JPH03177364A - Method for removing additive in powder compact - Google Patents

Abstract

PURPOSE:To carry out degreasing without causing breakage or cracking by adding an additive to sinterable powder, forming the resultant mixture, coating the formed compact with an airtight resin film leaving part of the surface thereof, isostatically pressing the coated surface and heating the coated surface. CONSTITUTION:For example, a graphitic cellular substance 3 is placed on the inner wall of a pressure vessel 2 provided with a vent hole 1 and a powder compact 4 is then placed thereon. In the aforementioned state, a wet curing type urethane resin is applied to the surfaces of the powder compact 4, cellular substance 3 and inner wall surface of the vessel 2 with about 5mm width around the cellular substance 3 to carry out coating of a resin film 5. The vessel 2 is subsequently filled with glycerol from a nozzle 6 and the glycerol is then pressurized and held at ambient temperature by pump compression to drop the additive from the vent hole 1. The glycerol in the pressurized state is subsequently heated to heat the powder compact 3 and scatter the additive from the vent hole 1 into the air.

Description

【発明の詳細な説明】 〔産業上の利用分野〕 本発明は焼結性粉末成形体の製造方法に関する。[Detailed description of the invention] [Industrial application field] The present invention relates to a method for producing a sinterable powder compact.

より詳しくは、セラ５ツクス焼結体あるいは焼結合金を
得るために、セラミックス粉末あるいは金属粉末を射出
成形法あるいは鋳込み成形法で成形し、次に成形助剤と
して用いた添加剤を加熱・飛散させる方法に関する。More specifically, in order to obtain a ceramic sintered body or sintered alloy, ceramic powder or metal powder is molded by injection molding or cast molding, and then additives used as molding aids are heated and scattered. Concerning how to do so.

〔従来の技術〕[Conventional technology]

形状が複雑で、かつ量産されるセラミックス焼結体は、
原料であるアルミナ、ジルコニア、炭化ケイ素、窒化ケ
イ素、ムライトなどの粉末を、射出成形法または泥漿鋳
込み成形法によって所望する形状に成形し、脱脂後、つ
いでこの粉末成形体が焼結するに必要な温度に強熱する
ことにより工業的に生産されている。Ceramic sintered bodies with complex shapes and mass-produced are
Powders such as raw materials such as alumina, zirconia, silicon carbide, silicon nitride, and mullite are molded into a desired shape by injection molding or slurry casting, and after degreasing, the powder molded body is then molded with the necessary materials for sintering. It is produced industrially by ignition to high temperatures.

また、金属粉末を成形し次にこれを加熱して焼結合金を
得る方法、いわゆる粉末冶金法は、完成形状に近いもの
が１７られ、また金属ｍ織の制御が容易であるといった
優れた長所を持っており、Ｆｅ、　Ｎｉ、、Ｃｒ、、Ｔ
ｉ、、Ｃｏ５Ｓｎ、　Ｃｕなどの金属粉末を所定のεす
合に／Ｒ合し、成形助剤としての添加剤を加えて成形し
、脱脂後、ついでこの金属わ）末成形体がＶＰ：結する
に必要な温度に強熱することにより、工業的に生産され
ている。In addition, the so-called powder metallurgy method, which is a method of molding metal powder and then heating it to obtain a sintered alloy, has excellent advantages such as being able to produce a shape close to the finished shape and being easy to control the metal weave. , Fe, Ni, , Cr, , T
Metal powders such as i, Co5Sn, Cu, etc. are combined to a predetermined ε/R, an additive as a molding aid is added and molded, and after degreasing, this metal powder is then formed into a VP: bond. It is produced industrially by igniting it to the temperature required to produce it.

ここでいう射出成形法とは、上記したアルミナ、ジルコ
ニアなどのセラミックス粉末あるいはＦｅ、Ｎｉなどの
金属粉末と滌練されたとき、全体として可塑性を示し成
形し易くなるような、例えばポリスチレン、ポリエチレ
ン、ポリプロピレン、ジエチレンフタレート、パラフィ
ン、脂肪酸エステル、ポリビニルアルコールなどの熱可
塑性のある添加剤をセラミックスや金属のむ）末１００
重量部に対して１５〜３５重量部加えてぺ練し、この混
練物を所望する形状の金型に圧入して成形する方法であ
る。得られた粉末成形体は金型から取り出され、添加剤
を加熱により飛散・除去させた後、例えば１０００〜２
３００℃に強熱すれば所望する形状のセラミックス焼結
体あるいは焼結合金が得られる。The injection molding method here refers to materials such as polystyrene, polyethylene, etc. that exhibit plasticity as a whole and become easy to mold when mixed with ceramic powders such as alumina and zirconia, or metal powders such as Fe and Ni. Thermoplastic additives such as polypropylene, diethylene phthalate, paraffin, fatty acid esters, and polyvinyl alcohol are added to ceramics and metal powders.
This is a method in which 15 to 35 parts by weight are added and kneaded, and the kneaded product is press-fitted into a mold of a desired shape and molded. The obtained powder compact is taken out from the mold, and after scattering and removing the additives by heating,
By igniting to 300° C., a ceramic sintered body or sintered alloy of a desired shape can be obtained.

また、泥漿鋳込み成形法とは、アルミナなどの！５）未
１００重量部に対して、水または水とアルコールなどと
の混合物からなる添加剤３０〜５０重量部と少量のアク
リル系オリゴマー、ポリビニルアルコールなどの結合剤
や少量のＨＣＩ　、　ＡｌＣｌ：ｌ　、Ｎａ０１１、水
ガラスなどの解膠剤を添加してよく７昆合し、流動性が
あり、かつ粉末が沈殿しにくい安定な泥漿とし、この泥
漿を石膏のような多孔質からなる鋳型に流し込み、少な
くとも泥漿に含まれる添加剤を泥漿の流動性がなくなる
まで鋳型に吸収させたあと、鋳型より粉末成形体として
取り出す方法である。この方法で得られた粉末成形体に
は通常１０〜１５重量％の水などの添加剤が残存してい
るので、射出成形法の場合と同様に、この残存した添加
剤を加熱により飛散させたあと、同様に強熱すれば、所
望する形状の焼結体が得られる。In addition, the slurry casting method is suitable for alumina, etc. 5) To 100 parts by weight, add 30 to 50 parts by weight of an additive consisting of water or a mixture of water and alcohol, a small amount of an acrylic oligomer, a binder such as polyvinyl alcohol, and a small amount of HCI, AlCl:l, A peptizing agent such as Na011 and water glass is added to form a stable slurry that is fluid and does not easily cause powder to settle, and this slurry is poured into a mold made of porous material such as plaster. This is a method in which at least the additives contained in the slurry are absorbed into a mold until the slurry loses its fluidity, and then it is taken out of the mold as a powder compact. Since the powder compact obtained by this method usually contains 10 to 15% by weight of additives such as water, the remaining additives were dispersed by heating, as in the injection molding method. Then, by igniting it in the same way, a sintered body of the desired shape can be obtained.

なお、本発明においては、粉末を成形し強熱すれば緻密
な焼結体を得ることが可能なセラミックスおよび金属の
粉末を焼結性粉末と称することにし、これら焼結性粉末
の成形体を粉末成形体と称することにし、また、セラミ
ックス焼結体と焼結合金を総称して、焼結体と称するこ
とにする。更にまた、上記射出成形時あるいは鋳込成形
時に焼結性粉末を成形するために添加する成形助剤を総
称して添加剤と称することにし、わ）末成形体に含まれ
る添加剤を加熱により飛散させる操作を、該技術分野に
おける当業者の慣例用語に従い、以下「脱脂」と称する
。In the present invention, ceramic and metal powders that can be formed into dense sintered bodies by molding and igniting the powders are referred to as sinterable powders, and compacts of these sinterable powders are referred to as sinterable powders. This will be referred to as a powder compact, and the ceramic sintered body and sintered alloy will be collectively referred to as a sintered body. Furthermore, the forming aids added to mold the sinterable powder during injection molding or cast molding are collectively referred to as additives; The operation of scattering is hereinafter referred to as "degreasing" according to the common terminology of those skilled in the art.

しかしながら、上記の方法、すなわち射出成形法または
泥漿鋳込み成形法によって得られた粉末成形体を、脱脂
後強熱する方法によって得られた焼結体は、亀裂や表面
剥離など欠陥のある不良品（製品とはなし得ないもの）
が少なからず発生するという問題がある。However, sintered bodies obtained by the above method, that is, a method in which a powder compact obtained by injection molding or slurry casting is ignited after degreasing, are defective products with defects such as cracks and surface peeling. (Things that cannot be considered products)
There is a problem in that quite a few occur.

更に、これらの欠陥が焼結体内部に発生したものは、製
品化の段階で欠陥を発見することが困難なため一部はそ
のまま製品化されてしまい、使用中に破損し事故の原因
となるという大きな問題もある。Furthermore, if these defects occur inside the sintered body, it is difficult to detect the defects at the stage of product production, so some of the products end up being produced as is, causing damage during use and causing accidents. There is also a big problem.

しかしてここで特に指摘したいのは、上記亀裂や表面剥
離など欠陥はその殆どが脱脂工程において発生するとい
うことである。However, what I would like to particularly point out here is that most of the defects such as the cracks and surface peeling described above occur during the degreasing process.

即ち、粉末成形体に添加剤が残存していると、この粉末
成形体を強熱してセラミックス焼結体とする際に、該残
存添加剤が急激に気化し、この気化による膨張力のため
粉末成形体が爆裂するという問題が生じる。これを防止
する目的でわ〕末成形体は強熱に先立って脱脂工程を設
け、添加剤を除去しておくのである。That is, if additives remain in the powder compact, when the powder compact is ignited to form a ceramic sintered body, the remaining additives will rapidly vaporize, and the expansion force caused by this vaporization will cause the powder to collapse. The problem arises that the molded body explodes. In order to prevent this, the final compact is subjected to a degreasing process to remove the additives before being ignited.

しかしながら、粉末成形体は上述したように、泥漿鋳込
み成形法の場合でも１０重量％以上、射出成形法の場合
においては更に多くの、即ち１５重量％以上もの添加剤
を含んでいる。このように多量の添加剤を含んだ粉末成
形体から、割れや亀裂を発生させることなく、加熱によ
り添加剤を飛散・除去させることは、該加熱・飛散に伴
う該添加剤の大きな膨張力が、機械的強度の極めて低い
粉末成形体に強く作用するため、即ち、機械的強度の極
めて低い粉末成形体の内部の圧力の方が、粉末成形体の
外部の圧力よりも高くなるために、本質的に極めて難し
い問題なのである。However, as mentioned above, the powder compact contains 10% by weight or more of additives even in the case of the slurry casting method, and even more, ie, 15% by weight or more, in the case of the injection molding method. In order to scatter and remove additives from a powder compact containing a large amount of additives by heating without causing cracks or cracks, the large expansion force of the additives due to the heating and scattering is , because it acts strongly on powder compacts with extremely low mechanical strength, that is, the pressure inside the powder compact with extremely low mechanical strength is higher than the pressure outside the powder compact. This is an extremely difficult problem.

したがって、従来この工程は、大気圧あるいは５　ｋｇ
／ｃｎ＋２Ｇ程度の加圧下で粉末成形体を最高で６００
℃程度に加熱して、添加剤を気化、分解、燃焼などで飛
散・除去させることによって行われているが、脱脂工程
での添加剤の膨張力を低く抑える必要上、粉末成形体の
昇温速度は１〜３℃／ｈといった極めて遅い条件で行わ
れている。脱脂工程はこのように緩慢な昇温速度を採用
せざるを得ないため、通常５〜７日間もの長時間を要し
、著しく生産性が阻害されるといった問題があった。Therefore, traditionally this process was carried out at atmospheric pressure or at 5 kg
/cn+2G under pressure of up to 600
This is done by heating the powder to about ℃ and scattering and removing the additive through vaporization, decomposition, combustion, etc. However, as it is necessary to keep the expansion force of the additive low during the degreasing process, it is necessary to raise the temperature of the powder compact. The speed is extremely slow, such as 1 to 3°C/h. Since the degreasing process has no choice but to adopt such a slow temperature increase rate, it usually takes a long time of 5 to 7 days, which poses a problem in that productivity is significantly inhibited.

またこのように緩慢な昇温速度においても、鋳込成形法
では肉厚が３５ＩＩ１１以上、また射出成形法では肉厚
が２０ｍｍ以上の大きな粉末成形体になると、割れや亀
裂を発生させることなく脱脂することは従来不可能であ
った。In addition, even at such a slow temperature increase rate, large powder compacts with a wall thickness of 35II11 or more in the cast molding method, or 20 mm or more in the injection molding method can be degreased without cracking or cracking. It was previously impossible to do so.

〔発明の要旨〕[Summary of the invention]

本発明者らは、このような従来技術の欠点を解消するこ
とを目的とし、形状の大きな粉末成形体においても割れ
や亀裂などの欠陥を発生させることなく、短時間に脱脂
可能な方法を先に、特開昭６３−１４７８６９号、特開
昭６４−３０８０号において提案した。本発明は、これ
ら先に提案した方法の改良に関するものである。The present inventors aimed to eliminate such drawbacks of the conventional technology, and developed a method that allows degreasing in a short period of time without causing defects such as cracks or cracks even in large-sized powder compacts. This method was proposed in Japanese Patent Application Laid-open Nos. 147869/1986 and 3080/1984. The present invention relates to improvements to these previously proposed methods.

〔発明の開示〕[Disclosure of the invention]

上記目的は、焼結性粉末に添加剤を加えて成形した粉末
成形体を、該粉末成形体の表面の一部を露出面として残
すほかは、残余を気密性がある樹脂薄膜で被覆し、該被
覆した面を静水圧加圧した状態で該粉末成形体を加熱し
て、該添加剤を該露出面を通して飛散せしめることによ
って基本的に達成されるが、本発明者らはかかる方法を
基にして鋭意検討を行ない種々の条件を特定して工業的
有利な技術を確立したものである。The above purpose is to form a powder compact formed by adding additives to sinterable powder, leave a part of the surface of the powder compact as an exposed surface, and cover the rest with an airtight resin thin film. This is basically achieved by heating the powder compact while applying hydrostatic pressure to the coated surface to cause the additive to scatter through the exposed surface, but the present inventors have developed a method based on this method. After conducting intensive studies and specifying various conditions, an industrially advantageous technology was established.

本発明の目的は粉末成形体を、割れや亀裂などの欠陥を
発生させることなく、再現性よく脱脂することにあり、
更には安価にこれを行うことにある。The purpose of the present invention is to degrease a powder compact with good reproducibility without causing defects such as cracks or cracks.
Furthermore, it is possible to do this at low cost.

この本発明の目的は、焼結性粉末に添加剤を加えて成形
した粉末成形体より該添加剤を加熱・飛散させて除去す
る方法であって、予め該粉末成形体の一部を露出面とし
て残すほかは、残余を気密性があり、かつ弾性のある樹
脂薄膜で被覆し、該被覆した面で静水圧加圧した状態で
該粉末成形体を加熱し、該添加剤を露出面を通して飛散
せしめる方法において、添加剤の主成分に沸点１６０℃
以下の性質を有する化合物を用いて成形した粉末成形体
を、その成形時に存在する添加剤の少なくとも６０重景
気以上が粉末成形体に含まれる段階において、該被覆面
に３００Ｋｇ／ｃｍ’Ｇ以上の静水圧を付加し、以降は
５０Ｋｇ／ｃｍ２Ｇ以下、添加剤主成分の蒸気圧以上の
静水圧を付加して、添加剤主成分の沸点以上２３０℃以
下の温度に加熱することによって達成される。An object of the present invention is to provide a method for removing additives from a powder compact formed by adding additives to sinterable powder by heating and scattering the additives, in which a part of the powder compact is removed from the exposed surface in advance. In addition to leaving it as In this method, the main component of the additive has a boiling point of 160°C.
A powder molded body molded using a compound having the following properties is coated with a powder of 300 kg/cm'G or more at the stage where the powder molded body contains at least 60 layers of additives present at the time of molding. This is achieved by applying hydrostatic pressure, and then applying a hydrostatic pressure of 50 Kg/cm2G or less, which is higher than the vapor pressure of the main additive component, and heating to a temperature above the boiling point of the main additive component and below 230°C.

〔発明を実施するための具体的要件〕[Specific requirements for carrying out the invention]

以下、本発明の詳細な説明する。 The present invention will be explained in detail below.

本発明では、焼結体粉末に沸点１６０’Ｃ以下の性質を
有する化合物を主成分として加えて、射出成形法、Ｓｈ
込み成形法等によって成形した粉末成形体を用いる。In the present invention, a compound having a boiling point of 160'C or less is added to the sintered body powder as a main component, and injection molding method, Sh
A powder compact formed by a molding method or the like is used.

本発明における焼結体粉末とは、アル砧す、ジルコニア
、炭化ケイ素、などのセラくツク微粉末や、Ｆｅ、　Ｎ
ｉ、　Ｃｒなどの金属微粉末のよに、粉末を成形し、こ
れを例えば１０００〜２３００″Ｃに強熱すれば、その
融点以下の温度で結合し、緻密化する粉末をいう。In the present invention, the sintered body powder includes ceramic fine powder such as aluminum, zirconia, silicon carbide, Fe, N, etc.
i. Powder, such as fine metal powder such as Cr, which is formed and ignited to, for example, 1000 to 2300''C, is bonded and densified at a temperature below its melting point.

ここで添加剤の主成分が沸点１６０’Ｃ以下の化合物で
ある理由は、本発明で粉末成形体の表面に被覆する樹脂
膜は、粉末成形体を静水圧加圧する際に生しる寸法収縮
に追従する弾性と、加圧媒体を粉末成形体に浸透させな
い気密性を兼ね備えることが必要であるが、本発明者ら
は工業的に人手可能な種々の樹脂を、本発明に適用して
試験した結果、後述するような気密性と弾性を有する耐
熱温度の上限まで加熱温度を高めても、沸点が１６０’
Ｃ以上の化合物では本発明の脱脂時間が短いという特徴
が顕著ではなくなり、高温で長時間保持することが経済
性を損なうためである ここでいう主成分とは、９０重量％以上であることを意
味し、沸点は１気圧における値とする。The reason why the main component of the additive is a compound with a boiling point of 160'C or lower is that the resin film coated on the surface of the powder molded body in the present invention is produced by dimensional shrinkage that occurs when the powder molded body is subjected to isostatic pressure. Although it is necessary to have both elasticity that follows As a result, even if the heating temperature is increased to the upper limit of the heat-resistant temperature that has airtightness and elasticity as described below, the boiling point remains at 160'.
For compounds of C or higher, the short degreasing time characteristic of the present invention becomes less noticeable, and holding them at high temperatures for long periods of time impairs economic efficiency.The main component here means 90% by weight or more. The boiling point is the value at 1 atmosphere.

従って本発明では、従来用いられてきたポリスチレン、
ポリエチレン、ポリプロピレンなとの熱可塑性樹脂のよ
うに、沸点が不明確で加熱・飛散させるためには３００
℃以上の高温を必要とする添加剤を含んだ、射出成形法
によって得られた粉末成形体を対象とすることはできな
い。Therefore, in the present invention, the conventionally used polystyrene,
Thermoplastic resins such as polyethylene and polypropylene have unclear boiling points, and in order to be heated and dispersed, 300
Powder compacts obtained by injection molding that contain additives that require high temperatures of ℃ or higher cannot be targeted.

衆知のように、射出成形法によって粉末を成形するため
には、粉末と添加剤との混合物が金型に空隙なく圧入さ
れるための流動性が必要であり、更に、金型から粉末成
形体を変形させることなく取り出すための固形性が必要
である。従来の可塑性樹脂を添加剤として用いる方法に
おいては、樹脂の溶融温度まで加熱して流動性のある状
態で金型に圧入し、金型内で樹脂が固化するまで冷却し
たあと、取り出すことにより行われている。As is well known, in order to mold powder by injection molding, the mixture of powder and additives must have fluidity so that it can be press-fitted into a mold without any gaps, and in addition, it is necessary to have fluidity so that the mixture of powder and additives can be press-fitted into a mold without any gaps. It must have solidity so that it can be removed without deforming it. The conventional method of using plastic resin as an additive involves heating the resin to its melting temperature, press-fitting it into a mold in a fluid state, cooling it in the mold until it solidifies, and then taking it out. It is being said.

このように射出成形用の添加剤は、流動性のある状態か
ら固形性のある状態へ変化する性質が必要であるが、本
発明で特定する沸点が１６０℃以下の化合物を主成分と
する添加剤には、次のようなものがある。In this way, additives for injection molding must have the property of changing from a fluid state to a solid state. Agents include the following:

第１にチクソトロピー性、即ち、すり応力を加えた時に
は低粘度化して流動性の良い状態となり、静置状態にお
いては粘度の著しく高い性質を有する溶液である。これ
には例えばカルボキシメチルセルローズ、ポリビニルア
ルコール、カーボポールなどを０．５〜１０重量％溶解
させた水溶液などがあり、これら水溶液を添加剤として
用いて粉末と混合して射出成形すれば、金型に圧入する
ときはずり応力が働いて添加剤は流動状態になって、添
加剤と粉末の混合物は良好に金型内に流入し、粉末成形
体を金型より取り出すときには添加剤は高粘度の状態に
なるため粉末粒子間の結合は強くなり粉末成形体を変形
なく取り出すことができる。First, the solution has thixotropic properties, that is, it has a low viscosity and good fluidity when abrasion stress is applied, and has a significantly high viscosity when left standing. Examples of this include aqueous solutions in which carboxymethyl cellulose, polyvinyl alcohol, carbopol, etc. are dissolved in an amount of 0.5 to 10% by weight.If these aqueous solutions are used as additives and mixed with powder and injection molded, molding is possible. When press-fitting into the mold, shear stress acts and the additive becomes fluid, and the mixture of additive and powder flows smoothly into the mold, and when the powder compact is taken out of the mold, the additive becomes a highly viscous state. As a result, the bond between the powder particles becomes stronger and the powder compact can be taken out without deformation.

第２に溶液の粘度が温度に対して大きく変化する性質の
ものを用いることができる。これにはキサンタムガム、
ローカストビンガムなどの多糖類高分子やゼラチン、寒
天などを０．１〜５重量％溶解させた水溶液や、ポリビ
ニルアルコールの０．５〜５重量％の水ｔ８＃１．にレ
ゾルシン、カテコールと０．１〜０．５重量％溶解させ
た溶液や、更にメタノール、エタノール、アセトン、キ
シレン、トルエン、水などの溶媒にニトロセルローズ、
ポリエチレン、ポリエチレングリコール、ポリプロピレ
ングリコール、ポリ塩化ビニルなどを１−１０重量％溶
解させた水溶液があり、これら溶液を粉末と混合したも
のを５０〜９０℃に加熱しておけば流動性よく金型に流
入し、Ｏ〜２０’Ｃに冷却すれば溶液は高粘度の状態に
なって、金型より変形なく取り出すことができる。なお
、メチルセルローズ水溶液のように室温付近では低粘度
であって、５０〜７０″Ｃではゲル化し高粘度化する性
質のものは、金型の温度を５０〜７０℃に加熱しておき
室温で圧入すればよい。Secondly, it is possible to use a solution whose viscosity changes greatly with temperature. This includes xantham gum,
An aqueous solution containing 0.1 to 5% by weight of a polysaccharide polymer such as locust Bingham, gelatin, agar, etc., or an aqueous solution containing 0.5 to 5% by weight of polyvinyl alcohol T8#1. A solution containing 0.1 to 0.5% by weight of resorcinol or catechol, or nitrocellulose in a solvent such as methanol, ethanol, acetone, xylene, toluene, or water.
There are aqueous solutions containing 1-10% by weight of polyethylene, polyethylene glycol, polypropylene glycol, polyvinyl chloride, etc. If you mix these solutions with powder and heat them to 50-90°C, you can mold them with good fluidity. When the solution is cooled to 0 to 20'C, it becomes highly viscous and can be taken out from the mold without deformation. In addition, for products such as methylcellulose aqueous solution, which have a low viscosity near room temperature and have a property of gelling and becoming highly viscous at 50 to 70"C, heat the mold to 50 to 70"C and heat it at room temperature. Just press it in.

第３に沸点が１６０℃以下であって融点が比較的高い化
合物を用い融点以上、沸点以下の温度域で金型に圧入し
融点以下に冷却して添加剤を凝固させた後取り出すこと
によって行うこともできる。Thirdly, a compound with a boiling point of 160°C or less and a relatively high melting point is used, which is press-fitted into a mold at a temperature above the melting point and below the boiling point, cooled to below the melting point to solidify the additive, and then taken out. You can also do that.

この方法に適する化合物としては、ベンゼン（沸点８０
．１’Ｃ１融点５，５℃）、シクロヘキサン（７弗点８
０．７℃５融点６．５℃）、バラキシレン（沸点１３８
゜３℃２融点１３．３℃）、エチレンシアくン（沸点１
１７．３℃１融点１１．３℃）、トリオキサン（沸点１
１４゜５℃２融点６４．０℃）水などがある。Compounds suitable for this method include benzene (boiling point 80
．． 1'C1 melting point 5.5°C), cyclohexane (7 ml melting point 8
0.7℃5 melting point 6.5℃), baraxylene (boiling point 138
゜3℃2 melting point 13.3℃), ethylene cyanide (boiling point 1
17.3℃1 melting point 11.3℃), trioxane (boiling point 1
14°5°C2 melting point 64.0°C) water.

第４に水、トルエン、キシレン、酢酸エチル、メタノー
ルなどの溶媒に反応硬化型の樹脂を１〜１０！！ｉ量％
溶解させた溶液を用いることもでき、例えば水に尿素樹
脂、メラメン樹脂などを溶解させた１ｌｆｉＩや、トル
エン、キシレン、酢酸エチルなどの有機溶媒にエポキシ
樹脂、ウレタン樹脂、ポリエステル樹脂などを溶解させ
た樹脂を粉末と混合して、樹脂が未硬化の段階で金型に
圧入し、金型内で樹脂を硬化させた後に取り出すことに
よって行なうこともできる。Fourth, add a reaction-curing resin to a solvent such as water, toluene, xylene, ethyl acetate, or methanol. ! i amount%
Dissolved solutions can also be used, such as 1lfiI, which is a solution of urea resin, melamen resin, etc. in water, or epoxy resin, urethane resin, polyester resin, etc. dissolved in an organic solvent such as toluene, xylene, or ethyl acetate. It can also be carried out by mixing the resin with powder, press-fitting the resin into a mold while the resin is uncured, and taking it out after the resin has hardened within the mold.

このようにチクソトロピー性、粘度の温度依存性、溶解
凝固、反応硬化などの性質を利用して、添加剤を流動性
のある状態から固形性のある状態へ変化させ流動性があ
る状態で金型に圧入し、固形性のある状態に変化させた
後に取り出すことによって、本発明に適用可能な射出成
形法での粉末成形体を得ることができる。In this way, by utilizing properties such as thixotropy, temperature dependence of viscosity, melting and solidification, and reaction hardening, additives can be changed from a fluid state to a solid state and molded in a fluid state. By press-fitting the powder into a powder, changing it to a solid state, and then taking it out, it is possible to obtain a powder molded product by the injection molding method applicable to the present invention.

一方、鋳込み成形性では従来より水を９０重量％以上含
む添加剤が用いられており、従来の方法で得られた粉末
成形体で既に本発明に適用可能である。On the other hand, for casting moldability, additives containing 90% by weight or more of water have conventionally been used, and powder compacts obtained by conventional methods can already be applied to the present invention.

上述したような方法で得られた沸点が１６０℃以下の化
合物を主成分とする添加剤を用いて成形した粉末成形体
を、予め粉末成形体の表面を一部露出面として残す他は
、残余を気密性がある樹脂薄膜で被覆する。A powder compact molded using an additive mainly composed of a compound having a boiling point of 160° C. or lower obtained by the method described above is prepared in advance by leaving a part of the surface of the powder compact as an exposed surface. covered with an airtight resin film.

かかる樹脂薄膜による被覆は、例えば溶媒が揮発するこ
とや化学反応によって固化する液状の樹脂を成形体の表
面に直接塗布、吹き付け、もしくは浸漬−引き上げ等に
より薄く塗布し、必要により乾燥や加熱等の処理を加え
ることによって表面に樹脂膜を形成せしめることにより
実施することができる。この方法に使用可能な液状の樹
脂を列記すると例えば、ポリウレタン樹脂、シリコン樹
脂、エポキシ樹脂、アクリル樹脂、ポリエステル樹脂、
クロルプレン樹脂、フェノール樹脂等や酢酸ビニル系エ
マルジョン、スチレンブタジェン系ラテックス、アクリ
ル系エマルジョン、天然ゴムラテフクスなどの工業的に
製造されている樹脂を挙げることができる。For coating with such a resin thin film, for example, a liquid resin that solidifies due to solvent volatilization or chemical reaction is applied thinly to the surface of the molded object by direct coating, spraying, or dipping and pulling, followed by drying, heating, etc., if necessary. This can be carried out by applying a treatment to form a resin film on the surface. Liquid resins that can be used in this method include, for example, polyurethane resin, silicone resin, epoxy resin, acrylic resin, polyester resin,
Examples include industrially produced resins such as chlorprene resin, phenol resin, vinyl acetate emulsion, styrene butadiene latex, acrylic emulsion, and natural rubber latex.

さらにまた　アクリル樹脂、エポキシ樹脂、ポリエステ
ル樹脂などの中には、粉末の状態で塗布しこれを加熱す
れば該わ）末が融合し塗膜となるように加工された樹脂
があり、このような樹脂も使用可能である。Furthermore, among acrylic resins, epoxy resins, polyester resins, etc., there are resins that have been processed so that if they are applied in powder form and heated, the powders will fuse together to form a coating film. Resins can also be used.

これら工業的に人手可能な樹脂をわ）未成形体に被覆し
て加熱するにおいて、本発明の目的に必要な弾性、かつ
気密性を有する温度は本発明者らの実験的知見上、シリ
コン樹脂が最も高＜２３０℃、ウレタン樹脂２００℃１
アクリル樹脂１７０’Ｃなどが各種銘柄の中で現状の最
高温度である。According to the experimental findings of the present inventors, when coating an unmolded body with these industrially available resins and heating them, the temperature at which the silicone resin has the elasticity and airtightness necessary for the purpose of the present invention is determined. Highest <230℃, urethane resin 200℃1
Acrylic resin, such as 170'C, currently has the highest temperature among various brands.

被覆する薄膜の厚みは、粉末成形体の形状、粉末の粒径
、静水圧加圧の圧力、薄膜の種類などによって適宜選定
すればよく、気密性を保つに必要な最小限の厚み以上で
あればよい。The thickness of the thin film to be coated may be selected appropriately depending on the shape of the powder compact, the particle size of the powder, the pressure of hydrostatic pressing, the type of thin film, etc., and it may be at least the minimum thickness necessary to maintain airtightness. Bye.

本発明者らの実験的知見では、ｆｉ膜の厚みは通常１０
μｍ以上であることが望ましい、また、薄膜の厚みの上
限は特に規定されるものではないが、取扱の便宜上、５
１程度までが好ましい。According to the experimental findings of the present inventors, the thickness of the fi film is usually 10
The upper limit of the thickness of the thin film is not particularly specified, but for convenience of handling, it is desirable that the thickness is 5 μm or more.
It is preferably up to about 1.

このような樹脂薄膜で成形体表面を被覆し、後記するよ
うに該被覆薄膜を静水圧加圧した状態で加熱脱脂するこ
とにより、該樹脂薄膜は該静水圧で成形体表面に常に密
着し、また該静水圧は該薄膜を通して効果的に成形体に
伝えられ、添加剤が加熱されて生しる添加剤の蒸気圧以
上の圧力で成形体と等方向に加圧することによって、粉
末成形体を損傷させることなく脱脂することが出来るの
である。By coating the surface of the molded object with such a resin thin film and heating and degreasing the coating thin film under hydrostatic pressure as described later, the resin thin film always adheres to the surface of the molded object due to the hydrostatic pressure, In addition, the hydrostatic pressure is effectively transmitted to the compact through the thin film, and the powder compact is compressed in the same direction as the compact by applying pressure equal to or higher than the vapor pressure of the additive produced when the additive is heated. This allows for degreasing without causing damage.

本発明においては、粉末成形体の表面は少なくともその
一部を被覆せずにその部分を露出させておくことが必要
である。脱脂時には、該露出面より添加剤がＩＩ！散す
る。In the present invention, it is necessary that at least a part of the surface of the powder compact be left uncovered and exposed. During degreasing, the additive II! Scatter.

この一部を露出面として、粉末成形体を圧力容器に設置
する方法としては、例えば第１図に示したような方法が
ある。即ち、通気孔１を設けた圧力容２Ｓ２の内壁上に
、通気性のある多孔体３を置き、この多孔体３の上に粉
末成形体４を置いて、粉末成形体４と多孔体３の接触面
以外の粉末成形体４の表面、多孔体３の表面、多孔体３
の周囲の圧力容器２内壁面に樹脂を塗布する方法である
。As a method of installing the powder compact in a pressure vessel with this part exposed, there is a method as shown in FIG. 1, for example. That is, an air permeable porous body 3 is placed on the inner wall of the pressure volume 2S2 provided with the ventilation holes 1, a powder compact 4 is placed on this porous body 3, and the powder compact 4 and the porous body 3 are separated. The surface of the powder compact 4 other than the contact surface, the surface of the porous body 3, the porous body 3
In this method, resin is applied to the inner wall surface of the pressure vessel 2 around the .

このようにすれば多孔体３に接する粉末成形体４の表面
は薄膜で被覆していない露出面となり、この状態で被覆
面の周囲を加圧媒体で満たしこれを加圧すればよい、ま
たこの状態で静水圧加圧すれば、樹脂被覆面はその垂直
方向より均一な圧力を受は多孔体との接触面は同し圧力
によって多孔体３に押しつけられ粉末成形体４の表面は
全て均一な圧力を受けることになる。多孔体３には密度
を低く留めたセラ旦ンクス焼結体や焼結金属、あるいは
黒鉛などを用いることができる。In this way, the surface of the powder compact 4 in contact with the porous body 3 becomes an exposed surface that is not covered with a thin film, and in this state, the periphery of the coated surface can be filled with a pressurizing medium and pressurized. If hydrostatic pressure is applied in this state, the resin-coated surface will receive uniform pressure in the vertical direction, and the contact surface with the porous body will be pressed against the porous body 3 by the same pressure, and the entire surface of the powder compact 4 will be uniform. You will be under pressure. For the porous body 3, a ceramic sintered body, sintered metal, graphite, or the like, which has a low density, can be used.

露出面の位置は、？５）末成形体４の形状に応して選定
すればよいが、射出成形法においては金型キャビティの
ゲート部即ち金型への人口部に位置する部分を露出面と
しておけば概ね問題はない。What is the position of the exposed surface? 5) It may be selected depending on the shape of the final molded product 4, but in the injection molding method, there is generally no problem if the gate part of the mold cavity, that is, the part located at the artificial part to the mold, is made the exposed surface. .

露出面の面積は、この面より添加剤が飛散すると云う要
請があるため、その面積が小さすぎると脱脂に要する時
間が長くなるが、本発明者らの実験的知見によると、露
出面積は目安として全表面積の０．５〜２０％、好まし
くは１〜１０％程度の範囲で実施され、１％の露出面積
であっても、従来の方法よりもはるかに短時間に脱脂を
行なうことができる。The area of the exposed surface is required to prevent additives from scattering from this surface, so if the area is too small, the time required for degreasing will be longer; however, according to the inventors' experimental findings, the exposed area is a guideline. Degreasing is carried out in a range of 0.5 to 20% of the total surface area, preferably 1 to 10% of the total surface area, and even 1% of the exposed area can be degreased in a much shorter time than conventional methods. .

このようにして少なくとも一部を残し残部を樹脂薄膜で
被覆し、圧力容器に設置された粉末成形体は、次に該被
覆面を静水圧加圧した状態で加熱され、添加剤は飛散・
除去されるが、本発明においζは圧力の付加様式を次の
ように特定する５即ち、粉末成形体の成形特に存在する
添加剤の量の少なくとも６０重量％が粉末成形体に存在
する段階において、該被覆面に３００Ｋｇ／ｃｍ２Ｇ以
上の静水圧を付加し、以降は５０にｇ／ｃｍ２Ｇ以下、
添加剤主成分の芸気圧以上の静水圧を付加する加圧様式
である。In this way, the powder molded body is coated with at least a part of the resin thin film and the remaining part is covered with a resin thin film, and the powder molded body is placed in a pressure vessel. Next, the coated surface is heated with hydrostatic pressure applied, and the additives are dispersed and
However, in the present invention, ζ specifies the mode of application of pressure as follows. 5 That is, in the molding of a powder compact, particularly at the stage where at least 60% by weight of the amount of additive present is present in the powder compact. , a hydrostatic pressure of 300 kg/cm2G or more is applied to the coated surface, and thereafter a hydrostatic pressure of 50 g/cm2G or less,
This is a pressurization method that applies hydrostatic pressure that is higher than the pressure of the main ingredient of the additive.

この理由は第１に脱脂時に粉末成形体を損傷させないた
めである。本発明者らが実験を重ねる中で、粉末成形体
の肉厚が例えば３０１以上と大きくなると、粉末成形体
の添加剤主成分の蒸気圧以上の圧力で静水圧加圧しても
、脱脂時に割れが生しることを経験したが、この理由は
つぎのように推定した。肉厚が大きくなってくると特に
鋳込み成形／去では中心付近の粉末充填密度が低くなっ
てくるが、添加剤が少ない状態で粉末成形体を加圧し、
密度を高める力を加えていると、粉末成形体が収縮する
時に潰れるようにして割れてしまうということであり、
また射出成形法においても元来間られる粉末成形体の粉
末充填密度は鋳込み成形法のそれよりも低く、加熱脱脂
される過程で添加剤は必ずしも各部分で平均して・減少
しないため、同様に潰れるようにして割れてしまうとい
うＨＩ定である。この脱脂時の割れは添加剤の６０重量
％が存在する段階において、被覆面に３００Ｋｇ／ｃｍ
２Ｇ以上の静水圧を付加することによって、解決可能で
あることを本発明者らは見い出した。The reason for this is, first, to prevent damage to the powder compact during degreasing. Through repeated experiments, the present inventors found that when the wall thickness of a powder compact becomes large, for example, 30 mm or more, it cracks during degreasing even when hydrostatically pressurized at a pressure higher than the vapor pressure of the main component of the additive in the powder compact. The reason for this is estimated as follows. As the wall thickness increases, the powder packing density near the center becomes lower, especially in cast molding/removal, but if the powder compact is pressurized with less additives,
If a force is applied to increase the density, the powder compact will collapse and crack when it contracts.
In addition, in the injection molding method, the powder packing density of the powder compact that is originally formed is lower than that in the casting molding method, and the additives do not necessarily decrease on average in each part during the heating and degreasing process. It is a HI rating that it will break as if it were crushed. This cracking during degreasing occurs when 60% by weight of the additive is present on the coated surface.
The present inventors have found that this problem can be solved by applying a hydrostatic pressure of 2G or more.

この理由は、３００Ｋｇ／ｃｍ２Ｇ以上の高い圧力を添
加剤が存在する段階で付加すると、もともと添加剤は可
塑性、結合性を粉末に付与する性質のものであるため、
粉末成形体は割れることなく密度は最密充填値の近くま
で向上し、以降の加熱・加圧過程において外力によって
粉末成形体が潰れるような＄５３末粒子が移動し得る空
隙がなくなるためと推定する。The reason for this is that if a high pressure of 300 kg/cm2G or more is applied in the presence of additives, the additives originally have the property of imparting plasticity and binding properties to the powder.
It is assumed that this is because the density of the powder compact increases to close to the closest packing value without cracking, and there are no voids in which the $53 powder particles can move, which would cause the powder compact to be crushed by external force during the subsequent heating and pressurization process. do.

ここで付加する圧力の上限は特に設定する必要はないが
、１０ｔ／ｃｍ”［；以上とすることは設備費が増加す
る割りには効果が顕著でなく、粉末充填密度を出来るだ
け高め、焼結体のＮ、波向強度を向上させようとする目
的においては少なくとも３００Ｋｇ／ｃｍ２Ｇ以上、好
ましくは、５００Ｋｇ／ｃｍ２Ｇ〜２　ｔ／ｃｍ２Ｇで
ある。この高圧を付加するに適切な時間は、粉末成形体
の大きさによっても異なるが本発明者らの実験的知見上
、２０ｃｃの大きさでは３０秒〜１分間、１００ｃｃの
大きさでは１〜２分間、１１の大きさでは２〜３分間で
ある。There is no need to set an upper limit for the pressure applied here, but setting it above 10 t/cm" does not have a significant effect considering the increase in equipment costs. For the purpose of improving the N of the compact and the wave direction strength, it is at least 300 Kg/cm2G or more, preferably 500 Kg/cm2G to 2 t/cm2G.The appropriate time for applying this high pressure is Although it varies depending on the size of the body, based on the experimental findings of the present inventors, it is 30 seconds to 1 minute for a size of 20cc, 1 to 2 minutes for a size of 100cc, and 2 to 3 minutes for a size of 11. .

３００Ｋｇ／ｃｍ２Ｇ以上の高圧力を付加した後は、静
水圧加圧を５０Ｋｇ／ｃｍ２Ｇ以下、添加剤主成分の渾
気圧以上と、初期よりも低圧力を付加した状態で粉末成
形体を加熱する。この初期よりも低い圧力を付加する理
由は本発明の粉末成形体を損傷させることなく脱脂する
という目的においては添加剤主成分の蒸気圧以上の圧力
を付加しておけば、内圧によって粉末成形体が割れるこ
とはないためであり、本発明においては従来よりも著し
く脱脂時間が短いといっても￥５）未成形体の大きさが
１００ｃｃになると１０時間近くの脱脂時間が必要なた
め粉末の充填密度を高めた後にも高圧力を付加し続ける
ことは経済的に無駄なためである。また低圧力にするこ
とによって外力による潰れによって生しる粉末成形体の
割れを一層薙実に解消するためである。After applying a high pressure of 300 Kg/cm2G or more, the powder compact is heated while applying a lower pressure than the initial pressure such as hydrostatic pressurization of 50 Kg/cm2G or less and a pressure higher than the pumping pressure of the main component of the additive. The reason why a pressure lower than the initial pressure is applied is that in order to degrease the powder compact of the present invention without damaging it, if a pressure higher than the vapor pressure of the main component of the additive is applied, the internal pressure will cause the powder compact to be degreased without damaging the powder compact. This is because the degreasing time of the present invention is significantly shorter than that of the conventional method, but if the size of the unformed object is 100 cc, nearly 10 hours of degreasing time is required. This is because it is economically wasteful to continue applying high pressure even after increasing the density. In addition, by lowering the pressure, it is possible to further eliminate cracks in the powder compact caused by crushing due to external force.

なお本発明に使用・可能な添加剤主成分の例として示し
た化合物は、本発明で特定する最高２３０℃の加熱温度
において、蒸気圧が５０Ｋｇ／ｃｍ２Ｇを越えるものは
無い。It should be noted that none of the compounds shown as examples of the main additive components that can be used in the present invention have a vapor pressure exceeding 50 Kg/cm2G at the maximum heating temperature of 230° C. specified in the present invention.

また３００Ｋｇ／ｃｍ２Ｇ以上の高圧力を付加する時期
としては、加熱脱脂過程で添加剤が未だ成形特に存在す
る量の６０重量％以上含まれる段階において行なえば本
発明の目的は達成されるが、１００重量％含まれる段階
、即ち、加熱を行う前に高圧力で付加してもよい。この
加熱前に高圧力を付加すれば高額な高圧力設備の有効利
用がなされることにもなる。即ち、高圧力の付加時間は
数分間でよく引き続く低圧力での加圧時間は数時間〜１
０数時間を必要とするため、高圧力を付加した粉末成形
体を低圧力設備に移動してまとめて加熱処理すれば高圧
力設備の稼働率が上がり経清性が増してくる。In addition, the purpose of the present invention can be achieved by applying a high pressure of 300 kg/cm2G or more at a stage when the additive is still present in the molding process, especially at least 60% by weight during the heat degreasing process. It may also be applied at high pressure prior to the weight percent step, i.e. heating. If high pressure is applied before this heating, expensive high pressure equipment can be used effectively. That is, the application time of high pressure is often several minutes, and the application time of low pressure is often several hours to 1 hour.
Since this process requires several hours, if the powder compacts to which high pressure has been applied are moved to a low pressure facility and heat-treated all at once, the operating rate of the high pressure facility will increase and the efficiency of cleaning will increase.

この加熱前に高圧力を付加すると、第１図に示した通気
孔１より添加剤が液滴となって落下する現象が見られ高
圧力によって粉末成形体が収縮し添加剤が搾り出される
ことが理解される。If high pressure is applied before this heating, a phenomenon is observed in which the additive falls in the form of droplets from the vent hole 1 shown in Figure 1, and the powder compact shrinks due to the high pressure and the additive is squeezed out. is understood.

静水圧加圧の方法は粉末成形体を圧力容器に設置し、樹
脂被覆面を液体に浸した状態で、液体をポンプなどで加
圧する方法でよく、加圧用液体としてはグリセリン、流
動パラフィン、シリコンオイル、ポリエチレングリコー
ル、ホウ酸水溶液などがある。また高圧の空気、窒素な
どの気体を圧力容器に導く方法であってもよい。Hydrostatic pressurization can be carried out by placing the powder compact in a pressure vessel, immersing the resin-coated surface in the liquid, and pressurizing the liquid with a pump, etc. The pressurizing liquid may be glycerin, liquid paraffin, silicone, etc. Oil, polyethylene glycol, boric acid aqueous solution, etc. Alternatively, a method may be used in which a gas such as high-pressure air or nitrogen is introduced into a pressure vessel.

加熱温度は添加剤の主成分である化合物の沸点以上にす
ることを特定するが、この理由は脱脂を速やかに行うた
めである。本発明者らの実験的知見上、粉末成形体が２
０ｃｃの大きさでは、形状によっても異なるが沸点より
３０℃高く加熱すれば約５時間で添加剤の９９％以上を
飛散させることができ、１００ｃｃの大きさでは同しく
１０時間で可能である。The heating temperature is specified to be higher than the boiling point of the compound that is the main component of the additive, and the reason for this is to quickly perform degreasing. Based on the experimental findings of the present inventors, the powder compact is 2
With a size of 0 cc, more than 99% of the additive can be dispersed in about 5 hours by heating 30° C. above the boiling point, although this varies depending on the shape, and with a size of 100 cc, this can be done in 10 hours.

また沸点より５０℃高く加熱すれば１００ｃｃの大きさ
で約５時間で添加剤の９９％以上を飛散させることがで
き、ＩＩ！の大きさのものであっても約１５時間で可能
であり、次の焼結工程を問題なく行うことができる。Also, if heated 50°C above the boiling point, more than 99% of the additive can be dispersed in about 5 hours with a 100cc size, II! Even if the size of the sintering process is approximately 15 hours, the next sintering process can be carried out without any problem.

なお、昇温温度は任意であり、２００″Ｃ／ｈとしても
何ら問題はない。Note that the heating temperature is arbitrary, and there is no problem even if the heating temperature is 200''C/h.

［発明の効果］ 本発明は焼結性粉末に添加剤を加えて成形した粉末成形
体を表面の一部を露出面として残すほかは、残余を気密
性がある樹脂薄膜で被覆し、該被覆した面を静水圧加圧
した状態で該粉末成形体を加熱して、該添加物剤を該露
出面を通して飛散せしめる粉末成形体の脱脂方法におい
て、粉末成形体を再現よく損傷させずに脱脂し、またこ
れを安価に行うことを可能としたものである。[Effects of the Invention] The present invention provides a powder compact formed by adding additives to sinterable powder, leaving a part of the surface as an exposed surface, and covering the rest with an airtight resin thin film. In a method for degreasing a powder compact, the powder compact is heated while the exposed surface is subjected to hydrostatic pressure, and the additive is dispersed through the exposed surface. , and also made it possible to do this at low cost.

即ち、添加剤の主成分の蒸気圧以上の静水圧を粉末成形
体の樹脂被覆面に付加していても、粉末成形体の肉厚が
大きくなると脱脂時に割れることがあった問題を、脱脂
工程の初期に３００ｋｇ／ｃＪＧ以上の高い圧力を付加
して粉末充填密度を高めることによって、解消すること
ができ、また以降は５０ｋｇ／ｃＪＧ以下の圧力とする
ことによって、加圧操作を経済的に行うことを可能とし
た。また本発明を適用すれば、従来割れや亀裂を発生さ
せることなく脱脂することが不可能であった粉末成形体
の形状の大きさに限界を無くすることが可能となり、肉
厚が１００ｍｍであっても何ら問題なく脱脂が可能であ
る。更にまた粉末充填密度の高い脱脂された粉末成形体
が得られるため、引き続いて得られる焼結体の密度及び
強度は従来方法で得られた焼結体よりも顕著に高くなる
。In other words, even if a hydrostatic pressure higher than the vapor pressure of the main component of the additive is applied to the resin-coated surface of the powder compact, the problem of cracking during degreasing when the wall thickness of the powder compact becomes large can be solved in the degreasing process. This can be solved by increasing the powder packing density by applying a high pressure of 300 kg/cJG or more at the beginning of the process, and by applying a pressure of 50 kg/cJG or less thereafter, the pressurization operation can be performed economically. made it possible. Furthermore, by applying the present invention, it becomes possible to eliminate the limit on the size of the shape of powder compacts, which was conventionally impossible to degrease without causing cracks or cracks. However, degreasing is possible without any problems. Furthermore, since a degreased powder compact with a high powder packing density is obtained, the density and strength of the subsequently obtained sintered body are significantly higher than those obtained by conventional methods.

以下実施例によって、本発明を具体的に説明する。尚、
％は特に言及しない限り重量％を表すものとする。The present invention will be specifically described below with reference to Examples. still,
% represents weight % unless otherwise specified.

実施例１ 焼結ＰＬ粉末として、平均粒子径が０．２３μの窒化ケ
イ素粉末９６％、平均粒子径が０．１８μのアルごす粉
末１％、平均粒子径が０．２８μのイア）リア粉末３％
の組成で混合された粉末を用い、添加剤としては、水９
７％、アクリル系オリゴマー２％、ジエチルアミン１％
よりなる溶液を用いて、鋳込み形成法によって得られた
粉末成形体は直径５０ｍｍ、高さ７５ｍｍの円柱状の形
状で、外観上欠陥は認められず、添加剤を１５．５％含
んでおり、粉末充填密度は５６％であった。Example 1 As sintered PL powder, 96% silicon nitride powder with an average particle diameter of 0.23μ, 1% Algosu powder with an average particle diameter of 0.18μ, and Ia) rear powder with an average particle diameter of 0.28μ 3%
Using powder mixed with the composition of
7%, acrylic oligomer 2%, diethylamine 1%
The powder molded body obtained by the casting method using a solution consisting of the following was a cylindrical shape with a diameter of 50 mm and a height of 75 mm, no defects were observed in appearance, and it contained 15.5% of additives. Powder packing density was 56%.

第１図に示したように、５１φの通気孔１を設けた圧力
容器２の内壁に黒鉛質多孔体３（直１子５ｍｍ、厚み５
１１１Ｉ１１、空隙率２５％）を置き、その上に上記粉
末成形体３を置いた状態で、湿式硬化型ウレタン樹脂を
粉末成形体４、多孔体３の表面及び多孔体３の周囲５ｍ
ｍの圧力容器２内壁面にハケ塗りによって塗布し、厚さ
２３０μの膜を被覆した。As shown in FIG. 1, a graphite porous body 3 (5 mm in diameter, 5 mm thick,
111I11, porosity 25%), and with the powder molded body 3 placed thereon, wet curing urethane resin was applied to the powder molded body 4, the surface of the porous body 3, and the circumference of the porous body 3 for 5 m.
It was applied by brushing onto the inner wall surface of the pressure vessel 2 having a diameter of 1.5 m to form a film with a thickness of 230 μm.

次に圧力容器２をグリセリンで満たし室温にてグリセリ
ンをポンプ圧縮によって５００ｋｇ／ｃｍ２Ｇに加圧し
２分間保圧した。この間添加剤が通気孔ｌより　３．５
ｇ滴下した。Next, the pressure vessel 2 was filled with glycerin, and at room temperature, the glycerin was pressurized to 500 kg/cm2G by pump compression, and the pressure was maintained for 2 minutes. During this time, the additive is released from the ventilation hole 1.3.5
g was added dropwise.

次にグリセリンを６　ｋｇ／ｃＩ＋＋２Ｇに加圧した状
態でヒーターで加熱することによって、粉末成形体４を
昇温し、添加剤を通気孔１より大気中に飛散させた。グ
リセリンの加熱様式は、室温より１５０℃まで２００℃
／ｈの速度で昇温し、１５０’ｃにて８時間保持し、以
降は自然放麿により室温まで冷却した。Next, glycerin was pressurized to 6 kg/cI++2G and heated with a heater to raise the temperature of the powder compact 4, and the additive was dispersed into the atmosphere through the vent hole 1. The heating method for glycerin is 200℃ from room temperature to 150℃.
The temperature was raised at a rate of /h, held at 150'C for 8 hours, and then cooled to room temperature by natural release.

昇温より室温に冷却するまでの通算時間は１２時間であ
った。The total time from temperature rise to cooling to room temperature was 12 hours.

圧力容器２より取り出した粉末成形体４には、亀裂の発
生や薄膜の破損といった外観上の変化は全く認められず
、水及びジエチルアミンは９９％以上が飛散していた。In the powder compact 4 taken out from the pressure vessel 2, no changes in appearance such as occurrence of cracks or damage to the thin film were observed, and more than 99% of water and diethylamine were scattered.

また粉末充填率は５９％と脱脂前よりも増加していた。In addition, the powder filling rate was 59%, which was higher than before degreasing.

次に、この粉末成形体４を９　ｋｇ７ｃｍ２Ｇの窒素ガ
ス雰囲気下で１９００’Ｃに２時間加熱して窒化ケイ素
質のセラ５　’７クス焼結体を得た。得られた焼結体に
は大田は認められず密度は３．１４ｇ／ｃｍ”であった
。Next, this powder compact 4 was heated at 1900'C for 2 hours in a nitrogen gas atmosphere of 9 kg7cm2G to obtain a silicon nitride Cera5'7x sintered body. No Ota was observed in the obtained sintered body, and the density was 3.14 g/cm''.

これは窒化ケイ素の理論密度の９８％に相当する。This corresponds to 98% of the theoretical density of silicon nitride.

この焼結体より２０片の試験片を切出し、ＪＩＳｊ＋−
１６０１の規定に準して曲げ強度を測定した結果、゛↑
ニ均強度は８７Ｋｇ／ｍｍ２で標準偏差は５．２にｇ／
ｍｍ２であった。Twenty test pieces were cut out from this sintered body, and JISj+-
As a result of measuring bending strength according to the regulations of 1601, ゛↑
The uniform strength is 87Kg/mm2 and the standard deviation is 5.2g/mm2.
It was mm2.

比較例１ 実施例１でｍいたと回し窒化ケイ素質の円柱状わ）上べ
形体を、実施例１と全く同様にして圧力容器に設置し、
ウレタン樹脂膜を被覆した後、グリセリンを２００ｋｇ
／ｃｗ２Ｇの一定圧力に加圧した状ｇで実施例１と全く
同様な加熱様式によって、１５０℃にて８時間加熱し添
加剤をＷ１敗させた。圧力容器より取り出した粉末成形
体は長さ方向に亀裂が走った状態でほぼ真二つに割れて
いた。Comparative Example 1 A cylindrical silicon nitride body prepared in Example 1 was placed in a pressure vessel in exactly the same manner as in Example 1,
After coating with urethane resin film, apply 200 kg of glycerin.
The additive was heated at 150° C. for 8 hours in the same heating manner as in Example 1 under a constant pressure of /cw2G to cause W1 loss. The powder compact taken out from the pressure vessel was split into two pieces with cracks running along its length.

比較例２ 実施例１で用いたと同じ窒化ケイ素質の円柱状わ）末成
形体を、ウレタン樹脂膜を被覆せずに、そのまま５　ｋ
ｇ／ｃｍｔＧの加圧空気中でｌ’ｃ／ｈの極めて遅い昇
温速度で室温より１５０’Ｃまで昇温し添加剤をｉ敗さ
せた。脱脂後の粉末成形体は４片に分割された状態で破
損していた。Comparative Example 2 The same cylindrical silicon nitride molded product used in Example 1 was heated for 5 k without being coated with a urethane resin film.
The additives were heated from room temperature to 150'C at an extremely slow temperature increase rate of l'c/h in pressurized air of g/cmtG to destroy the additives. The powder compact after degreasing was broken and divided into four pieces.

実施例１と比較例１との比較より、添加剤を含んだ段階
で一旦高圧力の静水圧を付加しておけば、脱脂工程にお
いて粉末成形体に１員傷が発生しないのに対して、一定
の静水圧を付加したままだと、静水圧の方が添加剤の華
気圧より高くても、損傷が発生し易いことが分かる。From a comparison between Example 1 and Comparative Example 1, it was found that if high hydrostatic pressure was applied at the stage containing additives, no single-member scratches would occur in the powder compact during the degreasing process. It can be seen that if a constant hydrostatic pressure is applied, damage is likely to occur even if the hydrostatic pressure is higher than the flower pressure of the additive.

また実施例１と比較例２より、従来の静水圧を付加せず
に加熱・脱脂する方法では著しく緩慢な昇温速度であっ
てもｔ負傷してしまうことがわかる。Further, from Example 1 and Comparative Example 2, it can be seen that the conventional method of heating and degreasing without applying hydrostatic pressure causes injury even if the temperature rise rate is extremely slow.

実施例２ 焼結性粉末として、平均粒子径が０．２６ｕのアルミナ
粉末９９．５％、平均粒子径が０．３３μのマグネシア
わ）未０．５％の組成で混合された粉末を用い、添加剤
は実施例１と全く同し溶液を用いて、鋳込み成形法によ
って得られた粉末成形体は、直径が６０ｍｍ、高さ８０
ｍｍの円柱状の形状で外観上欠陥は認められす、添加剤
を１４．７％含んでおり、粉末充填密度は５５％であっ
た。Example 2 As a sinterable powder, a powder mixed with 99.5% alumina powder with an average particle size of 0.26u and 0.5% of magnesia powder with an average particle size of 0.33μ was used, Using the same solution as in Example 1, the powder compact obtained by the casting method had a diameter of 60 mm and a height of 80 mm.
It had a cylindrical shape of 1.0 mm in diameter, had no visible defects, contained 14.7% of additives, and had a powder packing density of 55%.

実施例１と同様にして５問φの通気孔を設けた圧力容器
の内壁にアルミナ質多孔体（直径６０ｍｍ、厚み１０ｍ
ｍ、空隙率３０％）を置き、その上に粉末成形体を置い
た状態で溶媒型アクリル樹脂を実施例１と同様にして塗
布し、厚さ１９０μの膜を被覆した。A porous alumina material (diameter 60 mm, thickness 10 m
m, porosity 30%), and with the powder molded body placed thereon, a solvent-based acrylic resin was applied in the same manner as in Example 1 to coat a film with a thickness of 190 μm.

次に圧力容器を３０％ホウ酸水で満たし、室温にてホウ
酸水をポンプ圧縮によってｌ　ｔ／ｃｍ２Ｇに加圧し２
分間保圧した。この間添加剤が通気孔より５．７ｇ滴下
した。Next, the pressure vessel was filled with 30% boric acid water, and the boric acid water was pressurized to 1 t/cm2G by pump compression at room temperature.
The pressure was held for a minute. During this time, 5.7 g of additive was dropped from the vent hole.

次に、圧力容器のホウ酸水を５　ｋｇ／ｃｍ２Ｇの加圧
空気に置き換えて、ヒーターで加熱することによって、
粉末成形体を界温し、添加剤を通気孔より大気に飛散さ
せた。加圧空気の加熱様式は室温より　１４０’Ｃまで
３００’Ｃ／ｈの速度で昇温し、１４０℃にて１２時間
保持し以降は自然放冷によって室温まで冷却した。昇温
より室温にて冷却するまでの通算時間は１５時間であっ
た。Next, by replacing the boric acid water in the pressure vessel with pressurized air at 5 kg/cm2G and heating it with a heater,
The powder compact was brought to ambient temperature, and the additive was dispersed into the atmosphere through the vent hole. The heating method of the pressurized air was to raise the temperature from room temperature to 140'C at a rate of 300'C/h, hold it at 140°C for 12 hours, and then cool it down to room temperature by natural cooling. The total time from temperature rise to cooling at room temperature was 15 hours.

耐熱容器より取り出した粉末成形体には、亀裂の発生や
薄膜の破損といった外観上の変化は全く認められず、水
及びジエチルアミンは９９％以上が飛散していた。また
粉末充填率は６２％と脱脂前よりも増加していた。In the powder compact taken out from the heat-resistant container, no changes in appearance such as generation of cracks or damage to the thin film were observed, and more than 99% of water and diethylamine were scattered. In addition, the powder filling rate was 62%, which was higher than before degreasing.

次に、この粉末成形体を１気圧の水素ガス雰囲気下で１
８００’Ｃに２時間加熱してセラミックス焼結体を得た
。得られた焼結体の密度は３．９５ｇ／ｃｍ３であった
が、これはアルミナの理論密度の９８％に相当する。Next, this powder compact was heated for 1 hour in a hydrogen gas atmosphere of 1 atm.
A ceramic sintered body was obtained by heating at 800'C for 2 hours. The density of the obtained sintered body was 3.95 g/cm3, which corresponds to 98% of the theoretical density of alumina.

この焼結体より２０片の試験片を切出し、ＪＩＳＲ−１
６０１の規定に準して曲げ強度を測定した結果、平均強
度は６２ｋｇ／ｍｍ”で標準偏差は３．７ｋｇ／ｍ−で
あった。Twenty test pieces were cut out from this sintered body, and JISR-1
As a result of measuring the bending strength according to the regulations of 601, the average strength was 62 kg/mm'' and the standard deviation was 3.7 kg/m.

実施例３ 焼結性粉末として、平均粒子径が０．２３μの炭化ケイ
素粉末９７．５％、平均粒子径が０．０７μの炭素粉末
、２％平均粒子径が０．５６μのホウ素粉末０．５％の
組成で混合された粉末を用い、この粉末１００重量部に
添加剤としてキサンタンガムの１％水溶液を２０重量部
を加えて射出成形法によって成形した粉末成形体は、直
径５０ｍｍ、高さ１００ｍｍの円柱状の形状で粉末充填
密度は５１％であった。射出成形条件として、粉末と添
加剤の混合物は６０℃に加熱された流動性の良い状態で
金型に圧入され、金型にて１０℃まで冷却されて保形性
のある状態で欠損を生しることなく金型より取り出され
た。Example 3 As sinterable powders, 97.5% silicon carbide powder with an average particle diameter of 0.23μ, carbon powder with an average particle diameter of 0.07μ, and 2% boron powder with an average particle diameter of 0.56μ are used. Using a powder mixed with a composition of 5%, 20 parts by weight of a 1% aqueous solution of xanthan gum was added as an additive to 100 parts by weight of this powder, and the molded powder was molded by injection molding, with a diameter of 50 mm and a height of 100 mm. It had a cylindrical shape and the powder packing density was 51%. As for the injection molding conditions, the mixture of powder and additives is heated to 60°C and is press-fitted into a mold with good fluidity, and then cooled in the mold to 10°C to form defects while retaining its shape. It was removed from the mold without any damage.

実施例１と同様にして、圧力容器の内壁に黒鉛質多孔体
を置き、その上に上記粉末成形体を置いた状態で、シリ
コン樹脂をスプレーによって、実施例１と同様に塗布し
、厚さ１６０μの膜を被覆した。In the same manner as in Example 1, a graphite porous body was placed on the inner wall of a pressure vessel, and with the powder molded body placed on top of it, silicone resin was applied by spraying in the same manner as in Example 1, and the thickness was A 160μ membrane was coated.

次に圧力容器をグリセリンで満たし、グリセリンを加圧
した状態で室温より１７０’Ｃまでは３００℃／ｈの速
度で昇温し、１７０℃で７時間保持した後冷却した。加
圧様式としては、１７０’Ｃに到達より３０分間後に７
００ｋｇ／ｃｍ２Ｇの圧力を２分間付加し、それ以外は
ｌｏｋｇ／ｃｏ２Ｇとした。高圧力を付加した段階での
添加剤含有量は射出成形時に存在した量の８２％と推定
された。昇温まり室温に冷却するまでの通算時間は１１
時間であった。Next, the pressure vessel was filled with glycerin, and while the glycerin was pressurized, the temperature was raised from room temperature to 170'C at a rate of 300°C/h, maintained at 170°C for 7 hours, and then cooled. The pressurization method is 70 minutes after reaching 170'C.
A pressure of 00 kg/cm2G was applied for 2 minutes, and the pressure was 100 kg/co2G for the rest of the time. The additive content at the high pressure stage was estimated to be 82% of the amount present during injection molding. The total time from heating up to cooling down to room temperature is 11
It was time.

耐熱容器より取り出した粉末成形体には、亀裂の発生や
薄膜の破損といった外観上の変化は全く認められず、水
は９９％以上が飛散していた。また粉末充填率は６０％
と脱脂前よりも増加していた。In the powder compact taken out from the heat-resistant container, no changes in appearance such as cracking or damage to the thin film were observed, and more than 99% of the water had been scattered. Also, the powder filling rate is 60%
and increased compared to before degreasing.

次に、この粉末成形体を１０−３〜１０−’ｓｍｏｇの
真空雰囲気下で２０５０℃に２時間加熱してセラミック
ス焼結体を得た。得られた焼結体の密度は３．１４ｇ／
ｃ１であったが、これは炭化ケイ素の理論密度の９８％
に相当する。Next, this powder compact was heated at 2050° C. for 2 hours in a vacuum atmosphere of 10 −3 to 10 −′ smog to obtain a ceramic sintered body. The density of the obtained sintered body was 3.14 g/
c1, which is 98% of the theoretical density of silicon carbide.
corresponds to

この焼結体より２０片の試験片を切出し、ＪＩＳＲ−１
６０１の規定に準して曲げ強度を測定した結果、平均強
度は７８ｋｇ／ｎｍ”で標準偏差は４．１ｋｇ／ｍｍ２
であった。Twenty test pieces were cut out from this sintered body, and JISR-1
As a result of measuring the bending strength according to the regulations of 601, the average strength was 78 kg/nm'' and the standard deviation was 4.1 kg/mm2.
Met.

実施例４ 焼結体粉末として、平均粒子径が１０μのＴｉ粉末９０
％、平均粒子径が１．５μのＣｏ粉末１０％の組成で混
合された粉末を用い、この混合粉末１００重量部に添加
剤としてベンゼンを１９重量部加えて射出成形法によっ
て成形した粉末成形体は、直径５０ｍｍ、高さ１００Ｉ
ＩＩ１１の円柱状の形状で、粉末充填密度は５２％であ
った。Example 4 Ti powder 90 with an average particle size of 10μ was used as the sintered body powder.
%, an average particle diameter of 1.5μ, a powder mixture of 10% Co powder, 19 parts by weight of benzene as an additive was added to 100 parts by weight of this mixed powder, and the powder compact was molded by injection molding. has a diameter of 50mm and a height of 100I.
II11 had a cylindrical shape and a powder packing density of 52%.

射出成形条件として、粉末と添加剤との混合物は２０℃
の流動性の良い状態で金型に圧入され、金型にて一５℃
まで冷却されてベンゼンが凍結し、保形性のある状態で
欠陥を生じることなく、金型より取り出された。As injection molding conditions, the mixture of powder and additives was heated to 20°C.
It is press-fitted into a mold with good fluidity, and the temperature is -5℃ in the mold.
The benzene was cooled to a certain temperature and the benzene was frozen, and it was removed from the mold in a shape-retaining state without any defects.

実施例１と同様にして、圧力容器に上記粉末成形体を設
置し、ウレタン樹脂膜を被覆して、５００ｋｇ／ｃｖａ
２Ｇの静水圧を室温にて付加した後、１０ｋｇ／Ｃｌ１
１２Ｇの静水圧を付加した状態で１５０℃で８特開加熱
し、添加剤を通気孔より飛散させた。In the same manner as in Example 1, the powder compact was placed in a pressure vessel, covered with a urethane resin film, and
After applying 2G hydrostatic pressure at room temperature, 10kg/Cl1
The mixture was heated at 150° C. under 8 JP-A-8-2012 with a hydrostatic pressure of 12 G applied, and the additive was dispersed through the ventilation holes.

耐熱容器より取り出した粉末成形体には、亀裂の発生や
薄膜の破損といった外観上の変化は全く認められず、ベ
ンゼンは９９％以上が飛散していた。In the powder compact taken out from the heat-resistant container, no changes in appearance such as cracking or damage to the thin film were observed, and more than 99% of the benzene was scattered.

また粉末充填率は６２％と脱脂前よりも増加していた。In addition, the powder filling rate was 62%, which was higher than before degreasing.

次に、この粉末成形体を１Ｏ−４〜１０−　’ｍｍＨｇ
の真空雰囲気下で１２００℃に２時間加熱して焼結合金
を得た。得られた焼結合金の密度は４．８９ｇ／ｃｍ３
であったが、これは理論密度の９９％に相当する。Next, this powder compact was heated to 1O-4 to 10-'mmHg.
A sintered alloy was obtained by heating at 1200° C. for 2 hours in a vacuum atmosphere. The density of the obtained sintered alloy is 4.89 g/cm3
However, this corresponds to 99% of the theoretical density.

この焼結合金より２０片の試験片を切出し、ＪＩＳＺ−
２２０１の規定に準して引張り強度を測定した結果、平
均強度は６３Ｋｇ／ｍ−で標準偏差は２．１Ｋｇ／ｍｍ
”であった。Twenty test pieces were cut from this sintered alloy, and JISZ-
As a result of measuring the tensile strength according to the regulations of 2201, the average strength was 63Kg/m- and the standard deviation was 2.1Kg/mm.
"Met.

比較例３ 実施例４で用いたと同し円柱状の金属粉木酸形体を実施
例４と全く同＋ににして圧力容器に設置し、ウレタン樹
脂膜を被覆した後、グリセリンを１５０ｋｇ／ｃｍ２Ｇ
の一定圧力に加圧した状態で実施例４と全く同様な加熱
様式によって添加剤を飛散させた。圧力容器より取り出
した粉末成形体は、長さ方向に亀裂が走った状態でほぼ
真二つに割れていた。Comparative Example 3 The same cylindrical metal powder wood acid form used in Example 4 was placed in a pressure vessel in exactly the same manner as in Example 4, and after being covered with a urethane resin film, glycerin was applied at 150 kg/cm2G.
The additives were dispersed using the same heating method as in Example 4 under a constant pressure of . The powder compact taken out from the pressure vessel was broken almost in two with cracks running in the length direction.

実施例５ 焼結性粉末として、平均粒子径が５μのｒｅ粉末９５％
、平均粒子径が２μのＣｕ粉末５％の組成で混合された
粉末を用い添加剤としてアセトンにポリプロピレン５％
を溶解させた溶液を１７重量部加えて射出成形法によっ
て成形した粉末成形体は、直径５０ｍｍ、高さ９０ｍｍ
の円柱状の形状で、粉末充填密度は５１％であった。Example 5 As sinterable powder, 95% re powder with an average particle size of 5μ
, using a powder mixed with a composition of 5% Cu powder with an average particle size of 2μ, and 5% polypropylene in acetone as an additive.
The powder molded body was molded by injection molding with 17 parts by weight of a solution dissolved in the powder having a diameter of 50 mm and a height of 90 mm.
It had a cylindrical shape, and the powder packing density was 51%.

射出成形条件として、粉末と添加剤との混合物は３０℃
の流動性の良い状態で金型に圧入され、金型にて０℃ま
で冷却されて保形性のある状態で欠損を生しることなく
、金型より取り出された。As injection molding conditions, the mixture of powder and additives was heated to 30°C.
It was press-fitted into a mold with good fluidity, cooled to 0° C. in the mold, and taken out from the mold in a shape-retaining state without any defects.

実施例１と同様にして、圧力容器の内壁に黒鉛質多孔体
を置き、その上に上記粉末成形体を置いた状態でウレタ
ン変性エポキン樹脂を実施例１と同様にして塗布し、厚
さ２１０μの膜を被覆した。In the same manner as in Example 1, a graphite porous body was placed on the inner wall of a pressure vessel, and with the powder molded body placed thereon, urethane-modified Epoquine resin was applied in the same manner as in Example 1 to a thickness of 210 μm. coated with a film of

次に、圧力容器を流動パラフィンで満たし、原動パラフ
ィンを加圧した状態で室温より１４０’Ｃまでは２００
℃／ｈの速度で昇温し、１４０℃で７時間保持した後冷
却した。加圧様式としては、１４０℃に到徨より１時間
後に５００ｋｇ／ｃｍ２Ｇの圧力を２分間付加し、それ
以外は９ｋｇ／ｃｍｚＧとした。高圧を付加した段階で
の添加剤含有量は射出成形時に存在した星の７５％と推
察された。Next, the pressure vessel was filled with liquid paraffin, and the liquid paraffin was heated at 200°C from room temperature to 140'C.
The temperature was raised at a rate of 140° C./h, maintained at 140° C. for 7 hours, and then cooled. As for the pressurization mode, a pressure of 500 kg/cm2G was applied for 2 minutes one hour after reaching 140°C, and the pressure was 9kg/cm2G for the rest of the time. The additive content at the stage when high pressure was applied was estimated to be 75% of that present during injection molding.

耐熱容器より取り出した粉末成形体には、亀裂の発生や
薄膜の破ｍといった外観上の変化は全くＬ８められず、
アセトンは９９％以上が飛散していた。The powder compact taken out from the heat-resistant container showed no external changes such as cracks or thin film breakage.
More than 99% of the acetone was scattered.

また！５）未充填率は５９％と脱脂前よりも増加してい
た。Also! 5) The unfilled rate was 59%, which was higher than before degreasing.

次に、この粉末成形体を１０−４〜１０−’ｍｍｔ１ｇ
の真空雰囲気下で１１５０’Ｃに２時間加熱して焼結合
金を得た。得られた焼結合金の密度は７．８５ｇ／ｃ−
であったが、理論密度の９９％に相当する。Next, this powder compact is 10-4 to 10-'mmt1g.
A sintered alloy was obtained by heating at 1150'C for 2 hours in a vacuum atmosphere. The density of the obtained sintered alloy was 7.85 g/c-
However, this corresponds to 99% of the theoretical density.

この焼結合金より２０片の試験片を切出し、ＪＩ５７、
−２２０１の規定に準して引張り強度をθり定した結果
、平均強度は５１ｋｇ／ｍｍ２で標準偏差は２．９ｋｇ
／ｍ−であった。Twenty test pieces were cut from this sintered alloy, JI57,
-2201, the average strength was 51 kg/mm2 and the standard deviation was 2.9 kg.
/m-.

【図面の簡単な説明】[Brief explanation of drawings]

第１図は本発明にて得た粉末成形体が、加圧容器に設置
された状態を示す断面図である。 第１図において、 ｌ　　−通気孔、　　４−粉末成形体、２　　圧力容器
、　５−　樹脂膜、 ３−　多孔体、　　６−　加圧媒体装入ノズルを示す。FIG. 1 is a sectional view showing a state in which a powder compact obtained according to the present invention is placed in a pressurized container. In FIG. 1, 1-vent hole, 4-powder compact, 2-pressure vessel, 5-resin membrane, 3-porous body, 6-pressurized medium charging nozzle are shown.

Claims (1)

【特許請求の範囲】 １）焼結性粉末に添加剤を加えて成形した粉末成形体よ
り該添加剤を加熱・飛散させて除去する方法であって、
予め該粉末成形体の表面の少なくとも一部を露出面とし
て残すほかは、残余を気密性が有り、かつ弾性のある樹
脂薄膜で被覆し、該被覆した面を静水圧加圧した状態で
該粉末成形体を加熱し、該添加剤を該露出面を通して飛
散せしめる方法において、添加剤の主成分に沸点１６０
℃以下の性質を有する化合物を用いて成形した粉末成形
体を、その成形時に存在する添加剤の量の少なくとも６
０重量％以上が粉末成形体に含まれる段階において、該
被覆面に３００ｋｇ／ｃｍ＾２Ｇ以上の静水圧を付加し
、以降は５０ｋｇ／ｃｍ＾２Ｇ以下、添加剤主成分の蒸
気圧以上の静水圧を付加して、添加剤主成分の沸点以上
、２３０℃以下の温度に加熱することを特徴とする粉末
成形体中の添加剤の除去方法。 ２）粉末成形体が射出成形法により成形されたものであ
る特許請求の範囲第１項記載の方法。 ３）粉末成形体が泥漿鋳込み成形法により成形されたも
のである特許請求の範囲第１項記載の方法。 ４）添加剤が除去された粉末成形体を引続き強熱して焼
結体とする特許請求の範囲第１項〜第３項のいずれかに
記載の方法。[Claims] 1) A method for removing additives from a powder compact formed by adding additives to sinterable powder by heating and scattering the additives, comprising:
Except for leaving at least a part of the surface of the powder compact as an exposed surface, the remaining part is covered with an airtight and elastic resin thin film, and the powder is heated with hydrostatic pressure applied to the coated surface. In a method in which the molded body is heated to cause the additive to scatter through the exposed surface, the main component of the additive has a boiling point of 160
A powder molded body molded using a compound having properties below
At the stage where 0% by weight or more is contained in the powder compact, a hydrostatic pressure of 300 kg/cm^2G or more is applied to the coated surface, and thereafter a hydrostatic pressure of 50kg/cm^2G or less, which is higher than the vapor pressure of the main component of the additive, is applied to the coated surface. A method for removing additives from a powder compact, which comprises applying water pressure to a temperature above the boiling point of the main component of the additive and below 230°C. 2) The method according to claim 1, wherein the powder compact is molded by an injection molding method. 3) The method according to claim 1, wherein the powder compact is formed by a slurry casting method. 4) The method according to any one of claims 1 to 3, wherein the powder compact from which the additive has been removed is subsequently ignited to form a sintered body.