JPH0667775B2 - Crystallized glass and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention provides a thermal expansion coefficient and an improved thermal expansion curve suitable for a substrate material used in various electric device fields, for example, a magnetic head field. The present invention relates to a crystallized glass having the same and a manufacturing method thereof.

[Prior Art] A magnetic head is an important component for recording, reproducing, and erasing information in audio equipment, VTRs, computers, and the like, and demand has been increasing in recent years. In particular, with the increasing demand for miniaturization of these devices and high density of information, development of thin film magnetic heads applying thin film technology such as IC has been rapidly progressing.

This thin film magnetic head is formed by forming a thin film of a magnetic material on a substrate, and is made of Ni-Zn ferrite, Mn-Zn ferrite, permalloy (Fe-Ni), sendust (Fe-A).
The thin film such as 1-Si) and their amorphous materials have a function of recording, reproducing and erasing information, and the substrate has a sliding function as well as a support of the magnetic material. Therefore, the substrate itself has various characteristics. Requested. That is, (1) about 70 to 180 depending on the type of magnetic material in order to improve the adhesiveness with the magnetic material.
Selecting a coefficient of thermal expansion in the range of 10 ⁻⁷ / ° C.,
(2) It has a heat resistance of 600 ° C. or higher because a thin film forming work of a magnetic material is performed at a high temperature. Almost the same hardness, that is, having a Vickers hardness in the range of about 600 to 1150 kgf / mm ² , (4) The structure is dense, homogeneous, and fine, (5)
It is generally required that the quality is constant and the productivity is excellent.

Also, in the field of manufacturing other various electric devices, various components in which a crystalline or amorphous metal, alloy, metal oxide, or the like is adhered or formed into a thin film on a substrate are variously used. Is required to have a wide range of thermal expansion coefficient ranging from 40 to 220 × 10 ⁻⁷ / ° C. according to the above various materials.

As materials for these substrates, ceramics by a powder sintering method and crystallized glass by a melting method are candidates. However, sintered ceramics are complicated and expensive in process operations such as particle size adjustment of powders, and it is difficult to obtain dense ceramics having no pores.

In comparison with this, crystallized glass has an advantage that a dense glass can be easily obtained, and various kinds of glass that meet the above requirements are known. For example, Japanese Patent Application Laid-Open No. Sho 49-125419 discloses a crystallized glass having a high hardness and a high expansion obtained from a SiO ₂ —Li ₂ O—TiO ₂ glass. Further, Japanese Patent Laid-Open No. 60-180934 discloses that Si
_{O 2 -Li 2 O-Al 2} O 3 -Au-Ag-Cu system obtained from glass scientific processable high expansion glass ceramic body is disclosed. Furthermore, Japanese Examined Japanese Patent Publication 33-7543
In _{JP, SiO 2 -Al 2 O 3 -ZnO} -T
high expansion resulting from iO ₂ based glass, crystallized glass having high hardness is, Japanese Patent Publication No. Sho 46-16518, SiO ₂
A crystallized glass having high strength, which is obtained from a -Al ₂ O ₃ -RO-ZrO ₂ type glass, is disclosed in JP-A-59-20373.
No. 6 discloses that SiO ₂ —Al ₂ O ₃ —ZnO—ZrO.
High expansion glass-ceramics obtained from ₂ -TiO ₂ system glass are mentioned, respectively. However, although these crystallized glasses satisfy the required conditions for the expansion coefficient, they cause a large bend in the thermal expansion curve, and therefore have poor adhesion to magnetic materials and other materials, and various heat treatment conditions. Even if devised, there is a drawback that it is difficult to prevent the coarsening of crystal grains.

[Problems to be Solved by the Invention] An object of the present invention is to provide a crystallized glass and a method for producing the same, in which the flexibility of the thermal expansion curve is improved while satisfying the above-mentioned requirements. .

[Means for Solving Problems] The inventors of the present invention have conducted various test studies in order to achieve the above-mentioned object, and as a result, SiO ₂ -A containing a relatively large amount of ZnO.
In the 1 ₂ O ₃ —ZnO—TiO ₂ system, when heat treatment is applied to the raw glass containing a specific amount of the MgO component and the PbO component as essential components, the raw glass has an appropriate hardness and a wide range of thermal expansion coefficient, and further has a thermal expansion coefficient. It was possible to find that a crystallized glass was obtained in which the curve did not bend.

Further, when the raw glass of the above composition is used and subjected to a crystallization heat treatment at a predetermined temperature which is relatively low as a crystallization temperature, it has an appropriate hardness and a wide range of thermal expansion coefficient, and has a dense structure. It has been found that a crystallized glass having excellent properties and homogeneity and having improved flexibility of the thermal expansion curve can be easily obtained. The present invention has been made based on these findings.

The feature of the crystallized glass according to the first invention of the present application is that the weight% is
, SiO ₂ 30-65%, Al ₂ O ₃ 5-25%, Z
nO 10.5-40%, MgO 3.5-20%, P
bO 0.5-10%, CaO + SrO + BaO 0-
15%, TiO _{2 2 to} 15%, B ₂ O ₃ 0 to 10%, L
a ₂ O ₃ + Y ₂ O ₃ + Gd ₂ O ₃ + Ta ₂ O ₅ + Nb _{2
O 5 + WO 3 0~10%,} ZrO 2 + P 2 O 5 + SnO
₂ 0-5%, provided that _{ZrO 2 0~2.5%, P 2 O} 5 0
~ 5%, SnO ₂ 0-2%, As ₂ O ₃ + Sb ₂ O ₃ 0
˜2% and one or more fluorides of the metal elements of each of the above metal oxides in a total amount of 0 to 5% by heat treatment of a raw glass, and 40
It has a coefficient of thermal expansion in the range of ˜220 × 10 ⁻⁷ / ° C.

The crystallized glass composition of the present invention can be expressed on the basis of oxides like the original glass, but the reason why the composition range of the original glass is limited as described above will be described below.

That is, when the amount of the SiO ₂ component is less than 30%, the obtained crystallized glass product tends to have a coarse structure, and has poor chemical durability and hardness.
If it exceeds%, it becomes difficult to melt the raw glass.

If the amount of Al ₂ O ₃ component is less than 5%, the chemical durability and hardness of the product will be poor, and if it exceeds 25%, the amount of highly-expanded α-quartz and α-cristobalite crystal precipitation will decrease. It becomes difficult to obtain a desired high expansion product.

The ZnO component is a very important component that has the effect of producing crystals such as garnite containing ZnO as a constituent element by heat treatment of glass and improving the hardness of the product.
If the amount is less than 10.5%, the above effect cannot be obtained, and if it exceeds 40%, the glass becomes unstable and the crystal grains are likely to be coarsened by the heat treatment.

If the amount of the MgO component is less than 3.5%, the glass becomes unstable and the meltability deteriorates, and the hardness of the product decreases. Further, if it exceeds 20%, the crystal grains in the product become coarse and cracks and the like are likely to occur.

The PbO component and the CaO, SrO, and BaO components cause α- which causes a relatively remarkable bend around 200 ° C. of the expansion curve.
Prevents excessive precipitation of cristobalite crystals,
It is an important component that has been found to have an effect of preventing bending due to the phase transition of α-quartz at around 0 ° C. and obtaining a desired coefficient of thermal expansion, and this effect is particularly remarkable for the PbO component. These components also contribute to the improvement of the meltability of the glass and the stability of the glass during molding. However, if the amount of PbO component is less than 0.5%, the above effect is not sufficient, and P
10% of bO component is 1% of CaO, SrO and BaO
If the total amount of one kind or two or more kinds of components exceeds 15%, it becomes difficult to deposit desired crystals and the crystal grains become coarse. Further, in order to make the above effect remarkable, Mg
It is more desirable that the weight ratio of O: (PbO + CaO + SrO + BaO) be (1 to 3): 1. Figure 1 at the end shows SiO ₂ 49%, Al ₂ O ₃ 19%, Mg
O 7.0%, ZnO 19.7%, TiO ₂ 5%, A
A glass having a composition of s ₂ O ₃ 0.3% was heated at a rate of 4.6 ° C. /
And the thermal expansion curve (a) of the crystallized glass obtained by heating at 1100 ° C. for 120 minutes, and using the above glass as a basic composition, adding PbO 2.5% and BaO 2%, The weight ratio of MgO: PbO + BaO is about 1.5:
It is shown by comparing with the thermal expansion curve (b) of the crystallized glass obtained by similarly heat-treating the glass designated as No. 1. As is clear from the figure, the addition of PbO + BaO can significantly prevent the bending of the thermal expansion curve.

The TiO ₂ component is indispensable as a nucleating agent, but if the total amount is less than 2%, desired crystals cannot be formed, and if it exceeds 15%, the glass becomes unstable.

The B ₂ O ₃ component is effective in improving the meltability of glass, but if its amount exceeds 10%, it becomes difficult to form desired crystals.

_{La 2 O 3, Y 2 O} 3, Gd 2 O 3, Ta 2 O 5, Nb
_{Since the 2} O ₅ and WO ₃ components are effective in improving the hardness and chemical durability of the product, the total amount of one or more of these components can be contained up to 10%.

The ZrO ₂ , P ₂ O ₅ and SnO ₂ components can be used auxiliary as nucleating agents, but the total amount of one or more of these components is 5% and each component is 2.
If it exceeds 5%, 5% or 2%, the stability of the glass may be deteriorated or the product structure may be inhomogeneous.

The As ₂ O ₃ and / or Sb ₂ O ₃ component may be added as a fining agent during glass melting, but the total amount of one or two of these is preferably 2% or less.

Further, when one or more of the above metal oxides, fluorides of metal elements are contained, it is effective for adjusting crystallization and the like, but if the amount exceeds 5% as a total amount of F, the glass is In addition to being unstable, the desired product cannot be obtained.

The above components of the raw glass in the present invention are 9 in total.
It is preferably set to 0% or more, in addition to the above components, _MnO 2 in _a range that does not impair the desired properties, up to about 10% in _{total, Ni 2 O 3, Co 2} O 3, Fe 2 O 3 And colorants such as Cu ₂ O and GeO ₂ and Bi ₂ O ₃
Up to about 1% in total of Li ₂ O, Na ₂ O, K ₂
Components such as O and SO ₃ may be contained.

Next, the feature of the method for producing crystallized glass according to the second invention of the present application is that the raw glass having the above composition is melted, shaped, heated and heated, and then heat-treated for crystallization at a temperature of 1150 ° C. or lower. Is to do.

In carrying out the method for producing a crystallized glass of the present invention, heating and raising the low temperature region of each glass forming temperature at a rate of 2.5 ° C./min or more will further improve the denseness and homogeneity of the structure. It is preferable because an excellent product can be easily obtained.

Further, in the production method of the present invention, since it has been found that the polished surface is not substantially changed even if the raw glass is crystallized after precision polishing such as mirror polishing, When a polished crystallized glass product is required, it is preferably carried out at the stage of the raw glass, which has a small hardness and is advantageous for precision polishing work.

[Examples] Next, preferred examples of the present invention will be described.

Table 1 shows an example of the composition of the crystallized glass of the present invention (No. 1).
-19) and conventional _SiO 2 -Li ₂ O system, _SiO 2 -A
l ₂ O ₃ -ZnO system and _SiO 2 _-Al 2 _O 3 -Zn
Comparative composition examples (Nos. A to D) of O—TiO ₂ system were subjected to respective heat treatment conditions and the linear thermal expansion coefficient of the obtained product; α
It is shown together with the measurement results of x10 ^-7 / ° C (measurement temperature range; 50 to 600 ° C), Vickers hardness (Hv), and crystal grain size. Further, Table 2 shows the examples (No. 1 to 3) of the method for producing crystallized glass of the present invention and the same glass composition as those, and only the heat treatment conditions were changed, and the small heating rate was obtained in the low temperature range. For the reference examples (No. 1'to 3 ') when given, the glass compositions used, the respective heat treatment conditions, and the various properties of the obtained products are shown in comparison with each other in Table 1.

Table 3 shows changes in various properties of another example (No. 1 to 3) of the method for producing a crystallized glass of the present invention, using the same glass composition and changing only the heat treatment temperature. It is shown. The raw glass of the above embodiment of the present invention is
In each case, raw materials such as oxides, carbonates, nitrates and fluorides are mixed, and this is mixed with a conventional melting device to about 1350 to
It was obtained by melting at a temperature of 1500 ° C., homogenizing by stirring, shaping into a desired shape and cooling. Thereafter, the temperature is raised at a rate of 2.6 to 10 ° C./min, and the temperature is maintained at each of the indicated crystallization temperatures for 60 to 180 minutes to form crystal nuclei to generate fine crystals, thereby obtaining a desired crystallized glass. It was

As can be seen from Table-1, the crystallized glasses of Comparative Examples A, B and C show a bend in the thermal expansion curve because the main crystal is α-cristobalite, and the average crystal grain size is about 1 or less.
It is very large, 0 μ or more. Especially in Comparative Example A, the surface condition was poor and cracking was likely to occur. In addition, the glass of Comparative Example D has a very poor meltability, requires a high temperature of 1600 ° C. for melting, and the glass is unstable, and whitening occurs during molding.
Moreover, cracks were generated after crystallization, and various physical properties could not be measured. On the other hand, the crystallized glass of the example of the present invention,
In both cases, there is no bending in the expansion curve, and approximately 40 to 220 x 10
^It has a coefficient of thermal expansion in the range of ^-7 / ° C and has a Vickers hardness in the numerical range of about 720 to 1110 kgf / mm ² .
The crystal grain size is also as small as 0.02 to 0.4 μ, and the fineness is excellent.

In addition, as seen in Table 2, in the reference example heated at a small temperature rising rate of 2 ° C./min, the crystal grain size of 1 ′ was 0.
Although the fineness was as high as 02 to 0.03 μ, the Vickers hardness was smaller than the desired value and cracks occurred in 2 ′ and 3 ′, and various physical properties could not be measured. On the other hand, the crystallized glass according to the example of the method of the present invention which was rapidly heated at a temperature rising rate of 2.5 ° C./min or more, both the thermal expansion coefficient and the Vickers hardness were within the desired ranges, and the crystal grain size was Also has excellent fineness of 0.02-0.3μ.

Further, as seen in Table 3, in the method of the present invention, using the raw glass of the same composition, by changing the crystallization temperature in a predetermined range, while maintaining the desired various properties,
The thermal expansion coefficient can be greatly changed.

Further, with respect to Examples No. 12 and No. 14 in Table-1, the raw glass was sliced into a thin plate of 10.0 × 10.0 × 1.0 mm, precision-polished, and its surface roughness (Rma
x) is 185Å (No. 12) and 70Å (No. 14), and then subjected to the heat treatment described, the crystallized glass obtained has no change in shape and its surface roughness Is
It was confirmed that it was 200 Å and 90 Å, respectively, and there was no substantial change in the mirror surface state before and after the heat treatment.
Therefore, even if it is necessary to add mirror polishing work to improve the surface accuracy after crystallization, the labor is greatly reduced.

Each of the crystallized glasses according to the examples of the present invention has a good meltability of 1,500 ° C. or less when it is a raw glass and is excellent in productivity, and is substantially alkali-free and excellent in chemical durability. Moreover, it has a large thermal conductivity of about 2 to 4 kcal / mh ° C as a crystallized glass.

As described [Effect of the Invention] above, the crystallized glass of the present invention, _SiO 2 having a specific composition _{-Al 2 O 3 -ZnO-MgO-} PbO-T
Since it is obtained by heat-treating an iO ₂ glass,
It has a desired hardness and a wide range of coefficient of thermal expansion, and is excellent in the denseness and homogeneity of the structure, and exhibits an excellent thermal expansion curve with improved bending. Therefore, as a substrate material for various magnetic heads such as a thin film type, a substrate material for various ICs, a substrate material for a magnetic disk, a substrate material for a superconducting material such as a thin film, etc. Is particularly suitable. It can also be used as a mechanical material such as bearing balls and spinning guides, and as a building material such as tiles.

Further, the method for producing a crystallized glass of the present invention uses the glass of the above system and crystallizes the glass at a predetermined relatively low temperature, so that a product further excellent in the above various characteristics can be obtained with a higher yield. it can.

[Brief description of drawings]

FIG. 1 shows a thermal expansion curve (a) of a conventional crystallized glass,
It is a comparison figure with the thermal expansion curve (b) of the crystallized glass of the Example of this invention.

Claims (4)

[Claims] 1. By weight percent, SiO ₂ 30-65%, Al ₂
O ₃ 5-25%, ZnO 10.5-40%, MgO
3.5-20%, PbO 0.5-10%, CaO + S
rO + BaO 0-15%, TiO ₂ 2-15%, B _{2
O 3 0~10%, La 2 O} 3 + Y 2 O 3 + Gd 2 O 3 +
_{Ta 2 O 5 + Nb 2 O} 5 + WO 3 0~10%, ZrO 2
_{+ P 2 O 5 + SnO 2} 0~5%, provided that _ZrO 2 0 to
_{2.5%, P 2 O 5 0~5} %, SnO 2 0~2%, As
₂ O ₃ + Sb ₂ O ₃ 0 to 2% and one or more kinds of the metal oxides of each of the above metal elements, obtained by heat treating a glass containing 0 to 5% as a total amount of F. And a glass having a coefficient of thermal expansion in the range of 40 to 220 × 10 ⁻⁷ / ° C. 2. SiO ₂ 30-65% by weight, Al ₂
O ₃ 5-25%, ZnO 10.5-40%, MgO
3.5-20%, PbO 0.5-10%, CaO + S
rO + BaO 0-15%, TiO ₂ 2-15%, B _{2
O 3 0~10%, La 2 O} 3 + Y 2 O 3 + Gd 2 O 3 +
_{Ta 2 O 5 + Nb 2 O} 5 + WO 3 0~10%, ZrO 2
_{+ P 2 O 5 + SnO 2} 0~5%, provided that _ZrO 2 0 to
_{2.5%, P 2 O 5 0~5} %, SnO 2 0~2%, As
A glass containing 0 to 2% of ₂ O ₃ + Sb ₂ O _{3 and} 0 to 5% of the total amount of F, which is a fluoride of one or more metal elements of the above metal oxides, is melted and molded. After that, the method for producing crystallized glass is characterized in that the temperature is raised by heating and then heat treatment for crystallization is performed at a temperature of 1150 ° C. or lower. 3. The low temperature range of glass nucleation temperature is 2.5 ° C. /
The method for producing crystallized glass according to claim 2, wherein the temperature is increased by heating at a rate of not less than minutes. 4. The method for producing crystallized glass according to claim 2 or 3, wherein the forming step includes a precision polishing process step.