JP3421284B2 - Negatively heat-expandable glass ceramics and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention can be used in a wide range of applications such as energy-related fields, information and communication fields, and electronics fields, and particularly in the field of optical communication, a temperature compensating member for a device including an optical fiber such as an optical fiber refractive index diffraction grating or a connector. The present invention relates to a negative thermal expansion glass ceramics and a method for producing the same.

[0002]

2. Description of the Related Art In recent years, optical technology has been applied not only in the field of communication systems, but also in a wide range of fields such as precision processing technology, medical technology, home appliances and industrial electronics. In such an optical technique, an optical fiber is used to perform light emission, light collection, light transmission, and branching. By the way, various devices using optical fiber are
It is necessary to have a structure that does not impair the characteristics of the optical fiber itself. In other words, it is necessary to combine materials having a desired coefficient of thermal expansion in order to prevent the optical properties from changing due to expansion and contraction of the optical fiber due to temperature changes. For example, the coefficient of thermal expansion is negative. Devices using materials have also been proposed.

For example, Japanese Unexamined Patent Publication No. 10-90555 discloses a single-core optical connector in which a flange portion of a ferrule made of zirconia or stainless steel having a positive coefficient of thermal expansion has a negative coefficient of thermal expansion. It is disclosed to use a liquid crystal polymer. Also, WO97
/ 14983 discloses an optical fiber diffraction grating whose periphery is coated with a liquid crystal polymer having a negative coefficient of thermal expansion in order to prevent expansion and contraction of the optical fiber having a positive coefficient of thermal expansion due to temperature change. . The thermal expansion coefficient of the liquid crystal polymer (polyester amide) disclosed herein is
It is -1.8 * 10 < ^-5 > / [deg.] C. to -7.2 * 10 < ^-6 > / [deg.] C.
Further, in Japanese Patent Laid-Open No. 10-96827, an optical fiber having a refractive index grating is attached to a support member made of a Zr-tungstate or Hf-tungstate-based composition having a negative coefficient of thermal expansion. Packages are disclosed. Specifically, -4.7-
A ZrW ₂ O ₈ powder having a coefficient of thermal expansion of 9.4 × 10 ⁻⁶ / ° C. forms a sintered body of −12.4 × 10 ⁻⁶ / ° C.

In addition, in various devices and equipment used in the fields of energy and information, etc., devices constituting these devices and equipment in order to prevent distortion and internal stress caused by temperature difference. Materials that can adjust the coefficient of thermal expansion of precision components to appropriate values and that also satisfy dimensional accuracy, dimensional stability, strength, thermal stability, and the like are required. Furthermore, by mixing with organic substances or inorganic substances used in the above various devices, precision parts, etc., such as adhesives and sealing materials, the thermal expansion coefficient of these substances can be adjusted to an appropriate value. Materials that can satisfy dimensional accuracy, dimensional stability, strength, thermal stability, etc. are required. As such a material, ceramics, glass ceramics, glass, metal and the like are used because of their high heat resistance and small coefficient of thermal expansion. However, these materials have a positive coefficient of thermal expansion, that is, have the property of expanding when the temperature rises, and are not necessarily optimum materials.

Therefore, various devices such as those listed above are used.
Used in materials such as chairs and various devices mentioned above
The materials to be mixed with the substances
Other materials used for
Negative coefficient of thermal expansion that cancels the positive coefficient of thermal expansion
Number, that is, a material that has the property of shrinking when the temperature rises
Is desired. Material with such a negative coefficient of thermal expansion
Is generally a β-eucryptite crystal, or
Is Li containing the crystal₂O-Al₂O₃-SiO₂System ceramic
Cous, Li₂O-Al₂O₃-SiO₂Glass ceramic
ZnO-Al₂O₃-SiO ₂Glass ceramic
, Lead titanate, hafnium titanate, tungstic acid
Inorganic substances such as zirconium and tantalum tungstate
It has been known.

For example, Japanese Patent Laid-Open No. 63-201034 discloses that volcanic glassy deposit powder contains Al ₂ in a specific range.
O ₃ and Li ₂ O powders are mixed, heated and melted, and then subjected to a treatment for removing strain, and further under a temperature within a specific range.
Crystallized glass (glass-ceramics) having a negative coefficient of thermal expansion by reheating for ~ 24 hours and then slowly cooling
A method of manufacturing is disclosed. In this method, the negative thermal expansion coefficient is −60 × as the crystallized glass having the largest absolute value by changing the conditions of the heat treatment time and the heat treatment temperature.
It has been obtained about 10 ^-7 / ° C.

[0007]

However, the materials having various negative coefficients of thermal expansion described in the above publications have various problems as described below. The above-mentioned Japanese Patent Laid-Open No.
-90555 and WO97 / 14983, the liquid crystal polymer used as the negative thermal expansion material is a crystalline resin, so that the crystal orientation is strong, and there is a problem such as warpage in an injection molded product. There is.
Another problem is that physical properties such as the coefficient of thermal expansion, bending strength, and elastic modulus also differ depending on the direction of liquid crystal molecules. In addition, ZrW ₂ O ₈ and HfW ₂ O ₈ used as temperature compensating members in the above-mentioned JP-A-10-96827 are 15
Since the phase transition occurs at around 7 ° C. and the thermal expansion curve is bent, it cannot be said that it is thermally stable in a wide temperature range.

Further, the crystallized glass disclosed in the above-mentioned Japanese Patent Laid-Open No. 63-201034 uses a volcanic glassy deposit as a raw material and is a main component necessary for precipitating a main crystal phase. ₂ and the content of each component other than Li ₂ O such as alkali metal oxides, alkaline earth oxides and transition metal oxides cannot be adjusted,
There are drawbacks that the composition cannot be changed, it is difficult to deposit a desired amount of a crystal phase in a predetermined amount, and it is not possible to produce a crystallized glass that is stable in terms of physical properties and quality. Furthermore, as seen in the examples of the above publications,
The manufacturing method is such that the mixed powder is melted to form a cullet, the cullet is crushed and melted again at 1600 ° C., the process is complicated, and the melting temperature of the glass is extremely high. There is a problem that manufacturing requires labor and cost.

Further, Japanese Patent Laid-Open No. 2-208256 discloses ZnO-Al ₂ O ₃ -SiO ₂ -based low thermal expansion ceramics whose main crystal phase is β-quartz solid solution and / or zinc petalite solid solution. However, even if this ceramic has the lowest coefficient of thermal expansion, it is -2.15 × 10 ^-6 / ° C (-21.
It is 5 × 10 ⁻⁷ / ° C.), and it cannot be said that it has a sufficiently low negative thermal expansion coefficient. Further, since this ceramic contains a large amount of ZnO component that easily sublimes at high temperature, it is described in the above publication that excessively long melting is not preferable when forming the parent glass (raw glass). As seen in the examples of the publication, the melting time is extremely short at 10 minutes. However, in such a short time, even if the temperature is high, the SiO ₂ and Al ₂ O ₃ components are not sufficiently melted and remain unmelted, so that a homogeneous parent glass cannot be obtained, and such a heterogeneous parent glass is not obtained. Even if glass is crystallized, homogeneous ceramics cannot be obtained. If the glass is melted, if it is melted for several hours as is usually done,
Although the unmelted residue can be eliminated, in that case, the ZnO component sublimes and the composition of the parent glass fluctuates, so that a stable and homogeneous ceramic cannot be obtained.
Further, the melting temperature of the above-mentioned example is as high as 1620 ° C., and it has the same problem as the manufacturing method disclosed in the above-mentioned JP-A-63-201034.

As described above, the conventional materials having a negative coefficient of thermal expansion have some problems, and therefore, they are not so well used in the energy-related field, the information field, the optical communication field and other various fields. The fact is that it is not used.

In view of the above situation, the object of the present invention is sufficiently large in a general temperature range of −40 ° C. to + 160 ° C. when used in the fields of energy-related fields, information fields, optical communication fields and the like. Provided is a negative thermal expansion glass ceramics which has a negative coefficient of thermal expansion of absolute value, can be stably produced at low cost in terms of composition and physical properties, and can be used as a temperature compensating member, and a manufacturing method thereof. To do.

[0012]

Means for Solving the Problems The inventors of the present invention have conducted various test studies in order to achieve the above object, and as a result, have selected Li ₂ O--Al ₂ O ₃ --SiO ₂ --BaO type glass having a specific composition range. It was found that a glass ceramic having no anisotropy and a large absolute value of a negative thermal expansion coefficient can be obtained by heat treatment and crystallization, and the present invention has been completed.

[0013] That is, in order to solve the above problems, the invention according to claim 1, in a temperature range of -40 ℃ ~ + 160 ℃, thermal expansion coefficient at -25~-100 × 10 ^-7 / ℃
Yes , the main crystalline phase is β-eucryptite solid solution (β-
Li ₂ O ・ Al ₂ O ₃ ・ 2SiO ₂ solid solution), β-Eucli
Putite (β-Li ₂ O ・ Al ₂ O ₃ ・ 2SiO ₂ ), β-
Quartz solid solution (β-SiO ₂ solid solution) and β-quartz (β
-SiO ₂ ) one or more selected from negative
A thermally expansive glass-ceramic having a mass% of Ba
It is characterized by containing 0.5 to 4% of O component .

The invention described in claim 2 is the same as claim 1
The negative thermal expansion glass-ceramics described in (1) above are characterized by containing , in mass%, SiO ₂ 40 to 65% Al ₂ O ₃ 25 to 45% Li ₂ O 5 to 15% .

According to a third aspect of the present invention, in the negative thermal expansion glass-ceramic according to the second aspect, the total crystal amount of the main crystal phase is 70 to 100% by mass. To do.

According to a fourth aspect of the present invention, in the negative thermal expansion glass-ceramic according to any one of the first, _{second and third} aspects, the mass% is SiO ₂ 40 to 65% Al ₂ O ₃ 25 to 45. % Li ₂ O 5 to 15% B ₂ O ₃ 0 to 3% BaO 0.5 to 4% MgO 0 to 2% CaO 0 to 3% ZnO 0 to 6% P ₂ O 5 0 to 4% ZrO ₂ 0 to 4 % TiO ₂ 0 to 4% As ₂ O ₃ + Sb ₂ O ₃ 0 to 2% of each of these components, and PbO and Na ₂
It is characterized in that it is obtained by heat-treating a raw glass that does not substantially contain O and K ₂ O.

The invention according to claim 5 is the invention as defined in claims 1, 2 and
In the negative thermal expansion glass ceramic according to any one of 3 or 4, in _{mass%, SiO 2 40~65% Al 2} O 3 25~45% Li 2 O 5~15% B 2 O 3 0~3% BaO 0.5 to 4% MgO 0 to 2% CaO 0 to 3% ZnO 0 to 6% P ₂ O ₅ 0 to 4% ZrO ₂ 0 to 4% TiO ₂ 0 to 4% As ₂ O ₃ + Sb ₂ O ₃ Each of these components is contained in a proportion of 0 to 2%, and PbO and Na ₂
It is characterized in that it is obtained by melting a raw glass substantially free of O and K ₂ O, melting it, quenching it, making it into a powder, shaping it, and then crystallizing it by firing.

The invention described in claim 6 is the same as in claims 1, 2 and
In the negative thermal expansion glass ceramic according to any one of 3 or 4, in _{mass%, SiO 2 40~65% Al 2} O 3 25~45% Li 2 O 5~15% B 2 O 3 0~3% BaO 0.5 to 4% MgO 0 to 2% CaO 0 to 3% ZnO 0 to 6% P ₂ O ₅ 0 to 4% ZrO ₂ 0 to 4% TiO ₂ 0 to 4% As ₂ O ₃ + Sb ₂ O ₃ Each of these components is contained in a proportion of 0 to 2%, and PbO and Na ₂
It is characterized by being obtained by melting a raw glass containing substantially no O and K ₂ O, shaping it, gradually cooling it if necessary, and then crystallizing it by heating.

The negative thermal expansion glass-ceramic according to any one of claims 1 to 6 has a large negative absolute thermal expansion coefficient. In addition, the negative thermal expansion glass-ceramic according to any one of claims 1 to 6 of the present invention has a crystallized region but does not have a specific orientation as a whole material, As described in No. 9, it is a material having almost no anisotropy.

Therefore, the negative thermal expansion glass-ceramics according to any one of claims 1 to 6 or 9 are used as a temperature compensating member in combination with a material having a positive coefficient of thermal expansion, as in the invention according to claim 10. It In particular, claim 11
The invention is preferably used in a device for fixing an optical fiber, as in the invention described in 1. According to the tenth and eleventh aspects of the present invention, by using the negative thermal expansion glass-ceramics of the present invention in combination with a material having a positive coefficient of thermal expansion as a temperature compensation member, a temperature change of a device or the like can be achieved. It is possible to prevent the adverse effect caused by. Here, examples of the device for fixing the optical fiber include an optical fiber refractive index diffraction grating and an optical connector used in the optical communication field.

The invention according to claim 7 is, in mass%, SiO ₂ 40 to 65% Al ₂ O ₃ 25 to 45% Li ₂ O 5 to 15% B ₂ O ₃ 0 to 3% BaO 0.5 to 4% MgO 0-2% CaO 0-3% ZnO 0-6% P ₂ O ₅ 0-4% ZrO ₂ 0-4% TiO ₂ 0-4% As ₂ O ₃ + Sb ₂ O ₃ 0-2% It contains each of these components in a proportion and contains PbO and Na ₂
A raw glass that does not substantially contain O and K ₂ O is melted, rapidly cooled, powdered, and then molded,
It is a method for producing a negative thermal expansion glass-ceramic, which comprises firing at a temperature of 350 ° C. for crystallization.

The invention according to claim 8 is, in mass%, SiO ₂ 40 to 65% Al ₂ O ₃ 25 to 45% Li ₂ O 5 to 15% B ₂ O ₃ 0 to 3% BaO 0.5 to 4% MgO 0-2% CaO 0-3% ZnO 0-6% P ₂ O ₅ 0-4% ZrO ₂ 0-4% TiO ₂ 0-4% As ₂ O ₃ + Sb ₂ O ₃ 0-2% It contains each of these components in a proportion and contains PbO and Na ₂
A raw glass containing substantially no O and K ₂ O is melted, shaped, and gradually cooled as necessary, and then 620 to 800
A method for producing a negative thermal expansion glass-ceramic, which comprises nucleating at a temperature of ° C and then crystallizing at a temperature of 700 to 950 ° C.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION The negative thermal expansion glass ceramics of the present invention will be described in detail below. In the present invention, the glass-ceramic is a material obtained by precipitating a crystal phase in the glass phase by heat-treating the glass, and not only the material consisting of the glass phase and the crystal phase, but the entire glass phase is crystallized. Also included are materials that have undergone a phase transition to a phase, that is, those in which the amount of crystals in the material is 100% by mass.

The main crystal phase of the negative thermal expansion glass-ceramics of the present invention is a β-eucryptite solid solution (β-Li _{2
O · Al 2 O 3 · 2SiO} 2 solid solution), beta-eucryptite _{(β-Li 2 O · Al} 2 O 3 · 2SiO 2), β- quartz solid solution (β-SiO ₂ solid solution) and beta-quartz (beta -S
One or two or more selected from iO ₂ ). Here, the solid solution means β-eucryptite, or β-eucryptite.
Quartz is a crystal in which some of the crystals are substituted or atoms penetrate between the crystals.

These main crystal phases are important factors contributing to the coefficient of thermal expansion of the negative thermal expansion glass-ceramics of the present invention. By heat-treating the raw glass under predetermined conditions, in the glass phase having a positive coefficient of thermal expansion, the main crystalline phase having a negative coefficient of thermal expansion is precipitated, or all the glass phases are the main crystalline phase. Phase transition to the containing crystal phase,
The coefficient of thermal expansion of the glass ceramic as a whole can be controlled within a desired numerical range. The types and precipitation amounts of these main crystal phases are determined by the content ratios of Li ₂ O, Al ₂ O ₃ and SiO _{2 in} the specific composition range, and the firing crystallization temperature or crystallization temperature described later. In order to obtain the target thermal expansion coefficient of the present invention, the total crystal amount of the main crystalline phase is preferably in the range of 70 to 100% by mass%, and when it is less than 70%, the thermal expansion coefficient is the main value. It may be higher than the target range of the invention.

The oxide composition of the negative thermal expansion glass-ceramics of the present invention is represented by the oxide composition of the original glass. The reason why the composition range of the original glass is limited as described above will be described below.

The SiO ₂ , Li ₂ O and Al ₂ O ₃ components are
It is an important component as a constituent element of the main crystal phase of β-eucryptite solid solution, β-eucryptite, β-quartz solid solution and β-quartz. The SiO ₂ component is the main component of the main crystal having a negative coefficient of thermal expansion, but its amount is 4
When it is less than 0%, it becomes difficult to precipitate the desired main crystal phase sufficiently, and when it exceeds 65%, it becomes difficult to clarify the glass melt and crystal phases other than the desired main crystal phase precipitate. , The preferred range of the amount of SiO ₂ component is 40 to 65%.

If the Al ₂ O ₃ component content is less than 25%, it will be difficult to melt the glass and the homogeneity of the raw glass will deteriorate, and it will be difficult to generate the desired main crystal phase in the required amount. On the other hand, if it exceeds 45%, the melting point becomes too high, and it becomes difficult to clarify the glass by melting. Therefore, the desirable range of the amount of the Al ₂ O ₃ component is 25 to 45%.

If the Li ₂ O content is less than 5%, the required amount of the desired main crystal phase cannot be obtained. On the other hand, if it exceeds 15%, vitrification tends to be difficult, and the strength of the glass ceramics after heat treatment decreases, so the preferable range is 5 to 15%.

The B ₂ O ₃ component can be optionally added for the purpose of improving the melting property of the raw glass, but it is a component forming the glass phase portion of the negative thermal expansion glass ceramics of the present invention, and its amount is 3%. If it exceeds, the production of the desired main crystal phase is hindered, and the coefficient of thermal expansion becomes larger than the target value.

Each of the components BaO, MgO, ZnO and CaO is a β-eucryptite solid solution (β-Li ₂ O.
Al ₂ O ₃ .2SiO ₂ solid solution) and β-quartz solid solution (β-SiO ₂ solid solution) are important constituents, but the amount of each of these components is 4%, 2%,
If it exceeds 6% and 3%, the coefficient of thermal expansion becomes large, and it becomes difficult to obtain the target coefficient of thermal expansion. Of the above components, the BaO component prevents the platinum in the crucible from alloying with other metal elements in the raw glass during melting of the raw glass and maintains the devitrification resistance of the raw glass. effective.
However, if the amount is less than 0.5%, this effect is not sufficiently obtained and the devitrification resistance of the raw glass deteriorates, so 0.5% or more is preferably contained.

Each of the components P ₂ O ₅ , ZrO ₂ and TiO ₂ acts as a crystal nucleating agent, but if the amount of each of these components exceeds 4%, it is difficult to clarify the melting of the raw glass. And unmelted matter may be generated. Therefore, it is particularly preferable that the TiO ₂ component is up to 3.5% and the ZrO ₂ component is up to 2% among the above components.

The As ₂ O ₃ and Sb ₂ O ₃ components can be added as fining agents during glass melting in order to obtain a homogeneous product, but a total amount of these components of up to 2% is sufficient. . In addition to the above components, other components such as a coloring component can be added as long as the desired properties of the glass ceramics of the present invention are not impaired.

It should be noted that the PbO component is a component which requires cost for environmental measures, and when the Na ₂ O and K ₂ O components are contained, these ions will be generated in the post-process such as film formation and cleaning. Since the physical properties of the negative thermal expansion glass-ceramics of the present invention change due to diffusion, PbO, Na ₂ O
And it is preferable that the K ₂ O component is not substantially contained.

The glass ceramics of the present invention having the above composition is preferably produced by the following two methods. First, in any of the methods, glass raw materials such as oxides, carbonates, hydroxides, and nitrates are weighed and mixed so as to have the above-described composition, put into a crucible, and the like.
It melts at 0 to 1500 ° C. for about 6 to 8 hours with stirring to obtain a raw glass in a clear state. Next, crystallization is performed by the following two methods.

First, in the first method, the raw glass in a molten state obtained above is quenched by a roll quenching method, an underwater quenching method, or the like. Next, the rapidly cooled glass is made into powder by a known pulverizing method such as a wet method or a dry method using a known pulverizing device such as a ball mill, a planetary ball mill, or a roller mill. The maximum particle size of glass powder is 100 μm or less,
The average particle size is preferably 10 μm or less, and the average particle size is 5 μm.
The following is particularly desirable. Maximum particle size is 100 μm
If it exceeds, the temperature required for firing and crystallization, which will be described later, becomes high, and the homogeneity and denseness of the obtained glass ceramics deteriorate.

Next, the glass powder thus obtained is molded into a desired shape by a known molding method such as press molding. At the time of this molding, polyvinyl alcohol, stearic acid, polyethylene glycol or the like can be added as an organic binder. In the case of molding into a particularly large block, it is desirable to mix an organic binder, and for example, 5 to 15% of an aqueous organic binder solution such as polyvinyl alcohol having a concentration of about 1 to 5% is added to 100% by mass of powder. preferable.

After the above-mentioned molding, a treatment for crystallization by firing is performed. The molded product is heated to 1200 to 135
Baking is performed by maintaining the temperature at 0 ° C. for about 2 to 10 hours. As a result, the desired main crystal phase is precipitated. After firing and crystallization, crystals having a negative coefficient of thermal expansion are deposited, so cracking occurs when rapidly cooled. Therefore, 50 ℃ / hr
It is desirable to gradually cool at the following rates. When firing and crystallization are performed here, it is not necessary to maintain the nucleation temperature, unlike the second method described later.

According to the first method described above, a negative coefficient of thermal expansion having a very large absolute value can be easily obtained. Moreover, since a molded product is produced from powder, a large product can be manufactured.

Next, the second method will be described. As described above, the raw glass is melted, cast into a mold or the like to be molded, and then gradually cooled as necessary for removing the strain of the molded glass. Next, crystallization processing is performed. First, 620-800
Hold at a temperature of ℃ to promote nucleation. This nucleation temperature is 6
Even if the temperature is lower than 20 ° C or higher than 800 ° C, crystal nuclei do not form. After nucleation, it is crystallized at a temperature of 700 to 950 ° C. If the crystallization temperature is lower than 700 ° C, a sufficient amount of the main crystal phase does not grow, and if it is higher than 950 ° C, the raw glass is melted and crystals having a large coefficient of thermal expansion such as β-spodumene are precipitated, which is desirable. Absent.
After crystallization, as described in the first method, 50 ° C. /
It is desirable to gradually cool at a rate not higher than hr.

The second method does not require the steps of crushing the raw glass and molding the powder, as compared with the first method of molding and firing the powder, so that the cost and time required for the production can be reduced. In addition, since the molded body does not contain pores, it is possible to obtain a glass ceramic of higher strength.

[0042]

EXAMPLES Examples of the negative thermal expansion glass ceramics of the present invention will be described below. The present invention is not limited to these examples.

Tables 1 and 2 show the glass ceramics of Example No. 1 of the present invention. 1-No. 7, the composition ratio, the firing crystallization temperature and the holding time, or the nucleation temperature,
The crystallization temperature and the holding time are shown. Example N
o. 1-No. The glass ceramic of No. 7 was manufactured as follows. First, glass raw materials such as oxides, carbonates, hydroxides, and nitrates are weighed and mixed so as to have the compositions shown in Tables 1 and 2, put into a platinum crucible, and this is put into a 1400 to 1400 using an ordinary melting apparatus. The mixture was melted and stirred at a temperature of 1550 ° C. for 6 to 8 hours.

After this, Example No. 1, No. 2 and No. Regarding No. 3, the raw glass in a molten state was dropped into water to be rapidly cooled. Next, the obtained glass molded body was pulverized by an alumina ball mill so that the average particle diameter was about 5 μm. Next, an organic binder was added and the mixture was molded by a uniaxial press. After that, the obtained molded body is put into a firing furnace, heated and heated, held at the firing crystallization temperature shown in Table 1 for a predetermined time and fired to be crystallized.
Glass ceramics were obtained by slow cooling at a rate of not more than ° C / hr.

In addition, in Example No. 4, No. 5, No.
6 and No. 6 As for No. 7, the molten raw glass was cast into a mold, molded, and then gradually cooled to obtain a glass molded body. Then, the glass molded body was put into a firing furnace as it was without being crushed, heated and heated, and kept at the nucleation temperature shown in Table 2 for a predetermined time to form crystal nuclei. Subsequently, the temperature was raised by heating, the temperature was kept at the crystallization temperature shown in Table 2 for a predetermined time for crystallization, and then the glass was gradually cooled at a rate of 50 ° C./hr or less to obtain glass ceramics.

A sample having a diameter of 5 mm and a length of 20 mm was cut out from the glass ceramics of the respective examples obtained as described above, and a temperature range of −40 ° C. to + 160 ° C. was measured by a TAS200 thermomechanical analyzer manufactured by Rigaku Corporation. The coefficient of thermal expansion was measured. Further, the total crystal amount of the main crystal phase of these glass ceramics was calculated from the peak area by the powder X-ray diffraction method. The results are shown in Tables 1 and 2.

Regarding the conventional glass ceramics, Comparative Example No. 1-No. 3 as Table 1 and Table 2
Similarly, shown in Table 3. Comparative Example No. 1 and No. Two
The glass ceramics of Example No. 4 to No. Comparative Example No. 7 was manufactured by the same method as in Example 7. The glass ceramics of No. 3 are those of Example No. 1-No. It was produced in the same manner as in 3. Further, the thermal expansion coefficient and the total crystal amount of the main crystal phase of the glass ceramics of each comparative example were measured in the same manner as above, and the results are shown in Table 3.

[0048]

[Table 1]

[0049]

[Table 2]

[0050]

[Table 3]

As can be seen from Tables 1 and 2, the glass ceramics of the examples according to the present invention have a coefficient of thermal expansion of −.
It shows a negative value of 26 to −96 × 10 ⁻⁷ / ° C., which is a very large absolute value. As a result of X-ray diffraction, the main crystal phase of these glass ceramics was found to be Example No. 1 and No.
In 7, β-eucryptite (β-Li ₂ O.Al ₂ O ₃
.2SiO ₂ ), Example No. 2, No. 3 and N
o. In No. 4, β-eucryptite solid solution (β-Li ₂ O
.Al ₂ O ₃ .2SiO ₂ solid solution), Example No. 5 and No. 6 was a β-quartz solid solution (β-SiO ₂ solid solution).

On the other hand, as a result of X-ray diffraction, Comparative Example N
o. 1, No. 2 and No. In No. 3, a β-quartz solid solution was precipitated and had a negative coefficient of thermal expansion as shown in Table 3, but a negative coefficient having a large absolute value could not be obtained.

Example No. The glass ceramics obtained in No. 4 was cut and polished to obtain a temperature compensating member having a length of 30.
A flat plate 1 having a size of mm × width 15 mm × thickness 2 mm and a cover plate 2 having the same dimensions were manufactured. A groove for setting an optical fiber was cut on the upper surface of the flat plate 1 with a diamond blade. Next, a silica-based optical fiber 4 having a refraction index diffraction grating 3 having a length of 10 mm is fitted into the groove, and at this time, the refraction index diffraction grating 3 is set so as to be located at the center of the flat plate 1. did. Next, while the cover plate 2 is covered on the optical fiber 4 and the refractive index diffraction grating 3, the flat plate 1 is coated with an adhesive.
1 and the cover plate 2 are pasted and combined to form
The assembly 5 shown in was produced. For this bonding, a conventionally known adhesive such as a thermosetting resin such as epoxy can be used, and a thermosetting epoxy adhesive was used in this example. In addition, Comparative Example No. Figure 1 using the glass ceramics of No. 1
An assembly similar to that was made (not shown).

The assembly 5 of FIG. The reflection wavelength obtained from the refractive index diffraction grating of each assembly of 1 is -4
The measurement was performed while changing the temperature between 0 ° C and + 100 ° C, and the results were compared. As a result, the assembly 5 using the glass-ceramics according to the present invention was compared with Comparative Example No. Compared with the assembly using the glass ceramic of No. 1, the temperature dependence of the reflection wavelength emitted from the refractive index diffraction grating was significantly reduced, and a stable reflection wavelength was obtained in the above temperature range.

Example No. FIG. 2 shows an SEM photograph (scanning electron microscope photograph) taken after mirror-polishing the surface of the glass ceramic of No. 2 and further etching with hydrofluoric acid. As seen in FIG. 2, the crystal grains precipitated in this glass ceramic have three-dimensional dispersion without orientation. Therefore, it is considered that the glass ceramic of Example 2 has almost no anisotropy inside.

[0056]

As described above, the negative thermal expansion glass-ceramic of the present invention has a coefficient of thermal expansion of −25 to −100 × 10 ⁻⁷ / in the temperature range of −40 ° C. to + 160 ° C.
C. and has a negative coefficient of thermal expansion with a very large absolute value. Therefore, in optical fiber related devices such as optical fiber refractive index diffraction gratings and optical fiber connectors in the field of optical communication, by using in combination with a material having a positive coefficient of thermal expansion, it is possible to prevent the effects of temperature changes as much as possible. It is possible to function as a temperature compensation member. In addition, since it does not have anisotropy as a material, it does not cause problems such as molding defects and dispersion of physical properties due to anisotropy. Can be suitably used for the device.

Further, by utilizing the negative thermal expansion property, it can be used as a bulk material in a wide range of applications such as the energy-related field, the information communication field and the electronics field.
The negative thermal expansion glass-ceramics of the present invention have a particle size of 100 μm or less, preferably 5 or less by a known crushing device such as a ball mill, a vibration mill, a roller mill, a jet mill.
By pulverizing to 0 μm or less and mixing with organic substances and inorganic substances used in each of the above fields, the thermal expansion coefficient of these substances is reduced, and the filler (filler) for reducing thermal expansion, which is excellent in dimensional stability. Can be used as
These organic substances and inorganic substances are not particularly limited, and examples thereof include phenol resin, epoxy resin, polyamide resin, polycarbonate resin and the like, low melting point glass, etc., and also have a wide range of uses such as general industrial use and construction. Targeted is possible.

Further, the negative thermal expansion glass-ceramic of the present invention can be produced at a low cost because it can be produced by melting the raw glass at a relatively low temperature as compared with the prior art.
Moreover, in addition to being composed of components whose composition ratio can be easily controlled,
Since no unstable components are contained in the composition, stable production can be achieved in terms of composition and physical properties.

[Brief description of drawings]

FIG. 1 is a side sectional view of an assembly using a glass-ceramic according to the present invention as a temperature compensation member.

FIG. 2 is an SEM photograph (scanning electron microscope photograph) showing the surface of the glass ceramics according to the present invention.

[Explanation of symbols]

1 flat plate 2 cover plate 3 Refractive index diffraction grating 4 optical fiber 5 assembly

─────────────────────────────────────────────────── ─── Continuation of front page (31) Priority claim number Japanese Patent Application No. 11-287138 (32) Priority date October 7, 1999 (October 7, 1999) (33) Priority claim country Japan (JP) (56) References JP-A-63-201034 (JP, A) JP-A-61-242931 (JP, A) JP-A-2000-266943 (JP, A) US Pat. No. 4507392 (US, A) Jiin-Jyh Shuyu et. al. , Sintering, Crystalization, and Properties of B203 / P205-Doped Li20.Al203.4Si02 Glass-Ceramics, Journal of the America No. 78, August 7, 1995. Soc. 8, p. 2161-2167 E. G. Wolff, Thermal Expansion in Metal / Lithia-Alumina-Silica (LAS) Composites, International J. of Journal of Thermophysics, March 1988, Vol. 2, p. 221-232 Gerd Muller et al. , Glass-ceramics based on phases with NZP-typr structure, Glatech. Ber. , September 1994, Vol. 67, No. 9, p. 255-259 Yukiko Hori et al., C-3-46 Temperature compensation package for fiber grating, Proc. Of IEICE General Conference 1997, Electronics 1, March 6, 1997, p. 231 (58) Fields investigated (Int.Cl. ⁷ , DB name) C03C 1/00-14/00 G02B 6/00-6/54 WPI JOIS

Claims (11)

(57) [Claims] 1. A temperature range of -40 ℃ ~ + 160 ℃, thermal expansion coefficient of -25~-100 × 10 ^-7 / ℃ der
The main crystalline phase is β-eucryptite solid solution (β-Li _{2
O · Al 2 O 3 · 2SiO} 2 solid solution), beta-Yukuriputa
(Β-Li ₂ O ・ Al ₂ O ₃ ・ 2SiO ₂ ), β-quartz
Solid solution (β-SiO ₂ solid solution) and β-quartz (β-S
negative thermal expansion of one or more selected from iO ₂ ).
Tough glass-ceramics with BaO composition in mass%
A negative thermal expansion glass-ceramic containing 0.5 to 4% of a component. 2. The negative thermal expansion glass-ceramic according to claim 1, characterized in that it contains, by mass%, SiO ₂ 40 to 65% Al ₂ O ₃ 25 to 45% Li ₂ O 5 to 15%. . 3. The total crystal amount of the main crystal phase is% by mass.
And 70 to 100%, The negative thermal expansion glass-ceramics according to claim 2. In 4. _{mass%, SiO 2 40~65% Al 2} O 3 25~45% Li 2 O 5~15% B 2 O 3 0~3% BaO 0.5~4% MgO 0~2% CaO 0 to 3% ZnO 0 to 6% P ₂ O ₅ 0 to 4% ZrO ₂ 0 to 4% TiO ₂ 0 to 4% As ₂ O ₃ + Sb ₂ O ₃ 0 to 2% And PbO, Na <sub>2
2. A</sub> raw glass which does not substantially contain O and K ₂ O, which is obtained by heat-treating the raw glass.
The negative thermal expansion glass-ceramic according to any one of 2 and 3. 5. In mass%, SiO ₂ 40-65% Al ₂ O ₃ 25-45% Li ₂ O 5-15% B ₂ O ₃ 0-3% BaO 0.5-4% MgO 0-2% CaO 0 to 3% ZnO 0 to 6% P ₂ O ₅ 0 to 4% ZrO ₂ 0 to 4% TiO ₂ 0 to 4% As ₂ O ₃ + Sb ₂ O ₃ 0 to 2% And PbO, Na ₂
A raw glass substantially free of O and K ₂ O is obtained by melting, quenching, powdering, shaping, and then crystallization by firing. The negative thermal expansion glass-ceramic according to any one of 3 and 4. 6. _{mass%, SiO 2 40~65% Al 2} O 3 25~45% Li 2 O 5~15% B 2 O 3 0~3% BaO 0.5~4% MgO 0~2% CaO 0 to 3% ZnO 0 to 6% P ₂ O ₅ 0 to 4% ZrO ₂ 0 to 4% TiO ₂ 0 to 4% As ₂ O ₃ + Sb ₂ O ₃ 0 to 2% And PbO, Na ₂
4. A glass obtained by melting a raw glass containing substantially no O and K ₂ O, shaping it, slowly cooling it if necessary, and then crystallizing it by heating.
Alternatively, the negative thermal expansion glass-ceramic according to any one of 4 above. 7. In mass%, SiO ₂ 40-65% Al ₂ O ₃ 25-45% Li ₂ O 5-15% B ₂ O ₃ 0-3% BaO 0.5-4% MgO 0-2% CaO 0 to 3% ZnO 0 to 6% P ₂ O ₅ 0 to 4% ZrO ₂ 0 to 4% TiO ₂ 0 to 4% As ₂ O ₃ + Sb ₂ O ₃ 0 to 2% And PbO, Na ₂
A raw glass that does not substantially contain O and K ₂ O is melted, rapidly cooled, powdered, and then molded,
A method for producing a negative thermal expansion glass-ceramic, which comprises firing at a temperature of 350 ° C. for crystallization. 8. In mass%, SiO ₂ 40-65% Al ₂ O ₃ 25-45% Li ₂ O 5-15% B ₂ O ₃ 0-3% BaO 0.5-4% MgO 0-2% CaO 0 to 3% ZnO 0 to 6% P ₂ O ₅ 0 to 4% ZrO ₂ 0 to 4% TiO ₂ 0 to 4% As ₂ O ₃ + Sb ₂ O ₃ 0 to 2% And PbO, Na ₂
A raw glass containing substantially no O and K ₂ O is melted, shaped, and gradually cooled as necessary, and then 620 to 800
A method for producing a negative thermal expansion glass-ceramic, which comprises nucleating at a temperature of ° C and then crystallizing at a temperature of 700 to 950 ° C. 9. The negative thermal expansion glass-ceramic according to claim 1, which is a material having almost no anisotropy. 10. The negative thermal expansion property according to claim 1, which is used as a temperature compensation member in combination with a material having a positive coefficient of thermal expansion. Glass ceramics. 11. A device for fixing an optical fiber, wherein the device is used as a device.
The negative thermal expansion glass-ceramic according to 6, 9, or 10.