JP3190961B2 - Low temperature fusing glass composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates, can <br/> Rukoto be fused at 550 ° C. or less, and superior in chemical durability, fusion of a magnetic material for a magnetic head, in particular, The present invention relates to a low-temperature fusing glass composition suitable for fusing a ferrite head having a metal magnetic film such as a sendust thin film formed on its surface.

[0002]

2. Description of the Related Art A magnetic head such as a video, floppy or hard disk is formed by fusing a pair of core materials made of a magnetic material with glass and integrating them.

[0003] Glass used for fusion of the magnetic material for the magnetic head, which wear properties as shown below in satisfaction are preferred. 1) It has excellent chemical durability so as not to be affected by water, high pH polishing liquid, organic solvent and the like. 2) Low reactivity with magnetic materials, generally ferrite. 3) The glass is stable, and no devitrified matter (crystal) is deposited in the glass during the heat treatment process.

In recent years, as the density of magnetic recording has increased, recording media having a high coercive force have been used. In order to perform recording on such a medium, a metallic magnetic material such as sendust is placed near a gap of ferrite. A head having a metal-in-gap structure in which a film is formed has been used. Such a head needs to be fused so as not to impair the magnetic properties of the metal magnetic film, and for this purpose, it is preferable to fuse at a temperature of 550 ° C. or less.

For this reason, various studies have been made on low-temperature fusing glass compositions which can be fused at a temperature of 550 ° C. or lower.
JP-A-63-170240, JP-A-1-308844
And the like. These include PbO, B ₂ O ₃ ,
The fusing temperature was lowered by increasing the content of alkali oxides such as Na ₂ O, K ₂ O and Li ₂ O.

[0006]

However, when the content of PbO, B ₂ O ₃ or alkali oxide is increased in order to lower the fusing temperature, the above characteristics 1) to 3) are deteriorated. . In particular, in the manufacturing process of the magnetic head, since there is a step of polishing using water, a high pH polishing liquid, and an organic solvent after fusing with glass, if the chemical durability of the glass is deteriorated, There is a problem that the portion is eroded to cause a step in the sliding portion of the head, and that the function of the head is impaired due to adhesion of eluted precipitates.

The present invention has been made in view of the above problems, and has as its object to be able to fuse at a temperature of 550 ° C. or less, to have excellent chemical durability, and to react with ferrite. It is an object of the present invention to provide a low-temperature fusing glass composition having a low resistance. That is, it can be used for fusing a magnetic material for a magnetic head, particularly for a ferrite head having a metal magnetic film such as sendust formed on its surface.
H polishing liquid, even when in contact with organic solvents, no problem or caused stepped in the sliding portion of the head glass portion is eroded, eluted precipitates adhered or impair the function of the head cold An object of the present invention is to provide a fusing glass composition.

[0008]

Means for Solving the Problems To achieve the above object,
The mainMing is, Mol%, PbO: 38-62%, Si
O_Two15-45%, B_TwoO_Three: 0 to 18%, ZnO and
// BaO: 0-5%, Al_TwoO_Three: 0-8%,K
_Two O: 1-2%,Li_TwoO, Na_TwoO, K_TwoChosen from O
One or more types:1~ 6%,ZrO _Two : 1-4%,Z
rO_TwoPassingAnd Nb_TwoO_Five Sum of:1~ 5%, justNb_TwoO_Five
Is 4% And not more than 550 ° CFusionYou
It is characterized by being able toFor magnetic head
Provide low temperature fusing glass composition for fusing magnetic materials
Do.

Hereinafter, the present invention will be described in more detail.

In the present invention, when the content of PbO is less than 38%, the fusing temperature of the glass rises, and 550 ° C.
In the case where the following fusion becomes difficult and exceeds 62%,
Vitrification becomes unstable, devitrified matter is easily deposited, and hardness is remarkably reduced. When the content of SiO ₂ is less than 15%, vitrification becomes insufficient. When the content exceeds 45%, fusion at 550 ° C. or lower becomes difficult. Further, B ₂ O ₃
Is more than 18%, the chemical durability is significantly degraded, and when ZnO and / or BaO is more than 5%,
Affects the transparency of the glass . When Al ₂ O ₃ exceeds 8%, fusion at 550 ° C. or less becomes difficult, and Li
₂ O, Na ₂ O, when one or more kinds selected from K ₂ O exceeds 6%, chemical durability of deterioration remarkable arbitrariness. ZrO
_When the total content of ₂ and Nb ₂ O ₅ is less than 1 %, there is no effect of improving chemical durability, and when the total content exceeds 5%,
The glass becomes unstable and devitrifies.

The low-temperature fusing glass composition of the present invention has a molar percentage of PbO: 38-58% and SiO ₂ : 27-44.
_{%, B 2 O 3: 4~10} %, ZnO and / or BaO: 0
３3%, Al ₂ O ₃ : 1 to 4%, K ₂ O: 1 to 2%, Li ₂
One or more selected from O, Na ₂ O, and K ₂ O: 1
To 4%, ZrO ₂ and / or Nb ₂ O _5: it is more preferably made of a is the composition 1-3%. In the above description, when simply described as%, it means mol%.

The low-temperature fusing glass composition of the present invention contains components other than those described above as long as the effects of the present invention are not impaired.
For example, Bi ₂ O ₃ , Fe ₂ O ₃ , MnO or the like can be blended.

The low-temperature fusing glass composition of the present invention having the above composition is capable of fusing at 550 ° C. or lower and has chemical durability, ie, water, high pH polishing solution, organic Excellent durability when contacted with solvent and low reactivity with ferrite. Therefore, by molding this glass composition into, for example, a glass rod or a square rod having a predetermined shape and size, fusion of a magnetic material for a magnetic head, in particular, metal in which a metal magnetic film such as sendust is formed. It can be used for fusing a magnetic material for a magnetic head having a gap structure.

[0014]

In the glass composition, PbO, B ₂ O ₃ , L
It is generally known that the melting point of glass decreases as the amount of alkali oxides such as i ₂ O, Na ₂ O, and K ₂ O increases. However, if the melting point is lowered in this manner, the characteristics described in 1) to 3) above will be reduced when used for fusing a magnetic material for a magnetic head. In other words, in the process of fusing the magnetic material with glass and then polishing using water, a high pH polishing solution, an organic solvent, etc., the glass portion is eroded, causing a step in the sliding portion of the head or elution. There is a problem that the substance is deposited and adheres, thereby impairing the function of the head.

[0015] However, the glass composition of the present invention comprises ZrO 2
By containing ₂ and / or Nb ₂ O ₅ , chemical durability is improved, and erosion by water, a high pH polishing liquid, an organic solvent or the like is prevented. In addition, the reactivity with ferrite, which is a magnetic material, is reduced, and it is possible to prevent the magnetic head from deteriorating by reacting with ferrite. Therefore, 5
A glass composition that can be fused at a temperature of 50 ° C. or less and has excellent chemical durability can be obtained. Particularly, for a magnetic head having a metal-in-gap structure in which a metal magnetic film such as sendust is formed. This is suitable for fusing magnetic materials.

[0016]

EXAMPLES Example _{1~ 6 PbO, SiO 2, B} 2 O 3, ZnO, BaO, Al
₂ O ₃ , Li ₂ O, Na ₂ O, K ₂ O, ZrO ₂ , Nb ₂ O
_The raw materials were blended so that ₅ had the ratio shown in Table 1, and after melting in a platinum crucible at 1000 to 1200 ° C. for 1 hour, the mixture was poured out onto an iron plate to obtain a glass block.

[0017] Examples 4 and 5 Example, Examples 1, 2, 3, 6 is the ratio <br/> Comparative Examples.

With respect to the glass blocks of Examples 1 to 6 thus obtained, their glass transition point (hereinafter, simply referred to as transition point), softening point, sealing temperature, coefficient of thermal expansion, water resistance, alkali resistance, reactivity with ferrite. , it was measured.

In the above, the transition point, softening point, and seal temperature are measured by differential thermal analysis (DTA method), and the coefficient of thermal expansion is determined by measuring the average expansion coefficient from 30 ° C. to the transition point by a differential dilatometer. ^It was determined in units of ^-7 / C. Water resistance was 1 cm after immersion in distilled water at 95 ° C. for 1 hour.
^The alkali resistance is expressed by 1 cm ² after immersion in a 5% NaOH aqueous solution at 50 ° C. for 1 hour.
It was expressed by weight reduction per unit.

Further, the reactivity with the ferrite was determined by placing a glass block cut into a size of about 3 × 3 × 10 mm on the ferrite, and keeping the glass at a temperature for fusing the glass in an electric furnace in an N ₂ atmosphere for 20 minutes. Thereafter, the mixture was cooled in a furnace to room temperature, and then the cross section of the glass ferrite was polished and the boundary between the glass and the ferrite was observed with a microscope of 500 times. Then, the sample having irregularities due to the reaction with the glass on the ferrite surface was evaluated as x, and the sample without irregularities was evaluated as ○. Table 1 shows the results.

[0021]

[Table 1]

[0022] From the results shown in Table 1, Example 4, 5 of the glass is a real 施例, compared with glass of Example 1, 2, 3, and 6 is the ratio Comparative Examples, water resistance, alkali resistance, the ferrite It can be seen that the reactivity is significantly improved.

[0023]

As described above, the glass composition of the present invention can be fused at 550 ° C. or lower, has excellent chemical durability, and has low reactivity with ferrite. Therefore, by molding this glass composition into a glass rod or square rod of a predetermined size, it is particularly effective for fusing a magnetic material for a magnetic head having a metal-in-gap structure in which a metal magnetic film such as sendust is formed. Can be used.

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI C03C 3/108 C03C 3/108 8/24 8/24 (56) References JP-A-61-101432 (JP, A) JP-A JP-A-63-170240 (JP, A) JP-A-1-138151 (JP, A) JP-A-3-170345 (JP, A) JP-A-3-103337 (JP, A) JP-A-54-97616 (JP, A) , A) JP-A-51-229698 (JP, A) JP-B-42-17837 (JP, B1) (58) Fields investigated (Int. Cl. ⁷ , DB name) C03C 8/10 C03C 3/07 C03C 3/102 C03C 8/24

Claims (1)

(57) [Claims] 1. PbO: 38-62% in mole%, SiO
_{2: 15~45%, B 2 O} 3: 0~18%, ZnO and /
Or _{BaO: 0~5%, Al 2 O} 3: 0~8%, K 2 O:
_{1~2%, Li 2 O, Na} 2 O, one or two or more selected from _{K 2 O: 1 ~6%,} ZrO 2: 1~4%, ZrO 2
Total及beauty _{N b 2 O 5: 1 ~5} %, however Shi N b ₂ O ₅ 4%
A magnetic material for a magnetic head, having a composition not exceeding 550 ° C. and capable of being fused at 550 ° C. or lower.
A low-temperature fusing glass composition used for fusing materials.