JP2016117627A - Production method of glass fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method of glass fibers having a small B amount to be discharged into the atmosphere, and producible inexpensively.SOLUTION: In a production method of glass fibers for melting a raw material batch comprising a mixture of a glass-making feedstock and glass cullet in a glass melting furnace, and for drawing molten glass continuously from a bushing so as to be molded fibrously, the raw material batch containing 25 mass% or more B (boron)-containing glass cullet as the glass cullet is used.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing glass fibers used as a reinforcing material for composite materials.

  Glass fibers (also referred to as glass fibers) used for composite materials with resins are generally produced as follows.

  First, a raw material mixture (called a raw material batch) prepared and mixed to have the desired composition is put into a melting furnace, and glass is heated by burner combustion of heavy oil or gas, or by direct energization, and the surface of the batch Then, the melting is advanced to gradually make a glass melt.

Subsequently, the molten glass is supplied to a molding apparatus called a bushing (also called a spinning furnace). The bushing is a device having a substantially rectangular appearance with a large number of nozzle parts (or orifice parts), and the temperature is controlled so that the viscosity of the molten glass at the tip part of the bushing nozzle is approximately 10 ³ dPa · s. (For example, patent document 1). The temperature at which the viscosity of the molten glass becomes 10 ³ dPa · s is called the molding temperature T _X, and the smaller the temperature difference ΔT _XL between T _X and the liquidus temperature _TL , the more the loss in the glass melt at the bushing nozzle tip. Permeability is likely to occur, and thread breakage is likely to occur. For this reason, it is preferable that ΔT _XL is larger.

  Thereafter, molten glass is spun to produce glass fibers. More specifically, molten glass supplied to the bushing is continuously drawn out from the tip of the bushing nozzle and rapidly cooled to form a filament shape, and a predetermined number of the glass melts to obtain glass fibers.

  The glass fiber manufactured in this way is called a long fiber, and is used for fiber reinforced plastic (FRP) which is a structural member such as a printed wiring board, a car, and an airplane.

JP 2007-39320 A Japanese Patent No. 5420683

Conventionally, a low alkali glass fiber called E glass has been widely used as a reinforcing material for printed wiring boards, FRP, and the like. E glass, although containing B (boron) as a glass component, which is capable of lowering the melting temperature and forming temperature T _X of the glass at the same time enhances the network strength of the glass by introducing the B In addition, the liquidus temperature _TL can also be lowered. However, the raw material containing B is very expensive. Further, when B is heated together with other powdery raw materials in a melting furnace, a part thereof becomes B ₂ O ₃ and evaporates. B lost by evaporation not only leads to a further increase in production costs, but also tends to cause environmental problems when released into the atmosphere. For this reason, the glass fiber composition which hardly contains B is proposed (patent document 2).

But the glass fiber composition such as described in Patent Document 2 that a higher molding temperature T _X, bushing life tends shortened by deformation, resulting in manufacturing cost is increased. Further, since the temperature difference ΔT _XL is small and yarn breakage is likely to occur, productivity is low.

  It is an object of the present invention to provide a glass fiber manufacturing method that can be manufactured at low cost with a small amount of B released into the atmosphere, and a glass fiber manufactured by this manufacturing method.

  As a result of various studies, the present inventors have found that the above object can be achieved by using a glass cullet containing B as a glass composition as a main B supply source, and propose the present invention.

  That is, the glass fiber manufacturing method of the present invention is a method for manufacturing a glass fiber in which a raw material batch composed of a mixture of a glass raw material and a glass cullet is melted in a glass melting furnace, and the molten glass is continuously drawn from the bushing and formed into a fiber shape. The method is characterized in that a raw material batch containing 25% by mass or more of B (boron) -containing glass cullet is used as the glass cullet. Here, the “glass cullet” refers to glass that does not become a product generated in the glass manufacturing process, and waste glass such as recycled glass collected from home appliances. “B (boron) -containing glass cullet” refers to a glass cullet made of glass containing a B (boron) component in its composition.

The method of the present invention adopting the above configuration can reduce the raw material cost since the glass cullet available at low cost is used as the B (boron) supply source. Further, since there is no need to change the glass fiber composition, it is possible to avoid early deterioration of the bushing due to an increase in spinning temperature and deterioration of spinnability. Moreover, since the amount of the B raw material used is reduced and the amount of evaporation of B ₂ O ₃ can be effectively reduced, the burden on the environment can be reduced. In the present invention, the “B raw material” refers to a natural raw material or a chemical raw material containing B (boron). In the present invention, 20% by mass or more of the B ₂ O ₃ content of the target glass fiber composition is It is preferable to prepare the raw material batch so as to be supplied from the B-containing glass cullet.

  If the said structure is employ | adopted, the usage-amount of B raw material can be reduced significantly.

In the present invention, the B-containing glass cullet is preferably made of a glass having a glass composition of 5% by mass or more of B ₂ O ₃ .

  If the said structure is employ | adopted, since glass fiber can be manufactured with the usage-amount of a small glass cullet, the freedom degree of preparation of a raw material batch becomes high.

In the present invention, B-containing glass cullet is preferably made of _{Li 2 O + Na 2 O +} K 2 O 0~2% of glass as a glass composition. Here, “Li ₂ O + Na ₂ O + K ₂ O” means the total content of Li ₂ O, Na ₂ O and K ₂ O.

  If the said structure is employ | adopted, it will become easy to apply this manufacturing method to manufacture of E glass fiber whose content of an alkali metal oxide is 2 mass% or less.

In the present _invention, it is preferable to formulate the raw batch so that the glass containing 3 to 6.3% of B 2 _{O 3} in mass%.

In the present invention, _SiO 2 _50-60% by mass percentage of oxide _{equivalent, Al 2 O 3 10~18%,} B 2 O 3 3~6.3%, 0~5% MgO, CaO 18~28 %, Li ₂ O + Na ₂ O + K ₂ O It is preferable to prepare the raw material batch so that the glass contains 0 to 2%.

  The glass fiber of the present invention is manufactured by the above method.

  Hereinafter, the manufacturing method of the glass fiber of this invention is demonstrated.

  The production method of the present invention includes a step of preparing a raw material batch, a step of melting the raw material batch to form molten glass, and a step of forming the molten glass into a fiber shape.

  First, a process for preparing a raw material batch will be described.

B-containing glass cullet is used as one of the materials constituting the raw material batch. The content of the glass cullet in the raw material batch is preferably 25% by mass or more, 27% by mass or more, and particularly preferably 30 to 50% by mass. If the ratio of glass cullet is too small, the amount of B supply decreases, making it difficult to enjoy the effects of the present invention. Although it is desirable to supplement all necessary B from the glass cullet, if this is difficult, the shortage of the B supply amount may be supplemented with natural raw materials or chemical raw materials. Alternatively, it is possible to use a powdery substance (B recovered material) containing B recovered by cooling and solidifying a gas containing B ₂ O ₃ evaporated in the glass melting process.

In the present invention, the raw material batch is prepared so that 20% by mass or more, 35% by mass or more, particularly 50% by mass or more of the B ₂ O ₃ content of the target glass fiber composition is supplied from the B-containing glass cullet. It is preferable to blend. When this ratio is too low, a large amount of B raw material must be used, and it becomes difficult to enjoy the effects of the present invention.

As the B-containing glass cullet, it is preferable to use a glass cullet containing 5% by mass or more, 8% by mass or more, particularly 10% by mass or more of B ₂ O ₃ as a glass composition. When the content of B ₂ O ₃ of the glass cullet too small, it is difficult to supply a sufficient amount of B from the glass cullet.

The B-containing glass cullet is preferably a glass cullet having a Li ₂ O + Na ₂ O + K ₂ O content of 0 to 2%, 0 to 1%, particularly 0 to 0.5%. When _{Li 2 O + Na 2 O +} K 2 O content is too much, an alkali elution amount of the obtained glass fiber is increased. As a result, when it is used as a reinforcing fiber for a printed wiring board or the like, the adhesive strength at the resin-glass interface decreases, and the mechanical strength tends to decrease. Moreover, it becomes difficult to employ | adopt the method of this invention for manufacture of E glass fiber.

The B-containing glass cullet is specifically expressed in terms of mass percentage of SiO ₂ 50 to 70%, Al ₂ O ₃ 10 to 20%, B ₂ O ₃ 5 to 20%, MgO 0 to 5%, CaO 1 to 20 %, SrO 0-15%, BaO 0-15%, Li ₂ O + Na ₂ O + K ₂ O 0-2%. The glass cullet is preferably made of glass having a composition different from that of the glass fiber to be produced, and is particularly preferably made of glass having a higher B ₂ O ₃ content than the glass fiber to be produced. If it does in this way, it will become possible to introduce B into glass efficiently.

  Next, the process of melting the raw material batch to obtain molten glass will be described.

  The glass raw material batch prepared as described above is put into a glass melting furnace, vitrified, melted and homogenized. The glass is preferably melted at about 1300 to 1600 ° C. A suitable composition of the target glass fiber will be described later.

  Then, the process of shape | molding molten glass in a fiber form is demonstrated.

  First, molten glass that has been uniformly melted is supplied to the bushing. The molten glass supplied to the bushing is continuously drawn out in filament form from a number of bushing nozzles provided on the bottom surface. Various processing agents are applied to the monofilaments drawn in this way, and glass fibers are obtained by focusing each monofilament. The temperature at which the glass fiber is spun (temperature drawn from the bushing nozzle) is preferably 1100 to 1300 ° C.

  The glass fiber formed in this way is processed into chopped strands, yarns, rovings, etc. and used for various purposes.

  Hereafter, the suitable composition and characteristic of the glass fiber produced with the method of this invention are demonstrated. In the following description,% display refers to mass%.

The glass fiber produced by the method of the present invention is a glass containing ₃ to 6.3% by mass of B ₂ O ₃ as a composition, particularly SiO ₂ 50 to 60%, Al ₂ O ₃ 10 to 18%, B ₂ O _3. It is preferable that the glass contains 3 to 6.3%, MgO 0 to 5%, CaO 18 to 28%, Li ₂ O + Na ₂ O + K ₂ O 0 to 2%. The reason why the content of each component is limited as described above will be described below.

SiO ₂ is one of the elements constituting the glass network. The content is preferably 50 to 60%, 50 to 58%, particularly preferably 52 to 56%. If the SiO ₂ content is too small, the structural strength of the glass is remarkably deteriorated and the mechanical strength required for the composite member using glass fibers cannot be satisfied. On the other hand, when the SiO ₂ content is too large, the high temperature viscosity increases. As a result, if an attempt is made to produce such a glass composition to be homogeneous with high efficiency by a melting method, the energy required for melting the glass increases and the production cost increases. In addition, when melting at a low temperature, a process such as pulverizing the raw material to make it fine is necessary, which also increases the manufacturing cost.

Al ₂ O ₃ is a component that suppresses crystal crystallization and phase separation in molten glass. The content of Al ₂ O ₃ is preferably 10 to 18%, 11 to 16%, particularly preferably 12 to 15%. If the content of Al ₂ O ₃ is too small, the liquidus temperature rises and ΔT _XL becomes small, which is not preferable. On the other hand, the Al ₂ O ₃ content is too large, the high temperature viscosity of the glass is increased, the melting property tends to deteriorate.

In B ₂ O ₃ is a glass network structure similarly to SiO _2, is a component that forms the skeleton, rather than increasing the high temperature viscosity of the molten glass as SiO _2, there is work to lower the high temperature viscosity rather . The content of B ₂ O ₃ is preferably ₃ to 6.3%, 4 to 6%, and particularly preferably 4.5 to 5.5%. When B ₂ content of O ₃ is too small, it increased high temperature viscosity, the melting property tends to deteriorate. On the other hand, when the content of B ₂ O ₃ is too large, foreign glass such as scum is likely to be generated in the melting process.

MgO is a component that acts as a flux that makes it easy to melt glass raw materials, and at the same time is very effective in reducing high-temperature viscosity. It is a useful ingredient. The content of MgO is preferably 0 to 5%, 1 to 4%, particularly preferably 1.5 to 3%. If the MgO content is too large, the phase separation of the molten glass increases and ΔT _XL decreases, which is not preferable.

CaO is a component that lowers the high temperature viscosity together with MgO. The CaO content is preferably 18 to 28%, 20 to 25%, and particularly preferably 22 to 25%. When there is too little CaO content, the high temperature viscosity of glass will rise and a meltability will deteriorate easily. On the other hand, when the content of CaO is too large, the phase separation of the molten glass is increased, and ΔT _XL is decreased, which is not preferable.

Li ₂ O, Na ₂ O and K ₂ O which are alkali metal oxide components facilitate the production of a glass melt when heated in a mixed state of a plurality of glass raw materials to form a glass melt. It acts as a so-called flux. It also has the function of reducing the high temperature viscosity. The total amount of Li ₂ O, Na ₂ O, and K ₂ O (content of Li ₂ O + Na ₂ O + K ₂ O) is preferably 0 to 2%, 0 to 1%, particularly preferably 0 to 0.8%. . If the total amount of Li ₂ O, Na ₂ O, and K ₂ O is too large, the amount of alkali elution of the glass increases, the adhesive strength at the resin-glass interface decreases, and the mechanical strength of the printed wiring board tends to decrease. Therefore, it is not preferable.

  In addition to the above components, various components can be further contained.

P ₂ O ₅ is an ingredient that has the effect of preventing the formation of fine crystal nuclei in the molten glass and can lower the liquidus temperature. However, if added in a large amount, the liquidus temperature is increased. The content of P ₂ O ₅ is preferably 0.1 to 2%, more preferably 0.1 to 1%, and still more preferably 0.1 to 0.5%. If the P ₂ O ₅ content is too small, the above effect cannot be obtained.

In order to reduce the high temperature viscosity, SrO and BaO may be contained. The SrO content is preferably 0 to 2%, more preferably 0.1 to 2%, and still more preferably 0.1 to 1.5%. Further, the content of BaO is preferably 0 to 2%, more preferably 0.05 to 1%, and still more preferably 0.05% to 0.5%. If the content of SrO or BaO is too large, the phase separation of the molten glass is increased, and ΔT _XL is decreased, which is not preferable.

One or more clarifiers may be included to reduce foam in the product glass. As the clarifier, for example, SO ₃ , Cl, SnO ₂ , Sb ₂ O ₃ , As ₂ O _{3 and the} like can be used. In this case, the total amount of standard fining agents added is within 0.5%.

In order to improve chemical durability, high temperature viscosity, etc., in addition to the above components, ₃ components each of Cr ₂ O ₃ , PbO, La ₂ O ₃ , WO ₃ , Nb ₂ O ₅ , Y ₂ O ₃ , F, etc. % May be contained. Further, for example, H ₂ , CO ₂ , CO, H ₂ O, He, Ne, Ar, and N ₂ may be contained up to 0.1% as impurities. Further, Pt, Rh, and Au may be contained up to 0.05% or less as impurities.

The glass fiber produced by the method of the present invention preferably has a melting temperature T _melt (temperature at which the viscosity of the glass becomes 10 ^2.0 dPa · s) is 1400 ° C. or lower, 1380 ° C. or lower, particularly 1360 ° C. or lower. If the melting temperature T _melt is too high, the glass must be melted at a high temperature, which increases the consumption of heavy oil, gas, and electricity, leading to an increase in manufacturing costs.

The molding temperature T _X (the temperature at which the glass has a viscosity of 10 ^3.0 dPa · s) is preferably 1210 ° C. or less, particularly preferably 1190 ° C. or less. When T _X is too high, since the glass fiber must be spun at a high temperature occurs, bushing life tends shortened deformed, leading to increase in manufacturing cost.

Note the melting temperature T _melt and shaping temperature T _X can be measured using a platinum ball pulling method.

The liquidus temperature _TL is preferably 1080 ° C. or lower, particularly preferably 1060 ° C. or lower. When _TL is too high, ΔT _LX becomes small and spinnability deteriorates. That is, devitrified substances are easily generated in the glass melt, and yarn breakage is likely to occur. The liquid phase temperature _TL is measured by filling a crushed sample in a platinum boat and placing it in an electric furnace having a temperature gradient for 16 hours, and calculating the temperature of the crystal precipitation point determined by a microscope from the temperature gradient graph of the electric furnace. It can be determined by the method to do.

The temperature difference ΔT _XL between the molding temperature T _X and the liquidus temperature _TL is preferably 100 ° C. or higher, 110 ° C. or higher, and particularly preferably 120 ° C. or higher. If ΔT _XL is too small, spinnability deteriorates.

  Hereinafter, based on an Example, this invention is demonstrated in detail.

  Table 1 shows Examples (Sample Nos. 1 to 5) and Comparative Examples (Sample No. 6) of the present invention. Table 2 shows the composition of the B-containing glass cullet (glass cullet ad) used.

  Each sample was prepared as follows.

  First, various raw materials such as natural raw materials and chemical raw materials and the B-containing glass cullet shown in Table 2 were weighed and mixed so as to have the glass composition shown in Table 1, to prepare a 500 g raw material batch. The B-containing glass cullet was used in the ratio shown in Table 1. The composition of the B-containing glass cullet was confirmed in advance using a fluorescent X-ray analyzer. Next, this raw material batch was put into a platinum rhodium alloy crucible and then melted at 1450 ° C. for 4 hours in an indirect heating electric furnace. Subsequently, the obtained molten glass was poured into a refractory mold and allowed to cool in air to obtain a massive glass sample. The glass sample thus obtained was subjected to various evaluations. The results are shown in each table.

As can be seen from the table, the sample No. 1-5, the molding temperature _{T X} is 1183 ° C. or less, [Delta] T _XL was at 102 ° C. or higher.

On the other hand, sample No. which is a comparative example. 6, ΔT _XL was as small as 80 ° C.

Note B feed rate to the glass fiber composition according to B-containing glass cullet, determined for B ₂ O ₃ content of the glass composition as a target, the ratio of the content of B ₂ O ₃ introduced from the B-containing glass cullet It is a thing.

The molding temperature T _X (the temperature at which the viscosity of the glass becomes 10 ^3.0 dPa · s) was performed as follows. The massive glass sample was crushed to an appropriate size, and put into an alumina crucible so that bubbles were not caught as much as possible. Subsequently, the alumina crucible is heated, the sample is made into a molten state, the measured value of the viscosity of the glass at a plurality of temperatures is obtained by a platinum ball pulling method, the constant of Vogel-Fulcher formula is calculated, and the viscosity curve is created, The glass was measured by a method of calculating the temperature at which the viscosity of the glass becomes 10 ^3.0 dPa · s and the temperature at which the viscosity becomes 10 ^2.0 dPa · s.

The liquid phase temperature _TL is measured by filling a crushed sample in a platinum boat of about 120 × 20 × 10 mm and placing it in an electric furnace having a linear temperature gradient for 16 hours. Calculated from the temperature gradient graph of the electric furnace, this temperature was defined as the liquidus temperature _TL .

Further, the massive glass sample was put into a noble metal pot equipped with a bushing and remelted by energization heating. Thereafter, various treatment agents were applied to the monofilament continuously drawn out in a filament form from the bushing nozzle, and the glass fibers were obtained by focusing each monofilament. In this example, a method of once producing a lump glass sample and remelting and spinning it was adopted. However, when producing on an industrial scale, the molten glass was directly supplied to the bushing for spinning. It is preferable to adopt the method to do.

Claims (7)

  A glass fiber manufacturing method in which a raw material batch composed of a mixture of a glass raw material and a glass cullet is melted in a glass melting furnace, and the molten glass is continuously drawn from a bushing and formed into a fiber shape. ) A raw material batch containing 25% by mass or more of glass cullet containing is used. 2. The glass according to claim 1, wherein the raw material batch is prepared so that 20% by mass or more of the B ₂ O ₃ content of the obtained glass fiber composition is supplied from a B (boron) -containing glass cullet. A method for producing fibers. The method for producing glass fibers according to claim 1, wherein the B (boron) -containing glass cullet is made of glass having a glass composition of 5% by mass or more of B ₂ O ₃ . B (boron) containing glass cullet, process for producing a glass fiber according to claim 1, characterized in that it consists of _{Li 2 O + Na 2 O +} K 2 O 0~2% of glass as a glass composition. The method for producing glass fibers according to any one of claims 1 to 4, wherein the raw material batch is prepared so as to be a glass containing ₃ to 6.3% of B ₂ O ₃ by mass%. SiO ₂ 50-60%, Al ₂ O ₃ 10-18%, B ₂ O ₃ 3-6.3%, MgO 0-5%, CaO 18-28%, Li ₂ O + Na in terms of mass percentage in terms of oxide process for producing a glass fiber according to claim 1, characterized in that formulating raw batch so that _{2 O} + K _{2 O 0~2%} glass containing.   A glass fiber produced by the method according to claim 1.