JP2003192379A - Glass-containing composition for conductor and glass-containing conductor - Google Patents

Abstract

(57) [Summary] An object of the present invention is to contain glass suitable for a glass magnetic disk holding member.
Proposal of glass-containing composition suitable for conductor and its production
Offering. 30% to 60% glass powder by mass percentage,
Specific resistance ρ ≦ 1 × 10⁴No Ω · cm and melting point ≧ 600 ° C
Aircraft powder (preferably oxidized oxide doped with antimony
Powder) 40-70%, ρ> 1 × 10⁴Ω · cm inorganic
It consists of 0 to 10% of the product powder, the glass powder is Si
O₂: 45-70%, Li₂O + Na₂O + K ₂O: 1
0 to 25%, MgO + CaO + SrO + BaO: 10
30%, Al₂O₃: 1 to 10% conductor glass
-Containing composition. In addition, a gas obtained by firing the composition.
A lath-containing conductor.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a glass-containing conductor suitable for a glass magnetic disk holding member such as a spacer or a clamp of a glass magnetic disk device, and a glass-containing composition for a conductor suitable for producing the conductor. .

[0002]

2. Description of the Related Art A magnetic disk device, which is one of auxiliary storage devices for computers, is roughly divided into a magnetic disk,
It consists of a read / write head, an access arm and an actuator. A magnetic disk is a donut plate-shaped substrate whose both surfaces are coated with a magnetic material, and in recent years, a glass magnetic disk in which the substrate is a glass substrate has been widely used.

In the magnetic disk device, a plurality of magnetic disks are attached to the hub portion so as to be superposed at a predetermined interval. That is, the hub portion is composed of a spindle connected to a rotary drive mechanism of the magnetic disk device, a bearing for receiving the spindle, and a hub body connected to the spindle, and the plurality of magnetic disks are separated by a ring-shaped spacer. And is inserted into the hub body and fixed by a disc-shaped clamp, shim, or the like. The predetermined spacing between the magnetic disks is determined by the thickness of the ring-shaped spacer.

The hub body is made of a metal having an average linear expansion coefficient α of 100 × 10 ⁻⁷ / ° C. or more at 50 to 350 ° C., whereas α of a glass magnetic disk is typically 7
It is 0 × 10 ⁻⁷ / ° C. to 80 × 10 ⁻⁷ / ° C. By the way, the temperature of the glass magnetic disk holding member such as the spacers, clamps, and shims rises when the magnetic disk rotates.
At this time, if these holding members are made of the same metal as the hub body, α of the holding member and the glass magnetic disk is
Due to the large difference between the two, the glass magnetic disk may be distorted or the parallelism between the glass magnetic disks may be reduced.

In order to solve this problem, it has been proposed to use an alumina ceramic having α of about 80 × 10 ⁻⁷ / ° C. as the holding member.

[0006]

The holding member using the alumina ceramics solves the problems such as the occurrence of distortion in the glass magnetic disk and the decrease in the parallelism between the glass magnetic disks. However, noise is generated during reading or writing. The problem arises. It is considered that this is because the glass magnetic disk is charged because the alumina ceramic is an electrical insulator. An object of the present invention is to provide a glass-containing conductor for solving the above problems and a glass-containing composition for a conductor used in the production thereof.

[0007]

The present invention provides a mass percentage table.
Essentially, glass powder 30-60% at 20 ° C
Specific resistance ρ is 1 × 10⁶Ω · cm or less and melting point 600
40 to 70% of inorganic powder having a temperature of ℃ or more, ρ is 1 × 10
⁶Inorganic powder 0 to 10%, which is more than Ω · cm
The glass powder is represented by the following percentage by mass of oxide standard.
Essentially SiO _Two: 45-70%, Li_TwoO + Na_Two
O + K_TwoO: 10 to 25%, MgO + CaO + SrO +
BaO: 10-30%, Al_TwoO_Three: 1-10%, B_Two
O_Three: 0 to 15%, ZnO: 0 to 15%, SnO_Two+ C
eO_Two+ TiO_Two+ ZrO_Two: 0-10%, consisting of
And a glass-containing composition for a conductor, which is characterized by
Inventive composition A).

Further, in terms of mass percentage, the glass powder is essentially 30 to 60%, and the specific resistance ρ at 20 ° C. is 1 × 10.
The specific resistance at 20 ° C. consists of 40 to 70% of inorganic powder having a melting point of ⁶ Ω · cm or less and 600 ° C. or more, and 0 to 10% of inorganic powder having a ρ of more than 1 × 10 ⁶ Ω · cm. ρ is 1 × 10 ⁶ Ω · cm or less and melting point is 600 ° C.
Provided is a glass-containing composition for a conductor, wherein the above-mentioned inorganic powder contains antimony-doped tin oxide powder (composition B of the present invention). Also,
Provided is a glass-containing conductor obtained by firing the glass-containing composition for a conductor.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The glass-containing composition for a conductor of the present invention (hereinafter simply referred to as the composition of the present invention) is usually fired to obtain a glass-containing conductor. For example, the composition of the present invention is filled in a mold, pressed into a press-molded article having a desired shape, and then heated to a temperature in the range of 900 ° C or lower, typically 600 to 900 ° C. To obtain a glass-containing conductor. The glass-containing conductor thus obtained is the glass-containing conductor of the present invention (hereinafter simply referred to as the conductor of the present invention), and is processed into a desired shape if necessary, and a glass magnetic disk such as a spacer, a clamp or a shim. Used as a holding member.

The composition of the present invention is not essential to the composition of the present invention for the purpose of increasing the efficiency of filling the mold, improving the workability of the work of filling the mold, and improving the strength of the press-molded product. You may add and granulate and granulate. in this case,
It is preferable to perform calcination for the purpose of completely removing the binder before the calcination. The calcination is typically performed by heating to 400 to 500 ° C. in the atmosphere.

The amount of the binder added is preferably 6 parts by mass or less based on 100 parts by mass of the composition of the present invention.
If it exceeds 6 parts by mass, it may be difficult to completely remove the binder during pre-baking. Further, when the binder is added, it is preferably 1 part by mass or more. If it is less than 1 part by mass, the effect of improving the strength of the press-molded product may be small. The binder is preferably one or more polymer resins selected from the group consisting of polyethylene glycol, polyethylene oxide and acrylic resins.

Further, prevention of adhesion to the mold during press molding,
The composition of the present invention for increasing the density of the press-formed product,
Although not essential, a release agent may be added. The amount of the release agent added is preferably 2 parts by mass or less, based on 100 parts by mass of the composition of the present invention. If it exceeds 2 parts by mass, it may be difficult to completely remove the release agent during calcination.
When a release agent is added, it is preferably 0.05 part by mass or more. The release agent is preferably one or more organic substances selected from the group consisting of stearic acid, metal stearates, lauric acid, metal laurates, liquid paraffin and paraffin wax.

Next, the components of the composition of the present invention will be described using mass percentage notation. In the present specification, unless otherwise specified, the percentage by mass is used. Glass powder is an essential component. If it is less than 30%, the sinterability will decrease. It is preferably at least 35%. If it exceeds 60%, the specific resistance of the glass-containing conductor becomes high. It is preferably 58% or less.

The glass powder may be obtained by rapidly cooling molten glass into flake-shaped glass and crushing it with a ball mill or the like, or by crushing the molten glass with water and crushing it. The mass average particle diameter of glass powder is typically 1 to 5 μm
Is.

The softening point of the glass powder is preferably 750 ° C. or lower. If it exceeds 750 ° C, the firing temperature becomes too high, and the manufacturing cost may increase. More preferably, it is 720 ° C. or lower. The softening point is preferably 55.
The temperature is 0 ° C or higher, more preferably 580 ° C or higher.

The average linear expansion coefficient α of the glass powder at 50 to 350 ° C. is 85 × 10 ^{−7 to} 125 × 10 ⁻⁷ / ° C.
Is preferred. If it is less than 85 × 10 ⁻⁷ / ° C., expansion matching with the metal of the hub body may be difficult. More preferably, it is 90 × 10 ⁻⁷ / ° C. or higher.
If it exceeds 125 × 10 ⁻⁷ / ° C., expansion matching with the glass magnetic disk may be difficult. It is more preferably 120 × 10 ⁻⁷ / ° C. or less.

The composition of the glass powder in the composition A of the present invention will be described below. The glass powder in the composition B of the present invention is also preferably the glass powder in the composition A of the present invention. SiO ₂ is a glass network former and is essential. If it is less than 45%, the chemical stability is lowered, and the softening point becomes too low, so that the reaction with the conductive filler described later, for example, the powder of tin oxide on which antimony is doped, proceeds to obtain the desired conductivity. Absent. It is preferably at least 48%. If it exceeds 70%, the softening point tends to be high, and a highly dense glass-containing conductor cannot be obtained. It is preferably 68% or less.

Li ₂ O, Na ₂ O and K ₂ O are all components for lowering the softening point or increasing α, and must contain at least one of these three components. I won't. The total of the contents of these three components L
If i ₂ O + Na ₂ O + K ₂ O is less than 10%, the softening point becomes high. It is preferably at least 13%. If it exceeds 25%, the softening point tends to be too low. It is preferably 23% or less.

MgO, CaO, SrO and BaO are all components for increasing α, and must contain at least one of these four components. The total content of these four components MgO + CaO + SrO + BaO
Is less than 10%, α is small. It is preferably at least 13%. If it exceeds 30%, the glass tends to devitrify. It is preferably 25% or less.

Al ₂ O ₃ is a component for improving chemical stability and is essential. If it is less than 1%, the chemical stability is lowered. It is preferably at least 3%. If it exceeds 10%, the glass tends to devitrify. It is preferably 9% or less.

B ₂ O ₃ and ZnO are not essential, but may be contained up to 15% in order to lower the softening point. If it exceeds 15%, the softening point tends to be too low. Each is preferably 10% or less.

SnO_Two, CeO_Two, TiO_TwoAnd Zr
O_TwoIs not essential, but the chemical stability of the glass
In order to improve the total content of these four components SnO_Two+ C
eO _Two+ TiO_Two+ ZrO_TwoContained within 10% or less
You may. If it exceeds 10%, the softening point tends to be too high. Good
It is preferably 5% or less.

The glass powder consists essentially of the above components, but may contain other components as long as the object of the present invention is not impaired. The total amount of the other components is preferably 5% or less. As the other components, La is
Components such as ₂ O ₃ , P ₂ O ₅ , V ₂ O _{5 and the} like for reducing the viscosity at the time of glass melting are exemplified. It is preferable that neither lead nor cadmium is contained.

The specific resistance ρ at 20 ° C. is 1 × 10 ⁶ Ω.
Inorganic powder having a melting point of not more than cm and a melting point of 600 ° C. or more (hereinafter referred to as conductive powder) is a component for increasing the conductivity of the glass-containing conductor obtained by firing the composition of the present invention, that is, reducing ρ. It is an ingredient for making it and is essential. The melting point is read as the glass transition point when the inorganic substance is glass, and as the sublimation point when the inorganic substance is sublimated. If the conductive powder content is less than 40%, the conductivity of the glass-containing conductor will decrease. It is preferably at least 42%. If it exceeds 70%, the sinterability will decrease. It is preferably 67% or less.

The mass average particle size of the conductive powder is typically 1
Is about 3 μm. Ρ of the conductive powder is preferably 1 × 1
0 ⁵ Ω · cm or less, more preferably 1 × 10 ⁴ Ω · cm
It is particularly preferably 1 × 10 ³ Ω · cm or less.
The melting point of the conductive powder is preferably 1000 ° C. or higher, more preferably 1200 ° C. or higher, and typically 1600 ° C. or higher.

The conductive powder is an inorganic powder selected from the group consisting of antimony-doped tin oxide powder (hereinafter referred to as Sb-doped tin oxide powder), tin oxide powder, carbon powder, ZnO powder and FeO powder. 1
It is preferably at least one species. Among them, Sb-doped tin oxide powder is particularly preferable because it can form a stable mixed state with glass at a high temperature of about 900 ° C.

The antimony content in the Sb-doped tin oxide powder is preferably 1 to 4%. If it is less than 1%, ρ may increase. It is more preferably at least 2%. If it exceeds 4%, ρ hardly decreases. It is more preferably 3% or less.

The conductive powder in the composition B of the present invention is S
Contains b-doped tin oxide powder. The conductive powder is S
It is preferably a b-doped tin oxide powder. The content of Sb-doped tin oxide powder in the composition of the present invention is 40
It is preferably ˜70%. More preferably 42%
It is above, and is 67% or less.

An inorganic powder (hereinafter referred to as insulating powder) having ρ of more than 1 × 10 ⁶ Ω · cm is not essential, but may be contained up to 10% for coloring or the like. If it exceeds 10%, the denseness of the glass-containing conductor decreases. It is preferably 5% or less. As the insulating powder for coloring, chromium oxide, iron-manganese oxide, copper-chromium oxide,
A heat resistant pigment such as a cobalt-based oxide may be used. The mass average particle diameter of the heat resistant pigment is typically 0.5 to 2 μm.

Ρ of the conductor of the present invention is preferably 1 × 10.
^{It is 9} Ω · cm or less, more preferably less than 1 × 10 ⁸ Ω · cm, particularly preferably 3 × 10 ⁷ Ω · cm or less, and most preferably 1 × 10 ⁷ Ω · cm or less. Further, α of the conductor of the present invention is 60 × 10 ⁻⁷ / ° C. to 100 × 10 ⁻⁷ / ° C.
Is preferred. If it is less than 60 × 10 ⁻⁷ / ° C., expansion matching with the metal of the hub body may be difficult. It is more preferably 80 × 10 ⁻⁷ / ° C. or higher.
If it exceeds 100 × 10 ⁻⁷ / ° C., expansion matching with the glass magnetic disk may become difficult. It is more preferably 90 × 10 ⁻⁷ / ° C. or less.

[0031]

[Examples] The raw materials were mixed and mixed so that the compositions shown in the percentage by mass column in the columns from SiO ₂ to Al ₂ O _{3 in the} table were mixed and melted at 1400 to 1550 ° C for 1 to 3 hours using a platinum crucible. To obtain molten glass, and the molten glass was rapidly cooled to obtain flaky glass. Next, the flaky glass is crushed with a crushing material such as a ball mill so that the mass average particle diameter is 1 to 5
A glass powder of μm was obtained. The α and the softening point of the obtained glass powder are respectively α _g (unit: 10 ⁻⁷ / ° C.) in the table,
It is shown in the column of T _S (unit: ° C).

Next, the glass powder, the conductive powder and the insulating powder thus obtained are blended and mixed so as to have a composition shown in the column of glass to insulating powder in the table by mass percentage and mixed powders 1 to 9 are mixed. Got In the mixed powders 1 to 6, 8 and 9, Sb-doped tin oxide powder was used as the conductive powder.
The antimony content in the Sb-doped tin oxide powder is S in the table.
In the column of b, the mass percentage is shown. In the mixed powder 7, tin oxide powder was used as the conductive powder. Further, in the mixed powders 2, 3, and 7, heat-resistant pigments composed of cobalt-based oxides, iron-manganese-based oxides, and cobalt-based oxides were used as insulating powders.

25 g for each of the mixed powders 1-9
Was weighed and pressed at 20 ° C. in the atmosphere at a pressure of 300 to 500 kgf / cm ² (29.4 to 49.0 MPa) to obtain a size of 15 mm × 15 mm and a thickness of 3.0 to 3.
A 3 mm press molded product was obtained. 800 ℃ in the atmosphere
The glass-containing conductor was fired by holding for 0.5 hour. Ρ and α of the obtained glass-containing conductor are shown in Table
(Unit: Ω · cm) and α _C (unit: 10 ⁻⁷ / ° C.).

The denseness of the obtained glass-containing conductor was evaluated by the following two methods. First, the appearance was visually observed. The results are shown in the table, in which no large pores or cracks are observed, and x is not. As another method, the calculated value of the glass-containing conductor density was obtained, and the ratio R of the measured value of the glass-containing conductor density to that was calculated. R is preferably 0.97 or more. The calculated value was calculated from the densities of the glass powder, the conductive powder and the insulating powder, and their contents.

[0035]

[Table 1]

[0036]

According to the present invention, a glass-containing conductor having a small specific resistance and suitable for a glass magnetic disk holding member can be obtained. Further, a glass-containing composition for a conductor is obtained which can be obtained by firing at a temperature of 900 ° C. or lower.

Continued front page    F-term (reference) 4G062 AA10 BB01 DA05 DA06 DB03                       DC01 DC02 DC03 DC04 DD01                       DE01 DE02 DE03 DE04 DF01                       EA01 EA02 EA03 EA04 EB01                       EB02 EB03 EB04 EC01 EC02                       EC03 EC04 ED01 ED02 ED03                       ED04 EE01 EE02 EE03 EE04                       EF01 EF02 EF03 EF04 EG01                       EG02 EG03 EG04 FA01 FB01                       FB02 FB03 FC01 FC02 FC03                       FD01 FE01 FE02 FE03 FF01                       FG01 FH01 FJ01 FK01 FL01                       FL02 FL03 GA01 GA10 GB01                       GC01 GD01 GE01 HH01 HH03                       HH05 HH07 HH09 HH11 HH13                       HH15 HH17 HH20 JJ01 JJ03                       JJ05 JJ07 JJ10 KK01 KK03                       KK05 KK07 KK10 MM16 MM23                       NN24

Claims (8)

[Claims] 1. Essentially, in terms of mass percentage, glass powder 3
0-60%, specific resistance ρ at 20 ° C is 1 × 10 ⁶ Ω ・
cm or less and a powder of an inorganic substance having a melting point of 600 ° C. or more 4
0 to 70% and 0 to 10% of an inorganic powder having ρ of more than 1 × 10 ⁶ Ω · cm, and the glass powder is essentially represented by the following oxide-based mass percentage: SiO ₂ 45 to 70
%, Li ₂ O + Na ₂ O + K ₂ O 10-25
%, MgO + CaO + SrO + BaO 10-30
%, Al ₂ O ₃ 1-10
%, B ₂ O _{3 0 to} 15
%, ZnO 0-15
%, SnO ₂ + CeO ₂ + TiO ₂ + ZrO ₂ 0-10
%, And a glass-containing composition for conductors. 2. The inorganic powder having a ρ of 1 × 10 ⁶ Ω · cm or less and a melting point of 600 ° C. or more is antimony-doped tin oxide powder, tin oxide powder, carbon powder, ZnO powder and FeO. The glass-containing composition for a conductor according to claim 1, which is one or more kinds of inorganic powders selected from the group consisting of powders. 3. The inorganic powder having a ρ of 1 × 10 ⁶ Ω · cm or lower and a melting point of 600 ° C. or higher contains antimony-doped tin oxide powder. The conductor-containing glass-containing composition according to item 2. 4. Essentially, in terms of mass percentage, glass powder 3
0-60%, specific resistance ρ at 20 ° C is 1 × 10 ⁶ Ω ・
cm or less and a powder of an inorganic substance having a melting point of 600 ° C. or more 4
0 to 70%, [rho is 0-10% inorganic powder is 1 × 10 ⁶ Ω · cm greater, made from inorganic powder specific resistance [rho is not more than 1 × 10 ⁶ Ω · cm at the 20 ° C. is A glass-containing composition for a conductor, which contains tin oxide powder doped with antimony. 5. The glass-containing composition for conductor according to claim 2, wherein the content of antimony in the powder of tin oxide doped with antimony is 1 to 4% in terms of mass percentage. 6. The glass-containing composition for a conductor according to claim 1, wherein the glass powder has a softening point of 750 ° C. or lower. 7. A glass-containing conductor obtained by firing the glass-containing composition for a conductor according to claim 1. 8. The glass-containing conductor according to claim 7, wherein the firing is performed at a temperature of 900 ° C. or lower.