JPH059041A - Fiber reinforced glass and manufacture of the same - Google Patents

Abstract

PURPOSE:To improve the strength by heating and pressurizing the glass after a slurry of glass powders to be a matrix is impregnated to oxynitride glass fibers incorponating specified quantity of nitrogen atom. CONSTITUTION:The powders of SiO2, Si3N4, CaO, MgO and Al2O3 are respectively mixed in a specified weight ratio, heated and melted in a N2 atmosphere and the melted mixture is cooled to be spun. SiO2, Si3N4, and M1O, in mol%, are represented with formulae I, II (M1 is Ca or Ca+Mg, M2 is the other metal than the prescribed metal), and Si-M1-M2-O-N based oxynitride glass fibers with N content of >=5atom% are obtained. On the other hand, the organic solvent of n-butanol, etc., and a viscosity modifier are added to the matrix glass powders of 1-20mum particle size and the slurry is prepared. The slurry is added to a slurry bath 6 and the bundle of fibers 5 of the oxynitride glass is introduced into the slurry bath 6 to be impregnated. Subsequently, after it is dried and formed as a sheet, the sheet is laminated, heated and pressurized. Thus, the fiber reinforced glass is obtained.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a high-strength fiber-reinforced glass (FR) reinforced with glass fibers having a high nitrogen content.
G). The fiber-reinforced glass of the present invention has high strength, high toughness, and high transparency, and can be used as window materials for optical sensors, bulletproof window materials, window materials for vehicles, aircraft, deep sea boats, and the like.

[0002]

2. Description of the Related Art In recent years, various composite materials have been used to reinforce various structural materials such as plastic, glass and metal by using various reinforcing fibers. Reinforcing fibers for such composite materials include E glass fibers, S glass fibers, aramid fibers, SiC fibers, carbon fibers and the like.
However, E glass has low strength, rigidity (elasticity), and chemical resistance, and S glass lacks rigidity. Further, the composite material using aramid fiber as the reinforcing fiber has low compressive strength and heat resistance.

As a reinforcing fiber for glass, SiC fiber,
Attempts have been made to use carbon fiber or the like, and the fracture toughness, which is a drawback of glass, is being improved. However, S
iC fiber is a semiconductor and has poor electrical insulation. On the other hand, the carbon fiber has a small fracture elongation of the fiber itself and the fracture toughness of the obtained FRG is insufficient, and the carbon fiber is oxidized at a high temperature of 500 ° C. or higher to deteriorate the performance. Further, since the SiC fiber and the carbon fiber are both black and opaque, the obtained composite material is black and opaque and the transparency, which is a basic characteristic of glass, is impaired. An object of the present invention is to obtain a composite glass material having high fracture toughness (impact resistance), high strength and high transparency.

[0004]

In view of the above-mentioned problems, the present inventors have studied to use oxynitride glass fiber having high elasticity and high strength as a reinforcing fiber of a glass matrix material. The present invention has been completed based on the finding that excellent fiber-reinforced glass can be obtained by using oxynitride glass having a nitrogen content. That is, the present invention provides a fiber-reinforced glass using glass fiber having a nitrogen content of 5 atomic% or more as a reinforcing fiber and a method for producing the same. The oxynitride glass used as the reinforcing fiber in the FRG of the present invention has a structure in which oxygen in the oxide glass is replaced by nitrogen having a bond valence of 3 valences. Therefore, a larger number of chemical bonds are formed than the oxide glass to strengthen the glass network, and it has excellent physical properties such as high transparency and high elasticity and high strength. The oxynitride glass used as a reinforcing fiber in the fiber-reinforced glass (FRG) of the present invention has a nitrogen content of 5 atom% or more, preferably 7 to 30 atom%. When the nitrogen content of the glass fiber is less than 5 atomic%, the glass fiber having sufficient elasticity and strength cannot be obtained, and the fiber reinforced glass having high toughness cannot be obtained.

A preferred glass fiber used as a reinforcing fiber in the FRG of the present invention is an oxynitride glass having a Si-M ₁ -M ₂ -O-N system, and is composed of SiO ₂ , Si.
₃ N ₄ and M ₁ O in mol% The following formula: 65 ≦ (SiO ₂ + 3Si ₃ N ₄ + M ₁ O) × 100 / (100 + 2Si ₃ N ₄ ) <100 (a) 0.7 ≦ (SiO ₂ + 3Si ₃ N ₄ ) / M ₁ O ≦ 2.3 (b) [In the formula, M ₁ is Ca or Ca + Mg, and M ₂ is a metal other than the above. ] Is contained in an amount that satisfies the above requirement. In addition,
Oxynitride glass is SiO ₂ 0 to 40 mol%,
It preferably contains 26 to 70 mol% of CaO, 0 to 20 mol% of MgO and 22 atom% or less of M ₂ and contains 5 atom% or more of nitrogen and has a close cross-linking structure based on Si—N bond.

Therefore, the preferred oxynitride glass as the reinforcing fiber is Si-Ca-M ₂ -O-N or Si.
_{-Ca-Mg-M 2 -O-} N has a glass-based, also metal M ₂
Is Al, Sr, La, Ba, Y, Ti, Zr, Ce, N
a, K, Sb, B, Cr, Pb, V, Sn and the like.
These metals may be used alone or in combination of two or more. That is, a preferable oxynitride glass satisfies the following formula in mol%. 65 ≦ (SiO ₂ + 3Si ₃ N ₄ + CaO + MgO) × 100 / (100 + 2Si ₃ N ₄ ) <100 ・ ・ ・ ・ ・ ・ (a) ′ 0.7 ≦ (SiO ₂ + 3Si ₃ N ₄ ) / (CaO + MgO) ≦ 2.3 ... (b) 'This oxynitride glass is CaO as an essential component.
In the formula, CaO is added CaO or CaO.
Mol% of the compound that can be converted into Further, MgO may be contained together with CaO, and MgO in the above formula is mol% of added MgO or a compound which can be converted into MgO.

The reinforcing fiber used in the FRG of the present invention contains a large amount of Ca as compared with the known oxynitride glass. When the formula (a) is less than 65 mol%, the oxynitride glass crystallizes. If the formula (b) is smaller than 0.7 or larger than 2.3, the nitrogen content of the obtained glass will be small and a glass having a high elastic modulus cannot be obtained.

To produce such oxynitride glasses, (i) SiO ₂ , (ii) Si ₃ N ₄ , or other metal nitrides, (iii) at least one M ₂ O, (iv ) C
Mix aO or CaO + MgO.

Examples of the metal nitride other than Si ₃ N _{4 in} (ii) above include AlN and BN. Examples of the metal oxide (iii) include Al ₂ O ₃ , BaO, Sb ₂ O ₃ , SrO,
Na ₂ O, K ₂ O, La ₂ O ₃ , CeO ₂ , Y ₂ O ₃ , ZrO ₂ , T
iO ₂ , B ₂ O ₃ , Cr ₂ O ₃ , PbO, V ₂ O ₅ , SnO _2, etc.,
Alternatively, carbonates, hydroxides, and oxalates that become these metal oxides by thermal decomposition may be added. Also, C
CaO or Mg instead of aO and MgO by thermal decomposition
You may use the compound used as O, for example, a carbonate, a hydroxide, an oxalate.

These raw materials, in mol%, are of the above formula (a)
The oxynitride glass is obtained by mixing and heating and melting so as to satisfy the requirement ', (b)'. The melting of the mixture is 14
1 minute to 3 hours at 00 to 1950 ° C, heating rate 10 to 8
It is preferably performed at 00 ° C./min in an atmosphere of an inert gas such as nitrogen or argon.

Then, the obtained oxynitride glass is rapidly or slowly cooled. The cooled oxynitride glass is transferred to a spinning device heated to 1100 to 1600 ° C. and spun in an inert atmosphere at a spinning speed of 20 to 3000 m / min to obtain continuous fibers. As another spinning method, oxynitride glass may be cooled from the melting temperature to 1100 to 1600 ° C. in a heating furnace of a spinning device and then spun in an inert atmosphere. In this method, a raw material of oxynitride glass is continuously supplied to a heating furnace in a spinning device by a feeder to directly perform spinning.

The obtained glass has a nitrogen content of 5 to 30 atomic%, an elastic modulus of 100 to 125 GPa, and a tensile strength of 1.0 to 7
Have GPa. If the nitrogen content is less than 5 atom%,
Glass does not show a high elastic modulus. On the other hand, the nitrogen content is 3
If it exceeds 0 atomic%, the glass crystallizes. The nitrogen content is adjusted by the amount of nitride in the raw material. The glass fiber preferably has a diameter of 3 to 50 μm. If the diameter is smaller than this range, the spinning operation becomes difficult. On the other hand, if the diameter is larger than that range, the strength is significantly reduced. The glass fibers may be continuous fibers or short fibers of 0.5 to 100 mm.

The glass fiber may be in the form of cloth, roving, yarn, staple, chopped strand, wool, paper, mat or the like. As the sizing agent, known surface-treating agents for glass fibers such as starch and polyvinyl alcohol may be used for the glass fibers. Further, a softening agent (cationic surfactant), an antistatic agent or the like may be added to the surface treatment agent.

On the other hand, as the matrix glass used in the fiber-reinforced glass of the present invention, a glass conventionally known as a matrix glass of FRG is used. For example,
Lead glass, lead silica glass, flint glass, zinc barium silica glass and the like are preferable.

In the FRG of the present invention, the content of reinforcing fibers is 80% by volume or less. If the content of the reinforcing fiber exceeds 80% by volume, the composite material is not densified such as bubbles remaining in the fiber and transparency is deteriorated.

In order to produce the FRG of the present invention, a known method in which a slurry of glass powder serving as a matrix is prepared, impregnated with a glass fiber for reinforcement, and then heated and melted can be used. To the slurry used here, an organic melting agent such as isopropyl alcohol, n-butanol, sec-butanol and a viscosity modifier such as polyethylene glycol are added, and the matrix glass powder having a particle size of 1 to 20 μm is added thereto. The glass powder concentration of the slurry is preferably 20 to 90% by weight. Oxynitride glass fibers are immersed in this slurry to impregnate the slurry. Then, after drying the fiber bundle impregnated with the slurry,
High-temperature pressure treatment is performed to form fiber-reinforced glass. The molding temperature by the high-temperature pressure treatment is preferably near the softening point of the matrix glass (softening point ± 100 ° C.). Also,
The molding pressure is preferably about 1 to 30 MPa.

[0017]

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

[Example 1] (Production of oxynitride glass fiber) Oxynitride glass fiber for reinforcement was spun by using the apparatus shown in FIG. As a glass material, SiO ₂ (8.6%), Si ₃ N ₄
(19.4%), CaO (59.8%), MgO (6.9)
%), Al ₂ O ₃ (5.2%) [a = 96.2, b = 1.0
0, nitrogen content 23.4 atomic%] was used. The glass raw material 1 was mixed and supplied from the hopper of the spinning device to the molten crucible 2 in the heating device. The mixture in crucible 2 was melted at 1780 ° C. for 12 hours under a nitrogen atmosphere. Then, the melted mixture was cooled to 1570 ° C., spun at 2000 m / min from the bushing 3 and wound on the winder 4 to obtain continuous fibers. The obtained oxynitride glass fiber has a tensile elastic modulus of 214 GPa and a tensile strength of 3.78 GP.
a, the fiber diameter was 12 to 15 μm, the density was 2.89 g / cm ³ , and the number of filaments in the fiber bundle was about 100.

(Production of FRG) Raw material powder of matrix glass [SiO ₂ 58%, Na ₂ O (using Na ₂ CO ₃ ) 16%, PbO 26%] were mixed and melted at 1050 ° C. for 3 hours. A homogeneous glass was obtained. This was crushed with a crusher and sieved to obtain a powder having an average particle size of 1 μm. 85 g of this powder was mixed with 0.13 L of isopropyl alcohol and 24 g of polyethylene glycol (molecular weight 1000) to give a slurry. This slurry was placed in a slurry bath 6 of the apparatus shown in FIG. 1 and the above oxynitride glass fiber bundle 5 was introduced into the slurry bath 6 to impregnate the oxynitride glass fibers with the slurry. The fiber bundle 5 impregnated with the slurry is dried at 100 ° C. for 1 hour, and then 50 × 5
It was cut into a 0 mm sheet. The thickness of the sheet is about 50μ
It was m. Fifty sheets of this sheet were arranged in the same fiber direction and stacked, and heat treated at 400 ° C. for 2 hours. Next, it processed using hot press at 570 degreeC and 10 MPa for 30 minutes. The resulting composite material had a fiber content of about 60% volume. As a result of measuring the light transmittance, as shown in FIG. 3, high transparency was shown at a wavelength of 500 nm or more. The fracture toughness was much higher Toughness comparison with the case of only the matrix is 15~20MPam ^1/2 (0.7~1.0MPam ^1/2).

Example 2 (Production of Oxynitride Glass Fiber) In the same manner as in Example 1, oxynitride glass fiber for reinforcement was spun. As a glass material, SiO ₂ (28.5%), Si ₃
N ₄ (5.0%), CaO (53.5%), MgO (6.0
%), Al ₂ O ₃ (7.0%) [a = 0.94, b = 0.7
3, each of which has a nitrogen content of 7.3 atom%. The glass raw materials are mixed and mixed in a melting crucible under a nitrogen atmosphere for 1
It was melted at 650 ° C. for 12 hours. Then, the molten mixture was cooled to 1500 ° C., spun, and wound to obtain continuous fibers. The obtained oxynitride glass fiber has a tensile elastic modulus of 105 GPa, a tensile strength of 3.5 GPa, and a fiber diameter of 12 to 1
The number of filaments in the fiber bundle was 5 μm, and the number of filaments was about 100.

(Production of FRG) SiO ₂ 64.7%, Na ₂ O (Na ₂ CO ₃ ) as raw material powder for matrix glass
17.8%, PbO17.5%, and
A heat-treated sheet was prepared in the same manner as in Example 1 except that the uniform matrix glass was obtained by melting at 0 ° C. for 3 hours. Next, this sheet was treated with a hot press at 590 ° C. and 10 MPa for 30 minutes. The resulting composite material had a fiber content of about 60% by volume. As a result of measuring the light transmittance, as in Example 1, high transparency was exhibited at a wavelength of 500 nm or more. The fracture toughness was much higher Toughness comparison with the case of only the matrix is 10~13MPam ^1/2 (0.7~1.0MPam ^1/2).

Comparative Example 1 (Production of Oxynitride Glass Fiber) In the same manner as in Example 1, oxynitride glass fiber for reinforcement was spun. As a glass raw material, SiO ₂ (32.0%), Si ₃
N ₄ (3.0%), CaO (52.4%), MgO (6.0
%), Al ₂ O ₃ (6.6%) [a = 0.94, b = 0.7
0, nitrogen content of 4.5 atomic%] was used. The glass raw materials are mixed and mixed in a melting crucible under a nitrogen atmosphere for 1
It was melted at 630 ° C. for 12 hours. Then, the molten mixture was cooled to 1490 ° C., spun, and wound to obtain continuous fibers. The obtained oxynitride glass fiber has a tensile elastic modulus of 98 GPa, a tensile strength of 3.5 GPa, and a fiber diameter of 12 to 15
The number of filaments in the fiber bundle was about 100.

(Production of FRG) SiO ₂ 64.5%, Na ₂ O (Na ₂ CO ₃ ) as raw material powder for matrix glass
19.0%, PbO 16.5% and 125
A heat-treated sheet was prepared in the same manner as in Example 1 except that the uniform matrix glass was obtained by melting at 0 ° C. for 3 hours. Next, this sheet was treated with a hot press at 600 ° C. and 10 MPa for 30 minutes. The resulting composite material had a fiber content of about 60% by volume. The fracture toughness was 0.5 to 1.7 MPam ^1/2 , and the fracture toughness was not significantly improved as compared with the case of only the matrix (0.7 to 1.1 MPam ^1/2 ).

[0024]

The fiber-reinforced glass of the present invention has excellent adhesion between the reinforcing fiber and the matrix glass, exhibits high strength and high toughness (impact resistance), and has high transparency.

[Brief description of drawings]

FIG. 1 is a schematic view showing a specific example of an apparatus for producing the fiber-reinforced glass of the present invention.

FIG. 2 is a schematic view showing a specific example of an apparatus for producing oxynitride glass fiber.

FIG. 3 is a graph showing the transmittance of the fiber-reinforced glass of the present invention.

[Explanation of symbols]

5 fiber bundles 6 slurry bath

Claims (3)

[Claims] 1. A fiber reinforced glass using glass fibers having a nitrogen content of 5 atomic% or more as reinforcing fibers. _2. An oxynitride glass having a Si—M ₁ —M ₂ —O—N glass fiber, wherein the glass fiber is SiO ₂ ,
Si ₃ N ₄ and M ₁ O in mol% are represented by the following formula: 65 ≦ (SiO ₂ + 3Si ₃ N ₄ + M ₁ O) × 100 / (100 + 2Si ₃ N ₄ ) <100 (a) 0.7 ≦ (SiO ₂ + 3Si ₃ N ₄ ) / M ₁ O ≦ 2.3 (b) [wherein, M ₁ is Ca or Ca + Mg, and M ₂ is a metal other than the above. ] The fiber reinforced glass according to claim 1, which is contained in an amount satisfying the following. 3. A method for producing a fiber-reinforced glass, which comprises preparing a slurry of glass powder as a matrix, impregnating the slurry into glass fibers having a nitrogen content of 5 atomic% or more, and then heating and pressing.