JP3120422B2 - Crystallized glass articles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to relates to a sintered crystallized glass article.

[0002]

2. Description of the Related Art Crystallized glass is a material that exhibits unique characteristics not found in amorphous glass due to various crystals precipitated in the glass. For example, when crystals such as β-quartz solid solution and β-spodumene solid solution are precipitated, crystallized glass having extremely low expansion or minus expansion can be obtained. Moreover, crystallized glass generally has higher mechanical strength than glass due to the presence of these crystals.

[0003] In recent years, crystallized glass having such excellent properties is precision-processed into a thin rod shape, a thin tube shape, a thin plate shape, or the like, and products requiring precise dimensional accuracy such as electronic parts and precision machine parts. Attempts have been made to apply it to the field.

[0004]

As a method for precisely processing glass, a forming method called a redraw forming method is known. In this method, a glass molded body preformed to have appropriate accuracy is stretch-formed while being heated to a temperature equal to or higher than the softening point of glass. Widely used as a manufacturing method.

However, in the case of conventional crystallized glass, it is difficult to perform redraw molding in the same manner as glass, for the following reasons. That is, the conventional crystallized glass has problems such as too high heat resistance, difficulty in stretching due to devitrification at the time of heating, and a large change in the physical properties due to a change in the amount of crystals due to heating. Because it is. Therefore, redraw molding of glass before being crystallized glass, so-called crystalline glass, has been studied. However, since this kind of glass is designed to be easily crystallized by heating, heating the crystalline glass for redraw molding inevitably causes devitrification, making it impossible to control not only dimensions but also physical properties .

Therefore, when obtaining a precision-processed product made of crystallized glass, the same machining as that of ceramics is required, and the cost is extremely high at present.

[0007] The present invention has been made in view of such circumstances, and an object thereof is to provide a crystallized glass article formed by manufacturing using a crystalline glass which can redraw forming.

[0008]

The devitrification region of the glass has a TTT (Time-Temperature-Transformatio) shown in FIG.
n) Can be represented by a diagram called a curve. TT-
The T curve is a graph in which temperature is plotted on the vertical axis and time is plotted on the horizontal axis, and the time until devitrification (crystal) occurs when glass is continuously heated at a certain temperature is plotted. The transparent region and the outside indicate a glass region.

In the case where the crystalline glass is formed by heating it, in order to prevent devitrification, it is only necessary to be able to form under temperature and time conditions other than the devitrification region in the drawing. Conducted various experiments and specified a crystallized glass composition that can be redrawn.

That is, the crystallized glass article of the present invention has a weight
SiO ₂ 60-75%, Al ₂ O ₃ 16-3 in percentage
0%, Li ₂ O 1.5 to 2.8%, K ₂ O 2.1 to 1
_{0%, TiO 2 1.3~5%,} ZrO 2 0~4%, T
iO ₂ + ZrO ₂ 2-9%, ZnO 1-10%, Mg
O 0-2.5%, CaO 0-4%, BaO 0-6
_{%, B 2 O 3 0~7%} , Na 2 O 0~4%, P 2 O 5
_{0~0.9%, As 2 O 3 0~3} %, Sb 2 O 3 0~3
%, Β-quartz solid solution or β-spodumene solid solution
Of crystalline glass that has the property of precipitating
The preform is stretched while being heated and then crystallized.
It is characterized by becoming.

[0011]

According to the present invention, there is provided a method for producing a crystallized glass article of the present invention.
Crystallizable glass is reheated at a temperature higher than the maximum temperature of the devitrification region.
Shows a draw moldable viscosity (10 ^4.5 to 10 ^6.5 poise)
It is something.

In the above crystalline glass, the glass composition is
State the reasons for the limitation.

[0013] SiO ₂ is the main constituent of glass
Together with the crystal constituents, the content is 60-75
%, Preferably 64-72%. 60% SiO ₂
If less than this, the viscosity of the glass becomes too low and redraw
Moldable temperature area overlaps with devitrification area, redraw molding
There is devitrification inside. On the other hand SiO ₂ than 75%
If the amount is too large, the melting property of the glass during melting deteriorates and uniform glass
Is difficult to obtain.

Al ₂ O ₃ is also a component constituting a crystal, and
Is 16 to 30%, preferably 17 to 24%.
You. If the content of Al ₂ O ₃ is less than 16%, the crystals are coarsened.
The properties of the resulting crystallized glass article are likely to deteriorate,
%, The devitrification region is undesirably enlarged.

Li ₂ O becomes a constituent component of the crystal,
1.5 to 2.8%, preferably 1.8 to 2.5%
It is. Uniform crystals if Li ₂ O is less than 1.5%
It is difficult to obtain fossilized glass.
As the glass expands, the viscosity of the glass tends to decrease,
-The moldable temperature region overlaps the devitrification region.

K ₂ O is an essential component for controlling the devitrification region.
Minutes, the content of which is 2.1 to 10%, preferably
2.5 to 7%. Loss occurs when K ₂ O is less than 2.1%
The maximum temperature of the devitrification zone rises because the permeability zone becomes too wide
You. On the other hand, if it exceeds 10%, the viscosity becomes too low.
In particular, crystallization becomes difficult.

TiO ₂ acts as a nucleating agent during crystallization
The content is 1.3 to 5%, preferably
Or 1.5 to 4.5%. TiO ₂ is less than 1.3%
If it is too small, a crystallized glass with a dense structure cannot be obtained,
If the amount is too large, a large amount of heterogeneous crystals will precipitate during crystallization and
It becomes difficult to obtain characteristics.

ZrO ₂ , like TiO ₂ , forms a nucleus during crystallization.
It is a component acting as a forming agent, and its content is from 0 to 4
%, Preferably 0.5 to 3%. 4% ZrO ₂
If the amount is too large, it becomes difficult to melt the glass.

The total amount of TiO ₂ and ZrO ₂ is 2 to 9%,
Preferably it is 3-6%. The combined amount of both is less than 2%
Otherwise, it will be difficult to obtain dense crystals, and if it exceeds 9%, glass
Tends to be uneven.

ZnO is a component that promotes melting of glass.
And its content is 1 to 10%, preferably 1.5 to 6%.
It is. If ZnO is less than 1%, the glass becomes uneven.
If more than 10%, a large amount of heterogeneous crystals will precipitate.
Go.

MgO is also a component that promotes melting of glass.
And its content is 0-2.5%, preferably 0-2%.
is there. If the content of MgO is more than 2.5%, the glass is easily devitrified.
Become .

[0022] CaO is also a component that promotes the melting of glass.
And its content is 0 to 4%, preferably 0 to 2%.
You. If the content of CaO is more than 4%, devitrification tends to occur.

BaO is also a component that promotes the melting of glass.
And its content is 0 to 6%, preferably 0 to 3%.
You. If BaO is more than 6%, devitrification tends to occur.

B ₂ O ₃ is also a component that promotes the melting of glass.
And its content is 0 to 7%, preferably 0 to 4%.
You. If B ₂ O ₃ is more than 7%, the glass becomes uneven.

Na ₂ O is also a component that promotes melting of glass.
And its content is 0 to 4%, preferably 0 to 2%.
You. If Na ₂ O is more than 4%, a large amount of heterogeneous crystals will precipitate.
Would.

P ₂ O ₅ has an action of making crystals fine, and
Is 0 to 0.9%, preferably 0 to 0.7%.
You. When P ₂ O ₅ is more than 0.9%, the devitrification area becomes wide.
Become.

As ₂ O ₃ and Sb ₂ O ₃ are used as fining agents
Respectively up to 3%, preferably up to 1.5% each.
Can be made.

In addition, the total amount does not exceed 5%.
SnO ₂ , PbO, Bi ₂ O ₃ etc. can be added within the range.
Wear.

The crystalline glass having the above composition is β-stone
Low solid content mainly composed of English solid solution or β-spodumene solid solution
It has the property of becoming an expanded crystallized glass. Note that
Precipitated crystals are not limited to these two types.
Unless the desired properties are impaired, heterogeneous crystals such as garnite will precipitate.
You can put it out.

Next, the crystallized glass article of the present invention will be described.
explain.

The crystallized glass article of the present invention is prepared by the following method.
It is manufactured.

First, the above-mentioned crystalline glass preform was used.
I mean.

Subsequently, the crystalline glass preform is heated and
While stretching. Heating temperature is the upper limit temperature of the devitrification area
At a temperature higher than a viscosity (10 ^4.5 to suitable redraw molding
10 ^6.5 poise).

After that, the redraw-formed crystalline glass
Crystallized glass article of the present invention by crystallizing
Becomes After redraw molding or crystallization,
Alternatively, processing such as cutting may be performed.

The crystallized glass article thus obtained
Is a β-quartz solid solution or β-spodumene as a main crystal.
Low expansion crystallized glass obtained by depositing a solid solution. Note that
The precipitated crystals are not limited to these two types.
If there is a different kind of crystal such as garnite
I can't.

[0036]

【Example】 Hereinafter, the present invention will be described based on examples.

Table 1 shows examples of the present invention (samples No. 1 to No. 1).
5) and Table 2 show comparative examples (sample No. 6), respectively.
I have.

[0038]

[Table 1]

[0039]

[Table 2]

Each sample was prepared as follows.

First, the ingredients were prepared so as to have the composition shown in the table.
The raw glass material is put into a glass melting furnace and heated at 1650 ° C.
After melting for 24 hours, the diameter of 50mm, length of 500mm
It was cast into a cylindrical shape. Next, the outer periphery is
Preform with 40mm diameter
And

The preformed body obtained in this manner is
Te, on possible temperature (redraw molding showing a 10 ^4.5 poise
Temperature) and the upper limit temperature of the devitrification area
In the example of No. 1 to 5 of the sample, 10 ^4.5 poi
Temperature is 1250-1380 ° C., and the upper limit of devitrification temperature is
A 1,160-1,220 ° C., the temperature showing a 10 ^4.5 poise
The degree was 50 to 220 ° C. higher than the upper devitrification temperature. on the other hand,
Sample No. which is a comparative example. 6, temperature indicating 10 ^4.5 poise
Temperature is 1230 ° C and the upper devitrification temperature is 1300 ° C.
70 ° C. High or than the temperature which indicates the permeability upper limit temperature is 10 ^4.5 poise
Was.

Subsequently, as shown in FIG.
The preform G is continuously fed from the top at a speed of 5 mm / min.
The lower end of the molded product that has
And sandwiched between them to form a thin rod with a diameter of 2.5 mm.
The film was stretched at a speed of 280 mm / min, and the moldability was evaluated. What
In the figure, g indicates a formed crystalline glass. Ma
The redraw molding was performed at the temperatures shown in the table. Evaluation of each sample
The results are shown in the table.

As is clear from the table, in the embodiment of the present invention,
No. Each sample of 1 to 5 shows moderate viscosity
Since no devitrification occurred, the moldability was good.
Was. On the other hand, in Comparative Example No. Using 6 samples,
What was redrawn at a temperature higher than the upper devitrification temperature,
No devitrification was observed, but viscosity during molding was too low
Shape could not be controlled. The 10 ^4.5 poise temperature of
When the glass is redrawn, the glass is significantly devitrified and rolled.
Cutting occurred during stretching.

Further, the sample No. 1 to
5 at 750 ° C. for 2 hours followed by 1100 ° C.
When reheated under the condition of 1 hour, the sample No. 1-4 are
The β-spodumene solid solution was prepared using Sample No. 5 is β-quartz solid
A crystallized glass having the solution as a main crystal was obtained.
The size and shape of each sample changed almost before and after reheating.
Not confirmed.

[0046] In addition, the temperature at which exhibits a viscosity of 10 ^4.5 poise
Was measured by a platinum ball lifting method. Devitrification upper limit temperature
After holding the sample in the temperature gradient furnace for a predetermined time, remove
And confirm the presence of precipitated crystals with an optical microscope.
I asked. The main crystal was investigated by X-ray diffraction.

[0047]

As described above, the crystallized glass material of the present invention
Products have high dimensional accuracy and can be supplied at low cost.
Suitable for electronic parts, precision machine parts and the like.

[Brief description of the drawings]

FIG. 1 is a graph showing a TTT curve.

FIG. 2 is an explanatory view showing redraw molding.

[Explanation of symbols]

 G Crystalline glass preform g Crystalline glass formed by redrawing 1 Annular electric furnace 2 Roller

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C03C 1/00-14/00 C03B 19/00-19/10 C03B 32/00-32/02

Claims (1)

(57) [Claims] 1. 60 to 75% of SiO _{2 by} weight,
_{Al 2 O 3 16~30%, Li} 2 O 1.5~2.8
_{%, K 2 O 2.1~10%,} TiO 2 1.3~5%,
ZrO ₂ 0-4%, TiO ₂ + ZrO ₂ 2-9%, Z
nO 1-10%, MgO 0-2.5%, CaO 0
~4%, BaO 0~6%, B 2 O 3 0~7%, Na 2
_{O 0~4%, P 2 O 5} 0~0.9%, As 2 O 3 0~
3%, consists _{Sb 2 O 3 0~3%, β} - after the quartz solid solution or β- spodumene solid solution preform crystallizable glass having a property of precipitating as a main crystal, were stretching with heating, crystal A crystallized glass article characterized by being made into a glass.