JP2004181575A

JP2004181575A - Manufacturing method of resinoid bonded super-abrasive grain grinding wheel

Info

Publication number: JP2004181575A
Application number: JP2002351739A
Authority: JP
Inventors: Tsuyoshi Fujii; 剛志藤井; Kimihisa Watanabe; 公寿渡邊
Original assignee: Noritake Co Ltd
Current assignee: Noritake Co Ltd
Priority date: 2002-12-03
Filing date: 2002-12-03
Publication date: 2004-07-02

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a resinoid bonded super-abrasive grain brinding wheel which can easily form a relatively thin grinding wheel and is excellent in grinding performance and service life. <P>SOLUTION: The method includes: a mixing process P1 of mixing numerous super-abrasive grains and at least two kinds of fluidal resins with different hardening conditions; a first hardening process P3 of hardening part of the fluidal resins included in a fluidal material mixed during the mixing process P1; and a second hardening process P6 of hardening the residual fluidal resins included in a semi-hardened material part of which is hardened during the first hardening process P3. Thus the semi-hardened material which has experienced the first hardening process P3 is machined into a predetermined shape by a subsequent first cutting process P4 and a take-up process P5. Thereafter, it is hardened by the second hardening process P6, whereby even the relatively thin grinding wheel can be easily formed, the super-abrasive grains can be appropriately scattered in a grinding wheel structure, and necessary and sufficient heat resistance property can be imported to the wheel. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、多数の超砥粒が合成樹脂結合剤により相互に結合して形成された複数の砥石部が台金に固着されて成るレジノイド超砥粒ホイールの製造方法の改良に関する。
【０００２】
【従来の技術】
多数の超砥粒が所定の結合剤により相互に結合して形成された複数の砥石部が台金に固着されて成る超砥粒ホイールが各分野で研削加工に多用されている。かかる超砥粒ホイールの一態様として、椀状（カップ状）を成す台金の端縁部に上記複数の砥石部が固着されて成る所謂カップ型超砥粒ホイールが知られている（例えば、特許文献１を参照）。このカップ型超砥粒ホイールは、例えばシリコン、化合物半導体、ガラス、セラミックス、フェライト、水晶、石英、超硬合金等の硬質脆性材料の研磨加工に好適に用いられるものである。従来、かかる硬質脆性材料の研磨加工は、ワークと研磨定盤を摺接させつつその間に研磨粒子を含有するスラリ（泥漿）を供給して行うポリシング研磨加工が主流であったが、研磨加工に関与しない研磨粒子が多く不経済であることに加え、多量の廃棄物を生じさせることから、その代替技術としての上記カップ型超砥粒ホイールに期待がかけられている。
【０００３】
【特許文献１】
特開２００１−２１９３７７号公報
【０００４】
ところで、前記多数の砥粒を相互に結合させる結合剤としては、合成樹脂結合剤（レジンボンド）、ガラス質結合剤（ビトリファイドボンド）、金属質結合剤（メタルボンド）、及び電着（電鋳）等が挙げられるが、前記硬質脆性材料の研磨加工に際して、比較的剛性の高いガラス質結合剤、金属質結合剤、及び電着ではスクラッチ等の不具合を発生させる可能性が高いことから、通常、比較的剛性の低い合成樹脂結合剤が用いられる。
【０００５】
【発明が解決しようとする課題】
しかし、一般によく知られた粉体フェノール等の粉体樹脂を結合剤としたレジノイド超砥粒ホイールでは、その粉体樹脂の平均径が３０μｍ程度と比較的大きいことから、例えば平均粒径１０μｍ以下といった比較的微細な超砥粒を用いた場合、それら多数の超砥粒が好適に分散されず、所望の研磨性能が得られないという弊害があった。そこで、液体フェノール等の流動性樹脂を結合剤とすることが考えられるが、かかる流動性樹脂は揮発成分を多分に含んでいるため、成形に際して反りや変形が生じ易く実用には適さない。よって、粉体樹脂と流動性樹脂とを混合させた合成樹脂結合剤を用いることが多いが、それでも超砥粒の分散性及び成形性が若干犠牲になり、更には耐熱性に劣る合成樹脂結合剤では研磨加工時の発熱によって耐用寿命が短くなるという弊害を有していた。とりわけ、前記砥石部が管状（パイプ状）又は部分円筒状といった比較的薄手の肉厚（厚さ寸法）を備えている場合その形成は難しく、研磨性能及び耐用寿命の向上には限界があった。
【０００６】
本発明は、以上の事情を背景として為されたものであり、その目的とするところは、比較的薄手の肉厚を備えた砥石部を容易に成形できる、研磨性能及び耐用寿命に優れたレジノイド超砥粒ホイールの製造方法を提供することにある。
【０００７】
【課題を解決するための手段】
かかる目的を達成するために、本発明の要旨とするところは、多数の超砥粒が合成樹脂結合剤により相互に結合して形成された複数の砥石部が台金に固着されて成るレジノイド超砥粒ホイールの製造方法であって、前記多数の超砥粒と前記合成樹脂結合剤の原料として硬化条件の異なる少なくとも２種類の流動性樹脂とを混合する混合工程と、その混合工程により混合された流動性原料に含まれる前記流動性樹脂の一部を硬化させる第１硬化工程と、その第１硬化工程により一部が硬化した半硬化原料に含まれる前記流動性樹脂の残部を硬化させる第２硬化工程とを含むことを特徴とするものである。
【０００８】
【発明の効果】
このようにすれば、前記多数の超砥粒と前記合成樹脂結合剤の原料として硬化条件の異なる少なくとも２種類の流動性樹脂とを混合する混合工程と、その混合工程により混合された流動性原料に含まれる前記流動性樹脂の一部を硬化させる第１硬化工程と、その第１硬化工程により一部が硬化した半硬化原料に含まれる前記流動性樹脂の残部を硬化させる第２硬化工程とを含むことから、前記第１硬化工程を経た半硬化原料を、続く工程において所定の形状に加工した後、前記第２硬化工程において本硬化させることで、比較的薄手の砥石部であっても成形が容易であることに加え、前記砥石部の砥石組織内に前記超砥粒を好適に分散させることができ、更に例えば熱硬化性樹脂を含むことでその砥石部に必要十分な耐熱性を付与できる。すなわち、比較的薄手の肉厚を備えた砥石部を容易に成形できる、研磨性能及び耐用寿命に優れたレジノイド超砥粒ホイールの製造方法を提供することができる。
【０００９】
【発明の他の態様】
ここで、好適には、前記流動性樹脂は、光硬化性樹脂と熱硬化性樹脂とを含むものである。このようにすれば、前記第１硬化工程にて前記光硬化性樹脂を硬化させた半硬化原料を、続く工程において所定の形状に加工した後、前記第２硬化工程にて前記熱硬化性樹脂を硬化させることで、比較的薄手の砥石部であっても成形が容易であることに加え、その砥石部に必要十分な耐熱性を付与できるという利点がある。
【００１０】
また、好適には、前記流動性樹脂は、硬化温度の異なる少なくとも２種類の熱硬化性樹脂を含むものである。このようにすれば、前記第１硬化工程にて比較的硬化温度の低い熱硬化性樹脂を硬化させた半硬化原料を、続く工程において所定の形状に加工した後、前記第２硬化工程にて比較的硬化温度の高い熱硬化性樹脂を硬化させることで、比較的薄手の砥石部であっても成形が容易であることに加え、その砥石部に必要十分な耐熱性を付与できるという利点がある。
【００１１】
また、好適には、前記流動性樹脂は、ラジカル重合性樹脂及び／又はカチオン重合性樹脂を含むものであり、更に好適には、アクリル樹脂及び／又はエポキシ樹脂を含むものである。このようにすれば、前記流動性樹脂として、例えばアクリル酸エステル等のラジカル重合性樹脂と、エポキシ樹脂等のカチオン重合性樹脂とを用いることで、前記第１硬化工程にて光ラジカル重合反応によりアクリル樹脂を硬化させた半硬化原料を、続く工程において所定の形状に加工した後、前記第２硬化工程にて熱カチオン重合反応によりエポキシ樹脂部分を硬化させることで、比較的薄手の砥石部であっても成形が容易であることに加え、その砥石部に必要十分な耐熱性を付与できるという利点がある。
【００１２】
また、好適には、前記流動性樹脂に含まれるラジカル重合性樹脂の割合は、５０重量％以上９５重量％以下の範囲内である。このようにすれば、前記第１硬化工程において光ラジカル重合反応によりアクリル樹脂が硬化することで、好適に形状変形可能な必要十分な硬さを有する半硬化原料が得られるという利点がある。なお、前記流動性樹脂に含まれるラジカル重合性樹脂の割合が５０重量％より小さい場合には前記半硬化原料の硬さが不十分となる一方、９５重量％より大きい場合には前記半硬化原料が硬くなり過ぎ、何れの場合も形状変形が困難となる。
【００１３】
また、好適には、前記レジノイド超砥粒ホイールは、椀状を成す台金の端縁部にそれぞれ管状を成す前記複数の砥石部が固着されて成るものである。このようにすれば、管状を成す砥石部の環状端部がワークの被加工面に好適に食い込むことで、前記超砥粒の平均粒径が比較的微細であっても優れた切れ味を示すレジノイド超砥粒ホイールを製造できるという利点がある。
【００１４】
また、好適には、前記管状を成す砥石部は、２ｍｍφ以上２０ｍｍφ以下の外径寸法と、２ｍｍ以上２０ｍｍ以下の高さ寸法と、０．０５ｍｍｔ以上３ｍｍｔ以下の径方向厚さ寸法とを備えたものであり、更に好適には、０．５ｍｍ以上５０ｍｍ以下の相互間隔で前記台金に固着されたものである。このようにすれば、前記砥石部の環状端部がワークの被加工面に更に好適に食い込むという利点がある。
【００１５】
また、好適には、前記管状を成す砥石部は、前記超砥粒の平均粒径、結合度、及び／又は集中度の異なる少なくとも２種類の超砥粒層がその径方向に積層されて形成されたものである。このようにすれば、例えば摩耗し難いが研磨性能に劣る第１超砥粒層と、摩耗し易いが研磨性能に優れた第２超砥粒層とを交互に積層することで、前記砥石部延いては前記レジノイド超砥粒ホイールの研磨性能及び耐用寿命を更に向上させることができるという利点がある。
【００１６】
また、好適には、前記レジノイド超砥粒ホイールは、椀状を成す台金の端縁部にそれぞれ部分円筒状を成す前記複数の砥石部が固着されて成るものである。このようにすれば、部分円筒状を成す砥石部の弧状端部がワークの被加工面に好適に食い込むことで、前記超砥粒の平均粒径が比較的微細であっても優れた切れ味を示すレジノイド超砥粒ホイールを製造できるという利点がある。
【００１７】
また、好適には、前記混合工程は、その平均粒径が前記超砥粒の平均粒径の８０％以下である球状の充填材を、その超砥粒と充填材とを合わせて前記流動性樹脂の３体積％以上１００体積％以下の範囲内となるように混合するものである。このようにすれば、前記砥石部の砥石組織内に、前記超砥粒を更に好適に分散させられるという利点がある。
【００１８】
また、好適には、前記超砥粒の平均粒径は、０．５μｍ以上１０μｍ以下の範囲内であり、前記充填材の平均粒径は、０．１μｍ以上１μｍ以下の範囲内である。このようにすれば、硬質脆性材料を更に好適に研磨加工し得るレジノイド超砥粒ホイールを製造できるという利点がある。
【００１９】
【実施例】
以下、本発明の好適な実施例を図面に基づいて詳細に説明する。
【００２０】
図１は、本発明の一実施例であるレジノイド超砥粒ホイールの製造方法が適用されたレジノイド超砥粒ホイール（以下、単に超砥粒ホイールと称する）１０を示す斜視図である。この図１に示すように、かかる超砥粒ホイール１０は、例えばスチール又はアルミニウム合金等の金属材料、或いはエンジニアリングプラスチック等の合成樹脂材料から成り外径２５０ｍｍφ程度の椀状（カップ状）を成す台金１２と、その台金１２の端縁部（環状面）１４に固着されたそれぞれ管状（パイプ状）を成す複数（図１では３４個）の砥石部１６とから構成されている。また、上記台金１２の底部中央には、研磨加工に際して図示しない所定の研磨装置の回転主軸に取り付けられるための取付穴１８が貫通して設けられている。
【００２１】
上記砥石部１６は、例えばダイヤモンド質又はＣＢＮ質等から成り平均粒径が０．５μｍ以上１０μｍ以下の範囲内である多数の超砥粒が、後述する所定の合成樹脂結合剤により相互に結合して形成されたものである。また、好適には、平均粒径が上記超砥粒の平均粒径の８０％以下すなわち０．１μｍ以上１μｍ以下の範囲内であるシリカ質又はアルミナ質等から成る球状の充填材（フィラ）を含有するものである。図２は、かかる砥石部１６を拡大して示す斜視図である。この図２に示すように、上記砥石部１６は、好適には、２ｍｍφ以上２０ｍｍφ以下の外径寸法Ｒと、２ｍｍ以上２０ｍｍ以下の高さ寸法ｈと、０．０５ｍｍｔ以上３ｍｍｔ以下の径方向厚さ寸法ｔとを備えたものであり、更に好適には、０．５ｍｍ以上５０ｍｍ以下の相互間隔で前記台金１２に例えばエポキシ樹脂系接着剤等により固着されたものである。
【００２２】
以上のように構成された前記超砥粒ホイール１０は、前記取付穴１８において所定の研磨装置の回転主軸に同軸となるように取り付けられ、その軸心Ｓまわりに回転駆動させられることで、前記砥石部１６の環状端部２０により研磨作用面が構成され、その研磨作用面により図示しないワークを研磨加工する所謂平面研磨用カップ型ホイールである。この超砥粒ホイール１０は、好適には、例えばシリコン、化合物半導体、ガラス、セラミックス、フェライト、水晶、石英、超硬合金等の硬質脆性材料の研磨加工に用いられるものである。
【００２３】
図３は、本発明の一実施例であるレジノイド超砥粒ホイールの製造方法を説明する工程図である。この図３に示すように、先ず、混合工程Ｐ１において、前記多数の超砥粒と前記合成樹脂結合剤の原料である流動性樹脂とが混合・撹拌されて流動性（ペースト状）原料とされる。この合成樹脂結合剤の原料である流動性樹脂は、硬化条件（架橋条件）の異なる少なくとも２種類の流動性樹脂から成るものであり、例えば光硬化性樹脂と熱硬化性樹脂とを含むもの、或いは硬化温度の異なる少なくとも２種類の熱硬化性樹脂を含むものである。この混合工程Ｐ１においては、必要に応じて所定のカチオン重合触媒等が添加される。
【００２４】
ここで、好適には、上記流動性樹脂は、ラジカル重合性樹脂及び／又はカチオン重合性樹脂を含むものであり、更に好適には、アクリル樹脂及び／又はエポキシ樹脂を含むものである。具体的には、硬化温度の異なる少なくとも２種類のカチオン重合性樹脂例えば環状脂肪族エポキシ樹脂及びグリシジルエーテル樹脂を含むものである。これらは何れも熱硬化性樹脂であるが、カチオン重合性に優劣を有していることで硬化温度が異なる。すなわち、比較的カチオン重合性に優れた環状脂肪族エポキシ樹脂の硬化温度は１２０℃程度であり、比較的カチオン重合性に劣るグリシジルエーテル樹脂の硬化温度は１８０℃程度である。
【００２５】
また、好適には、前記混合工程Ｐ１において、前記流動性樹脂に対する超砥粒の割合が３体積％以上１００体積％以下、前記流動性原料全体に対する流動性樹脂の割合が５０体積％以上９５体積％以下となるように、投入される原料の体積割合が予め定められる。また、必要に応じて前記流動性樹脂に対して１体積％以上９７体積％以下の前記充填材が適宜添加される。すなわち、好適には、前記超砥粒と充填材とを合わせて前記流動性樹脂の３体積％以上１００体積％以下の範囲内とされる。
【００２６】
前記混合工程Ｐ１にて混合・撹拌された前記流動性原料は、続く圧延工程Ｐ２において、圧延加工されることで薄手板状に形成される。具体的には、剥離剤による表面処理が施された厚さ５０μｍｔ程度の１対のＰＥＴシート相互間に、１０ｇ程度の前記流動性原料が挟み入れられて圧延加工されることで、表面積２５０ｍｍ^２×厚さ２００μｍｔ程度に引き延ばされる。
【００２７】
上記圧延工程Ｐ２にて薄手板状に引き延ばされた流動性原料には、続く第１硬化工程Ｐ３において、所定の第１温度Ｔ_１により熱処理が施され、前記流動性樹脂の一部が硬化させられて半硬化原料とされる。具体的には、１２０℃程度の第１温度Ｔ_１にて１時間保持の熱処理が施されることで、前記流動性原料に含まれる環状脂肪族エポキシ樹脂が硬化させられ、所定の定形性を有しつつも切断・曲げ等の変形が容易な厚さ２００μｍｔ程度の薄手板状の半硬化原料とされる。ここで、前記流動性原料に含まれるグリシジルエーテル樹脂は比較的カチオン重合性に劣ることから、上記第１温度Ｔ_１にて１時間保持といった比較的低温・短時間の熱処理では硬化されないのである。
【００２８】
上記第１硬化工程Ｐ３にて前記流動性樹脂の一部が硬化させられた半硬化原料は、前記ＰＥＴシートから剥離させられた後、続く第１切断工程Ｐ４において、例えば２０ｍｍ×７５ｍｍ程度の矩形状に切断される。更に続く巻取工程Ｐ５において、例えば４ｍｍφ×２０ｍｍ程度の円柱状樹脂材に１０ｍｍ程度ずらして巻き取られる。
【００２９】
上記巻取工程Ｐ５にて円柱状樹脂材に巻き取られた半硬化原料には、続く第２硬化工程Ｐ６において、所定の第２温度Ｔ_２により熱処理が施され、前記流動性樹脂の残部すなわち前記半硬化原料に含まれる流動性樹脂の略全てが硬化させられる。具体的には、１８０℃程度の第２温度Ｔ_２にて３時間保持の熱処理が施されることで、前記流動性原料に含まれるグリシジルエーテル樹脂が硬化させられた後、続く第２切断工程Ｐ７において、上記円柱状樹脂から引き抜かれて所定の長さ寸法に切断されることにより、図２に示すような砥石部１６として形成される。
【００３０】
以上のようにして形成された前記複数の砥石部１６が、固着工程Ｐ８において、前記台金１２の端縁部１４に例えばエポキシ樹脂系接着剤等により固着された後、仕上工程Ｐ９において、所定の切削加工等により形状が整えられることで、図１に示すような超砥粒ホイール１０が製造される。
【００３１】
前述の混合工程Ｐ１において混合される前記流動性樹脂は、光硬化性樹脂と熱硬化性樹脂とを含むもの例えば光硬化性を示すラジカル重合性樹脂及び熱硬化性を示すカチオン重合性樹脂を含むものであってもよい。具体的には、アクリル酸エステル等のラジカル重合性樹脂及びエポキシ樹脂等のカチオン重合性樹脂等が好適に用いられる。この場合、前記第１硬化工程Ｐ３にて光ラジカル重合反応によりアクリル樹脂が、前記第２硬化工程Ｐ６にて熱カチオン重合反応によりエポキシ樹脂部分がそれぞれ硬化させられる。また、好適には、前記流動性樹脂に含まれるラジカル重合性樹脂の割合は、５０重量％以上９５重量％以下の範囲内とされる。この割合が５０重量％より小さい場合には後述する前記第１硬化工程Ｐ３にて光ラジカル重合反応によりアクリル樹脂が硬化させられた半硬化原料の硬さが不十分となる一方、９５重量％より大きい場合にはその半硬化原料が硬くなり過ぎ、何れの場合も形状変形が困難となる。
【００３２】
また、前記混合工程Ｐ１乃至第１硬化工程Ｐ３において、前記超砥粒の平均粒径、結合度、及び／又は集中度の異なる少なくとも２種類の半硬化原料が形成され、前記巻取工程Ｐ５において、それら複数種類の半硬化原料が交互に巻き取られることで、例えば図４に示すように、前記超砥粒の平均粒径、結合度、及び／又は集中度の異なる少なくとも２種類の超砥粒層がその径方向に積層されて形成された砥石部２２を形成するものであってもよい。前記超砥粒の平均粒径が比較的小さい、結合度が比較的高い、及び／又は集中度が比較的低い第１超砥粒層２４は、摩耗し難いが研磨性能に劣る一方、超砥粒の平均粒径が比較的大きい、結合度が比較的低い、及び／又は集中度が比較的高い第２超砥粒層２６は、摩耗し易いが研磨性能に優れたものとなる。そのように、前記超砥粒の平均粒径、結合度、及び／又は集中度の異なる少なくとも２種類の超砥粒層がその径方向に積層されて形成された砥石部２２では、上記第１超砥粒層２４が設けられていることにより研磨加工に際して摩耗し難くなると共に、上記第２超砥粒層２６が設けられていることにより優れた切れ味が保証されるのである。
【００３３】
また、図５は、本発明のレジノイド超砥粒ホイールの製造方法が適用された他の一例である超砥粒ホイール３０を示す斜視図である。この図３に示すように、本実施例の超砥粒ホイール３０は、椀状を成す台金３２の端縁部にそれぞれ部分円筒状を成す複数（図５では１２枚）の砥石部３４が円筒状（リング状）に配列された状態で固着されて成る所謂平面研磨用カップ型ホイールであってもよい。この砥石部３４は、前記超砥粒ホイール１０に備えられた砥石部１６と同様に、前記多数の超砥粒と前記合成樹脂結合剤の原料として硬化条件の異なる少なくとも２種類の流動性樹脂とが混合させられ、第１温度Ｔ_１にてその流動性樹脂の一部が硬化させられた半硬化原料が切断及び変形され、第２温度Ｔ_２にてその半硬化原料に含まれる前記流動性樹脂の残部が硬化させられることで、例えば０．０５ｍｍｔ以上３ｍｍｔ以下の径方向厚さ寸法を備えて成形され、上記台金３２から１０ｍｍ程度突き出されて設けられたものである。かかる砥石部３４が設けられた超砥粒ホイール３０によっても、前述の硬質脆性材料を好適に研磨加工できる。
【００３４】
［実験例］
以下、本発明の効果を検証するために本発明者等が行った研磨試験について説明する。本発明者等は、先ず、平均粒径５μｍのダイヤモンド砥粒を３１．２５体積％と、平均粒径０．６μｍの球状アルミナを３．７５体積％と、カーボンブラックを２．５体積％と、合成樹脂結合剤を６２．５体積％とを原料として形成された外径６ｍｍφ×内径４ｍｍφ×高さ５ｍｍ程度の寸法を備えた管状の砥石部１６が固着されて成る実施例試料１と、平均粒径３μｍのダイヤモンド砥粒を３１．２５体積％と、平均粒径０．６μｍの球状アルミナを３．７５体積％と、カーボンブラックを２．５体積％と、合成樹脂結合剤を６２．５体積％とを原料として形成された上記実施例試料１と同程度の寸法を備えた管状の砥石部１６が固着されて成る実施例試料２と、上記実施例試料１と同様の原料から形成された厚さ３ｍｍｔ程度の寸法を備えた砥石部３４が台金３２から５ｍｍ程度突き出された状態で固着されて成る実施例試料３と、上記実施例試料２と同様の原料から形成された上記実施例試料３と同程度の厚さ寸法を備えた砥石部３４が台金３２からその実施例試料３と同程度突き出された状態で固着されて成る実施例試料４とを製造した。ここで、上記カーボンブラックとしては、ケッチェン・ブラック・インターナショナル（株）製のケッチェン・ブラックを、上記合成樹脂結合剤としては、ダイセル化学工業（株）製のセロキサイド２０２１Ｐを４０体積部と、同社製のＥＨＰＥ−３１５０ＣＥを５０体積部と、ナガセケムテックス（株）製のデナコールＥＸ−２５２を１０体積部と、カチオン重合開始剤である三新化学工業（株）のサンエイドＳＩ−１１０Ｌを３体積部とを混合して用いた。
【００３５】
以上のように構成された実施例試料１乃至４と、平均粒径５μｍ程度のダイヤモンド砥粒がガラス質結合剤により結合されて形成された上記実施例試料１及び２と同程度の寸法を備えた管状の砥石部が固着されて成る比較例試料１と、平均粒径３μｍ程度のダイヤモンド砥粒がガラス質結合剤により結合されて形成された上記実施例試料１及び２と同程度の寸法を備えた管状の砥石部が固着されて成る比較例試料２とを用いて研磨試験を行った。以下にその試験条件及び試験結果を示す。
【００３６】
［試験条件］
砥石外径：２５０ｍｍφ
研磨装置：平面研削盤
砥石周速：２０００ｍ／ｍｉｎ
切込速度：２０μｍ／ｍｉｎ
切込み量：トータル４０μｍ
ワーク材質：単結晶シリコンウェハ
研磨液：純水

【００３７】
この試験結果から明らかなように、本発明の一実施例である実施例試料１乃至４は、超砥粒であるダイヤモンド砥粒の粒径が比較的大きな５μｍ程度であると比較的微細な３μｍ程度であるとを問わず、切れ味・ワーク面品位共に優れている。一方、従来技術により製造された比較例試料１及び２では十分なワーク面品位が得られず、正常な研磨加工を行うことができないことが確認された。すなわち、本発明の適用された超砥粒ホイールによれば、従来の超砥粒ホイールでは不可能だった単結晶シリコンウェハのような硬質脆性材料の研磨加工を好適に行い得ることが検証された。
【００３８】
このように、本実施例によれば、前記多数の超砥粒と前記合成樹脂結合剤の原料として硬化条件の異なる少なくとも２種類の流動性樹脂とを混合する混合工程Ｐ１と、その混合工程Ｐ１により混合された流動性原料に含まれる前記流動性樹脂の一部を硬化させる第１硬化工程Ｐ３と、その第１硬化工程Ｐ３により一部が硬化した半硬化原料に含まれる前記流動性樹脂の残部を硬化させる第２硬化工程Ｐ６とを含むことから、前記第１硬化工程Ｐ３を経た半硬化原料を、続く第１切断工程Ｐ４及び巻取工程Ｐ５において所定の形状に加工した後、前記第２硬化工程Ｐ６において本硬化させることで、比較的薄手の砥石部１６であっても成形が容易であることに加え、その砥石部１６の砥石組織内に前記超砥粒を好適に分散させることができ、更に例えば熱硬化性樹脂を含むことでその砥石部１６に必要十分な耐熱性を付与できる。すなわち、比較的薄手の肉厚を備えた砥石部１６を容易に成形できる、研磨性能及び耐用寿命に優れた超砥粒ホイール１０の製造方法を提供することができる。
【００３９】
また、前記流動性樹脂は、光硬化性樹脂と熱硬化性樹脂とを含むものであるため、前記第１硬化工程Ｐ３にて前記光硬化性樹脂を硬化させた半硬化原料を、続く第１切断工程Ｐ４及び巻取工程Ｐ５において所定の形状に加工した後、前記第２硬化工程Ｐ６にて前記熱硬化性樹脂を硬化させることで、比較的薄手の砥石部１６であっても成形が容易であることに加え、その砥石部１６に必要十分な耐熱性を付与できるという利点がある。
【００４０】
また、前記流動性樹脂は、硬化温度の異なる少なくとも２種類の熱硬化性樹脂を含むものであるため、前記第１硬化工程Ｐ３にて比較的硬化温度の低い熱硬化性樹脂を硬化させた半硬化原料を、続く第１切断工程Ｐ４及び巻取工程Ｐ５において所定の形状に加工した後、前記第２硬化工程Ｐ６にて比較的硬化温度の高い熱硬化性樹脂を硬化させることで、比較的薄手の砥石部１６であっても成形が容易であることに加え、その砥石部１６に必要十分な耐熱性を付与できるという利点がある。
【００４１】
また、前記流動性樹脂は、ラジカル重合性樹脂及び／又はカチオン重合性樹脂を含むものであるため、前記流動性樹脂として、例えばアクリル酸エステル等のラジカル重合性樹脂と、エポキシ樹脂等のカチオン重合性樹脂とを用いることで、前記第１硬化工程Ｐ３にて光ラジカル重合反応によりアクリル樹脂を硬化させた半硬化原料を、続く第１切断工程Ｐ４及び巻取工程Ｐ５において所定の形状に加工した後、前記第２硬化工程Ｐ６にて熱カチオン重合反応によりエポキシ樹脂部分を硬化させることで、比較的薄手の砥石部１６であっても成形が容易であることに加え、その砥石部１６に必要十分な耐熱性を付与できるという利点がある。
【００４２】
また、前記流動性樹脂に含まれるラジカル重合性樹脂の割合は、５０重量％以上９５重量％以下の範囲内であるため、前記第１硬化工程Ｐ３において光ラジカル重合反応によりアクリル樹脂が硬化することで好適に形状変形可能な必要十分な硬さを有する半硬化原料が得られるという利点がある。
【００４３】
また、前記超砥粒ホイール１０は、椀状を成す台金１２の端縁部１４にそれぞれ管状を成す前記複数の砥石部１６が固着されて成るものであるため、管状を成す砥石部１６の環状端部２０がワークの被加工面に好適に食い込むことで、前記超砥粒の平均粒径が比較的微細であっても優れた切れ味を示す超砥粒ホイール１０を製造できるという利点がある。
【００４４】
また、前記管状を成す砥石部１６は、２ｍｍφ以上２０ｍｍφ以下の外径寸法Ｒと、２ｍｍ以上２０ｍｍ以下の高さ寸法ｈと、０．０５ｍｍｔ以上３ｍｍｔ以下の径方向厚さ寸法ｔとを備えたものであり、０．５ｍｍ以上５０ｍｍ以下の相互間隔で前記台金１２に固着されたものであるため、前記砥石部１６の環状端部２０がワークの被加工面に更に好適に食い込むという利点がある。
【００４５】
また、前記混合工程Ｐ１は、その平均粒径が前記超砥粒の平均粒径の８０％以下である球状の充填材を、その超砥粒と充填材とを合わせて前記流動性樹脂の３体積％以上１００体積％以下の範囲内となるように混合するものであるため、前記砥石部１６の砥石組織内に、前記超砥粒を更に好適に分散させられるという利点がある。
【００４６】
また、前記超砥粒の平均粒径は、０．５μｍ以上１０μｍ以下の範囲内であり、前記充填材の平均粒径は、０．１μｍ以上１μｍ以下の範囲内であるため、硬質脆性材料を更に好適に研磨加工し得る前記超砥粒ホイール１０を製造できるという利点がある。
【００４７】
また、前記管状を成す砥石部２２は、前記超砥粒の平均粒径、結合度、及び／又は集中度の異なる少なくとも２種類の超砥粒層がその径方向に積層されて形成されたものであるため、例えば摩耗し難いが研磨性能に劣る第１超砥粒層２４と、摩耗し易いが研磨性能に優れた第２超砥粒層２６とを交互に積層することで、前記砥石部２２延いては前記超砥粒ホイール１０の研磨性能及び耐用寿命を更に向上させることができるという利点がある。
【００４８】
また、前記超砥粒ホイール３０は、椀状を成す台金３２の端縁部にそれぞれ部分円筒状を成す前記複数の砥石部３４が固着されて成るものであるため、部分円筒状を成す砥石部３４の弧状端部がワークの被加工面に好適に食い込むことで、前記超砥粒の平均粒径が比較的微細であっても優れた切れ味を示す超砥粒ホイール３０を製造できるという利点がある。
【００４９】
以上、本発明の好適な実施例を図面に基づいて詳細に説明したが、本発明はこれに限定されるものではなく、更に別の態様においても実施される。
【００５０】
例えば、図６は、本発明の一実施例であるレジノイド超砥粒ホイールの製造方法が適用された更に別の一例である超砥粒ホイール４０を示す斜視図である。本発明は、図１又は図５に示すような椀状の台金１２又は３２の端縁部に前記複数の砥石部１６又は３４が固着されて成る平面研磨用カップ型ホイールに限られず、例えばこの図６に示すように、円板状の台金４２の平面部４４にそれぞれ管状を成す複数（図６では７２個）の砥石部１６が固着されて成る平面研磨用ディスク型ホイールに適用されてもよい。すなわち、本発明は、比較的薄手の肉厚を備えた複数の砥石部が固着されて成る様々な態様の超砥粒ホイールに広く用いられるものである。
【００５１】
また、前述の実施例では、前記混合工程Ｐ１において、前記超砥粒、合成樹脂結合剤、及び球状の充填材が混合されていたが、この球状の充填材に替えて或いはその球状の充填材と共に、例えばセラミックス、金属、又は金属化合物等から成る強化繊維を混合しても構わない。また、必要に応じて様々な添加剤が混合され得ることは言うまでもない。
【００５２】
また、前述の実施例では、前記混合工程Ｐ１により混合された流動性原料に含まれる前記流動性樹脂の一部を硬化させる第１硬化工程Ｐ３及びその第１硬化工程Ｐ３により一部が硬化した半硬化原料に含まれる前記流動性樹脂の残部を硬化させる第２硬化工程Ｐ６の二段階の硬化工程を含むものであったが、例えば三段階乃至それ以上の硬化工程を含むものであったも構わない。この場合、それぞれの硬化工程における硬化条件にて硬化する所定の流動性樹脂が前記混合工程Ｐ１において適宜混合される。
【００５３】
その他、一々例示はしないが、本発明はその趣旨を逸脱しない範囲内において、種々の変更が加えられて実施されるものである。
【図面の簡単な説明】
【図１】本発明の一実施例であるレジノイド超砥粒ホイールの製造方法が適用されたレジノイド超砥粒ホイールを示す斜視図である。
【図２】図１のレジノイド超砥粒ホイールに設けられる砥石部を拡大して示す斜視図である。
【図３】本発明の一実施例であるレジノイド超砥粒ホイールの製造方法を説明する工程図である。
【図４】図１のレジノイド超砥粒ホイールに設けられる砥石部の他の一例を拡大して示す斜視図である。
【図５】本発明の一実施例であるレジノイド超砥粒ホイールの製造方法が適用されたレジノイド超砥粒ホイールの他の一例を示す斜視図である。
【図６】本発明の一実施例であるレジノイド超砥粒ホイールの製造方法が適用されたレジノイド超砥粒ホイールの更に別の一例を示す斜視図である。
【符号の説明】
１０、３０、４０：レジノイド超砥粒ホイール
１２、３２、４２：台金
１４：端縁部
１６、２２、３４：砥石部
Ｐ１：混合工程
Ｐ３：第１硬化工程
Ｐ６：第２硬化工程[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an improvement in a method of manufacturing a resinoid superabrasive wheel in which a plurality of grindstone portions formed by bonding a number of superabrasive particles to each other with a synthetic resin binder are fixed to a base metal.
[0002]
[Prior art]
A super-abrasive grain wheel in which a plurality of super-abrasive grains formed by bonding a plurality of super-abrasive grains to each other with a predetermined binder is fixed to a base metal is frequently used in grinding in various fields. As one mode of such a superabrasive wheel, a so-called cup type superabrasive wheel is known in which the plurality of grindstone portions are fixed to an edge of a base metal having a bowl shape (cup shape) (for example, See Patent Document 1). This cup-type superabrasive wheel is suitably used for polishing hard brittle materials such as silicon, compound semiconductor, glass, ceramics, ferrite, quartz, quartz, and cemented carbide. Conventionally, polishing of such a hard brittle material has been mainly performed by polishing, in which a workpiece and a polishing platen are slid in contact with each other and a slurry (slurry) containing abrasive particles is supplied therebetween. The cup-type superabrasive wheel described above is expected as an alternative technology because the abrasive particles that are not involved are uneconomical and generate a large amount of waste.
[0003]
[Patent Document 1]
JP-A-2001-219377
[0004]
By the way, as a binder for binding the plurality of abrasive grains to each other, a synthetic resin binder (resin bond), a vitreous binder (vitrified bond), a metallic binder (metal bond), and an electrodeposition (electroforming) And the like. However, when polishing the hard brittle material, a relatively high rigidity of vitreous binder, metallic binder, and electrodeposition are likely to cause defects such as scratches. A synthetic resin binder having relatively low rigidity is used.
[0005]
[Problems to be solved by the invention]
However, in a resinoid superabrasive wheel using a generally well-known powder resin such as powder phenol as a binder, the average diameter of the powder resin is relatively large at about 30 μm. When such relatively fine superabrasive grains are used, such a large number of superabrasive grains are not suitably dispersed, and there is a problem that desired polishing performance cannot be obtained. Therefore, it is conceivable to use a fluid resin such as liquid phenol as a binder. However, since such a fluid resin contains a large amount of volatile components, it tends to be warped or deformed during molding and is not suitable for practical use. Therefore, a synthetic resin binder in which a powder resin and a fluid resin are mixed is often used. However, the dispersibility and moldability of the superabrasive grains are slightly sacrificed, and further, the synthetic resin binder having poor heat resistance is used. The agent has a disadvantage that the service life is shortened due to heat generated during polishing. In particular, when the grindstone portion has a relatively thin wall thickness (thickness dimension) such as a tubular (pipe-shaped) or partially cylindrical shape, it is difficult to form the grindstone portion, and there is a limit in improving the polishing performance and the service life. .
[0006]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a resinoid excellent in polishing performance and service life, which can easily form a grindstone portion having a relatively thin wall thickness. An object of the present invention is to provide a method for manufacturing a superabrasive wheel.
[0007]
[Means for Solving the Problems]
In order to achieve such an object, the gist of the present invention is to provide a resinoid superconducting element comprising a plurality of grinding stones formed by bonding a number of superabrasive grains to each other with a synthetic resin binder, and being fixed to a base metal. A method for manufacturing an abrasive wheel, wherein a mixing step of mixing the large number of superabrasive grains and at least two types of flowable resins having different curing conditions as raw materials of the synthetic resin binder, and being mixed by the mixing step A first curing step of curing a part of the fluid resin contained in the fluid material, and a second curing step of curing the remaining part of the fluid resin contained in the semi-cured material partially cured by the first curing step. And two curing steps.
[0008]
【The invention's effect】
By doing so, a mixing step of mixing the large number of superabrasive grains and at least two types of flowable resins having different curing conditions as raw materials of the synthetic resin binder, and a flowable raw material mixed by the mixing step A first curing step of curing a part of the fluid resin contained in the first curing step, and a second curing step of curing the remaining part of the fluid resin contained in the semi-cured material partially cured by the first curing step; Since the semi-cured raw material that has passed through the first curing step is processed into a predetermined shape in the subsequent step, and then fully cured in the second curing step, even a relatively thin grindstone portion In addition to being easy to form, the superabrasive grains can be suitably dispersed in the grindstone structure of the grindstone portion, and furthermore, for example, by including a thermosetting resin, the necessary and sufficient heat resistance of the grindstone portion can be obtained. Can be given. That is, it is possible to provide a method for manufacturing a resinoid superabrasive wheel excellent in polishing performance and service life, which can easily form a grindstone portion having a relatively thin wall thickness.
[0009]
Other aspects of the invention
Here, preferably, the fluid resin includes a photocurable resin and a thermosetting resin. In this case, the semi-cured material obtained by curing the photocurable resin in the first curing step is processed into a predetermined shape in a subsequent step, and then the thermosetting resin is cured in the second curing step. By curing, there is an advantage that not only a relatively thin grindstone portion can be easily formed, but also the necessary and sufficient heat resistance can be imparted to the grindstone portion.
[0010]
Preferably, the fluid resin includes at least two types of thermosetting resins having different curing temperatures. With this configuration, the semi-cured raw material obtained by curing the thermosetting resin having a relatively low curing temperature in the first curing step is processed into a predetermined shape in a subsequent step, and then processed in the second curing step. By curing a thermosetting resin having a relatively high curing temperature, it is easy to mold even a relatively thin grindstone part, and the advantage that it can impart necessary and sufficient heat resistance to the grindstone part is obtained. is there.
[0011]
Preferably, the fluid resin contains a radical polymerizable resin and / or a cationic polymerizable resin, and more preferably contains an acrylic resin and / or an epoxy resin. According to this configuration, as the fluid resin, for example, by using a radical polymerizable resin such as an acrylate ester and a cationic polymerizable resin such as an epoxy resin, the photo-radical polymerization reaction in the first curing step. The semi-cured raw material obtained by curing the acrylic resin is processed into a predetermined shape in a subsequent step, and then the epoxy resin portion is cured by a thermal cation polymerization reaction in the second curing step. Even if it does, there is an advantage that in addition to being easy to form, the necessary and sufficient heat resistance can be imparted to the grindstone portion.
[0012]
Preferably, the ratio of the radical polymerizable resin contained in the fluid resin is in a range of 50% by weight or more and 95% by weight or less. This has the advantage that the acrylic resin is cured by the photo-radical polymerization reaction in the first curing step, so that a semi-cured raw material having a necessary and sufficient hardness capable of being suitably deformed can be obtained. When the ratio of the radical polymerizable resin contained in the fluid resin is less than 50% by weight, the hardness of the semi-cured raw material is insufficient. Becomes too hard, and in either case, shape deformation becomes difficult.
[0013]
Preferably, the resinoid superabrasive grain wheel is formed by fixing the plurality of tubular grindstone portions to an edge of a bowl-shaped base metal. With this configuration, the annular end portion of the grindstone portion having a tubular shape preferably bites into the work surface of the workpiece, so that the resinoid exhibits excellent sharpness even when the average particle size of the superabrasive grains is relatively fine. There is an advantage that a superabrasive wheel can be manufactured.
[0014]
Further, preferably, the grinding wheel portion forming the tubular shape has an outer diameter of 2 mmφ or more and 20 mmφ or less, a height of 2 mm or more and 20 mm or less, and a radial thickness of 0.05 mmt or more and 3 mmt or less. More preferably, they are fixed to the base metal at an interval of 0.5 mm or more and 50 mm or less. In this case, there is an advantage that the annular end portion of the grinding wheel portion more suitably cuts into the work surface of the work.
[0015]
Also, preferably, the grindstone portion forming the tube is formed by laminating at least two types of superabrasive layers having different average particle diameters, bonding degrees, and / or degrees of concentration of the superabrasive particles in the radial direction. It was done. By doing so, for example, the first superabrasive layer, which is hard to wear but has poor polishing performance, and the second superabrasive layer, which is easy to wear but excellent in polishing performance, are alternately laminated, whereby the grinding wheel portion is formed. In addition, there is an advantage that the polishing performance and service life of the resinoid superabrasive wheel can be further improved.
[0016]
Preferably, the resinoid superabrasive grain wheel is formed by fixing the plurality of grinding stone portions each partially forming a cylindrical shape to an edge portion of a base metal forming a bowl shape. With this configuration, the arc-shaped end portion of the grinding wheel portion having a partially cylindrical shape preferably bites into the work surface of the work, so that the super-abrasive grains have excellent sharpness even if the average particle size is relatively fine. There is an advantage that the resinoid superabrasive wheel shown can be manufactured.
[0017]
Preferably, in the mixing step, the spherical filler having an average particle size of 80% or less of the average particle size of the superabrasive particles is combined with the superabrasive particles and the filler to obtain the fluidity. The resin is mixed so as to be in a range of 3% by volume or more and 100% by volume or less of the resin. This has the advantage that the superabrasive grains can be more suitably dispersed in the grindstone structure of the grindstone portion.
[0018]
Preferably, the average particle size of the superabrasive particles is in a range from 0.5 μm to 10 μm, and the average particle size of the filler is in a range from 0.1 μm to 1 μm. By doing so, there is an advantage that a resinoid superabrasive wheel capable of more suitably polishing hard brittle materials can be manufactured.
[0019]
【Example】
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.
[0020]
FIG. 1 is a perspective view showing a resinoid superabrasive wheel (hereinafter, simply referred to as a superabrasive wheel) 10 to which a method for manufacturing a resinoid superabrasive wheel according to an embodiment of the present invention is applied. As shown in FIG. 1, the superabrasive wheel 10 is made of a metal material such as steel or aluminum alloy, or a synthetic resin material such as engineering plastic, and has a base having a bowl shape (cup shape) having an outer diameter of about 250 mmφ. It is composed of a gold 12 and a plurality of (34 in FIG. 1) grindstone portions 16 each of which has a tubular (pipe) shape and is fixed to an edge portion (annular surface) 14 of the base metal 12. At the center of the bottom of the base metal 12, a mounting hole 18 for being mounted on a rotating main shaft of a predetermined polishing device (not shown) at the time of polishing is penetrated.
[0021]
The above-mentioned grindstone portion 16 is composed of, for example, a large number of superabrasive grains made of diamond or CBN and having an average particle diameter in a range of 0.5 μm or more and 10 μm or less, mutually bonded by a predetermined synthetic resin binder described later. It was formed. Preferably, a spherical filler (filler) made of silica or alumina having an average particle size of 80% or less of the average particle size of the superabrasive particles, that is, 0.1 μm or more and 1 μm or less is used. It contains. FIG. 2 is an enlarged perspective view of the whetstone unit 16. As shown in FIG. 2, the grinding stone portion 16 preferably has an outer diameter R of 2 mmφ or more and 20 mmφ or less, a height h of 2 mm or more and 20 mm or less, and a radial thickness of 0.05 mmt or more and 3 mmt or less. And more preferably, it is fixed to the base metal 12 at an interval of 0.5 mm or more and 50 mm or less by, for example, an epoxy resin adhesive or the like.
[0022]
The super-abrasive grain wheel 10 configured as described above is mounted so as to be coaxial with a rotation main shaft of a predetermined polishing device in the mounting hole 18, and is driven to rotate around its axis S, This is a so-called planar polishing cup-type wheel in which a polishing surface is formed by the annular end portion 20 of the grindstone portion 16 and a work (not shown) is polished by the polishing surface. The superabrasive wheel 10 is preferably used for polishing hard brittle materials such as silicon, compound semiconductors, glass, ceramics, ferrite, quartz, quartz, and cemented carbide.
[0023]
FIG. 3 is a process chart illustrating a method for manufacturing a resinoid superabrasive wheel according to one embodiment of the present invention. As shown in FIG. 3, first, in the mixing step P1, the large number of superabrasive grains and the fluid resin that is the raw material of the synthetic resin binder are mixed and stirred to be a fluid (paste) raw material. You. The fluid resin as a raw material of the synthetic resin binder is composed of at least two kinds of fluid resins having different curing conditions (crosslinking conditions), and includes, for example, a photocurable resin and a thermosetting resin, Alternatively, it contains at least two types of thermosetting resins having different curing temperatures. In the mixing step P1, a predetermined cationic polymerization catalyst or the like is added as necessary.
[0024]
Here, preferably, the fluid resin contains a radical polymerizable resin and / or a cationic polymerizable resin, and more preferably contains an acrylic resin and / or an epoxy resin. Specifically, it contains at least two kinds of cationically polymerizable resins having different curing temperatures, for example, a cycloaliphatic epoxy resin and a glycidyl ether resin. These are all thermosetting resins, but have different curing temperatures due to their superiority in cationic polymerization. That is, the curing temperature of the cycloaliphatic epoxy resin having relatively excellent cationic polymerization is about 120 ° C., and the curing temperature of glycidyl ether resin having relatively poor cationic polymerization is about 180 ° C.
[0025]
Preferably, in the mixing step P1, the ratio of the superabrasive grains to the flowable resin is 3% by volume or more and 100% by volume or less, and the ratio of the flowable resin to the entire flowable raw material is 50% by volume or more and 95% by volume. %, The volume ratio of the input raw material is determined in advance. Further, if necessary, 1% by volume or more and 97% by volume or less of the filler based on the fluid resin is appropriately added. That is, preferably, the sum of the superabrasive grains and the filler is in the range of 3% by volume to 100% by volume of the fluid resin.
[0026]
The fluid raw material mixed and stirred in the mixing step P1 is formed into a thin plate shape by rolling in a subsequent rolling step P2. Specifically, about 10 g of the fluid raw material is sandwiched between a pair of PET sheets having a thickness of about 50 μmt, which have been subjected to a surface treatment with a release agent, and are rolled, so that a surface area of 250 mm ² × The sheet is stretched to a thickness of about 200 μmt.
[0027]
In the following first hardening step P3, the flowable raw material stretched into a thin plate shape in the rolling step P2 has a predetermined first temperature T ₁ , And a part of the fluid resin is cured to be a semi-cured raw material. Specifically, the first temperature T of about 120 ° C. ₁ Is subjected to a heat treatment of holding for 1 hour, whereby the cycloaliphatic epoxy resin contained in the fluid raw material is cured, and has a predetermined formability, but is easily deformed such as cutting or bending. It is a thin plate-shaped semi-cured raw material having a thickness of about 200 μmt. Here, since the glycidyl ether resin contained in the fluid raw material is relatively inferior in cationic polymerizability, the first temperature T ₁ It is not cured by heat treatment at a relatively low temperature for a short time such as holding for 1 hour.
[0028]
The semi-cured raw material in which a part of the fluid resin is cured in the first curing step P3 is separated from the PET sheet, and then, in a subsequent first cutting step P4, for example, a rectangular shape of about 20 mm × 75 mm. Cut into shapes. In the subsequent winding step P5, the resin is wound around a cylindrical resin material of, for example, about 4 mmφ × 20 mm with a displacement of about 10 mm.
[0029]
In the subsequent second curing step P6, the semi-cured raw material wound around the cylindrical resin material in the above-mentioned winding step P5 has a predetermined second temperature T. ₂ Heat treatment is performed to harden the remainder of the fluid resin, that is, substantially all of the fluid resin contained in the semi-cured raw material. Specifically, the second temperature T of about 180 ° C. ₂ After the glycidyl ether resin contained in the flowable raw material is cured by performing a heat treatment of holding for 3 hours in the above, in a subsequent second cutting step P7, the glycidyl ether resin is pulled out of the columnar resin and has a predetermined length. By being cut to the same size, it is formed as a grindstone portion 16 as shown in FIG.
[0030]
After the plurality of grindstone portions 16 formed as described above are fixed to the edge portion 14 of the base metal 12 with, for example, an epoxy resin adhesive in a fixing step P8, a predetermined number of The superabrasive wheel 10 as shown in FIG. 1 is manufactured by shaping the shape by cutting or the like.
[0031]
The flowable resin mixed in the above-described mixing step P1 includes a photocurable resin and a thermosetting resin, such as a photopolymerizable radical polymerizable resin and a thermosetting cationic polymerizable resin. It may be something. Specifically, a radical polymerizable resin such as an acrylate ester and a cationic polymerizable resin such as an epoxy resin are preferably used. In this case, the acrylic resin is cured by the photoradical polymerization reaction in the first curing step P3, and the epoxy resin part is cured by the thermal cation polymerization reaction in the second curing step P6. Preferably, the ratio of the radical polymerizable resin contained in the fluid resin is in the range of 50% by weight or more and 95% by weight or less. When this ratio is less than 50% by weight, the hardness of the semi-cured raw material obtained by curing the acrylic resin by the photoradical polymerization reaction in the first curing step P3 described later becomes insufficient, while the hardness is less than 95% by weight. When it is large, the semi-cured raw material becomes too hard, and in any case, the shape deformation becomes difficult.
[0032]
Further, in the mixing step P1 to the first curing step P3, at least two types of semi-cured raw materials having different average particle diameters, bonding degrees, and / or concentration degrees of the superabrasive grains are formed, and in the winding step P5, By alternately winding the plurality of types of semi-cured raw materials, for example, as shown in FIG. 4, at least two types of superabrasives having different average particle diameters, bonding degrees, and / or concentration degrees of the superabrasive grains. The grindstone layer 22 may be formed by laminating the grain layers in the radial direction. The first superabrasive layer 24 having a relatively small average particle diameter, a relatively high degree of bonding, and / or a relatively low degree of concentration of the superabrasive grains is hard to wear but has poor polishing performance. The second superabrasive layer 26 having a relatively large average particle diameter, a relatively low bonding degree, and / or a relatively high degree of concentration tends to be worn, but has excellent polishing performance. As described above, in the grindstone portion 22 in which at least two types of superabrasive layers having different average particle diameters, bonding degrees, and / or degrees of concentration of the superabrasive grains are laminated in the radial direction thereof, The provision of the superabrasive layer 24 makes it less likely to wear during polishing, and the provision of the second superabrasive layer 26 ensures excellent sharpness.
[0033]
FIG. 5 is a perspective view showing a superabrasive wheel 30 as another example to which the method for manufacturing a resinoid superabrasive wheel according to the present invention is applied. As shown in FIG. 3, in the superabrasive grain wheel 30 of the present embodiment, a plurality of (12 in FIG. 5) grinding stone portions 34 each of which has a partially cylindrical shape are provided at an edge portion of a base metal 32 having a bowl shape. It may be a so-called planar polishing cup-type wheel fixed in a state of being arranged in a cylindrical shape (ring shape). The grindstone portion 34, like the grindstone portion 16 provided in the superabrasive wheel 10, includes a large number of superabrasive grains and at least two types of fluid resins having different curing conditions as raw materials of the synthetic resin binder. Are mixed, and the first temperature T ₁ The semi-cured raw material in which a part of the fluid resin is cured is cut and deformed at the second temperature T. ₂ The remaining portion of the fluid resin contained in the semi-cured material is cured at a temperature of, for example, 0.05 mmt or more and 3 mmt or less in a radial thickness, and is protruded from the base 32 by about 10 mm. It is provided. The above-described hard and brittle material can also be suitably polished by the superabrasive wheel 30 provided with such a grindstone portion 34.
[0034]
[Example of experiment]
Hereinafter, a polishing test performed by the present inventors to verify the effect of the present invention will be described. The present inventors first considered that 31.25% by volume of diamond abrasive grains having an average particle size of 5 μm, 3.75% by volume of spherical alumina having an average particle size of 0.6 μm, and 2.5% by volume of carbon black. Example sample 1 in which a tubular grindstone portion 16 having a dimension of about 6 mm in outer diameter, 4 mm in inner diameter, and about 5 mm in height, formed using 62.5% by volume of a synthetic resin binder as a raw material, is fixed. 31.25% by volume of diamond abrasive grains having an average particle diameter of 3 μm; 3.75% by volume of spherical alumina having an average particle diameter of 0.6 μm; 2.5% by volume of carbon black; Example Sample 2 formed by fixing a tubular grindstone portion 16 having the same size as the above-mentioned Example Sample 1 formed from 5% by volume as a raw material, and formed from the same raw material as the above-mentioned Example Sample 1. With a thickness of about 3 mmt Example sample 3 in which stone portion 34 is fixed in a state protruding from base metal 32 by about 5 mm, and thickness example similar to that of example sample 3 formed from the same raw material as example sample 2 described above. An example sample 4 was manufactured in which the provided grindstone portion 34 was fixed in a state protruding from the base metal 32 to the same extent as the example sample 3. Here, Ketjen Black manufactured by Ketjen Black International Co., Ltd. was used as the carbon black, and 40 parts by volume of Celloxide 2021P manufactured by Daicel Chemical Industries, Ltd. was used as the synthetic resin binder. Of EHPE-3150CE, 10 parts by volume of Denacol EX-252 manufactured by Nagase ChemteX Corporation, and 3 parts by volume of San Aid SI-110L of Sanshin Chemical Industry Co., Ltd., which is a cationic polymerization initiator. Were used in a mixture.
[0035]
Example samples 1 to 4 configured as described above and diamond samples having an average particle diameter of about 5 μm have dimensions similar to those of the above-mentioned example samples 1 and 2 formed by bonding with a vitreous binder. A comparative example sample 1 in which a tubular grindstone portion is fixed, and the same size as the above example samples 1 and 2 formed by bonding diamond abrasive grains having an average particle diameter of about 3 μm with a vitreous binder. A polishing test was performed using Comparative Example Sample 2 in which the provided tubular grindstone portion was fixed. The test conditions and test results are shown below.
[0036]
[Test condition]
Whetstone outer diameter: 250mmφ
Polishing equipment: Surface grinder
Wheel speed: 2000m / min
Cutting speed: 20 μm / min
Cutting depth: Total 40μm
Work material: Single crystal silicon wafer
Polishing liquid: pure water

[0037]
As is apparent from the test results, the samples of Examples 1 to 4, which are one example of the present invention, have relatively fine diamond abrasive grains having a relatively large diameter of about 5 μm, ie, about 3 μm. Regardless of degree, both sharpness and work surface quality are excellent. On the other hand, it was confirmed that the samples of Comparative Examples 1 and 2 manufactured by the prior art did not have sufficient workpiece surface quality and could not perform normal polishing. That is, according to the superabrasive wheel applied to the present invention, it was verified that polishing of a hard brittle material such as a single crystal silicon wafer, which was impossible with a conventional superabrasive wheel, can be suitably performed. .
[0038]
As described above, according to the present embodiment, the mixing step P1 of mixing the large number of superabrasive grains and at least two types of fluid resins having different curing conditions as raw materials of the synthetic resin binder, and the mixing step P1 A first curing step P3 for curing a part of the fluid resin contained in the fluid material mixed by the method, and the fluid resin contained in the semi-cured material partially cured by the first curing step P3. Since the semi-cured material that has passed through the first curing step P3 is processed into a predetermined shape in a subsequent first cutting step P4 and a winding step P5, the second curing step P6 for curing the remaining portion is included. 2 By hardening in the hardening step P6, it is possible to easily form even the relatively thin grindstone portion 16 and to appropriately disperse the superabrasive grains in the grindstone structure of the grindstone portion 16. Can be updated For example, grant the necessary and sufficient heat resistance to the grindstone 16 by containing a thermosetting resin. In other words, it is possible to provide a method of manufacturing the superabrasive wheel 10 which is capable of easily forming the grindstone portion 16 having a relatively thin wall thickness and which is excellent in polishing performance and service life.
[0039]
Further, since the flowable resin contains a photocurable resin and a thermosetting resin, the semi-cured raw material obtained by curing the photocurable resin in the first curing step P3 is subjected to a first cutting step. After processing into a predetermined shape in P4 and the winding step P5, the thermosetting resin is cured in the second curing step P6, so that the relatively thin grindstone portion 16 can be easily formed. In addition, there is an advantage that the necessary and sufficient heat resistance can be imparted to the grindstone portion 16.
[0040]
Further, since the fluid resin contains at least two kinds of thermosetting resins having different curing temperatures, the semi-cured raw material obtained by curing the thermosetting resin having a relatively low curing temperature in the first curing step P3. Is processed into a predetermined shape in a subsequent first cutting step P4 and a winding step P5, and then, in the second curing step P6, a thermosetting resin having a relatively high curing temperature is cured, so that a relatively thin layer is formed. Even in the case of the grindstone portion 16, there is an advantage that the molding is easy and the necessary and sufficient heat resistance can be imparted to the grindstone portion 16.
[0041]
In addition, since the fluid resin contains a radical polymerizable resin and / or a cationic polymerizable resin, as the fluid resin, for example, a radical polymerizable resin such as an acrylate ester and a cationic polymerizable resin such as an epoxy resin By using the above, the semi-cured raw material obtained by curing the acrylic resin by the photo-radical polymerization reaction in the first curing step P3 is processed into a predetermined shape in the subsequent first cutting step P4 and winding step P5. By hardening the epoxy resin portion by the thermal cationic polymerization reaction in the second hardening step P6, it is possible to easily form even the relatively thin grindstone portion 16 and to provide a necessary and sufficient There is an advantage that heat resistance can be imparted.
[0042]
Further, since the ratio of the radical polymerizable resin contained in the fluid resin is in the range of 50% by weight or more and 95% by weight or less, the acrylic resin is cured by the photoradical polymerization reaction in the first curing step P3. Thus, there is an advantage that a semi-cured raw material having a necessary and sufficient hardness capable of suitably deforming the shape can be obtained.
[0043]
Further, since the superabrasive wheel 10 is configured such that the plurality of tubular grindstone portions 16 are fixed to the edge portion 14 of the bowl-shaped base metal 12, the tubular grindstone portion 16 is Since the annular end portion 20 bites into the work surface of the work, there is an advantage that the superabrasive wheel 10 having excellent sharpness can be manufactured even if the average particle size of the superabrasive particles is relatively fine. .
[0044]
Further, the grindstone portion 16 forming the tubular shape has an outer diameter R of 2 mmφ or more and 20 mmφ or less, a height h of 2 mm or more and 20 mm or less, and a radial thickness t of 0.05 mmt or more and 3 mmt or less. And is fixed to the base metal 12 at a mutual interval of 0.5 mm or more and 50 mm or less. Therefore, there is an advantage that the annular end portion 20 of the grinding stone portion 16 bites into the work surface of the work more preferably. is there.
[0045]
Further, in the mixing step P1, a spherical filler having an average particle size of 80% or less of the average particle size of the superabrasive particles is combined with the superabrasive particles and the filler to form a 3D fluid resin. Since the mixing is performed so as to be within the range of not less than 100% by volume and not more than 100% by volume, there is an advantage that the superabrasive grains can be more suitably dispersed in the grindstone structure of the grindstone portion 16.
[0046]
Further, the average particle size of the superabrasive particles is in the range of 0.5 μm or more and 10 μm or less, and the average particle size of the filler is in the range of 0.1 μm or more and 1 μm or less. Further, there is an advantage that the superabrasive wheel 10 that can be suitably polished can be manufactured.
[0047]
In addition, the grindstone portion 22 forming the tubular shape is formed by laminating at least two types of superabrasive layers having different average particle diameters, bonding degrees, and / or concentrations of the superabrasive particles in the radial direction. Therefore, for example, by alternately laminating the first superabrasive layer 24 that is hard to wear but has poor polishing performance and the second superabrasive layer 26 that is easy to wear but excellent in polishing performance, 22 has the advantage that the polishing performance and the service life of the superabrasive wheel 10 can be further improved.
[0048]
Further, since the superabrasive grain wheel 30 is formed by fixing the plurality of grindstone portions 34 each having a partially cylindrical shape to an edge portion of a base metal 32 having a bowl shape, a whetstone having a partially cylindrical shape is formed. Advantageously, since the arc-shaped end of the portion 34 bites into the work surface of the work, the superabrasive wheel 30 having excellent sharpness can be manufactured even if the average particle size of the superabrasive is relatively fine. There is.
[0049]
As described above, the preferred embodiments of the present invention have been described in detail with reference to the drawings. However, the present invention is not limited to these embodiments, and may be implemented in other embodiments.
[0050]
For example, FIG. 6 is a perspective view showing a superabrasive grain wheel 40 as still another example to which the method of manufacturing a resinoid superabrasive grain wheel according to an embodiment of the present invention is applied. The present invention is not limited to the flat grinding cup type wheel in which the plurality of grinding

stones

16 or 34 are fixed to the edge of the bowl-shaped

base metal

12 or 32 as shown in FIG. 1 or FIG. As shown in FIG. 6, the present invention is applied to a disk type wheel for planar polishing in which a plurality of tubular grinding wheels 16 (72 in FIG. 6) are fixed to a flat surface 44 of a disk-shaped base 42. You may. That is, the present invention is widely used for various types of superabrasive wheels in which a plurality of grindstone portions each having a relatively thin thickness are fixed.
[0051]
Further, in the above-described embodiment, in the mixing step P1, the superabrasive grains, the synthetic resin binder, and the spherical filler are mixed, but the spherical filler is replaced with the spherical filler or the spherical filler. At the same time, reinforcing fibers made of, for example, ceramics, metal, or a metal compound may be mixed. Needless to say, various additives can be mixed as needed.
[0052]
In the above-described embodiment, the first curing step P3 for curing a part of the flowable resin contained in the flowable raw material mixed in the mixing step P1 and the part was cured in the first curing step P3. Although the two-stage curing process of the second curing process P6 for curing the remaining portion of the fluid resin contained in the semi-cured raw material is included, for example, three or more stages of curing are included. I do not care. In this case, a predetermined fluid resin that is cured under the curing conditions in each curing step is appropriately mixed in the mixing step P1.
[0053]
Although not specifically exemplified, the present invention is embodied with various changes without departing from the spirit thereof.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a resinoid superabrasive grain wheel to which a method for manufacturing a resinoid superabrasive grain wheel according to an embodiment of the present invention is applied.
FIG. 2 is an enlarged perspective view showing a grindstone portion provided on the resinoid superabrasive grain wheel of FIG. 1;
FIG. 3 is a process diagram illustrating a method for manufacturing a resinoid superabrasive wheel according to one embodiment of the present invention.
FIG. 4 is an enlarged perspective view showing another example of a grindstone portion provided in the resinoid superabrasive grain wheel of FIG. 1;
FIG. 5 is a perspective view showing another example of a resinoid superabrasive grain wheel to which a method for manufacturing a resinoid superabrasive grain wheel according to an embodiment of the present invention is applied.
FIG. 6 is a perspective view showing still another example of a resinoid superabrasive grain wheel to which a method for manufacturing a resinoid superabrasive grain wheel according to an embodiment of the present invention is applied.
[Explanation of symbols]
10, 30, 40: Resinoid super abrasive wheel
12, 32, 42: Deposit
14: Edge
16, 22, 34: whetstone part
P1: mixing process
P3: First curing step
P6: Second curing step

Claims

A method for manufacturing a resinoid superabrasive grain wheel in which a plurality of superabrasive grains are bonded to each other by a synthetic resin binder and a plurality of grindstone portions are fixed to a base metal,
A mixing step of mixing at least two types of flowable resins having different curing conditions as raw materials of the large number of superabrasive grains and the synthetic resin binder,
A first curing step of curing a part of the flowable resin contained in the flowable raw material mixed in the mixing step,
A second curing step of curing the remaining portion of the fluid resin contained in the semi-cured material partially cured in the first curing step.

The method for manufacturing a resinoid superabrasive wheel according to claim 1, wherein the fluid resin includes a photocurable resin and a thermosetting resin.

The method for manufacturing a resinoid superabrasive wheel according to claim 1, wherein the fluid resin includes at least two types of thermosetting resins having different curing temperatures.

The method for manufacturing a resinoid superabrasive grain wheel according to any one of claims 1 to 3, wherein the fluid resin includes a radical polymerizable resin and / or a cationic polymerizable resin.

The method for producing a resinoid superabrasive wheel according to any one of claims 1 to 4, wherein the fluid resin includes an acrylic resin and / or an epoxy resin.

The method for producing a resinoid superabrasive wheel according to claim 4 or 5, wherein a ratio of the radical polymerizable resin contained in the fluid resin is in a range of 50% by weight or more and 95% by weight or less.

The resinoid superabrasive grain wheel according to any one of claims 1 to 6, wherein the resinoid superabrasive grain wheel is formed by fixing the plurality of tubular grindstone portions to an edge of a base metal having a bowl shape. Manufacturing method.