JPS6311291B2 - - Google Patents
Info
- Publication number
- JPS6311291B2 JPS6311291B2 JP9444483A JP9444483A JPS6311291B2 JP S6311291 B2 JPS6311291 B2 JP S6311291B2 JP 9444483 A JP9444483 A JP 9444483A JP 9444483 A JP9444483 A JP 9444483A JP S6311291 B2 JPS6311291 B2 JP S6311291B2
- Authority
- JP
- Japan
- Prior art keywords
- glass
- ferrite
- less
- thermal expansion
- magnetic head
- 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.)
- Expired
Links
- 239000011521 glass Substances 0.000 claims description 52
- 239000000203 mixture Substances 0.000 claims description 20
- 229910004298 SiO 2 Inorganic materials 0.000 claims description 4
- 229910018072 Al 2 O 3 Inorganic materials 0.000 claims description 3
- 239000012535 impurity Substances 0.000 claims 2
- KKCBUQHMOMHUOY-UHFFFAOYSA-N Na2O Inorganic materials [O-2].[Na+].[Na+] KKCBUQHMOMHUOY-UHFFFAOYSA-N 0.000 claims 1
- 229910000859 α-Fe Inorganic materials 0.000 description 19
- 230000003628 erosive effect Effects 0.000 description 7
- 239000000463 material Substances 0.000 description 5
- 238000003466 welding Methods 0.000 description 4
- 239000003513 alkali Substances 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000010828 elution Methods 0.000 description 3
- 239000000696 magnetic material Substances 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 230000006866 deterioration Effects 0.000 description 2
- 238000004031 devitrification Methods 0.000 description 2
- NUJOXMJBOLGQSY-UHFFFAOYSA-N manganese dioxide Chemical compound O=[Mn]=O NUJOXMJBOLGQSY-UHFFFAOYSA-N 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 230000001603 reducing effect Effects 0.000 description 2
- 125000006850 spacer group Chemical group 0.000 description 2
- 238000004017 vitrification Methods 0.000 description 2
- 229910001035 Soft ferrite Inorganic materials 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910052681 coesite Inorganic materials 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 229910052593 corundum Inorganic materials 0.000 description 1
- 229910052906 cristobalite Inorganic materials 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000012299 nitrogen atmosphere Substances 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000000750 progressive effect Effects 0.000 description 1
- 230000036647 reaction Effects 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 235000012239 silicon dioxide Nutrition 0.000 description 1
- 229910052682 stishovite Inorganic materials 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 229910052905 tridymite Inorganic materials 0.000 description 1
- 229910001845 yogo sapphire Inorganic materials 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
- C03C3/00—Glass compositions
- C03C3/04—Glass compositions containing silica
- C03C3/062—Glass compositions containing silica with less than 40% silica by weight
- C03C3/064—Glass compositions containing silica with less than 40% silica by weight containing boron
- C03C3/066—Glass compositions containing silica with less than 40% silica by weight containing boron containing zinc
Description
この発明は、ソフトフエライト、特にMn−Zn
フエライトで構成された磁気ヘツドのギヤツプ部
を形成するための非磁性材たるガラス組成物に係
り、フエライトへのガラス浸食並びにガラス内気
泡の発生を著しく減少させた磁気ヘツド用ガラス
組成物に関する。
一般に、磁気ヘツドは、フエライト等の磁性材
料からなるコアと、非磁性材料からなる構造部品
とをガラス溶着されて組立てる。すなわち、ギヤ
ツプ部はガラスをガラス流し込みあるいはガラス
グレージング法などによりコア間の所定空隙内に
溶融挾入して形成する。
いずれのガラス溶着方法であつても、当該ガラ
スをその軟化点以上の高い温度まで加熱するた
め、フエライトとガラスの界面におけるフエライ
トへのガラス浸食が発生し、光学的なギヤツプ長
と実効ギヤツプ長とに差が生じたり、またギヤツ
プ部を形成したガラス内に気泡が発生し、磁気ヘ
ツドに加工した際に記録媒体との摺動面に気泡や
露出して、これを起点とするフエライト結晶の脱
落や耐摩耗性の劣化が進行する問題があつた。
かかる問題を解決するのに、磁気ヘツドの製造
方法を改良して、ガラス浸食並びに気泡発生の防
止を図るのはもとより、使用するガラス自体の改
良により、本質的にガラス浸食、気泡発生の少な
いガラス組成物が切望されるところである。
この磁気ヘツド用ガラス組成物の好ましい性状
として、フエライトへの浸食が極力少なく、実
効ギヤツプ長が設定値に極力近似し得ること、
溶着時ガラス内の気泡発生が少なく強固に接着で
きること、アルカリ溶出量が少なく化学的に安
定していること、熱膨張係数がフエライトの熱
膨張係数と±15×10-7／℃の範囲内にあること、
磁気記録媒体に対して磁気ヘツドコアのフエラ
イトと同程度の耐摩耗性を有すること、が挙げら
れる。
この発明は、上述した性状を有する磁気ヘツド
用ガラス組成物を目的とし、また、近時、高透磁
率の故、デジタル用磁気ヘツド素材として多用さ
れるMn−Znフエライトで構成された磁気ヘツド
用ガラス組成物を目的としている。
すなわち、この発明は、
SiO2 15wt％〜22wt％、
B2O3 18wt％〜28wt％、
Al2O3 2wt％〜6wt％、
BaO 3wt％〜8wt％、
MnO2 0.2wt％〜4wt％、
及び、
NaO 4wt％〜10wt％、K2O 2wt％〜4wt％の
うち少なくとも１種を含有し残部が実質的にZnO
からなることを特徴とする磁気ヘツド用ガラス組
成物であり、あるいはさらに、
LiO2 2wt％以下、MgO 2wt％以下、
CaO 5wt％以下
のうち少なくとも１種を含有し、残部が実質的に
ZnOからなることを特徴とするガラス組成物であ
る。
以下に、この発明によるガラス組成物の組成範
囲を限定した理由を説明する。
SiO2は、22wt％を越えると熱膨張係数が小さ
くなりすぎ、ガラスの軟化点が高温度になつてフ
エライトへの浸食が発生しやすくなるため、ま
た、15wt％未満では化学的安定性に欠け耐久性
が低下するので好ましくないため、15wt％〜
22wt％とする。
B2O3は、ガラス粘性を調整及び失透傾向を抑
制するため含有するが、28wt％を越えると熱膨
張係数が小さくなりすぎ、また18wt％未満では
熱膨張係数が大きくなりすぎ、Mn−Znフエライ
トの熱膨張係数に対して±15×10-7／℃の範囲を
越えてしまうため、18wt％〜28wt％の含有とす
る。
Al2O3は、6wt％を越えると粘性が大となり、
ガラス溶着温度が高くなりすぎてフエライトへの
ガラス浸食が起りやすくなり、また2wt％未満で
はガラスの耐水性を劣化させるため、2wt％〜
6wt％の含有とする。
BaOは、失透傾向を減少する効果があるので、
3wt％〜8wt％の含有とする。
MnO2は、その含有が本発明によるガラス組成
物の特徴とするところで、ガラス化する際の電池
反応を抑制し、ガラス内に気泡生成するのを防止
するのに有効であるが、0.2wt％未満では気泡生
成防止の効果が少なく、また4wt％を越えると溶
融の際、還元性が大きくルツボ等を溶損するた
め、0.2wt％〜4wt％の含有とする。
Na2OとK2Oはガラス化促進のため含有するも
ので、Na2Oは、10wt％を越えるとフエライトと
反応しやすくなり好ましくなく、また4wt％未満
ではガラスに失透が起りやすく、ガラスの結晶化
にばらつきを生じ、ガラス強度を低下するため、
4wt％〜10wt％の含有とする。
K2Oは、4wt％を越えると熱膨張係数が大きす
ぎ、又2wt％未満では耐水性が劣化するため、
2wt％〜4wt％の含有とする。
ZnOは、本発明によるガラス組成物の主要成分
であり、ガラスのフエライトとの反応を抑制し、
ガラスの熱膨張係数をフエライトのそれに近似さ
せる効果がある。また、ZnOの最適量としては
26wt％〜30wt％である。
さらに、本発明によるガラス組成物において、
ガラスの耐水性改善のため、LiO、MgO、CaO
のうち少なくとも１種を含有するが、LiOは、
2wt％を越えると失透現象がおこり、熱膨張係数
等の特性にばらつきを生じるため好ましくなく、
また、2wt％を越えるMgO、5wt％を越えるCaO
は、ガラスの粘性を高め、失透傾向が速くなるの
で好ましくないため、それぞれLiO22wt％以下、
MgO2wt％以下、CaO5wt％以下とする。
以下に実施例を示す。
第１表に示す組成並びに熱膨張係数を有する
Mn−Znフエライト素材より、第１図に示す一対
の舟型コア１，２を作製し、各々の舟型コアの切
欠部を有する側のギヤツプ形成面に精密研摩を施
した。
１対の舟型コア１，２を各々スペーサー３，４
を介して研摩面を対向させて組み立て、コア１，
２のアペツクス部に近い位置に、第２表に示す組
成、軟化点、熱膨張係数を有するａ〜ｄの４種の
本発明によるガラス棒５をそれぞれ載置した。
次いで、使用したガラス棒５の軟化点以上であ
る730℃に加熱し、10分間保持してガラスを溶融
させ、毛細管現象によりギヤツプ部６内にガラス
を充填し、その後冷却固化させて第３図に示す磁
気ヘツド素材に仕上げた。なお、加熱は酸化によ
るMn−Znフエライトの変質防止のためN2雰囲気
で行なつた。
また、上述した条件並びにガラス流し込み方法
により、第２表に示す組成、軟化点、熱膨張係数
を有する本発明組成外の比較例（ｅ、ｆ）ガラス
棒を使用し、同様な磁気ヘツド素材を作製した。
次に、得られた磁気ヘツド素材における、ギヤ
ツプ部６のガラス内の気泡発生状況、アルカリ溶
出量、ビツカース硬度を調べた。結果は第３表に
示す。なお、気泡発生状況は、露出ガラス表面積
に対する気泡表面積の比を％で示した気泡発生率
（％）で評価した。
第２表並びに第３表の試験結果から明らかなよ
うに、この発明によるガラス組成物は、Mn−Zn
フエライトの熱膨張係数に近似した熱膨張係数を
有しており、ギヤツプ部内においても気泡発生が
皆無に近く、比較例ガラス組成物に対して著しく
少ないことがわかる。また、アルカリ溶出量も極
めて少なく化学的に安定しており、フエライトに
対する浸食もほとんどなく、実効ギヤツプ長が設
計値に近似していた。
This invention focuses on soft ferrite, especially Mn-Zn
The present invention relates to a glass composition that is a non-magnetic material for forming the gap portion of a magnetic head made of ferrite, and relates to a glass composition for a magnetic head that significantly reduces glass erosion of ferrite and the generation of bubbles within the glass. Generally, a magnetic head is assembled by glass welding a core made of a magnetic material such as ferrite and structural parts made of a non-magnetic material. That is, the gap portion is formed by melting and injecting glass into a predetermined gap between the cores by glass pouring or glass glazing. Regardless of the glass welding method, since the glass is heated to a high temperature above its softening point, glass erosion of the ferrite occurs at the interface between the ferrite and the glass, resulting in a difference between the optical gap length and the effective gap length. In addition, air bubbles may occur in the glass that forms the gap, and when processed into a magnetic head, air bubbles may be exposed on the sliding surface with the recording medium, and this may be the starting point for the ferrite crystal to fall off. There was also the problem of progressive deterioration of wear resistance. In order to solve this problem, it is necessary not only to improve the manufacturing method of the magnetic head to prevent glass erosion and bubble generation, but also to improve the glass itself to create a glass that inherently has less glass erosion and bubble generation. A composition is desperately needed. The preferable properties of this glass composition for magnetic heads are that the erosion of ferrite is as small as possible, and that the effective gap length can be as close to the set value as possible;
It can be strongly bonded with less air bubbles in the glass during welding, has low alkali elution and is chemically stable, and has a thermal expansion coefficient within the range of ±15×10 -7 /℃ compared to ferrite. There is something
One example of this is that it has wear resistance for magnetic recording media comparable to that of ferrite in magnetic head cores. The object of the present invention is to provide a glass composition for magnetic heads having the above-mentioned properties. Intended for glass compositions. That is, this invention includes SiO2 15wt% to 22wt%, B2O3 18wt % to 28wt%, Al2O3 2wt % to 6wt%, BaO 3wt% to 8wt%, MnO2 0.2wt% to 4wt%, Contains at least one of NaO 4wt% to 10wt% and K 2 O 2wt% to 4wt%, and the remainder is substantially ZnO.
A glass composition for a magnetic head, characterized in that it further contains at least one of LiO 2 2wt% or less, MgO 2wt% or less, and CaO 5wt% or less, the remainder being substantially
This is a glass composition characterized by consisting of ZnO. The reason for limiting the composition range of the glass composition according to the present invention will be explained below. If SiO 2 exceeds 22wt%, the coefficient of thermal expansion becomes too small, and the softening point of the glass becomes high, making it easy to corrode ferrite.If SiO 2 is less than 15wt%, it lacks chemical stability. 15wt%~
It is assumed to be 22wt%. B 2 O 3 is included to adjust the glass viscosity and suppress the tendency to devitrify, but if it exceeds 28 wt%, the thermal expansion coefficient becomes too small, and if it is less than 18 wt%, the thermal expansion coefficient becomes too large, and Mn- Since the thermal expansion coefficient of Zn ferrite exceeds the range of ±15×10 -7 /°C, the content is set at 18 wt% to 28 wt%. When Al 2 O 3 exceeds 6wt%, the viscosity increases,
If the glass welding temperature becomes too high, glass erosion of the ferrite will easily occur, and if it is less than 2wt%, the water resistance of the glass will deteriorate, so 2wt% or more
The content is 6wt%. Since BaO has the effect of reducing the tendency to devitrify,
The content should be 3wt% to 8wt%. The content of MnO 2 is a feature of the glass composition according to the present invention, and it is effective in suppressing the cell reaction during vitrification and preventing the formation of bubbles in the glass. If it is less than 4 wt%, the effect of preventing bubble generation will be small, and if it exceeds 4 wt%, the reducing property will be large and cause damage to the crucible etc. during melting, so the content should be 0.2 wt% to 4 wt%. Na 2 O and K 2 O are contained to promote vitrification. If Na 2 O exceeds 10 wt%, it tends to react with ferrite, which is undesirable. If it is less than 4 wt%, devitrification tends to occur in the glass. This causes variations in glass crystallization and reduces glass strength.
The content should be 4wt% to 10wt%. If K 2 O exceeds 4wt%, the coefficient of thermal expansion is too large, and if it is less than 2wt%, the water resistance deteriorates.
The content should be 2wt% to 4wt%. ZnO is the main component of the glass composition according to the present invention, suppresses the reaction of glass with ferrite,
It has the effect of making the coefficient of thermal expansion of glass similar to that of ferrite. Also, the optimal amount of ZnO is
It is 26wt% to 30wt%. Furthermore, in the glass composition according to the invention,
LiO, MgO, CaO to improve water resistance of glass
LiO contains at least one of the following:
If it exceeds 2wt%, devitrification phenomenon will occur, causing variations in properties such as the coefficient of thermal expansion, which is undesirable.
Also, MgO exceeding 2wt%, CaO exceeding 5wt%
are undesirable because they increase the viscosity of the glass and accelerate the tendency to devitrify.
MgO2wt% or less, CaO5wt% or less. Examples are shown below. It has the composition and thermal expansion coefficient shown in Table 1.
A pair of boat-shaped cores 1 and 2 shown in FIG. 1 were prepared from Mn--Zn ferrite material, and the gap forming surface on the side having the notch of each boat-shaped core was precisely polished. A pair of boat-shaped cores 1 and 2 are connected to spacers 3 and 4, respectively.
Assemble the polished surfaces facing each other through the core 1,
Four types of glass rods 5 according to the present invention, labeled a to d, having compositions, softening points, and thermal expansion coefficients shown in Table 2 were placed near the apex portion of No. 2, respectively. Next, the glass rod 5 used was heated to 730°C, which is above the softening point, and held for 10 minutes to melt the glass, filling the gap part 6 with glass by capillary action, and then cooling and solidifying it. Finished with the magnetic head material shown in the figure. Note that the heating was performed in an N 2 atmosphere to prevent deterioration of the Mn-Zn ferrite due to oxidation. In addition, under the above-mentioned conditions and glass pouring method, comparative examples (e, f) glass rods other than the compositions of the present invention having the compositions, softening points, and coefficients of thermal expansion shown in Table 2 were used, and similar magnetic head materials were made. Created. Next, the generation of bubbles in the glass of the gap portion 6, the amount of alkali elution, and the Vickers hardness of the magnetic head material obtained were examined. The results are shown in Table 3. Note that the bubble generation status was evaluated by the bubble generation rate (%), which is the ratio of the bubble surface area to the exposed glass surface area. As is clear from the test results in Tables 2 and 3, the glass composition according to the present invention has Mn-Zn
It has a thermal expansion coefficient close to that of ferrite, and it can be seen that there is almost no bubble generation even in the gap part, which is significantly less than that of the comparative example glass composition. In addition, the amount of alkali elution was extremely small and the material was chemically stable, there was almost no erosion of ferrite, and the effective gap length was close to the design value.
【表】【table】
【表】【table】
第１図から第３図は、磁気ヘツドの製造方法を
示すコアの説明図である。
１，２……舟型コア、３，４……スペーサー、
５……ガラス棒、６……ギヤツプ部。
1 to 3 are explanatory diagrams of a core showing a method of manufacturing a magnetic head. 1, 2...boat-shaped core, 3, 4...spacer,
5...Glass rod, 6...Gap part.
Claims (1)
％のうち少なくとも１種を含有し残部ZnO及び不
可避的不純物からなることを特徴とする磁気ヘツ
ド用ガラス組成物。 ２ SiO2 15wt％〜22wt％、 B2O3 18wt％〜28wt％、 Al2O3 2wt％〜6wt％、 BaO 3wt％〜8wt％、 MnO2 0.2wt％〜4wt％、 及びNa2O 4wt％〜10wt％、K2O 2wt％〜4wt
％のうち少なくとも１種を含有、 さらに LiO2 2wt％以下、 MgO 2wt％以下、CaO 5wt％以下のうち少な
くとも１種を含有し、 残部ZnO及び不可避的不純物からなることを特
徴とする磁気ヘツド用ガラス組成物。[Claims] 1 SiO 2 15wt% to 22wt%, B 2 O 3 18wt% to 28wt%, Al 2 O 3 2wt% to 6wt%, BaO 3wt% to 8wt%, MnO 2 0.2wt% to 4wt% , and Na2O 4wt%~10wt%, K2O 2wt%~4wt
%, and the remainder consists of ZnO and unavoidable impurities. 2 SiO 2 15wt% to 22wt%, B 2 O 3 18wt% to 28wt%, Al 2 O 3 2wt% to 6wt%, BaO 3wt% to 8wt%, MnO 2 0.2wt% to 4wt%, and Na 2 O 4wt% %~10wt%, K2O 2wt%~4wt
%, and further contains at least one of LiO 2 2wt% or less, MgO 2wt% or less, and CaO 5wt% or less, with the remainder consisting of ZnO and inevitable impurities. glass composition.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9444483A JPS59223248A (en) | 1983-05-27 | 1983-05-27 | Glass composition for magnetic head |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9444483A JPS59223248A (en) | 1983-05-27 | 1983-05-27 | Glass composition for magnetic head |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS59223248A JPS59223248A (en) | 1984-12-15 |
| JPS6311291B2 true JPS6311291B2 (en) | 1988-03-14 |
Family
ID=14110425
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP9444483A Granted JPS59223248A (en) | 1983-05-27 | 1983-05-27 | Glass composition for magnetic head |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS59223248A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4300786B2 (en) | 2001-12-21 | 2009-07-22 | 昭栄化学工業株式会社 | Glass and conductive paste using the same |
-
1983
- 1983-05-27 JP JP9444483A patent/JPS59223248A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS59223248A (en) | 1984-12-15 |
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