JPH06212204A - Production of molded articles - Google Patents
Production of molded articlesInfo
- Publication number
- JPH06212204A JPH06212204A JP50A JP407593A JPH06212204A JP H06212204 A JPH06212204 A JP H06212204A JP 50 A JP50 A JP 50A JP 407593 A JP407593 A JP 407593A JP H06212204 A JPH06212204 A JP H06212204A
- Authority
- JP
- Japan
- Prior art keywords
- powder
- weight
- parts
- temporary binder
- added
- 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.)
- Granted
Links
Landscapes
- Compositions Of Oxide Ceramics (AREA)
- Producing Shaped Articles From Materials (AREA)
- Press-Shaping Or Shaping Using Conveyers (AREA)
- Powder Metallurgy (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、複数の粉粒体からなる
原材料および短繊維を含有する粉粒体原料に液状添加剤
を加え、一軸加圧成形法または射出成形法により予備成
形体を得た後、焼成して成形体を得る成形体の製造方法
に関する。FIELD OF THE INVENTION The present invention is to add a liquid additive to a raw material consisting of a plurality of powders and a powdery raw material containing short fibers, and to prepare a preform by a uniaxial pressure molding method or an injection molding method. The present invention relates to a method for producing a molded product by firing to obtain a molded product.
【０００２】[0002]
【従来の技術】従来より、粉粒体状の原材料を用いて成
形体を得るために、予め所定の形状を有する予備成形体
を仮成形した後焼成することが行われている。この予備
成形体を成形する方法としては、一軸加圧成形法、静水
圧加圧成形法（ＣＩＰ）または一軸加圧成形法を用いて
静水圧加圧状態を経る方法等が知られている。2. Description of the Related Art Conventionally, in order to obtain a compact using a raw material in the form of powder or granules, a preliminary compact having a predetermined shape is preliminarily molded and then fired. As a method of molding this preformed body, a method such as a uniaxial pressure molding method, a hydrostatic pressure molding method (CIP), or a method of passing a hydrostatic pressure state using a uniaxial pressure molding method is known.
【０００３】この種の方法の中、例えば本出願人は、予
め粉粒体状の原材料に液状添加剤を加えて混合した混合
物を、一軸加圧成形法により静水圧加圧状態を経つつ余
分な液状添加剤を排出して予備成形体を得る方法を提案
している（特開平４−２１１９０４号公報参照）。これ
により、従来、液体を加圧媒体としてゴム型を使用する
ことでしかなし得なかった静水圧加圧成形法を、金型に
よる一軸加圧成形法により実現することができる等、種
々の利点が得られている。Among the methods of this kind, for example, the applicant of the present invention has a method in which a mixture obtained by previously adding a liquid additive to a raw material in the form of powder and granules and mixing the mixture is subjected to a hydrostatic pressure state by a uniaxial pressure molding method. A method has been proposed in which various liquid additives are discharged to obtain a preform (see Japanese Patent Application Laid-Open No. 4-212904). As a result, various advantages such as the hydrostatic pressure molding method, which has hitherto been possible only by using a rubber mold as a pressure medium, can be realized by a uniaxial pressure molding method using a mold. Has been obtained.
【０００４】[0004]
【発明が解決しようとする課題】ところで、近年、原材
料の微粒子化、すなわち、その粒径がμｍからサブミク
ロンあるいはそれ以下のものが使用されるようになり、
この種の原材料を用いて予備成形体を得ることが望まれ
ている。ところが、原材料が微粒子化されると、予備成
形体を得るための金型クリアランスを、従来の７０μｍ
乃至１００μｍから１０μｍ乃至３０μｍにまで狭める
必要があり、特に形状の複雑な金型では、その製造費が
膨大なものとなってしまう。さらに、原材料と液体添加
剤とのレオロジー特性がチクソトロピー的である場合、
金型クリアランスからの漏洩が著しいものとなるおそれ
がある。By the way, in recent years, raw materials have been made finer, that is, those having a particle size of from μm to submicron or less have been used,
It is desired to obtain a preform by using this kind of raw material. However, when the raw material is made into fine particles, the mold clearance for obtaining the preform is 70 μm, which is smaller than the conventional mold clearance.
It is necessary to narrow the thickness to 100 μm to 10 μm to 30 μm, and the manufacturing cost of a die having a complicated shape becomes enormous. Furthermore, if the rheological properties of the raw materials and liquid additives are thixotropic,
Leakage from the mold clearance may be significant.
【０００５】本発明は、この種の問題を解決するもので
あり、特に、微粒子化された原材料を予備成形する際
に、この原材料の漏洩を阻止することができるととも
に、強度並びに品質に優れた成形体を得ることが可能な
成形体の製造方法を提供することを目的とする。The present invention solves this kind of problem, and in particular, at the time of preforming a finely divided raw material, it is possible to prevent the raw material from leaking and it is excellent in strength and quality. It is an object of the present invention to provide a method for producing a molded product, which is capable of obtaining a molded product.
【０００６】[0006]
【課題を解決するための手段】前記課題を解決するため
に、本発明は、複数の粉粒体からなる原材料に、液状添
加剤および前記液状添加剤と反応結合して該原材料の各
粉粒体を囲繞する仮結合剤を加えて混合する第１工程
と、前記第１工程で得られた混合物を一軸加圧成形法ま
たは射出成形法により余分の液状添加剤を除去して予備
成形体を得る第２工程と、前記第２工程で得られた予備
成形体を焼成して成形体を得る第３工程と、を備えるこ
とを特徴とする。In order to solve the above-mentioned problems, the present invention relates to a raw material composed of a plurality of powder particles, and a liquid additive and each powder particle of the raw material by reacting with the liquid additive. The first step of adding a temporary binder to surround the body and mixing, and removing the excess liquid additive from the mixture obtained in the first step by a uniaxial pressure molding method or an injection molding method to form a preform. It is characterized by comprising a second step of obtaining and a third step of firing the preformed article obtained in the second step to obtain a formed article.
【０００７】また、前記仮結合剤が、ステアリン酸系誘
導体であることが好ましく、さらに前記ステアリン酸系
誘導体が、ステアリン酸、ステアリン酸アミド、ステア
リン酸アルミニウム、ステアリン酸マグネシウム、ステ
アリン酸アンモニウムの中の一つ、または二以上の複合
体であることが好ましい。The temporary binder is preferably a stearic acid derivative, and the stearic acid derivative is one of stearic acid, stearic acid amide, aluminum stearate, magnesium stearate, and ammonium stearate. It is preferably one or two or more complexes.
【０００８】[0008]
【作用】本発明に係る成形体の製造方法では、複数の粉
粒体からなる原材料に液状添加剤および仮結合剤が加え
られると、この仮結合剤が前記液状添加剤と反応結合し
て該原材料の各粉粒体を囲繞する。このため、粉粒体の
見掛け上の粒子径が膨径し、この粉粒体自体が微粒子で
あっても成形装置のキャビテイに充填された際に金型ク
リアランスから漏洩することを有効に阻止することがで
きる。さらに、成形装置で一軸加圧成形または射出成形
する際、キャビテイを形成する壁面とパンチまたはプラ
ンジャーとの間隙に、原材料の各々の粉粒体がその頂点
や稜を架橋させた粉粒体ブリッジを形成し、次いで前記
粉粒体ブリッジの間隙より余分の液状添加剤を除去しつ
つ静水圧加圧状態を経て予備成形体が成形される。その
結果、均一な密度からなる予備成形体が得られる。In the method for producing a molded article according to the present invention, when a liquid additive and a temporary binder are added to a raw material composed of a plurality of powder particles, the temporary binder reacts with the liquid additive to form Surround each granule of raw material. Therefore, the apparent particle diameter of the powder or granules is expanded, and even if the powder or granules themselves are fine particles, they are effectively prevented from leaking from the mold clearance when they are filled in the cavity of the molding apparatus. be able to. Furthermore, when performing uniaxial pressure molding or injection molding with a molding device, a granular material bridge in which each agglomerate of the raw material has its vertices or ridges bridged in the gap between the wall forming the cavity and the punch or plunger. Then, the preform is molded through isostatic pressing while removing the excess liquid additive from the gap of the powdery-grain bridge. As a result, a preform having a uniform density can be obtained.
【０００９】[0009]
【実施例】本発明に係る成形体の製造方法について実施
例を挙げ、添付の図面を参照しながら以下詳細に説明す
る。The method for producing a molded article according to the present invention will be described in detail below with reference to the accompanying drawings.
【００１０】図１において、参照符号１０は、本実施例
に係る成形体の製造方法を実施するための成形装置を示
す。この成形装置１０は、金型１２を備え、この金型１
２に形成されたキャビテイ１４に下部パンチ１６と上部
パンチ１８とが一軸加圧可能に配設されており、前記キ
ャビテイ１４と下部パンチ１６および上部パンチ１８と
の間には、クリアランス１９が設けられている。実験例１ 実験例１に係る成形体の製造方法では、金型１２の寸法
を精密測定してクリアランス１９の最大値を求めるとと
もに、各種粉粒体を用意してその平均粒径と前記クリア
ランス１９からの粉粒体の流出の有無との関係を検出し
た。In FIG. 1, reference numeral 10 indicates a molding apparatus for carrying out the method for manufacturing a molded body according to this embodiment. The molding apparatus 10 includes a mold 12, and the mold 1
A lower punch 16 and an upper punch 18 are uniaxially pressurizable in a cavity 14 formed in 2, and a clearance 19 is provided between the cavity 14 and the lower punch 16 and the upper punch 18. ing. Experimental Example 1 In the method for manufacturing a molded body according to Experimental Example 1, the dimension of the mold 12 is precisely measured to obtain the maximum value of the clearance 19, and various powders and granules are prepared to obtain the average particle diameter and the clearance 19 described above. The relationship with the presence or absence of outflow of powder and granules was detected.
【００１１】そこで、まず、粉粒体の１００重量部に対
し、エチルアルコールが１７重量部、仮結合剤であるス
テアリン酸アンモニウムが０．０８重量部および０．１
０重量部ずつ添加された二種の混合物（原材料）２０を
得た。この二種の混合物２０をそれぞれ金型１２のキャ
ビテイ１４に充填し、クリアランス１９とこのクリアラ
ンス１９から流出する粉粒体の平均粒径との関係を実験
した。その結果が図２に示されている。Therefore, first, 17 parts by weight of ethyl alcohol and 0.08 parts by weight and 0.1 part of ammonium stearate as a temporary binder are used with respect to 100 parts by weight of the granular material.
Two kinds of mixtures (raw materials) 20 added by 0 parts by weight were obtained. The two mixtures 20 were filled in the cavities 14 of the mold 12, and the relationship between the clearance 19 and the average particle size of the powder or granules flowing out from the clearance 19 was tested. The result is shown in FIG.
【００１２】図２において、例えばクリアランス１９が
６０μｍであると、ステアリン酸アンモニウムの添加量
が０．０８重量部の場合に平均粒径が１．６μｍ以下の
粉粒体が流出してしまい、この流出を阻止するためには
１．６μｍ以上の平均粒径が必要となった。また、クリ
アランス１９が１２０μｍであると、ステアリン酸アン
モニウムの添加量が０．０８重量部の場合には平均粒径
が５．６μｍ以下の粉粒体が流出する一方、ステアリン
酸アンモニウムの添加量が０．１０重量部の場合には平
均粒径が２．４μｍ以上の粉粒体であれば流出せず、成
形可能であることが認められた。In FIG. 2, for example, when the clearance 19 is 60 μm, when the addition amount of ammonium stearate is 0.08 parts by weight, powder particles having an average particle diameter of 1.6 μm or less flow out. An average particle size of 1.6 μm or more was required to prevent outflow. Further, when the clearance 19 is 120 μm, when the amount of ammonium stearate added is 0.08 parts by weight, the powder having an average particle size of 5.6 μm or less flows out, while the amount of ammonium stearate added is In the case of 0.10 parts by weight, it was confirmed that powder particles having an average particle diameter of 2.4 μm or more did not flow out and could be molded.
【００１３】この場合、仮結合剤であるステアリン酸系
化合物を添加しない従来のものでは、クリアランス１９
の１／５〜１／１０までの平均粒径の粉粒体を使用する
ことによりこのクリアランス１９からの流出がなく成形
可能となっていた。これに対して、仮結合剤であるステ
アリン酸アンモニウムを０．０８重量部だけ添加したも
のでは、従来のものに比べて１／２０〜１／３５の平均
粒径の粉粒体で成形可能となり、さらにステアリン酸ア
ンモニウムを０．１０重量部だけ添加したものでは、従
来のものに比べて１／３０〜１／５０の平均粒径の粉粒
体で成形可能となった。In this case, in the case of the conventional one which does not add the stearic acid compound as the temporary binder, the clearance 19
By using a powder or granular material having an average particle diameter of 1/5 to 1/10, it was possible to mold without the outflow from the clearance 19. On the other hand, when only 0.08 parts by weight of ammonium stearate, which is a temporary binder, is added, it becomes possible to form a powder having an average particle diameter of 1/20 to 1/35 as compared with the conventional one. Further, when only 0.10 parts by weight of ammonium stearate was added, it became possible to mold with a powder or granule having an average particle diameter of 1/30 to 1/50 as compared with the conventional one.
【００１４】すなわち、図３に示すように、各粉粒体３
０の間隙に液状添加剤（エチルアルコール等）３２およ
び仮結合剤（ステアリン酸アンモニウム等）３４が加え
られると、この仮結合剤３４が前記液状添加剤３２と反
応して溶解層（反応層）３６が得られた。このため、仮
結合剤３４と液状添加剤３２とが溶解層３６を介して互
いに結合し、各粉粒体３０を囲繞してこの粉粒体３０の
見掛け上の粒子径が膨径した（図３中、二点鎖線参
照）。従って、粉粒体３０自体が微粒子であっても見掛
け上の粒子径が膨径し、クリアランス１９から漏洩する
ことを有効に阻止することができた。That is, as shown in FIG.
When a liquid additive (ethyl alcohol or the like) 32 and a temporary binder (ammonium stearate or the like) 34 are added to the gap of 0, the temporary binder 34 reacts with the liquid additive 32 to dissolve layer (reaction layer). 36 was obtained. For this reason, the temporary binder 34 and the liquid additive 32 are bonded to each other through the dissolution layer 36, surrounding each of the powder particles 30 and expanding the apparent particle diameter of the powder particles 30 (Fig. (3, see the chain double-dashed line). Therefore, even if the particles 30 themselves are fine particles, it is possible to effectively prevent the apparent particle diameter from expanding and leaking from the clearance 19.
【００１５】なお、ステアリン酸アンモニウムに代替し
てステアリン酸アミドを使用した際にも、ほぼ同一の結
果が得られた。実験例２ 実験例２に係る成形体の製造方法では、まず、イミド分
解法により得られた窒化珪素粉（平均粒径０．４μｍ）
が９０重量部、酸化第２セリウム（平均粒径１μｍ）が
７重量部、酸化ランタン（平均粒径１μｍ）が３重量部
からなる粉粒体の１００重量部に対し、微粉砕したステ
アリン酸アミド（仮結合剤）が０．０７重量部だけ添加
されてボールミルで十分に混合された。さらに、脱泡後
にこの混合粉体の１００重量部に対し水が２５重量部だ
け加えられて十分に混合され、混合物２０が得られた。When stearamide was used instead of ammonium stearate, almost the same results were obtained. Experimental Example 2 In the method for manufacturing a molded body according to Experimental Example 2, first, silicon nitride powder (average particle size 0.4 μm) obtained by the imide decomposition method was used.
Is 90 parts by weight, cerium oxide (average particle size 1 μm) is 7 parts by weight, and lanthanum oxide (average particle size 1 μm) is 3 parts by weight. Only 0.07 part by weight of (temporary binder) was added and mixed well in a ball mill. Further, after defoaming, 25 parts by weight of water was added to 100 parts by weight of the mixed powder and sufficiently mixed to obtain a mixture 20.
【００１６】この混合物２０が、図示しない射出成形機
に導入されて８０ＭＰａ〜２００ＭＰａの射出圧力で成
形され、φ（直径）２０×１００ｍｍの予備成形体を得
た。この予備成形体は、成形欠陥がなく、粉粒体が金型
から漏洩することもなく水分のみがこの金型から排出さ
れた。This mixture 20 was introduced into an injection molding machine (not shown) and molded at an injection pressure of 80 MPa to 200 MPa to obtain a preform of φ (diameter) 20 × 100 mm. This preform had no molding defects, and the powder and granules did not leak from the mold, and only moisture was discharged from the mold.
【００１７】この場合、混合物２０に射出成形法により
射出圧力が付与されると、この混合物２０を構成する粉
粒体と金型の壁面との摩擦抵抗の方が、粉粒体同士のそ
れよりも大きいために、前記粉粒体の流動性は、金型に
近い部分よりも中央部分の方が良好であった。従って、
混合物２０の縁部に最も大きな応力がかかり、粉粒体同
士の緻密化がこの縁部から開始され、加圧力の増加に伴
って該縁部と金型の壁面との間に、緻密化により連接し
た粉粒体が架橋してブリッジ部が形成された。In this case, when the injection pressure is applied to the mixture 20 by the injection molding method, the frictional resistance between the powder particles forming the mixture 20 and the wall surface of the mold is smaller than that between the powder particles. Therefore, the fluidity of the granular material was better in the central portion than in the portion close to the mold. Therefore,
The greatest stress is applied to the edge of the mixture 20, and the densification of the powder and granular materials is started from this edge, and the densification occurs between the edge and the wall surface of the mold as the pressing force increases. The linked powder particles were crosslinked to form a bridge portion.
【００１８】このブリッジ部により、混合物２０を構成
する粉粒体のキャビテイ外への流失が阻止され、また適
量残留した液状添加剤により静水圧加圧状態が継続さ
れ、前記混合物２０の全ての部分に均一な圧力が付与さ
れた。その際、余分な液状添加剤を排出しながら、静水
圧加圧状態を経て、弾性変形圧力範囲内の加圧力により
混合物２０の緻密化がさらに進行すると、予備成形体
は、どの部位においても均質な一定の密度となり、しか
も粉粒体が弾性変形域内にあるためにこの粉粒体間の間
隙も開気孔の状態が維持された。比較例１ 実験例２と同一の成分、同一の組成からなる粉粒体の１
００重量部に対し、分散剤としてアルギン酸アンモニウ
ムが０．００１重量部、結合剤としてアクリル樹脂エマ
ルジョンが０．０２重量部、水が４０重量部だけ加えら
れ、ボールミルで十分に混合された。さらに、脱泡後に
この混合粉体の１００重量部に対し水が２５重量部だけ
加えられて十分に混合され、混合物が得られた。The bridge portion prevents the powder and granules constituting the mixture 20 from flowing out of the cavity, and the hydrostatic pressure state is maintained by the liquid additive remaining in an appropriate amount, so that all the parts of the mixture 20 can be maintained. A uniform pressure was applied to the. At that time, while the excess liquid additive is discharged, the mixture 20 is hydrostatically pressurized, and the densification of the mixture 20 further progresses due to the pressing force within the elastic deformation pressure range. Since the density of the powder and granules was within a range of elastic deformation, the gaps between the powder and granules were maintained as open pores. Comparative Example 1 1 of the powder and granules having the same components and the same composition as in Experimental Example 2
To 100 parts by weight, 0.001 parts by weight of ammonium alginate as a dispersant, 0.02 parts by weight of an acrylic resin emulsion as a binder, and 40 parts by weight of water were added, and they were sufficiently mixed by a ball mill. Further, after defoaming, 25 parts by weight of water was added to 100 parts by weight of the mixed powder and sufficiently mixed to obtain a mixture.
【００１９】この混合物が、実験例２と同一の条件で射
出成形された。その際、射出圧力が所定の圧力まで上が
らず、金型合わせ面から混合物が漏れてしまい、成形不
能となった。なお、金型は二分割であり、金型合わせ面
の精密測定により、クリアランスの最大は、無加圧状態
で０．１ｍｍだけ生じていた。実験例３ 実験例３に係る成形体の製造方法では、まず、電解銅粉
（平均粒径１０μｍ）が９７．５重量％、クロム粉（粒
径１０μｍ）が２．５重量％からなる粉粒体の１００重
量部にエチルアルコールが１７重量部だけ加えられて十
分に混合されたもの（以下、混合物Ａという）、さらに
仮結合剤であるステアリン酸アミドが０．０３重量部〜
０．５重量部だけ添加されて十分に混合されたもの（以
下、混合物Ｂという）、ステアリン酸アンモニウム（仮
結合剤）が０．０３重量部〜０．５重量部だけ添加され
て十分に混合されたもの（以下、混合物Ｃという）、ス
テアリン酸（仮結合剤）が０．０３重量部〜０．５重量
部だけ添加されて十分に混合されたもの（以下、混合物
Ｄという）、ステアリン酸アルミニウム（仮結合剤）が
０．０３重量部〜０．５重量部だけ添加されて十分に混
合されたもの（以下、混合物Ｅという）、ステアリン酸
マグネシウム（仮結合剤）が０．０３重量部〜０．５重
量部だけ添加されて十分に混合されたもの（以下、混合
物Ｆという）を用意した。This mixture was injection molded under the same conditions as in Experimental Example 2. At that time, the injection pressure did not rise to a predetermined pressure, the mixture leaked from the mold mating surface, and molding became impossible. The mold was divided into two parts, and the maximum clearance was found to be 0.1 mm in the non-pressurized state by the precise measurement of the mold mating surface. Experimental Example 3 In the method for producing a molded body according to Experimental Example 3, first, 97.5% by weight of electrolytic copper powder (average particle size 10 μm) and 2.5% by weight of chromium powder (particle size 10 μm) are powder particles. 17 parts by weight of ethyl alcohol were added to 100 parts by weight of the body and mixed sufficiently (hereinafter referred to as mixture A), and stearic acid amide as a temporary binder was added in an amount of 0.03 parts by weight or more.
What was added well by mixing only 0.5 parts by weight (hereinafter referred to as mixture B), ammonium stearate (temporary binder) was added by 0.03 parts by weight to 0.5 parts by weight and mixed well. (Hereinafter referred to as mixture C), stearic acid (temporary binder) added in an amount of 0.03 to 0.5 parts by weight and thoroughly mixed (hereinafter referred to as mixture D), stearic acid Aluminum (temporary binder) added by 0.03 to 0.5 parts by weight and mixed well (hereinafter referred to as mixture E), magnesium stearate (temporary binder) 0.03 parts by weight. A mixture (hereinafter referred to as a mixture F) was prepared in which only about 0.5 parts by weight was added and thoroughly mixed.
【００２０】そして、上記混合物Ａ乃至Ｆがそれぞれ金
型１２のキャビテイ１４に充填され、一軸加圧成形法に
より１００ＭＰａの成形圧力で１２０×２４×２４ｍｍ
の予備成形体を得た。その結果が図４に示されている。
ここで、仮結合剤であるステアリン酸系化合物を加えず
エチルアルコールが添加された混合物Ａでは、抜き出し
圧力が約３ＭＰａ（３０．６ｋｇｆ／ｃｍ2 ）〜４ＭＰ
ａ（４０．７ｋｇｆ／ｃｍ2 ）であった。Then, the mixtures A to F are filled in the cavities 14 of the mold 12, respectively, and 120 × 24 × 24 mm at a molding pressure of 100 MPa by a uniaxial pressure molding method.
A preformed body of was obtained. The result is shown in FIG.
Here, in the mixture A to which ethyl alcohol was added without adding the stearic acid compound as the temporary binder, the extraction pressure was about 3 MPa (30.6 kgf / cm 2 ) to 4 MP.
It was a (40.7 kgf / cm 2 ).
【００２１】一方、エチルアルコールの他にステアリン
酸系化合物が添加されたもの（混合物Ｂ乃至Ｆ）では、
抜き出し圧力が急激に減少し、僅か０．３重量部の添加
量でもこの抜き出し圧力が１ＭＰａ（１０．２ｋｇｆ／
ｃｍ2 ）となった。なお、全ての予備成形体に成形欠陥
は認められなかった。On the other hand, in the case of adding a stearic acid compound in addition to ethyl alcohol (mixtures B to F),
The withdrawal pressure decreased sharply, and even with an addition amount of only 0.3 parts by weight, the withdrawal pressure was 1 MPa (10.2 kgf /
cm 2 ). No molding defects were found in any of the preforms.
【００２２】ここで、ステアリン酸系化合物の種類によ
る抜き出し圧力への影響が若干あるものの、０．５ＭＰ
ａ〜１ＭＰａの範囲であり、問題にはならなかった。ま
た、エチルアルコールを添加する代わりに、メチルアル
コール、ヘキサン、トルエンおよび塩化メチルを添加し
て実験を行ったところ、上記エチルアルコールの場合と
同様の結果が得られた。Here, although there is a slight effect on the extraction pressure depending on the type of stearic acid compound, 0.5MP
It was in the range of a to 1 MPa, which was not a problem. Further, when an experiment was conducted by adding methyl alcohol, hexane, toluene and methyl chloride instead of adding ethyl alcohol, the same result as in the case of the above ethyl alcohol was obtained.
【００２３】次に、得られた予備成形体が、窒素雰囲気
または真空下において６５０℃で３０分間だけ保持され
た後、１０００℃で１時間、さらに１０５０℃で２時間
ずつ保持され、冷却後に５００℃で４時間保持されて焼
成された。その結果が図５に示されている。なお、密度
の測定は、アルキメデス法によった。Next, the obtained preformed body was held at 650 ° C. for 30 minutes in a nitrogen atmosphere or vacuum, then at 1000 ° C. for 1 hour, and at 1050 ° C. for 2 hours each, and after cooling, 500 It was kept at 4 ° C. for 4 hours and baked. The result is shown in FIG. The density was measured by the Archimedes method.
【００２４】この場合、混合物Ｂ、Ｃにおいて、ステア
リン酸アミド、ステアリン酸アンモニウムの添加量が
０．１重量部以下のものは、相対密度が１００％であっ
た。また、混合物Ｄのステアリン酸の添加量が０．０６
重量部以下、混合物Ｅのステアリン酸アルミニウムの添
加量が０．０２重量部以下、混合物Ｆのステアリン酸マ
グネシウムの添加量が０．０２重量部以下のものは、相
対密度が１００％であった。比較例２ 実験例３と同一の成分、同一の組成からなる粉粒体の１
００重量部にステアリン酸亜鉛が０．５重量部だけ添加
され、通常の乾式成形法により予備成形体を得た。その
時の抜き出し圧力は、７ＭＰａとなった。また、全部の
予備成形体にラミネーションクラック等の成形欠陥が認
められた。In this case, in the mixtures B and C, stearic acid amide and ammonium stearate were added in an amount of 0.1 parts by weight or less, the relative density was 100%. Further, the addition amount of stearic acid in the mixture D was 0.06.
The relative density of 100 parts by weight or less, the addition amount of aluminum stearate of the mixture E of 0.02 parts by weight or less, and the addition amount of magnesium stearate of the mixture F of 0.02 parts by weight or less was 100%. Comparative Example 2 1 of powder and granular material having the same components and the same composition as in Experimental Example 3
0.5 parts by weight of zinc stearate was added to 00 parts by weight, and a preform was obtained by a usual dry molding method. The extraction pressure at that time was 7 MPa. In addition, molding defects such as lamination cracks were found in all the preformed products.
【００２５】一方、上記の粉粒体の１００重量部に、ジ
メチルケトンが１７重量部とステアリン酸エチルが０．
０３重量部〜０．５重量部だけ添加され、通常の乾式成
形法により予備成形体を得た。この予備成形体では、全
部に成形欠陥が認められなかったものの、抜き出し圧力
は、２．５ＭＰａ〜２．８ＭＰａとなった（図４参
照）。On the other hand, 100 parts by weight of the above powder and granules contained 17 parts by weight of dimethyl ketone and 0.
Only 0.3 parts by weight to 0.5 parts by weight was added, and a preform was obtained by a usual dry molding method. In this preform, although no forming defects were found in all, the extraction pressure was 2.5 MPa to 2.8 MPa (see FIG. 4).
【００２６】[0026]
【発明の効果】以上のように、本発明に係る成形体の製
造方法によれば、複数の粉粒体からなる原材料に液状添
加剤および仮結合剤が加えられると、この仮結合剤が前
記液状添加剤と反応結合して該原材料の各粉粒体を囲繞
する。このため、粉粒体の見掛け上の粒子径が膨径し、
この粉粒体自体が微粒子であっても成形装置のキャビテ
イに充填された際に金型クリアランスから漏洩すること
を有効に阻止することができる。さらに、成形装置で一
軸加圧成形または射出成形する際、キャビテイを形成す
る壁面とパンチまたはプランジャーとの間隙に、原材料
の各々の粉粒体がその頂点や稜を架橋させた粉粒体ブリ
ッジを形成し、次いで前記粉粒体ブリッジの間隙より余
分の液状添加剤を除去しつつ静水圧加圧状態を経て予備
成形体が成形される。その結果、均一な密度からなる予
備成形体が得られる。As described above, according to the method for producing a molded article of the present invention, when a liquid additive and a temporary binder are added to a raw material composed of a plurality of powder particles, the temporary binder is Reactively bond with the liquid additive to surround each powder of the raw material. For this reason, the apparent particle size of the granular material expands,
Even if the particles themselves are fine particles, it is possible to effectively prevent the particles from leaking from the mold clearance when they are filled in the cavity of the molding apparatus. Furthermore, when performing uniaxial pressure molding or injection molding with a molding device, a granular material bridge in which each agglomerate of the raw material has its vertices or ridges bridged in the gap between the wall forming the cavity and the punch or plunger. Then, the preform is molded through isostatic pressing while removing the excess liquid additive from the gap of the powdery-grain bridge. As a result, a preform having a uniform density can be obtained.
【図１】本実施例に係る成形体の製造方法に用いられる
成形装置の縦断面図である。FIG. 1 is a vertical cross-sectional view of a molding apparatus used in a method for manufacturing a molded body according to this example.
【図２】金型のクリアランスと流出する粉粒体の平均粒
径との関係を示す図である。FIG. 2 is a diagram showing a relationship between a clearance of a die and an average particle diameter of powder particles flowing out.
【図３】本実施例に係る成形体の製造方法の動作状態を
示す模式図である。FIG. 3 is a schematic diagram showing an operating state of the method for manufacturing a molded body according to the present embodiment.
【図４】種々の添加物の添加量と抜き出し圧力との関係
を示す図である。FIG. 4 is a diagram showing the relationship between the amount of various additives added and the extraction pressure.
【図５】種々の添加物の添加量と密度との関係を示す図
である。FIG. 5 is a diagram showing the relationship between the amount of various additives added and the density.
１０…成形装置 １２…金型 １４…キャビテイ １６…下部パンチ １８…上部パンチ １９…クリアランス ２０…混合物 ３０…粉粒体 ３２…液状添加剤 ３４…仮結合剤 ３６…溶解層 10 ... Molding device 12 ... Mold 14 ... Cavity 16 ... Lower punch 18 ... Upper punch 19 ... Clearance 20 ... Mixture 30 ... Granule 32 ... Liquid additive 34 ... Temporary binder 36 ... Melt layer
Claims (3)
剤および前記液状添加剤と反応結合して該原材料の各粉
粒体を囲繞する仮結合剤を加えて混合する第１工程と、 前記第１工程で得られた混合物を一軸加圧成形法または
射出成形法により余分の液状添加剤を除去して予備成形
体を得る第２工程と、 前記第２工程で得られた予備成形体を焼成して成形体を
得る第３工程と、 を備えることを特徴とする成形体の製造方法。1. A first step in which a raw material composed of a plurality of powders and granules is added with a liquid additive and a temporary binder which is reactively bound to the liquid additive and surrounds each powdery granule of the raw material. A second step of removing the excess liquid additive from the mixture obtained in the first step by a uniaxial pressure molding method or an injection molding method to obtain a preform, and the preforming obtained in the second step A third step of firing the body to obtain a molded body, the method for manufacturing a molded body.
結合剤は、ステアリン酸系誘導体であることを特徴とす
る成形体の製造方法。2. The method for producing a molded article according to claim 1, wherein the temporary binder is a stearic acid derivative.
テアリン酸系誘導体は、ステアリン酸、ステアリン酸ア
ミド、ステアリン酸アルミニウム、ステアリン酸マグネ
シウム、ステアリン酸アンモニウムの中の一つ、または
二以上の複合体であることを特徴とする成形体の製造方
法。3. The manufacturing method according to claim 2, wherein the stearic acid derivative is one of stearic acid, stearic acid amide, aluminum stearate, magnesium stearate, and ammonium stearate, or a composite of two or more thereof. A method for producing a molded article, which is a body.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP00407593A JP3420786B2 (en) | 1993-01-13 | 1993-01-13 | Manufacturing method of molded body |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP00407593A JP3420786B2 (en) | 1993-01-13 | 1993-01-13 | Manufacturing method of molded body |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH06212204A true JPH06212204A (en) | 1994-08-02 |
| JP3420786B2 JP3420786B2 (en) | 2003-06-30 |
Family
ID=11574692
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP00407593A Expired - Fee Related JP3420786B2 (en) | 1993-01-13 | 1993-01-13 | Manufacturing method of molded body |
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| Country | Link |
|---|---|
| JP (1) | JP3420786B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4493880B2 (en) * | 2001-05-17 | 2010-06-30 | 本田技研工業株式会社 | Manufacturing method of composite material |
-
1993
- 1993-01-13 JP JP00407593A patent/JP3420786B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4493880B2 (en) * | 2001-05-17 | 2010-06-30 | 本田技研工業株式会社 | Manufacturing method of composite material |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3420786B2 (en) | 2003-06-30 |
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