JP3180484B2 - Matrix glass for FRG - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fiber reinforced glass (FRG) matrix glass using a hot pressing method. The glass of the present invention has a high refractive index, and when used as a matrix glass of glass fibers having a high refractive index such as oxynitride glass, transparent FRG can be obtained.

[0002]

2. Description of the Related Art Conventional fiber reinforced glass (FR)
G) is mainly made of colored fiber such as carbon fiber made of Pyrex glass or lithium aluminosilicate having heat resistance.
It is a composite of crystallized glass such as (LAS) as a matrix, and does not take into account the transmittance of visible light.

[0003] Oxynitride glass has excellent physical properties, is useful as a reinforcing fiber, and is transparent and has high transmittance of visible light. However, oxynitride glass has a higher refractive index than ordinary oxide glass. When oxynitride glass is used as a reinforcing fiber and conventional Pyrex glass (refractive index: about 1.5) or the like is used as a matrix glass, both of them are used. FR that has a large difference in refractive index and high transparency especially in the visible region
You can't get G.

[0004] Further, since FRG is usually manufactured by a hot press method, matrix glass has a low softening point,
In addition, it is necessary that crystallization does not occur near the softening point.

For example, Izumaya (Report of Osaka Institute of Technology, v.
ol 311; July 1958) is B ₂ O ₃ —La ₂ O ₃ —Ba
High refractive index glass with a refractive index of 1.68 units is obtained in O system.
However, this glass cannot be said to have a sufficient refractive index for FRG using oxynitride glass fiber as a reinforcing fiber. In addition, this glass produces surface crystals, which is not preferable as a matrix glass for hot pressing.

An object of the present invention is to provide a high refractive index (1.65) as high as oxynitride glass used as a reinforcing fiber.
~ 1.72) and a low softening point (50
0 to 750 ° C.) and near the softening point (softening point +7).
(0 ° C. or less) is to provide a matrix glass for FRG which is hardly crystallized at 0 ° C. Another object of the present invention is to provide a matrix glass having low reactivity with glass fibers (reduction of oxides in the glass). Further, it is intended to reduce the use of expensive Nb ₂ O ₅ added for improving the refractive index.

[0007]

Means for Solving the Problems As a result of diligent studies on the above-mentioned problems, the present inventors have found that, with a predetermined glass composition, it has a refractive index equivalent to that of oxynitride glass, and uses a hot press method. The inventors have found that a matrix glass that can be applied is obtained, and have completed the present invention.

A first invention of the present invention is a matrix glass for FRG using oxynitride glass fiber as a reinforcing fiber, and its chemical composition is SiO _{2 in} mol%.
45-70%, Na ₂ O and / or Li ₂ O 5-2
5%, BaO 5 to 25%, Nb ₂ O ₅ 2 to 15% and K ₂ O 0 to 20%, having a refractive index of 1.70 to 1.72. To provide.

In an SiO ₂ —Na ₂ O—BaO-based glass, Nb ₂ O ₅ is kept at ₂ to 1 while maintaining SiO ₂ at 50 mol%.
5 mol% was introduced, and Na ₂ O was partially replaced with K ₂ O.
Such a matrix glass softens at 500 to 750 ° C and does not crystallize at a softening point + 30 ° C or lower. Thus Nb ₂ O ₅ the refractive index of the glass is increased by the addition of a softening point by substituted on a portion K ₂ O and Na ₂ O was reduced 20 to 40 ° C.. Further, when SiO ₂ is kept at 50% or more, crystallization does not occur at a softening point of + 70 ° C. or less.

Further, when Na ₂ O is replaced with Li ₂ O, the refractive index becomes larger, and the use of expensive Nb ₂ O ₅ can be reduced.

A second invention is a matrix glass for FRG using oxynitride glass fiber as a reinforcing fiber, and its chemical composition is SiO ₂ 45 to 7 in mol%.
0%, BaO 5-25%, Li ₂ O 5-25%, Y ₂ O
A ₃ 1% to 15% and Ta ₂ O ₅ 0.01~15%,
FR having a refractive index of 1.70 to 1.72
A matrix glass for G is provided.

[0012] Y increases the refractive index of the glass. Since this element has a valence of only +3, it has better reduction resistance than other elements. When Y is introduced into SiO ₂ —BaO—R ₂ O-based glass, alkali metal other than Li, such as Na and K, does not vitrify. Crystal addition during melting was suppressed by addition of Ta, and the refractive index also increased.

Further, a third invention is a matrix glass for FRG using oxynitride glass fiber as a reinforcing fiber, the chemical composition of which is SiO _{2 in} mole%.
_{30~45%, Na 2 O 20~30%} , BaO 0~5
_{%, K 2 O 0~10%,} TiO 2 25~35%, Al 2
O ₃ 0-5% and Cs ₂ O 0-5%, there is provided a FRG for the matrix glass, wherein the refractive index of 1.65 to 1.72.

Further, a fourth invention is a matrix glass for FRG using oxynitride glass fiber as a reinforcing fiber, wherein the chemical composition of the matrix glass is SiO
_{2 + B 2 O 3 40~90%} , BaO 5~55% and L
a ₂ O ₃ 5 to 55%, and is the total amount of these components total more than 80%, molar ratio of SiO ₂ and B ₂ O ₃ is 3.
FR characterized by being 0 / 3.4 to 3.0 / 4.3
A matrix glass for G is provided. In the glass having the composition of the present invention, a large amount of La having only a high valence (+3) could be introduced, and a glass having a high refractive index was obtained.

In particular, the glass of the fourth invention has high reduction resistance,
Does not react with oxynitride glass. Therefore, hot pressing can be performed in the air. Also, FRG
When used as a matrix glass, the glass has excellent light transmittance in the visible region, and has a refractive index substantially equal to that of oxynitride glass (refractive index N _d = 1.712). Furthermore, this glass is less likely to produce crystals, and is particularly suitable for FRG production by a hot press method. That is, in the conventional matrix glass, the cation of the metal oxide added to obtain a high refractive index is reduced by the oxynitride glass fiber, and the matrix glass is colored, and the light transmittance in the visible region is lost particularly. . Even if these conventional matrix glasses have high resistance to reduction, the atmosphere of the hot press is H
e + O ₂ had to be maintained.

In the fourth invention, SiO ₂ and B ₂ O ₃
When the composition ratio is 3.0: 3.4 to 4.3, that is, when the Si: B ratio is 3.0: 6.8 to 8.6, a transparent glass without crystals can be obtained. B ₂ O ₃ : SiO ₂ : BaO: La
In the O ₃ glass, the composition ratio of SiO ₂ and B ₂ O ₃ is set to 3.
When the ratio is maintained at 0: 3.4 to 4.3, the glass is stabilized, and a transparent glass can be obtained without crystallization. Regarding the refractive index of glass, B ₂ O ₃ + SiO ₂ is defined as X group, and Ba is defined as Ba.
Assuming that O and LaO ₃ are in the Y group, it can be easily adjusted by the relative ratio of X and Y and the ratio of BaO and LaO ₃ in the Y group.

In order to produce the matrix glass of the present invention, it is preferable to use a conventionally known melting method or the like. As a glass raw material, a metal oxide or the like is generally used. Alkali metals and alkaline earth metals are Li ₂ CO ₃ and Na ₂ C
Carbonates such as O ₃ , K ₂ CO ₃ , Cs ₂ CO ₃ and BaCO ₃ may be used. At high temperatures, CO ₂ is released from the carbonate to form an oxide. Melting of glass raw material powder in air is about 120
This is performed at 0 to 1300 ° C. in an appropriate device such as an electric furnace. The refractive index of the glass for matrix obtained in the first to fourth aspects of the present invention is 1.65 to 1.72, preferably 1.70 to 1.72.
It is.

[0018]

Next, the present invention will be described more specifically based on examples. In the examples,% means mol%.

Example 1 (First Invention) As a glass raw material, SiO ₂ : 29.71 g, Na ₂ C
O ₃ : 19.91 g, BaCO ₃ : 37.06 g, Nb
₂ O _{5: 28.91g} and K ₂ CO _3: 1.37g were weighed _{(SiO 2: 50%, Na} 2 O: 19%, BaO: 19
_{%, Nb 2 O 5: 11} %, K 2 O: 1%). This raw material was placed in a magnetic mortar and kneaded for 0.5 to 1 hour using an automatic kneader. The obtained raw material was put in a platinum crucible and melted at 1200 ° C. in air using an electric furnace. After the sample powder was completely melted by primary melting, it was poured into a stainless steel plate and pulverized. Then, it was re-melted as the secondary melting under the same melting conditions as above, and again poured out onto a stainless steel plate to obtain a sample.

(Evaluation) The prepared sample has a refractive index: n _d ,
The softening temperature: Ts and the crystallization temperature: Tc were measured at three points.
Evaluation as a matrix glass for RG was performed. The evaluation method is as follows.

(Refractive index) The powder method was used for measuring the refractive index. First, the test glass is ground in an alumina mortar. Approximately 5 g of diiodomethyl (CH ₂ I ₂ ) is dropped into the test tube (the amount of drop is to be kept short), and the above-mentioned crushed sample is put into the test tube and stirred well. If n _d does not match, the inside of the test tube becomes cloudy, and it is impossible to read characters and the like of printed matter through the test tube. Next, 1-bromonaphthalene was added to this test tube.
(C ₁₀ H ₇ Br) is added dropwise and stirred. This operation is continued until the inside of the test tube becomes transparent and the printed characters can be clearly read. The amount of 1-bromonaphthalene when the test tube becomes transparent is measured. The refractive index n obtained by mixing the two liquids can be generally obtained by the following equation.

[0022] _{n = n a · m a +} n b · m b n a, n b: Liquid a, the refractive index m _a and b, m _b: Liquid a, mol fraction this time mole fraction of b, _{m a = (W a / M} a) / (W a / M a + W b / M b) m b = (W b / M b) / (W a / M a + W b / M b) W a, W _b : weight of liquids a and b _Ma , _Mb : molecular weight of liquids a and b

(Softening Point) A needle-shaped sample glass was prepared, placed in an electric furnace set at a predetermined temperature for 2 hours, and the temperature at which the sample was bent was taken as the softening point.

(Crystallization Temperature) The sample was kept in an electric furnace set at a softening point of + 70 ° C. for 5 hours, and the presence or absence of crystals was examined.

(Measurement results) Refractive index 1.70 to 1.72 Softening point 540 to 570 ° C. Crystallization temperature Softening point + 70 ° C. or more Example 2 (First invention) 32.22 g of SiO ₂ as a glass raw material, Li ₂ CO ₃ :
15.84 g, BaCO ₃ : 42.31 g, Nb ₂ O ₅ : 2
8.50 g (SiO ₂ : 50%, Li ₂ O: 20%, Ba)
O: 20%, Nb ₂ O ₅ : 10%), except that glass was produced in the same manner as in Example 1. When the obtained sample was evaluated in the same manner as in Example 1, the refractive index n = 1.7.
20, softening point Ts = 580 ° C.

Matrix glass of almost the same composition ratio using Na ₂ O, that is, 50% SiO ₂ : Na ₂ O 19
%: BaO 19%: Nb ₂ O ₅ 9%: K ₂ O 1% Glass has a refractive index of 1.707 and SiO ₂ 50%:
_{Na 2 O 20.4%: BaO 19} %: Nb 2 O 5 10.6
% Glass had a refractive index n = 1.708, which clearly increased the refractive index.

Note that SiO ₂ : 52%, Li ₂ O: 19
%, BaO: 20%, Nb 2 O 5: 8%, Na 2 O: 1%
As a result, Ts dropped to 550 ° C.

Example 3 (Second Invention) SiO ₂ : 48%, BaO: 25%, Li ₂ O: 15%,
SiO ₂ corresponding to Y ₂ O ₃ : 10% and Ta ₂ O ₅ : 2%,
A glass was produced in the same manner as in Example 1 except that BaCO ₃ , Li ₂ CO ₃ , Y ₂ O ₃ , and Ta ₂ O ₅ were weighed and used as glass raw materials.

Next, several tens of oxynitride glass fibers having a diameter of 100 to 300 μm were placed on a stainless steel plate, and the above-mentioned molten glass (1100 to 1200 ° C.) was poured from above and allowed to cool naturally. No reaction was observed between the obtained FRG reinforcing fibers and the matrix glass. The refractive index was measured in the same manner as described above, and was 1.705.

[0030] [Example 4] (Third invention) (a) SiO ₂ 36% as a glass material, TiO ₂ 30
%, Na ₂ CO ₃ 28%, Al ₂ O ₃ 3%, K ₂ CO ₃ 3
% And melted at 1150 ° C. for 2 hours to produce glass. The obtained glass has a refractive index of 1.69 and a softening point of 5
It was 50 ° C. This glass was pulverized to about 1 to 10 μm with a pulverizer and heat-treated at 570 ° C. for 5 hours. X-ray diffraction of this glass revealed no crystals.

(B) 38% of SiO ₂ as a glass raw material,
TiO ₂ 32.5%, Na ₂ CO ₃ 23.5%, Cs ₂ CO
₃ 2.0% and BaCO ₃ 4.0% were used. 1
Glass was produced by melting at 150 ° C. for 2 hours. The obtained glass has a refractive index nd of 1.72, a softening point of 570 ° C.,
When crystallization was examined in the same manner as described above, no crystallization was observed at 580 ° C.

(C) 35% of SiO ₂ as a glass raw material,
TiO ₂ 33%, Na ₂ CO ₃ 28%, Al ₂ O ₃ 2%,
Glass was produced by melting at 1150 ° C. for 2 hours using 2% of Cs ₂ CO ₃ . The obtained glass had a refractive index nd of 1.70 and a softening point of 550 ° C., and did not crystallize even at 580 ° C.

Embodiment 5 (Fourth Invention) SiO ₂ , B ₂ O ₃ , BaO, La ₂ O ₃ are mixed in a molar ratio of 30: 4.
It was weighed so as to be 0:10:20. However, for BaO, the same amount of BaCO ₃ was used. The above raw materials were put in a porcelain mortar and mechanically kneaded for 1 hour with a kneader. About 60 g of this raw material was put in a platinum crucible (Rh 10%) and subjected to primary melting in an electric furnace at 1250 ° C. for 20 minutes in air. The molten glass was poured onto a stainless steel plate (for a glass having a similar composition other than the composition of the present invention, crystals were generated on the bulk surface during cooling and covered most of the glass surface in a few seconds). The obtained glass was roughly pulverized, placed in a crucible, and secondarily melted under the same conditions as above. This was again poured onto a stainless steel plate to obtain a sample. The refractive index of the obtained glass is 1.704-
1.712. The glass softens at 650 ° C.
It did not crystallize even at 0 ° C or higher.

In a glass having about 30: 40: 10: 20 mol of SiO ₂ : B ₂ O ₃ : BaO: La ₂ O ₃ , La ₂
It is presumed that O ₃ gives a high refractive index and SiO ₂ gives a high refractive index and at the same time inhibits crystallization of surface crystals.

Using the obtained matrix glass, FRG was manufactured by hot pressing. That is, the glass was pulverized in an alumina mortar and classified to 32 to 125 μm. Matrix, oxynitride glass fiber
(100-300 μmφ, about 10 mm length) and the mold set were subjected to heat treatment in an electric furnace at 300 ° C. for 12 hours to be dehydrated. A sample (6 g of matrix, 0.1 g of glass fiber) was set in a mold at 100 ° C. or higher, and pre-pressed at 50 MPa for 10 seconds using a known hydraulic hot press.

Next, the temperature of the mold was raised to 720 ° C. over about 4 hours, and the temperature was further maintained for 1 hour. Further, the main press was performed at 50 MPa for 30 minutes. Then cool down, about 200
When the temperature reached ° C, the pressure was removed. The obtained glass was colorless and transparent, and no reaction with the fiber was observed.

Example 6 (Fourth Invention) SiO ₂ , B ₂ O ₃ , BaO, and La ₂ O ₃ in a molar ratio of 31: 3
The weight was weighed so as to be 6:18:15. However, for BaO, the same amount of BaCO ₃ was used. These raw materials were put in a porcelain mortar and mechanically kneaded with a kneader for 30 minutes. About 50 g of this raw material was put in a platinum crucible (Rh 10%) and subjected to primary melting in an electric furnace at 1200 ° C. for 15 minutes in air. Next, the molten glass was poured into a stainless steel plate. The obtained glass was roughly pulverized, put into a crucible, and subjected to secondary melting under the same conditions as in the primary melting. This was again poured onto a stainless steel plate to obtain a colorless and transparent glass. This glass has a refractive index of 1.
704, softening point (Ts) 640 ° C.

Using the obtained matrix glass, FRG was manufactured by hot pressing in the same manner as in Example 5. That is, the glass was pulverized in an alumina mortar, and oxynitride glass whiskers (10 to 2) prepared separately were prepared.
0 μm, 25 μm <) 5% by weight were mixed. This sample was placed in a metal mold, set on a hot press, and
The temperature was raised to 700 ° C. over time. After holding at 700 ° C. for 1 hour, pressure was applied at 50 MPa, and the temperature was held at this temperature for 30 minutes. The temperature is lowered while applying pressure, and the pressure is reduced at 200 ° C.
When the temperature reached room temperature, the FRG was removed from the mold. The obtained FRGs are # 400, # 600, # 1000, # 20
Mirror polishing was performed with each of 00 and CeO ₂ abrasives. When the light transmittance of the obtained FRG in the UV-visible range was measured, it showed a transmittance of 30 to 45% in the visible range.

Examples 7 to 12 Glasses were produced in the same manner as in Example 6 using the raw material compositions shown in Table 1 below. Table 1 also shows the refractive index of the obtained glass.

[Table 1] {Mole% of raw material Example}溶解 Dissolution refractive index SiO ₂ B ₂ O ₃ BaO La ₂ O ₃ K ₂ O temperature ━━━━━━━━━━━━━━━━━━━━━ ６ 6 31 36 18 15 1200 1.704 7 30 40 10 20 1230 1.712 8 30 40 8 20 2 1230 1.708 9 29 38 20 13 1220 1.698 10 31 36 20 13 1200 1.698 11 31 36 17 16 1200 1.708 12 31 36 18.5 14.5 1200 1.700 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

[0041]

The matrix glass of the present invention is a nitride glass (oxynitride glass) used as a reinforcing fiber.
Such as high refractive index glass (1.65
~ 1.72) and has a low softening point that can be hot pressed,
Moreover, it is difficult to crystallize near the softening point. Therefore, the oxynitride glass is used as a reinforcing fiber and has excellent translucency.
RG is obtained by hot pressing. In the present invention, FRG
Matrix glass having excellent reduction resistance and a refractive index equal to that of oxynitride glass can be obtained even in hot press treatment during production. Since the glass of the present invention has a high refractive index, it can be used for optical equipment.

Claims (4)

(57) [Claims] 1. A matrix glass for FRG using oxynitride glass fiber as a reinforcing fiber, the chemical composition of which is 45 to 70% of SiO ₂ by mol%,
a ₂ O and / or Li ₂ O 5 to 25%, BaO 5 to 5%
_{25%, Nb 2 O 5 2~15} % and K ₂ O 0 to 20%
And a refractive index of 1.65 to 1.72. 2. A matrix glass for FRG using oxynitride glass fiber as a reinforcing fiber, wherein the chemical composition is 45 to 70% of SiO _{2 in} mole%, and B is
aO 5 to 25%, Li ₂ O 5 to 25%, Y ₂ O ₃ 1 to 1
It was 5% and Ta ₂ O ₅ 0.01~15%, FRG for the matrix glass having a refractive index, characterized in that a 1.65 to 1.72. 3. A matrix glass for FRG using oxynitride glass fiber as a reinforcing fiber, wherein the chemical composition is 30 to 45% of SiO ₂ by mol%,
_{a 2 O 20~30%, BaO 0~5} %, K 2 O 0~1
0%, TiO ₂ 25~35%, a Al ₂ O ₃ 0~5% and Cs ₂ O 0~5%, the refractive index from 1.65 to 1.7
2. A matrix glass for FRG, which is 2. 4. A matrix glass for FRG using oxynitride glass fiber as a reinforcing fiber, the chemical composition of which is SiO ₂ + B ₂ O ₃ 40 to 9 in mol%.
0%, BaO 5~55% and La ₂ O ₃ 5~55%,
And the total amount of these components is 80% or more of the whole,
The molar ratio of SiO ₂ to B ₂ O ₃ is 3.0 / 3.4 to 3.0 /
A matrix glass for FRG, which is 4.3.