JP2011011969A - Method of manufacturing glass fiber and glass fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a glass fiber by which the manufacturing yield is remarkably improved by suppressing the generation of bubbles formed during the melting of glass to remove the bubbles incorporated in the glass fiber to attain high non-defective rate and the glass fiber manufactured by the manufacturing method.SOLUTION: In the method of manufacturing the glass fiber in which molten glass after passed through holding temperatures of many stages in a glass melting vessel is spun from a nozzle, the content of SOin a glass raw material mixture charged in the glass melting vessel in the first melting step is controlled to ≥0.05 mass% and ≤0.30 mass% per total quantity of the glass raw material mixture, the maximum holding temperature A in the first melting step is ≥1,350°C and the maximum holding temperature B in the melting stages on and after the second melting stage is higher than the maximum holding temperature A in the first melting step.

Description

  The present invention relates to a manufacturing method for manufacturing glass fiber used as a material constituting a printed wiring board or the like used as an electronic component, and a glass fiber manufactured by this manufacturing method.

  Many of the structural materials that support the latest technological innovations continue to be selected from the existing materials in terms of performance and function, resulting in the current configuration. For example, various printed circuit boards used in the electronics industry have been proposed for various manufacturing methods and numerous structural materials, but glass fibers are available for mechanical strength, electrical insulation, and economical availability. It has the advantage of being easy to do, and since it is generally superior to other materials, it continues to be one of the main components constituting the printed wiring board. Glass fibers used in such applications are continuously molded and spun using a precious metal heat-resistant bushing (also referred to as a platinum heating vessel) having a substantially rectangular appearance. This is generally done. The bushing is provided with a large number of nozzles in the vertical direction at the bottom, and glass glass is obtained by drawing molten glass made homogeneous in a glass melting furnace from the nozzle. And the sizing agent is apply | coated to the surface of the obtained glass fiber, a twist is provided, and it winds up and a predetermined | prescribed glass yarn winding body is obtained.

  In order to manufacture a printed wiring board, various processing is further performed from this glass yarn winding body. The manufacturing process of the printed wiring board is, for example, as follows. First, the glass yarn unwound from the package of the glass yarn wound body is warped with a warper, and is secondarily sized with a gluing machine and wound from a section beam to a room beam, and this is used as a warp. On the other hand, a glass yarn wound package is unwound and used as a weft, and a glass cloth is woven using a weaving apparatus such as an air jet loom. Organic components adhering to the woven glass cloth are removed by heat incineration (heat deoiling), immersed in a treatment solution containing a silane coupling agent and dried (surface treatment), and then a matrix such as an epoxy resin. A prepreg impregnated with resin is produced. One or a plurality of the prepregs thus produced are laminated, a conductor such as a copper foil is attached, and the resin is cured by heating and pressing to produce a laminated board for a printed wiring board. The laminated board obtained in this way forms a desired circuit pattern on the conductors on both sides, and forms a through hole with a drill or a laser. Next, by performing electroless copper plating or the like, a double-sided printed wiring board having the prepreg portion as an insulating layer and the double-sided conductor portion and the copper-plated through-hole portion as a conductor layer is manufactured. A multilayer printed wiring board is manufactured from the double-sided printed wiring board by a sequential molding method, a build-up molding method, or the like.

  In recent years, with the rapid development of the electronics industry, printed wiring boards have been improved in various ways so that they are lighter and thinner and moreover electronic components can be mounted at high density. In many of such efforts, various demands have been made for glass fiber, which is a basic structural material constituting a printed wiring board, and improvements corresponding to the demands have been made. For example, Patent Document 1 discloses a treatment with a silane coupling agent and ammonium chloride as a method for preventing the generation of voids that are problematic when molding a printed wiring board. Further, in Patent Document 2, in order to improve warpage, twisting, etc. that occur when the printed wiring board is thinned, water-soluble epoxy resin is used as a primary sizing agent, and it can be dealt with by degreasing and opening treatment by water flow processing. The invention is disclosed. Further, Patent Document 3 discloses an invention in which a predetermined amount of a water-soluble urethane resin and / or a water-soluble epoxy resin is attached to the glass surface as an object of improving the change with time of the insulation resistance. Patent Document 4 discloses an invention of a glass fiber composition having a dielectric constant at 1 MHz of 4.5 or less.

JP-A-6-112608 JP-A-9-67757 Japanese Patent Laid-Open No. 9-209233 Japanese Patent Publication No. 6-39338

  However, the inventions that have been made so far are not sufficient from the standpoint of obtaining high-quality glass fibers that are used in printed wiring boards and the like that achieve higher-density mounting and exhibit desired performance. . Glass fibers used for printed wiring boards rarely generate hollow fibers called hollow fibers due to fine bubbles mixed in molten glass at the time of production. This hollow fiber has a great influence on physical performance such as strength of glass fiber. Further, the hollow fiber is considered to be a cause of a decrease in insulation reliability because it becomes a fatal defect such as an insulation failure when a plating solution enters in a plating process of a conduction hole during production of a printed wiring board. In other words, there is a concern that the inclusion of hollow fibers may lead to a decrease in insulation reliability more than before due to an increase in the number of holes provided in the wiring board due to a higher density of the printed wiring board and a narrower spacing. . Therefore, when a printed wiring board is manufactured, when a fiber with a thin fiber diameter, that is, a glass fiber with a fine count is adopted, it is required as a more important point that there is no mixing of bubbles in the glass fiber. Yes. Moreover, as the glass fiber diameter becomes smaller, bubbles in the molten glass tend to cause fiber cutting during the production of the glass fiber. In other words, the presence of bubbles in the glass is not preferable because it reduces the yield of glass fiber production in addition to reducing the performance of the glass fiber as a product.

  The present invention has been made in view of the above circumstances, and by suppressing the remaining of bubbles generated when melting glass, as a result, by removing bubbles mixed in glass fibers, a high yield rate is achieved. It is an object of the present invention to provide a glass fiber manufacturing method for dramatically improving the glass fiber manufacturing efficiency, that is, the manufacturing yield, and a glass fiber having excellent quality manufactured by this manufacturing method.

The glass fiber manufacturing method of the present invention is a glass fiber manufacturing method for spinning molten glass from a heat-resistant nozzle after passing through a plurality of melting stages having different holding temperatures in a glass melting container, wherein the first melting stage In the first melting stage, the SO ₃ content in the glass raw material mixture charged into the glass melting vessel is 0.05% by mass or more and 0.30% by mass or less with respect to the total amount of the glass raw material mixture. The maximum holding temperature of the molten glass is 1350 ° C. or higher, and the maximum holding temperature in the melting stage after the second melting stage is higher than the maximum holding temperature in the first melting stage.

The manufacturing method of the glass fiber of this invention is the structure as shown below. First, various natural raw materials or chemical raw materials are weighed so as to have a predetermined composition in advance. Subsequently, the glass raw material mixture prepared by mixing them is continuously or intermittently charged into a heat-resistant container using a charging device and heated to a high temperature. The molten glass thus obtained is made of a noble metal such as a platinum alloy, and is continuously drawn out from the tip holes of a plurality of nozzles arranged in the vertical direction. Thereafter, the thin stream-like molten glass drawn out is cooled by a cooling device or the like to form glass fibers. In the present invention, in the production of the glass fiber as described above, it is a production method in which molding is performed after a multi-stage holding temperature such as a first melting stage and a second melting stage during melting. Then, in the first melting stage to be put into a heat-resistant container for melting glass, that is, at the stage where a glass raw material mixture containing various natural raw materials or chemical raw materials is melted, it is put into the glass melting container in the raw materials. When the SO ₃ content in the glass raw material mixture is chemically analyzed and quantified, the value is within the range of 0.05 or more and 0.30 or less when the mass of the glass raw material mixture is 100. In the present invention, the maximum holding temperature of the molten glass measured in the first melting stage is 1350 ° C. or higher (1623.15 K in absolute temperature). And this invention, after the first melting stage, the molten glass after passing through a thermal history lower than the maximum holding temperature of the first melting stage, and the second, third, etc. When melting and melting at a temperature condition having the maximum holding temperature in each melting stage after the first melting stage, in the melting stage after the second melting stage, it is higher than the maximum holding temperature in the first melting stage. This is a manufacturing method in which glass is melted at a holding temperature.

  In the present invention, the term “melting stage” has the following meaning. After the temperature of the molten glass passes the maximum holding temperature at the time of glass melting, it is called the “first melting stage” until it passes through the desired low temperature that is at least 20 ° C. lower than the maximum holding temperature. The process of lowering the temperature to the desired low temperature through the next maximum holding temperature is called the “second melting stage”. Therefore, the second and subsequent melting stages such as the third and fourth are also used in the same manner as described above to represent multi-stage melting conditions. That is, the “melting stage” represents a glass melting temperature history having one maximum holding temperature.

  Further, in the present invention, the term “holding temperature” refers to the fact that the temperature of the molten glass is ± 5 in actual measurement values by adopting heating conditions that cause the molten glass to have a thermal history that is intentionally held at a predetermined temperature. This indicates a state in which the state within the range of ° C. continues for 10 minutes or more. The heating conditions that will bring the molten glass with a thermal history that is intentionally maintained at a predetermined temperature are to control and adjust various conditions such as furnace pressure, fuel supply speed, and raw material charging speed in order to achieve that temperature. Is realized.

  In the method for producing glass fiber of the present invention, the glass is cooled to room temperature once after the first melting stage, and then the maximum holding temperature higher than that of the first melting stage after the second melting stage may be set. After the melting stage, the temperature may be lowered to a desired low temperature without cooling to room temperature, and the maximum holding temperature higher than that of the first melting stage may be set after the second melting stage. That is, the molten glass is cooled to obtain a solid glass (also called glass cullet or material glass), and the solid glass may be heated again, and the molten glass is melted without temporarily forming the solid glass. The glass melting temperature may be changed stepwise, and the glass fiber may be produced by satisfying a holding temperature condition higher than that of the first melting stage in the process and guiding the molten glass to the forming zone. Which one to select may be selected according to constraints such as economic efficiency and manufacturing equipment.

The SO ₃ content in the glass raw material mixture is expressed in terms of mass%, but in addition to the above notation, a small amount of content in the glass raw material is expressed as a result obtained by ion chromatography or the like. The SO ₃ content per gram of the raw material mixture may be expressed as a value expressed as μg (microgram), that is, in units of μg / g, or may be expressed in mg (milligram) / kg (kilogram). This value may also be displayed in ppm. However, in the case of ppm notation, the value that becomes the denominator becomes unclear, so in that case, the value that becomes the denominator, for example, per 100 g of glass raw material mixture is indicated. It is important to write clearly. For example, when the requirements of the present invention are expressed in units of μg / g, the glass fiber manufacturing method of the present invention can spin molten glass from a heat resistant nozzle after passing through a plurality of melting stages having different holding temperatures in a glass melting container. In the first melting stage, the SO ₃ content in the glass raw material charged into the glass melting vessel is 500 μg (microgram) or more per 1 g of the glass raw material mixture. It is 3000 μg or less, that is, 500 μg / g or more and 3000 μg / g or less, and the maximum holding temperature in the melting stage after the second melting stage is higher than the maximum holding temperature in the first melting stage.

With the above configuration, the glass after passing through the first melting stage contains a sufficient amount of gas components resulting from SO ₃ in the glass raw material mixture charged in the first melting stage, When melted at a maximum holding temperature higher than that in the first melting stage after the melting stage, the volume of fine bubbles existing in the molten glass can be remarkably increased. And the remarkable increase of the volume of such a fine bubble arises, and it can raise rapidly on a molten glass surface, without leaving the bubble which remain | survives in a molten glass. Thus, since bubbles in the molten glass can be removed, the formation of hollow fibers can be suppressed even when formed as a fiber.

In the first melting stage, if the SO ₃ content in the glass raw material mixture put into the glass melting vessel is less than 0.05% by mass with respect to the total amount of the glass raw material mixture, the bubbles cannot be sufficiently removed. Therefore, it is not preferable. On the other hand, if the SO ₃ content in the glass raw material mixture put into the glass melting vessel exceeds 0.30% by mass with respect to the total amount of the glass raw material mixture, too much SO ₂ gas is generated during the primary melting. A so-called batch blowing phenomenon occurs, and there is a risk that raw materials and the like may be blown out and scattered from a container for melting glass, which is not preferable because the environmental treatment cost for not releasing SO ₃ into the atmosphere increases. Further, the amount of gas generated in the molten glass after the second stage is excessively increased. As a result, it may be rather easy to generate a hollow fiber, which is not preferable. The SO ₃ component in the glass raw material mixture contains, for example, alkaline earth metal elements in the glass raw materials, or sulfates and sulfides of alkali metal elements, such as CaSO ₄ , MgSO ₄ , and Na ₂ SO _4. The required amount of the present invention may be ensured by adjusting the content. In addition, the SO ₃ component content may be measured by employing a known chemical instrument analysis method such as ion chromatography analysis.

In addition, when the maximum holding temperature of the molten glass in the first melting stage is lower than 1350 ° C., the glass raw material mixture does not melt sufficiently in the glass melting container, and undissolved residue remains, and even after the second stage. Since it may remain unmelted and cause the fiber to be cut when spinning the glass fiber, it is not preferable. On the other hand, regarding the maximum holding temperature in the first melting stage, in the first melting stage, a large amount of gas derived from the SO ₃ component is generated in the molten glass, and after the second stage, the temperature is higher than that in the first stage. In order to prevent the diameter of fine bubbles generated in the molten glass from being increased sufficiently in the second and subsequent stages even if the molten glass is held, it is preferably set to 1500 ° C. or lower.

  In the glass fiber manufacturing method of the present invention, in addition to the above, the maximum holding temperature of the molten glass in the first melting stage is 1350 ° C. or higher, and the maximum holding temperature of the molten glass is the first in the melting stage after the second melting stage. If the temperature is higher than the maximum holding temperature of one melting stage, it becomes easy to remove bubbles in the molten glass in the melting stage immediately before molding the glass fiber, so that a more stable glass fiber is produced. This is preferable.

In the method for producing glass fiber of the present invention, after the second melting stage, the SO ₃ content in the glass raw material charged into the glass melting vessel is set to 0.003 mass than the SO ₃ content in the glass fiber. By increasing the amount of at least 5%, a gas corresponding to an SO ₃ content of 0.003% by mass or more is generated in the molten glass by maintaining the temperature of the molten glass at a higher temperature than before in the final melting stage. Therefore, it is preferable to defoam the fine bubbles in the molten glass, and the clarification proceeds.

The point that the SO ₃ content in the glass raw material charged into the glass melting container after the second melting stage is 0.003% by mass or more than the SO ₃ content in the glass fiber will be described below. To do. That is, this description shows the difference between the SO ₃ content in the glass put into the heat-resistant container and the SO ₃ content in the glass fiber when entering the second melting stage after the first melting stage. Limited. After the second melting stage, either cooled or solidified glass, that is, glass cullet may be charged, or molten glass may be charged. However, in order to manage the glass flow rate, production volume, and production type more strictly, once the molten glass is cooled and solidified to room temperature, a glass cullet is produced, and then this is again put into the glass melting apparatus. Is preferable.

Further, when expressed in terms of μg / g unit, the present invention, after the second melting stage, the SO ₃ content in the glass raw material charged into the glass melting container is determined from the SO ₃ content in the glass fiber. 30 μg / g or more, in other words, after the second melting stage, the SO ₃ content in the glass raw material in a glass mixed state put into the glass melting vessel, that is, in the glass raw material containing glass cullet This indicates that the amount is 30 μg or more per gram of glass to be introduced, compared to the SO ₃ content in the glass fiber. Here, the content of the glass cullet in the glass raw material after the second melting stage can be set to a content of 1% by mass or more and 100% by mass or less when the total mass of the glass raw material is 100.

In the first melting stage, the glass fiber production method of the present invention is expressed in terms of mass percentage in terms of oxides, and SiO ₂ 70.0 to 80.0%, Al ₂ O _{3 0 to} 2.0%, B ₂ O. _{3 15.0~21.0%, MgO 0~1.0%,} CaO 0~2.0%, Li 2 O 0~2.0%, Na 2 O 0~3.0%, K 2 O 0 _3.0%, the _{Li 2 O + Na 2 O +} K 2 O 2.0~5.0% of the glass raw material glass compositions containing composition is obtained mixture, as long as it is turned into the glass melt for the container, The effect of increasing the volume of fine bubbles in the molten glass brought about by the limited range of the SO ₃ content in the glass raw material mixture and the limited range of the maximum holding temperature in the first melting stage is more pronounced. This is preferable.

  In the case of the above configuration, when formed as glass fiber, in addition to electrical performance and strength performance suitable as glass fiber applied to a printed wiring board, a thin fiber diameter, that is, a fine count glass Even if the fiber is molded, the frequency of occurrence of hollow fibers can be further remarkably reduced, which is preferable.

In the first melting stage, SiO ₂ 70.0 to 80.0%, Al ₂ O _{3 0 to} 2.0%, B ₂ O ₃ 15.0 to 21.0% in terms of oxide-based mass percentage, _{MgO 0~1.0%, CaO 0~2.0%,} Li 2 O 0~2.0%, Na 2 O 0~3.0%, K 2 O 0~3.0%, Li 2 O + Na 2 When a glass raw material mixture from which a glass composition containing 2.0 to 5.0% of O + K ₂ O is obtained is put into a glass melting vessel, various measuring means such as chemical analysis and instrumental analysis are used. Thus, each element component constituting the glass is displayed in terms of mass% in terms of oxide, and the above-described SiO ₂ 70.0 to 80.0%, Al ₂ O _{3 0 to} 2.0%, B ₂ O ₃ 15.0-21.0%, MgO 0-1.0%, CaO 0-2.0%, Li ₂ O _{0~2.0%, Na 2 O 0~3.0%} , K 2 O 0~3.0%, is that _{Li 2 O + Na 2 O +} K 2 O 2.0~5.0% and expressed. The notation of Li ₂ O + Na ₂ O + K ₂ O means an added value of oxide display of each component.

The limited range of the glass composition to which the glass fiber manufacturing method of the present invention is applied will be described below. First, the SiO ₂ component forms a skeleton of the structure of a glass article, but in a glass melt, the higher the content, the more hindered the clarification of bubbles in the molten glass. Therefore, even in a proper range SO ₃ content, preferably 80 wt% or less. On the other hand, if the content of the SiO ₂ component is too low, the chemical durability required for printed wiring board applications will not be satisfied, so it is not preferable to make it less than 70% by mass.

The Al ₂ O ₃ component does not need to be added, but if added in a small amount during the glass composition, it suppresses the phase separation phenomenon of the glass and improves the water resistance. In some cases, it may cause melt segregation, and the upper limit is preferably 2% by mass from the viewpoint of suppressing the occurrence of defects due to undissolved butts.

The B ₂ O ₃ component has a function of lowering the melting temperature of the glass and assisting clarification according to the SO ₃ content. However, if the content is excessively large, it causes a phase separation phenomenon, and the produced glass fiber In some cases, the acid resistance may be lowered. From the above viewpoint, the B ₂ O ₃ component is preferably in the range of 15.0% by mass or more and 21.0% by mass or less.

  The MgO component has a function as an auxiliary agent in order to allow the dissolution to proceed smoothly together with other alkaline earth element components in the molten glass. However, if it is contained in a large amount, the dielectric constant increases, so that it is not suitable for use as a printed wiring board. It may also cause a phase separation phenomenon. From the above viewpoint, the MgO component is preferably 1.0% by mass or less.

  The CaO component functions as an auxiliary agent similar to the MgO component, but its allowable content is larger. It is preferable that a CaO component shall be 2.0 mass% or less.

The Li ₂ O component has a remarkable effect as a flux that lowers the melting temperature at the time of glass melting, but in the case of glass fibers used for printed wiring boards, if the content is increased, in terms of chemical durability, etc. There may be a problem. From the above viewpoint, it is preferably 2.0% by mass or less.

The Na ₂ O component and the K ₂ O component also work in the same manner in the Li ₂ O component and the molten glass, but are components having a larger content rate tolerance. For this reason, it is preferable to set it as 3.0 mass% or less.

Further, regarding Li ₂ O + Na ₂ O + K ₂ O, that is, an increase in the added value of these three alkali metal oxide components, the addition of these components makes it possible to efficiently clarify the proper SO ₃ content in the glass. It is preferable because it acts effectively. On the other hand, it is preferable to limit the content of each component because of the limitation of use as a printed wiring board as described above. From the above viewpoint, it is preferable that Li ₂ O + Na ₂ O + K ₂ O be in the range of 2.0 mass% or more and 5.0 mass% or less.

If the SO ₃ content in the glass composition is within the range of 0.001% by mass or more and 0.02% by mass or less in the first melting stage, the glass fiber production method of the present invention is the second melting stage. Thereafter, by heating at a predetermined temperature condition higher than that described above in the molten glass, an optimal amount of SO ₂ gas is generated, and fine undefoamed bubbles present in the molten glass, It is possible to quickly release entrained bubbles or the like generated in the glass at the time of melting after the second stage from the molten glass.

When expressed in terms of μg / g, the above requirement is that the SO ₃ content in the glass composition after the first melting stage is 10 μg / g or more and 200 μg / g or less. In other words, the SO ₃ content in the glass composition after the first melting stage is 10 μg or more and 200 μg or less per 1 g of the glass raw material mixture.

In the first melting stage, if the SO ₃ content in the glass composition is less than 0.001% by mass, in the case of the molten glass having a viscosity of 10 ³ dPa · s of 1000 ° C. or more, the second melting stage and later It is not preferable because sufficient clarification may not be expected. On the other hand, in the first melting stage, even if the SO ₃ content in the glass composition exceeds 0.02% by mass, the clarification as much as that content is not exhibited, and the surroundings of the melting environment This is not preferable because problems such as adhesion of sulfides are increased, which may cause problems in molding.

The method for producing glass fiber of the present invention is a method of pulverizing and classifying the glass solidified product after the first melting stage and obtaining 1 g of glass powder having a particle size of 300 μm or more and 1000 μm or less from 800 ° C. to 1600 ° C. And heated in a 50 ml / min helium carrier gas at a heating rate of 8 ° C./min, and the amount of SO ₂ released during the heating time is 2.0 μg / l (liter) to 20 μg / l If it is within the range, an optimal amount of SO ₂ gas is generated after the second melting stage, and fine bubbles present in the molten glass and bubbles entrained in the glass after the second melting stage are also present. This is preferable because it can be quickly released from the molten glass. The glass powder having a particle size of 300 μm or more and 1000 μm or less passes through a sieve having an opening of 1000 μm, and the glass powder remaining on the sieve having an opening of 300 μm is collected, washed with ion-exchanged water to remove the fine powder, and then dried. Can be obtained. Here, the vitrified body is a solidified product that has been cooled to such an extent that it does not soften and deform.

The glass powder after primary melting having a particle size of 300 μm or more and 1000 μm or less obtained by pulverizing and classifying the vitrified glass after the first melting stage is heated at 8 ° C./min from 800 ° C. to 1600 ° C. When heated in a helium carrier gas at a temperature rate of 50 ml / min and the amount of SO ₂ released during the temperature rising time is less than 2.0 μg / l (liter), a temperature range of 800 ° C. to 1600 ° C. That is, since the molten glass cannot be sufficiently released in the temperature range where the molten glass is exposed during a period of time in which the molten glass stays in the glass melting container for clarification, the fine bubble diameter distribution is reduced. If a large number of residual bubbles remain, it may not be possible to achieve sufficient defoaming, which is not preferable. On the other hand, if the amount of SO ₂ released under the same conditions exceeds 20 μg / l, the amount of gas generated becomes too large, and it takes a long time for clarification after the second melting stage. In order to cope with it, the molten glass must be exposed to a higher temperature than necessary, which is not preferable from the viewpoint of energy saving.

  The glass fiber of the present invention is produced by the glass fiber production method of the present invention, and has an average fiber diameter of more than 3.0 μm and less than 9.0 μm.

It is manufactured by the manufacturing method of the glass fiber of this invention, and it is the following structures that an average fiber diameter exceeds 3.0 micrometers and is less than 9.0 micrometers. That is, a glass fiber manufacturing method for spinning molten glass from a heat-resistant nozzle after passing through a plurality of melting stages having different holding temperatures in a glass melting container, and in the first melting stage, into the glass melting container The SO ₃ content in the glass raw material mixture to be charged is 0.05% by mass to 0.30% by mass with respect to the total amount of the glass raw material mixture, and the maximum holding temperature of the molten glass in the first melting stage is It is 1350 ° C. or higher, and the temperature is controlled so that the maximum holding temperature in the melting stage after the second melting stage is higher than the maximum holding temperature in the first melting stage. To do. In the present invention, the glass fiber thus obtained has an average equivalent circle diameter of all the glass filaments constituting the strands larger than 3.0 μm and thinner than 9.0 μm. To measure the average equivalent circle diameter, measure the cross-sectional diameter of all glass filaments drawn continuously from the heat-resistant nozzle to one decimal place using a calibrated measuring device, and round off the average value. It was obtained.

  Even if the average fiber diameter of the glass fiber is less than 3.0 μm, it is possible to manufacture if there is no need for labor for manufacturing, management and maintenance of a high-precision nozzle required for manufacturing, The most efficient production is possible when the average fiber diameter exceeds 3.0 μm. On the other hand, an average fiber diameter exceeding 9.0 μm is not preferable because the cloth becomes thick when used for a printed board, and a high-density printed board cannot be obtained. From the above viewpoints, if limited to high-density printed wiring board applications, the average fiber diameter of the glass fibers is preferably larger than 3.0 μm, 7.5 μm or less, more preferably larger than 3.5 μm. , 6.0 μm or less.

  If the glass fiber of the present invention is a glass yarn used for a printed wiring board, when used for a printed wiring board, it is made of glass fiber having a uniform and high quality when drilling or laser processing is performed. Since it is configured, the drilling position does not deviate from the desired position, and it is easy to perform high-precision processing on the substrate.

  A glass yarn is formed by twisting strands formed by attaching a sizing agent to 50 to 800 glass filaments and bundling them, and the average value of the fiber diameters of all the filaments constituting the strand is 3.0 μm. More than 9.0 μm.

  As for the yarn, as long as a predetermined twist is imparted, the size and direction of the twist including the non-twisted yarn are not particularly limited.

  The glass fiber of the present invention can be given various performances by applying various surface treatment agents. For example, sizing agent, binding agent, coupling agent, lubricant, antistatic agent, emulsifier, emulsion stabilizer, pH adjuster, antifoaming agent, antifungal agent or stabilizer, etc., alone or in any combination Then, an appropriate amount can be applied and coated on the surface of the glass fiber. Further, such a surface treatment agent or coating agent may be a starch type or a plastic type.

  For example, acrylic, epoxy, urethane, polyester, vinyl acetate, vinyl acetate / ethylene copolymer, or the like can be used as appropriate as long as it is plastic.

  Moreover, the glass fiber of this invention can use various chemical | medical agents individually or in combination as above-mentioned as a sizing agent used for focusing of a glass filament. Of these, starch is most often used in the case of glass yarn. Starch focuses glass filaments, and as a film-forming agent on the surface of glass fiber, the surface of glass yarn due to bending and friction during the process. It is used for the purpose of protecting.

In addition, the glass fiber of the present invention is preferably a product of dielectric constant ε and dielectric loss tangent tan δ of 9 × 10 ⁻³ or less because when used in a printed wiring board, dielectric loss is suppressed to a small level.

Here, the dielectric constant ε is a dimensionless number that means a relative dielectric constant that is a ratio of a dielectric constant of a medium and a dielectric constant of a vacuum, and is a dielectric constant at a frequency of 1 MHz at room temperature. When the product of the dielectric constant ε and the dielectric loss tangent tan δ is 9 × 10 ⁻³ or less, the dielectric loss energy W absorbed by the glass as energy by absorbing the alternating current when the alternating current flows through the glass is small. Therefore, it is preferable. Here, the dielectric loss energy W is represented by W = kfv ² × εtanδ. Here, W is a dielectric loss energy, k is a constant, f is a frequency, v ² is a potential gradient, ε is a dielectric constant, and tan δ is a dielectric loss tangent. Since the transmission loss decreases as the dielectric loss energy W decreases, the product of the dielectric constant ε and the dielectric loss tangent tan δ is more preferably 8 × 10 ⁻³ or less, and further preferably 7 × 10 ³ from this viewpoint. ^-3 or less.

  Moreover, although the preferable use of the glass fiber of this invention is a printed wiring board, you may use it for another electronic component use. Specifically, it can be used for the following purposes. For example, an insulating plate, a terminal plate, an IC substrate, a display substrate, an electronic device housing material, an optical component package, an electronic component package, or an insulating support. Further, the glass fiber of the present invention can be used alone.

(1) The glass fiber manufacturing method of the present invention is a glass fiber manufacturing method in which molten glass is spun from a nozzle after passing through a plurality of melting stages having different holding temperatures in a glass melting container. In the step, the SO ₃ content in the glass raw material mixture charged into the glass melting vessel is 0.05% by mass or more and 0.30% by mass or less with respect to the total amount of the glass raw material mixture. When the glass is melted, the maximum holding temperature of the molten glass at 1350 ° C. is higher than the maximum holding temperature in the melting stage after the second melting stage and higher than the maximum holding temperature in the first melting stage. Suppressing the remaining bubbles, resulting in the removal of bubbles mixed in the glass fiber, and realizing a high yield rate, dramatically improving the glass fiber production efficiency, that is, the production yield. Can be raised.

(2) In the glass fiber production method of the present invention, after the second melting stage, the SO ₃ content in the glass raw material charged into the glass melting container is 30 μg more than the SO ₃ content in the glass fiber. If the amount is more than / g, a sufficient amount of gas is generated after the second melting stage, which greatly contributes to the expansion of the bubble diameter in the molten glass, and clarification is smoothly promoted. preferable.

Process for producing a glass fiber (3) According to the present invention, in the first melting step, as represented by mass percentage terms of _{oxides, SiO 2 70.0~80.0%, Al 2} O 3 0~2.0% _{, B 2 O 3 15.0~21.0%,} MgO 0~1.0%, CaO 0~2.0%, Li 2 O 0~2.0%, Na 2 O 0~3.0%, K ₂ O 0 to _3.0%, the _{Li 2 O + Na 2 O +} K 2 O 2.0~5.0% of the glass containing the composition composition glass raw material mixture obtained, which turned into a glass melting for container If so, the glass fiber produced in the glass production process in the second and subsequent stages is significantly reduced in hollow fiber and becomes a glass fiber having a low dielectric constant.

Process for producing a glass fiber (4) The present invention, if in the first melting step, the SO ₃ content of the glass composition in the range of 0.001 wt% 0.02 wt% or less, the It is preferable because the glass fiber can be produced in a state having a sufficient SO ₃ content to remove bubbles in the glass generated in various stages after the single melting stage.

(5) Moreover, the manufacturing method of the glass fiber of this invention is a glass powder of the mass 1g which has a particle size of 300 micrometers or more and 1000 micrometers or less obtained by grind | pulverizing and classifying the glass solidified body after a 1st fusion | melting stage. To 50 ° C. and heated in a helium carrier gas at a rate of 8 ° C./min, and the amount of SO ₂ released during the temperature rising time is 2.0 μg / l (liter) or more to 20 μg / min. If it is within the range of l or less, the fine bubbles present in the molten glass and the entrained bubbles of the material glass (cullet) at the time of remelting can be quickly and completely removed, and the bubbles are eliminated. This makes it possible to produce high quality fine glass fibers.

  (6) The glass fiber of the present invention is produced by the method for producing glass fiber of the present invention, and has an average fiber diameter of more than 3.0 μm and less than 9.0 μm. For example, it is possible to provide customers with high-quality glass fibers that do not contain bubbles with the optimal fiber diameter.

  (7) If the glass fiber of this invention is used for the wiring board for electronic components, a highly reliable printed circuit board with a low dielectric constant, etc. can be manufactured easily.

It is explanatory drawing which shows the heat history at the time of glass melting in the manufacturing method of the glass fiber which concerns on this invention. It is explanatory drawing which shows the heat history at the time of glass melting in the manufacturing method of the other glass fiber which concerns on this invention.

  Below, the manufacturing method of the glass fiber of this invention and the glass fiber obtained by this manufacturing method are demonstrated concretely based on an Example.

  The present invention relates to a manufacturing method for obtaining glass fibers in a multi-stage melting stage. In Example 1, a case where two stages of a first melting stage and a second melting stage are performed will be described. Table 1 shows the glass composition of the glass fiber according to Example 1 of the present invention, the measurement results of the first melting stage, and the second melting stage. The glass composition in oxide conversion notation shown in the table is expressed in mass%.

  As Example 1 of the present invention, Sample No. 1 to sample no. About each glass sample of 5, the sample was prepared in the procedure shown below and evaluation of the glass fiber finally obtained was implemented.

First, a predetermined amount of a plurality of glass raw materials such as natural raw materials and chemical raw materials are weighed so as to have each glass composition, and a glass raw material mixed batch prepared in advance so as to be in a homogeneous state is placed in a platinum rhodium crucible. throw into. By the way, in order to contain an appropriate amount of SO ₃ content in the glass raw material mixture put into the platinum rhodium crucible, mirabilite (Na ₂ SO ₄ · 10H ₂ O), also called Grauber salt, is contained in the glass raw material mixing batch. A predetermined amount was added. Below, the manufacturing method of glass fiber is demonstrated, referring the temperature history of the molten glass shown in FIG.

  The raw material mixture batch put into the platinum rhodium crucible was heated in the atmosphere using an indirect heating electric furnace for 5 hours at each maximum holding temperature A described in Table 1 as the first melting stage, The mixed batch was subjected to high temperature chemical reaction to obtain molten glass. In addition, in order to make a molten glass into a homogeneous state, the molten glass was stirred using a heat-resistant stirring rod in the middle of heating and melting. In addition, the maximum holding temperature of each molten glass was measured with the thermocouple.

  In order to rapidly cool the molten glass in a homogeneous state in this way, roll forming was performed to obtain a film-like glass having a thickness of 1 mm. This film-like glass was pulverized with a ball mill to a particle size that passed through a sieve having an opening of 5 mm to obtain a glass material (glass cullet) at room temperature.

The composition of the glass material was obtained by analyzing a sample having a known composition value using a fluorescent X-ray analyzer as a standard. The analysis value of the SO ₃ component is a value obtained by an instrumental analyzer such as ion chromatograph analysis.

  This glass material is continuously charged again into a heat-resistant melting container (not shown) of a spinning device equipped with a heating device, and the glass material is kept in a container that maintains the temperature so that the maximum holding temperature B shown in Table 1 is reached. Two melting steps were performed. In the second melting stage, the molten glass is drawn out continuously from 200 heat resistant nozzles provided on the bottom surface of the heat resistant container in a state where bubbles are released from the molten glass and single fiber. A glass fiber having a diameter of 7 μm was spun.

  The number of bubbles in the glass was measured by interrupting the spinning of the glass fiber and collecting the bead-like glass dropped from the nozzle. Specifically, by immersing about 100 g of bead-like glass in benzyl alcohol and observing with a 10 × microscope in a state where measurement of bubbles is prevented by a difference in refractive index from the atmosphere, The number of bubbles contained therein was measured and converted to the number of bubbles contained per 100 g of glass.

By the above test, test No. which is an example of the present invention. 1 to test no. Samples up to 5 were SiO ₂ 74.6-75.6%, Al ₂ O ₃ 0.2-1.0%, B ₂ O ₃ 19 in weight percent of the glass composition obtained by the first melting stage. 0.5 to 20.5%, MgO 0.3 to 0.5%, CaO 0.4 to 0.6%, Li ₂ O + Na ₂ O + K ₂ O within the range of 3.3 to 3.5%, _SiO 2 from 70.0 to _80.0% is a requirement of the _{invention, Al 2 O 3 0~2.0%,} B 2 O 3 15.0~21.0%, MgO 0~1.0%, CaO 0 _{~2.0%, Li 2 O 0~2.0%} , Na 2 O 0~3.0%, K 2 O 0~3.0%, Li 2 O + Na 2 O + K 2 O 2.0~5.0 % Is within the range. In addition, Test No. 1 to test no. The SO ₃ content in the glass raw material mixture up to 5 is 0.12 to 0.16% by mass, and satisfies the requirement of 0.05% by mass to 0.30% by mass which is a requirement of the present invention. Yes. The maximum holding temperature in the first melting stage is 1450 ° C. or more and 1495 ° C. or less, and the maximum holding temperature in the second melting stage is 1515 ° C. to 1550 ° C. higher than the maximum holding temperature in the first melting stage of each sample. Since it is within the range, this also satisfies the requirements of the present invention.

In addition, test No. obtained by the first melting stage. 1 to test no. When the SO ₃ content in the material glass No. 5 is analyzed, the value is 0.005 to 0.008% by mass, and the SO ₃ content that is the invention requirement of the present invention is 0.001% by mass or more and 0.0. It is within the range of the condition of 02% by mass or less. This test No. 1 to test no. In other words, the analysis results of 5 are converted, in other words, in the range of 50 to 80 μg / g and the SO ₃ content is in the range of 10 μg / g or more and 200 μg / g or less.

Furthermore, test No. obtained by the first melting stage. 1 to test no. In order to measure the amount of dissolved SO ₂ gas contained in the material glass No. 5, the following evaluation was performed. First, the material glass is pulverized to produce a powder having a particle size of 300 μm or more and 1000 μm or less. Next, this powder is filled in a heat-resistant sample holder of a quadrupole mass spectrometer and put into an electric furnace. The temperature of the electric furnace is increased while flowing He gas as a carrier gas at 50 ml / min in the electric furnace. At this time, the SO ₂ gas generated from 800 ° C. to 1600 ° C. is introduced to the quadrupole mass spectrometer. In this way, the amount of SO ₂ gas is measured. As a result of measurement under the above conditions, the test No. obtained in the first melting stage was obtained. 1 to test no. The amount of dissolved SO ₂ gas contained in the material glass No. 5 is 6.1 to 10.2 μg / l (liter), and is within the range of 2.0 μg / l (liter) to 20 μg / l. It was.

  The number of bubbles in the sample after the second melting stage, that is, the sample melted until spinning was 2/100 g or less, which was sufficiently low. For this reason, it was confirmed that when glass fibers were produced by spinning, the quality was such that the number of hollow fibers generated could be reduced.

Moreover, test No. which is an Example. 1 to test no. All of the samples up to 5 have a product suitable for a material used for a printed wiring board because the product of the dielectric constant ε and the dielectric loss tangent tan δ, that is, the value of ε × tan δ is 6 × 10 ⁻³ or less. . Incidentally, the dielectric constant ε and the dielectric loss tangent tan δ were measured by polishing both surfaces with a thickness of 3 mm of glass sample pieces processed to dimensions of 50 mm × 50 mm × 3 mm with # 1200 sandpaper. The measurement was based on ASTM D150-87, and was obtained by measuring at a frequency of 1 MHz at room temperature by using a 4192A impedance analyzer manufactured by Yokogawa Hewlett-Packard.

  A particularly characteristic sample in Example 1 of the present invention will be described below.

Sample No. 1 of Example 1 1 of the glass composition, SO ₃ content of 0.16 wt%, i.e., the SO ₃ content of the glass in the raw material per unit g [mu] g (microgram) expressed, SO ₃ content is 1600μg / g A glass raw material mixed batch was melted at a maximum holding temperature of 1470 ° C. for 5 hours as a first melting stage. About this sample, the SO ₃ content in the first melting stage is 0.008% by mass, that is, the SO ₃ content in the glass raw material per unit g is expressed in μg, and the SO ₃ content is 80 μg / g. A glass material having a dissolved SO ₂ amount of 10.2 μg / l (liter) was obtained. Next, this glass material was melted at a maximum holding temperature of 1520 ° C. as a second melting stage, and glass fibers were spun. The number of bubbles in the glass thus obtained was 0 per 100 g of glass, and no defects were observed.

Sample No. 1 of Example 1 2 of the glass composition, SO ₃ content of 0.14 wt%, i.e., the SO ₃ content of the glass in the raw material per unit g and [mu] g (microgram) notation, SO ₃ content of 1400Myug / g, In other words, a glass raw material mixed batch of 1400 ppm per 100 g of glass raw material is melted at the maximum holding temperature of 1485 ° C. for 5 hours as the first melting stage. For this sample, the SO ₃ content is 0.007% by mass, that is, the SO ₃ content in the glass raw material per unit g is expressed in μg, and the SO ₃ content is 70 μg / g (or SO ₃ per 100 g of glass raw material). A glass material having a content of 70 ppm and a dissolved SO ₂ content of 7.9 μg / l (liter) was obtained. Next, this glass material was melted at a maximum holding temperature of 1535 ° C. as a second melting stage, and glass fibers were spun. The number of bubbles in the glass thus obtained was 1 per 100 g of glass, which was a sufficiently small value. In addition, the SO ₃ content in the obtained glass fiber was analyzed to be 0.0012% by mass, that is, 12 μg per 1 g of glass, in other words, 12 ppm. That is, this fact is that the SO ₃ content in the glass raw material charged into the glass melting container after the second melting stage is 0.003 mass% or more than the SO ₃ content in the glass fiber. Satisfies the requirements.

Sample No. 1 in Example 1 The glass composition of No. ₃ has an SO ₃ content of 0.15% by mass, that is, a glass material mixed batch with 1500 μg / g (or SO ₃ content per 100 g of glass raw material of 1500 ppm) as a first melting stage and a maximum holding temperature. And melted at 1495 ° C. Thus, the SO ₃ content is 0.006 mass%, that is, the SO ₃ content in the glass raw material per unit g is expressed in μg, and the SO ₃ content is 60 μg / g (or the SO ₃ content per 100 g of the glass raw material. 60 ppm), and a glass material having a dissolved SO ₂ content of 7.2 μg / l was obtained, then melted at a maximum holding temperature of 1550 ° C. as a second melting stage, and glass fibers were spun. The number of bubbles in this glass was 2 and was sufficiently small per 100 g of glass.

  Next, as a comparative example, Sample No. 101 and sample no. As shown in Table 1, the glass according to 102 was also evaluated in the same procedure as in the example of the present invention, and a series of evaluations were performed. The results are shown below.

Sample No. of Comparative Example Glass composition of 101, SO ₃ content of 0.15% by mass, that is, melted at 1550 ° C. as the maximum holding temperature glass raw materials mixed batch of 1500 [mu] g / g as a first melting step, SO ₃ content of 0. A glass material having 0005% and a dissolved SO ₂ content of 1.9 μg / l was obtained. Next, the second melting stage is melted at a maximum holding temperature of 1520 ° C., which is lower than the first melting stage, and the SO ₃ content after the first melting stage is 0.0005% and the dissolved SO ₂ quantity is The number of bubbles in this glass was as small as 1.9 μg / l, and there were as many as 20 bubbles per 100 g of glass.

Sample No. of Comparative Example The glass composition of No. 102 has an SO ₃ content of 0.02% by mass, that is, a glass raw material mixed batch of 200 μg / g is melted at 1490 ° C. as the maximum holding temperature as the first melting stage, and the SO ₃ content is 0.00. A glass material having a 0003% or less dissolved SO ₂ amount of 0.3 μg / l was obtained. And after that, it melted at 1530 ° C. as the maximum holding temperature as the second melting stage higher than the primary melting, but the SO ₃ content was 0.0003% or less and the dissolved SO ₂ amount was very small as 0.3 μg / l. The number of bubbles in this glass was 100, which is 100 bubbles per 100 g of glass.

  As Example 2 according to the glass fiber manufacturing method of the present invention, unlike Example 1, it is not cooled to room temperature after the first melting stage, and after passing through the second melting stage, it is not cooled to room temperature. An example in which spinning is performed as a glass fiber after reaching the melting stage and passing through a total of three melting stages is shown below with reference to FIG.

  A glass raw material mixing batch having the same glass composition as described in Example 1 of the present invention was prepared, and this raw material was charged into a melting tank in a continuous melting type glass melting furnace using a screw feeder. The glass raw material mixture batch that has been charged rises to 1450 ° C. as the maximum holding temperature A in the first melting stage and then temporarily decreases to 1400 ° C.

When the molten glass is sampled at the end of the first melting stage and the SO ₃ content in the glass is analyzed in the same manner as in Example 1, the value is 0.007% by mass, that is, 70 μg / g. The heating in the same heating schedule as Example 1 contained in the molten glass, when the generated SO ₂ gas measured by the same analytical methods, that value is 10.0 [mu] g / l, the requirements of both the present invention I was satisfied.

  Next, the molten glass is heated to 1430 ° C. as the second melting stage in the heating zone from the melting tank to the clarification tank, and then drops again to 1400 ° C. near the entrance of the clarification tank. Thereafter, the molten glass enters the third melting stage in the clarification tank. In the third melting stage, the molten glass is heated to a maximum holding temperature of 1550 ° C., enters the forming zone, and flows into the bushing. Thereafter, the molten glass is drawn out from a nozzle attached to the bushing, applied with a sizing agent by an applicator, and wound up by a winder as a glass yarn cake. The glass yarn having the optimum quality for the printed wiring board thus obtained has a much lower incidence of hollow fibers than the conventional one, and has a stable production quality.

  In Example 3, each raw material was prepared in the same procedure as in Example 1 so as to have the same glass composition as in Example 1. Next, test no. 1 to test no. A predetermined amount of each of the five raw materials was put into a heat-resistant container in an experimental small glass melting furnace. The charged raw material was heated to the maximum holding temperature A in the first melting stage of Example 1. Next, a program is used to raise the maximum temperature range of the second melting stage from the maximum holding temperature A of the first melting stage so that the holding temperature is stepped in steps of 10 ° C or 15 ° C. It was set as the molten glass by the temperature rising schedule which hold | maintains for 20 minutes. And in Example 3, after such a temperature rising and holding schedule, it was hold | maintained so that it might become the same temperature as the maximum holding temperature B of the 2nd melting stage of Example 1 in the final melting stage after a 2nd melting stage. It was set as the manufacturing process spun later. Even in the case of having such a multi-stage holding temperature, it was confirmed that the requirements of the present invention were satisfied when verified in the same manner as described above.

As explained above, according to the method for producing glass fiber of the present invention, glass fiber having an extremely low occurrence frequency of hollow fiber can be obtained, and the optimum performance when used for printed wiring is demonstrated. It became clear that it would be.

Claims (7)

A glass fiber manufacturing method for spinning molten glass from a nozzle after passing through a plurality of melting stages having different holding temperatures in a glass melting container,
In the first melting stage, the SO ₃ content in the glass raw material mixture charged into the glass melting vessel is 0.05% by mass to 0.30% by mass with respect to the total amount of the glass raw material mixture,
The maximum holding temperature of the molten glass in the first melting stage is 1350 ° C. or higher, and the maximum holding temperature in the melting stage after the second melting stage is higher than the maximum holding temperature in the first melting stage. A method for manufacturing glass fiber. The SO ₃ content in the glass raw material charged into the glass melting container after the second melting stage is increased by 0.003 mass% or more than the SO ₃ content in the glass fiber. 2. A method for producing a glass fiber according to 1. In the first melting stage, SiO ₂ 70.0 to 80.0%, Al ₂ O _{3 0 to} 2.0%, B ₂ O ₃ 15.0 to 21.0% in terms of oxide-based mass percentage, _{MgO 0~1.0%, CaO 0~2.0%,} Li 2 O 0~2.0%, Na 2 O 0~3.0%, K 2 O 0~3.0%, Li 2 O + Na 2 the O + K ₂ O 2.0~5.0% of the glass raw material glass compositions containing composition is obtained mixture, according to claim 1 or claim 2, characterized in that introduced into the glass melt for the container Manufacturing method of glass fiber. The SO ₃ content in the glass composition is controlled to be in the range of 0.001% by mass or more and 0.02% by mass or less in the first melting stage. Glass fiber manufacturing method. A glass powder having a particle size of 300 μm or more and 1000 μm or less obtained by pulverizing and classifying the glass solidified product after the first melting stage is heated at a rate of 8 ° C./min from 800 ° C. to 1600 ° C. Heating in a helium carrier gas of 50 ml / min, the amount of SO ₂ released during the temperature rising time is set within a range of 2.0 μg / l (liter) to 20 μg / l. The manufacturing method of the glass fiber in any one of Claims 1-4.   A glass fiber produced by the method for producing glass fiber according to any one of claims 1 to 5, having an average fiber diameter of more than 3.0 µm and less than 9.0 µm. It is used for the wiring board for electronic components, The glass fiber of Claim 6 characterized by the above-mentioned.