Manufacturing method of glass yarn and glass cloth, and glass cloth

Abstract

A method for manufacturing glass yarn and glass cloth, and a glass cloth. The object of the present invention is to provide a method for stably manufacturing a low-dielectric glass cloth with good quality, an inspection method therefor, and a glass yarn suitable for stably producing a low-dielectric glass cloth. There is provided a method for manufacturing a glass cloth, which is a method for manufacturing a glass cloth having a glass yarn package body used for warp and weft and a thickness of 10 μm or more and 35 μm or less, wherein the glass yarn package body has a TEX of 1.0 g / 1000 m or more and 5.6 g / 1000 m or less, and the Si content in the glass composition is 0 mass% or more and 60 mass% or less in terms of SiO 2 calculated as, and the B content is 15 mass% or more and 30 mass% or less in terms of B 2 O 3 calculated as, and the glass yarn is wound around a bobbin. The sizing agent coating amount of the glass yarn is 0.5 mass% or more and 1.2 mass% or less, and the surface average hardness of the glass yarn package body is 68 or more and 86 or less.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing glass yarn and glass cloth, and a glass cloth. Background Art

[0002] With the development of the information and communication society in recent years, data communication and / or signal processing have gradually been carried out in a large capacity and at high speed. For example, the reduction of the dielectric constant of printed circuit boards used in communication devices or measuring instruments such as high-end servers, high-end routers / switches, supercomputers, and base stations has been significantly promoted. Therefore, various low-dielectric glass cloths have also been proposed for the glass cloth constituting the printed circuit board.

[0003] For example, the low-dielectric glass cloth disclosed in Patent Document 1 achieves a low dielectric constant by blending a large amount of B 2 O 3 in the glass composition of the conventionally commonly used E glass cloth, and at the same time adjusting the blending amounts of other components such as SiO 2 .

[0004] In addition, for terminal electronic devices such as smartphones, it is also required to cope with high-speed / large-capacity communication. Therefore, recently, a rapid advancement in the reduction of the dielectric constant of printed circuit boards used in mother board substrates or semiconductor substrates for smartphones has been observed. Therefore, there is a strong demand for a thin and light low-dielectric glass cloth with a thickness of 10 to 35 μm.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2010-508226

[0008] Patent Document 2: Japanese Patent Application Laid-Open No. 2000-191341

[0009] Patent Document 3: Japanese Patent Application Laid-Open No. 2002-293577

[0010] Patent Document 4: Japanese Patent Application Laid-Open No. 2003-34556

[0011] Patent Document 5: Japanese Patent Application Laid-Open No. 2004-262713

[0012] Patent Document 6: International Publication No. 2013 / 081108 Summary of the Invention

[0013] Problems to be Solved by the Invention

[0014] When the present inventors conducted research, they learned that: compared with the E-glass cloth that has been used all along, there are significant deviations in the performance or quality of the low-dielectric glass cloth made of glass yarns that have been subjected to low-dielectrification as described in Patent Document 1. In particular, the low-dielectric constant glass cloth with a thickness as thin as 10 to 35 μm is difficult to produce stably because the strength of the low-dielectric glass yarns that make it up is weak and the hygroscopicity is high, and the deviation in quality is significant. Such quality deviations in the glass cloth also affect the quality of prepregs, laminated boards for printed circuit boards, etc. obtained by using it.

[0015] For example, Patent Documents 2 to 6, etc. disclose methods of studying starting from the sizing agent coated on the surface of glass yarns for the purpose of improving the fluffing, fly-away property, and degreasing property of the glass yarns used to manufacture glass cloth. However, at present, in order to stably produce low-dielectric glass cloth with good quality, further research and improvement are required.

[0016] The present invention has been made in view of the above problems, and its object is to provide a method for stably manufacturing a low-dielectric glass cloth with good quality, an inspection method therefor, and a glass yarn suitable for stably producing a low-dielectric glass cloth.

[0017] Solutions for Solving the Problems

[0018] The present inventors conducted in-depth research to solve the above problems, and as a result, found that: by using glass yarns with a sizing agent coating amount and surface characteristics after coating the sizing agent within a specific range to manufacture a glass cloth, it is possible to stably manufacture a low-dielectric glass cloth with a thickness as thin as 10 to 35 μm with good quality, and thus the present invention was completed. The following lists one aspect of the present invention.

[0019] <1>A method for manufacturing a glass cloth, which is a method for manufacturing a glass cloth that uses a glass yarn package for warp and weft yarns and has a thickness of 10 μm or more and 35 μm or less. The glass yarn package is obtained by winding glass yarns with a TEX of 1.0 g / 1000 m or more and 5.6 g / 1000 m or less, an Si content in the glass composition of 40 mass% or more and 60 mass% or less in terms of SiO 2 conversion, and a B content of 15 mass% or more and 30 mass% or less in terms of B 2 O 3 conversion around a bobbin.

[0020] The sizing agent coating amount of the aforementioned glass yarn is 0.5 mass% or more and 1.2 mass% or less, and

[0021] The average surface hardness of the aforementioned glass yarn package is 68 or more and 86 or less.

[0022] <2>The manufacturing method of the glass cloth according to Item 1, wherein the water droplet penetration time when dropping 2 ml of water droplets onto the aforementioned glass yarn package is 20 seconds or more and 300 seconds or less.

[0023] <3>The manufacturing method of the glass cloth according to Item 1 or 2, wherein the strong heat heating weight loss of the aforementioned glass yarn is 0.8 mass% or more and less than 1.5 mass%.

[0024] <4>The manufacturing method of the glass cloth according to any one of Items 1 to 3, wherein the aforementioned glass yarn is a glass yarn obtained by bundling 80 or more and 120 or less glass filaments with an average diameter exceeding 4.7 μm and being 5.5 μm or less, the average value of the yarn width when measured at 50 m is 95 μm or more and 125 μm or less, and when measured at 50 m, 98.0% or more in the length direction is composed of a yarn width of 220 μm or less.

[0025] <5>The manufacturing method of the glass cloth according to any one of Items 1 to 3, wherein the aforementioned glass yarn is a glass yarn obtained by bundling 80 or more and 120 or less glass filaments with an average diameter exceeding 4.3 μm and being 4.7 μm or less, the average value of the yarn width when measured at 50 m is 80 μm or more and 115 μm or less, and when measured at 50 m, 98.0% or more in the length direction is composed of a yarn width of 190 μm or less.

[0026] <6>The manufacturing method of the glass cloth according to any one of Items 1 to 3, wherein the aforementioned glass yarn is a glass yarn obtained by bundling 40 or more and 120 or less glass filaments with an average diameter of 3.5 μm or more and 4.3 μm or less, the average value of the yarn width when measured at 50 m is 70 μm or more and 105 μm or less, and when measured at 50 m, 98.0% or more in the length direction is composed of a yarn width of 170 μm or less.

[0027] <7>A glass yarn, which has a TEX of 1.0 g / 1000 m or more and 5.6 g / 1000 m or less, the Si content in the glass composition is 40 mass% or more and 60 mass% or less in terms of SiO 2 conversion, and the B content is 15 mass% or more and 30 mass% or less in terms of B 2 O 3 conversion, and the sizing agent coating amount of the aforementioned glass yarn is 0.5 mass% or more and 1.2 mass% or less,

[0028] the aforementioned glass yarn is in a state of being wound around a bobbin in the form of a glass yarn package, and

[0029] the surface average hardness of the aforementioned glass yarn package is 68 or more and 86 or less.

[0030] ​

[0031] <8>The glass yarn according to Item 7, wherein the water droplet penetration time when 2 ml of water droplets are dropped onto the glass yarn package is 20 seconds or more and 300 seconds or less.

[0032] <9>The glass yarn according to Item 7 or 8, wherein the strong heat heating weight loss of the glass yarn is 0.8 mass% or more and less than 1.5 mass%.

[0033] <10>The glass yarn according to any one of Items 7 to 9, wherein the glass yarn is a glass yarn obtained by bundling 80 or more and 120 or less glass filaments with an average diameter exceeding 4.7 μm and being 5.5 μm or less. The average value of the yarn width measured at 50 m is 95 μm or more and 125 μm or less. When measured at 50 m, 98.0% or more in the length direction is composed of a yarn width of 220 μm or less.

[0034] <11>The glass yarn according to any one of Items 7 to 9, wherein the glass yarn is a glass yarn obtained by bundling 80 or more and 120 or less glass filaments with an average diameter exceeding 4.3 μm and being 4.7 μm or less. The average value of the yarn width measured at 50 m is 80 μm or more and 115 μm or less. When measured at 50 m, 98.0% or more in the length direction is composed of a yarn width of 190 μm or less.

[0035] <12>The glass yarn according to any one of Items 7 to 9, wherein the glass yarn is a glass yarn obtained by bundling 40 or more and 120 or less glass filament bundles with an average diameter of 3.5 μm or more and 4.3 μm or less. The average value of the yarn width measured at 50 m is 70 μm or more and 105 μm or less. When measured at 50 m, 98.0% or more in the length direction is composed of a yarn width of 170 μm or less.

[0036] <13>A glass yarn package, which is a glass yarn package obtained by winding a glass yarn with a TEX of 1.0 g / 1000 m or more and 5.6 g / 1000 m or less, an Si content in the glass composition of 40 mass% or more and 60 mass% or less in terms of SiO 2 conversion, and a B content of 15 mass% or more and 30 mass% or less in terms of B 2 O 3 conversion on a bobbin,

[0037] the sizing agent coating amount of the glass yarn is 0.5 mass% or more and 1.2 mass% or less, and

[0038] the surface average hardness of the glass yarn package is 68 or more and 86 or less.

[0039] <14>The glass yarn package according to Item 13, wherein the water droplet penetration time when 2 ml of water droplets are dropped onto the aforementioned glass yarn package is 20 seconds or more and 300 seconds or less.

[0040] <15>The glass yarn package according to Item 13 or 14, wherein the strong heat heating weight loss of the aforementioned glass yarn is 0.8 mass% or more and less than 1.5 mass%.

[0041] <16>A method for inspecting a glass yarn package, which is a method for inspecting a glass yarn package used for warp and weft yarns and having a thickness of 10 μm or more and 35 μm or less. The glass yarn package is obtained by winding a glass yarn having a TEX of 1.0 g / 1000 m or more and 5.6 g / 1000 m or less, an Si content of 40 mass% or more and 60 mass% or less in terms of SiO 2 conversion, and a B content of 15 mass% or more and 30 mass% or less in terms of B 2 O 3 conversion around a bobbin.

[0042] The inspection method determines the quality of the glass yarn package in which the sizing agent coating amount of the aforementioned glass yarn is 0.5 mass% or more and 1.2 mass% or less, and the surface average hardness of the aforementioned glass yarn package is 68 or more and 86 or less.

[0043] Effects of the Invention

[0044] According to the present invention, a method for stably producing a low-dielectric glass cloth with good quality, and a glass yarn or a glass yarn package suitable for stably producing a low-dielectric glass cloth with good quality can be provided. In relation to the stable production of good quality, the storage stability of the glass yarn and the flying-away stability over time are excellent. Furthermore, an inspection method capable of discriminating the quality of the glass yarn package can also be provided. Detailed Description of the Invention

[0045] Hereinafter, the embodiments of the present invention (hereinafter referred to as "the present embodiments") will be described in detail, but the present invention is not limited thereto, and various modifications can be made without departing from the gist thereof.

[0046] 〔Method for Manufacturing Glass Cloth〕

[0047] The method for manufacturing the glass cloth of the present embodiment is a method for manufacturing a glass cloth having a thickness of 10 μm or more and 35 μm or less, and is characterized in that it uses a glass yarn having a TEX of 1.0 g / 1000 m or more and 5.6 g / 1000 m or less, an Si content of 40 mass% or more and 60 mass% or less in terms of SiO 2 conversion, and a B content of 15 mass% or more and 30 mass% or less in terms of B 2 O3 A method for manufacturing a glass cloth woven with glass yarns having a sizing agent coating amount of 0.5% by mass or more and 1.2% by mass or less, a surface average hardness of 68 or more and 86 or less, and a conversion count of 15% by mass or more and 30% by mass or less as warp and weft yarns, which is supplied for warping and weaving in the form of a glass yarn package wound around a bobbin.

[0048] 〔Low-dielectric glass yarn and glass cloth thickness〕

[0049] In the past, it was considered that it was difficult to stably manufacture a high-quality low-dielectric glass cloth with a thickness of 35 μm or less using fine low-dielectric glass yarns compared to a glass cloth with a thickness exceeding 35 μm manufactured using coarser glass yarns. The reason is not limited, but it can be considered as follows.

[0050] The low-dielectric glass yarn used to manufacture the low-dielectric glass cloth contains a large amount of B compared to the E glass yarn used in the past. 2 O 3 components with hygroscopic properties such as these, and thus the glass yarn itself has the characteristic of high hygroscopicity. On top of this, the sizing agent applied to the glass yarn for the purpose of protecting the glass yarn from mechanical loads has mainly been hydrophilic polymer components such as starch, so the hygroscopicity of the glass yarn itself and the hygroscopicity brought about by the sizing agent act synergistically, and there is a tendency for the hygroscopicity of the low-dielectric glass yarn to become high.

[0051] Furthermore, the low-dielectric glass yarn has a weaker mechanical strength compared to the conventional E glass, so there is a tendency to apply more sizing agent compared to the conventional E glass yarn for the purpose of protecting and compensating for it. Also, the fine yarns used in a glass cloth with a thickness of 35 μm or less tend to have a weaker mechanical strength and more sizing agent applied.

[0052] By operating in this way, the fine low-dielectric glass yarns used in a glass cloth with a thickness of 35 μm or less are significantly affected by the hygroscopic characteristics brought about by the sizing agent in addition to the hygroscopic characteristics of the glass yarn itself, presenting a state of extremely high hygroscopicity.

[0053] It can be considered that: the sized glass yarn that has absorbed moisture lacks lubricity, and the function of the sizing agent to inhibit the friction between fiber filaments will not work effectively. Therefore, due to internal stresses such as winding tightness in the state of being wound around a bobbin, shear stress acts between the fiber filaments, and filament breakage is likely to occur. Additionally, it can be considered that: even in the unwinding stage from the bobbin during the warping process and the weaving process, the function of the sizing agent to inhibit the friction between fiber filaments will not work effectively. Therefore, filament breakage accompanied by the friction between the glass yarn bundle and the glass fiber filaments is likely to occur. Furthermore, it can be considered that: during the storage period of the glass yarn, moisture absorption of the sizing agent of the glass yarn and moisture absorption of the glass yarn itself through the sizing agent will also occur. Therefore, the glass yarn that has absorbed moisture and lacks lubricity presents the following state: filament breakage inside the bobbin and filament breakage during the unwinding process from the bobbin are more likely to occur. Therefore, depending on the storage state or storage period of the glass yarn, there is a problem that the fluff quality of the obtained glass cloth deteriorates significantly.

[0054] Additionally, it can be considered that: during the storage period of the glass yarn, if the sizing agent of the glass yarn absorbs moisture, the oil component in the sizing agent separates and transfers to the surface, increasing the viscosity of the glass yarn surface. Therefore, the unwinding tension when unwinding the glass yarn from the bobbin or the contact resistance with the yarn guide in the yarn path during the handling of the glass yarn increases, and the flying stability of the weft yarn decreases significantly. Therefore, depending on the storage period of the glass yarn, there are the following problems: the deviation of the arrival angle of the weft yarn becomes larger, and weaving defects such as loom stops and weft yarn slack caused by missing wefts of the weft yarn increase. Additionally, depending on the storage period of the glass yarn, there is a problem that warp breakage is likely to occur during the warping process of the warp yarn.

[0055] In contrast, in the present embodiment, by setting the coating amount of the sizing agent applied to the low-dielectric glass yarn and the surface characteristics of the package after applying the sizing agent within a specific range, moisture absorption of the low-dielectric glass yarn is suppressed, and attenuation of the lubricity and increase in the viscosity of the glass yarn can be prevented. Thereby, good fluff quality and stable flying performance of the glass yarn can be obtained, and low-dielectric glass cloth can be stably manufactured with good quality.

[0056] (Composition of glass yarn)

[0057] The glass yarn for manufacturing glass cloth is obtained by bundling and twisting multiple glass filaments. In this case, the glass yarns are classified as multifilaments respectively, and the glass filaments are classified as monofilaments.

[0058] The average diameter of the glass filaments constituting the warp and weft yarns is independently, for example, more than 4.7 μm and 5.5 μm or less, more than 4.3 μm and 4.7 μm or less, or more than 3.5 μm and 4.3 μm or less. By making the average diameter of the glass filaments 5.5 μm or less, the processability is further improved, and a printed circuit board with thin and high-density mounting can be achieved.

[0059] Examples of the elements constituting the glass yarn include Si, B, Al, Ca, Mg, P, Na, K, Ti, Zn, Fe, F, etc.

[0060] The Si content of the glass yarn is 40 to 60% by mass in terms of SiO 2 conversion, preferably 45 to 55% by mass, more preferably 47 to 53% by mass, and further preferably 48.0 to 53% by mass. Si is a component that forms the framework structure of the glass yarn. By making the Si content 40% by mass or more, the strength of the glass yarn is further improved, and the fuzzing of the glass cloth can be suppressed. In addition, by making the Si content 40% by mass or more, there is a tendency for the dielectric constant of the glass cloth to be further reduced. On the other hand, by making the Si content 60% by mass or less, there is a tendency in the manufacturing process of the glass filaments that the viscosity during melting is further reduced, and glass fibers with a more uniform glass composition can be obtained. Therefore, the obtained glass filaments are not likely to have regions where devitrification is likely to occur locally or regions where bubbles are difficult to remove locally. As a result, the glass filaments are not likely to have regions with weak local strength, and thus, the fuzzing of the glass cloth can be suppressed. The Si content can be adjusted according to the amount of raw materials used to make the glass filaments.

[0061] The B content of the glass yarn is 15 to 30% by mass in terms of B 2 O 3 conversion. The preferred range of the B content of the glass yarn is 17% by mass or more and 28% by mass or less, more preferably more than 19.5% by mass and 27% by mass or less, or 20% by mass or more and 30% by mass or less, further preferably more than 20% by mass and 25% by mass or less, and even more preferably 21% by mass or more and 24% by mass or less. By making the B content 15% by mass or more, there is a tendency for the dielectric constant to be further reduced. However, by making the B content 15% by mass or more, the hygroscopicity of the glass yarn increases, and it is difficult to stably manufacture the glass cloth with good quality. Therefore, it is very useful to suppress the sizing agent coating amount in this embodiment and the hygroscopicity of the glass yarn as the surface characteristics after coating the sizing agent. In addition, by making the B content 30% by mass or less, there is a tendency for the moisture resistance to be improved and the insulation reliability to be further improved. The B content can be adjusted according to the amount of raw materials used to make the glass filaments. It should be noted that when there may be variations in the production of glass filaments, the raw material feeding amount can be adjusted by predicting it in advance.

[0062] The Al content of the glass yarn, calculated as Al 2 O 3 is preferably 11 to 18% by mass, more preferably 11 to 16% by mass, and still more preferably 12 to 16% by mass. By making the Al content within the above range, there is a tendency for further improvement in electrical properties and strength. The Al content can be adjusted according to the amount of raw materials used to produce the glass filaments.

[0063] The Ca content of the glass yarn, calculated as CaO, is preferably 5 to 10% by mass, more preferably 5 to 9% by mass, and still more preferably 5 to 8.5% by mass. By making the Ca content 5% by mass or more, there is a tendency during the production of the glass filaments for the viscosity during melting to further decrease, and glass fibers with a more uniform glass composition can be obtained. In addition, by making the Ca content 10% by mass or less, there is a tendency for the dielectric constant to further increase. The Ca content can be adjusted according to the amount of raw materials used to produce the glass filaments.

[0064] It should be noted that the above-mentioned respective contents can be measured by ICP emission spectrometry. Specifically, the Si content and the B content can be obtained as follows: After weighing a glass cloth sample and melting it with sodium carbonate, it is dissolved with dilute nitric acid and made up to volume, and the resulting sample is measured by ICP emission spectrometry to obtain the contents. In addition, the Fe content can be obtained as follows: The weighed glass cloth sample is dissolved and made up to volume by an alkali dissolution method, and the resulting sample is measured by ICP emission spectrometry to obtain the content. Furthermore, the Al content, the Ca content, the P content, and the Mg content can be obtained as follows: After heating and decomposing the weighed glass cloth sample with perchloric acid, sulfuric acid, nitric acid, and hydrogen fluoride, it is dissolved with dilute nitric acid and made up to volume, and the resulting sample is measured by ICP emission spectrometry to obtain the contents. As the ICP emission spectrometry apparatus, PS3520VDDII manufactured by Hitachi High-Technologies Corporation can be used.

[0065] (TEX of the glass yarn)

[0066] The TEX of the glass yarn is 1.0 g / 1000 m or more and 5.6 g / 1000 m or less, preferably 1.2 g / 1000 m or more and 5.4 g / 1000 m or less or 2.4 g / 1000 m or more and 5.4 g / 1000 m or less, more preferably 1.4 g / 1000 m or more and 5.2 g / 1000 m or less, and still more preferably 2.0 g / 1000 m or more and 5.0 g / 1000 m or less.

[0067] When the TEX of the glass yarn is at the above lower limit or more, if B in the glass composition 2 O 3If the content, the coating amount of the sizing agent, and the surface characteristics of the glass yarn package are within the scope of the present invention, the moisture absorption of the glass yarn is suppressed, and the lubricity of the glass yarn can be maintained. Therefore, regardless of the storage state and storage period of the glass yarn, glass cloth can be stably manufactured, and it is also suitable as an inspection method for the glass yarn package.

[0068] When the TEX of the glass yarn is below the above upper limit, the processability of the glass cloth is improved, and a glass cloth with a thickness of 35 μm or less can be produced. Therefore, a printed circuit board with a thin and high-density installation can be realized, and it is also suitable as an inspection method for the glass yarn package.

[0069] (Coating amount of sizing agent)

[0070] The coating amount of the sizing agent on the glass yarn is 0.5% by mass or more and 1.2% by mass or less. The preferred range of the coating amount of the sizing agent is 0.6% by mass or more and 1.2% by mass or less, the more preferred range is 0.7% by mass or more and 1.15% by mass or less, and the further preferred range is 0.7% by mass or more and 1.1% by mass or less.

[0071] The coating amount of the sizing agent on the glass yarn can be obtained by, for example, separating and extracting the sizing agent from the glass yarn using the specific method shown below.

[0072] Specific method:

[0073] (1) Weigh about 3 g of glass yarn to the nearest 0.0001 g to obtain the weight α (g) of the glass yarn.

[0074] (2) Add 70 ml of hot water at 80 °C, and stir for 15 minutes while performing ultrasonic treatment.

[0075] (3) Separate the glass yarn and the hot water extract by decantation to obtain the hot water extract 1.

[0076] (4) Add 70 ml of hot water at 80 °C to the remaining glass yarn, and stir for 15 minutes while performing ultrasonic treatment.

[0077] (5) Separate the glass yarn and the hot water by decantation to obtain the hot water extract 2.

[0078] (6) Add 70 ml of acetone to the remaining glass yarn and stir for 15 minutes.

[0079] (7) Separate the glass yarn and the acetone extract by decantation to obtain the acetone extract.

[0080] (8) Add 70 ml of hexane to the remaining glass yarn and stir for 15 minutes.

[0081] (9) The glass yarn and the hexane extract are separated by decantation to obtain the hexane extract.

[0082] (10) The obtained hot water extract 1, hot water extract 2, acetone extract and hexane extract are combined. After removing the fragments of the glass yarn mixed therein, they are completely dried to obtain the extracted sizing agent in the form of dry solids.

[0083] (11) Weigh the weight β (g) of the extracted sizing agent with an accuracy of 0.0001 g.

[0084] (12) According to the weight α (g) of the glass yarn and the weight β (g) of the extracted sizing agent, the sizing agent coating amount of the glass yarn is calculated using the following formula.

[0085] Sizing agent coating amount (%) = {β (g) / α (g)} × 100

[0086] If the sizing agent coating amount of the glass yarn is above the lower limit value of the above range, appropriate lubricity is imparted to the glass yarn. Therefore, in the manufacturing process of the glass yarn and the process of manufacturing a glass cloth using the glass yarn, the friction between the glass yarns or between the glass yarn and the weaving mechanism components such as the yarn guide can be suppressed. Thus, fuzzing is suppressed, and a glass cloth with excellent fluff quality can be obtained, which is also suitable as an inspection method for the glass yarn package.

[0087] If the sizing agent coating amount of the glass yarn is below the upper limit value of the above range, the moisture absorption of the glass yarn is suppressed. Therefore, the attenuation of the lubricity and the increase in viscosity of the glass yarn can be prevented. As a result, regardless of the storage conditions and storage period of the glass yarn, stable fluff quality and flying characteristics can be obtained. Therefore, a low dielectric glass cloth with excellent quality can be stably manufactured, which is also suitable as an inspection method for the glass yarn package.

[0088] (Strong heat heating loss of glass yarn)

[0089] The strong heat heating loss of the glass yarn is 0.8 mass% or more and less than 1.5 mass%. The preferred range of the strong heat heating loss is 0.9 mass% or more and 1.45 mass% or less, and the more preferred range is 1.0 mass% or more and 1.4 mass% or less.

[0090] The strong heat heating loss of the glass yarn is the value obtained in the form of the weight loss ratio when subjected to a heat treatment at 625 ± 5 °C for 20 minutes in accordance with JIS3420.

[0091] It is speculated that perhaps because the glass yarn of the present invention is in accordance with B 2 O 3The converter contains a large amount of B in an amount of 15% by mass or more and 30% by mass or less. During the heat treatment at 625°C, weight loss also occurs in the fiberglass yarn itself. Therefore, the strong heat heating weight loss is a value that reflects the weight loss of the fiberglass yarn itself and the weight loss due to the combustion and removal of the sizing agent.

[0092] If the strong heat heating weight loss of the fiberglass yarn is above the lower limit value of the above range, it becomes an appropriate sizing agent coating amount for the B content range of the fiberglass yarn of the present invention. Therefore, moderate lubricity is imparted to the fiberglass yarn. Thus, during the manufacturing process of the fiberglass yarn and the process of manufacturing a glass cloth using the fiberglass yarn, friction between the fiberglass yarns or between the fiberglass yarn and weaving components such as yarn guides can be suppressed. Therefore, fuzzing is suppressed, and a glass cloth with excellent fluff quality can be obtained.

[0093] If the strong heat heating weight loss of the fiberglass yarn is below the upper limit value of the above range, it becomes an appropriate sizing agent coating amount for the B content range of the fiberglass yarn of the present invention. Therefore, moisture absorption of the fiberglass yarn can be suppressed. Thus, attenuation of the lubricity and increase in viscosity of the fiberglass yarn can be prevented. Thereby, regardless of the storage conditions and storage period of the fiberglass yarn, stable fluff quality and flying characteristics can be obtained. Therefore, a low dielectric glass cloth with excellent quality can be stably manufactured.

[0094] (Surface average hardness of the fiberglass yarn package)

[0095] The fiberglass yarn for manufacturing a glass cloth is supplied to the weaving process in the form of a fiberglass yarn package wound around a bobbin. The surface average hardness of the fiberglass yarn package is 68 or more and 86 or less. The preferred range of the surface average hardness of the fiberglass yarn package is 69 or more and 84 or less, the more preferred range is 70 or more and 82 or less, and the further preferred range is 75 or more and 80 or less.

[0096] If the surface average hardness of the fiberglass yarn package is above the lower limit of the above range, the collapse of the roll can be suppressed with respect to vibrations generated during transportation of the fiberglass yarn package, etc. If the surface average hardness of the fiberglass yarn package is below the upper limit of the above range, the shear force applied to the fiberglass yarn is small, and fuzzing of the fiberglass yarn can be suppressed. Therefore, a glass cloth with excellent fluff quality can be obtained. In addition, the surface average hardness within the above range is also suitable as a method for inspecting the quality of the fiberglass yarn package.

[0097] (Water droplet penetration time on the surface of the fiberglass yarn package)

[0098] Regarding the glass yarn used in this embodiment, from the perspective of easily exerting the effects of the present invention, within the above range of surface average hardness, when 2 ml of water droplets are dropped onto the glass yarn package, the water droplet penetration time is preferably 20 seconds or more and 300 seconds or less. A more preferable range of the water droplet penetration time is 25 seconds or more and 300 seconds or less, a further preferable range is 25 seconds or more and 270 seconds or less, and an even more preferable range is 25 seconds or more and 250 seconds or less. From the same perspective, the difference between the above water droplet penetration time of the glass yarn used in this embodiment and the water droplet penetration time after storing the package for 10 months is preferably within 100 seconds, more preferably within 50 seconds, and further preferably within 30 seconds. The storage method for 10 months at this time can use, for example, the method described in the examples.

[0099] The water droplet penetration time when 2 ml of water droplets are dropped onto the glass yarn package is an index reflecting the ease of wetting of water on the surface of the glass yarn. If it is easily wetted by water, the water droplet penetration time becomes shorter; if it is not easily wetted by water, the water droplet penetration time becomes longer.

[0100] The water droplet penetration time can be measured using, for example, the measurement method shown below.

[0101] Measurement method:

[0102] Place the glass yarn package horizontally along the transverse direction, drop 2 ml of water droplets onto the central part of the range where the glass yarn is wound, and calculate the time until the water droplets are impregnated and disappear. For one glass yarn package, change the position in the circumferential direction and perform 4 measurements, and calculate the average value of the 4 measurements.

[0103] If the water droplet penetration time when 2 ml of water droplets are dropped onto the glass yarn package is above the lower limit value of the above range, the moisture absorption of the glass yarn will be inhibited, and the loss of lubricity and the increase in viscosity caused by moisture absorption during storage of the glass yarn will be inhibited. Therefore, high-quality glass yarn can be stably produced regardless of the storage conditions and storage period of the glass yarn, and it is also suitable as a method for inspecting the quality of the glass yarn package.

[0104] If the water droplet penetration time when 2 ml of water droplets are dropped onto the glass yarn package is below the upper limit value of the above range, the glass yarn moderately has softness. Therefore, good flyability or fly stability can be obtained when the glass yarn is used as a weft yarn. In addition, in the general manufacturing process of glass cloth, the sizing agent is degummed by a combination of cleaning and removal treatment based on water and hot water and high-temperature heating treatment for combustion removal. If the water droplet penetration time is below the upper limit value of the above range, it is easy to clean and remove the sizing agent or the combustion residue of the sizing agent with water and hot water. Therefore, there is a tendency to be able to appropriately remove the sizing agent. Furthermore, the water droplet penetration time being below the upper limit value of the above range is suitable as a method for inspecting the quality of the glass yarn package.

[0105] The water droplet penetration time when 2 ml of water droplets are dripped onto the glass yarn package can be adjusted by the composition of the sizing agent and the coating method of the sizing agent.

[0106] (Water droplet contact angle on the surface of the glass yarn package)

[0107] In addition, the surface characteristics of the glass yarn package can also be observed using the water droplet contact angle. For example, within the above-mentioned range of average surface hardness, the contact angle observed 10 seconds after dripping 2 ml of water droplets onto the glass yarn package is 70° or more and 110° or less. The preferred range of the contact angle is 75° or more and 105° or less, and the more preferred range is 80° or more and 100° or less.

[0108] The contact angle when 2 ml of water droplets are dripped onto the glass yarn package is, like the water droplet penetration time when 2 ml of water droplets are dripped onto the glass yarn package, an index reflecting the ease of wetting of water on the surface of the glass yarn. If it is easily wetted by water, the contact angle becomes smaller, and if it is not easily wetted by water, the contact angle becomes larger.

[0109] The water droplet contact angle can be measured using, for example, the measurement method shown below.

[0110] Measurement method:

[0111] Place the glass yarn package horizontally along the transverse direction, drip 2 ml of water droplets onto the central part of the range where the glass yarn is wound, and measure the contact angle of the water droplets after 10 seconds. For one glass yarn package, change the position in the circumferential direction and perform 4 measurements, and calculate the average value of the 4 measurements.

[0112] If the contact angle when 2 ml of water droplets are dripped onto the glass yarn package is above the lower limit value of the above range, the moisture absorption of the glass yarn will be suppressed, and the loss of lubricity and the increase in viscosity caused by moisture absorption during the storage of the glass yarn will be suppressed. Therefore, regardless of the storage conditions and storage period of the glass yarn, high-quality glass yarn can be stably produced, and it is also suitable as an inspection method for the quality of the glass yarn package.

[0113] If the water droplet contact angle when 2 ml of water droplets are dripped onto the glass yarn package is below the upper limit value of the above range, the glass yarn moderately has softness. Therefore, when the glass yarn is used as a weft yarn, good flyability or fly stability can be obtained. In addition, in the general manufacturing process of glass cloth, the sizing agent is degummed by a combination of cleaning and removal treatment based on water and hot water and high-temperature heating treatment for combustion removal. If the water droplet contact angle is below the upper limit value of the above range, it is easy to remove the sizing agent or the combustion residue of the sizing agent by washing with water or hot water. Therefore, there is a tendency to be able to appropriately remove the sizing agent.

[0114] (Width of the glass yarn)

[0115] In the method for manufacturing a glass cloth of the present invention, when manufacturing a glass cloth having a thickness of 26 μm or more and 35 μm or less, glass yarns obtained by bundling 80 or more and 120 or less glass filaments having an average diameter exceeding 4.7 μm and being 5.5 μm or less are used for the warp and weft yarns. The average value of the yarn width measured for 50 m of the glass yarn is preferably 95 μm or more and 125 μm or less. The average value of the yarn width at this time is more preferably 96 μm or more and 123 μm or less, further preferably 97 μm or more and 122 μm or less, and even more preferably in the range of 98 μm or more and 120 μm or less.

[0116] In addition, in the yarn width distribution in the length direction of the glass yarn measured for 50 m, preferably 98.0% or more is composed of a yarn width of 220 μm or less, more preferably 98.0% or more in the length direction is composed of a yarn width of 210 μm or less, further preferably 97.0% or more in the length direction is composed of a yarn width of 200 μm or less, and even more preferably 97.0% or more in the length direction is composed of a yarn width of 190 μm or less.

[0117] By making the average value of the yarn width of the glass yarn be above the above lower limit value, when using the glass yarn for the weft yarn, it can appropriately withstand the ejected air during beating-up, and the weft yarn can be stably blown off with a relatively stable ejection pressure. Therefore, weft breaks and the like do not occur, and good-quality fabric can be stably woven.

[0118] By making the average value of the yarn width of the glass yarn be below the above upper limit value and making 98.0% or more in the yarn width distribution in the length direction of the glass yarn be below the above range, the interference between the glass yarns when unwinding the glass yarn from the glass yarn package or the interference between the glass yarn and loom components such as the yarn path guide during the handling of the glass yarn is suppressed to a small extent. Therefore, even when the sizing agent coating amount is as small as 0.5% by mass or more and 1.2% by mass or less, the occurrence of filament breakage can be suppressed, and a glass cloth with few fluff defects and high quality can be stably obtained.

[0119] In the case of manufacturing a glass cloth having a thickness exceeding 22 μm and less than 26 μm, glass yarns obtained by bundling 80 or more and 120 or less glass filaments having an average diameter exceeding 4.3 μm and being 4.7 μm or less are used for the warp and weft yarns. The average value of the yarn width measured for 50 m of the glass yarn is preferably 80 μm or more and 115 μm or less. The average value of the yarn width at this time is more preferably 82 μm or more and 113 μm or less, further preferably 83 μm or more and 111 μm or less, and even more preferably in the range of 84 μm or more and 110 μm or less.

[0120] In addition, from the viewpoint of the same glass cloth thickness as described above, in the yarn width distribution in the length direction during the measurement of 50 m of the glass yarn, it is preferably composed of 98.0% or more of a yarn width of 190 μm or less, more preferably 98.0% or more in the length direction is composed of a yarn width of 170 μm or less, further preferably 97.0% or more in the length direction is composed of a yarn width of 165 μm or less, and even more preferably 97.0% or more in the length direction is composed of a yarn width of 160 μm or less.

[0121] In the case of manufacturing a glass cloth having a thickness of 10 μm or more and less than 22 μm, a glass yarn obtained by bundling 40 or more and 120 or less or 80 or more and 120 or less glass filaments having an average diameter of 3.5 μm or more and 4.3 μm or less is used for the warp and weft yarns. The average value of the yarn width during the measurement of 50 m of the glass yarn is preferably 70 μm or more and 105 μm or less. The average value of the yarn width at this time is more preferably 72 μm or more and 103 μm or less, further preferably 73 μm or more and 101 μm or less, and even more preferably in the range of 74 μm or more and 100 μm or less.

[0122] In addition, from the viewpoint of the same glass cloth thickness as described above, in the yarn width distribution in the length direction during the measurement of 50 m of the glass yarn, it is preferably composed of 98.0% or more of a yarn width of 170 μm or less, more preferably 98.0% or more in the length direction is composed of a yarn width of 160 μm or less, further preferably 97.0% or more in the length direction is composed of a yarn width of 155 μm or less, and even more preferably 97.0% or more in the length direction is composed of a yarn width of 150 μm or less.

[0123] [Manufacturing process of glass cloth]

[0124] The manufacturing method of the glass cloth according to the present embodiment may include, for example, a weaving process, a fibrillating process, a degumming process, a surface treatment process, etc. Each process will be described below.

[0125] [Weaving process]

[0126] The weaving process is a process of weaving glass yarns to obtain a glass cloth. The weaving method is not particularly limited as long as the weft yarns and warp yarns are woven in a manner to form a specified fabric structure. There is no particular limitation on the fabric structure of the glass cloth, and examples of the fabric structure include a plain weave, a basket weave, a satin weave, a twill weave, etc. Among them, a plain weave structure is more preferably used. The weaving method is not limited to the air-jet loom method, and may also be the water-jet loom method or the shuttle method.

[0127] The beating 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 further preferably 50 to 100 yarns / 25 mm. The beating density of the warp yarn can be controlled by adjusting the interval between the juxtaposed and drawn warp yarns, and the beating density of the weft yarn can be controlled by the number of jets of the weft yarn from the nozzle per unit time and the flow rate of the warp yarn.

[0128] In addition, the thickness of the glass cloth finally obtained through the fibrillating process and the like is 10 μm or more and 35 μm or less. By making the thickness of the glass cloth within the above range, it is possible to realize a thin and high-density mounted printed circuit board for use in a mother board substrate for a smartphone or a semiconductor substrate.

[0129] 〔Fibrillating process〕

[0130] The fibrillating process is a process of fibrillating the glass yarns of the glass cloth. As the fibrillating method, there is no particular limitation, and examples thereof include a method of fibrillating using spray water (high-pressure water fibrillating), a vibro washer, ultrasonic water, a mangle, etc.

[0131] 〔Sizing agent removal process〕

[0132] The sizing agent removal process is a process of removing the sizing agent attached to the glass yarns of the glass cloth. As the sizing agent removal method, there is no particular limitation, and examples thereof include a method of cleaning and removing the sizing agent using water or hot water; a method of heating to remove the sizing agent; a method of combining these methods, etc.

[0133] 〔Surface treatment process〕

[0134] The surface treatment process is a process of performing surface treatment using a silane coupling agent. In addition, as the surface treatment method, examples include a method of bringing a surface treatment agent containing a silane coupling agent into contact with the glass cloth and performing drying, etc. It should be noted that the contact between the surface treatment agent and the glass cloth can include: a method of immersing the glass cloth in the surface treatment agent; a method of coating the glass cloth with the surface treatment agent using a roll coater, a die coater, or a gravure coater, etc. As the drying method of the surface treatment agent, there is no particular limitation, and examples include hot air drying and drying using electromagnetic waves.

[0135] 〔Glass yarn〕

[0136] The glass yarn of the present embodiment is the glass yarn used in the above manufacturing method of the glass cloth. It should be noted that the composition of the glass yarn can be the same as above.

[0137] 〔Glass yarn package〕

[0138] The glass yarn package of the present embodiment is the glass yarn package used in the above-described method for manufacturing glass cloth. It should be noted that the configuration of the glass yarn and its package may be the same as described above.

[0139] 〔Inspection method for distinguishing good and bad of glass yarn package〕

[0140] As another aspect of the present invention, there is provided an inspection method for distinguishing good and bad of a glass yarn package. In the inspection method, based on the physical properties or characteristics of the glass yarn or glass yarn package used in the above-described method for manufacturing glass cloth, and the conditions of each manufacturing process, it is possible to distinguish good and bad of the glass yarn package.

[0141] Examples

[0142] Hereinafter, the present invention will be described more specifically using examples and comparative examples. The present invention is not limited at all to the following examples.

[0143] 〔Physical properties of glass yarn and glass cloth〕

[0144] The physical properties of the glass yarn and glass cloth, specifically the thickness of the glass cloth, the average diameter of the filaments constituting the glass yarn, the TEX of the glass yarn, the beating density (fabric density) of the warp and weft yarns, and the strong heat loss on ignition are measured in accordance with JIS R3420.

[0145] 〔Composition of glass cloth〕

[0146] The composition of the glass cloth is measured by ICP emission spectrometry. After weighing the glass cloth sample and melting it with sodium carbonate, it is dissolved with dilute nitric acid and made up to volume, and the obtained sample is measured by ICP emission spectrometry to determine the Si content and B content. As the ICP emission spectrometry apparatus, PS3520VDD II manufactured by Hitachi High-Technologies Corporation is used.

[0147] 〔Elastic modulus of glass yarn〕

[0148] The elastic modulus of the glass yarn is measured as follows: A glass block obtained by melting and cooling the glass yarn is used as a test piece, and the measurement is performed by the pulse echo overlapping method.

[0149] 〔Sizing agent coating amount of glass yarn〕

[0150] The sizing agent coating amount of the glass yarn is determined as follows by extracting and separating the sizing agent from the glass yarn and performing quantification.

[0151] First, about 3 g of glass yarn is weighed to an accuracy of 0.0001 g to obtain the weight α (g) of the glass yarn. 70 ml of hot water at 80 °C is added to the glass yarn, and while performing ultrasonic treatment and stirring for 15 minutes, the glass yarn and the hot water extract are separated by decantation to obtain hot water extract 1.

[0152] Next, 70 ml of hot water at 80 °C was added to the remaining glass yarn, and ultrasonic treatment was carried out while stirring for 15 minutes. Then, the glass yarn and the hot water extract were separated by decantation to obtain the hot water extract 2.

[0153] Next, 70 ml of acetone was added to the remaining glass yarn, and after stirring for 15 minutes, the glass yarn and the acetone extract were separated by decantation to obtain the acetone extract.

[0154] Furthermore, 70 ml of hexane was added to the remaining glass yarn, and after stirring for 15 minutes, the glass yarn and the hexane extract were separated by decantation to obtain the hexane extract.

[0155] The obtained hot water extract 1, hot water extract 2, acetone extract, and hexane extract were combined. After removing the fragments of the glass yarn mixed therein, they were completely dried. After obtaining the extracted sizing agent in the form of dry matter, the weight β (g) of the extracted sizing agent was weighed to an accuracy of 0.0001 g.

[0156] Based on the weight α (g) of the glass yarn and the weight β (g) of the extracted sizing agent, the sizing agent coating amount of the glass yarn was calculated using the following formula.

[0157] Sizing agent coating amount (%) = {β (g) / α (g)} × 100

[0158] 〔Average yarn width of glass yarn, cumulative frequency ratio when reaching a specified yarn width〕

[0159] While transporting the glass yarn at a speed of 1 m / minute, the yarn width of 50 m of glass yarn was measured using a transmissive type dimension measuring device (HIGHACCURACY CMOS MICROMETER LS-9006MR / manufactured by Keyence Corporation) with the LED projection method. The average value of the yarn width of the glass yarn could be calculated from the obtained yarn width data. In addition, based on the obtained yarn width data, cumulative calculation was carried out starting from the side with the narrower yarn width to calculate the cumulative frequency ratio when the yarn width reached 220 μm, 190 μm, or 170 μm.

[0160] The yarn width measurement using the transmissive type dimension measuring device with the LED projection method was carried out under the condition that 1934 measurement values could be obtained per 1 m. When an error occurred due to the LED focus being out of focus, etc. (a value represented as -9999), the measurement value was deleted, and then the average value of the yarn width and / or the calculation of the yarn width distribution was carried out.

[0161] The tension applied to the glass yarn during handling is the tension value measured using a tensiometer (Conrolinstruments ETPB-100-C0585 manufactured by SCHMIDT), and it is 0.12 to 0.18 N.

[0162] 〔Average surface hardness of the glass yarn package〕

[0163] Using a Type C durometer of DUROMETER (ASKER rubber durometer Type C, manufactured by Polymer Instruments Co., Ltd.), the roll hardness of the glass yarn package is measured as follows.

[0164] Place the glass yarn package horizontally along the transverse direction, and use the above durometer to measure the hardness at the center of the range where the glass yarn is wound. With respect to the circumferential direction of the glass yarn winding, change the position by approximately 90° each time, and conduct 4 measurements. Calculate the average surface hardness in the form of the average value of the 4 obtained hardness values.

[0165] 〔Water droplet penetration time when 2 ml of water droplets are dropped onto the glass yarn package〕

[0166] Measure the time until the water droplets penetrate into the package and disappear when 2 ml of water droplets are dropped onto the glass yarn package as follows.

[0167] Place the glass yarn package horizontally along the transverse direction, drop 2 ml of water droplets onto the center of the range where the glass yarn is wound, and measure the time until the water droplets are impregnated and disappear. With respect to the circumferential direction of the glass yarn winding, change the position by approximately 90° each time, and conduct 4 measurements. Calculate the water droplet penetration time in the form of the average value of the 4 obtained water droplet penetration times.

[0168] 〔Evaluation 1: Evaluation of fly-away property〕

[0169] Using an air-jet loom equipped with a weft storage device of the rotary drum type, conduct the weft insertion test of the glass yarn for the examples, comparative examples, and reference examples, and use the deviation (standard deviation σ) of the weft arrival angle to evaluate the stability of the fly-away property.

[0170] The weft insertion test is carried out under the following conditions: weft insertion speed: 450 picks per minute, weft arrival target angle: set to a specified value, main nozzle pressure: calculate the average value of the weft arrival angles for every 32 picks of the weft, and automatically adjust it so that the obtained average value of the arrival angles becomes the set arrival angle. Insert 2000 picks of the weft, and use the 2000 obtained weft arrival angle values to calculate the standard deviation of the weft arrival angles.

[0171] 〔Evaluation 2: Evaluation of fluff quality based on weaving test〕

[0172] Using an air-jet loom, glass yarns of the examples, comparative examples, and reference examples were used as weft yarns to produce glass cloth, and the fluff quality of the weft yarns in the obtained glass cloth was evaluated.

[0173] The production conditions of the glass cloth are described in each of the examples, comparative examples, and reference examples.

[0174] From the glass cloth where the glass yarns of the examples, comparative examples, and reference examples were inserted as weft yarns, a 0.5 m length was randomly sampled in the length direction. The sampled glass cloth was spread on the experimental bench, and visual inspection was carried out with the naked eye while facing an LED lamp. For the parts considered to be fluff defects, a microscope was used to confirm the presence or absence of filament breakage. When filament breakage of the weft yarn was confirmed, it was regarded as a weft yarn fluff defect, and the quality was evaluated according to the following evaluation criteria.

[0175] 〇: Three or fewer weft yarn fluff defects were confirmed.

[0176] △: Four to nine weft yarn fluff defects were confirmed.

[0177] ×: Ten or more weft yarn fluff defects were confirmed.

[0178] 〔Evaluation 3: Evaluation of the electrical properties (dielectric loss tangent) of the substrate〕

[0179] The glass cloth obtained in the weaving test was impregnated with varnish, and after adjusting the coating amount of the varnish by passing it through a slit, it was dried in a drying oven at 120 °C to obtain a prepreg. The varnish used was a substance containing 65 parts by mass of methacrylated polyphenylene ether, 35 parts by mass of triallyl isocyanurate, 10 parts by mass of hydrogenated styrene-based thermoplastic elastomer, 25 parts by mass of brominated flame retardant, 65 parts by mass of spherical silica, 1 part by mass of organic peroxide, and 210 parts by mass of toluene, and it was adjusted so that the resin content became 73 mass%.

[0180] A predetermined number of the obtained prepregs were overlapped, and copper foils (manufactured by Furukawa Electric Co., Ltd., thickness 18 μm, GTS-MP foil) were further overlapped on both sides of the overlapped prepregs, and vacuum pressing was carried out in this state to obtain a copper-clad laminate. Then, the copper foil was removed from the above copper-clad laminate by etching to obtain a laminate.

[0181] A test piece with a length of about 50 mm and a width of about 1.5 mm was cut out from the obtained laminate with the warp yarns of the glass cloth as the long sides, placed in an oven at 105 °C ± 2 °C, dried for 2 hours, and then left to stand in a constant temperature room at 23 ± 2 °C and a relative humidity of 50 ± 5% for 96 hours, and then the dielectric loss tangent at 10 GHz was measured.

[0182] The measuring device uses a network analyzer (N5230A, manufactured by Agilent Technologies) and a cavity resonator (Cavity Resornator CP series, manufactured by Kanto Electronics Application Development Co., Ltd.) to conduct measurements in an environment of 23 ± 2°C and a relative humidity of 50 ± 5%. Each measurement is performed using 5 test pieces that have been cut out, and the average value thereof is used as the value of the tangent of the dielectric loss angle.

[0183] 〔Test Example〕

[0184] 〔Test Examples 1 to 5, 7 to 8〕

[0185] Low-dielectric glass yarn (TEX: 4.9 g / 1000 m, average diameter of glass filaments: 5.1 μm, number of filaments: 100, elastic modulus: 61 GPa, Si content in the glass composition: 52.9 mass% in terms of SiO 2 conversion, B content in the glass composition: 22.5 mass% in terms of B 2 O 3 conversion) is used for the warp and weft yarns to produce a low-dielectric glass cloth with a thickness of 30 μm.

[0186] In order to investigate the influence of the characteristics of the glass yarn (sizing agent coating amount, strong heat loss, average yarn width, cumulative frequency ratio when the yarn width in the lengthwise distribution of the yarn width becomes 220 μm or less) on the fluff quality of the weft yarn, the test glass yarns shown in Table 1 are used for the weft yarn to conduct tests.

[0187] The fabric is woven using an air-jet loom with a warp fabric density of 65 ends / 25 mm and a weft fabric density of 67 picks / 25 mm. Then, degumming treatment is performed by heating, fibrillating treatment is performed by high-pressure water spraying, and surface treatment is performed using a silane coupling agent to obtain the glass cloth.

[0188] The fluff quality evaluation results of the parts where the test glass yarns are inserted are shown in Table 1.

[0189] In Test Example 5, the sizing agent coating amount becomes 2.0%, and the glass yarn is protected by using a relatively large amount of sizing agent. Therefore, even if there are a large number of parts where the yarn width becomes 220 μm or more, good fluff quality can be obtained.

[0190] On the other hand, in Test Examples 3 and 4, the sizing agent coating amount was 0.7%, which was relatively small. Therefore, if there were a large number of parts where the yarn width was 220 μm or more, good fluff quality could not be obtained. It is speculated that this is because: when the E-glass yarn is unwound from the bobbin, the interference between the yarns becomes stronger due to the wider part of the yarn width. In addition, in the conveying path of the E-glass yarn, the interference between the E-glass yarn and the yarn guide member becomes stronger due to the wider part of the yarn width. As a result, friction occurs at the wider part of the yarn width, and filament breakage occurs.

[0191] In contrast, in Test Examples 1 and 2, the sizing agent coating amount was 0.7%, which was relatively small, but still good fluff quality could be obtained. It is speculated that this is because: the average value of the yarn width was moderately small, and the parts where the yarn width was 220 μm or more were extremely few. Therefore, the interference between the yarns during unwinding from the bobbin and the interference with the yarn guide member in the conveying path were suppressed to a relatively small level. Therefore, even when the sizing agent coating amount was 0.7%, a sufficient protection effect was exhibited.

[0192] In Test Example 7, the ejection of the weft yarn was unstable, and good fluff quality could not be obtained. In Test Example 8, a large amount of fluff was observed in the appearance inspection of the bobbin, and the fluff quality was poor.

[0193] 〔Test Example 6〕

[0194] E-glass yarn (TEX: 5.5 g / 1000 m, average diameter of glass filaments: 5.0 μm, number of filaments: 100, elastic modulus: 74 GPa, Si content in the glass composition: 55.0 mass% in terms of SiO 2 conversion, B content in the glass composition: 7.0 mass% in terms of B 2 O 3 conversion) was used for the warp and weft yarns, and low-dielectric glass cloth with a thickness of 30 μm was produced in the same manner as in Test Examples 1 to 5. The evaluation results of the fluff quality of the parts where the test E-glass yarn was inserted are shown in Table 1.

[0195] In Test Example 6, the elastic modulus was also 74 GPa, which was relatively large. It is speculated that perhaps because the strength of the E-glass yarn was strong, good fluff quality was obtained with a small sizing agent coating amount despite the existence of a large number of parts where the yarn width was 220 μm or more.

[0196] 〔Examples 1 to 6, Comparative Examples 1 to 3, Reference Example 1〕

[0197] <Initial evaluation / Flying property test>

[0198] The flying property of the E-glass yarns in Examples 1 to 6, Comparative Examples 1 to 3, and Reference Example 1 was evaluated.

[0199] The properties of the glass yarns for testing are shown in Table 2 (TEX, average diameter of filaments, number of filaments, Si content in the glass composition, B content, elastic modulus, sizing agent coating amount, weight loss on strong heating, average yarn width, frequency ratio in the length direction of the part where the yarn width is 220 μm or less, average surface hardness of the glass yarn package, water droplet penetration time when 2 ml of water droplets are dropped on the glass yarn package).

[0200] The standard deviation σ of the arrival angles of any of the glass yarns in Examples 1 to 6 is small, indicating good flying properties.

[0201] <10-month storage stability evaluation / flying property test, fluff quality evaluation based on weaving test>

[0202] The glass yarns of Examples 1 to 6, Comparative Examples 1 to 3, and Reference Example 1 were bundled into cardboard boxes and stored for 10 months under the conditions of 22 ± 3°C and a relative humidity of 60 ± 10%.

[0203] After 10 months, the flying property evaluation of the glass yarns and the fluff quality evaluation based on the weaving test were carried out.

[0204] The weaving test was carried out using the following method.

[0205] First, for the warp yarn, a glass yarn with TEX of 5.0 g / 1000 m, an average filament diameter of 5.0 μm, 100 filaments, and a Si content in the glass composition of 52.9 mass% in terms of SiO 2 conversion and a B content of 22.5 mass% in terms of B 2 O 3 conversion was used for warping. Then, the glass yarns of Examples 1 to 6, Comparative Examples 1 to 3, and Reference Example 1 after 10 months of storage were used for the weft yarn, and weaving was carried out using an air-jet loom to obtain a glass cloth fabric. At this time, the fabric density of the warp yarn was set to 65 threads / 25 mm, and the fabric density of the weft yarn was set to 67 threads / 25 mm. Then, degumming treatment was carried out by heating, fibrillating treatment was carried out by high-pressure water spraying, and surface treatment was carried out using a silane coupling agent to produce a glass cloth with a thickness of 30 μm.

[0206] The glass yarns of Examples 1 to 5 also showed a standard deviation equivalent to that of the initial arrival angle in the flying property evaluation after 10 months. In addition, the fluff quality was also good. It can be speculated that since the sizing agent coating amount and the surface characteristics after coating the sizing agent are within the scope of the present application, the moisture absorption of the glass yarn that occurs over time is suppressed, and stable flying properties and fluff quality can be obtained as in the initial stage.

[0207] In the evaluation of the flyability of the glass yarns of Comparative Examples 1 to 3 after 10 months, the standard deviation of the arrival angle increased significantly compared to the initial state. In addition, the fluff quality also deteriorated significantly. It is speculated that for the glass yarns of Comparative Examples 1 and 2, due to the large amount of sizing agent applied, with the passage of time, the moisture absorption of the glass yarns increased, the attenuation of the lubricity of the glass yarns and the increase in viscosity occurred, and thus the flyability and fluff quality changed significantly. It is speculated that for the glass yarn of Comparative Example 3, since the wettability of the glass yarn surface is large and the amount of sizing agent applied is also large, with the passage of time, the moisture absorption of the glass yarns increased, the attenuation of the lubricity of the glass yarns and the increase in viscosity occurred, and thus the flyability and fluff quality changed significantly.

[0208] The glass yarn of Reference Example 1 also showed a standard deviation equivalent to that of the initial arrival angle in the flyability evaluation after 10 months. In addition, the fluff quality was also good. It is speculated that for the glass yarn of Reference Example 1, although the wettability of the glass yarn surface is large, the B content of the glass yarn itself is small and the moisture absorption of the glass itself is small. Therefore, the moisture absorption of the glass yarn does not increase with the passage of time. When using the glass yarn of Reference Example 1 to manufacture a glass cloth, stable flyability and fluff quality can be obtained regardless of the storage period of the glass yarn, but the electrical properties are inferior to those of the glass cloths of Examples 1 to 6 and Comparative Examples 1 to 3.

[0209] 〔Example 7〕

[0210] The properties of the glass yarn are shown in Table 3 (TEX, average diameter of filaments, number of filaments, Si content in the glass composition, B content, elastic modulus, amount of sizing agent applied, weight loss on strong heating, average yarn width, frequency ratio in the length direction of the part where the yarn width is 190 μm or less, average surface hardness of the glass yarn package, water droplet penetration time when 2 ml of water droplets are dropped onto the glass yarn package).

[0211] <Initial evaluation / Flyability test>

[0212] The flyability of the glass yarn was evaluated, and the evaluation results are shown in Table 3. The standard deviation of the arrival angle was small and the flyability was good.

[0213] <10 - month storage stability evaluation / Flyability test, fluff quality evaluation based on weaving test>

[0214] Similar to Example 1, the glass yarn was packed in a cardboard box and stored for 10 months under the conditions of 22 ± 3°C and a relative humidity of 60 ± 10%. After that, the flyability of the glass yarn and the fluff quality evaluation based on the weaving test were carried out.

[0215] The weaving test was carried out using the following method.

[0216] First, for the warp yarn, glass yarn with a TEX of 3.7 g / 1000 m, an average filament diameter of 4.5 μm, 100 filaments, and an Si content in the glass composition of 52.9 mass% in terms of SiO 2 in terms of conversion, and a B content of 22.5 mass% in terms of B 2 O 3 in terms of conversion is used for warping. Next, the glass yarn stored for 10 months is used for the weft yarn, and weaving is performed using an air-jet loom to obtain a glass cloth fabric. At this time, the fabric density of the warp yarn is set to 65 threads / 25 mm, and the fabric density of the weft yarn is set to 67 threads / 25 mm. Then, degumming treatment is carried out by heating, fibrillating treatment is carried out by high-pressure water spraying, and surface treatment is carried out using a silane coupling agent to produce a glass cloth with a thickness of 24 μm.

[0217] In the evaluation of the flyability of the glass yarn in Example 7 after 10 months, it also showed a standard deviation equivalent to that of the initial arrival angle. In addition, the fluff quality was also good.

[0218] 〔Example 8〕

[0219] The characteristics of the glass yarn are shown in Table 3 (TEX, average filament diameter, number of filaments, Si content in the glass composition, B content, elastic modulus, sizing agent coating amount, weight loss on strong heating, average yarn width, frequency ratio in the length direction of the part where the yarn width is 170 μm or less, average surface hardness of the glass yarn package, water droplet penetration time when 2 ml of water droplets are dropped on the glass yarn package).

[0220] <Initial evaluation / Flyability test>

[0221] The flyability of the glass yarn was evaluated, and the evaluation results are shown in Table 3. The standard deviation of the arrival angle was small, and the flyability was good.

[0222] <10-month storage stability evaluation / Flyability test, fluff quality evaluation based on weaving test>

[0223] Similar to Example 1, the glass yarn was packed in a cardboard box and stored for 10 months under the conditions of 22 ± 3°C and a relative humidity of 60 ± 10%. Then, the flyability of the glass yarn and the fluff quality evaluation based on the weaving test were carried out.

[0224] The weaving test was carried out using the following method.

[0225] First, for the warp yarn, glass yarn with a TEX of 2.9 g / 1000 m, an average filament diameter of 4.1 μm, 100 filaments, and an Si content in the glass composition of 52.9 mass% in terms of SiO 2 in terms of conversion, and a B content of 22.5 mass% in terms of B 2 O 3The glass yarn with a conversion of 22.5% by mass was warped. Then, the glass yarn stored for 10 months was used as the weft yarn, and woven using an air-jet loom to obtain a glass cloth fabric. At this time, the fabric density of the warp yarn was set to 65 threads / 25 mm, and the fabric density of the weft yarn was set to 67 threads / 25 mm. Then, degumming treatment was carried out by heating, fibrillating treatment was carried out by high-pressure water spraying, and surface treatment was carried out using a silane coupling agent to produce a glass cloth with a thickness of 21 μm.

[0226] The flyability evaluation of the glass yarn of Example 8 after 10 months also showed a standard deviation equivalent to that of the initial arrival angle. In addition, the fluff quality was also good.

[0227] [Table 1]

[0228]

[0229] [Table 2]

[0230]

[0231] [Table 3]

[0232]

Claims

1. A method for manufacturing a glass cloth, which is a method for manufacturing a glass cloth that uses a glass yarn package for warp and weft yarns and has a thickness of 10 μm or more and 35 μm or less. The glass yarn package is obtained by winding glass yarns with a TEX of 1.0 g / 1000 m or more and 5.6 g / 1000 m or less, an Si content in the glass yarn composition of 40 mass% or more and 60 mass% or less in terms of SiO 2 conversion, and a B content of 15 mass% or more and 30 mass% or less in terms of B 2 O 3 conversion around a bobbin. The sizing agent coating amount of the glass yarn is 0.5% by mass or more and 1.2% by mass or less, and the average surface hardness of the glass yarn package is 68 or more and 86 or less.

2. The method for manufacturing a glass cloth according to claim 1, wherein, the sizing agent coating amount of the glass yarn is 0.6% by mass or more and 1.2% by mass or less.

3. The method for manufacturing a glass cloth according to claim 1, wherein, the sizing agent coating amount of the glass yarn is 0.7% by mass or more and 1.15% by mass or less.

4. The method for manufacturing a glass cloth according to claim 1, wherein, the sizing agent coating amount of the glass yarn is 0.7% by mass or more and 1.1% by mass or less.

5. The method for manufacturing a glass cloth according to claim 1, wherein, when 2 ml of water droplets are dropped onto the glass yarn package, the water droplet penetration time is 20 seconds or more and 300 seconds or less.

6. The method for manufacturing a glass cloth according to claim 5, wherein, the water droplet penetration time is 25 seconds or more and 300 seconds or less.

7. The method for manufacturing a glass cloth according to claim 5, wherein, the water droplet penetration time is 25 seconds or more and 270 seconds or less.

8. The method for manufacturing a glass cloth according to claim 5, wherein, the water droplet penetration time is 25 seconds or more and 250 seconds or less.

9. The method for manufacturing a glass cloth according to claim 1 or 2, wherein, the strong heat heating weight loss of the glass yarn is 0.8% by mass or more and less than 1.5% by mass.

10. The method for manufacturing a glass cloth according to claim 9, wherein, the strong heat heating weight loss of the glass yarn is 0.9% by mass or more and 1.45% by mass or less.

11. The method for manufacturing a glass cloth according to claim 9, wherein, the strong heat heating weight loss of the glass yarn is 1.0% by mass or more and 1.4% by mass or less.

12. The method for manufacturing a glass cloth according to any one of claims 1 to 8, wherein, the glass yarn is a glass yarn obtained by bundling 80 or more and 120 or less glass filaments with an average diameter exceeding 4.7 μm and being 5.5 μm or less. The average value of the yarn width measured at 50 m is 95 μm or more and 125 μm or less. When measured at 50 m, 98.0% or more in the length direction is composed of a yarn width of 220 μm or less.

13. The method for manufacturing a glass cloth according to any one of claims 1 to 8, wherein, the glass yarn is a glass yarn obtained by bundling 80 or more and 120 or less glass filaments with an average diameter exceeding 4.3 μm and being 4.7 μm or less. The average value of the yarn width measured at 50 m is 80 μm or more and 115 μm or less. When measured at 50 m, 98.0% or more in the length direction is composed of a yarn width of 190 μm or less.

14. The method for manufacturing a glass cloth according to any one of claims 1 to 8, wherein, The glass yarn is a glass yarn obtained by bundling 40 or more and 120 or less glass filaments with an average diameter of 3.5 μm or more and 4.3 μm or less. The average value of the yarn width measured at 50 m is 70 μm or more and 105 μm or less. When measured at 50 m, 98.0% or more in the length direction is composed of a yarn width of 170 μm or less.

15. A glass yarn having a TEX of 1.0 g / 1000 m or more and 5.6 g / 1000 m or less, wherein the Si content in the glass yarn composition is 40 mass% or more and 60 mass% or less in terms of SiO 2 conversion, and the B content is 15 mass% or more and 30 mass% or less in terms of B 2 O 3 conversion, is provided. The sizing agent coating amount of the glass yarn is 0.5% by mass or more and 1.2% by mass or less. The glass yarn is in a state of being wound around a bobbin in the form of a glass yarn package, and The average surface hardness of the glass yarn package is 68 or more and 86 or less.

16. The glass yarn according to claim 15, wherein, The sizing agent coating amount of the glass yarn is 0.6% by mass or more and 1.2% by mass or less.

17. The glass yarn according to claim 15, wherein, The sizing agent coating amount of the glass yarn is 0.7% by mass or more and 1.15% by mass or less.

18. The glass yarn according to claim 15, wherein, The sizing agent coating amount of the glass yarn is 0.7% by mass or more and 1.1% by mass or less.

19. The glass yarn according to any one of claims 15 to 18, wherein, When 2 ml of water droplets are dropped onto the glass yarn package, the water droplet penetration time is 20 seconds or more and 300 seconds or less.

20. The glass yarn according to claim 19, wherein, The water droplet penetration time is 25 seconds or more and 300 seconds or less.

21. The glass yarn according to claim 19, wherein, The water droplet penetration time is 25 seconds or more and 270 seconds or less.

22. The glass yarn according to claim 19, wherein, The water droplet penetration time is 25 seconds or more and 250 seconds or less.

23. The glass yarn according to claim 15, wherein, The strong heat heating weight loss of the glass yarn is 0.8% by mass or more and less than 1.5% by mass.

24. The glass yarn according to claim 23, wherein, The strong heat heating weight loss of the glass yarn is 0.9% by mass or more and 1.45% by mass or less.

25. The glass yarn according to claim 23, wherein, The strong heat heating weight loss of the glass yarn is 1.0% by mass or more and 1.4% by mass or less.

26. The glass yarn according to claim 15, wherein, The glass yarn is a glass yarn obtained by bundling 80 or more and 120 or less glass filaments with an average diameter exceeding 4.7 μm and being 5.5 μm or less. The average value of the yarn width measured at 50 m is 95 μm or more and 125 μm or less. When measured at 50 m, 98.0% or more in the length direction is composed of a yarn width of 220 μm or less.

27. The glass yarn according to claim 15, wherein, The glass yarn is a glass yarn obtained by bundling 80 or more and 120 or less glass filaments with an average diameter exceeding 4.3 μm and being 4.7 μm or less. The average value of the yarn width measured at 50 m is 80 μm or more and 115 μm or less. When measured at 50 m, 98.0% or more in the length direction is composed of a yarn width of 190 μm or less.

28. The glass yarn according to claim 15, wherein, the glass yarn is obtained by bundling 40 or more and 120 or less glass filaments with an average diameter of 3.5 μm or more and 4.3 μm or less. The average value of the yarn width measured at 50 m is 70 μm or more and 105 μm or less. When measured at 50 m, 98.0% or more in the length direction is composed of a yarn width of 170 μm or less.

29. The glass yarn according to any one of claims 23 to 28, wherein, when 2 ml of water droplets are dropped onto the glass yarn package, the water droplet penetration time is 20 seconds or more and 300 seconds or less.

30. The glass yarn according to any one of claims 26 to 28, wherein, the strong heat heating weight loss of the glass yarn is 0.8 mass% or more and less than 1.5 mass%.

31. A glass yarn package obtained by winding a glass yarn having a TEX of 1.0 g / 1000 m or more and 5.6 g / 1000 m or less, an Si content in the glass yarn composition of 40 mass% or more and 60 mass% or less in terms of SiO 2 conversion, and a B content of 15 mass% or more and 30 mass% or less in terms of B 2 O 3 conversion around a bobbin. The sizing agent coating amount of the glass yarn is 0.5 mass% or more and 1.2 mass% or less, and the surface average hardness of the glass yarn package is 68 or more and 86 or less.

32. The glass yarn package according to claim 31, wherein, the sizing agent coating amount of the glass yarn is 0.6 mass% or more and 1.2 mass% or less.

33. The glass yarn package according to claim 31, wherein, the sizing agent coating amount of the glass yarn is 0.7 mass% or more and 1.15 mass% or less.

34. The glass yarn package according to claim 31, wherein, the sizing agent coating amount of the glass yarn is 0.7 mass% or more and 1.1 mass% or less.

35. The glass yarn package according to any one of claims 31 to 34, wherein, when 2 ml of water droplets are dropped onto the glass yarn package, the water droplet penetration time is 20 seconds or more and 300 seconds or less.

36. The glass yarn package according to claim 35, wherein, the water droplet penetration time is 25 seconds or more and 300 seconds or less.

37. The glass yarn package according to claim 35, wherein, the water droplet penetration time is 25 seconds or more and 270 seconds or less.

38. The glass yarn package according to claim 35, wherein, the water droplet penetration time is 25 seconds or more and 250 seconds or less.

39. The glass yarn package according to claim 31, wherein, the strong heat heating weight loss of the glass yarn is 0.8 mass% or more and less than 1.5 mass%.

40. The glass yarn package according to claim 39, wherein, the strong heat heating weight loss of the glass yarn is 0.9 mass% or more and 1.45 mass% or less.

41. The glass yarn package according to claim 39, wherein, the strong heat heating weight loss of the glass yarn is 1.0 mass% or more and 1.4 mass% or less.

42. The glass yarn package according to any one of claims 39 to 41, wherein, when 2 ml of water droplets are dropped onto the glass yarn package, the water droplet penetration time is 20 seconds or more and 300 seconds or less.

43. A method for inspecting a glass yarn package, which is a method for inspecting a glass yarn package having a thickness of 10 μm or more and 35 μm or less and used for warp and weft yarns, wherein the glass yarn package is obtained by winding a glass yarn having a TEX of 1.0 g / 1000 m or more and 5.6 g / 1000 m or less, an Si content in the glass yarn composition of 40 mass% or more and 60 mass% or less in terms of SiO 2 and a B content of 15 mass% or more and 30 mass% or less in terms of B 2 O 3 onto a bobbin. The inspection method determines the quality of the glass yarn package based on the sizing agent coating amount of the glass yarn and the surface average hardness of the glass yarn package, wherein, The glass yarn package with the sizing agent coating amount of the glass yarn being 0.5% by mass or more and 1.2% by mass or less and the surface average hardness of the glass yarn package being 68 or more and 86 or less is judged to be good. The glass yarn package with the sizing agent coating amount of the glass yarn outside the range of 0.5% by mass or more and 1.2% by mass or less or the surface average hardness of the glass yarn package outside the range of 68 or more and 86 or less is judged to be bad.

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