１０Ｌ／ｍｉｎとなるように循環させながら、強分散装置としてのホモジナイザ（ＩＫＡジャパン株式会社製のＴ５０（商品名））に２０％水酸化ナトリウムを供給した。供給速度Ｓ３は９．２ｃｍ3／ｍｉｎであった。ｐＨは３．０とした。ホモジナイザの容積は５００ｃｍ3、攪拌速度は１６０００ｒｐｍであった。循環を１５分間行い、その間硫酸を連続的にホモジナイザに供給した。このようにして、硫酸バリウム芯材の表面にインジウム及び錫の水酸化物の被覆層が形成された粒子を得た。
Example 6
Particles coated with indium and tin hydroxide were produced using the apparatus shown in FIG. 3500 cm 3 of pure water was introduced into the mother liquor, and then 900 g of spherical alumina core material having an average particle diameter D 50 of 0.1 μm was introduced and circulated for 5 passes. The flow rate of the slurry flowing out from the mother liquor was 2280 cm 3 / min. The stirring speed of the strong dispersion apparatus was 16000 rpm. The slurry after the circulation was made up to a total volume of 9000 cm 3 with pure water, and 5 g of tin chloride hydrochloric acid solution (44%) and 976 g of indium nitrate aqueous solution (100 g / 1000 cm 3 , specific gravity 1.6 g / cm 3 ) Sodium stannate was added and circulated for 5 passes. A mother liquor was thus obtained. While this mother liquor is circulated so that the flow rate S1 flowing out from the mother liquor tank is 10 L / min, 20% sodium hydroxide is supplied to a homogenizer (T50 (trade name) manufactured by IKA Japan Co., Ltd.) as a strong dispersion device. did. The supply speed S3 was 9.2 cm 3 / min. The pH was 3.0. The volume of the homogenizer was 500 cm 3 and the stirring speed was 16000 rpm. Circulation was carried out for 15 minutes, during which time sulfuric acid was continuously fed to the homogenizer. In this way, particles were obtained in which a coating layer of indium and tin hydroxide was formed on the surface of the barium sulfate core material.
得られた粒子を含むスラリーを、その導電率が６００μＳ／ｃｍ以下となるまでリパルプ洗浄した後、ヌッチェ濾過を行い、ケーキを得た。このケーキを大気中、１５０℃で１０時間乾燥させた。次いで乾燥ケーキを粉砕し、その粉砕粉を１体積％Ｈ2／Ｎ2雰囲気下で４５０℃、４５分還元焼成した。これによって、硫酸バリウム芯材の表面にインジウム及び錫の複合酸化物（ＩＴＯ）の被覆層が形成された導電性粒子を得た。ＩＴＯの被覆率は１０％であった。 The slurry containing the obtained particles was repulp washed until the conductivity became 600 μS / cm or less, and then subjected to Nutsche filtration to obtain a cake. This cake was dried in air at 150 ° C. for 10 hours. Next, the dried cake was pulverized, and the pulverized powder was reduced and fired at 450 ° C. for 45 minutes in a 1% by volume H 2 / N 2 atmosphere. As a result, conductive particles were obtained in which a coating layer of indium and tin composite oxide (ITO) was formed on the surface of the barium sulfate core material. The coverage of ITO was 10%.
〔実施例７〕
実施例１において、図１に示す装置に母液を投入する前に、該母液をビーズミルによる分散処理に付した。分散処理の条件は、濃度２０％、ジルコニアビーズ（０．３ｍｍφ）、周速８ｍ／ｓ、流量１０ｋｇ／ｈ、５パスの分散とした。分散処理後、実施例１と同様の操作を行いアルミナ芯材の表面に水酸化錫の被覆層が形成された粒子を得た。この粒子について実施例１と同様の操作を行い、アルミナ芯材の表面に酸化錫の被覆層が形成された導電性粒子を得た。
Example 7
In Example 1, the mother liquor was subjected to a dispersion treatment using a bead mill before the mother liquor was charged into the apparatus shown in FIG. The conditions for the dispersion treatment were a concentration of 20%, zirconia beads (0.3 mmφ), a peripheral speed of 8 m / s, a flow rate of 10 kg / h, and a 5-pass dispersion. After the dispersion treatment, the same operation as in Example 1 was performed to obtain particles in which a tin hydroxide coating layer was formed on the surface of the alumina core material. The particles were subjected to the same operation as in Example 1 to obtain conductive particles in which a tin oxide coating layer was formed on the surface of the alumina core material.
〔実施例８〜１２〕
実施例２〜６において、図１に示す装置に母液を投入する前に、該母液を、０．３ｍｍφのジルコニアビーズを用いたビーズミルによる分散処理に付した。分散処理の条件は表１に示すとおりとした。分散処理後、実施例２〜６と同様の操作を行い芯材粒子の表面に被覆層が形成された粒子を得た。各粒子について、洗浄、乾燥及び焼成を、実施例２〜６の条件と同様の条件で行い、芯材粒子の表面に酸化物の被覆層が形成された導電性粒子を得た。すなわち、実施例８においては実施例２と同様の条件、実施例９は実施例３と同様の条件、実施例１０は実施例４と同様の条件、実施例１１は実施例５と同様の条件、実施例１２は実施例６と同様の条件を採用した。
[Examples 8 to 12]
In Examples 2 to 6, before introducing the mother liquor into the apparatus shown in FIG. 1, the mother liquor was subjected to a dispersion treatment by a bead mill using 0.3 mmφ zirconia beads. The conditions for the dispersion treatment were as shown in Table 1. After the dispersion treatment, the same operations as in Examples 2 to 6 were performed to obtain particles having a coating layer formed on the surface of the core material particles. About each particle | grain, washing | cleaning, drying, and baking were performed on the conditions similar to the conditions of Examples 2-6, and the electroconductive particle in which the oxide coating layer was formed in the surface of core material particle | grains was obtained. That is, in Example 8, the same conditions as in Example 2, Example 9 in the same conditions as in Example 3, Example 10 in the same conditions as in Example 4, and Example 11 in the same conditions as in Example 5. In Example 12, the same conditions as in Example 6 were adopted.
〔実施例１３〕
実施例４において、図３に示す装置に母液を投入する前に、該母液をアルティマイザＨＪＰ−２５０３０（株式会社スギノマシン製）を用いて分散処理した。処理条件は、２０００ｋＰａ、スラリー温度４０℃、通液回数１０回とした。これ以外は実施例４と同様にして、硫酸バリウム芯材の表面に酸化錫の被覆層が形成された導電性粒子を得た。
Example 13
In Example 4, before introducing the mother liquor into the apparatus shown in FIG. 3, the mother liquor was subjected to dispersion treatment using an optimizer HJP-25030 (manufactured by Sugino Machine Co., Ltd.). The treatment conditions were 2000 kPa, slurry temperature 40 ° C., and the number of liquid passages 10 times. Except this, it carried out similarly to Example 4, and obtained the electroconductive particle by which the coating layer of the tin oxide was formed in the surface of the barium sulfate core material.
〔実施例１４〕
実施例５において、図１に示す装置に母液を投入する前に、該母液をホモジナイザとしてのＬＰＮナノジナイザー（セレンディップ製）を用いて分散処理した。処理条件は、５００ｋＰａ、スラリー温度４０℃、通液回数２０回とした。これ以外は実施例５と同様にして、硫酸バリウム芯材の表面に酸化亜鉛の被覆層が形成された導電性粒子を得た。
Example 14
In Example 5, before introducing the mother liquor into the apparatus shown in FIG. 1, the mother liquor was subjected to a dispersion treatment using an LPN nanogenizer (manufactured by Serendip) as a homogenizer. The treatment conditions were 500 kPa, slurry temperature 40 ° C., and the number of liquid passages 20 times. Except this, it carried out similarly to Example 5, and obtained the electroconductive particle by which the coating layer of the zinc oxide was formed in the surface of the barium sulfate core material.
〔比較例１〕
攪拌槽中に純水３５００ｃｍ3を投入し、次に平均粒径Ｄ50が０．１５μｍである球状の酸化チタン芯材９００ｇを投入して液を攪拌した。得られたスラリーを純水で全量９０００ｃｍ3にメスアップし、そこに９３０ｇの錫酸ナトリウムを投入して４０℃で１時間攪拌した。このスラリーを７０℃に昇温した後、２０％硫酸を１３００ｃｍ3供給し、スラリーのｐＨを３にした。その後、更に１時間攪拌を行った。このようにして酸化チタン芯材の表面に水酸化錫の被覆層が形成された粒子を得た。
[Comparative Example 1]
3500 cm 3 of pure water was charged into the stirring tank, and then 900 g of a spherical titanium oxide core material having an average particle diameter D 50 of 0.15 μm was charged to stir the liquid. The resulting slurry was made up to a total volume of 9000 cm 3 with pure water, and 930 g of sodium stannate was added thereto and stirred at 40 ° C. for 1 hour. After raising the temperature of the slurry to 70 ° C., 1300 cm 3 of 20% sulfuric acid was supplied to adjust the pH of the slurry to 3. Thereafter, the mixture was further stirred for 1 hour. In this way, particles having a tin hydroxide coating layer formed on the surface of the titanium oxide core material were obtained.
得られた粒子を含むスラリーを、その導電率が６００μＳ／ｃｍ以下となるまでリパルプ洗浄した後、ヌッチェ濾過を行い、ケーキを得た。このケーキを大気中、１５０℃で１０時間乾燥させた。次いで乾燥ケーキを粉砕し、その粉砕粉を１体積％Ｈ2／Ｎ2雰囲気下で４５０℃、３０分間還元焼成した。これによって、酸化チタン芯材の表面に酸化錫の被覆層が形成された導電性粒子を得た。得られた導電性粒子のＴＥＭ像を図５に示す。 The slurry containing the obtained particles was repulp washed until the conductivity became 600 μS / cm or less, and then subjected to Nutsche filtration to obtain a cake. This cake was dried in air at 150 ° C. for 10 hours. Next, the dried cake was pulverized, and the pulverized powder was reduced and fired at 450 ° C. for 30 minutes in a 1% by volume H 2 / N 2 atmosphere. Thus, conductive particles having a tin oxide coating layer formed on the surface of the titanium oxide core material were obtained. A TEM image of the obtained conductive particles is shown in FIG.
〔比較例２〕
比較例１において用いた酸化チタン芯材に代えて、平均粒径Ｄ50が０．１５μｍである球状の硫酸バリウム芯材９００ｇを用いた。また、錫酸ナトリウム１６００ｇを用い、比較例１と同様の条件で、硫酸バリウム芯材の表面に水酸化錫の被覆層が形成された粒子を得た。その後の洗浄、乾燥及び焼成は実施例４と同様にして、硫酸バリウム芯材の表面に酸化錫の被覆層が形成された導電性粒子を得た。
[Comparative Example 2]
Instead of the titanium oxide core material used in Comparative Example 1, 900 g of a spherical barium sulfate core material having an average particle diameter D 50 of 0.15 μm was used. In addition, using 1600 g of sodium stannate, particles having a tin hydroxide coating layer formed on the surface of the barium sulfate core material were obtained under the same conditions as in Comparative Example 1. Subsequent washing, drying and firing were performed in the same manner as in Example 4 to obtain conductive particles in which a tin oxide coating layer was formed on the surface of the barium sulfate core material.
〔比較例３〕
図１に示す装置を用い、特開２００５−１０８７３４号公報の実施例１に記載の方法に準じて被覆粒子を製造した。母液槽中に純水３５ｌ０ｃｍ3を投入し、次に平均粒径Ｄ50が０．１５μｍである球状の硫酸バリウム芯材２００ｇを投入して、硫酸バリウムの粗粒がなくなるまで分散させてスラリーを生成した。該スラリーに錫酸ナトリウム５７６ｇを投入し、これを溶解させた。スラリー中のＳｎ濃度は４１％であった。該スラリーに２０％硫酸をスラリーのｐＨが２．５になるまで添加して中和した。母液槽における中和の開始と同時に、第１ポンプ、ホモジナイザ及び第２ポンプを順次起動して母液槽中のスラリーをホモジナイザに送液して強分散処理を行い、強分散処理後のスラリーを反応槽に戻すようにした。ホモジナイザは、４５００ｒｐｍで攪拌させた。中和を開始してから終了するまでの９８分間にわたり強分散処理を行い続けた。このようにして、硫酸バリウム芯材の表面に水酸化錫の被覆層が形成された粒子を得た。その後は実施例４と同様にして、硫酸バリウム芯材の表面に酸化錫の被覆層が形成された導電性粒子を得た。
[Comparative Example 3]
Using the apparatus shown in FIG. 1, coated particles were produced according to the method described in Example 1 of JP-A-2005-108734. Into the mother liquor, 3510 cm 3 of pure water is added, and then 200 g of a spherical barium sulfate core material having an average particle diameter D 50 of 0.15 μm is added and dispersed until the coarse particles of barium sulfate disappear. Generated. To the slurry, 576 g of sodium stannate was added and dissolved. The Sn concentration in the slurry was 41%. The slurry was neutralized by adding 20% sulfuric acid until the pH of the slurry was 2.5. Simultaneously with the start of neutralization in the mother liquor, the first pump, homogenizer, and second pump are sequentially activated to send the slurry in the mother liquor to the homogenizer for strong dispersion treatment, and the slurry after strong dispersion treatment is reacted. Returned to the tank. The homogenizer was stirred at 4500 rpm. The strong dispersion treatment was continued for 98 minutes from the start to the end of neutralization. In this way, particles having a tin hydroxide coating layer formed on the surface of the barium sulfate core material were obtained. Thereafter, in the same manner as in Example 4, conductive particles in which a tin oxide coating layer was formed on the surface of the barium sulfate core material were obtained.
〔比較例４〕
母液槽中にホモジナイザ（ＩＫＡジャパン製 Ｔ−５０）を取り付けた装置を用い、水酸化錫で被覆された粒子を製造した。母液槽中に純水３５１０ｃｍ3を投入し、次に平均粒径Ｄ50が０．１５μｍである球状の硫酸バリウム芯材２００ｇを投入して硫酸バリウムの粗粒がなくなるまでホモジナイザで強分散処理させてスラリーを生成した。ホモジナイザを用いて強分散処理しながら該スラリーに錫酸ナトリウム５７６ｇを投入し、これを溶解させた。スラリー中のＳｎ濃度は４１％であった。次にホモジナイザにて強分散処理しながら該スラリーに２０％硫酸をスラリーのｐＨが２．５になるまで添加して中和した。中和を開始してから終了するまで９８分間にわたり強分散処理を行い続けた。この間、ホモジナイザは４５００ｒｐｍで攪拌させた。このようにして硫酸バリウム芯材の表面に水酸化錫の被覆層が形成された粒子を得た。その後は実施例４と同様にして、硫酸バリウム芯材の表面に酸化錫の被覆層が形成された導電性粒子を得た。
[Comparative Example 4]
Using a device equipped with a homogenizer (T-50 manufactured by IKA Japan) in a mother liquor, particles coated with tin hydroxide were produced. 3510 cm 3 of pure water is introduced into the mother liquor, and then 200 g of a spherical barium sulfate core material having an average particle diameter D 50 of 0.15 μm is introduced and subjected to a strong dispersion treatment with a homogenizer until the coarse particles of barium sulfate disappear. A slurry was produced. While being strongly dispersed using a homogenizer, 576 g of sodium stannate was added to the slurry and dissolved. The Sn concentration in the slurry was 41%. Next, 20% sulfuric acid was added to the slurry while strongly dispersing with a homogenizer until the pH of the slurry became 2.5, and neutralized. The strong dispersion treatment was continued for 98 minutes from the start to the end of neutralization. During this time, the homogenizer was stirred at 4500 rpm. In this manner, particles having a tin hydroxide coating layer formed on the surface of the barium sulfate core material were obtained. Thereafter, in the same manner as in Example 4, conductive particles in which a tin oxide coating layer was formed on the surface of the barium sulfate core material were obtained.
〔評価〕
実施例及び比較例について、反応後でかつ洗浄前の粒子について、粒度分布（Ｄ50、Ｄ90）を以下の方法で測定した。また、焼成後の導電性粒子についても、粒度分布（Ｄ50、Ｄ90）を測定した。更に焼成後の導電性粒子について、比表面積及び体積抵抗を以下の方法で測定した。それらの結果を以下の表２に示す。
[Evaluation]
For Examples and Comparative Examples, the reaction after the and before washing the particles, the particle size distribution (D 50, D 90) were measured by the following method. As for the conductive particles after firing was measured particle size distribution (D 50, D 90). Furthermore, the specific surface area and volume resistance of the conductive particles after firing were measured by the following methods. The results are shown in Table 2 below.
〔粒度分布の測定〕
２００ｃｍ3のサンプル容器に試料約０．１ｇを採り、これに０．２ｇ／ｌのヘキサメタリン酸ソーダを１０ｃｍ3添加混合し、引き続き純水９０ｃｍ3を添加した。日本精機株式会社製の超音波分散機であるＵＳ−３００Ｔを用いて試料を１０分間分散しサンプル液を調製した。このサンプル液を用い、日機装株式会社製マイクロトラックＨＲＡを用いて分散粒度Ｄ50及びＤ90を測定した。
(Measurement of particle size distribution)
About 0.1 g of a sample was placed in a 200 cm 3 sample container, and 10 cm 3 of 0.2 g / l sodium hexametaphosphate was added and mixed thereto, followed by addition of 90 cm 3 of pure water. A sample solution was prepared by dispersing the sample for 10 minutes using US-300T, an ultrasonic disperser manufactured by Nippon Seiki Co., Ltd. Using this sample solution, the dispersed particle sizes D 50 and D 90 were measured using Microtrac HRA manufactured by Nikkiso Co., Ltd.
〔比表面積の測定〕
ユアサアイオニクス株式会社製モノソーブを用い、ＢＥＴ比表面積を測定した。
[Measurement of specific surface area]
The BET specific surface area was measured using a monosorb manufactured by Yuasa Ionics Co., Ltd.
〔体積抵抗率の測定〕
三菱化学株式会社製ロレスタＰＡＰＤ−４１を用い、試料を５００ｋｇｆ／ｃｍ2に加圧した状態下に、同社製ロレスタＡＰを用い体積抵抗率を測定した。
(Measurement of volume resistivity)
Using a Loresta PAPD-41 manufactured by Mitsubishi Chemical Corporation, the volume resistivity was measured using Loresta AP manufactured by the same company under the condition that the sample was pressurized to 500 kgf / cm 2 .
表２に示す結果から明らかなように、実施例で得られた粒子は、粒度分布がシャープであり、粒子の凝集の程度が低いことが判る。また、体積抵抗が低く、粒子の分散性が良好であることが判る。 As is apparent from the results shown in Table 2, the particles obtained in the examples have a sharp particle size distribution and a low degree of particle aggregation. Moreover, it turns out that volume resistance is low and the dispersibility of particle | grains is favorable.
また、図４と図５との比較から明らかなように、実施例３の導電性粒子（図４）においては、酸化錫の一次粒子の凝集の程度が低く、芯材粒子である酸化チタンの表面に緻密に付着していることが判る。これに対して、比較例１の導電性粒子（図５）においては、酸化錫の一次粒子の凝集の程度が甚だしく、それに起因して芯材粒子である酸化チタンの表面に粗く付着しており、凝集した粒子間に多くの空隙を有していることが判る。 Further, as is clear from the comparison between FIG. 4 and FIG. 5, in the conductive particles of Example 3 (FIG. 4), the degree of aggregation of the primary particles of tin oxide is low, and the titanium oxide as the core material particles It can be seen that it is closely attached to the surface. On the other hand, in the conductive particles of Comparative Example 1 (FIG. 5), the degree of aggregation of the primary particles of tin oxide is significant, and as a result, the particles are roughly adhered to the surface of titanium oxide that is the core particle. It can be seen that there are many voids between the aggregated particles.
更に、実施例１〜６と実施例７〜１４との対比から明らかなように、芯材粒子を予め分散処理に付し、その後に被覆層を形成すると、焼成前の粒子はそのＤ50／Ｄ90の値が大きくなり、シャープな粒度分布を有していることが判る。 Further, as is clear from the comparison between Examples 1 to 6 and Examples 7 to 14, when the core particles are preliminarily subjected to a dispersion treatment and then a coating layer is formed, the particles before firing are D 50 / D 90 of greater, it is found to have a sharp particle size distribution.
１０ 製造装置
１１ 母液槽
１２ 第１循環配管
１３ 強分散装置
１４ 第２循環配管
２０ 母液
DESCRIPTION OF SYMBOLS 10 Manufacturing apparatus 11 Mother liquor tank 12 1st circulation piping 13 Strong dispersion apparatus 14 2nd circulation piping 20 Mother liquid
Claims (7)
該強分散装置において該母液を強分散させた状態下に該母液と該反応物とを反応させて、該芯材粒子の表面に被覆層を形成する、被覆層を有する粒子の製造方法であって、
前記芯材粒子は、そのＤ ５０ が０．０１〜１００μｍであり、
前記被覆層形成用の反応物が酸又はアルカリであり、
前記強分散装置がホモジナイザであり、
前記強分散装置の容積Ｖ２が１０〜５００ｃｍ ３ であり、
前記強分散装置に供給される前記反応物の速度Ｓ３と該強分散装置に流入する前記母液の流速Ｓ１との比Ｓ３／Ｓ１が０．０１〜０．０５であり、
前記被覆層を有する粒子が、Ｄ ５０ ／Ｄ ９０ の値が０．５〜１である導電性粒子である、被覆層を有する粒子の製造方法。 While circulating the mother liquor in which the core material particles are dispersed in the medium, the reactant for forming the coating layer is supplied to the strong dispersion device provided in a part of the circulation path,
Reacting the mother liquor and the reaction under conditions where the mother liquor obtained by the strongly dispersed in said strong dispersion device, it forms a coating layer on the surface of the core material particles, in the manufacturing method of the particles having a coating layer There,
The core particles, the D 50 is 0.01 to 100 [mu] m,
The reaction product for forming the coating layer is an acid or an alkali,
The strong dispersion device is a homogenizer;
The volume V2 of the strong dispersion device is 10 to 500 cm 3 ,
The ratio S3 / S1 of the reactant flow rate S3 supplied to the strong dispersion device and the flow rate S1 of the mother liquor flowing into the strong dispersion device is 0.01 to 0.05,
It said particles having a coating layer, the value of D 50 / D 90 is electrically conductive particles is 0.5 to 1, the production method of the particles having a coating layer.
前記母液中に１）水溶性錫化合物、２）水溶性亜鉛化合物、又は３）水溶性インジウム化合物及び水溶性錫化合物が含まれている請求項１ないし４の何れかに記載の製造方法。 The core particles are made of titanium dioxide, barium sulfate, alumina or silicon dioxide;
The mother liquor 1) a water-soluble tin compound in, 2) a water-soluble zinc compound, or 3) The method according to any one of claims 1 to 4 water-soluble indium compound and a water-soluble tin compound is contained.
粒度分布Ｄ50／Ｄ90の値が０．５〜１であり、
前記芯材粒子が水に分散してなり、水溶性錫化合物を含む母液を循環させつつ、循環経路の一部に設けられた強分散装置に酸又はアルカリを供給し、
該強分散装置において該母液を強分散させた状態下に該母液と該酸又はアルカリとを中和反応させて、該芯材粒子の表面に錫の水酸化物からなる被覆層を形成し、
錫の水酸化物からなる前記被覆層が形成された粒子を分離して、洗浄及び乾燥させた後に焼成することで得られたものである、導電性粒子。
Conductive particles having a coating layer of conductive tin oxide on the surface of core particles made of titanium dioxide, barium sulfate, alumina, or silicon dioxide,
The particle size distribution D 50 / D 90 has a value of 0.5 to 1,
The core particles are dispersed in water , and while circulating a mother liquor containing a water-soluble tin compound, supplying acid or alkali to a strong dispersion device provided in a part of the circulation path,
The mother liquor under a state of being strongly disperse the mother liquor in the said strong dispersing device and the acid or alkali by neutralization reaction to form a coating layer made of tin hydroxide on the surface of the core material particles,
Conductive particles obtained by separating the particles on which the coating layer made of a hydroxide of tin is formed, washing and drying the particles, and firing the particles.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2008317614A JP5438956B2 (en) | 2008-03-18 | 2008-12-12 | Method for producing particles having coating layer |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2008070028 | 2008-03-18 | ||
| JP2008070028 | 2008-03-18 | ||
| JP2008317614A JP5438956B2 (en) | 2008-03-18 | 2008-12-12 | Method for producing particles having coating layer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2009255042A JP2009255042A (en) | 2009-11-05 |
| JP5438956B2 true JP5438956B2 (en) | 2014-03-12 |
Family
ID=41383171
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2008317614A Expired - Fee Related JP5438956B2 (en) | 2008-03-18 | 2008-12-12 | Method for producing particles having coating layer |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP5438956B2 (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2871209B1 (en) * | 2012-07-06 | 2018-09-12 | Sakai Chemical Industry Co., Ltd. | Barium sulfate composite particles, resin composition containing same, and process for producing same |
| JP6071360B2 (en) * | 2012-09-14 | 2017-02-01 | 三井金属鉱業株式会社 | Conductive particles |
| JP6102404B2 (en) * | 2013-03-27 | 2017-03-29 | ライト工業株式会社 | Method and equipment for producing silica sol grout |
| JP6249723B2 (en) * | 2013-11-07 | 2017-12-20 | 三井金属鉱業株式会社 | Conductive particles and method for producing the same |
| JP6753280B2 (en) | 2016-11-24 | 2020-09-09 | コニカミノルタ株式会社 | Electrophotographic photosensitive member |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2959927B2 (en) * | 1993-05-27 | 1999-10-06 | チタン工業株式会社 | White conductive powder and method for producing the same |
| US6268054B1 (en) * | 1997-02-18 | 2001-07-31 | Cabot Corporation | Dispersible, metal oxide-coated, barium titanate materials |
| JPH11202434A (en) * | 1998-01-08 | 1999-07-30 | Konica Corp | Apparatus for producing silver halide emulsion and production therefor |
| JP4614023B2 (en) * | 1999-06-14 | 2011-01-19 | Ｄｉｃ株式会社 | Pigment dispersing apparatus and pigment dispersing method |
| JP4540091B2 (en) * | 2003-09-30 | 2010-09-08 | 三井金属鉱業株式会社 | Conductive powder and method for producing the same |
| JP4421323B2 (en) * | 2004-02-23 | 2010-02-24 | Ｎｅｃトーキン株式会社 | Ferrite coated particulate manufacturing equipment |
| JP4722412B2 (en) * | 2004-05-21 | 2011-07-13 | 三井金属鉱業株式会社 | Conductive tin oxide powder, method for producing the same, conductive paste and conductive paint |
| JP5192643B2 (en) * | 2005-11-14 | 2013-05-08 | 三井金属鉱業株式会社 | Conductive zinc oxide coated powder and method for producing the same |
| JP2007191789A (en) * | 2005-12-19 | 2007-08-02 | Fujifilm Corp | Core/shell particle and method for producing the same |
-
2008
- 2008-12-12 JP JP2008317614A patent/JP5438956B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JP2009255042A (en) | 2009-11-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5155840B2 (en) | Method for producing metal hydroxide particles | |
| JP5438956B2 (en) | Method for producing particles having coating layer | |
| KR101510369B1 (en) | Process for producing copper powder and copper powder | |
| JP2022116130A (en) | Method for manufacturing silver-coated copper nanowire having core-shell structure by using chemical reduction method | |
| TWI518038B (en) | Flaky silver powder, conductive paste composition and producing method for flaky silver powder | |
| WO2007111231A1 (en) | Process for production of copper powder and copper powder obtained by the process | |
| EP2848588A1 (en) | Antimony-doped tin oxide, infrared-ray-absorbable pigment, infrared-ray-absorbable ink, printed matter, and method for producing antimony-doped tin oxide | |
| KR20100024431A (en) | Spherical copper fine powder and process for production of the same | |
| CN103754914A (en) | Preparation method for submicron active calcium carbonate special for PVC and with low oil absorption value | |
| JP5510531B1 (en) | Silver powder and silver paste | |
| CN112605394A (en) | Preparation method of silver powder for conductive paste | |
| WO2004058645A1 (en) | Electroconductive zinc oxide powder and method for production thereof, and electroconductive composition | |
| JP4540091B2 (en) | Conductive powder and method for producing the same | |
| KR101121384B1 (en) | Method for production of electroconductive tin oxide powder | |
| JP6252275B2 (en) | Silver powder and method for producing the same | |
| JP6071360B2 (en) | Conductive particles | |
| JP2003342621A (en) | Method for manufacturing copper powder and copper powder obtained thereby | |
| JP2015228352A (en) | Conductive particle | |
| US8048932B2 (en) | Fabrication method of CaCO3 nanoparticles using beads milling | |
| JP4722412B2 (en) | Conductive tin oxide powder, method for producing the same, conductive paste and conductive paint | |
| JP5500237B1 (en) | Silver powder | |
| JPH083605A (en) | Production of monodispersive noble metal powder and the same noble metal powder | |
| JP2017506677A (en) | Method for surface coating inorganic particles, in particular titanium dioxide pigment particles | |
| JP2006131978A (en) | SPHERICAL NiP FINE PARTICLE, METHOD FOR PRODUCING THE SAME AND ELECTRICALLY CONDUCTIVE PARTICLE FOR ANISOTROPIC ELECTRICALLY CONDUCTIVE FILM | |
| JP2011137189A (en) | Silver particulate having high sphericity, and method for producing the same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20110927 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20120829 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20120904 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20121102 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20130827 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20131028 |
|
| 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: 20131119 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20131216 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 5438956 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| LAPS | Cancellation because of no payment of annual fees |