Manufacturing methods of glass yarn and glass cloth and glass cloth

Abstract

The purpose of this invention is to provide a glass cloth with fewer defects, a method for manufacturing the same, and the glass yarn constituting the glass cloth. The glass cloth of the present invention is woven from glass yarn containing a plurality of glass filaments as warp and weft yarns. Taking a length of 500 m as the object, white LED light is irradiated along the surface of the glass cloth, and observation is made every 1 m along the length. When there is a whole surface of fuzz on the cloth surface, it is counted as 1 defect. At this time, the defect rate is 0 to 3.5% as expressed by the following formula. Defect rate (%) = (Total number of defects / 500) × 100

Description

[Technical Field]

[0001] This invention relates to a method for manufacturing glass yarn and glass cloth, and the glass cloth. [Previous Technology]

[0002] In recent years, with the development of the information and communication society, data communication and / or signal processing have become increasingly high-capacity and high-speed. Printed circuit boards are used in high-end servers, high-end routers / switches, supercomputers, base station communication equipment, measuring instruments, etc., and printed circuit boards are moving towards lower dielectric constants. Therefore, a low-dielectric glass cloth has been proposed for the glass cloth constituting the printed circuit board. For example, Patent Document 1 discloses the following principle: compared with the E glass cloth that has been used since the past, more boron trioxide (B2O3) is added to the glass composition, and the amount of other components such as silicon dioxide (SiO2) is adjusted, thereby achieving a low dielectric constant of the glass cloth.

[0003] Regarding terminal electronic devices such as smartphones, there is a demand for high-capacity and high-speed communication. Therefore, the use of low-dielectric printed circuit boards (PCBs) for smartphone applications has been expanding in recent years. Consequently, the demand for thinner (e.g., 10–50 μm thick) low-dielectric glass cloths is becoming increasingly strong. [Prior Art Documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. Hei 11-292567 [Patent Document 2] Japanese Patent Application Publication No. 2013-112917 [Patent Document 3] Japanese Patent Application Publication No. 2004-115351 [Patent Document 4] Japanese Patent Application Publication No. 2011-140721 [Patent Document 5] International Publication No. 2018 / 216637 [Summary of the Invention]

[0005] [The problem the invention aims to solve]

[0006] The inventors conducted research and found that, compared with previously known E-glass cloth, the low-dielectric glass cloth described in Patent Document 1 differs in performance or quality. In particular, in the case of low-dielectric glass cloth with a thickness of 10 to 50 μm, the quality of the fibers tends to vary greatly, making it difficult to consistently obtain glass cloth with excellent fiber quality.

[0007] As a method to improve the bristle quality of glass fabrics, Patent Literature 2 and 3 reveal a method of using a specific starch for the clustering agent of glass yarn, Patent Literature 4 reveals a method to ease the bending of the yarn in the steel wire loop in glass yarn fabrication, and Patent Literature 5 reveals a method of using a specific composition for low dielectric glass.

[0008] Patent literature 2 reveals the following subject matter: the fluffing of the cloth is inhibited by using the following glass yarn to manufacture glass cloth, which is produced using a clustering agent containing 25 to 100 mass% of amylose starch and the average particle size of the starch is less than 12 μm.

[0009] Patent literature 3 reveals the following theme: by preparing the following glass yarn to improve the clustering of the glass yarn, which can effectively prevent the production of hair feathers, the glass yarn is attached with 1.5 to 3.0 mass% of an etherified high amylose starch containing more than 50% of amylose.

[0010] Patent literature 4 reveals the following subject matter: in the yarn step in glass yarn manufacturing, the yarn passing part of the steel wire ring is made thicker, and the bending of the yarn when passing through the steel wire ring is smooth, thereby not easily producing hair feathers, broken yarns, coils and other quality defects.

[0011] Patent literature 5 reveals the following situation: by forming the following low dielectric glass can inhibit yarn breakage or fluffing during glass yarn processing, the low dielectric glass contains 50≦SiO2≦56,20≦, in the glass composition B2O3≦30, 10≦Al2O3≦20, 3.5≦MgO+CaO≦10, and 0≦R2O≦1.0 (in the formula, R is selected from at least one element from Li, Na, and K), thereby containing Fe2O3.

[0012] The presumed reason is that the strength of the low dielectric glass yarn is weaker than the glass yarn of E glass which has been used since prior, but the status quo is that the glass fabric manufactured using the low dielectric glass yarn available in the market has not been obtained so far as the low dielectric glass yarn that can stably obtain high quality glass fabric has been obtained.

[0013] For example, by using glass yarn with fewer defects, it is easy to achieve quality improvement of glass cloth. In recent years, with the improvement of the quality required for glass cloth, it is expected to provide a glass cloth that can meet this quality improvement expectation. As an example, low dielectric resins have a tendency to become higher in molecular weight or have a tendency to have bulky functional groups, thereby there is a possibility that the impregnancy of the varnish is less favorable than that of the previous resin, so the glass fabric exists in the background of demanding impregnancy.

[0014] This invention was made in view of the above-mentioned problems, and its object is to: provide a glass yarn with fewer defects; provide a glass cloth with high uniformity and good quality using the glass yarn; and even provide a method for manufacturing it. [Technical means to solve the problem]

[0015] The inventors and others have carried out a keen study to solve the above problems, resulting in the completion of the invention by focusing on situations such as the detection of tiny hair feathers only by the prescribed visual observation. The following enumerates one form of the invention. [1] A glass cloth in which a glass yarn containing a plurality of glass filaments is used in warp and weft yarns for weaving, and a white LED (light emitting diode, emitting secondary body) light is irradiated along its cloth surface with a length of 500 m as the object of the said glass cloth, and each m ground to observe, in the case of the presence of whole surface hairs on the above fabric surface, the count is the number of defects 1. In this case, the defect rate represented by the following formula is 0 to 3.5%. Defect rate (%) = (total of count values ​​of defects / 500) × 100 [2] The glass cloth as noted in item 1, where the above-mentioned entire surface of the hair plumes contains 200–1000 μm of fluff observed on the above-mentioned fabric surface using an optical microscope due to the breakage of the above-mentioned filaments. [3] The glass cloth as described in items 1 or 2, wherein the thickness of the said glass cloth is 10–50 μm. [4] The glass cloth as described in any one of items 1 to 3 contains the above-mentioned glass yarn that satisfies the following conditions: (i) Tesco (TEX) is 1–13, (ii) breaking strength is 0.50–0.80 N / tex, and (iii) the number of filaments that occur more than 2 times the average value of the yarn width at 180 m determination is less than 3 filaments. [5] The glass cloth as described in any one of items 1 to 4, which contains the said glass yarn with an add-on spacing length of 1.8 to 10.0 cm. [6] For the glass fabric as noted in any of items 1 to 5, the difference between the maximum value and the minimum value of the length of the pinning interval containing the above-mentioned glass yarn is divided by the average value of the length of the pinning interval (the pinpointing spacing length difference index) of the above glass yarn below 0.7. [7] As described in any one of items 1 to 6 of the glass cloth, wherein the above-mentioned glass yarn having a length of more than 10,000 m is the subject, the number of filaments in which a slip of more than 2 times the average value of the yarn width occurs in each of the assay ranges of the above 5 parts when selecting a determination range of 180 m in the length direction at five sites that are different from each other is less than 3. [8] As noted in any one of items 1 to 6 of the glass cloth, wherein the above-mentioned glass yarn having a length of more than 50,000 m is the subject, when a determination range of 180 m in the length direction is selected at seven sites that are different from each other, the number of filaments in which slippage more than 2 times the mean value of the yarn width occurs in each of the ranges of the above 7 sites is less than 3.[9] As described in any one of items 1 to 6 of the glass cloth, wherein the above-mentioned glass yarn having a length of more than 100,000 m is the subject, when a determination range of 180 m in the length direction is selected separately at 10 sites that are different from each other, the number of filaments that slip more than 2 times the average value of the yarn width occurs in each of the ranges of the above 10 sites is less than 3.

[10] A method for the manufacture of glass cloth, which comprises the step of weaving by using a glass yarn containing multiple strands of glass filament for warp and weft yarns, and (i) the tex of the said glass yarn is 1 to 13, (ii) the breaking strength of the said glass yarn is 0.50 to 0.80 N / tex, and (iii) the above 2 times the average of the yarn width sliding occurs at 180 m determination.

[11] The method of fabrication of glass cloth as described in item 10, wherein the tex of the above glass yarn is 1 to 7.

[12] The method of fabrication of glass cloth as described in items 10 or 11, wherein the number of single glass filaments constituting the above glass yarn ranges from 30 to 120.

[13] The method of manufacturing the glass cloth as described in any one of items 10 to 12, wherein the length of the splint spacing of the above glass yarn is 1.8 to 10.0 cm.

[14] The method of fabrication of glass cloth as described in any of items 10 to 13, wherein the difference between the maximum and the minimum of the length of the splint interval for the above-mentioned glass yarn is divided by the average of the length of the splint (spring length difference index) is less than 0.7.

[15] The method of fabrication of glass cloth as described in any one of items 10 to 14, wherein the density of the said glass yarn is more than 2.2 g / cm3 and less than 2.5 g / cm3.

[16] The method of fabrication of glass cloth as described in any one of items 10 to 15, wherein the elastic coefficient of the above glass yarn is 50 to 70 GPa.

[17] The method of fabrication of glass cloth as described in any one of items 10 to 16, wherein the elastic coefficient of the above glass yarn is 50 to 63 GPa.

[18] As described in any one of items 10 to 17 of the manufacturing method of glass cloth, wherein the above-mentioned glass yarn having a length of more than 10,000 m is the subject, when a determination range of 180 m in the length direction is selected at five sites that are different from each other, the number of filaments in which slippage more than 2 times the average value of the yarn width occurs in each of the ranges of the above 5 sites is less than 3.

[19] As described in any one of items 10 to 17 of the manufacturing method of glass cloth, wherein the above-mentioned glass yarn having a length of more than 50,000 m is the subject, when a determination range of 180 m in the length direction is selected at seven sites that are different from each other, the number of filaments in which slippage more than 2 times the average value of the yarn width occurs in each of the ranges of the above 7 sites is less than 3.

[20] As described in any one of items 10 to 17 of the manufacturing method of glass cloth, wherein the above-mentioned glass yarn having a length of more than 100,000 m is the subject, when a determination range of 180 m in the length direction is selected separately at 10 sites that are different from each other, in each of the ranges of the above

[21] A glass yarn in which (i) the tex is 1–13, (ii) the breaking strength is 0.50–0.80 N / tex, and (iii) the number of filaments that occur more than 2 times the average value of the yarn width at 180 m determination is less than 3 filaments.

[22] As recorded in item 21 of the glass yarn, where the above des are 1–7.

[23] The glass yarn as described in items 21 or 22, wherein the number of single glass filaments constituting the said glass yarn ranges from 30 to 120.

[24] The glass yarn as described in any one of items 21 to 23, wherein the length of the splint spacing is 1.8–10.0 cm.

[25] For glass yarns as noted in any of items 21 through 24, the value obtained by the difference between the maximum and the minimum of the length of the splint interval divided by the average of the length of the splint interval (index length difference index) is less than 0.7.

[26] The glass yarn as described in any one of items 21 to 25 has a density of more than 2.2 g / cm3 and not reaching 2.5 g / cm3.

[27] The glass yarn as described in any one of items 21 to 26, where the elasticity coefficient is 50–70 GPa.

[28] The glass yarn as described in any one of items 21 to 27, where the elasticity coefficient is 50–63 GPa.

[29] The glass yarn as described in any of items 21 to 28, wherein the above-mentioned glass yarn having a length of more than 10,000 m is the subject, when a determination range of 180 m in the length direction is selected at five sites that are different from each other, the number of filaments that slip more than 2 times the average value of the yarn width occurs in each of the ranges of the above 5 sites is less than 3.

[30] As described in any one of items 21 to 28, in which the above-mentioned glass yarn having a length of more than 50,000 m is the subject, when a determination range of 180 m in the length direction is selected separately at seven sites that are different from each other, the number of filaments in which slippage more than 2 times the mean value of the yarn width occurs in each of the ranges of the above 7 sites is less than 3.

[31] As described in any one of items 21 to 28, in which the above-mentioned glass yarn having a length of more than 100,000 m is the subject, the number of filaments in which slippage of more than 2 times the average of the yarn width occurs in each of the assay ranges of the above [Effect of the invention].

[0016] According to the present invention, it is possible to provide glass yarn with fewer defects, and it is also possible to use the glass yarn to provide glass cloth with high uniformity and good quality, and furthermore, it is also possible to provide a method for manufacturing it.

Implementation Method

[0017] Hereinafter, the implementation of the present invention (hereinafter referred to as "implementation method") will be described in detail, but the present invention is not limited thereto and various modifications can be made without departing from its spirit.

[0018] [Glass cloth] The first embodiment of the present invention is glass cloth.

[0019] The glass cloth of this embodiment is woven from glass yarn containing a plurality of glass filaments (hereinafter also referred to as "filaments") as warp and weft yarns. A predetermined measurement length of 500 (m) along the entire length of the glass cloth is used as the object. White LED light is shone along the cloth surface for every 1 m along the length direction and observed. When the cloth surface has a full-surface fuzziness, it is counted as a defect number 1. In this case, the defect rate, expressed by the following formula, is 0 to 3.5%. Defect rate (%) = Total count of full-surface fuzziness / 500 (m) × 100

[0020] In this embodiment, by observing the fabric surface by illuminating it with white LED light along the fabric surface, it is possible to detect filament breaks (hereinafter also referred to as "micro-hairs") with a length of less than 1 mm with better sensitivity compared to the previous observation by illuminating light in a direction perpendicular to the fabric surface. Moreover, the defect rate derived from this detection method is 0 to 3.5%, so there are fewer defects for glass cloth, and even various properties are excellent. From the same point of view, the defect rate is preferably 3.0% or less, and more preferably 2.9% or less. Furthermore, the previous observation (the previous observation by illuminating light in a direction perpendicular to the fabric surface) did not assume the observation of micro-hairs. Therefore, in the case of the previous observation method, it is not possible to detect micro-hairs as assumed in this embodiment with good sensitivity, and it is even difficult to think of controlling the defect rate within the numerical range assumed in this embodiment. The method for calculating the "defect rate (%)" will be described in detail in the embodiments.

[0021] The entire surface of the fabric is characterized by fuzz of 200 to 1000 μm caused by filament breakage, which can be observed on the fabric surface using an optical microscope. In this embodiment, this type of entire surface of the fabric is easily observed by illuminating the fabric surface with white LED light.

[0022] The glass cloth of this embodiment preferably has the thickness described later. Furthermore, the glass yarn used to obtain the glass cloth of this embodiment preferably has the structure described later.

[0023] (Dielectric constant of glass cloth) The dielectric constant of the glass cloth at a frequency of 10 GHz is preferably 5.0 or less, more preferably 4.9 or less, further preferably 4.8 or less, and especially preferably 4.6 or less. The dielectric constant of the glass cloth can be determined by the cavity resonance method. In this specification, unless otherwise specified, the dielectric constant of the glass cloth refers to the dielectric constant at a frequency of 10 GHz.

[0024] [Glass yarn] The second embodiment of the present invention is glass yarn.

[0025] The glass yarn system of the second embodiment has (i) a tex of 1 to 13, (ii) a breaking strength of 0.50 to 0.80 N / tex, and (iii) a number of filaments slipping off more than twice the average yarn width when measured at 180 m (hereinafter, "the number of filaments slipping off more than twice the average yarn width when measured at 180 m" is also referred to as "slipping filaments") of 3 or less.

[0026] Compared to the previous E-type glass cloth, the glass cloth manufactured using low-dielectric glass yarn exhibits differences in quality. Therefore, it is difficult to consistently obtain high-quality low-dielectric glass cloth. In particular, a detailed study of glass cloths with relatively poor quality revealed a greater number of "ribbon-like fuzzy defects" in low-dielectric glass cloths manufactured from low-dielectric glass yarn with a slippage filament count exceeding a specific range. These "ribbon-like fuzzy defects" are characterized by densely packed fuzz in a ribbon-like pattern along the length direction. In contrast, this embodiment is based on the understanding that by using low-dielectric glass yarn with filament slippage within a specific range, this defect in the low-dielectric glass cloth can be reduced. This reason is not bound by theory, but it can be assumed that glass yarn with a filament shedding exceeding a certain value (e.g., more than 3 slipped filaments) is subject to interference with weaving components when it passes through weaving components such as the annular guide after unwinding from the bobbin. At this time, the filament shedding is likely to increase or the filaments will break.

[0027] In particular, the weft yarn is conveyed along the yarn path from unwinding from the bobbin to being ejected, accompanied by an expansion motion. Therefore, it can be considered that the slippage of the filaments is easily subjected to shear stress and cut, and the cut filaments become entangled due to the rotational motion, thus easily growing into coarse fuzz. In order to improve productivity, the weft yarn weaving speed is preferably faster, but it is believed that the faster the weft yarn conveying speed, the greater the increase in filament slippage or filament breakage.

[0028] The E-glass yarn previously used has a higher density and greater strength compared to low-dielectric glass yarn. Therefore, the handling of the glass yarn is more stable, and the degree of interference with the weaving components is less, thus limiting the damage that may occur during interference. On the other hand, the lighter and weaker low-dielectric glass yarn tends to oscillate more during handling due to tension variations. Therefore, it is more prone to interference with the weaving components, and when interference occurs, it is more likely to suffer greater damage. Therefore, it is believed that this can easily increase filament shedding or filament breakage.

[0029] Furthermore, when glass yarn with filament shedding exceeding a certain range is subjected to physical loads such as high-pressure water spraying during the fiber opening process, the shedding area is prone to movement. Therefore, it is believed that the shedding area is easily subjected to loads such as interference with the glass cloth conveying components, thereby easily generating fuzz or fuzzing at the breakage point due to filament breakage, starting from the shedding point. For the purpose of improving the in-plane uniformity and impregnation of the glass cloth, a stronger fiber opening processing force is preferable. However, it is believed that the stronger the fiber opening processing force, the more likely it is to generate more fuzz defects caused by filament breakage or coarse fuzz defects caused by filament entanglement.

[0030] Furthermore, the low-dielectric glass yarn, which has a lower density and weaker strength compared to E-glass, experiences a significant decrease in glass strength during the heat cleaning process. Therefore, it is believed that when the fiber opening step is performed after the heat cleaning step, it will be severely damaged by physical loads such as high-pressure water spray, making it more prone to fuzzing due to filament breakage or pilling of broken filaments. It is believed that these effects will manifest in the form of glass cloth quality.

[0031] On the other hand, by using the glass yarn of this embodiment, even when using a lighter and weaker glass yarn that has undergone low dielectric transformation, damage caused by interference with weaving components such as annular guides during the weaving process can be reduced. Furthermore, when using the glass yarn of this embodiment, the degree of interference between the detached parts and the conveying components, or the damage caused by interference, can be reduced during the fiber opening process. Therefore, by using the glass yarn of this embodiment, fuzzing caused by filament breakage during the weaving and fiber opening processes can be suppressed, thereby obtaining a uniform glass cloth of good quality. Moreover, by using the aforementioned glass yarn, there is a tendency to increase the weaving speed (the speed at which the glass yarn is woven in) and / or the fiber opening processing force during the fiber opening process, which is therefore preferable.

[0032] When using the glass yarn of this embodiment, there is a tendency that during the process of unwinding the original yarn from the bobbin and combining the glass yarn (e.g., warp yarn) on the yarn frame, it is possible to prevent defects such as fuzzing caused by friction at the yarn guide or other components, thus enabling production with good quality and stability; therefore, it is preferable. Furthermore, by using the aforementioned glass yarn, there is a tendency to increase the warping speed, which is also preferable.

[0033] (Texas of glass yarn) The tetras of the glass yarn are 1 to 13, preferably 1.5 to 12, more preferably 2.0 to 11, and even more preferably 2.5 to 10, or 1 to 7. If the tetras of the glass yarn are 13 or less, the strength of the glass yarn is weaker, and therefore the following tendency may occur: interference with weaving components such as the annular guide when the glass yarn is unwound during the weaving process, and interference with the glass cloth conveying components during the fiber opening process, resulting in poor fuzziness. On the other hand, by adjusting the degree of filament shedding to a specific range in this embodiment, the above-mentioned degree of interference or the damage caused by interference can be reduced, and as a result, high-quality glass cloth can be obtained stably. By setting the ts of the glass yarn to 1 or higher, when the degree of filament shedding is within a specific range of this embodiment, it is possible to suppress filament breakage when the glass yarn is unwound and passes through weaving components such as an annular guide during the weaving step, or when it interferes with the glass cloth conveying components during the fiber opening step.

[0034] (Breaking strength of glass yarn) The breaking strength of glass yarn is 0.50 to 0.80 N / tex. A more preferred range of breaking strength is 0.53 to 0.79 N / tex, a more preferred range is 0.57 to 0.78 N / tex, and an even more preferred range is 0.60 to 0.77 N / tex. If the breaking strength of glass yarn is above the lower limit mentioned above, the filaments are less likely to break when subjected to shear stress due to interference with weaving components such as the annular guide after unwinding the glass yarn in the weaving step, or interference with the glass cloth conveying components in the fiber opening step. This reduces the likelihood of fuzz formation. On the other hand, if the breaking strength of glass yarn is below the upper limit mentioned above, the oscillation or expansion movement of the yarn is tended to be less during the yarn conveying process from unwinding the glass yarn from the bobbin until it is ejected. As a result, fuzz defects caused by increased filament shedding or filament breakage are less likely to occur. This phenomenon is presumed to be due to the flexibility of the glass yarn.

[0035] (Number of slipped filaments in glass yarn) The number of slipped filaments in glass yarn is 3 or less. The preferred range for the number of slipped filaments is 2 or less, more preferably 1 or less, and even more preferably 0.

[0036] The aforementioned "180 m" can be any of the following: 1) the length starting from the end (one end or the other end) of the glass yarn in the length direction; 2) the length of any part other than the end. As a specific example of 2) above, 2-1) a length set starting from a part 2 to 6 m (e.g., 5 m) away from the end in the length direction. If 2-1) is used, it will not be affected by the "loose yarn" that is easily generated at the end of the glass yarn, and the slippage filament count can be accurately measured in accordance with the purpose of this invention.

[0037] When the glass yarn is wound in a bobbin, "180 m" can be any of the following: 3) the length including at least a portion of the outermost or innermost circumference of the bobbin; 4) the length of any part other than the outermost and innermost circumferences. As a specific example of 4) above, from the point of view of ease of observation, examples can be: 4-1) the length set as the starting point of the second turn when the outermost circumference is set as the first turn; 4-2) the length set as the starting point of the second turn when the innermost circumference is set as the first turn. Alternatively, it can be 4-3) the length set at any part other than the aforementioned starting point.

[0038] When taking glass yarn with a length of 10,000 m or more as the object, and selecting a measurement range of 180 m in the length direction at 5 different locations, the number of slipped filaments in each of the 5 measurement ranges is preferably 3 or less, more preferably 2 or less, further preferably 1 or less, and most preferably 0.

[0039] Furthermore, when the glass yarn having a length of 50,000 m or more is used as the object, and a measurement range of 180 m in the length direction is selected at 7 different locations, the number of slipped filaments in each of the 7 measurement ranges is preferably 3 or less, more preferably 2 or less, further preferably 1 or less, and most preferably 0.

[0040] Furthermore, when the glass yarn having a length of 100,000 m or more is used as the object, and a measurement range of 180 m in the length direction is selected at 10 different locations, the number of slipped filaments in each of the 10 measurement ranges is preferably 3 or less, more preferably 2 or less, further preferably 1 or less, and most preferably 0.

[0041] When determining the slippage filament count, the glass yarn can be fed at a faster speed. The measurement can be performed simultaneously with the air unwinding and feeding of the glass yarn from the bobbin, similar to the weft yarn ejection process in weaving (in this case, a yarn guide should be appropriately installed to prevent the ejected glass yarn from becoming tangled). However, the slippage filament count is determined according to the method described in the embodiments.

[0042] By making the number of slip-off filaments below the above range and the breaking strength within the above range, during the carrying process of the glass yarn from the cylinder tube back-winding until ejection, enlarged filament shedding, filament breakage, or coarse hair plumes caused by entanglement of the broken filament are less likely to occur. This enables stable acquisition of high-quality glass cloth with fewer hair-dense parts. The reason for this is presumed to be that because the extent and frequency of filament slippage is small to within a certain range, the extent to which the slippage site produces interference or the resistance due to interference with woven parts such as toroidal guides becomes smaller.

[0043] In particular, as mentioned above, the weft yarn is susceptible to being cut, again, the cut filament sheets are susceptible to entanglement due to expansion motion. On the other hand, it is presumed that by adjusting the number of detached filaments within the above range, the filament cutting, or entanglement of the cut filament can be inhibited. Furthermore, it is presumed that the reason lies in the fact that the degree of interference with the transport member of the glass cloth or the resistance due to interference is reduced in the opening step because the extent and frequency of filament slippage is small to within a certain range.

[0044] The number of slipped filaments can be adjusted by using the following methods alone or in combination: ・A method of designing a bushing nozzle configuration in such a way that the filament ejected from multiple bushing nozzles is equal to one bundle when the filament ejected from multiple bushing nozzles is equal to one bundle during the spinning step of glass yarn fabrication;・Method of adjusting the nozzle shape of the bushing nozzle according to the difference between the distance from the nozzle to the cluster point mentioned above;・A method of adjusting the lateral movement of the silk cake during curling;・A method of adjusting the change in the number of pins per unit length to a specific range;

[0045] (Density of glass yarn) The density of glass yarn is preferably 2.2 g / cm3 or more and less than 2.5 g / cm3, more preferably 2.2 g / cm3 or more and less than 2.45 g / cm3, and further preferably 2.2 g / cm3 or more, 2.40 g / cm3 or less, and further preferably 2.2 g / cm3 or less.

[0046] If the density of the glass yarn does not reach 2.5 g / cm3, a situation exists that produces the following tendency: During the carrying process of the glass yarn from the cylinder tube back-winding until ejection, the swinging or expansion motion in the direction and perpendicular to the carrying direction is easily increased, thereby easily producing bad bristles due to interference with the loom parts. However, by adjusting the number of slipped filaments to within a specific range of this embodiment, it is possible to suppress the generation of hair feathers due to interference with the woven device, thereby, stably obtaining a high quality glass cloth.

[0047] Also, if the density of the glass yarn does not reach 2.5 g / cm3, there is a tendency to produce the following tendency: when subjected to physical loading such as high-pressure water spray pressure during the fiber opening step, the relaxation of the glass cloth becomes larger. However, by adjusting the number of slipped filaments to within a specific range in this embodiment, it is possible to suppress hair plumes due to interference with the transported member, thereby, stably obtaining a high quality glass cloth.

[0048] On the other hand, by making the density of the glass yarn 2.2 g / cm3 or more, the transport track of the glass yarn can be stabilized. Furthermore, by making the density of the glass yarn above 2.2 g / cm3, the relaxation of the glass cloth can be reduced. The density of the glass yarn can be found in the form of the density of a block glass of 1 cm3.

[0049] (Filament and diameter) Glass yarn is obtained by set of bundles of multiple strands of filament and twisting as necessary. In this case, the glass yarn is classified as complex glass filament and the filament contained in the glass yarn (glass filament) is classified as single glass filament. Among them, the “slip-off” of the filament not only includes slip-detachment in units of 1 single-glass filament and slip-detachment in units of several single-glass filaments, but also includes those that produce breaks in the filament. The number of slipped filaments may be determined using the method described in the Examples.

[0050] Preferably, the glass yarn is a glass yarn made of 40 to 240 single glass filaments with an average diameter of 3.5 to 5.5 mm, or a glass yarn with 30 to 120 single glass filaments. By using glass yarn with an average diameter and number of filaments within the above range, it is easy to manufacture glass cloth with thicknesses equivalent to the previous E glass cloth of 1000, 1017, 1015, 1012, 1027, 1024, 1020, 1030, 1037, 1035, 106, 1067, and 1078 (IPC specification (IPC-4412B): Style 1000, 1017, 1015, 1012, 1027, 1024, 1020, 1030, 1037, 1035, 106, 1067, and 1078).

[0051] (Elastic modulus of glass yarn) The elastic modulus of glass yarn is preferably 50-70 GPa, more preferably 50-63 GPa, and even more preferably 53-63 GPa. By making the elastic modulus above 50 GPa, the rigidity of the glass yarn is improved, and it is less prone to fuzzing during the manufacturing process. Furthermore, by making the elastic modulus below 70 GPa, the brittleness resistance of the glass yarn is improved, and it is less prone to fuzzing during the manufacturing process. Moreover, by making the elastic modulus within the above range, the following tendency is observed: the glass yarn has moderate flexibility, and it is less prone to filament breakage when subjected to mechanical loads, thereby reducing the likelihood of fuzzing and textile defects.

[0052] (Composition of glass yarn) Examples of constituent elements of glass yarn include silicon (Si), boron (B), aluminum (Al), calcium (Ca), magnesium (Mg), phosphorus (P), sodium (Na), potassium (K), titanium (Ti), zinc (Zn), iron (Fe), and fluorine (F).

[0053] The Si content of the glass yarn, converted to SiO2, is preferably 40-60% by mass, more preferably 45-55% by mass, even more preferably 47-53% by mass, and even more preferably 48-52% by mass.

[0054] Si is a component that forms the skeletal structure of glass fiber. By having a Si content of 40% by mass or more, the strength of the glass fiber is easily improved. This tends to further suppress breakage of the glass fiber in subsequent steps, such as the manufacturing process of the glass cloth and the manufacturing of the prepreg using the glass cloth. Furthermore, by having a Si content of 40% by mass or more, the dielectric constant of the glass fiber tends to decrease further. On the other hand, by having a Si content of 60% by mass or less, the viscosity during melting is further reduced during the filament manufacturing process, thereby enabling the acquisition of glass fibers with a more homogeneous glass composition. Therefore, areas prone to localized devitrification or areas where air bubbles are difficult to detach are less likely to occur in the obtained filament, thus reducing the likelihood of locally weak areas in the filament. Consequently, glass cloth containing glass fiber obtained using this filament is less prone to breakage. The Si content can be adjusted according to the amount of raw materials used in filament manufacturing.

[0055] The B content of the glass yarn, converted to B2O3, is preferably 15-40% by mass, more preferably 17-30% by mass, or 20-40% by mass, further preferably 18-28% by mass, further preferably 19-26% by mass, further preferably 20-25% by mass, and most preferably 20.5-24% by mass.

[0056] By increasing the B content to 15% by mass or more, there is a tendency for the dielectric constant to decrease further. Furthermore, by increasing the B content to 15% by mass or more, the following tendencies occur: due to the improved brittleness resistance of the glass cloth and the imparting of appropriate softness and flexibility, fuzz is less likely to form when the glass yarn comes into contact with weaving components such as yarn guides and reeds. On the other hand, to maintain the strength of the glass yarn, the B content is preferably 40% by mass or less. Also, by increasing the B content to 40% by mass or less, moisture absorption resistance is improved. The B content can be adjusted according to the amount of raw material used in filament production. Moreover, in cases where conditions, usage amounts, or content may change during filament production, this can be predicted in advance, and the amount of raw material added can be adjusted accordingly.

[0057] The Al content of the glass yarn, converted to alumina (Al2O3), is preferably 11-18% by mass, more preferably 11-16% by mass, and even more preferably 12-16% by mass. By keeping the Al content within the above range, there is a tendency to further improve the electrical properties and strength. The Al content can be adjusted according to the amount of raw materials used in the production of filaments.

[0058] The Ca content of the glass yarn, converted to calcium oxide (CaO), is preferably 5-10% by mass, more preferably 5-9% by mass, and even more preferably 5-8.5% by mass. By making the Ca content 5% by mass or more, there is a tendency to further reduce the viscosity during melting in the filament manufacturing process, thereby obtaining glass fibers with a more homogeneous glass composition. Furthermore, by making the Ca content 10% by mass or less, there is a tendency to further increase the dielectric constant. The Ca content can be adjusted according to the amount of raw materials used in filament production.

[0059] Glass yarn exhibits various superior properties by containing specified amounts of Mg, P, Na, K, Ti, Zn, Fe, and F. The contents of these elements can be adjusted according to the amount of raw materials used in the production of the filament.

[0060] The above-mentioned contents can be determined by ICP (Inductively Coupled Plasma) emission spectroscopy. Specifically, the Si and B contents can be obtained by dissolving the weighed glass cloth sample in sodium carbonate, then dissolving and adjusting the volume with dilute nitric acid, and finally measuring the obtained sample using ICP emission spectroscopy. The Fe content can be obtained by dissolving the weighed glass cloth sample using an alkaline dissolution method, then adjusting the volume, and finally measuring the obtained sample using ICP emission spectroscopy. Furthermore, the Al, Ca, and Mg contents can be obtained by heating and decomposing the weighed glass cloth sample with sulfuric acid, nitric acid, and hydrogen fluoride, then dissolving and adjusting the volume with dilute nitric acid, and finally measuring the obtained sample using ICP emission spectroscopy. Moreover, the PS3520VDD II manufactured by Hitachi High-Tech Science Corporation can be used as the ICP emission spectroscopy instrument.

[0061] (Dielectric constant of glass cloth) The dielectric constant of the glass cloth at a frequency of 10 GHz is preferably 5.0 or less, more preferably 4.9 or less, further preferably 4.8 or less, and especially preferably 4.6 or less. The dielectric constant of the glass cloth can be measured, for example, by cavity resonance. In this specification, unless otherwise specified, the dielectric constant of the glass cloth refers to the dielectric constant at a frequency of 10 GHz.

[0062] (Plant interval length of glass yarn and splint interval length difference index) The preferably 1.8~10.0 cm, preferably 1.9~9.9 cm, further preferably 1.95~4.0, and optimal 2.0~3.5. The minimum value of the spacing length of the addition is preferably 1.8 cm, preferably 1.9 cm, and further preferably 1.95 cm and optimally 2.0 cm. The maximum value of the spacing length of the addition is preferably 10.0 cm, preferably 9.9 cm, and further preferably 4.0 cm and optimally 3.5.

[0063] Also, the value obtained by the difference between the maximum value of the length of the splint interval and the minimum value of the length of the splint interval divided by the average of the splint interval length (the spun interval length difference index) is preferably less than 0.7, preferably less than 0.6, further preferably less than 0.5, optimally less than 0.4, and more than 0 is preferable. If the length of the adder spacing of the glass yarn, and / or the index of the length of the adder spacing is within the above numerical range, there is a tendency as follows: In the case of the glass yarn being wound around the cylinder tube, the above-mentioned number of slip-off filaments assessed at the outer part of the cylinder tube easily becomes less than 3, and / or the number of slip-off filaments decreases across the entire length of the cylinder tube. As a reason for the reduction in the number of slipped filaments, it is not desirable to be constrained by theory, but the following 3 are considered: (i) if the length of the splint spacing is longer than the lower limit value, the torsional shear stress can be suppressed to a smaller value, so filament slippage is less likely to occur; (iii) If the length difference index of the splint spacing is less than the upper limit value, the change in torsion angle can be suppressed to a smaller extent in the length direction of the glass yarn, and thus filament slippage is not prone to occur. Furthermore, the standard deviation of the addition number of the glass yarn is preferably 0.05 to 0.20, and preferably 0.09 to 0.18.

[0064] [Method of fabrication of glass cloth] A third embodiment in the present invention is a method of manufacturing glass cloth.

[0065] This embodiment is a method of manufacturing glass cloth comprising the step of using a glass yarn comprising a plurality of root filaments for warp and weft yarns to perform weaving. The glass yarns used were 1–13 as described above, (i) 1–13 dexes, (ii) 0.50–0.80 N / tex at breaking strength, and (iii) less than 3 slip filaments (number of filaments that occurred more than 2 times the average value of the yarn width at 180 m determination).

[0066] The manufacturing method can be specifically exemplified as follows: the method includes a glass yarn adjustment step, which adjusts the glass yarn so that the number of slipped filaments is below a specific number; a weaving step, which weaves the adjusted glass yarn to obtain glass cloth; and a fiber opening step, which opens the glass yarn of the glass cloth. The manufacturing method of the glass cloth may, as needed, include a desizing step to remove the sizing agent adhering to the glass yarn of the glass cloth, and a surface treatment step using a silane coupling agent. The steps in the manufacturing method of the glass cloth will be described in more detail below.

[0067] (Glass yarn adjustment step) The glass yarn adjustment step is a step of adjusting the glass yarn so that the number of slipped filaments is three or less. More specifically, in the glass yarn adjustment step, if the number of slipped filaments is within the above range, the glass yarn is used in subsequent weaving steps; if it is outside the range, the glass yarn is prohibited from being used.

[0068] The method for determining the number of slipped filaments can be exemplified as follows: while conveying the glass yarn, a displacement meter using light projection methods such as laser light or LED light is used to observe the yarn width and slipped filaments; while conveying the glass yarn, the shape of the glass yarn is observed using an image, and the yarn width and slipped filaments are observed at the same time.

[0069] (Weaving Step) The weaving step is the process of weaving glass yarn to obtain glass cloth. Examples of possible weaving structures for glass cloth include plain weave, square plain weave, satin weave, and twill weave. Plain weave is preferred.

[0070] In one example of the weaving step in the manufacturing method of this embodiment, a jet loom can be used to open the warp yarns that are pulled in parallel at the top and bottom, and the yarn supplied from the weft yarn accumulation device is sent out as weft yarn and passes through the opening by the jet stream of the nozzle, thereby performing weaving.

[0071] In this weaving step, during the process of the glass yarn, which will become the weft yarn, being wound out of the bobbin and ejected through the storage device, the glass yarn moves in a direction different from the direction of travel, accompanied by expansion and other movements, and is conveyed along with interference with weaving components such as the yarn guide; or because the weft yarn is repeatedly ejected and stopped in units of the length of one weft yarn, it is conveyed along with tension changes and interference with weaving components such as the yarn guide; therefore, the weft yarn with a large number of slipped filaments is difficult to minimize the damage caused by the above interference, and thus fuzz or textile defects will be generated in the obtained glass cloth.

[0072] In contrast, in this embodiment, by using glass yarn with a slippage filament count within a specific range, the generation of fuzz or textile defects is suppressed when the weft yarn is woven in, thereby improving the in-plane uniformity and batch-to-batch uniformity of the glass cloth. Furthermore, the weaving method is not limited to an air-jet loom, but can also be a water-jet loom or a shuttle loom.

[0073] The weave density of the warp and weft yarns constituting the glass cloth is preferably 30 to 120 yarns / 25 mm, more preferably 40 to 110 yarns / 25 mm, and even more preferably 45 to 105 yarns / 25 mm. The weave density of the warp yarns can be controlled by adjusting the spacing of the parallel-stretched warp yarns, and the weft yarn weave density can be controlled by the number of times the weft yarns are sprayed per unit time from the nozzle and the flow speed of the warp yarns.

[0074] (Fiber Opening Step) The fiber opening step is the step of opening the glass yarn of the glass cloth. Examples of fiber opening methods include using water spray (high-pressure water fiber opening), vibrating washer, ultrasonic water, rollers, etc.

[0075] The thickness of the glass cloth finally obtained after the fiber opening step is preferably 5 to 60 μm, more preferably 7 to 55 μm, and even more preferably 9 to 50 μm or 10 to 50 μm. By keeping the thickness of the glass cloth within the above range, it is possible to obtain a thinner glass cloth with relatively high strength. The weight (weight per unit area) of the glass cloth finally obtained after the fiber opening step is preferably 5 to 55 g / m2, more preferably 6 to 50 g / m2, and even more preferably 7 to 48 g / m2.

[0076] (Desizing Step) The desizing step is the step of removing the sizing agent adhering to the glass cloth. As a desizing method, for example, the method of removing the sizing agent by heating can be cited.

[0077] (Surface Treatment Step) The surface treatment step is a step of treating the surface of the glass cloth using a silane coupling agent. Furthermore, examples of surface treatment methods include contacting the surface treatment agent containing the silane coupling agent with the glass cloth and then drying it. Moreover, examples of contact between the surface treatment agent and the glass cloth include: immersing the glass cloth in the surface treatment agent; and applying the surface treatment agent to the glass cloth using a roller coater, a die coater, or a gravure coater. The drying method for the surface treatment agent is not particularly limited; for example, hot air drying and drying using electromagnetic waves can be used.

[0078] [Prepreg] The prepreg comprises a glass cloth obtained as described above and a matrix resin composition impregnated in the glass cloth. The prepreg having the above-described glass cloth exhibits less quality variation and results in a higher yield of the final product.

[0079] The prepreg can be manufactured according to conventional methods. For example, it can be manufactured by impregnating a varnish made by diluting a matrix resin such as epoxy resin with an organic solvent in glass cloth, and then using a drying oven to evaporate the organic solvent and harden the thermosetting resin to stage B (semi-hardened state).

[0080] In addition to the epoxy resin described above, examples of the matrix resin composition include: thermosetting resins such as bismaleimide resin, cyanate ester resin, unsaturated polyester resin, polyimide resin, BT resin (Bismaleimide Triazine), and functionalized polyphenylene ether resin; thermoplastic resins such as polyphenylene ether resin, polyether amide resin, liquid crystal polymer (LCP) of fully aromatic polyester, polybutadiene, and fluoropolymers; and mixed resins thereof. From the viewpoint of improving dielectric properties, heat resistance, solvent resistance, and compressive molding properties, a resin obtained by modifying a thermoplastic resin with a thermosetting resin can also be used as the matrix resin composition.

[0081] Furthermore, the matrix resin composition may also contain the following inorganic fillers in the resin: silicon dioxide and aluminum hydroxide; flame retardants such as bromine-based, phosphorus-based, and metal hydroxides; other silane coupling agents; heat stabilizers; antistatic agents; ultraviolet absorbers; pigments; colorants; lubricants, etc.

[0082] [Printed Wiring Board] The printed wiring board preferably has the above-described prepreg. Printed wiring boards with the above-described prepreg have less quality variation and a higher yield of the final product. Furthermore, printed wiring boards with the above-described prepreg have excellent dielectric properties and excellent moisture resistance, thus exhibiting less variation in dielectric constant under the influence of the operating environment, especially in high humidity environments. [Example]

[0083] Hereinafter, the present invention will be described in more detail using examples and comparative examples.

[0084] [Physical properties of glass yarn and glass cloth] Specifically, the physical properties of glass yarn and glass cloth, namely the thickness of glass cloth, the average diameter of the filaments constituting the glass yarn, the strength of glass yarn, the breaking strength (tensile strength) of glass yarn, and the weaving density (weaving density) of warp and weft yarns, are measured in accordance with JIS R3420.

[0085] [Add pin interval length, add pin interval length difference index] Using an inspector (manufactured by TECHNOS Company), determine the adder number of a glass yarn of 50 cm. The length data of each splint interval for 30 points were calculated by repeatedly determining the number of splints per 50 cm for 30 points using the method. The length data of each 1 adder interval of the 30 points obtained were averaged to obtain the length of the adder interval.

[0086] Also, the ratio of the difference between the maximum and minimum value of the adder interval length with respect to the average of the adder interval length is obtained using the average, maximum, and minimum values ​​of the obtained 30 points of the adder interval length. Difference index of length of addition interval = {(maximum value of addition interval length - minimum value of addition interval length) / average value of addition interval length} × 100... (1)

[0087] [Standard deviation of adder number] Using a pin detector (manufactured by TECHNOS Company), the adder number of 50 cm of glass yarn was determined and converted to adder number per 25 mm. The method was used to repeatedly determine the summation per 25 mm at 30 points, and the standard deviation of the summation data of the 30 points obtained was obtained.

[0088] [Elasticity coefficient] The elastic coefficient of the glass yarn is determined by using the glass block obtained by melting and cooling the glass yarn as a test piece and using the pulse-echo superposition method.

[0089] [Number of slipped filaments] The glass yarn was carried at a speed of 1 m / min, while a sizer (HIGH ACCURACY CMOS MICROMETER LS-9006MR / Manufactured by Keenz Corporation) in the form of an LED camera was used to observe the shape projected by the glass yarn using a monitor on one side and the yarn width was continuously determined on the other. The yarn width of the glass yarn at 180 m was determined. Also, the counting of the observed cases where the filament slipped more than 2 times the width of the yarn width at the center of the yarn width was counted, and their total was set as the “number of slipped filaments”, that is, “the number of filaments in which slippage more than 2 times the average value of the yarn width occurred at 180 m determination”.

[0090] Here, the yarn width measurement performed by the size measuring device using an LED camera is performed under the condition that 1934 measurement values ​​can be obtained per 1 m. In the event of an error such as the LED not being focused (displaying a value of -9999), the measurement value is deleted, thereby calculating the average value of the yarn width and / or the number of slipped filaments.

[0091] Furthermore, the tension acting on the glass yarn during transport is the tension measured by a tension meter (Conrol instruments ETPB-100-C0585 manufactured by SCHMIDT), which is 0.12 to 0.18 N.

[0092] [Bob tube appearance inspection (hair inspection)] Visually inspect the appearance of the bobbin wrapped with glass yarn and count the number of hairs detected. Perform this inspection 50 times and calculate the average number of hairs.

[0093] [Fiber inspection of glass yarn under load and evaluation] Using a fiber inspection device manufactured by NIHON KAGAKU ENG, glass yarn was fed at a speed of 1 m / min while passing through a mandrel with a reed tooth spacing of 0.35 mm that made 450 reciprocations per minute to smooth it out. The number of fibers generated per 180 m was counted using a sensor. Alternatively, the reciprocating speed of the mandrel was set to 100 reciprocations per minute, and the number of fibers generated per 180 m was counted using the same method.

[0094] [Evaluation: Hairiness Quality of Glass Cloth] The influence of glass yarn quality (e.g., slippage filament count) on the hairiness quality of glass cloth was studied. As a standard condition for glass cloth manufacturing, the loom speed was set to 450 rpm, and fiber opening treatment was performed by high-pressure water spray. Furthermore, the loom speed was increased (550, 600 rpm) to improve productivity, and the intensity of high-pressure water spray was increased to improve properties.

[0095] The fuzz quality of the glass cloth obtained in the Examples, Comparative Examples, and Reference Examples was evaluated using visual inspection. A glass cloth inspection machine was used, and the glass cloth was transported at a speed of 10 m / min while the fuzz quality of the glass cloth was evaluated visually. In the previous visual inspection, the fuzz and textile defects were observed on the portion of the glass cloth where light was reflected when halogen lamps were shone at a right angle. However, to observe the broken filaments less than 1 mm in length with good sensitivity, a white LED light was shone from the end side of the glass cloth in a direction parallel to the surface of the glass cloth for visual inspection. Fuzz was dispersed throughout the entire surface of the glass cloth, so the state of fuzz formation observed by shining light throughout the entire surface of the glass cloth was defined as a surface-wide fuzz defect. The fuzz formation at the surface-wide fuzz formation area was observed using an optical microscope, and it was found that many fuzzes caused by the breakage of filaments approximately 200 μm to 1000 μm were produced.

[0096] Taking a measurement length of 500 m as the object, if there is a situation where there is fuzz on the entire surface within a 1 m range along the length of the glass cloth, the defect number is counted as 1, and the defect rate is calculated according to the following formula: Defect rate (%) = (Total number of defects / 500) × 100

[0097] [Evaluation: Impregnation Evaluation of Glass Cloth] Bisphenol A type epoxy resin was dissolved in benzyl alcohol at 23±2°C to prepare a varnish for impregnation evaluation with a viscosity of 230±5 mPa・s. Subsequently, glass cloth test pieces were immersed in the varnish for impregnation evaluation, and transverse light was irradiated while the impregnation of the varnish into the glass cloth was observed using an optical microscope. Furthermore, the number of voids (unimpregnated areas) was counted after immersing the glass cloth test pieces in the varnish for 5 minutes. At this time, the field of view of the glass cloth observed using the optical microscope was set to approximately 6.5 mm in the warp direction and approximately 9 mm in the weft direction.

[0098] [Examples and Comparative Examples; Glass Yarn] [Experimental Example 1] The outermost layer of glass yarn A-N (low dielectric glass yarn, density 2.3 g / cm3, elastic modulus 61 GPa), O-Q (low dielectric glass yarn, density 2.3 g / cm3, elastic modulus 56 GPa), and R (E glass yarn, density 2.6 g / cm3, elastic modulus 74 GPa) that were wound on a bobbin were unwound. The number of slipped filaments was measured at a point 5 m away from the end in the length direction as the starting point T0.

[0099] [Experimental Example 2] Subsequently, the number of slipped filaments was measured at the point where 500 m of glass yarn was further unwound from the bobbin, that is, at the point 500 m away from the starting point T0 in the length direction.

[0100] [Experimental Example 3] In accordance with Experimental Examples 1 and 2 above, the glass yarn was further unwound from the bobbin, with the following starting points: T1,000, T2,000, T5,000, T7,000, T9,000, T10,000, T20,000, T10,000, and T20,000. The points 10,000 m and 20,000 m from the starting point T0 in the length direction were designated as the starting point T1,000; T2, T3, T4, T5,000, T5, T6, T7,000, T8, T9, T9, T9, T9, T9, T10, T10, T10, T10, T10, T10, T10, T110, T120, T13, T14, T15, T16, T17, T18, T19, T10, T10, T11, T120, T13, T14, T15, T16, T17, T18, T19 ...20, T13, T14, T15, T16, T17, T18, T19, T19, T120, T13, T14, T19, T10, T11, T120, T13, T14, T15, T16, T17, T18, T19, T19, T19, T10, T120, T The starting point T30,000 is defined as the location 30,000 m away from the starting point T0 along the length direction; the starting point T40,000 is defined as the location 40,000 m away from the starting point T0 along the length direction; the starting point T50,000 is defined as the location 50,000 m away from the starting point T0 along the length direction; the starting point T60,000 is defined as the location 60,000 m away from the starting point T0 along the length direction; the starting point T70,000 is defined as the location 70,000 m away from the starting point T0 along the length direction; the starting point T80,000 is defined as the location 80,000 m away from the starting point T0 along the length direction; the starting point T100,000 is defined as the location 100,000 m away from the starting point T0 along the length direction; the starting point T20,000 is defined as the location 120,000 m away from the starting point T0 along the length direction. The starting point T120,000 was determined at point m; the number of slipped filaments was measured. The results are shown in Table 1.

[0101] [Table 1-1] Table 1-1 Glass yarn A Glass yarn B Glass yarn C Glass yarn D Glass yarn E Glass yarn F Glass yarn G Glass yarn H Glass yarn I Example A Example B Example C Compare Example D Compare Example E Compare Example F Example G Example H Compare Example I Glass yarn characteristics Yarn length (m) Approximately 145,000 Approximately 145,000 Approximately 145,000 Approximately 145,000 Approximately 145,000 Approximately 145,000 About 84,000 About 84,000 About 84,000 taxi 4.9 4.9 4.9 4.9 4.9 4.9 2.9 2.9 2.9 Number of filament roots 100 100 100 100 100 100 100 100 100 Breaking Strength (N / TEX) 0.61 0.67 0.64 0.69 0.63 0.65 0.74 0.69 0.72 Add the minimum value of the spacing length (cm) 2.27 2.17 2.00 1.76 1.61 1.85 2.17 1.97 1.75 Add the maximum value of the spacing length (cm) 3.11 3.11 3.14 3.75 3.85 4.56 2.90 3.32 3.91 Add the average of the spacing length (cm) 2.52 2.52 2.53 2.52 2.50 2.51 2.49 2.47 2.50 Add the interval length difference index 0.33 0.37 0.45 0.79 0.89 1.08 0.29 0.55 0.86 Add the standard deviation of the fuck 0.09 0.09 0.15 0.09 0.17 0.19 0.13 0.12 0.13 Glass Yarn Quality Number of slipped filaments (number of filaments with slippage occurring more than 2 times the average value of the yarn width at 180 m determination) (the) 180 m in the length direction from the starting point T0 0 1 3 4 6 10 1 3 4 From the starting point T5 00180 m along its length 0 0 2 4 7 9 0 2 5 Starting from T1 , 000 180 m along its length 0 0 2 3 6 11 0 2 5 From the starting point T 2,000 180 m along its length 0 0 3 3 7 10 1 2 4 From the starting point T 5,000 180 m along its length 0 1 3 4 7 11 0 2 4 From the starting point T 7,000 180 m along its length 0 0 3 4 7 9 0 3 4 From the starting point T 9,000 180 m along its length 0 1 2 5 5 12 1 2 5 From the starting point T 10, 000 180 m along its length 0 0 3 4 6 10 1 2 5 From the starting point T 20 , 000 180 m along its length 0 1 2 5 6 8 1 2 4 From the starting point T 30,000 180 m along its length 0 0 2 4 6 10 0 2 5 From the starting point T 40 , 000 180 m along its length 0 2 3 4 7 12 1 3 5 From the starting point T 50,000 180 m along its length 0 1 2 5 8 11 0 3 6 From the starting point T 60,000 180 m along its length 1 1 3 4 7 10 0 3 6 From the starting point T 70 , 000 180 m along its length 0 1 3 6 8 13 1 2 6 From the starting point T 80,000 180 m along its length 0 2 3 5 8 13 0 3 7 From the starting point T 100,000 180 m along its length 0 2 2 5 7 15 - - - From the starting point T 120,000 180 m along its length 0 2 3 5 8 13 - - -

[0102] [Table 1-2] Table 1-2 Glass yarn J Glass yarn K Glass yarn L Glass yarn M Glass yarn N Glass yarn O Glass yarn P Glass yarn Q Glass yarn R ExampleJ Example K Compare Example L Compare Example M Compare ExampleN Example O Example P Compare Example Q Comparative Example R Glass yarn characteristics Yarn length (m) About 71,000 About 71,000 About 71,000 About 96,000 About 71,000 About 55,000 About 55,000 About 55,000 About 150,000 taxi 9.8 9.8 9.8 14.6 19.4 4.8 4.8 4.8 5.5 Number of filament roots 200 200 200 200 200 100 100 100 100 Breaking Strength (N / TEX) 0.76 0.74 0.75 0.72 0.67 0.55 0.53 0.56 0.88 Add the minimum value of the spacing length (cm) 2.17 1.92 1.47 1.56 1.72 2.00 1.85 1.72 1.76 Add the maximum value of the spacing length (cm) 3.13 3.33 3.86 4.13 3.79 3.13 3.56 3.85 3.69 Add the average of the spacing length (cm) 2.52 2.50 2.51 2.53 2.50 2.50 2.48 2.50 2.50 Add the interval length difference index 0.38 0.56 0.95 1.01 0.83 0.45 0.69 0.85 0.77 Add the standard deviation of the fuck 0.14 0.14 0.15 0.15 0.16 0.17 0.18 0.18 0.13 Glass Yarn Quality Number of slipped filaments (number of filaments with slippage occurring more than 2 times the average value of the yarn width at 180 m determination) (the) 180 m in the length direction from the starting point T0 1 3 4 5 5 1 3 4 5 From the starting point T 500180 m along its length 1 2 5 5 6 0 2 4 5 From the starting point T 1,000 180 m along its length 0 3 4 6 6 1 2 5 6 From the starting point T 2,000 180 m along its length 1 2 5 5 6 0 3 4 5 From the starting point T 5,000 180 m along its length 0 2 5 6 5 1 2 6 4 From the starting point T 7,000 180 m along its length 0 2 5 5 6 1 2 4 5 From the starting point T 9,000 180 m along its length 0 3 4 5 6 1 2 4 5 Starting from T10,000 180 m along its length 0 3 5 7 5 0 2 5 5 From the starting point T 20,000 180 m along its length 0 3 5 5 5 1 2 5 5 From the starting point T 30,000 180 m along its length 0 2 6 6 7 1 3 6 5 From the starting point T 40,000 180 m along its length 1 2 5 6 8 1 3 5 4 From the starting point T 50,000 180 m along its length 1 2 6 7 7 - - - 6 From the starting point T 60,000 180 m along its length 0 3 6 7 7 - - - 6 From the starting point T70,000 180 m in the direction of starting length 1 3 7 8                    ——                    ——                    ——                    —— 6 From the starting point T 80,000 180 m in the direction of starting length                    ——                    ——                    —— 9                    ——                    ——                    ——                    —— 6 From the starting point T 10 0,000 180 m in the direction of starting length                    ——                    ——                    ——                    ——                    ——                    ——                    ——                    —— 5 From the starting point T 120,000 180 m in the direction of starting length                    ——                    ——                    ——                    ——                    ——                    ——                    ——                    —— 6

[0103] The number of slipped filaments evaluated in the outer part of the cylinder tube is less than 3. Glass yarns A~C, G, H, J, K, O, and P of embodiments with pins are applied uniformly and smoothly with a smaller and uniformly smooth length difference index. Moreover, the number of slipped filaments was also less than three when the assay was performed from any one of the starting point T0, the starting point T500, the starting point T1,000, the starting point T2,000, the starting point T5,000, the starting point T7,000, and the starting point T9,000. By this it can be confirmed that the number of slipped filaments was less than three in each of the assay ranges of the above five sites when selecting a determination range of 180 m in the length direction at five sites with a length of more than 10,000 m as the object.

[0104] It can be confirmed that even with a glass yarn having a length of more than 50,000 m as the object, the number of slipped filaments is less than 3 in each of the assay ranges of the above 7 sites when selecting a determination range of 180 m in the length direction at seven sites that are different from each other according to the same subject as described above.

[0105] It can be confirmed that, even with a glass yarn having a length of more than 100,000 m as the object, the number of slipped filaments in each of the assay ranges of the above 10 sites is less than 3 when selecting a determination range of 180 m in the length direction at 10 sites that are different from each other according to the same subject as described above.

[0106] On the other hand, the number of slipped filaments of glass yarns D~F, I, L~N, Q, and R in the specified assay range is more than 4.

[0107] [Example 1] The low dielectric glass yarn described in the table below (Dex 4.9, number of filament roots GPa, glass composition: 51.2 mass% for SiO2, 14.3 mass% for Al2O3, 8.1 mass% for CaO, 0.3 mass% for MgO, 23.3 mass% for B2O3, and 0.1 mass% for P2O3) for warp yarn-turned gas looms and 4 Under conditions of rpm (weaving-in speed of 450 strands / min), glass fabric blanks with a warp braid density of 65 strands / 25 mm and a weft braid density of 67 strands / 25 mm were obtained. In the table, as indicated by the item “Number of slipped filaments measured from starting point T0”, in embodiment 1, a glass yarn with a filament number of 0 that occurs with slip more than 2 times the average value of the yarn width at 180 m determined from the above starting point T0 is used.

[0108] Following this, a glass cloth with a thickness of 29 μm was prepared by using a heated glass cloth blank for degluing treatment and using a spray adjusting the water pressure to 5.0 ± 0.1 kg / cm2 to implement high-pressure water opening.

[0109] [Example 2] In addition to using the low dielectric glass yarn described in the table below (Dex 4.9, number of filament roots 100, elasticity coefficient 61) GPa, Glass Composition: 51.2 by mass % for SiO2, 14.3 % by mass for Al

[0110] [Example 3] Except for using the low dielectric glass yarn (Texas 4.9, 100 filaments, elastic modulus 61 GPa, glass composition: 51.2% by mass of SiO2, 14.3% by mass of Al2O3, 8.1% by mass of CaO, 0.3% by mass of MgO, 23.3% by mass of B2O3, and 0.1% by mass of P2O3) as described in the table below, a glass cloth with a thickness of 29 μm was made in the same manner as in Example 1.

[0111] [Example 4] Except for using the low dielectric glass yarn (Texas 4.9, 100 filaments, elastic modulus 61 GPa, glass composition: 51.2% by mass of SiO2, 14.3% by mass of Al2O3, 8.1% by mass of CaO, 0.3% by mass of MgO, 23.3% by mass of B2O3, and 0.1% by mass of P2O3) as described in the table below, a glass cloth with a thickness of 29 μm was made in the same manner as in Example 1.

[0112] [Comparative Example 1] Except for using the low dielectric glass yarn (Texas 4.9, 100 filaments, elastic modulus 61 GPa, glass composition: 51.2% by mass of SiO2, 14.3% by mass of Al2O3, 8.1% by mass of CaO, 0.3% by mass of MgO, 23.3% by mass of B2O3, and 0.1% by mass of P2O3) listed in the table below, a glass cloth with a thickness of 29 μm was prepared in the same manner as in Example 1.

[0113] [Comparative Example 2] Except for using the low dielectric glass yarn (Texas 4.9, 100 filaments, elastic modulus 61 GPa, glass composition: 51.2% by mass of SiO2, 14.3% by mass of Al2O3, 8.1% by mass of CaO, 0.3% by mass of MgO, 23.3% by mass of B2O3, and 0.1% by mass of P2O3) listed in the table below, a glass cloth with a thickness of 29 μm was prepared in the same manner as in Example 1.

[0114] [Comparative Example 3] Except for using the low dielectric glass yarn (Texas 4.9, 100 filaments, elastic modulus 61 GPa, glass composition: 51.2% by mass of SiO2, 14.3% by mass of Al2O3, 8.1% by mass of CaO, 0.3% by mass of MgO, 23.3% by mass of B2O3, and 0.1% by mass of P2O3) listed in the table below, a glass cloth with a thickness of 29 μm was prepared in the same manner as in Example 1.

[0115] [Example 5] Except that the loom speed of the air-jet loom was set to 550 rpm, a glass cloth with a thickness of 29 μm was produced in the same manner as in Example 1.

[0116] [Example 6] Except that the loom speed of the air-jet loom was set to 550 rpm, a glass cloth with a thickness of 29 μm was produced in the same manner as in Example 3.

[0117] [Comparative Example 4] Except that the loom speed of the air-jet loom was set to 550 rpm, a glass cloth with a thickness of 29 μm was produced in the same manner as in Comparative Example 1.

[0118] [Example 7] Except that the loom speed of the air-jet loom was set to 600 rpm, a glass cloth with a thickness of 29 μm was produced in the same manner as in Example 1.

[0119] [Example 8] Except that the loom speed of the air-jet loom was set to 600 rpm, a glass cloth with a thickness of 29 μm was produced in the same manner as in Example 3.

[0120] [Comparative Example 5] Except that the loom speed of the air-jet loom was set to 600 rpm, a glass cloth with a thickness of 29 μm was produced in the same manner as in Comparative Example 1.

[0121] [Example 9] Except for increasing the fiber opening strength by increasing the water pressure of the high-pressure water spray in the fiber opening process to 12.0±0.1 kg / cm2, a glass cloth with a thickness of 29 μm was made in the same manner as in Example 1.

[0122] [Example 10] Except for increasing the fiber opening strength by increasing the water pressure of the high-pressure water spray in the fiber opening process to 12.0±0.1 kg / cm2, a glass cloth with a thickness of 29 μm was made in the same manner as in Example 3.

[0123] [Comparative Example 6] Except for increasing the fiber opening strength by increasing the water pressure of the high-pressure water spray in the fiber opening process to 12.0±0.1 kg / cm2, a glass cloth with a thickness of 29 μm was made in the same manner as in Comparative Example 1.

[0124] [Comparative Example 7] Except for increasing the fiber opening strength by increasing the water pressure of the high-pressure water spray in the fiber opening process to 12.0±0.1 kg / cm2, a glass cloth with a thickness of 29 μm was made in the same manner as in Comparative Example 2.

[0125] [Comparative Example 8] Except for increasing the fiber opening strength by increasing the water pressure of the high-pressure water spray in the fiber opening process to 12.0±0.1 kg / cm2, a glass cloth with a thickness of 29 μm was made in the same manner as in Comparative Example 3.

[0126] [Example 11] The low dielectric glass yarn (Texas 2.9, 100 filaments, elastic modulus 61 GPa, glass composition: 51.2% by mass of SiO2, 14.3% by mass of Al2O3, 8.1% by mass of CaO, 0.3% by mass of MgO, 23.3% by mass of B2O3, and 0.1% by mass of P2O3) listed in the table below was used for warp and weft yarns. Under the condition of a loom speed of 450 rpm (weft yarn weaving speed of 450 yarns / minute) on an air-jet loom, a glass cloth fabric with a warp yarn weaving density of 74 yarns / 25 mm and a weft yarn weaving density of 74 yarns / 25 mm was obtained.

[0127] Then, the glass cloth blank is de-spun by heating, and high-pressure water fiber opening is carried out by spraying with water pressure adjusted to 4.0±0.1kg / cm2. Then, the surface is treated with silane coupling agent to produce a glass cloth with a thickness of 21 μm.

[0128] [Example 12] Except for using the low dielectric glass yarn (Texas 2.9, 100 filaments, elastic modulus 61 GPa, glass composition: 51.2% by mass of SiO2, 14.3% by mass of Al2O3, 8.1% by mass of CaO, 0.3% by mass of MgO, 23.3% by mass of B2O3, and 0.1% by mass of P2O3) as described in the table below, a glass cloth with a thickness of 21 μm was made in the same manner as in Example 11.

[0129] [Comparative Example 9] Except for using the low dielectric glass yarn (Texas 2.9, 100 filaments, elastic modulus 61 GPa, glass composition: 51.2% by mass of SiO2, 14.3% by mass of Al2O3, 8.1% by mass of CaO, 0.3% by mass of MgO, 23.3% by mass of B2O3, and 0.1% by mass of P2O3) listed in the table below, a glass cloth with a thickness of 21 μm was prepared in the same manner as in Example 11.

[0130] [Example 13] Except for increasing the fiber opening strength by increasing the water pressure of the high-pressure water spray in the fiber opening process to 10.0±0.1 kg / cm2, a glass cloth with a thickness of 21 μm was made in the same manner as in Example 11.

[0131] [Comparative Example 10] Except for increasing the fiber opening strength by increasing the water pressure of the high-pressure water spray in the fiber opening process to 10.0±0.1 kg / cm2, a glass cloth with a thickness of 21 μm was produced in the same manner as in Comparative Example 9.

[0132] [Example 14] The low dielectric glass yarn (Texas 9.8, 200 filaments, elastic modulus 61 GPa, glass composition: 51.2% by mass of SiO2, 14.3% by mass of Al2O3, 8.1% by mass of CaO, 0.3% by mass of MgO, 23.3% by mass of B2O3, and 0.1% by mass of P2O3) listed in the table below was used for warp and weft yarns. Under the condition of a loom speed of 450 rpm (weft yarn weaving speed of 450 yarns / minute) on an air-jet loom, a glass cloth fabric with a warp yarn weaving density of 52.5 yarns / 25 mm and a weft yarn weaving density of 52.5 yarns / 25 mm was obtained.

[0133] Then, the glass cloth blank is de-spun by heating, and high-pressure water fiber opening is carried out by spraying with water pressure adjusted to 6.0±0.1 kg / cm. Then, the surface is treated with silane coupling agent to produce a glass cloth with a thickness of 46 μm.

[0134] [Example 15] Except for using the low dielectric glass yarn (Texas 9.8, 200 filaments, elastic modulus 61 GPa, glass composition: 51.2% by mass of SiO2, 14.3% by mass of Al2O3, 8.1% by mass of CaO, 0.3% by mass of MgO, 23.3% by mass of B2O3, and 0.1% by mass of P2O3) as described in the table below, a glass cloth with a thickness of 46 μm was made in the same manner as in Example 14.

[0135] [Comparative Example 11] Except for using the low dielectric glass yarn (Texas 9.8, 200 filaments, elastic modulus 61 GPa, glass composition: 51.2% by mass of SiO2, 14.3% by mass of Al2O3, 8.1% by mass of CaO, 0.3% by mass of MgO, 23.3% by mass of B2O3, and 0.1% by mass of P2O3) listed in the table below, a glass cloth with a thickness of 46 μm was prepared in the same manner as in Example 14.

[0136] [Example 16] Except for increasing the fiber opening strength by increasing the water pressure of the high-pressure water spray in the fiber opening process to 12.0±0.1 kg / cm2, a glass cloth with a thickness of 46 μm was produced in the same manner as in Example 14.

[0137] [Comparative Example 12] Except for increasing the fiber opening strength by increasing the water pressure of the high-pressure water spray in the fiber opening process to 12.0±0.1 kg / cm2, a glass cloth with a thickness of 46 μm was produced in the same manner as in Comparative Example 11.

[0138] [Example 17] The low dielectric glass yarn (Texas 4.8, 100 filaments, elastic modulus 56 GPa, glass composition: 49.8% by mass of SiO2, 16.8% by mass of Al2O3, 3.1% by mass of CaO, 0.1% by mass of MgO, 23.9% by mass of B2O3, and 4.0% by mass of P2O3) listed in the table below was used for warp and weft yarns. Under the condition of a loom speed of 450 rpm (weft yarn weaving speed of 450 yarns / minute) on an air-jet loom, a glass cloth fabric with a warp yarn weaving density of 65 / 25 mm and a weft yarn weaving density of 67 yarns / 25 mm was obtained.

[0139] Then, the glass cloth blank is de-spun by heating, and high-pressure water fiber opening is carried out by spraying with water pressure adjusted to 5.0±0.1 kg / cm2. Then, the surface is treated with silane coupling agent to produce a glass cloth with a thickness of 31 μm.

[0140] [Example 18] Except for using the low dielectric glass yarn (Texas 4.8, 100 filaments, elastic modulus 56 GPa, glass composition: 49.8% by mass of SiO2, 16.8% by mass of Al2O3, 3.1% by mass of CaO, 0.1% by mass of MgO, 23.9% by mass of B2O3, and 4.0% by mass of P2O3) as described in the table below, a glass cloth with a thickness of 31 μm was made in the same manner as in Example 17.

[0141] [Comparative Example 13] Except for using the low dielectric glass yarn (Texas 4.8, 100 filaments, elastic modulus 56 GPa, glass composition: 49.8% by mass of SiO2, 16.8% by mass of Al2O3, 3.1% by mass of CaO, 0.1% by mass of MgO, 23.9% by mass of B2O3, and 4.0% by mass of P2O3) as described in the table below, a glass cloth with a thickness of 31 μm was prepared in the same manner as in Example 15.

[0142] [Example 19] Except for increasing the fiber opening strength by increasing the water pressure of the high-pressure water spray in the fiber opening process to 12.0±0.1 kg / cm2, a glass cloth with a thickness of 31 μm was made in the same manner as in Example 17.

[0143] [Comparative Example 14] Except for increasing the fiber opening strength by increasing the water pressure of the high-pressure water spray in the fiber opening process to 12.0±0.1 kg / cm2, a glass cloth with a thickness of 31 μm was made in the same manner as in Comparative Example 13.

[0144] [Reference Example 1a] Low dielectric glass yarn (Texas 14.6, 200 filaments, elastic modulus 61 GPa, glass composition: 51.2% by mass of SiO2, 14.3% by mass of Al2O3, 8.1% by mass of CaO, 0.3% by mass of MgO, 23.3% by mass of B2O3, and 0.1% by mass of P2O3) with a slip filament count of 5 to 10 was used for warp and weft yarns. Glass cloth fabric with a warp yarn weaving density of 59 yarns / 25 mm and a weft yarn weaving density of 61 yarns / 25 mm was obtained under the condition of a loom speed of 450 rpm (weft yarn weaving speed of 450 yarns / min).

[0145] Then, the glass cloth blank is de-spun by heating, and high-pressure water fiber opening is carried out by spraying with water pressure adjusted to 7.0±0.1 kg / cm2. Then, the surface is treated with silane coupling agent to produce a glass cloth with a thickness of 73 μm.

[0146] [Reference Example 1b] Except for increasing the fiber opening strength by increasing the water pressure of the high-pressure water spray in the fiber opening process to 12.0±0.1 kg / cm2, a glass cloth with a thickness of 73 μm was produced in the same manner as in Reference Example 1a.

[0147] [Reference Example 2a] Low dielectric glass yarn (Texas 19.4, 200 filaments, elastic modulus 61 GPa, glass composition: 51.2% by mass of SiO2, 14.3% by mass of Al2O3, 8.1% by mass of CaO, 0.3% by mass of MgO, 23.3% by mass of B2O3, and 0.1% by mass of P2O3) with a slip filament count of 5 to 10 was used for warp and weft yarns. Under the condition of a loom speed of 450 rpm (weft yarn weaving speed of 450 yarns / minute) on an air-jet loom, a glass cloth fabric with a warp yarn weaving density of 60 yarns / 25 mm and a weft yarn weaving density of 57 yarns / 25 mm was obtained.

[0148] Then, the glass cloth blank is de-spun by heating, and high-pressure water fiber opening is carried out by spraying with water pressure adjusted to 7.0±0.1 kg / cm2. Then, the surface is treated with silane coupling agent to produce a glass cloth with a thickness of 89 μm.

[0149] [Reference Example 2b] Except for increasing the fiber opening strength by increasing the water pressure of the high-pressure water spray in the fiber opening process to 12.0±0.1 kg / cm2, a glass cloth with a thickness of 89 μm was produced in the same manner as in Reference Example 2a.

[0150] [Reference Example 3a] E-glass yarn (Texas 5.5, 100 filaments, elastic modulus 74 GPa, glass composition: 53.1% by mass of SiO2, 15.3% by mass of Al2O3, 21.0% by mass of CaO, 1.9% by mass of MgO, 8.0% by mass of B2O3, and <0.1% by mass of P2O3) with a slip count of 5 to 10 was used for warp and weft yarns. Under the condition of a loom speed of 450 rpm (weft yarn weaving speed of 450 yarns / minute) on an air-jet loom, a glass cloth fabric with a warp yarn weaving density of 65 yarns / 25 mm and a weft yarn weaving density of 67 yarns / 25 mm was obtained.

[0151] Then, the glass cloth blank is de-spun by heating, and high-pressure water fiber opening is carried out by spraying with water pressure adjusted to 5.0±0.1 kg / cm2. Then, the surface is treated with silane coupling agent to produce a glass cloth with a thickness of 29 μm.

[0152] [Reference Example 3b] Except for increasing the fiber opening strength by increasing the water pressure of the high-pressure water spray in the fiber opening process to 12.0±0.1 kg / cm2, a glass cloth with a thickness of 89 μm was produced in the same manner as in Reference Example 3a.

[0153] The evaluation results related to glass yarn and glass cloth in the above embodiments, comparative examples and reference examples are shown in the table below. Furthermore, in the table, the description of "±0.1 (kg / cm2)" is omitted from the item "Water pressure during high-pressure water fiber opening (kg / cm2)".

[0154] [Table 2-1] Table 2-1 Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Glass yarn The number of slipped filaments (pieces) measured from point T0. 0 1 3 0~3 4 5 6~10 Number of hairs (hairs) produced when a load is applied to glass yarn [100 cycles / minute] 1 4 4 4 4 8 13 Number of hairs (hairs) produced when a load is applied to glass yarn [450 reciprocating cycles / minute] 3 8 7 8 8 10 34 The average number of hairs detected during the visual inspection of the tube (number of hairs). 0.1 0.3 0.4 0.3 0.4 0.5 2.4 Manufacturing conditions Loom speed (rpm) 450 450 450 450 450 450 450 Water pressure during high-pressure fiber opening (kg / cm) 2 ) 5.0 5.0 5.0 5.0 5.0 5.0 5.0 Evaluation results Fiberglass cloth thickness (μm) 29 29 29 29 29 29 29 Defect rate (%) 0.0 0.3 1.9 1.1 3.6 6.0 12.3 Number of gaps (roots) 2.2 2.6 2.6 2.2 2.6 2.4 2.2

[0155] [Table 2-2] Table 2-2 Example 5 Example 6 Comparative Example 4 Example 7 Example 8 Comparative Example 5 Glass yarn The number of slipped filaments (pieces) measured from point T0. 0 3 4 0 3 4 Manufacturing conditions Loom speed (rpm) 550 550 550 600 600 600 Water pressure during high-pressure fiber opening (kg / cm) 2 ) 5.0 5.0 5.0 5.0 5.0 5.0 Evaluation results Fiberglass cloth thickness (μm) 29 29 29 29 29 29 Defect rate (%) 0 2.3 18.3 0.6 2.9 32.2

[0156] [Table 2-3] Table 2-3 Example 9 Example 10 Comparative Example 6 Comparative Example 7 Comparative Example 8 Glass yarn The number of slipped filaments (pieces) measured from point T0. 1 3 4 5 6~10 Manufacturing conditions Loom speed (rpm) 450 450 450 450 450 Water pressure during high-pressure fiber opening (kg / cm) 2 ) 12.0 12.0 12.0 12.0 12.0 Evaluation results Fiberglass cloth thickness (μm) 29 29 29 29 29 Defect rate (%) 0.5 2.1 11.4 18.3 75.0 Number of gaps (roots) 0.2 0 0.4 0.2 0.2

[0157] [Table 2-4] Table 2-4 See Example 3a See Example 3b Glass yarn The number of slipped filaments (pieces) measured from point T0. 5-10 5-10 Manufacturing conditions Loom speed (rpm) 450 450 Water pressure during high-pressure fiber opening (kg / cm) 2 ) 5.0 12.0 Evaluation results Fiberglass cloth thickness (μm) 29 29 Defect rate (%) 0.9 2.1 Number of gaps (roots) 5 3

[0158] [Table 2-5] Table 2-5 Example 11 Example 12 Comparative Example 9 Example 13 Comparative Example 10 Glass yarn The number of slipped filaments (pieces) measured from point T0. 0~1 2-3 4 0~3 4 Manufacturing conditions Loom speed (rpm) 450 450 450 450 450 Water pressure during high-pressure fiber opening (kg / cm) 2 ) 4.0 4.0 4.0 10.0 10.0 Evaluation results Fiberglass cloth thickness (μm) twenty one twenty one twenty one twenty one twenty one Defect rate (%) 0.8 1.5 5.6 2.2 15.0 Number of gaps (roots) 1.0 1.4 1.2 0.2 0.4

[0159] [Table 2-6] Table 2-6 Example 14 Example 15 Comparative Example 11 Example 16 Comparative Example 12 Glass yarn The number of slipped filaments (pieces) measured from point T0. 0~1 2-3 4 0~3 4 Manufacturing conditions Loom speed (rpm) 450 450 450 450 450 Water pressure during high-pressure fiber opening (kg / cm) 2 ) 6.0 6.0 6.0 12.0 12.0 Evaluation results Fiberglass cloth thickness (μm) 46 46 46 46 46 Defect rate (%) 0.0 0.6 0.7 0.8 3.8 Number of gaps (roots) 4.4 5.0 4.6 1.0 1.2

[0160] [Table 2-7] Table 2-7 Example 17 Example 18 Comparative Example 13 Example 19 Comparative Example 14 Glass yarn The number of slipped filaments (pieces) measured from point T0. 0~1 2-3 4 0~3 4 Manufacturing conditions Loom speed (rpm) 450 450 450 450 450 Water pressure during high-pressure fiber opening (kg / cm) 2 ) 5.0 5.0 5.0 12.0 12.0 Evaluation results Fiberglass cloth thickness (μm) 31 31 31 31 31 Defect rate (%) 0.2 1.2 4.3 2.5 18.0 Number of gaps (roots) 2.0 1.8 2.6 0.2 0.2

[0161] [Table 2-8] Table 2-8 Reference example 1a See Example 1b Glass yarn The number of slipped filaments (pieces) measured from point T0. 5-10 5-10 Manufacturing conditions Loom speed (rpm) 450 450 Water pressure during high-pressure fiber opening (kg / cm) 2 ) 7.0 12.0 Evaluation results Fiberglass cloth thickness (μm) 73 73 Defect rate (%) 0.9 2.7 Number of gaps (roots) 7.6 4.2

[0162] [Table 2-9] Table 2-9 See Example 2a See Example 2b Glass yarn The number of slipped filaments (pieces) measured from point T0. 5-10 5-10 Manufacturing conditions Loom speed (rpm) 450 450 Water pressure during high-pressure fiber opening (kg / cm) 2 ) 7.0 12.0 Evaluation results Fiberglass cloth thickness (μm) 89 89 Defect rate (%) 0.6 1.6 Number of gaps (roots) 8.4 4.6

[0163] Examples 1-4, 11, 12, 14, 15, 17, and 18 yielded glass cloths with excellent fuzz quality. In these examples, the number of slipped filaments measured from the starting point T0 of the glass yarn used was 3 or less, therefore it is presumed that the overall number of slipped filaments of the glass yarn wound throughout the bobbin is relatively small. It can be confirmed that glass cloths with excellent fuzz quality can be obtained by using this type of glass yarn.

[0164] In Examples 5-8, even if the loom speed is increased from 450 rpm to 550 rpm or 600 rpm in the weaving step to improve productivity, the quality of the fibers does not decrease significantly, and glass cloth with relatively good fiber quality is obtained.

[0165] In Examples 9, 10, 13, 16 and 19, by increasing the water pressure of the high-pressure water spray, a low dielectric glass cloth was obtained that maintained relatively good feather quality and improved impregnation.

[0166] On the other hand, the glass cloth obtained in Comparative Examples 1-3, Comparative Example 9, Comparative Example 11 and Comparative Example 13 had poor fiber quality.

[0167] Furthermore, in Comparative Examples 4 to 8, 10, 12 and 14, if the loom speed is increased from 450 rpm to 550 rpm or 600 rpm in the weaving step, or the water pressure of the high-pressure water spray is increased in the fiber opening step, then glass cloth with significantly poor hair quality is obtained.

[0168] In Reference Examples 1 (a, b) and 2 (a, b), if the thicknesses are 73 μm and 89 μm respectively, they are less than the thickness of the glass cloth in Examples 1 to 16.

[0169] Reference Example 3 (a, b) using E glass yarn yielded glass cloth with relatively good hair quality. Low-dielectric glass yarn of the same grade as Texa tends to have a higher number of slipped filaments, which can lead to a decrease in hair quality due to increased spray pressure from the high-pressure water jet (Comparative Examples 1-3, 6-8). In contrast, based on the results of Reference Example 3, no such tendency was observed with E glass yarn.

[0170] The following results were obtained in Examples 1-4 and Comparative Examples 1-3: Compared with "bore appearance inspection" and "number of hairs generated by applying load to glass yarn", "number of slipped filaments" is more reflective of the hair quality of glass cloth.

Claims

1. A glass cloth, which is made by using a glass yarn containing multiple glass filaments for warp and weft yarns, and 500 m in the length direction of the above glass cloth as an object, irradiating white LED light along its cloth surface, and observing every 1 m in the length direction, in the case of the presence of the entire surface of the cloth surface, counts as the number of defects. Defect rate (%) = (total of count values ​​of defects / 500) × 100.

2. The glass cloth of claim 1, wherein the entire surface hair plumes comprise 200 to 1000 μm of hair observed on the surface of the fabric using an optical microscope due to the breakage of the said filament.

3. The glass cloth of claim 1, wherein the thickness of the said glass cloth is 10 to 50 μm.

4. As in the glass cloth of claim 1, which contains the said glass yarn that satisfies the following conditions: (i) Tess (TEX) is 1 to 13, (ii) the breaking strength is 0.50 to 0.80 N / tex, and (iii) the number of filaments in which slippage more than 2 times the average value of the yarn width occurs at 180 m determination is less than 3.

5. In the case of the glass cloth of claim 1, which contains the said glass yarn with an adder spacing length of 1.8 to 10.0 cm.

6. For the glass cloth of claim 1, the difference between the maximum value of the length of the pinned interval and the minimum value of the length of the pinned interval containing the above glass yarn is divided by the average value of the pinned spacing length (the pinned spacing length difference index) of the said glass yarn of less than 0.

7.

7. If the glass cloth of any one of claims 1 to 6, wherein the said glass yarn having a length of more than 10,000 m is the object, when a determination range of 180 m in the length direction is selected separately at 5 sites that are different from each other, the number of filaments in which slippage of more than 2 times the average value of the yarn width occurs in each of the determination ranges of the 5 sites above is less than 3.

8. If the glass cloth of any one of claims 1 to 6, wherein the said glass yarn having a length of more than 50,000 m is the object, when a determination range of 180 m in the length direction is selected separately at 7 sites that are different from each other, the number of filaments in which slippage of more than 2 times the average value of the yarn width occurs in each of the determination ranges of the 7 sites above is less than 3.

9. If the glass cloth of any one of claims 1 to 6, wherein the said glass yarn having a length of more than 100,000 m is the object, when a determination range of 180 m in the length direction is selected separately at 10 sites that are different from each other, the number of filaments in which slippage of more than 2 times the average value of the yarn width occurs in each of the determination ranges of the above 10 sites is less than 3.

10. A method of manufacture of glass cloth, which includes the step of weaving by using a glass yarn containing multiple strands of glass filament for warp and weft yarn, and (i) the tex of the said glass yarn is 1 to 13, (ii) the breaking strength of the said glass yarn is 0.50 to 0.80 N / tex, and (iii) at 180 m the above 3 filaments of the yarn width are less than 2 times the average of the yarn width.

11. As for the method of manufacturing the glass cloth of claim 10, wherein the means of the said glass yarn are 1 to 7.

12. The method of manufacturing the glass cloth of claim 10, wherein the number of single glass filaments constituting the said glass yarn is 30 to 120.

13. The method of manufacturing the glass cloth of claim 10, wherein the length of the splint spacing of the said glass yarn is 1.8 to 10.0 cm.

14. As in the method of manufacture of glass cloth of claim 10, wherein the difference between the maximum value and the minimum value of the length of the pinning interval of the above glass yarn is divided by the average of the length of the pinning interval (the value of the pinning interval length difference index) is less than 0.

7.

15. If the method of manufacturing the glass cloth of claim 10, wherein the density of the said glass yarn is 2.2 g / cm 3 or more and does not reach 2.5 g / cm 3 .

16. The method of manufacturing the glass cloth of claim 10, wherein the coefficient of elasticity of the said glass yarn is 50 to 70 GPa.

17. The method of manufacturing the glass cloth of claim 10, wherein the coefficient of elasticity of the said glass yarn is 50 to 63 GPa.

18. If the method of manufacturing glass cloth of any one of claims 10 to 17, wherein the said glass yarn having a length of 10,000 m or more is the object, when a determination range of 180 m in the length direction is selected separately at 5 sites that are different from each other, the number of filaments in which slippage of more than 2 times the average value of the yarn width occurs in each of the ranges of the 5 sites above is less than 3.

19. If the method of manufacturing glass cloth of any one of claims 10 to 17, wherein the said glass yarn having a length of 50,000 m or more is the object, when a determination range of 180 m in the length direction is selected separately at 7 sites that are different from each other, the number of filaments in which slippage more than 2 times the average value of the yarn width occurs in each of the determination ranges of the 7 sites is less than 3.

20. If the method of manufacturing glass cloth of any one of claims 10 to 17, wherein the above-mentioned glass yarn having a length of more than 100,000 m is the object, when a determination range of 180 m in the length direction is selected separately at 10 sites that are not identical to each other, the number of filaments that slip more than 2 times the average value of the yarn width occurs in each of the ranges of the above 10 sites is 3.

21. A glass yarn in which (i) the tex is 1–13, (ii) the breaking strength is 0.50–0.80 N / tex, and (iii) the number of filaments that occur more than 2 times the average value of the yarn width at 180 m determination is less than 3 filaments.

22. As in the glass yarn of claim 21, wherein the said tees are 1 to 7.

23. As in the glass yarn of claim 21, wherein the number of single glass filaments constituting the said glass yarn is 30 to 120.

24. As in the glass yarn of claim 21, wherein the length of the splint spacing is 1.8 to 10.0 cm.

25. As in the glass yarn of Requisition 21, where the difference between the maximum value of the length of the adder interval and the minimum value of the length of the adder interval is obtained by dividing the value of the average of the length of the adder interval (the index of length difference between the adder interval) is less than 0.

7.

26. The glass yarn of claim 21 has a density of 2.2 g / cm 3 or more and not reaching 2.5 g / cm 3 .

27. Such as the glass yarn of claim 21, wherein the coefficient of elasticity is 50 to 70 GPa.

28. Such as the glass yarn of claim 21, wherein the coefficient of elasticity is 50 to 63 GPa.

29. If the glass yarn of any one of claims 21 to 28, wherein the said glass yarn having a length of more than 10,000 m is the object, when a determination range of 180 m in the length direction is selected separately at 5 sites that are different from each other, the number of filaments in which slippage of more than 2 times the average value of the yarn width occurs in each of the range of determination of the 5 sites above is less than 3.

30. If a glass yarn of any one of claims 21 to 28, wherein the said glass yarn having a length of more than 50,000 m is the object, when a determination range of 180 m in the length direction is selected separately at 7 sites that are different from each other, the number of filaments in which slippage of more than 2 times the average value of the yarn width occurs in each of the determination ranges of the said 7 sites is less than 3.

31. If the glass yarn of any one of claims 21 to 28, wherein the said glass yarn having a length of more than 100,000 m is the object, when a determination range of 180 m in the length direction is selected separately at 10 sites that are different from each other, the number of filaments that slip more than 2 times the average value of the yarn width occurs in each of the ranges of the 10 sites above.

Images