JP3132234B2 - Glass long fiber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a long glass fiber, particularly to a long glass fiber having high tensile strength and excellent water resistance.

[0002]

2. Description of the Related Art At present, long fibers having a glass composition called "E glass" in a trade name are produced in large quantities and widely used in various fields such as plastic reinforcement, rubber belt core materials, and electrical insulation. ing. The viscosity of the glass is low. For example, the spinning temperature (temperature at a viscosity of 1000 poise), which is a measure of the spinning temperature, is about 1200 ° C., so that the melting temperature and the spinning temperature are low, and the glass can be easily manufactured. However, since it has low tensile strength and poor water resistance, it cannot be used in applications requiring such properties.

On the other hand, for applications requiring high strength, MgO
—Al ₂ O ₃ —SiO ₂ ternary glass fiber is used, and its basic composition is MgO 10 Al ₂ O ₃ 25 SiO ₂ 65 by weight. (Japanese Patent Publication No. 48-30125) The liquidus temperature of this glass composition is 1471 ° C. (2680 ° F.), the spinning temperature is about 1460 ° C., 260 ° C. or more higher than E glass, and it is difficult to melt and The liquidus temperature is higher than the spinning temperature, the spinning requires a high temperature, and the life of the platinum pot for spinning is short, resulting in an increase in cost.

[0004] melting of the glass, in order to improve spinnability, in addition to the three components of the _{MgO-Al 2 O 3 -SiO 2} , the fourth component further has been developed a composition obtained by adding the fifth component . The glass composition plus B ₂ O ₃ as the fourth component is described in JP-B 42-23593, Kokoku 4-48739. The raw material of B ₂ O ₃ is expensive and causes an increase in cost. Further, when the raw material batch of the glass composition is melted in a melting furnace of a crucible or a hot top, the B ₂ O ₃ volatilizes and shortens the life of the furnace. This causes inhomogeneities such as striae in the glass base, which may cause yarn breakage during spinning. The glass composition Sho 42-23593 plus Li ₂ O as a fourth component, in JP-B-43-11762, P
_The glass composition to which ₂ O ₅ is added is described in JP-A-48-30717, but the raw materials of Li ₂ O and P ₂ O ₅ are expensive, which leads to an increase in cost. In addition, Japanese Patent Publication No. 45-11
No. 228 describes a glass fiber having a composition to which As ₂ O ₃ is added as a fourth component, but As ₂ O ₃ has a problem in volatilization and a problem in work safety due to its toxicity.

[0005]

DISCLOSURE OF THE INVENTION The present invention is based on the above-mentioned requirements and the problems of the prior art. Accordingly, the present invention provides a glass composition for fibers having good water resistance and high strength, especially volatile components and harmful substances at the time of melting. It is another object of the present invention to provide a low-cost glass composition for glass and a long glass fiber that does not contain toxic substances.

[0006]

SUMMARY OF THE INVENTION The present invention is directed essentially to Na
_It consists of ₂ O, MgO, Al ₂ O ₃ , SiO ₂ , and the proportion of these components is Na ₂ O 0.2-1.5 Li ₂ O 0-0.5 MgO 12-20 Al ₂ by weight%. O ₃ 17-25 SiO ₂ 61-68 B ₂ O ₃ 0-0.5, which is a long glass fiber characterized by having a composition in which the total is at least 98% by weight. Na ₂ O 0.3 to 1.3 Li ₂ O 0 to 0.3 MgO 13 to 18 Al ₂ O ₃ 18 to 23 SiO ₂ 63 to 67 B ₂ O ₃ 0 to 0.5, and K ₂ O + CaO + SrO + TiO ₂ It is a long glass fiber having a composition in which the total of + Fe ₂ O ₃ is 0 to 2% by weight.

The inventors of the present invention have conducted detailed studies on a ternary glass composition of MgO, Al ₂ O ₃ and SiO _{2 in} order to solve the problems of the present patent. Within the range, it has been found that fibers having excellent meltability and spinnability and high strength can be produced. As a result of further studies, it has been found that by using Na ₂ O in the above-mentioned limited range, a glass composition having improved water resistance and further excellent meltability and spinnability can be obtained. To the Japanese Patent Publication No. 43-11762, Li ₂ O is added as a fourth component, and Na ₂ O (K ₂ O) alone or L 2
It is described that even when used in combination with i ₂ O, better results were not obtained than with Li ₂ O alone. FIG. 1 shows the results of comparison of the water resistance of Na ₂ O and Li ₂ O by the present researchers. This figure shows the water resistance of a glass obtained by adding Na ₂ O and Li ₂ O to MgO 15 Al ₂ O ₃ 20 SiO ₂ 65 with the following base composition and weight%, and the Japan Optical Glass Industry Association Standard JOGIS. The weight loss (%) measured according to the durability measurement method (however, boiling for 8 hours) is shown. As is clear from the figure,
It was found that when Li ₂ O was added, the water resistance was lowered, and when Na ₂ O was added within the above range, the water resistance was improved.

Next, the reasons for limiting the composition range of the present invention will be described.

[0009] Na ₂ O: It is effective to lower the liquidus temperature at the same time as lowering the viscosity, to improve the meltability and spinnability, and to improve the water resistance. 1.
If it exceeds 5% by weight, the water resistance will decrease. It is more preferably at most 1.3%, further preferably at most 1.0%.
If it is less than 0.2% by weight, the effect of improving the meltability and spinnability is small, more preferably 0.3% by weight or more.

Li ₂ O: At the same time as lowering the viscosity, it further lowers the liquidus temperature and improves the meltability and spinnability. However, the water resistance is reduced, especially when it exceeds 0.5% by weight. The decline is significant. The amount of thus Li ₂ O is 0 to 0.5 wt%, more preferably from 0 to 0.3 wt%.

If MgO exceeds 20% by weight, the liquidus temperature becomes too high than the spinning temperature, making spinning difficult. It is more preferably at most 18%. If it is less than 12% by weight, the viscosity becomes too high, and the melting temperature and the spinning temperature increase. It is more preferably at least 13% by weight.

When Al ₂ O ₃ exceeds 25% by weight, the liquidus temperature becomes too high than the spinning temperature and spinning becomes difficult. It is more preferably at most 23%. If it is less than 17% by weight, the water resistance is lowered and the liquidus temperature is too high than the spinning temperature, making spinning difficult. It is more preferably at least 18% by weight, and further preferably at least 19% by weight.

If the content of SiO ₂ exceeds 68% by weight, the viscosity becomes too high, and the melting temperature and the spinning temperature increase. It is more preferably at most 67%, further preferably at most 66% by weight. It is. If it is less than 61% by weight, the liquidus temperature becomes too high than the spinning temperature, and spinning becomes difficult. It is more preferably at least 63% by weight.

B ₂ O ₃ : It is effective for lowering the melting temperature and spinning temperature. However, since the volatilization shortens the life of the furnace and increases the cost, the content is set to 0.5% by weight or less.

[0015] In addition to the above, K
₂ O, alkaline earth oxides (CaO, SrO), Ti
O ₂ , Fe ₂ O _{3 and the} like may be contained in an amount of 2% by weight or less. However, As ₂ O ₃ and F ₂ are poisons and harmful substances, and are not substantially contained. However, if each is 0.05% by weight or less, they are acceptable as impurities.

The long glass fiber of the present invention has a diameter of usually 2 to 20 μm, though it varies depending on the use.

[0017]

EXAMPLES The compositions of the eight examples and four comparative examples according to the present invention and the measurement results of the spinning temperature, liquidus temperature, weight loss (%) in the water resistance test and monofilament strength of the obtained glass are shown below. The results are shown in Table 1.

[0018]

[Table 1]

[0019]

[Table 2]

[0020]

[Table 3]

First, a first embodiment will be described. The compositions shown in Table 1 were prepared using ordinary glass raw materials such as clay, talc, alumina and soda ash.
Using a platinum crucible, mix the above batch at 1550 ° C for 16
The mixture was melted for an hour, poured out onto an iron plate, and allowed to cool to room temperature to obtain a sample glass.

The viscosity of the sample glass in a high temperature region was measured by a platinum ball pull-up type automatic viscosity measuring device. The liquidus temperature was measured as follows. The sample glass was pulverized, passed through a 1680 μm sieve, and the glass particles remaining on the 1190 μm sieve were immersed in ethanol, ultrasonically cleaned, and dried in a thermostat. 1mm opened in a row on a platinum boat
These glass grains are arranged one by one in a number of holes having a diameter of 1200
After being kept in a gradient furnace at 炉 1500 ° C. for 2 hours, it was taken out of the furnace, the devitrification generated on the glass particles was observed, and the highest temperature generated was defined as the liquidus temperature. In addition, the water resistance of the sample glass is determined by the Japan Optical Glass Industrial Association standard JOGIS.
The optical glass was measured in accordance with a method for measuring the chemical durability (boiling for 8 hours). The measurement of the monofilament strength was performed as follows. 1.5 mm crushed sample glass
Into a pot of platinum rhodium alloy having a single nozzle of a diameter, and re-melted at the spinning temperature shown in Table 1;
The glass was drawn out at a speed of 000 m / min, and a glass fiber (monofilament) having a diameter of about 10 μm was collected without contact between the nozzle and the winding device. The tensile strength of this monofilament was measured according to JIS R7601-1986 carbon fiber test method (6.6.1 single fiber test).

In Examples 2 to 8, sample glasses were prepared in the same manner as in Example 1, and the spinning temperature, liquidus temperature, weight loss (%) in a water resistance test, and monofilament strength were measured.

In each embodiment, the spinning temperature was 142.
The liquidus temperature is 5 ° C. or less, the liquidus temperature is lower than the spinning temperature, and the meltability and the spinnability are excellent. The weight loss (%) in the water resistance test was 0.055% or less, and the monofilament strength was 28%.
It was 0 kg / mm ² or more, and water resistance was good, and a high-strength glass long fiber was obtained.

Comparative Examples 1 and 2 are compositions not included in the present invention, and a sample glass was prepared in the same manner as in Example 1;
The spinning temperature, liquidus temperature and weight loss (%) in the water resistance test were measured. Comparative Example 1 has good water resistance and a low spinning temperature of 1344 ° C., but the liquidus temperature is 57 ° C. lower than the spinning temperature.
And it is difficult to spin. Comparative Example 2 has poor water resistance,
The spinning temperature is 1425 ° C. or lower, but the liquidus temperature is 73 ° C. higher than the spinning temperature and spinning cannot be performed. Comparative Examples 3 and 4 are commercially available glass and E glass compositions, respectively.
A sample glass was prepared in the same manner as described above, and the spinning temperature, liquidus temperature, weight loss (%) in a water resistance test, and monofilament strength were measured. Comparative Example 3 has good water resistance and high fiber strength, but has a high spinning temperature of 1460 ° C, a liquidus temperature of 11 ° C higher than the spinning temperature, and requires a high temperature for melting and spinning. On the other hand, Comparative Example 4 has a low spinning temperature of 1225 ° C., a liquidus temperature of 128 ° C. lower than the spinning temperature, and is excellent in meltability and spinnability, but has poor water resistance and low fiber strength.

[0026]

As described above, according to the present invention, a long glass fiber which does not contain volatile components, harmful substances and poisonous substances at the time of melting, can be produced at low cost, has good water resistance, and has high strength. can get.

[Brief description of the drawings]

FIG. 1 is a graph showing water resistance of an example of the present invention.

Continuation of front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C03C 1/00-14/00

Claims (2)

(57) [Claims] 1. The method according to claim 1, wherein Na ₂ O, MgO, Al ₂ O ₃ ,
Consisting of SiO ₂ and the proportion of these components
And Na ₂ O 0.2 to 1.5 Li ₂ O 0 to 0.5 MgO 12 to 20 Al ₂ O ₃ 17 to 25 SiO ₂ 61 to 68 B ₂ O ₃ 0 to 0.5, and their total is at least A glass long fiber having a composition of 98% by weight. 2. Essentially, Na ₂ O, MgO, Al ₂ O ₃ ,
Consisting of SiO ₂ and the proportion of these components
In _{Na 2 O 0.3~1.3 Li2O 0~0.3 MgO 13~18} Al 2 O 3 18~23 a _{SiO 2 63~67 B 2 O 3 0~0.5} , total 0 of K2O + CaO + SrO + TiO2 + Fe2O3 2. The glass long fiber according to claim 1, wherein the amount is 2 to 2% by weight.