JP2005205805A - Powder injection-molding composition and its sintered body - Google Patents

Powder injection-molding composition and its sintered body Download PDF

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JP2005205805A
JP2005205805A JP2004016358A JP2004016358A JP2005205805A JP 2005205805 A JP2005205805 A JP 2005205805A JP 2004016358 A JP2004016358 A JP 2004016358A JP 2004016358 A JP2004016358 A JP 2004016358A JP 2005205805 A JP2005205805 A JP 2005205805A
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organic binder
bma
mma
powder
injection molding
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Tetsuo Shiraiwa
徹男 白岩
Yohei Nishida
洋平 西田
Hidetaka Uraoka
秀隆 浦岡
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Daiichi Seramo Kk
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Daiichi Seramo Kk
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Abstract

<P>PROBLEM TO BE SOLVED: To provide a powder injection-molding composition which increases the strength of a green molding, is excellent in defatting properties (binder removing properties) and sintering properties, and can obtain a sintered body minimizing deformation, cracking, and swelling. <P>SOLUTION: The powder injection-molding composition contains an acrylic resin of 50,000-300,000 weight average molecular weight containing an inorganic powder and an organic binder in a volume ratio (inorganic powder/organic binder) of 65/35-25/75. The organic binder is made of an n-butyl methacrylate (n-BMA)/methyl methacrylate (MMA) copolymer (n-BMA/MMA=30/70-70/30) and/or a mixture (n-BMA/MMA=30/70-70/30) of an n-BMA polymer and an MMA polymer. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

本発明は、粉末射出成形用組成物、及びその焼結体に関し、詳しくは無機粉末と有機バインダーとからなる粉末射出成形用組成物、及びその組成物を成形し焼結して得られた焼結体に関する。   The present invention relates to a composition for powder injection molding and a sintered body thereof, and more specifically, a composition for powder injection molding composed of an inorganic powder and an organic binder, and a sintered body obtained by molding and sintering the composition. Concerning union.

近年、自動車のエンジン部分のように、複雑形状の部品を工業的に大量に生産(製造)する方法として、次のような技術が採用されている。すなわち、セラミックス粉末(無機粉末)に有機バインダーを混合し、可塑性を付与し、射出成形することによってグリーン成形体を得、引き続き脱バインダーして焼成することによりセラミックス製品としている。   2. Description of the Related Art In recent years, the following technology has been adopted as a method for industrially producing (manufacturing) complicatedly shaped parts such as automobile engine parts. That is, an organic binder is mixed with ceramic powder (inorganic powder), plasticity is imparted, and a green molded body is obtained by injection molding, followed by debinding and firing to obtain a ceramic product.

ここで使用される有機バインダーは、セラミックス粉末の均一な分散性、混合物(組成物)の流動特性、グリーン成形体の強度、グリーン成形体からのバインダーの除去の容易さ(脱バインダー性)、及び当該混合物の焼結性などの物性に大きく関わる重要な要素となり、いくつかの技術が提案されている(例えば、特許文献1参照)。
特開平3−150257号公報
The organic binder used here is the uniform dispersibility of the ceramic powder, the flow characteristics of the mixture (composition), the strength of the green molded body, the ease of removal of the binder from the green molded body (debinding property), and It becomes an important factor greatly related to physical properties such as sinterability of the mixture, and several techniques have been proposed (see, for example, Patent Document 1).
JP-A-3-150257

上記の技術により、確かに優れた射出成形を行うことが可能となったが、本発明者は、従来の技術を改良して種々の性能を向上すべく、さらなる研究開発を進めた結果、特定のメタクリル酸エステルを組み合わせて得た共重合体あるいは重合体の混合物を含有する有機バインダーを特定の割合で以て無機粉末と混合することにより、グリーン成形体の強度、脱脂性などの物性が向上することを見い出し、そして本発明に至った。   Although the above technology has made it possible to perform excellent injection molding, the present inventor has conducted further research and development in order to improve the conventional technology and improve various performances. By mixing an organic binder containing a copolymer or a mixture of polymers obtained by combining methacrylic acid esters with inorganic powder at a specific ratio, the green molded body has improved physical properties such as strength and degreasing properties. And found the present invention.

請求項1に記載の粉末射出成形用組成物は、無機粉末と有機バインダーを含有してなる粉末射出成形用組成物であって、前記無機粉末/前記有機バインダーの割合が体積比で65/35〜25/75であり、前記有機バインダーが、n−ブチルメタクリレート(以下、単に「n−BMA」ともいう)とメチルメタクリレート(以下、単に「MMA」ともいう)の共重合体および/またはn−BMAの重合体とMMAの重合体との混合物からなる、重量平均分子量が5万〜30万のアクリル系樹脂を含有する。   The composition for powder injection molding according to claim 1 is a composition for powder injection molding comprising an inorganic powder and an organic binder, wherein the ratio of the inorganic powder / the organic binder is 65/35 by volume. 25/75, and the organic binder is a copolymer of n-butyl methacrylate (hereinafter also simply referred to as “n-BMA”) and methyl methacrylate (hereinafter also simply referred to as “MMA”) and / or n- It contains an acrylic resin having a weight average molecular weight of 50,000 to 300,000 consisting of a mixture of a BMA polymer and a MMA polymer.

請求項2に記載の組成物は、請求項1記載の組成物において、前記n−ブチルメタクリレートとメチルメタクリレートの割合が、重量比で、n−ブチルメタクリレート/メチルメタクリレート=30/70〜70/30であることを特徴とする。   The composition according to claim 2 is the composition according to claim 1, wherein the ratio of n-butyl methacrylate to methyl methacrylate is n-butyl methacrylate / methyl methacrylate = 30/70 to 70/30 by weight ratio. It is characterized by being.

請求項3に記載の焼結体は、請求項1または2記載の粉末射出成形用組成物を成形し、のち焼結して得られたものである。   The sintered body according to claim 3 is obtained by molding the powder injection molding composition according to claim 1 or 2 and then sintering.

本発明の粉末射出成形用組成物によれば強度に優れたグリーン成形体を得ることができる。また、この粉末射出成形用組成物を成形して焼結する際の、脱脂性(脱バインダー性)および焼結性にも優れているので、変形や割れ、膨れなどを防いだクォリティーの高い最終製品を得ることができる。   According to the composition for powder injection molding of the present invention, a green molded body having excellent strength can be obtained. In addition, since this powder injection molding composition is molded and sintered, it has excellent degreasing properties (debinding properties) and sinterability, so it has a high quality finish that prevents deformation, cracking, and swelling. You can get a product.

無機粉末
本発明で用いられる無機粉末としては、従来から有機バインダーとともに成形体が成形され、焼結部材とされる用途に使用されている無機粉末であれば特に限定はないが、粉末粒子形状が球形に近く、かつ平均粒径0.1〜50μm程度のものであることが好ましい。前記平均粒径が0.1μm未満であれば、相対的に粉末の比表面積が増大し、バインダーの使用量を増やしても多くの場合、射出成形に適した流動特性を有する混合物を得ることが困難になり、また射出成形が可能でも、そののち脱バインダー工程を円滑に行なうことが難しく、脱バインダー後の成形体が脆くなり、ハンドリングが困難となる傾向にある。一方、50μmを超えた粗い粒度の粉末の場合、グリーン成形体および脱バインダー後の成形体の強度が低下する傾向にある。なお、0.1〜20μm程度のものであることがさらに好ましく、1〜12μm程度のものであることがさらに好ましい。
Inorganic powder The inorganic powder used in the present invention is not particularly limited as long as it is an inorganic powder that has been conventionally used for applications in which a molded body is molded with an organic binder and used as a sintered member. It is preferably close to a sphere and has an average particle size of about 0.1 to 50 μm. If the average particle size is less than 0.1 μm, the specific surface area of the powder is relatively increased, and in many cases, a mixture having flow characteristics suitable for injection molding can be obtained even if the amount of binder used is increased. Even if injection molding is possible, it is difficult to perform the debinding step smoothly after that, and the molded body after debinding becomes fragile and handling tends to be difficult. On the other hand, in the case of a powder having a coarse particle size exceeding 50 μm, the strength of the green molded body and the molded body after debinding tends to decrease. In addition, it is more preferable that it is about 0.1-20 micrometers, and it is further more preferable that it is about 1-12 micrometers.

無機粉末の具体例としては、例えば純鉄、鉄−ニッケル、鉄−コバルト、ステンレススチール(JIS SUS 304L(平均粒径8.9μm)、JIS SUS 316L(平均粒径10.5μm))などの鉄系合金、タングステン、アルミニウム合金、銅、銅合金などの金属粉末、アルミナ、ジルコニア、チタン酸塩、フェライトなどの酸化物系セラミックス粉末、窒化珪素、窒化アルミニウム、窒化硼素などの窒化物系セラミックス粉末、炭化珪素、炭化チタン、炭化タングステンなどの炭化物系セラミックス粉末などのほか、チタンアルミニウム合金などの金属間化合物粉末、アパタイトなどのリン酸塩類の粉末など、さらに1〜50体積%の範囲で金属または金属以外の無機質の繊維、ウィスカなどを含有する粉末なども挙げられる。   Specific examples of the inorganic powder include iron such as pure iron, iron-nickel, iron-cobalt, and stainless steel (JIS SUS 304L (average particle size 8.9 μm), JIS SUS 316L (average particle size 10.5 μm)). Metal powders such as aluminum alloys, tungsten, aluminum alloys, copper and copper alloys, oxide ceramic powders such as alumina, zirconia, titanate and ferrite, nitride ceramic powders such as silicon nitride, aluminum nitride and boron nitride, In addition to carbide ceramic powder such as silicon carbide, titanium carbide and tungsten carbide, intermetallic compound powder such as titanium aluminum alloy, phosphate powder such as apatite, etc. Non-organic fibers, powders containing whiskers, etc. are also included

前記金属の繊維やウィスカの例としては、例えば鋼、ステンレス、アルミニウム、マグネシウム、ニッケル、チタン、ベリリウム、タングステン、モリブデン、ボロンなどの繊維やウィスカが挙げられ、また前記金属以外の無機質の繊維やウィスカの例としては、例えばアルミナ、ジルコニア、炭化珪素、炭化硼素、窒化珪素、窒化硼素、窒化アルミニウムなどの繊維やウィスカが挙げられる。   Examples of the metal fibers and whiskers include fibers and whiskers such as steel, stainless steel, aluminum, magnesium, nickel, titanium, beryllium, tungsten, molybdenum, and boron, and inorganic fibers and whiskers other than the metal. Examples of these include fibers and whiskers such as alumina, zirconia, silicon carbide, boron carbide, silicon nitride, boron nitride, and aluminum nitride.

有機バインダー
本発明で使用される有機バインダーは、n−BMAとMMAの共重合体、あるいはn−BMAの重合体とMMAの重合体の混合物を含有する。有機バインダーに含まれるこれら共重合体あるいは混合物の含有割合は特に限定するものではないが、10〜90重量%であることが好ましい。10重量%未満では、グリーン成形体の強度が不足するという問題が生じる可能性があり、90重量%を超える場合では、粉末射出成形用組成物の流動性が低く、射出成形が困難となる可能性がある。なお、有機バインダーに含まれる上記の共重合体あるいは混合物の含有割合の好ましい範囲は、20〜80重量%である。
Organic Binder The organic binder used in the present invention contains a copolymer of n-BMA and MMA, or a mixture of n-BMA polymer and MMA polymer. Although the content rate of these copolymers or a mixture contained in an organic binder is not specifically limited, It is preferable that it is 10 to 90 weight%. If it is less than 10% by weight, there is a possibility that the strength of the green molded body is insufficient. If it exceeds 90% by weight, the fluidity of the composition for powder injection molding is low, and injection molding may be difficult. There is sex. In addition, the preferable range of the content rate of said copolymer or mixture contained in an organic binder is 20 to 80 weight%.

上記した共重合体および重合体混合物の重量平均分子量は5万〜30万である。5万未満の場合、グリーン成形体の強度が不足する問題が生じ、30万を超える場合、粉末射出成形用組成物の流動性が低く、射出成形が困難となる。なお、重量平均分子量の好ましい範囲は7万〜20万である。   The above copolymer and polymer mixture have a weight average molecular weight of 50,000 to 300,000. If it is less than 50,000, there is a problem that the strength of the green molded body is insufficient, and if it exceeds 300,000, the fluidity of the composition for powder injection molding is low and injection molding becomes difficult. In addition, the preferable range of a weight average molecular weight is 70,000 to 200,000.

なお、n−BMAとMMAの共重合体における各単量体の配合割合、あるいはn−BMAの重合体とMMAの重合体混合物における配合割合としては特に限定はないが、n−BMA/MMA=30/70〜70/30であることが好ましい。n−BMAが30重量%未満(MMAが70重量%を超える)の場合は、粉末射出成形用組成物の流動性が低く、射出成形が困難になる可能性があり、n−BMAが70重量%を超える(MMAが30重量%未満)の場合はグリーン成形体の強度が不足するという問題が生じる可能性がある。   The blending ratio of each monomer in the copolymer of n-BMA and MMA or the blending ratio in the polymer mixture of n-BMA and MMA is not particularly limited, but n-BMA / MMA = It is preferable that it is 30 / 70-70 / 30. When n-BMA is less than 30% by weight (MMA is more than 70% by weight), the fluidity of the composition for powder injection molding is low, which may make injection molding difficult, and n-BMA is 70% by weight. If the content exceeds 50% (MMA is less than 30% by weight), there is a possibility that the green molded body has insufficient strength.

配合割合、その他
無機粉末と有機バインダーの割合に関しては、体積比で、無機粉末:有機バインダー=65〜25:35〜75である。なお、本明細書にいう体積比とは、Wpを無機粉末の重量、Dpを無機粉末の真比重、Wbを有機バインダーの重量、Dbを有機バインダーの真比重とした場合、次式により表される。

Figure 2005205805
Regarding the blending ratio and the ratio of other inorganic powder and organic binder, the volume ratio is inorganic powder: organic binder = 65-25: 35-75. The volume ratio referred to in this specification is expressed by the following formula when Wp is the weight of the inorganic powder, Dp is the true specific gravity of the inorganic powder, Wb is the weight of the organic binder, and Db is the true specific gravity of the organic binder. The
Figure 2005205805

これより無機粉末が多ければ(有機バインダーが少なければ)、射出成形用材料としての組成物の流動性が不足し、所望の形状に成形することが困難となるという問題が生じ、逆に無機粉末が少なければ(有機バインダーが多ければ)、成形品の密度が上がらず、焼成時における収縮が大きくなり、寸法精度を落とすばかりか、加熱分解により脱バインダーを行う場合、多量のガスの発生のため、成形体にクラック、フクレなどの欠陥の生じ易くなる。この体積比の好ましい範囲は、60〜30:40〜70である。   If there is more inorganic powder than this (if there are few organic binders), the fluidity of the composition as an injection molding material will be insufficient, and there will be a problem that it will be difficult to mold into a desired shape. If there is little (if there are many organic binders), the density of the molded product will not increase, shrinkage during firing will increase, dimensional accuracy will be lowered, and when debinding by thermal decomposition, a large amount of gas will be generated , Defects such as cracks and blisters are likely to occur in the molded body. The preferable range of this volume ratio is 60-30: 40-70.

有機バインダーには、本発明における上記共重合体および重合体混合物以外の成分として、例えばスチレン、α−メチルスチレン、p−メチルスチレン、ビニルスチレンなどのスチレン系単量体を重合したポリマー成分を含ませることができるが、有機バインダー中における割合が多くなれば、該バインダーとしての流動性が悪くなり、成形が困難となる傾向がある。従って、スチレン系単量体の使用割合は単量体全体の80重量%以下とすることが好ましい。また、アタクチックポリプロピレンを有機バインダーとして併用することも可能である。アタクチックポリプロピレンは、無機粉末と混合した場合、良好な流動性を示し、射出成形が容易で、ハンドリングに必要な充分な強度を有するグリーン成形体を製造することができるが、その反面、脱バインダー性に劣るという欠点を有しているので配合割合を制限して使用することが好ましい。   The organic binder includes a polymer component obtained by polymerizing a styrene monomer such as styrene, α-methylstyrene, p-methylstyrene, vinylstyrene, etc., as components other than the copolymer and polymer mixture in the present invention. However, if the ratio in the organic binder is increased, the fluidity as the binder is deteriorated and the molding tends to be difficult. Therefore, the proportion of the styrene monomer used is preferably 80% by weight or less of the whole monomer. It is also possible to use atactic polypropylene in combination as an organic binder. When atactic polypropylene is mixed with inorganic powder, it exhibits good fluidity, easy injection molding, and can produce a green molded body with sufficient strength necessary for handling. Therefore, it is preferable to use the composition in a limited proportion.

その他、重合開始剤(ベンゾイルパーオキサイド、ラウロイルパーオキサイド、t−ブチルパーオキシ−2−エチルヘキサネートなどの有機過酸化物、アゾビスイソブチロニトリル、アゾビスジメチルバレロニトリルなどのアゾ化合物など)、連鎖移動剤(n−ドデシルメルカプタン、t−オクチルメルカプタンのようなメルカプト化合物や、α−メチルスチレン二重体など)、分散剤(ポリビニルアルコール、ヒドロキシエチルセルロース、ポリビニルピロリドンなどの水溶性有機高分子化合物や、ヒドロキシアパタイト、ピロリン酸マグネシウムなどの水難溶性の微粒子を、アニオン界面活性剤と併用したものなど)、ワックス(パラフィンワックス、マイクロクリスタリンワックス、ポリエチレンワックス、ミツロウ、カルナウバワックス、モンタンワックスなど)を使用することができる。使用割合や使用方法としては従来公知の方法を採用すればよい。   In addition, polymerization initiators (benzoperoxide, lauroyl peroxide, organic peroxides such as t-butylperoxy-2-ethylhexanate, azo compounds such as azobisisobutyronitrile, azobisdimethylvaleronitrile, etc.) Chain transfer agents (mercapto compounds such as n-dodecyl mercaptan and t-octyl mercaptan, α-methylstyrene duplexes), dispersants (water-soluble organic polymer compounds such as polyvinyl alcohol, hydroxyethyl cellulose, and polyvinylpyrrolidone) , Hydroxyapatite, magnesium pyrophosphate and other water-insoluble fine particles combined with an anionic surfactant), wax (paraffin wax, microcrystalline wax, polyethylene wax, beeswax, carnauba wax) Vinegar, it is possible to use the montan wax, etc.). A conventionally known method may be adopted as a usage ratio or usage method.

本発明に係る粉末射出成形用組成物を用いた焼結部材の製造は、通常、以下のようにして行われるが、このような方法に限定されるものではない。   Production of a sintered member using the composition for powder injection molding according to the present invention is usually performed as follows, but is not limited to such a method.

まず、無機粉末と有機バインダーとを加圧ニーダーのような混練機で充分加熱混練し、有機バインダー中に無機粉末を均一に分散させたのち、適当な形状、たとえば粗粉砕物またはペレット状にし、射出成形用材料とする。   First, the inorganic powder and the organic binder are sufficiently heated and kneaded in a kneader such as a pressure kneader, and after the inorganic powder is uniformly dispersed in the organic binder, it is made into an appropriate shape, for example, a coarsely pulverized product or a pellet, It shall be an injection molding material.

次に、この材料を通常プラスチック成形で使用されている公知の装置および方法により射出成形し、所望形状の成形体とする。そののち、加熱分解などの方法で成形体より有機バインダーを除去し、適宜最適の温度および雰囲気で焼結する焼成することにより、所望形状の無機焼結体が得られる。   Next, this material is injection-molded by a known apparatus and method generally used in plastic molding to obtain a molded body having a desired shape. After that, the organic binder is removed from the molded body by a method such as thermal decomposition, and firing is performed by appropriately sintering at an optimum temperature and atmosphere to obtain an inorganic sintered body having a desired shape.

以下、本発明の具体例を挙げるが、本発明はこれによって限定されるものではない。   Hereinafter, although the specific example of this invention is given, this invention is not limited by this.

合成例1(n−BMAとMMAの共重合体の調製)
5リットルの反応器にn−BMAを600g、MMAを900g、及びn−ドデシルメルカプタン0.3gを加えて撹拌しながら75℃に昇温したのち、重合開始剤としてベンゾイルパーオキサイド2.4gとを加えて溶解した。
Synthesis Example 1 (Preparation of a copolymer of n-BMA and MMA)
In a 5-liter reactor, 600 g of n-BMA, 900 g of MMA, and 0.3 g of n-dodecyl mercaptan were added and the temperature was raised to 75 ° C. with stirring. Then, 2.4 g of benzoyl peroxide was used as a polymerization initiator. In addition, it was dissolved.

これに予め別に調合しておいたイオン交換水1840mlとポリビニルアルコール(PVA)の3%水溶液160mlとからなる分散剤水溶液を加えて撹拌して、[n−BMA]−[MMA]溶液を懸濁させた。ついで、チッ素置換したのち、80℃で3時間、100℃で2時間反応させて重合させたのち、冷却して取り出し、洗浄、乾燥した。   To this, a dispersion aqueous solution consisting of 1840 ml of ion-exchanged water and 160 ml of a 3% aqueous solution of polyvinyl alcohol (PVA) prepared separately was added and stirred to suspend the [n-BMA]-[MMA] solution. I let you. Next, after nitrogen substitution, the mixture was reacted at 80 ° C. for 3 hours and at 100 ° C. for 2 hours for polymerization, then cooled, taken out, washed and dried.

得られた共重合体の重量平均分子量は10万で、粒径0.3〜1mmの範囲にある球状粒子だった。この分子量の測定は、下記[表1]の条件で行った。

Figure 2005205805
The obtained copolymer had a weight average molecular weight of 100,000 and was spherical particles having a particle diameter of 0.3 to 1 mm. The molecular weight was measured under the conditions shown in [Table 1] below.
Figure 2005205805

同様の方法で、下記[表2]〜[表3]に記載した他の共重合体を得た。   In the same manner, other copolymers described in the following [Table 2] to [Table 3] were obtained.

合成例2(n−BMAとMMAの重合体混合物の調製)
まずn−BMAの重合体を調製した。すなわち、5リットルの反応器にn−BMAを1500gおよびn−ドデシルメルカプタン0.35gを加えて溶解したのち、撹拌しながら75℃に昇温し溶解し、さらにベンゾイルパーオキサイド4.8g、t−ブチルパーオキシベンゾエート0.25gを加えて溶解した。これに予め別に調合しておいたイオン交換水1840mlとポリビニルアルコール(PVA)の3%水溶液160mlとからなる80℃の分散剤水溶液を加えて撹拌し、懸濁せしめた。
Synthesis Example 2 (Preparation of a polymer mixture of n-BMA and MMA)
First, a polymer of n-BMA was prepared. That is, after adding 1500 g of n-BMA and 0.35 g of n-dodecyl mercaptan to a 5 liter reactor and dissolving, the mixture was heated to 75 ° C. with stirring and dissolved, and 4.8 g of benzoyl peroxide, t- 0.25 g of butyl peroxybenzoate was added and dissolved. To this, an aqueous dispersion of 80 ° C. composed of 1840 ml of ion-exchanged water and 160 ml of a 3% aqueous solution of polyvinyl alcohol (PVA) prepared separately was added and stirred for suspension.

次に、別途MMAの重合体を調製した。すなわち、5リットルの反応器にMMAを1500g、及びn−ドデシルメルカプタン0.35gを加えて溶解したのち、撹拌しながら75℃に昇温し溶解し、さらにベンゾイルパーオキサイド4.8g、t−ブチルパーオキシベンゾエート0.25gを加えて溶解した。これに予め別に調合しておいたイオン交換水1840mlとポリビニルアルコール(PVA)の3%水溶液160mlとからなる80℃の分散剤水溶液を加えて撹拌し、懸濁せしめた。ついで、チッ素置換したのち、80℃で5時間、110℃で2時間反応させて重合を完結させた。   Next, a MMA polymer was separately prepared. That is, after adding 1500 g of MMA and 0.35 g of n-dodecyl mercaptan to a 5 liter reactor and dissolving, the mixture was heated to 75 ° C. with stirring and dissolved, and 4.8 g of benzoyl peroxide and t-butyl were added. 0.25 g of peroxybenzoate was added and dissolved. To this, an aqueous dispersion of 80 ° C. composed of 1840 ml of ion-exchanged water and 160 ml of a 3% aqueous solution of polyvinyl alcohol (PVA) prepared separately was added and stirred for suspension. Then, after nitrogen substitution, the reaction was completed at 80 ° C. for 5 hours and at 110 ° C. for 2 hours to complete the polymerization.

両方の懸濁液を混合したのち、冷却し、水洗・乾燥して、粒径0.3〜1.0mmの範囲にある白色球状粒子をえた。重量平均分子量は10万である。   After both suspensions were mixed, the mixture was cooled, washed with water and dried to obtain white spherical particles having a particle size of 0.3 to 1.0 mm. The weight average molecular weight is 100,000.

比較合成例1(複合アクリル系樹脂:ESB−R)
5リットルの反応器にn−ブチルメタクリレート(BMA)700g、スチレン500gおよびn−ドデシルメルカプタン0.35gを加えて溶解したのち、撹拌しながらエチレン−酢酸ビニル共重合体(EVA)(ウルトラセン722、東ソー(株)製)300gを加えて75℃に昇温し溶解し、さらにベンゾイルパーオキサイド4.8g、t−ブチルパーオキシベンゾエート0.25gを加えて溶解した。
Comparative Synthesis Example 1 (Composite acrylic resin: ESB-R)
In a 5-liter reactor, 700 g of n-butyl methacrylate (BMA), 500 g of styrene and 0.35 g of n-dodecyl mercaptan were added and dissolved, and then ethylene-vinyl acetate copolymer (EVA) (Ultracene 722, 300 g of Tosoh Corp.) was added and heated to 75 ° C. to dissolve, and 4.8 g of benzoyl peroxide and 0.25 g of t-butyl peroxybenzoate were further added and dissolved.

これに予め別に調合しておいたイオン交換水1840mlとポリビニルアルコール(PVA)の3%水溶液160mlとからなる80℃の分散剤水溶液を加えて撹拌し、懸濁せしめた。ついで、チッ素置換したのち、80℃で5時間、110℃で2時間反応させて重合を完結させた。のち、冷却し、水洗・乾燥して、粒径0.3〜1.0mmの範囲にある白色球状粒子をえた。この重合体粒子のトルエン溶液、30℃での固有粘度[η]は0.70であり、重量平均分子量は30万であった。

Figure 2005205805
Figure 2005205805
To this, an aqueous dispersion of 80 ° C. composed of 1840 ml of ion-exchanged water and 160 ml of a 3% aqueous solution of polyvinyl alcohol (PVA) prepared separately was added and stirred for suspension. Then, after nitrogen substitution, the reaction was completed at 80 ° C. for 5 hours and at 110 ° C. for 2 hours to complete the polymerization. Thereafter, it was cooled, washed with water and dried to obtain white spherical particles having a particle size in the range of 0.3 to 1.0 mm. The intrinsic viscosity [η] at 30 ° C. of the polymer particles in a toluene solution was 0.70, and the weight average molecular weight was 300,000.
Figure 2005205805
Figure 2005205805

実施例1〜7および比較例1〜3
[表2]〜[表3]に記載した無機粉末100部に対し、各成分から構成される有機バインダーを同表に記載した割合で以て配合して加圧ニーダーで混練し、4×5×54(mm)の角柱状試験片を射出成形して得た。なお、前記有機バインダーは[表1]〜[表2]に記載の成分を、同表に記載の割合(%)で以て配合したものである。グリーン成形体の強度、脱脂性、及び焼結性を測定し、結果を[表1]〜[表2]に併記した。なお、各試験の測定方法は、次の通りである。
Examples 1-7 and Comparative Examples 1-3
An organic binder composed of each component is blended in the proportions described in the table with respect to 100 parts of the inorganic powder described in [Table 2] to [Table 3], and kneaded with a pressure kneader. 4 × 5 A square columnar test piece of × 54 (mm) was obtained by injection molding. In addition, the said organic binder mix | blends the component as described in [Table 1]-[Table 2] by the ratio (%) as described in the table. The strength, degreasing property, and sinterability of the green molded body were measured, and the results are also shown in [Table 1] to [Table 2]. In addition, the measuring method of each test is as follows.

グリーン成形体の強度(グリーン強度):3点曲げ試験を行った。すなわち、上記角柱状試験片をオートグラフにて支持治具の間隔を30mmとし、ロードセルを5mm/minのスピードで下げたときの最大強度を測定した。
最大強度が4.0kgf/cm以上の場合は○とし、最大強度が4kgf/cm未満の場合は×とした。
Strength of green molded body (green strength) : A three-point bending test was performed. That is, the maximum strength when the prismatic test piece was autographed with the interval between the support jigs set to 30 mm and the load cell was lowered at a speed of 5 mm / min was measured.
When the maximum strength was 4.0 kgf / cm 2 or more, “◯” was given, and when the maximum strength was less than 4 kgf / cm 2, “ X” was given.

脱脂性:23hパターン試験を行った。すなわち、脱脂炉にて、室温〜80℃:1時間、80℃〜200℃:15時間、200℃〜350℃:5時間、350℃〜420℃:1時間、420℃〜600℃:1時間のパターンで昇温した。
脱脂後にクラックが無い場合は○とし、脱脂後にクラックが有る場合は×とした。
Degreasing : 23h pattern test was conducted. That is, in a degreasing furnace, room temperature to 80 ° C: 1 hour, 80 ° C to 200 ° C: 15 hours, 200 ° C to 350 ° C: 5 hours, 350 ° C to 420 ° C: 1 hour, 420 ° C to 600 ° C: 1 hour The temperature was raised with the pattern.
When there was no crack after degreasing, it was marked as ◯, and when there was a crack after degreasing, it was marked as x.

焼結性:焼成炉にて、昇温速度100℃/hrで最高温度1350℃まで昇温し、1350℃で2時間キープするパターンで焼成した。
焼結後にクラックが無い場合は○とし、焼結後にクラックが有る場合は×とした。
Sinterability : In a firing furnace, the temperature was raised to a maximum temperature of 1350 ° C. at a rate of temperature increase of 100 ° C./hr and fired in a pattern of keeping at 1350 ° C. for 2 hours.
When there was no crack after sintering, it was marked as ◯, and when there was a crack after sintering, it was marked as x.

自動車のエンジン部分のように、変形や割れ、膨れなどを最小限に防いだクォリティーの高い複雑形状の部品を工業的に大量に生産(製造)する必要がある場合に、本発明の組成物やこれを焼結してなる焼結物を用いることができる。   When it is necessary to industrially produce (manufacture) a large number of high-quality, complicated parts that prevent deformation, cracking, swelling, etc. to a minimum, such as engine parts of automobiles, the composition of the present invention A sintered product obtained by sintering this can be used.

Claims (3)

無機粉末と有機バインダーを含有してなる粉末射出成形用組成物であって、
前記無機粉末/前記有機バインダーの割合が体積比で65/35〜25/75であり、
前記有機バインダーが、n−ブチルメタクリレートとメチルメタクリレートの共重合体および/またはn−ブチルメタクリレートの重合体とメチルメタクリレートの重合体との混合物からなる、重量平均分子量が5万〜30万のアクリル系樹脂を含有することを特徴とする粉末射出成形用組成物。
A powder injection molding composition comprising an inorganic powder and an organic binder,
The ratio of the inorganic powder / the organic binder is 65 / 35-25 / 75 by volume ratio,
The acrylic binder having a weight average molecular weight of 50,000 to 300,000, wherein the organic binder is a mixture of a copolymer of n-butyl methacrylate and methyl methacrylate and / or a polymer of n-butyl methacrylate and a polymer of methyl methacrylate. A powder injection molding composition comprising a resin.
前記n−ブチルメタクリレートとメチルメタクリレートの割合が、重量比で、
n−ブチルメタクリレート/メチルメタクリレート=30/70〜70/30であることを特徴とする請求項1記載の組成物。
The ratio of the n-butyl methacrylate and methyl methacrylate is a weight ratio,
2. The composition according to claim 1, wherein n-butyl methacrylate / methyl methacrylate = 30/70 to 70/30.
請求項1又は2記載の粉末射出成形用組成物を成形し、のち焼結して得られた焼結体。   A sintered body obtained by molding the powder injection molding composition according to claim 1 or 2 and then sintering.
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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015516019A (en) * 2012-05-11 2015-06-04 コミサリヤ・ア・レネルジ・アトミク・エ・オ・エネルジ・アルテルナテイブ Actinide powders and compositions filled with aromatic polymers and / or PMMA
WO2020003901A1 (en) * 2018-06-29 2020-01-02 第一セラモ株式会社 Composition for 3d printer
KR20230131300A (en) 2021-04-07 2023-09-12 아사히 가세이 가부시키가이샤 Molded body, method for producing molded body, and method for producing sintered body

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04265267A (en) * 1991-02-19 1992-09-21 Murata Mfg Co Ltd Ceramic forming binder
JPH0789768A (en) * 1993-09-24 1995-04-04 Asahi Glass Co Ltd Aluminum nitride green sheet
JP2000233975A (en) * 1999-02-16 2000-08-29 Nippon Shokubai Co Ltd Ceramic precursor composition, ceramic green sheet using same and its production
JP2002080282A (en) * 2000-06-29 2002-03-19 Murata Mfg Co Ltd Ceramics slurry composition and its manufacturing method

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04265267A (en) * 1991-02-19 1992-09-21 Murata Mfg Co Ltd Ceramic forming binder
JPH0789768A (en) * 1993-09-24 1995-04-04 Asahi Glass Co Ltd Aluminum nitride green sheet
JP2000233975A (en) * 1999-02-16 2000-08-29 Nippon Shokubai Co Ltd Ceramic precursor composition, ceramic green sheet using same and its production
JP2002080282A (en) * 2000-06-29 2002-03-19 Murata Mfg Co Ltd Ceramics slurry composition and its manufacturing method

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015516019A (en) * 2012-05-11 2015-06-04 コミサリヤ・ア・レネルジ・アトミク・エ・オ・エネルジ・アルテルナテイブ Actinide powders and compositions filled with aromatic polymers and / or PMMA
WO2020003901A1 (en) * 2018-06-29 2020-01-02 第一セラモ株式会社 Composition for 3d printer
JPWO2020003901A1 (en) * 2018-06-29 2021-03-11 第一セラモ株式会社 Composition for 3D printer
KR20230131300A (en) 2021-04-07 2023-09-12 아사히 가세이 가부시키가이샤 Molded body, method for producing molded body, and method for producing sintered body

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