JP4117619B2 - Glass fiber nonwoven fabric and printed wiring board - Google Patents

Description

The present invention relates to a glass fiber nonwoven fabric suitable for use as a material for insulating reinforcement of a glass fiber reinforced laminate such as a double-sided copper foil-coated double-sided printed wiring board and a multilayer printed wiring board, and also uses the glass fiber nonwoven fabric. The present invention relates to a printed wiring board.
Moreover, this invention relates to the high flat glass fiber used for manufacture of a glass nonwoven fabric etc., the nozzle chip for high flat glass fiber spinning, the nozzle chip arrangement | positioning method, and a glass fiber manufacturing apparatus.

Conventionally, a glass cloth has been widely used as a material for reinforcing insulation of a printed wiring board, and a glass fiber nonwoven fabric (also referred to as glass paper) is used in part. For example, in the field of low-priced products, a printed wiring board with a double-sided copper foil called composite CEM-3 using a glass fiber nonwoven fabric as a core and glass cloth on both sides is used. The glass fiber non-woven fabric used here is obtained by dispersing glass fibers having a circular cross section with a diameter of 3 to 10 μm and a length of about 3 to 25 mm in water and making a paper with a paper machine. ˜700 μm and the basis weight is about 25 to 100 g / m ² .
However, since the conventional glass fiber nonwoven fabric has a low bulk density, the printed wiring board using the glass fiber nonwoven fabric increases the amount of resin contained in the wiring board, and the entire surface and core material layers are composed of glass cloth. Compared with the printed glass / epoxy resin printed wiring board, there is a problem that the thermal expansion coefficient of the core part is large and the reliability of the through-hole plating part is inferior.

In addition, since the conventional glass fiber nonwoven fabric is made of a glass fiber having a circular cross section, there is almost no entanglement between the fibers, and therefore a large amount of binder (for example, to give the tensile strength necessary for the glass fiber nonwoven fabric) 10 to 13% by weight). However, the surfactant contained in the emulsion-type adhesive used as a binder has the property of reducing the bonding force between the glass fiber surface and the matrix resin, so when the binder content increases, There is also a problem that the bond strength with the matrix resin is greatly reduced, the hot water resistance and heat resistance are deteriorated, and the insulation resistance after the pressure cooker test is deteriorated.
Furthermore, in general, in the process of producing a prepreg, the solvent in the resin is removed, the volume of the resin part decreases, and the so-called sink phenomenon occurs in which the resin moves from the surface to the inside. The volume shrinkage of the resin occurs after pressurizing and hot pressing. If a prepreg is produced using a glass fiber nonwoven fabric on the surface and a copper foil is applied to the surface and press molded, the bulk of the glass fiber nonwoven fabric is obtained. Since the density is low and the amount of resin is large, the phenomenon of sink marks is large, and the volumetric shrinkage of the resin is also large. For this reason, an unevenness of nearly 10 μm is generated on the resin surface of the manufactured laminated board, and the same unevenness is also generated on the copper foil pasted thereon, and the circuit is formed by partially removing the copper foil by etching or the like. When this is done, the copper foil in the concave portion is likely to remain (hard to remove), and the copper foil in the convex portion is likely to be removed, so that a fine circuit is disconnected or erroneously connected by the remaining copper foil. Moreover, since adhesion of copper foil can be uneven, problems such as similar disconnection occur. For this reason, the conventional glass fiber nonwoven fabric cannot be used for the surface which affixes copper foil.

Thus, the conventional glass fiber nonwoven fabric is inferior in characteristics when used for a printed wiring board compared to a glass cloth, and cannot be used on the surface, so it is used as an intermediate layer of a printed wiring board with double-sided copper foil. I had to use it.
Therefore, an attempt to improve the properties of the conventional glass fiber nonwoven fabric and use it for a printed wiring board instead of a glass cloth was performed using glass fibers having an irregular cross section, Patent Document 1, Patent Document 2, It is proposed in Patent Document 3 and the like. In these patent documents, glass fiber nonwoven fabrics made using flat glass fibers having a flat cross-sectional shape such as an elliptical shape, an eyebrows shape, and a capsule shape are proposed, and these may increase the bulk density. In addition, it is described that the tensile strength can be increased. Patent Document 2 also describes that the amount of the binder can be reduced (up to about 3% by weight) by using glass fibers having a flat cross section.
Certainly, it is possible to increase the bulk density of the nonwoven fabric to some extent by using the glass fiber having a flat cross-sectional shape, and the unevenness of the surface when the glass fiber nonwoven fabric is used on the surface of the laminate is about 4 μm. It is possible to make it as small as possible. However, the glass fiber nonwoven fabric used in place of the glass cloth is desired to have further improved properties, particularly high content and improved surface smoothness.

For example, in recent years, electronic devices have been used in which a plurality of circuit boards called multilayer boards (or multilayer printed wiring boards) are laminated due to miniaturization and high performance of electronic devices. It is desired to narrow the width of the frame and arrange it without gaps. In order to answer such a demand, it is desirable to make the copper foil as thin as possible (for example, about 12 μm or less). However, if the copper foil is made thin, the influence of the surface unevenness of the laminated board to which the copper foil is attached is increased. Therefore, it is required to further improve the surface smoothness of the laminate. However, even with a laminated sheet using a conventional glass cloth, the surface smoothness is limited to about 3 μm, and no more smoothness can be obtained. From this point, there is a limit to reducing the thickness of the copper foil. . Therefore, development of a reinforcing material capable of improving the surface smoothness of the laminated plate is more desired than when glass cloth is used, and development of a glass fiber nonwoven fabric that satisfies the demand has been desired.
Moreover, when using a glass fiber nonwoven fabric for a multilayer printed wiring board, it is desirable that the glass fiber nonwoven fabric is as thin as possible, and a basis weight of about 15 to 40 g / m ² is required. In the nonwoven fabric, there is also a problem that the amount of the binder cannot be reduced so as to ensure the necessary strength. For example, in Patent Document 2 described above, it is described that the amount of the binder can be 3% by weight, but this is a case where the thickness of the non-woven fabric is thick, and the inventors have made additional trials. As shown in Comparative Examples 1 and 2 to be described later, when the basis weight is 20 g / m ² , the prepreg cannot be produced when the binder amount is 6% by weight, and 10% is required to ensure the strength necessary for prepreg production. % Was required.
Japanese Patent Publication No.7-122235 JP-A-6-257042 JP-A-8-127994

The present invention has been made on the basis of such a demand, and is a glass fiber nonwoven fabric having a required strength even when the bulk density of the nonwoven fabric is increased and the binder amount is decreased, and is a laminated board using this as a reinforcing material To provide a thin glass fiber nonwoven fabric capable of increasing the glass fiber content and improving the surface smoothness, and to provide a printed circuit board comprising a laminate using the glass fiber nonwoven fabric as a reinforcing material. Objective.
In the present invention, the longest diameter of the cross section of the flat glass fiber / the flatness ratio represented by the longest short diameter perpendicular to the longest diameter is 2.0 to 10, and the rectangular area circumscribing the cross section of the flat glass fiber An object of the present invention is to provide a high flat glass fiber having a ratio of the cross-sectional area of the flat glass fiber to that of 85% or more, preferably 90 to 98%.
A further object of the present invention is to provide a glass fiber spinning nozzle tip capable of producing the above flat glass fiber with stable quality and high productivity, and a nozzle tip arrangement method therefor.

As a result of various studies on the cross-sectional shape of the glass fiber used for the glass fiber nonwoven fabric in order to achieve the above object, the inventors of the present invention are highly flat glass fibers having a flat cross section, and the flatness ratio of the cross section is 2.0 to 10 and preferably 3.1 to 8 and a filling ratio of 85% or more, preferably 90% or more, more preferably 93 to 98%, by a papermaking method using a high flat glass fiber. When producing a nonwoven fabric, most of the flat glass fibers overlap with the flat surface down, the contact area between the flat glass fibers overlapped increases, and the binder is made very small such as about 3 to 8% by weight, A thin nonwoven fabric with the strength required for handling can be produced, and the resulting nonwoven fabric has a high bulk density and the surface smoothness of the laminate made from the nonwoven fabric is extremely good. It found that, and have completed the present invention.
That is, the glass fiber forming the glass fiber nonwoven fabric in the present invention is a highly flat glass fiber having a flat cross section (hereinafter sometimes simply referred to as “flat glass fiber”), and the flat ratio of the cross section However, it is 2.0-10, Preferably it is 3.1-8, Moreover, the filling rate is 85% or more, Preferably it is 90% or more, More preferably, it is 93-98%. And the glass nonwoven fabric of this invention uses 90 weight% or more of flat glass fibers which have the said specific flat ratio and filling rate, and whose conversion fiber diameter is 5-17 micrometers, and remove | excluded a binder, and The amount of the binder is 3 to 8% by weight.

  Since the glass fiber nonwoven fabric of the present invention uses the highly flat glass fiber having the above-described configuration, most of the flat glass fibers are overlapped with the flat surface down when paper is formed from the flat glass fiber to form the nonwoven fabric. As a result, the bulk density is increased, the contact area between the overlapping flat glass fibers is increased, the nonwoven fabric can be given high strength by bonding with a small amount of binder, and the smoothness of the surface of the nonwoven fabric itself. Is good. Thus, the present invention can provide a thin glass fiber nonwoven fabric that is thin, has a high bulk density, has a high surface smoothness, and uses a small amount of binder, and the laminate produced using the glass fiber nonwoven fabric has a high glass fiber content. , Good dimensional stability, excellent hot water resistance, excellent heat resistance, and excellent surface smoothness. For this reason, it can be used as an insulation reinforcement material for printed wiring boards instead of glass cloth. Can be manufactured.

Hereinafter, the present invention will be described in detail.
High flat glass fiber In this specification, when the long diameter and the short diameter of the cross section of the high flat glass fiber are assumed to be a rectangle 2 circumscribing the cross section of the flat glass fiber, as shown in FIG. The length A of the side 2a (corresponding to the longest dimension of the fiber cross section) and the length B of the short side 2b (corresponding to the longest dimension substantially perpendicular to the major axis of the fiber cross section) are shown. The flatness ratio in the present invention is represented by the ratio of the major axis to the minor axis, that is, the longest minor axis (A / B) perpendicular to the longest axis / longest axis.
The converted fiber diameter of the high flat glass fiber is expressed in terms of the fiber diameter of a circular cross-section glass fiber having a cross-sectional area equal to the cross-sectional area of the flat glass fiber. It calculates by calculation from the number of the glass fiber to comprise, the density of glass fiber itself, or the area of a fiber cross section.
The composition of the highly flat glass fiber used in the present invention is not particularly limited as long as it can produce glass fiber such as E glass, ECR glass, S glass, C glass, and D glass.

  The flatness ratio of the highly flat glass fiber used in the present invention needs to be 2.0 to 10. Here, when using the high flat glass fiber of this invention for a glass fiber nonwoven fabric, it is preferable that flat ratio is 3.1-8, More preferably, it is 3.1-5, Most preferably, 3.5- 4.5. If the flatness ratio is less than 3.1, the minor axis is large, so the thickness of the nonwoven fabric is reduced, and the effect of increasing the glass fiber content in the laminate is not sufficient, and when flat glass fiber is made, The flat glass fibers deposited on the net tend to stand up with the long-diameter end facing downward, the bulk density becomes low, and the glass fiber content in the laminate cannot be made comparable to glass cloth. . On the other hand, when the aspect ratio is greater than 8, problems such as excessive drainage time during papermaking and a slow impregnation rate of the resin to the nonwoven fabric occur, and the rate of increase in bulk density is low.

Furthermore, the high flat glass fiber used in the present invention has a filling rate of 85% or more, preferably 90% or more, and more preferably 93 to 98%. That is, in FIG. 2, when the cross-sectional area of the glass fiber 1 is S and the area of the rectangle 2 is S ₀ ,
Filling rate (%) = S × 100 / S ₀ ≧ 85 (1)
(The cross-section of the flat glass fiber 1 in FIG. 2 is merely for explaining how to measure the dimensions, and is not of this characteristic). Hereinafter, for convenience of explanation, “S × 100 / S ₀ ” is referred to as a filling rate (%). When this filling rate is set to 85% or more, particularly 90% or more as in the formula (1), the cross section of the flat glass fiber becomes a shape close to a rectangle, and the long side thereof is straight, loosely convex, or loosely concave. Draw a curve close to a straight line. Accordingly, the flat glass fibers have many substantially flat surfaces, and when the flat glass fibers are made, the flat glass fibers are easy to overlap with the substantially flat surfaces facing down. It becomes possible to make a nonwoven fabric, and the substantially flat surfaces of the overlapped flat glass fibers are in contact with each other or are in close proximity with each other, including a water-soluble binder or a binder dissolved in a solvent, The adhesion effect due to is greatly increased. For this reason, when manufacturing a thin nonwoven fabric having a thickness of about 50 μm and a basis weight of about 15 to 40 g / m ^{2, the} strength required for the nonwoven fabric (for example, a prepreg in a subsequent process) is required even with a small binder amount of about 3 to 8% by weight. Strength required for creation). Moreover, the surface smoothness of the nonwoven fabric is improved, and the surface smoothness of the laminate using the nonwoven fabric is also improved. In addition, since it will become a shape substantially equal to a rectangle when a filling rate is made still larger than 98%, manufacture of the flat glass fiber of the shape becomes very difficult.

The flat glass fiber is produced by solidifying the molten glass while preventing the molten glass drawn from the nozzle chip from having a circular cross section when the molten glass is discharged from the flat nozzle chip and spun. For this reason, the cross-sectional shape of the flat glass fiber is slightly different depending on the position of the nozzle tip even if the fibers are spun simultaneously from the same nozzle plate, and it is difficult to specify the exact shape, but it can be defined as follows. That is, the cross-sectional shape of the flat glass fiber cross section satisfying the above formula (1) used in the present invention is a rectangle with four rounded corners, as shown by the hatched portion in FIG. As indicated by the hatched portion in b), the rectangle is semicircular at both ends of the rectangle, an ellipse having a part of an ellipse or a curved surface similar to it, or a composite shape thereof. In addition, the code | symbol 1 in FIG. 1 shows a high flat glass fiber.
About the thickness of the high flat glass fiber of this invention, the thing of various fiber diameter can be manufactured by the setting of manufacturing conditions. However, it is preferable in production that the minor axis in the cross section is 3 to 20 μm, preferably 4 to 15 μm, and the longest diameter is 6 to 100 μm, preferably 15 to 80 μm. That is, when the short diameter is less than 3 μm, it is difficult to spin the glass fiber itself, and when the long diameter exceeds 100 μm, the flattening efficiency is poor and the rigidity is too high. Efficient production is not possible.
Further, it is desirable that the nonwoven fabric has a bulk density similar to that of a glass cloth and has a minor axis of 4 to 10 μm and a major axis of 15 to 40 μm.

  The converted fiber diameter of the high flat glass fiber is 5 to 17 μm (short diameter B = about 2.8 to 9.6 μm), preferably 7 to 15 μm, more preferably 9 to 14 μm. Suitable for use on glass fiber nonwoven fabrics. If the converted fiber diameter is smaller than 5 μm, economical spinning becomes difficult, and the number of glass fibers with the same weight increases because the fibers are too thin, and the bulk density of the nonwoven fabric becomes smaller. It is difficult to make a laminate close to the density of a laminate using a glass cloth using a cross-sectional glass fiber. On the other hand, when the converted fiber diameter exceeds 17 μm, the fiber becomes too thick and the rigidity is high, which causes problems in fiber orientation and dispersion in the paper making process. In addition, the number of glass fibers constituting the nonwoven fabric is reduced. As a result, voids increase in the nonwoven fabric, the binder is likely to come off, and the surface smoothness of the laminated sheet is poor. Furthermore, since the number of contact points between the fibers decreases, it is necessary to increase the adhesion amount of the binder to ensure the strength.

The high flat glass fiber of this invention is not necessarily used only for manufacture of a glass fiber nonwoven fabric, but can be used for the various uses for which the glass fiber was used conventionally. In particular, it is possible to increase the content of glass fiber in products compared to conventional glass fiber, so in addition to nonwoven fabrics, injection molding, filament winding, hand lay-up molding, spray-up molding, resin injection molding The fiber reinforced plastic produced by using a molding method such as pultrusion molding, press molding, or continuous molding has various effects such as remarkable increase in physical strength, dimensional stability, and surface smoothness.
Also, products having the same form as conventional glass fiber products can be manufactured. For example, roving, chopped strands, milled fibers, chopped strand mats, roving cloths, glass cloths, yarns as well as circular cross-section glass fibers. It can also be used as a product. In addition, flat glass fibers can be produced from acid-resistant glass compositions with a large surface tension, which can be produced in a wide range, and it has been difficult to produce, so the acid resistance, corrosion resistance, and gas barrier properties of FRP should be improved. Open new applications such as

Manufacturing method of highly flat glass fiber As a method of manufacturing the highly flat glass fiber of the present invention, it can be manufactured in the same manufacturing process as that of a conventional glass fiber manufacturing method. That is, molten glass flowing out from a large number of nozzle tips is first made into fibers at a high speed, and then a bundling agent or the like is applied to improve handling and protect the glass fibers.
A glass yarn used for a woven fabric is used as a warp or a weft by adding a sizing agent in which a conventionally known film forming agent is a starch or resin. Moreover, when using for paper and a nonwoven fabric, it processes with surfactant, a water-soluble film formation agent, a silane coupling agent, etc., for example.
Also when used for FRP, for example, resins having film forming ability such as epoxy resins and urethane resins, antistatic agents such as quaternary ammonium salts, γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyl The same known sizing agent as that used for ordinary glass fibers containing a silane coupling agent such as trimethoxysilane and γ-aminopropyltriethoxysilane is used in accordance with the purpose. 5% by weight is deposited and focused.

  Since there are various differences in the production conditions of the glass fiber depending on the composition, general conditions will be described by taking as an example the case of a glass fiber having an E glass composition. In general, glass fiber is produced by spinning molten glass from a bushing in which a large number of nozzle tips are formed. At this time, when the molten glass in the bushing is E glass, the glass fiber has a high temperature of about 1200 ° C., and 1000 poise. Have a degree of viscosity. When spinning a deformed cross-section glass fiber such as a flat glass fiber at a high speed from a molten glass having such a low viscosity and a high surface tension, for example, a nozzle tip having a non-circular cross section is used as disclosed in JP-A-1-266937. Even if it is used, the length of the hole is long and the resistance is large in order to draw the molten glass from the hole provided in the nozzle tip, so the outflow amount of the molten glass is applied to the nozzle provided on the flat nozzle plate without the nozzle tip. There was a phenomenon in which the cross-sectional shape of the product became unstable because the cooling was insufficient when the nozzle tip length was shortened. In order to sufficiently increase the spinning speed, it is necessary to increase the area of the holes and increase the amount of molten glass supplied. However, if the hole is enlarged, the glass is not cooled sufficiently and the tendency to become round due to surface tension cannot be suppressed. Thus, in the conventional non-circular cross-section nozzle tip, when spinning a high flat glass fiber at high speed, it is difficult to obtain a product having a desired cross-sectional shape, and further improvement of the nozzle tip shape has been demanded. That is, in the nozzle tip disclosed as the prior art, there is a problem that when flat glass fibers having a flatness ratio of 2.0 or more are spun at a high speed of 1500 m / min or more, there are many yarn breaks and the cross-sectional shape becomes unstable. There was a point. In particular, the glass fiber with good acid resistance called ECR glass has a large surface tension, and the conventional nozzle tip cannot produce a flat glass fiber having a flatness ratio of 2.0 or more stably and with high productivity. There was a point.

Glass fiber spinning nozzle tip On the other hand, the glass fiber spinning nozzle tip of the present invention overcomes the problems in the conventional nozzle tip, has a flatness ratio of 2.0 to 10, and a filling rate of 85% or more. Preferably, 90% or more highly flat glass fibers can be stably produced at high speed.
That is, the glass fiber spinning nozzle tip of the present invention is a nozzle tip to be installed on a nozzle plate (a plate on which a number of nozzle tips are installed), or a part of the nozzle hole wall of the nozzle cut out, or By forming the glass reservoir in the upper part of the nozzle, the outflow amount of the molten glass and the cross-sectional shape of the flat glass fiber are stabilized in high speed spinning, and has the following configuration.

(1) A high-flat glass fiber spinning nozzle chip including a protruding nozzle portion and a nozzle hole penetrating the nozzle portion, wherein the nozzle hole is a pair of major-diameter nozzle hole walls and a minor-diameter nozzle hole It consists of a wall, and the major axis / minor axis ratio of the nozzle hole is 2.0 to 10, and the nozzle hole wall in one major axis direction is provided with a concave nozzle hole wall notch in the cross section. Characteristic nozzle tip for spinning high flat glass fiber.
(2) The notch depth in the concave nozzle hole wall notch is 10% to 100% with respect to the length of the protruding nozzle as shown in FIG. 4. High flat glass fiber spinning nozzle tip.
(3) The above-mentioned (1) or characterized in that a molten glass pool part having a molten glass inflow part area 1.5 to 8 times the area of the nozzle hole is provided on the upper part of the protruding nozzle part. (2) A nozzle chip for spinning a highly flat glass fiber.

  Here, the outer shape of the nozzle tip may be a cylindrical shape as long as the desired nozzle tip hole is provided. However, if the outer shape is a rectangular parallelepiped or a similar shape, the nozzles are limited. A large number of nozzle tips can be arranged in an orderly and dense manner. The relationship between the arrangement of the nozzle tips and the winding device is such that the direction in which a large number of nozzle tips are arranged is arranged in the same direction that is substantially parallel to the central axis of rotation of the winding device, or in a direction perpendicular thereto. May be. In addition, when the external shape is simplified, the production of the nozzle plate is not limited to the method of attaching the nozzle tip to the nozzle plate by welding, but by machining such as a commonly used milling machine or end mill, or by electric discharge machining or pressing. There are advantages such as easy creation from a single plate.

Next, the structure of the nozzle tip for glass fiber spinning used in the present invention will be outlined with reference to the drawings, and the structure of each part will be described in detail together with its function. 3, 4 and 5 are views showing an example of a nozzle chip for spinning a high flat glass fiber according to the present invention, FIG. 3 is a perspective view thereof, FIG. 4 is a sectional view taken along line XX ′ thereof, and FIG. FIG. 5 is a plan view seen from below.
The cross-sectional shape of the nozzle tip is not limited to the inverted convex shape as shown in FIG. 4, but may be a rectangular shape as shown in FIG.

  The nozzle tip 11 used in the present invention has a protruding nozzle portion 13 (hereinafter sometimes abbreviated as “nozzle portion 13”) that has a large influence on the cross-sectional shape of the flat glass fiber. Here, the nozzle portion 13 is a nozzle tip having an opening having the same cross section as the nozzle hole 14 before cutting out a part of the nozzle hole wall 15. However, in the nozzle tip 11 of the present invention, a pair of long diameters are used. The nozzle hole wall in one major axis direction is provided with a nozzle hole wall notch portion 15 ′ having a concave shape in cross section. Here, the “cross section” means a cross section of the nozzle hole wall 15 when viewed from the direction perpendicular to the plane parallel to the major axis direction of the nozzle hole 14, and “nozzle hole wall notch 15 ′”. The term “nozzle wall wall 15” refers to a portion where the central portion of the nozzle hole wall 15 is cut out from the nozzle tip tip direction. Therefore, the nozzle hole wall provided with the concave nozzle hole wall cutout portion 15 'in the cross section is such that, as shown in FIGS. It has a shape. Accordingly, a nozzle chip (FIG. 6) in which the nozzle plate 13 without the molten glass reservoir is directly connected to the nozzle plate 17 (FIG. 6), or a nozzle chip having a structure in which the molten glass reservoir 12 is provided on the nozzle 13 (FIG. 18) is also present. It is included in the nozzle tip of the invention.

In a state where there is no remaining portion at both ends of the nozzle hole wall 15 on the long diameter side that has been cut away, that is, when the entire one long diameter side becomes the nozzle hole wall cutout portion 15 ′, the nozzle tip The long diameter / short diameter ratio of the cross-section of the product after spinning is much smaller than the ratio of the long diameter / short diameter of the molten glass when exiting from the flattening efficiency (flat ratio of flat glass fiber / long diameter of nozzle hole / There arises a problem that the ratio of the minor axis is reduced. Therefore, it is necessary to leave both ends of the nozzle hole wall 15 on the long diameter side to such an extent that the tendency of the molten glass to be rounded can be suppressed at least at both ends of the nozzle tip.
When the nozzle tip 11 having the structure shown in FIG. 3 provided with the molten glass reservoir 12 for stabilizing the flow of the molten glass and stabilizing the flat shape is used for the nozzle portion 13, a more stable cross-sectional shape is obtained. High aspect ratio glass fibers can be spun at higher speed. Furthermore, in this nozzle tip arrangement in which a large number of nozzle tips are arranged, a spinning condition with a flattening efficiency of 100% or more can be obtained by disposing cooling fins close to the nozzle hole wall surface having the nozzle hole wall notch 15 ′.

  The bottom surface of the nozzle tip is provided with a nozzle hole 14 composed of a pair of long-diameter direction nozzle hole walls and a short-diameter direction nozzle hole wall. In order to obtain a high-flat irregular cross-section glass fiber having a major axis / minor axis ratio, that is, a flatness ratio of 2.0 to 10, the shape thereof is a rectangle, a shape having a semicircular shape attached to both ends of the rectangle, or a shape similar thereto. , An elliptical shape, a dumbbell shape, or a shape close to these, and the ratio of the long side to the short side or the longest major axis to the longest minor axis perpendicular thereto is 2.0 to 10, preferably the major axis / minor axis ratio. 3-8. When the major axis / minor axis ratio is 2 or less, it is difficult to obtain glass fibers having a flatness ratio of 2.0 to 10, and when the major axis / minor axis ratio is 10 or more, the cross-sectional shape of the fiber tends to be unstable, and efficient production is difficult. It is.

  The shortest diameter of the nozzle hole 14 is adjusted to match the type and production amount of the molten glass, but is desirably 0.5 mm or more, preferably 0.8 mm or more. If it is less than 0.5 mm, the outflow of the molten glass is not smooth, and the fiber dimensional change is large and undesirable. The length C of the nozzle hole is preferably 1 to 6 mm, and more preferably 1 to 4 mm. Further, the tip of the nozzle tip needs to protrude from the surface of the nozzle plate by at least 0.2 mm. If the protruding height of the nozzle tip 11 from the lower surface of the nozzle plate is low, the cooling effect is not clear, and if it is too high, the cooling effect is too effective and the viscosity of the glass increases, making it unsuitable for making flat glass fibers into fibers.

As described above, the molten glass reservoir 12 may be provided above the nozzle hole 14 of the nozzle tip 11 in order to stabilize the flow of the molten glass and to stabilize the flat shape. The cross-sectional area, that is, the molten glass inflow portion area is 1.5 to 8 times, preferably 2 to 5 times the area of the nozzle hole 14. Below 1.5 times, there is little difference from the conventional nozzle tip that is straight and has no glass reservoir. Above 8 times, dead zones are formed in the glass reservoir, and high viscosity molten glass is likely to be produced. Not only has an adverse effect on the stabilization of the cross-sectional shape of flat fibers, but also the cross-sectional area of the nozzle tip with a glass pool increases, and the number of nozzle tips that can be placed in the same area decreases, resulting in the production of high flat glass fibers This is because of the decrease.
In a nozzle tip provided with a glass reservoir in the upper part of a nozzle hole of a glass fiber spinning nozzle tip having a circular cross section, a cylindrical or conical reservoir is generally provided, but in the present invention, it is close to the wall surface due to a cooling effect. In order to increase the viscosity of the molten glass of the part and improve the flatness efficiency and to make it suitable for the cross-sectional shape for producing the distribution of outflow amount because the long diameter of the nozzle hole is long, for example, when the nozzle hole is oblong, Although the shape of the nozzle may be similar to the orifice diameter, the cooling and flow of the glass in the nozzle tip can be controlled by changing the shape of the reservoir, such as a rectangle or a dumbbell shape.

The molten glass reservoir has a cross-sectional shape in which the shape of the inlet is straight down to just above the nozzle hole, or a tapered shape in which the inlet and nozzle hole are connected by a smooth surface and have almost no step. .
The area of the molten glass pool portion 12 is larger than the opening cross-sectional area of the nozzle portion 13 and can be provided in a range that does not hinder the installation of the adjacent nozzle tip, and the depth is the length of the entire nozzle tip 11 and the nozzle hole 14 portion. The length is determined in consideration of the degree of cooling of the molten glass and the turbulence of the flow. The depth is from 0 mm to twice the thickness of the nozzle plate, preferably 1 to 2 times. If the depth is shallow, the effect is small. If the depth is too deep, the glass is cooled too much and the discharge amount of the molten glass from the nozzle tip is reduced, or the cross-sectional shape of the flat glass fiber is likely to be unstable.

Furthermore, in order to suppress the force that the molten glass drawn out from the nozzle hole tends to be rounded by surface tension, the maximum width of the short diameter of the nozzle hole 14 is set on the tip surface of the short diameter nozzle hole wall at both ends of the nozzle part 13. A concave groove having a width not exceeding and a depth of 0.1 to 0.7 mm is provided, or the minor diameter portion is extended at both ends of the major diameter of the nozzle hole or the height relative to the minor diameter portion is 0. Providing a convex edge of 1 to 0.7 mm is effective in that the flat cross-sectional shape is further stabilized.
The specific shape and dimensions of the molten glass reservoir 12, the short diameter and long diameter dimensions and shape of the nozzle hole 14 are the thickness of the nozzle hole wall 15, the type of molten glass, the spinning temperature, the winding speed of the glass fiber, Since it varies greatly depending on the spinning conditions such as the flatness ratio of the flat glass fiber to be produced, the converted fiber diameter, and the product quality, it can be appropriately determined by experience and experiment.
The present invention stabilizes the cross-sectional shape by applying appropriate processing to the nozzle portion 13 provided on the bottom surface of the nozzle tip 11 to suppress the force that the molten glass drawn from the hole tends to be rounded by surface tension. It enables high speed spinning.

  As a specific shape, the length (width) of the nozzle hole wall cutout portion 15 ′ has the effect of increasing the surface tension of the molten glass together with the height of the cutout portion 15 ′ and increasing the flattening efficiency. However, in consideration of various factors such as glass melting temperature, glass fiber spinning speed, and flatness ratio stability, the nozzle hole wall length in the major axis direction is 30% to 100%, preferably 40 to 90%. Preferably, the effect is exhibited by cutting out a portion of 50 to 80%. If it is less than 30%, the effect of the notch is small, and if it is 100% notched and further the short side portion is ½ or less, it becomes supercooled and the flattening efficiency is deteriorated. Further, the length of the major axis varies greatly depending on the winding speed of the spinning, the production amount, the flattening efficiency, etc., but the major axis does not exceed 15 mm in width. In addition, when a plurality of short diameters of nozzle holes are present in one nozzle tip, the shorter numerical value is set as the short diameter of the nozzle.

Moreover, it is preferable that the notch depth in the said concave nozzle hole wall notch part 15 'is 10%-100% with respect to the length of the protruding nozzle part 13, More preferably, it is 30%-80%. is there. Here, “the length of the protruding nozzle part” means that the protruding part obtained by subtracting the virtual minimum nozzle length of 0.3 mm from the nozzle hole length C when the nozzle tip has a molten glass reservoir. The length of the nozzle hole refers to the length of the nozzle hole in the case of a nozzle chip without a molten glass reservoir. The protruding portion refers to a portion protruding from the lower surface of the nozzle plate. If it is 10% or less, the effect of the notch is small, and it is necessary to notch at least 0.2 mm.
Furthermore, in the present invention, there is provided a nozzle chip for high flat glass fiber spinning including a protruding nozzle part and at least one set of nozzle holes penetrating the nozzle part, wherein the nozzle hole includes a pair of long-diameter nozzle hole walls and It consists of a nozzle hole wall in the short diameter direction, and the nozzle hole wall on the nozzle chip wall surface side of the nozzle hole wall in the long diameter direction is provided with a nozzle hole wall notch that is concave in cross section, and the nozzle hole that is concave in cross section Use of a nozzle chip for spinning a high flat glass fiber (see FIGS. 7 and 8), characterized in that each nozzle hole is arranged so that the nozzle hole walls in the major axis direction without a wall notch are continuous with each other. Is also possible. FIG. 7 shows a nozzle chip in which one set of nozzle holes is arranged, and FIG. 8 shows a nozzle chip in which two sets of nozzle holes are arranged.

Flat glass fiber spinning nozzle tip arrangement method and flat glass fiber manufacturing apparatus As described above, a nozzle hole wall notched in the cross section is provided in one major diameter nozzle hole wall as applied in the present invention. By using the glass fiber spinning nozzle tip, it is possible to stably produce a high flat glass fiber at a high speed. In a conventional flat glass manufacturing nozzle, in order to rapidly cool the molten glass flowing out in a flat shape into a glass fiber having a large flatness ratio, cold air is blown toward the nozzle. However, the nozzle provided with the notch portion according to the present invention has a high cooling effect, and when cooling with conventional cold air is performed, the cooling rate is too fast, so that it is difficult to produce a thin fiber diameter, and the amount of air is reduced. When the flatness ratio of the spun fiber is increased, the air flow becomes uneven and the variation in the flatness ratio of the product tends to increase, and it is necessary to perform spinning while devising a cooling method.

Therefore, the use of cooling fins used in the production of conventional circular cross-section glass fibers whose cooling effect is smaller than that due to cold air is studied, and the flattening efficiency when arranged between the nozzles in parallel with the major axis of the nozzle (see FIG. 12) As a result, it was found that the spinning state was stabilized, and it was confirmed that it could be used for the production of flat glass fibers.
When flat glass fibers are spun, glass fibers having irregular cross-sections spun with a spinning nozzle tip whose notch is parallel to the longitudinal direction of the nozzle plate as shown in FIG. 15 are collected in one or several bundles. However, the sizing agent is applied by an applicator and wound up. At this time, the long side surface of the irregularly shaped fiber is in contact with the surface of the coating apparatus such as a roller or a wide belt on which the sizing agent is adhered. In order to facilitate, the long side of the fiber to be spun and the rotation axis of the roller of the sizing agent coating device are installed in parallel. For this reason, the entire spinning apparatus is composed of the direction of the rotation axis of the winder that winds the spun glass fiber, the direction of the rotation axis of the roller type or belt type applicator for applying the bundling agent, and the direction of the major axis of the nozzle tip. The longitudinal directions of the nozzle plates are all arranged substantially in parallel (see FIGS. 15 and 17).
Since the spun glass fibers are collected at the center as shown in FIG. 17, the glass fibers drawn from the spinning nozzle tips arranged at both ends in the longitudinal direction of the nozzle plate are obliquely downward along the long side. It is drawn and stretched. As a result, there is a problem that the flatness ratio is reduced, and the flatness ratio of the glass fibers produced from the center and end nozzle tips is different.

In order to effectively cool the nozzle tip on the nozzle plate, it is effective to cool the wall surface of the nozzle tip hole having a large area, but the conventional notch portion shown in FIG. The arrangement of nozzle tips arranged parallel to the longitudinal direction has a long nozzle tip arrangement, and thus the length of the cooling fins inevitably has to be long. There is a shortage, and the degree of cooling varies depending on the location. As a result, if the cooling is appropriate, the flatness ratio is large, the flatness ratio of the glass fibers spun from the undercooled nozzle tip is small, and the variation of the flatness ratio is further increased in the same glass fiber bundle. there were.
Therefore, in view of such a problem, the present invention reduces the length of the cooling fin by arranging the spinning nozzle tip major axis direction perpendicular to the longitudinal direction of the nozzle plate, that is, parallel to the lateral direction. By reducing unevenness in the cooling effect of the tip and base of the fin, variation in the flat ratio of the obtained glass fiber is reduced, and in addition, the nozzle hole wall surfaces provided with the concave nozzle hole wall notches face each other. The nozzle tips are arranged on the nozzle plate, and cooling fins are arranged between them to increase the temperature difference between the notch and the protruding portion of the remaining wall. Another object of the present invention is to provide a glass fiber spinning nozzle tip that can be manufactured with high quality and stable quality, and a nozzle tip arrangement method therefor.
In the conventional cooling method using cooling fins, it was thought that there was a limit to improving quality and productivity, but the present inventors found that there was little difference depending on the location of the cooling effect in the cooling fin, and it was stable. Focusing on the advantages of being able to produce quality products and easy maintenance and inspection, various studies were conducted on how to effectively use these advantages.

As a result, in order to achieve the above object, the present inventors have arranged the nozzle tip long side at right angles to the longitudinal direction of the nozzle plate, in other words, by arranging the nozzle tip row parallel to the axis in the short direction. The length of the nozzle is shortened, the effect of the cooling fins is made uniform, these problems are solved by promoting the cooling of the notched part, and the concave nozzle hole wall notch in the protruding nozzle part It was discovered that these problems can be solved more effectively by keeping the wall surface of the nozzle hole where no nozzles exist, and various studies were made on the notch surface of the nozzle tip, the position of the cooling device, and the nozzle tip shape. .
Conventionally, as in the present invention, when glass fibers are manufactured using a nozzle plate in which the long sides of the nozzle tip are arranged in parallel with the short direction of the nozzle plate (see FIGS. 9 and 10), the flatness that has come out of the nozzle tip is produced. After the glass has been stretched and contacted as it is standing at right angles to the coating device surface, it tends to fall randomly in either the left or right direction, so that it is focused at various angles as shown in FIG. It was thought to be a lot of glass fiber bundles. For this reason, such nozzle tip arrangement has not been performed. However, as a result of trial production by the present inventors, the result of winding was unexpected even when spinning with an apparatus in which the long side of the nozzle tip was aligned in parallel with the longitudinal direction of the nozzle plate or with an apparatus aligned at a right angle. In addition, it was found that there was no difference in the state in which the fibers were arranged, and the bundle of bundles was a state in which flat fibers were arranged in the same direction and there were few gaps (see FIG. 14). The fibers in the bundle of bundles cannot be clearly confirmed how the fiber arrangement changes in the process from spinning to winding, but there is almost no difference in the arrangement of the two fibers. It is presumed that when the molten glass coming out of the nozzle tip is stretched and comes into contact with the surface of the sizing agent coating device, it is arranged flat on the surface.

  As described above, since the nozzle tips can be arranged, the length of the cooling fin arranged on the surface can be shortened, the unevenness of the cooling effect of the tip and base of the fin is reduced, and the obtained fiber A fairly satisfactory result can be obtained with respect to variation in the aspect ratio. When the cooling fins are arranged between the nozzle tips of the nozzle tip shown in FIG. 3 in which all the notch portions 15 ′ are aligned in one direction, the notch portion 15 ′ is provided on one side of the cooling fin. The other surface is opposed to the wall surface of the nozzle hole without the notch 15 ′. In the cooling method having such an arrangement, the difference in cooling between the nozzle hole wall surface provided with the notch 15 ′ and the nozzle hole wall surface not provided with the notch 15 ′ is reduced, but the fiber having a sufficiently satisfactory aspect ratio. Is obtained. In addition, as shown in FIG. 9, the nozzle tips are arranged so that the nozzle hole wall surfaces provided with the concave nozzle hole wall notches face each other, and the cooling fins are arranged therebetween. Further, the filling rate and the like are further improved. In addition, when thread cutting occurs because the cooling effect of the notch portion is too great, the nozzle tips are arranged so that the nozzle hole wall surfaces without the notch face each other as shown in FIG. It is also possible to arrange cooling fins.

That is, the nozzle plate 17 of the present invention is characterized in that the major axis direction of the flat glass fiber spinning nozzle chip arranged on the nozzle plate 17 is arranged orthogonal to the longitudinal direction of the nozzle plate 17. In addition, it is preferable that the longitudinal direction of the nozzle plate 17 is arranged at a position parallel to the rotation axis of the sizing agent coating device 23 and / or the rotation axis of the winder 25 (see FIG. 15), and the high flat glass in the present invention. In the fiber manufacturing apparatus, cooling fins are arranged between nozzle rows in the step of spinning flat glass fibers with a long-diameter nozzle tip having a notch on one of the long sides of the nozzle tip wall (see FIG. 12). ).
The above-described embodiment of the present invention will be described with reference to the drawings. The shape of the molten glass outflow portion of the nozzle tip used in the present invention means a shape having a major axis and a minor axis, such as a rectangle, a dumbbell shape, an eyebrows shape, and an oval shape.

In the present invention, the longitudinal direction of the nozzle plate is arranged at a position parallel to the rotation axis of the sizing agent coating device or the winder, and the major axis direction of the nozzle tip and the longitudinal direction of the nozzle plate are arranged orthogonally. Therefore, the row in which the nozzle tips are arranged in the major axis direction is shortened. Therefore, as shown in FIG. 16, the spun glass fibers are collected from the short side surface of each nozzle tip toward the center portion of the nozzle plate. The result is that the difference is relatively small.
In spinning the nozzle tip 11, heat radiation from the nozzle hole wall notch 15 ′ is large, while the nozzle hole wall 15 without the nozzle hole wall notch 15 ′ is preferably kept warm. The reason is that when the heat radiation from the nozzle hole wall notch 15 ′ increases and the temperature of the solvent glass on the surface decreases, the surface tension decreases, and the glass in the nozzle hole wall 15 having the nozzle hole wall notch 15 ′. The molten glass that moves so as to stick to the remaining notched nozzle hole wall surface 16 and flows through the nozzle hole wall 15 without the notched portion 15 ′ having a high temperature and the remaining notched nozzle hole wall surface 16 has a long diameter. Since the end portion is wet and spread, when the molten glass is stretched, there is little change in the cross-sectional shape, and the stretching is completed.

In order to achieve such a state, in the present invention, as illustrated in FIG. 9, a nozzle chip array in which the nozzle hole walls provided with the concave nozzle hole wall notches are opposed to each other is used. is there. As a result, the nozzle tip arrangement is such that the nozzle hole wall notch surfaces 15 'face each other and the nozzle hole walls 15 without the notch 15' face each other. The cooling fins 5 are arranged between the nozzle hole wall notch surfaces 15 'facing each other in the nozzle nozzle rows arranged in this way, and the cooling fins 21 are arranged between the nozzle hole walls 15 without the notch parts 15' facing each other. As shown in FIG. 7, it is particularly preferable that the structure is not arranged.
However, there are cases where the cooling effect on the cooling surface is too great due to differences in composition, molten glass temperature, etc. In such a case, the surfaces with notches are arranged facing each other as shown in FIG. A desired flat glass fiber can be obtained by installing an air-cooled fin between rows in which notched surfaces face each other and spinning. It is not necessary to arrange the air cooling fin 5 between the nozzle hole wall 15 without the notch 15 'in FIG. 9 and between the nozzle hole wall 15 with the notch 15' in FIG. The interval can be narrowed.

  At this time, the nozzle tip for spinning a high flat glass fiber further includes (4) the protruding nozzle portion and at least one set of nozzle holes penetrating the nozzle portion, and the nozzle holes are formed in a pair of major diameter directions. It consists of a nozzle hole wall and a nozzle hole wall in the short diameter direction, and the nozzle hole wall on the nozzle chip wall surface side of the nozzle hole wall in the long diameter direction is provided with a concave nozzle hole wall notch in the cross section. A nozzle chip for spinning a high flat glass fiber, characterized in that each nozzle hole is arranged so that the nozzle hole walls in the major axis direction without the concave nozzle hole wall notch are continuous with each other (see FIGS. 7 and 8). If is used, the shape can be made more compact.

Glass fiber nonwoven fabric The glass fiber nonwoven fabric of the present invention is produced using the high flat glass fiber having the above-mentioned characteristics. At that time, all the fibers constituting the nonwoven fabric may be the high flat glass fiber having the above characteristics. If necessary, other fibers, for example, glass fibers having a circular cross section may be mixed and used. In the case where other fibers are mixed and used, the amount used is 90% by weight or more of the total weight of the nonwoven fabric excluding the binder in order to effectively exhibit the effect of the flat glass fiber having the above characteristics.
The high flat glass fibers used in the glass fiber nonwoven fabric of the present invention may have the same characteristics (the same flat ratio, equivalent fiber diameter, etc.), or may be mixed and used with different characteristics. . When mixed and used, it is preferable to mix and use two types of highly flat glass fibers having different converted fiber diameters. For example, two types of highly flat glass fibers having different converted fiber diameters of 5 to 10 μm are blended at a ratio of 90 to 50% by weight of flat glass fibers having a large converted fiber diameter and 10 to 50% by weight of small flat glass fibers. Are preferably used. Thus, when two types of flat glass fibers having different converted fiber diameters are mixed and used, the bulk density can be further increased due to the effect of filling the gaps between the nonwoven fabrics made of thick fibers with thin fibers, and the flat glass fibers are formed on the surface. There are few irregularities because they are lined up. For this reason, the smoothness of the surface of the laminated board which used this glass fiber nonwoven fabric for the surface layer becomes very high.

In the glass fiber nonwoven fabric of the present invention, the amount of the binder used for fixing the glass fiber is 3 to 8% by weight. When the amount of the binder is less than 3% by weight, the adhesive strength between the glass fibers is insufficient, and it becomes difficult to secure the tensile strength required for the nonwoven fabric. On the other hand, when the amount of the binder exceeds 8% by weight, the binder adversely affects the heat resistance, hot water resistance, and water resistance of the laminate made using the glass fiber nonwoven fabric, and deteriorates the performance of the laminate.
The glass fiber nonwoven fabric of the present invention can be produced as follows. First, the molten glass is stretched by the above-described method or the like and is cooled and solidified in a state where the flat shape is maintained, and then the sizing agent is immediately applied and collected by a known sizing agent coating machine such as a roller applicator. To make a strand.

As the sizing agent, for example, water-soluble polymers such as polyvinyl alcohol, polyethylene oxide, water-soluble epoxy resin, or a mixture of these with a cationic surfactant so that the glass fiber is easily dispersed in water, Alternatively, only a surfactant and a lubricant are used, and 0.05 to 0.5% by weight in terms of solid content is applied to the glass fiber. In the composition of the sizing agent, a known component that improves the adhesion between the fiber and the matrix resin such as a silane coupling agent may be blended. The composition of these sizing agents may be a known composition used for the production of glass fiber nonwoven fabrics by a wet papermaking method, and the same papermaking can be performed without using a special one.
The strand is cut into a length of 3 to 25 mm to form a chopped strand, and then a nonwoven fabric is formed by a wet nonwoven fabric papermaking method.
In this wet papermaking process, a conventionally known method for producing a glass fiber nonwoven fabric (or glass paper) is used. For example, a dispersant, a binder or the like is added in a large amount of water, and glass fiber chopped strands are added. And a paper making process similar to the case of using a circular cross-section glass fiber, in which the glass fiber is dispersed in water by a dispersion mechanism such as a pulper.

The liquid in which the glass fibers are dispersed is dehydrated with a paper machine, and after applying a binder such as an epoxy resin with a spray device or the like, the adhesion is adjusted, dried, and wound into a roll. Alternatively, powdery epoxy resin, water-dispersible epoxy resin or modified epoxy resin is added in advance to the glass fiber dispersion, and the strength as a nonwoven fabric is imparted by drying or curing after papermaking. The glass fiber nonwoven fabric of this invention can be manufactured as mentioned above.
The glass fiber nonwoven fabric of the present invention is used as an intermediate layer of a printed wiring board with a double-sided copper foil called composite CEM-3, as well as a known glass fiber nonwoven fabric. It can be used at any position on the board. In particular, since the glass fiber content is high and the surface smoothness is excellent, the copper foil bonding surface of the printed wiring board (for example, the surfaces on both sides of a double-sided copper foil-coated printed wiring board, and the surface of each layer of a multilayer printed wiring board) ) Is preferably used.
In addition, the glass fiber nonwoven fabric of the present invention is not limited to use for printed wiring boards, and can be used for any other purpose. For example, when used for FRP, there is no special consideration, and normal glass fiber It can be handled in the same manner as the nonwoven fabric and the surfacing mat, and a molded product with further improved surface smoothness can be obtained.

The glass fiber nonwoven fabric of the present invention has the above-described configuration and has the characteristics described below.
As described above, since the flat glass fiber having a flatness ratio of 2.0 or more, preferably 3.1 or more is used, the flat glass fiber does not stand on the wire mesh with the short side down. The bulk density is increased and the aspect ratio is 10 or less, preferably 8 or less, so that the drainage time is short in the paper making process and the resin impregnation of the product is good.
In addition, when using a mixture of large and small conversion fiber diameters, the bulk density can be further increased by the effect of filling the gaps in the nonwoven fabric made of thick fibers with thin fibers, and on the surface of the laminate. Since flat glass fibers are arranged, there are few unevenness | corrugations and smoothness improves.

Further, since the filling rate of the flat glass fiber is 85% or more, preferably 90% or more, more preferably 93 to 98%, the side surface of the glass fiber (the portion corresponding to the long side of the cross section) is very close to a flat surface. The flat glass fibers that are overlapped are in a state in which the surfaces close to the plane are in contact with or close to each other. Therefore, the adhesion effect near the contact point is greatly improved, the tear strength of the nonwoven fabric is high even with a small amount of binder between fibers, and the amount of binder that adversely affects heat resistance and water resistance should be as small as 3 to 8% by weight. Compared to conventional laminates using non-woven fabric, high performance can be obtained.
Further, since flat glass fibers having a flatness ratio of 2.0 or more, preferably 3.1 or more are uniformly dispersed in random directions, there is almost no directionality in physical properties such as strength and coefficient of thermal expansion.
Therefore, combined with the effect of the high bulk density of this nonwoven fabric, the warp and thermal expansion coefficient of the laminate using this nonwoven fabric are smaller than those using glass cloth. This is a very important factor for reducing the defective rate of products using printed wiring boards.
When a hole is made in a laminated board with a laser, the glass fiber melts at the high temperature of the laser beam and adheres to the surface of the hole as an amorphous solidified substance called dross, but the flat glass fibers constituting the laminated board are in the major axis direction. This is because the fibers are overlapped in parallel with the non-woven fabric surface, or because the change in the minor axis of the fiber is small, the melt is uniform and the dross adherence is uniform and the hole has a clean inner diameter.

Nonwoven fabric has no texture like glass cloth. In addition, when flat glass fibers with different converted fiber diameters are mixed and used, even if thick fibers are used, the gap between thick fibers is filled with thin fibers so that the packing density increases, and circular glass fibers are used. The surface is smoother than the non-woven fabric, and the surface is even smoother than the conventional non-woven fabric using flat glass fibers such as an elliptical shape and an eyebrows shape.
As described above, the glass fiber nonwoven fabric of the present invention has a high bulk density and is very smooth with flat glass fibers arranged on the surface. In the process of making a prepreg by impregnating this with a resin, Even if the solvent is removed, the volume of the resin portion is reduced, and a so-called sink phenomenon in which the resin moves from the surface to the inside occurs, the sink is minute because the amount of the resin is small. Also, in the molding process, volume shrinkage of the resin occurs after press hot pressing, but the volume shrinkage is very small. For this reason, a large dent does not occur on the surface of the laminate, and the surface smoothness is very good. As a result of confirmation by the inventors, as shown in Examples and Comparative Examples described later, when conventional glass cloth or elliptical cross-section glass fiber was used, the surface irregularities were about 4 μm or less, but the present invention When the glass fiber nonwoven fabric prepared in step 1 was used, surface irregularities could be suppressed to about 2 μm. For this reason, when the glass fiber nonwoven fabric of the present invention is used for the copper foil bonding surface of the printed wiring board, the surface becomes very smooth, and thus the copper foil surface becomes very smooth and adheres to the copper foil. As a result, the copper foil can be etched extremely uniformly. As a result, it is particularly effective for the use of ultrathin copper foil of 5 to 10 μm and for improving the reliability of fine lines of multilayer boards.
Furthermore, the glass fiber nonwoven fabric of the present invention has a higher bulk density than conventional nonwoven fabrics, so the content of strong glass fibers increases in the molded laminate, and the molded product is a laminate using glass cloth. The plate-like heat resistance, through-hole reliability, and the effect of preventing warpage more than a laminated board using glass cloth can be exhibited.

EXAMPLES In order to deepen the understanding of the present invention, examples will be described in detail below. However, the present invention is not limited to these examples.
Manufacture of high flat glass fiber

In each nozzle part of the nozzle tip with the same length as the major diameter of the nozzle hole installed on the nozzle plate, the area of 3.0 times and the glass reservoir with the depth of twice the nozzle plate thickness, As shown in FIG. 3, a cylindrical hole is straightly drilled near both ends of a rectangular parallelepiped protruding from the nozzle plate, and the two holes are connected by a slit having a width smaller than the diameter of the hole so that the holes are continuous. A nozzle tip having a nozzle diameter of 4 mm and a major axis / minor axis ratio of 4.1 was used as a nozzle tip. In addition, a nozzle hole wall notch portion in which 60% of the major axis width and 30% of the 3 mm nozzle hole length were cut off was provided on one side of the nozzle hole wall in the major axis direction.
The melt of E glass composition was spun at a spinning temperature of 1200 ° C. and a spinning speed of 2000 m / min. The cross section of the spun filament has a major axis of 18.4 μm, a minor axis of 4.5 μm, and a converted fiber diameter of 10 μm, and it is possible to stably obtain glass fibers similar to the shape shown in FIG. done.
The flatness ratio was 4.0, the flattening efficiency was 97.5%, and the filling rate of flat glass fibers was 94.6%.

Flat glass fibers were spun in the same manner as in Example 1 except that the molten glass reservoir in Example 1 was removed.
The melt of E glass composition was spun at a spinning temperature of 1200 ° C. and a spinning speed of 1500 m / min. The cross-section of the spun filament was able to stably produce a rectangular glass fiber having a major axis of 18.5 μm and a minor axis of 5 μm with curved ends.
The obtained fibers had an average flatness ratio of 3.7, flattening efficiency of 90.2%, and flat glass fiber filling ratio of 94.2%.

  The nozzle tip of Example 1 was manufactured under the same conditions as in Example 1 except that the end face of the tip of the nozzle tip was provided with grooves having the same width as the minor axis of the nozzle tip opening and a depth of 0.5 mm at both ends. The flatness ratio was 4.0, the flattening efficiency was 98.2%, and the filling rate was 94.6%.

  Produced with the same width as the short diameter of the nozzle hole and a height of 0.5 mm at the position in contact with both ends of the long diameter of the tip surface of the cutout nozzle tip of Example 1, and manufactured under the same conditions as in Example 1 did. The flatness ratio was 4.0, the flattening efficiency was 98.6%, and the filling rate was 94.6%.

Comparative Example 1

A flat glass fiber was produced in the same manner as in Example 1 except that the nozzle hole wall notch was not provided in the nozzle tip in Example 1. The production amount of flat glass fiber per unit time was 60% of Example 1.
The obtained fiber had an average flatness ratio of 1.65, flattening efficiency of 41.3%, and flat glass fiber filling ratio of 87.0%.

A nozzle tip 11 having a major axis / minor axis ratio of 4.1 of a molten glass nozzle hole as shown in FIG. 3 is set so that the long side of the nozzle tip is perpendicular to the longitudinal direction of the nozzle plate 17 as shown in FIG. 256 nozzle hole walls without nozzle hole wall notches are arranged so as to face each other, and a cooling fin 5 is attached between rows of nozzle hole wall notches facing each other, and spinning is performed at 1190 ° C. and 2000 m / min. (See FIGS. 12 and 15).
The spun flat glass fiber was wound up by a winder 25 having a rotation axis parallel to the longitudinal direction of the nozzle plate. The flat glass fiber obtained had a flatness ratio of 4.3 and a flattening efficiency of 104.9, and there was little variation. In FIG. 15, reference numeral 22 denotes a water cooling unit to which the cooling fins 21 are attached, 23 denotes a sizing agent coating device, and 24 denotes a sizing roller. In this embodiment, the nozzle tip provided with the hot water reservoir is used, but even a nozzle tip without this can be used as long as it has a nozzle hole wall notch.

Comparative Example 2

  As shown in FIG. 11, the long side of the nozzle tip 11 used in Example 5 is parallel to the longitudinal direction of the nozzle plate 17 and the nozzle hole wall 15 without the nozzle hole wall notch is directed in the same direction. The cooling fins 21 were mounted individually, both ends of the major axis were cooled, and spinning was performed at 1190 ° C. and 2000 m / min. The positional relationship between the nozzle plate and the winder 25 was the same as in Example 6. The flat glass fiber obtained had a flatness ratio of 3.5 and a flattening efficiency of 68.0%, but the variation was large.

The long sides of the nozzle tip 11 used in the fifth embodiment are arranged 180 pieces at right angles to the longitudinal direction of the nozzle plate having the same size as the nozzle plate 17 of the fifth embodiment, and the cooling fins 5 are arranged along the short direction. Attachment was performed between the chips 11 and spinning was performed at 1190 ° C. and 2000 m / min. The positional relationship between the nozzle plate and the winder was the same as in Example 5. The flat glass fiber obtained had a flatness ratio of 4.1, and there was little variation.
Manufacture of glass fiber nonwoven fabric

1) Preparation of non-woven fabric The fiber obtained by cutting the flat glass fiber produced in Example 1 into a length of 13 mm is dispersed in water containing 50 ppm of polyethylene oxide as a fiber dispersant so as to have a concentration of 0.4 g / liter. Paper making was performed so that the amount was 20 g / m ² .
Epoxy resin emulsion (EN0270 manufactured by Dainippon Ink Co., Ltd.) and epoxy silane coupling agent γ-glycidoxypropyltrimethoxysilane (Nihon Unicar Co., Ltd. A-) 187) was prepared, impregnated to a solid content of 4% by weight, and dried with hot air at 150 ° C. to obtain a nonwoven fabric.

2) Preparation of laminated board This nonwoven fabric was impregnated with the following resin and dried to prepare a prepreg. Composition of epoxy resin varnish, Epicoat 5046-B-80 100 parts by weight (manufactured by Yuka Shell Epoxy)
-Epicoat 154 20 parts by weight (Oilized Shell Epoxy)
Dicyanamide 4 parts by weight Benzyldimethylamine 0.2 parts by weight Dimethylformamide 30 parts by weight Methyl ethyl ketone 15 parts by weight Ten prepregs are laminated, 18 μm copper foil is laminated on both sides, and the temperature is 170 ° C. and the pressure is 50 kg / cm ² . The laminate was pressed for a test piece of laminate.

3) Characteristic measurement Since various physical properties were measured about the glass fiber used for said process, the nonwoven fabric created from it, and the test body obtained from the nonwoven fabric, the result is shown in Table 1.
Here, the measurement method is as follows.

Measurement of fiber diameter and cross-sectional area of glass fiber:
The glass fiber cross section was calculated from the electron micrograph by computer image processing to calculate and calculate the ratio of the short diameter, the long diameter, the glass fiber cross sectional area, and the circumscribed rectangle area.
Tensile strength of nonwoven fabric: Conforms to JIS R-3420 5.4.
Measurement of specimen:
The copper foil was removed from the test laminate by etching, and the following measurements were performed on the subsequent laminate.
Resin content: According to JIS R-3420 5.3.
Surface smoothness: JIS B-0601 “Surface roughness measurement method”
[Draw 6 lines in a “rice” shape on the sample surface of 100 cm ² , make 10 lengths at 10 locations on each line (total of 60 locations), 10 mm, universal shape measuring machine (manufactured by Kosaka Laboratory Co., Ltd.) And trade name SEF-1A). ]
C) Linear expansion coefficient: According to JIS K-7197.

  A nonwoven fabric was prepared under the same conditions as in Example 7 except that the binder solution was impregnated so as to have a solid content of 6% by weight, and the nonwoven fabric was used under the same conditions as in Example 7. A specimen was obtained. The results are also shown in Table 1.

  As a high flat glass fiber, the flatness ratio is 4, the filling rate is 94%, the converted fiber diameter is 13 μm, the length is 13%, the glass fiber is 60% by weight, the flatness ratio is 4, the filling rate is 94%, and the converted fiber Nonwoven fabric under the same conditions as in Example 7 except that 40% by weight of glass fiber having a diameter of 8 μm and a length of 13 mm was used and the adhesive solution was impregnated so that the solid content was 6% by weight. In addition, a test body was obtained using the nonwoven fabric under the same conditions as in Example 7. The results are also shown in Table 1.

Comparative Example 3

  Glass fiber having an elliptical cross section with a flatness ratio of 4 and a filling rate of 75%, a converted fiber diameter of 10 μm, and a length of 13 mm is used, and the adhesive solution is made to have a solid content of 6% by weight. A nonwoven fabric was prepared under the same conditions as in Example 7 except that the impregnation was performed. An attempt was made to produce a prepreg using this non-woven fabric, but the strength of the non-woven fabric was weak. When trying to run a non-woven fabric impregnated with resin, the non-woven fabric was cut, and it was determined that actual production was impossible. Inevitably, a prepreg was prepared using the same resin as in Example 7 while the nonwoven fabric was allowed to stand, and a test laminate was prepared using the prepreg under the same conditions as in Example 7. The results are also shown in Table 1.

Comparative Example 4

  In Comparative Example 3, a nonwoven fabric was prepared under the same conditions as in Example 7 except that the solid content of the adhesive was 10% by weight, and a test specimen was obtained under the same conditions as in Example 7 using the nonwoven fabric. . The results are also shown in Table 1.

Comparative Example 5

Two types of glass cloth shown in Table 2 were prepared, and each was impregnated with the same resin as in Example 7 and dried to prepare a prepreg.
Each prepreg was laminated, 18 μm copper foil was laminated on both sides thereof, and pressed at a temperature of 170 ° C. and a pressure of 50 kg / cm ² for 60 minutes to obtain a laminate specimen. The test body was measured in the same manner as in Example 7. The results are also shown in Table 2.

As is clear from Table 1, when the glass fibers having the high flat cross section of Examples 7 to 9 are used, the binder is less than when the glass fibers having the elliptical approximate cross section shown in Comparative Examples 3 and 4 are used. We were able to create a non-woven fabric with high bulk density that had the strength required for prepreg production. In addition, the laminates prepared in Examples 7 to 9 had a lower resin content (higher glass fiber content) than those of Comparative Examples 3 and 4, and were extremely excellent in surface smoothness. In the comparison of Examples 7 to 9, Example 7 in which different converted fiber diameters were blended had a higher glass fiber content and excellent surface smoothness than other cases, and was excellent as a laminate. Had the characteristics.
Furthermore, as can be seen from the comparison between Tables 1 and 2, the laminates prepared in Examples 7 to 9 are superior in surface smoothness compared to the laminates using glass cloth, and the glass fibers. It was inferior in content.

As is clear from the above explanation, the flat glass fiber nonwoven fabric of the present invention has a flatness ratio of 2.0 to 10, preferably 3.1 to 8, a filling rate of 85% or more, preferably 90% or more, and Since a special high flat glass fiber that is preferably 93 to 98% is used, the bulk density of the nonwoven fabric can be increased and the adhesion effect by the binder can be enhanced, and the binder amount is about 3 to 8% by weight. The required tear strength can be ensured while adopting a low concentration of the resin and the nonwoven fabric is thin, and the surface smoothness is also excellent. For this reason, the flat glass fiber nonwoven fabric of the present invention can be suitably used as a reinforcing material for printed wiring boards, and can be used in place of glass cloth on the surface of printed wiring boards that could only use glass cloth until now. It can replace with a glass cloth and can be used also for the copper foil sticking surface in a multilayer printed wiring board.
The printed wiring board produced using the flat glass fiber nonwoven fabric of the present invention can increase the glass fiber content in the substrate as compared with the conventionally used glass fiber nonwoven fabric, and thus the heat resistance of the printed wiring board. And the coefficient of thermal expansion decreases, warping and twisting decrease, and the amount of binder used is as small as 3 to 8% by weight, so that the surface of the glass fiber and the matrix resin by the surfactant contained in the binder Can be suppressed to a small extent, and hot water resistance and heat resistance are not deteriorated. In addition, since the flat glass fiber nonwoven fabric can be thinned, the printed wiring board can be thinned, and characteristics comparable to those using glass cloth can be exhibited. In addition, since the flat glass fiber nonwoven fabric can be manufactured at a lower cost than a glass cloth, the cost of the printed wiring board can be reduced.

Furthermore, in the printed wiring board using the flat glass fiber nonwoven fabric of the present invention on the copper foil bonding surface, the surface smoothness of the copper foil bonding surface is equal to or higher than that using glass cloth, so that circuit formation by etching is performed. Is reliably performed, and a highly reliable printed wiring board can be obtained. In addition, the thickness of the copper foil to be attached to the surface can be reduced, the width of the circuit formed by etching the copper foil can be further narrowed and densified, the thickness of the printed wiring board, In particular, the thickness of the multilayer board can be further reduced and the performance can be improved.
In addition, since the glass fiber spinning nozzle tip of the present invention is notched on one side in the major axis direction of the nozzle hole provided in the nozzle portion, the molten glass flows so as to stick to the remaining nozzle tip inner surface due to surface tension. Then, since one side of the flowing glass is in contact with air, cooling is also promoted, and the viscosity of the surface is higher than that of the molten glass flowing out from the conventional nozzle tip, and the flattening efficiency is increased against the force of rounding. In the case of a normal nozzle tip, when the viscosity increases in this way, it is difficult for the molten glass to flow out of the nozzle hole, and the production volume decreases, but when the nozzle tip of the present invention is used, Since the viscosity of molten glass remains low and the viscosity rises while flowing through a nozzle section that has no nozzle hole wall on one side, this is not the case, and the stability of the cross-sectional shape and flattening efficiency are lower than before. Can be increased dramatically.

Further, by providing a molten glass pool at the upper part of the nozzle portion, it is possible to further stabilize the high-speed spinning of flat glass fibers. Even in a normal nozzle tip, the viscosity of the molten glass inside increases due to the cooling effect. However, the nozzle tip of the present invention is provided with a molten glass reservoir portion in which the inflow side area of the nozzle hole is 1.5 times larger than the outflow side area As a result, the glass flow inside the nozzle tip is less likely to be disturbed, the viscosity of the glass rises along the inner surface of the nozzle tip, and the molten glass has a high viscosity at the outer periphery of the cross section when it exits the nozzle hole. Since the glass having a low viscosity is sandwiched between the molten glass planes with high viscosity, the force to return to the circular cross section due to the surface tension is weakened and the cross-sectional shape is stabilized. Since this flows out and flows down the nozzle portion having a notch, the above-described flat glass fiber can be spun at a high speed.
In addition, the nozzle hole is shaped like a rectangle or dumbbell, and if necessary, grooves or convex edges are attached, making it possible to efficiently produce highly flat cross-section glass fibers with a stable filling rate of 85% or more. Can be produced.
Further, according to the present invention, since the shapes of the nozzle tip, nozzle hole, and molten glass pool are simplified, general machining is possible, and there is an economic advantage that the manufacturing cost of the nozzle plate is low.

  In the nozzle plate of the present invention, the longitudinal direction of the nozzle plate and the major axis direction of the nozzle hole in the nozzle tip are arranged orthogonally, and cooling fins can be used between the nozzle tip rows, so that cooling is uniform and cooling There is little difference in the cross-sectional shape of the fiber due to the difference. Further, when the longitudinal direction of the nozzle plate is arranged at a position parallel to the rotation axis of the sizing agent coating apparatus and / or the rotation axis of the winder, the solvent glass spun from the nozzle chips arranged on the nozzle plate is in the long side direction of the nozzle chip. Therefore, the angle between the nozzle tip at the end of the plate long side and the point where the fibers are converged is small, and the direction toward the center of the nozzle plate is not the long side direction of the nozzle tip but the short side direction. Therefore, the angle pulled to the center of the molten glass on the lower surface of the nozzle hole is inevitably reduced, and the cross-sectional shape of the fiber spun from the nozzle tip near the end of the long side of the plate is also spun from the nozzle tip in the center. The cross-sectional shape of the finished fiber is almost unchanged. Therefore, by using the nozzle plate of the present invention and its arrangement method, a high flat glass fiber having a uniform flat ratio can be obtained at high speed and stably.

  Also, in the process of spinning flat glass fiber, the wall surface with the nozzle hole wall notch in the nozzle tip faces each other, and the nozzle hole walls without the notch part face each other at the same time. If the cooling fins are arranged only between the wall surfaces with the notches, the surface with the nozzle hole wall notches is cooled strongly, and the molten glass flowing through the nozzle holes of the nozzle tip has a surface tension at the notches. Resulting in a decrease. On the other hand, since the nozzle hole wall portion without the notch is less cooled, the temperature of the wall surface rises. In addition, since no cooling fin is provided between the surfaces, the distance can be narrowed at least by the thickness of the cooling fin. As a result, the cooling is further suppressed, the temperature of the wall portion is increased, and it becomes possible to produce glass fibers having a high aspect ratio. Further, the nozzle chip installation area is reduced by the amount of the gap being narrowed, and the number of holes can be increased with respect to the nozzle plate having the same area.

  Furthermore, the nozzle chip for spinning a high flat glass fiber including a protruding nozzle part and at least one set of nozzle holes penetrating the nozzle part, the nozzle hole wall on the nozzle chip wall surface side of the nozzle hole wall in the major axis direction Is a flat glass having a concave nozzle hole wall notch in the cross section and each nozzle hole being arranged so that the nozzle hole walls in the long diameter direction without the concave nozzle hole wall notch in the cross section are continuous with each other The nozzle tip for fiber spinning has a structure in which the long diameter part and / or the short diameter part of the nozzle hole wall without the notch and the corresponding part of the other nozzle chip are connected without a gap, so that the above-described effects are further exerted. Is done.

In FIG. 1, (a) and (b) are schematic cross-sectional views showing examples of the cross-sectional shape of the flat glass fiber used in the present invention. FIG. 2 is a schematic cross-sectional view for explaining how to measure the cross-sectional dimensions of the flat glass fiber. FIG. 3 is a perspective view showing one embodiment of a nozzle tip having a molten glass reservoir of the present invention. FIG. 4 is a longitudinal sectional view taken along line X-X ′ in FIG. 3. FIG. 5 is a plan view of the nozzle tip of FIG. 3 as viewed from below. FIG. 6 is a perspective view of a nozzle chip in which the length of the nozzle hole wall notch is not 100% as an example of the nozzle chip having no molten glass reservoir of the present invention. Here, 17 represents a nozzle plate. FIG. 7 shows a nozzle chip for spinning a high flat glass fiber including a pair of nozzle holes, and the nozzle hole wall on the nozzle chip wall surface side of the nozzle hole wall in the major axis direction has a concave nozzle hole wall in cross section. A nozzle plate for spinning a high flat glass fiber is provided from the bottom, which is provided with a notch and each nozzle hole is arranged so that the nozzle hole wall in the long diameter direction without the concave nozzle hole wall notch in the cross section is continuous with each other. FIG. FIG. 8 is obtained by connecting two nozzle chips of FIG. 7 (having two sets of nozzle holes), and there is no gap between the two nozzle chips, and the nozzle can be miniaturized. The greater the number of connections, the greater this effect. In FIG. 9, (a) is a partial plan view seen from the bottom of an embodiment of the nozzle plate of the present invention, and (b) is a partially enlarged view for explaining the arrangement relationship of the nozzle chips. Cooling fins are arranged between the facing notches. In FIG. 10, (a) is a partial plan view of another embodiment of the nozzle plate of the present invention viewed from below, and (b) is a partially enlarged view for explaining the arrangement relationship of the nozzle tip wall portions. Cooling fins are disposed between the nozzle walls facing each other. In FIG. 11, (a) is a partial plan view seen from the bottom of an example of a nozzle plate whose notch is parallel to the longitudinal direction, and (b) is a partially enlarged view for explaining the arrangement relationship. FIG. 12 is a side view showing the relationship between the nozzle tip and the cooling fin of the present invention. FIG. 13 is an imaginary view of a flat glass fiber spun using the nozzle plate of the present invention in a randomly focused state as conventionally expected. FIG. 14 is a partially enlarged view of an actual converged state of flat glass fibers spun using the nozzle plate of the present invention. FIG. 15 is a schematic front view of a spinning device using the nozzle plate of the present invention. Here, 22 is a water cooling unit, 23 is a sizing agent coating device, 24 is a sizing roller, and 25 is a winder. In FIG. 16, (a) is a plan view seen from below explaining the relationship between the nozzle plate and the cooling fin of the present invention, (b) is a front view of the main part of a spinning device using this, (c ) Is an explanatory view of the flow of molten glass from the nozzle tip at the center and end of the nozzle plate. In FIG. 17, (a) is a bottom view for explaining the relationship between the nozzle plate and the cooling fin, (b) is a front view of the main part of a spinning device using the same, and (c) is a central portion of the nozzle plate. It is explanatory drawing of the flow of the molten glass from the nozzle tip of an edge part. FIG. 18 is a cross-sectional view showing another aspect of the nozzle tip of the present invention.

Claims (3)

A highly flat glass fiber having a flat cross section, the flatness ratio of the cross section is 3.1 to 8, the filling rate is 90 to 98% or more, and the converted fiber diameter is 5 to 17 μm. Two types of high flat glass fibers having different fiber diameters, the converted fiber diameters of the two types of high flat glass fibers being different by 5 to 10 μm and high flat glass fibers having a large converted fiber diameter being 90 to 50 weight %, 2 types of high flat glass fibers blended with 10-50 wt% of small high flat glass fibers are included at 90 wt% or more of the weight of the nonwoven fabric excluding the binder, and the amount of the binder is 3-8 wt%. A glass fiber nonwoven fabric characterized by A printed wiring board using one or more layers of the glass fiber nonwoven fabric according to claim 1 . A printed wiring board using the glass fiber nonwoven fabric according to claim 1 on a copper foil bonding surface.