JPH035343A - Fiberglass composition - Google Patents

Abstract

PURPOSE:To obtain the fiberglass composition melting at industrial temp., capable of being easily formed and excellent in tensile strength by mixing SiO2, Al2O3, CaO and MgO with Y2O3, La2O3 or CeO2 in a specified ratio. CONSTITUTION:The glass composition contains 52-56wt.% SiO2, 28-32wt.% Al2O3, 9-12wt.% CaO and MgO and 4-7wt.% of >=1 kind among Y2O3, La2O3 and CeO2. The content of SiO2 is appropriately controlled to 52-56wt.% for the composition, the SiO2 forms an eutectic alloy with the Al2O3, CaO and MgO, hence the liq. phase temp. is lowered, and melting is facilitated. The content of Al2O3 is appropriately controlled to 28-32wt.%, hence the liq. crystal temp. is lowered, and melting is facilitated. When the content of the CaO and MgO in total is controlled to 9-10wt.% practically in balance with each other, the liq. phase temp. is lowered, and fiberizing is facilitated. The content of the rare-earth elements is controlled to >=4wt.%, and the tensile strength of the fiber is improved without drastically increasing the liq. phase temp.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a fiberglass composition with excellent tensile strength.

[Prior art and its problems]

Conventionally, fiberglass has been widely used as a reinforcing material for composite materials (
It is used. The well-known E-glass fiber has a tensile strength of 280 kg/mm" and is excellent as a reinforcing material for composite materials used in boat fishing. However, it is not strong enough for belt pulleys, timing belts, etc. that require high tension or are subject to sudden tension. is insufficient.

In oxide glass fibers, it is estimated to reach 500 kg/mm2 or more based on molecular bond energy, etc. Therefore, there is an urgent need to develop a practical glass fiber with a tensile strength close to this.

SiO □ 65% by weight as a substitute for the E glass
(hereinafter simply referred to as %), AIZO:l 25%, MgO
The composition disclosed in British Patent No. 1209244 (commonly known as S glass) represented by 10% or 5i
Oz 60χ, AIZO325%, MgO6%, CaO
There is a composition disclosed in French Patent No. 1435073, which is represented by 9% (commonly known as R glass), and
Although it has been described that fiber tensile strength is extremely superior to glass, it is far from reaching the strength of 500 kg/mm2.

The object of the present invention is to melt at an industrial temperature of 1,650°C or less, to easily mold, i.e., form fibers, and to be superior to conventionally known products, with a weight of 450 kg/mm.
``The purpose of this invention is to provide a fiberglass composition having a tensile strength of the above.''

[Means for solving problems]

In the present invention, in weight%, Si0□52-56, AIZ032
8-32, CaO and MgO9-12, Y2O
3. A fiberglass composition in which one or more of La2O3 and CeO is 4 to 7.

In the composition range of the present invention, Sing is preferably in the range of 52 to 56%, and eutectic melting with A1zO3, CaO, and MgO lowers the liquidus temperature and facilitates melting.

If it is less than 52%, moldability, that is, fiber ringing will be insufficient, and the liquidus temperature will also rise. When it exceeds 56%, the tensile strength of the fiber decreases or the liquidus temperature increases.

A preferable content of Ah03 is in the range of 28 to 32%, which lowers the liquidus temperature and facilitates melting. If it is less than 28%, the tensile strength of the fiber will decrease, and if it exceeds 32%, fiber ring will be insufficient.

By using a total of 9 to 12% of CaO and MgO in a substantially balanced manner, the liquidus temperature is lowered and fibering is facilitated. When CaO and MgO are less than 9%, the liquidus temperature increases and the meltability deteriorates. On the other hand, if it exceeds 12%, the tensile strength of the fiber decreases, resulting in poor physical properties.

By introducing 4% or more of one or more of these rare earth elements, Y2O3, LazO3, or Cent, the tensile strength of the fiber can be improved without significantly increasing the liquidus temperature. No significant effect was shown. On the other hand, if it exceeds 7%, the liquidus temperature will rise and melting will become difficult, so the content should be 7% or less.

Note that among these, Y2O3 has a relatively large effect of increasing tensile strength as a fiber.

Furthermore, the introduction of these rare earth elements is effective in improving chemical durability.

In carrying out the present invention, commercially available and easily available raw materials may be used as the raw materials for each component, such as 5i (h; silica sand,
AhO3 + aluminum hydroxide, Cab; calcium carbonate, ) 1gO; magnesium carbonate, YZO3 + yttrium oxide, LazO: +; lanthanum oxide, CeO,;
Cerium oxide or the like is used.

Impurity components of 0.5 to 0.6% or less, such as Nazo,
There is no problem in mixing K2O, Pez03, and Mn0z. Z
If the rO2 content is 1.5% or less, chemical durability and tensile strength will be improved, but if it exceeds this, melting and fibering will deteriorate.

In addition, 1% or less of CaFz, AS20.
．． 5b203, CaSO4, etc. may be mixed.

After preparing these raw materials to the desired composition, weighing them, and mixing them, use any melting means such as a tank furnace or a crucible furnace to melt them at 1650°C or lower.
It can be melted and homogenized in about 4 hours or less, and furthermore, it can be introduced into a spinning furnace and easily fiberized at less than 1500°C.

The present invention will be explained below based on Examples.

〔Example〕

After preparing the raw materials based on the compositions of Examples 1 to 5 and Comparative Examples 1 to 5 shown in Table 1, the raw materials were filled into a platinum crucible and heated in an electric furnace for 1
Melting was carried out at an appropriate temperature and time of 550° C. to 1700° C. for 2 hours to 4 hours. Thereafter, the molten glass was taken out, and after cooling, a small piece was collected and the liquidus temperature was measured using a temperature gradient furnace using a conventional method.

Next, the glass was put into a platinum-rhodium fission spinning furnace and
The glass was drawn out from a spinning nozzle with a diameter of about 1.7 mm at an appropriate temperature of ~1500°C to obtain a fiber with a diameter of about 9 μm. The tensile strength of each fiber sample was measured using a strength testing machine.

The melting temperature-time, liquidus temperature, spinning temperature, and tensile strength test results are also shown in Table 1.

As is clear from Table 1, Examples 1 to 5 according to the present invention can be melted at 1650° C. or lower, have good spinnability, and have excellent fiber tensile strengths of 450 kg/mm” or higher.

On the other hand, Comparative Example 1 has a high liquidus temperature and high viscosity, so the melting temperature is high and the spinning temperature is also high. Furthermore, the fiber tensile strength does not reach 450 kg/mm2.

Comparative Example 2.3 is also not sufficient in tensile strength.

In Comparative Example 4, the amount of rare earth introduced was excessive, and it did not melt even at 1700°C, so it lacked practicality. It is clear that Comparative Example 5 is inferior to the Examples in all respects, as the amount of rare earth introduced is too small and does not show any obvious effect on improving the fiber tensile strength.

〔Effect of the invention〕

According to the present invention, it can be melted at 1650° C. or lower, has excellent tensile strength as a fiber, and has excellent durability even when used as a composite material that is constantly subject to tensile force, such as a tamming belt.

Claims (1)

[Claims] 1) In weight%, SiO_252-56, Al_2O_3
28-32, CaO and MgO9-12, Y_
A fiberglass composition characterized in that one or more of 2O_3, La_2O_3, or CeO_2 consists of 4 to 7.