JP3268020B2 - Method for producing silicon nitride powder - Google Patents
Method for producing silicon nitride powderInfo
- Publication number
- JP3268020B2 JP3268020B2 JP22303692A JP22303692A JP3268020B2 JP 3268020 B2 JP3268020 B2 JP 3268020B2 JP 22303692 A JP22303692 A JP 22303692A JP 22303692 A JP22303692 A JP 22303692A JP 3268020 B2 JP3268020 B2 JP 3268020B2
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- Prior art keywords
- silicon nitride
- nitride powder
- particle size
- average particle
- sintered body
- Prior art date
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Description
【0001】[0001]
【産業上の利用分野】本発明は、高強度(室温曲げ強度
870MPa以上)、高靭性(IF法破壊靱性値8.3
MPam 1/2 以上)かつ高信頼性(ワイブル係数33以
上)の焼結体を製造することができる窒化珪素粉末の製
造方法に関する。BACKGROUND OF THE INVENTION The present invention relates to a high strength (room temperature bending strength)
870 MPa or higher) , high toughness (IF method fracture toughness value 8.3)
MPam 1/2 or more) and high reliability (Weibull coefficient 33 or less)
Made in silicon nitride powder capable of producing a sintered body above)
Construction method .
【0002】[0002]
【従来の技術】窒化珪素焼結体は、強度、硬度、靭性、
耐熱性、耐蝕性、耐熱衝撃性等に優れた材料であること
から、各種産業機構部品、自動車部品、ガスタービン部
品等の利用が進められている。2. Description of the Related Art Sintered silicon nitride has strength, hardness, toughness,
Since it is a material excellent in heat resistance, corrosion resistance, thermal shock resistance, and the like, various industrial mechanism parts, automobile parts, gas turbine parts, and the like are being used.
【0003】窒化珪素粉末の製造方法としては、金属珪
素直接窒化法、シリカ還元法、ハロゲン化珪素法が工業
化されている。これらの製法で得られた粉末は、それぞ
れ異なった粉体特性を有し、焼結性と焼結体特性に大き
く影響している。一般的には、高比表面積、高α相含有
率、高純度で粒度分布のシャープなものがよいとされて
おり、このような観点にたって従来より盛んに研究が行
われている。As methods for producing silicon nitride powder, a metal silicon direct nitriding method, a silica reduction method, and a silicon halide method have been industrialized. The powders obtained by these production methods have different powder characteristics, and greatly affect the sinterability and the characteristics of the sintered body. In general, it is considered that a material having a high specific surface area, a high α-phase content, a high purity and a sharp particle size distribution is preferable.
【0004】しかしながら、β型窒化珪素粉末について
は、低純度で粗粒品しか市販されていない。粒度分布の
面から検討を加えた先行技術として、特開平02−25
5573号公報には、平均粒径1.5μmの窒化珪素粉
末と、平均粒径2.5〜5μmの窒化珪素粉末とを重量
比で95:5〜75:25の割合で混合すると、破壊靱
性値が最大8.1MN/m 3/2 であるものは室温曲げ強
度630MPa(第2表No2)で、室温曲げ強度が最
大720MPaであるものは破壊靱性値が6.2MN/
m 3/2 (第1表No3)の焼結体となることが記載され
ているが、強度靭性及び信頼性の全てにおいて高度にバ
ランスさせた焼結体は製造されていない。However, for the β-type silicon nitride powder, it has not been only coarse products marketed in low purity. Particle size distribution
Japanese Patent Application Laid-Open No.
No. 5573 discloses a silicon nitride powder having an average particle size of 1.5 μm.
Powder and silicon nitride powder having an average particle size of 2.5 to 5 μm.
When mixed at a ratio of 95: 5 to 75:25, the fracture toughness
Those with properties of up to 8.1 MN / m 3/2 have room temperature flexural strength
Temperature of 630 MPa (Table 2, No. 2)
Those having a large 720 MPa have a fracture toughness value of 6.2 MN /
m 3/2 (Table 1, No. 3).
However, a sintered body highly balanced in all of the strength toughness and reliability has not been manufactured.
【0005】[0005]
【発明が解決しようとする課題】本発明の目的は、β型
窒化珪素粉末の粒度特性を厳格に規定することによっ
て、高強度(室温曲げ強度870MPa以上)、高靭性
(IF法破壊靱性値8.3MPam 1/2 以上)かつ高信
頼性(ワイブル係数33以上)の焼結体を製造すること
ができる窒化珪素粉末の製造方法を提供することにあ
る。SUMMARY OF THE INVENTION An object of the present invention is to provide a high strength (room temperature bending strength of 870 MPa or more) and high toughness by strictly regulating the particle size characteristics of β-type silicon nitride powder .
(IF fracture toughness value of 8.3 MPam 1/2 or more) and Takanobu
Manufacture of sintered bodies with high reliability (Weibull coefficient of 33 or more)
To provide a method for producing a silicon nitride powder .
【0006】[0006]
【課題を解決するための手段】すなわち、本発明は、β
相含有率が82%以上で平均粒径Daが5μm以下であ
る窒化珪素粉末Aと、β相含有率が82%以上で平均粒
径Dbが5.5〜24.0μmである窒化珪素粉末Bと
を、A/Bの重量比が50〜300で、Db/Daが
9.2〜48.0となるように混合することを特徴とす
る、高強度(室温曲げ強度870MPa以上)、高靭性
(IF法破壊靱性値8.3MPam 1/2 以上)かつ高信
頼性(ワイブル係数33以上)の焼結体を製造すること
ができる窒化珪素粉末の製造方法である。That is, the present invention provides a β
Silicon nitride powder A having a phase content of 82% or more and an average particle size Da of 5 μm or less, and a silicon nitride powder having a β phase content of 82% or more and an average particle size Db of 5.5 to 24.0 μm B and A / B in a weight ratio of 50 to 300 and Db / Da
It is characterized by being mixed so as to be 9.2 to 48.0.
High strength (room temperature bending strength of 870 MPa or more), high toughness
(IF fracture toughness value of 8.3 MPam 1/2 or more) and Takanobu
Manufacture of sintered bodies with high reliability (Weibull coefficient of 33 or more)
This is a method for producing a silicon nitride powder .
【0007】以下、さらに詳しく本発明について説明す
る。Hereinafter, the present invention will be described in more detail.
【0008】まず、本発明で使用される窒化珪素粉末A
及び窒化珪素粉末Bのいずれもは、α相の割合が18%
未満でβ相の割合が82%以上であることが必要であ
る。α相の割合が18%以上であると、α相の粒界にお
いて溶解析出反応が起こり、β相に相転移する際の柱状
晶の成長が活発になりすぎて、焼結体の強度が低下した
りばらついたりする。これまでに、α相からβ相への転
移反応によってアスペクト比の高いβ粒子が得られ、そ
れによって高強度かつ高靭性の焼結体が得られたのは、
このβ粒子の粒成長を制御できたからであると考えられ
ているが、この制御は非常に困難であった。First, the silicon nitride powder A used in the present invention
And silicon nitride powder B both have an α phase ratio of 18%.
And the proportion of β phase must be 82% or more . If the proportion of the α phase is 18% or more, a solution precipitation reaction occurs at the grain boundary of the α phase, and the growth of columnar crystals during the phase transition to the β phase becomes too active, and the strength of the sintered body decreases. Do and scatter. So far, β particles with a high aspect ratio have been obtained by the transition reaction from the α phase to the β phase, and as a result, a sintered body with high strength and high toughness has been obtained.
It is thought that this was because the grain growth of the β particles could be controlled, but this control was very difficult.
【0009】本発明では、このような制御の困難さをな
くするために、窒化珪素粉末のβ相の割合を82%以上
としたものである。本発明のような窒化珪素粉末を用い
ると、α相の粒界における溶解析出反応がなくなり、原
料窒化珪素粉末の粒度分布に沿った焼結体組織となるの
で、原料の粒度分布を制御することにより、強度、靭性
等のばらつきの少ない均質な焼結体となる。また、従来
のα相含有率の高い窒化珪素粉末を製造するには、精密
な温度調節と長時間の反応が必要となるので、本発明の
窒化珪素粉末に比べて製造コストが高いものであった。In the present invention, in order to eliminate such difficulties in controlling, the ratio of the β phase of the silicon nitride powder is set to 82% or more. When a silicon nitride powder as in the present invention is used, the dissolution and precipitation reaction at the grain boundary of the α phase is eliminated, and a sintered body structure follows the particle size distribution of the raw material silicon nitride powder. Thereby, a homogeneous sintered body with little variation in strength, toughness, etc. can be obtained. In addition, the production of silicon nitride powder having a high α-phase content requires precise temperature control and a long-time reaction, so that the production cost is higher than that of the silicon nitride powder of the present invention. Was.
【0010】本発明において、β相含有率は、X線回折
法における回折ピークの強度比から次式によって求める
ことができる。 β相含有率(%)={(Iβ101+Iβ210)/(Iα102+Iα201 +Iβ101+Iβ210)}×100 Iβ101:β窒化珪素の(101)面の回折ピーク強
度 Iβ210:β窒化珪素の(210)面の回折ピーク強
度 Iα102:α窒化珪素の(102)面の回折ピーク強
度 Iα201:α窒化珪素の(201)面の回折ピーク強
度In the present invention, the β phase content can be determined by the following equation from the intensity ratio of diffraction peaks in the X-ray diffraction method. β phase content (%) = {(Iβ101 + Iβ210) / (Iα102 + Iα201 + Iβ101 + Iβ210)} × 100 Iβ101: Diffraction peak intensity of (101) plane of β silicon nitride Iβ210: Diffraction peak intensity of (210) plane of β silicon nitride Iα102: Diffraction peak intensity of α silicon nitride on (102) plane Iα201: Diffraction peak intensity of α silicon nitride on (201) plane
【0011】本発明の大きな特徴は、窒化珪素粉末の粒
度構成を規定することである。一般に、窒化珪素焼結体
の強度と破壊靭性が、アルミナや炭化珪素のそれに比べ
て高いのは、窒化珪素焼結体の微構造が特異なβ柱状晶
からなっていることによるものである。このβ柱状晶の
サイズ、分布及びアスペクト比と焼結体特性との関係に
ついては、アスペクト比が大きく微細であるほど高強度
であり、また、粗大なβ柱状晶が焼結体組織に均一に分
布しているほど破壊靭性が高くなる傾向がある。A major feature of the present invention is to define the particle size composition of the silicon nitride powder. In general, the strength and fracture toughness of a silicon nitride sintered body are higher than those of alumina and silicon carbide because the microstructure of the silicon nitride sintered body is composed of a unique β columnar crystal. Regarding the relationship between the size, distribution and aspect ratio of the β columnar crystals and the characteristics of the sintered body, the higher the aspect ratio and the finer the finer, the higher the strength, and the coarser β columnar crystals are uniformly distributed in the structure of the sintered body. The more they are distributed, the higher the fracture toughness tends to be.
【0012】本発明は、β相含有率82%以上の窒化珪
素粉末を原料とし、その粒度分布を以下のように規定す
ることによって、焼結体の微構造を制御し焼結体特性を
向上させたものである。The present invention controls the microstructure of a sintered body and improves the characteristics of the sintered body by using a silicon nitride powder having a β phase content of 82% or more as a raw material and defining the particle size distribution as follows. It was made.
【0013】すなわち、平均粒径Daが5μm以下でβ
相含有率82%以上の窒化珪素粉末Aと平均粒径Dbが
5.5〜24.0μmでβ相含有率82%以上の窒化珪
素粉末Bとを、A/Bの重量比が50〜300で、Db
/Daが9.2〜48.0となるように混合したもので
ある。That is, when the average particle diameter Da is 5 μm or less, β
Silicon nitride powder A having a phase content of 82 % or more and average particle diameter Db
A silicon nitride powder B having a β-phase content of 82 % or more at 5.5 to 24.0 μm is mixed with Db at a weight ratio of A / B of 50 to 300 .
/ Da is 9.2 to 48.0 .
【0014】本発明で使用される窒化珪素粉末Aの平均
粒径Daを5μm以下に限定したのは、β相の多い窒化
珪素粉末はα相の多いそれに比べて緻密化しやすい傾向
にあるが、平均粒径Daが5μmをこえると緻密化度が
低下するからである。平均粒径Daの下限については特
に制限はなく、極端にカサ高となって成形ができなくな
らなければよい。The reason why the average particle diameter Da of the silicon nitride powder A used in the present invention is limited to 5 μm or less is that silicon nitride powder having a large β phase tends to be more dense than that having a large α phase. This is because when the average particle diameter Da exceeds 5 μm, the degree of densification decreases. There is no particular limitation on the lower limit of the average particle diameter Da, as long as the bulk becomes extremely high so that molding cannot be performed.
【0015】一方、本発明で使用される窒化珪素粉末B
の平均粒径Dbは5.5〜24.0μmである。5.5
μm未満では、焼結体中のβ柱状晶のサイズが微細にな
りすぎて破壊靭性の向上が認められなくなり、また、2
4μmをこえると、焼結障害を起こして緻密化度が低下
するとともに、焼結体に欠陥が存在し強度が低下したり
ばらついたりするようになる。On the other hand, the silicon nitride powder B used in the present invention
Has an average particle size Db of 5.5 to 24.0 μm. 5.5
is less than [mu] m, the size of β columnar crystals in the sintered body is not observed improvement in fracture toughness too fine, also 2
If the thickness exceeds 4 μm, sintering failure occurs, the degree of densification is reduced, and defects are present in the sintered body, and the strength is reduced or varied.
【0016】本発明において、窒化珪素粉末A/窒化珪
素粉末Bの重量比が、50未満では、窒化珪素粉末の粗
粒が多くなり過ぎて焼結体組織が粗いβ柱状晶となり、
強度特性が低下する。一方、該比が300をこえると、
逆に粗粒の窒化珪素粉末が少なくなってβ柱状晶が不足
し、破壊靭性の向上がなくなる。In the present invention, if the weight ratio of the silicon nitride powder A / silicon nitride powder B is less than 50 , the coarse grains of the silicon nitride powder become too large and the sintered body structure becomes a coarse β columnar crystal,
The strength characteristics decrease. On the other hand, when the ratio exceeds 300 ,
Conversely, the amount of coarse silicon nitride powder decreases and β columnar crystals become insufficient, and improvement in fracture toughness is lost.
【0017】また、平均粒径の比Db/Daが9.2未
満では、得られた焼結体のβ柱状晶のサイズの分布幅が
小さくなって破壊靭性が向上しなくなり、一方、48.
0をこえると、逆にその分布幅が広くなり過ぎて異常に
成長したβ柱状晶が欠陥となって強度特性が低下した
り、ばらついたりしたりするようになる。If the ratio Db / Da of the average particle size is less than 9.2 , the distribution width of the size of β columnar crystals in the obtained sintered body becomes small, and the fracture toughness is not improved .
If it exceeds 0 , on the contrary, the distribution width becomes too wide, and the abnormally grown β columnar crystal becomes a defect, resulting in a decrease in the strength characteristics or a variation.
【0018】本発明で使用される窒化珪素粉末Aと窒化
珪素粉末Bは、種々の方法で製造することができる。例
えば、金属珪素直接窒化法、シリカ還元法、ハロゲン化
珪素法により、β相含有率82%以上の窒化珪素を製造
し粉砕後分級することによって製造することができる。
金属珪素直接窒化法によってβ相含有率82%以上の窒
化珪素を製造するには、金属珪素粉末のカサ密度1.5
g/cm3 以下程度の成形体を窒素及び/又はアンモニ
アを含む雰囲気中、温度1300〜1500℃で加熱窒
化することによって容易に製造することができる。The silicon nitride powder A and the silicon nitride powder B used in the present invention can be produced by various methods. For example, it can be produced by producing silicon nitride having a β phase content of 82 % or more by a metal silicon direct nitriding method, a silica reduction method, or a silicon halide method, pulverizing and then classifying.
In order to produce silicon nitride having a β phase content of 82 % or more by the metal silicon direct nitriding method, the bulk density of the metal silicon powder is 1.5%.
It can be easily manufactured by heating and nitriding a molded body of about g / cm 3 or less at a temperature of 1300 to 1500 ° C. in an atmosphere containing nitrogen and / or ammonia.
【0019】[0019]
【実施例】以下、実施例と比較例をあげてさらに具体的
に本発明を説明する。The present invention will be described below more specifically with reference to examples and comparative examples.
【0020】実施例1〜3 比較例1〜17 比表面積2m2 /gの金属珪素粉末をカサ密度1g/c
m3 の100×100×25mmの成形体に成形した。
それを電気炉に入れ、窒素雰囲気中、窒化温度を120
0〜1500℃の範囲で種々変化させてβ相含有率の異
なる窒化珪素を製造した。Examples 1 to 3 Comparative Examples 1 to 17 Metallic silicon powder having a specific surface area of 2 m 2 / g was applied with a bulk density of 1 g / c.
It was molded into a molded body of 100 × 100 × 25 mm of m 3 .
Put it in an electric furnace and set the nitriding temperature to 120 in a nitrogen atmosphere.
Silicon nitrides having different β-phase contents were produced with various changes in the range of 0 to 1500 ° C.
【0021】得られた窒化珪素インゴットを粗砕・中砕
後さらに乾式粉砕と湿式粉砕を行い精製して、表1に示
すように、種々のβ相含有率、平均粒径DaとDbを有
する窒化珪素粉末Aと窒化珪素粉末Bを製造した。The obtained silicon nitride ingot is refined by coarse pulverization and medium pulverization, followed by dry pulverization and wet pulverization, and has various β phase contents and various average particle diameters Da and Db as shown in Table 1. Silicon nitride powder A and silicon nitride powder B were produced.
【0022】乾式粉砕は、アルミナ製ボールを用いたボ
ールミルにより、また、湿式粉砕は鉄製ボールを用い水
を媒体として行った。精製は、塩酸とフッ酸溶液により
行った。Dry pulverization was performed by a ball mill using alumina balls, and wet pulverization was performed using iron balls using water as a medium. Purification was performed using a hydrochloric acid and hydrofluoric acid solution.
【0023】窒化珪素粉末Aと窒化珪素粉末Bとを表1
の割合で配合し、窒化珪素製ボールを用いたボールミル
により乾式混合を行い混合粉末を調整した。Table 1 shows silicon nitride powder A and silicon nitride powder B.
And dry-blended by a ball mill using silicon nitride balls to prepare a mixed powder.
【0024】[0024]
【表1】 [Table 1]
【0025】得られた窒化珪素の混合粉末92重量部、
平均粒径1.5μmのY2O3粉末5重量部及び平均粒径
0.8μmのAl2O3粉末3重量部を配合し、1,1,
1−トリクロロエタン中で4時間ボールミルで湿式粉砕
し乾燥した後、圧力100kg/cm2 で6×10×6
0mmの成形体を成形し、それを圧力2700kg/c
m2 でCIP成形した。92 parts by weight of the obtained mixed powder of silicon nitride,
5 parts by weight of Y 2 O 3 powder having an average particle size of 1.5 μm and 3 parts by weight of Al 2 O 3 powder having an average particle size of 0.8 μm
After wet grinding in a ball mill for 4 hours in 1-trichloroethane and drying, 6 × 10 × 6 at a pressure of 100 kg / cm 2.
A molded body of 0 mm is formed and the pressure is 2700 kg / c.
CIP molding was performed at m 2 .
【0026】このCIP成形体をカーボンルツボにセッ
トし、圧力10kg/cm2 の窒素ガス雰囲気中、温度
1900℃で4時間焼成して焼結体を製造した。それを
3×4×40mmに研削加工し、相対密度、破壊靭性、
室温における4点曲げ強度及びn=30におけるワイブ
ル係数を測定した。それらの結果を表2に示す。The CIP compact was set in a carbon crucible and fired in a nitrogen gas atmosphere at a pressure of 10 kg / cm 2 at a temperature of 1900 ° C. for 4 hours to produce a sintered compact. Grind it to 3 × 4 × 40mm, and obtain relative density, fracture toughness,
The four-point bending strength at room temperature and the Weibull coefficient at n = 30 were measured. Table 2 shows the results.
【0027】なお、測定は以下の方法によった。 (1)平均粒径:粒度分布計(レーザ回折法、N&L社
製マイクロトラックSPA)による。 (2)相対密度:アルキメデス法による。 (3)破壊靭性:IF法による。 (4)曲げ強度:島津製作所社製「オートグラフAG−
2000A」による。The measurement was carried out according to the following method. (1) Average particle size: Measured with a particle size distribution analyzer (laser diffraction method, Microtrack SPA manufactured by N & L). (2) Relative density: by Archimedes' method. (3) Fracture toughness: by the IF method. (4) Flexural strength: "Autograph AG-" manufactured by Shimadzu Corporation
2000A ".
【0028】[0028]
【表2】 [Table 2]
【0029】[0029]
【発明の効果】本発明の窒化珪素粉末の製造方法によれ
ば、β型窒化珪素粉末にして、高強度(室温曲げ強度8
70MPa以上)、高靭性(IF法破壊靱性値8.3M
Pam 1/2 以上)かつ高信頼性(ワイブル係数33以
上)の焼結体を製造することができる窒化珪素粉末が提
供される。 According to the method for producing silicon nitride powder of the present invention,
For example, a β-type silicon nitride powder is used to obtain a high strength (bending strength at room temperature of 8).
70MPa or more), high toughness (IF method fracture toughness value 8.3M)
Pam 1/2 or more) and high reliability (Weibull coefficient 33 or less)
Silicon nitride powder that can produce the sintered body
Provided.
フロントページの続き (72)発明者 下平 博 福岡県大牟田市新開町1 電気化学工業 株式会社 大牟田工場内 審査官 大工原 大二 (56)参考文献 特開 平2−255573(JP,A) 特開 平6−9274(JP,A) 特開 昭62−297269(JP,A) 特開 平3−338833(JP,A) (58)調査した分野(Int.Cl.7,DB名) C01B 21/068 C04B 35/626 CA(STN)Continuation of the front page (72) Inventor Hiroshi Shimohira 1 Shinkai-cho, Omuta-shi, Fukuoka Prefecture Investigator in the Omuta Plant of Electric Chemical Industry Co., Ltd. 6-9274 (JP, A) JP-A-62-297269 (JP, A) JP-A-3-338833 (JP, A) (58) Fields investigated (Int. Cl. 7 , DB name) C01B 21/068 C04B 35/626 CA (STN)
Claims (1)
が5μm以下である窒化珪素粉末Aと、β相含有率が8
2%以上で平均粒径Dbが5.5〜24.0μmである
窒化珪素粉末Bとを、A/Bの重量比が50〜300
で、Db/Daが9.2〜48.0となるように混合す
ることを特徴とする、高強度(室温曲げ強度870MP
a以上)、高靭性(IF法破壊靱性値8.3MPam
1/2 以上)かつ高信頼性(ワイブル係数33以上)の焼
結体を製造することができる窒化珪素粉末の製造方法。 1. The β-phase content is82%With the above, the average particle diameter Da
Having a particle size of 5 μm or lessWhen,β phase content8
2%With the above, the average particle size Db is5.5 to 24.0μm
The weight ratio of A / B to silicon nitride powder B is50-300
And Db / Da isMix to make 9.2 to 48.0
High strength (Bending strength at room temperature 870MP)
a) or more, high toughness (IF method fracture toughness value 8.3MPam)
1/2 And high reliability (weibull coefficient of 33 or more)
A method for producing silicon nitride powder capable of producing a sintered body.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP22303692A JP3268020B2 (en) | 1992-08-21 | 1992-08-21 | Method for producing silicon nitride powder |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP22303692A JP3268020B2 (en) | 1992-08-21 | 1992-08-21 | Method for producing silicon nitride powder |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH0664906A JPH0664906A (en) | 1994-03-08 |
JP3268020B2 true JP3268020B2 (en) | 2002-03-25 |
Family
ID=16791840
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JP22303692A Expired - Fee Related JP3268020B2 (en) | 1992-08-21 | 1992-08-21 | Method for producing silicon nitride powder |
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JP (1) | JP3268020B2 (en) |
Families Citing this family (4)
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JP4744136B2 (en) * | 2004-12-22 | 2011-08-10 | ニプロパッチ株式会社 | Pilsicainide patch |
HRP20060381C1 (en) * | 2006-11-03 | 2017-08-11 | Jadran-Galenski Laboratorij D.D. | Cosmetic active composition comprising ingredients from sea |
JP5901448B2 (en) * | 2012-06-28 | 2016-04-13 | デンカ株式会社 | Silicon nitride powder for mold release agent |
WO2023210649A1 (en) * | 2022-04-27 | 2023-11-02 | 株式会社燃焼合成 | COLUMNAR PARTICLES OF β-SILICON NITRIDE, COMPOSITE PARTICLES, SINTERED SUBSTRATE FOR HEAT RADIATION, RESIN COMPOSITE, INORGANIC COMPOSITE, METHOD FOR PRODUCING COLUMNAR PARTICLES OF β-SILICON NITRIDE, AND METHOD FOR PRODUCING COMPOSITE PARTICLES |
-
1992
- 1992-08-21 JP JP22303692A patent/JP3268020B2/en not_active Expired - Fee Related
Also Published As
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JPH0664906A (en) | 1994-03-08 |
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