Manufacturing method for open-fiber silica glass cloth

Abstract

To provide a manufacturing method of an opened silica glass cloth which can suppress wrinkles or fluffing caused by breakage of silica glass filaments even in a rigid silica glass cloth, allows warp yarns to be sufficiently opened, and can have uniform smoothness and good resin-impregnating properties.SOLUTION: There is provided a manufacturing method of an opened silica glass cloth, which comprises an opening treatment step of: winding a silica glass cloth 200 having an ignition loss of 0.1% or more as measured by a method described in JIS R 3420:2013 into a roll; spraying a water-based liquid W1 while conveying the roll in a state where a spray irradiation angle (θ1) of a spray header M formed by connecting a plurality of spray nozzles m in the crosswise direction with respect to a plane of the silica glass cloth on a support member is 5 to 175° and the direction in which a spray width sprayed from the spray nozzles becomes maximum is biased by 1° or more to the crosswise direction of the silica glass cloth; and winding the silica glass cloth in a roll shape.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for producing an opened silica glass cloth. [Background technology]

[0002] With the advancement of high-speed communications such as 5G, there is a strong demand for high-speed communication boards and antenna boards that have low transmission loss even when using high frequencies such as millimeter waves.In addition, there has been a remarkable trend towards high-density packaging and ultra-thinning of wiring boards in information terminals such as smartphones.

[0003] To lower the dielectric loss tangent of organic resin substrates, such as printed wiring boards for high-speed communications like 5G, inorganic powders or glass cloth, which have lower dielectric loss tangents than resins, are commonly used. For example, laminates are widely used in which low-dielectric glass cloths, such as D-glass, NE-glass, and L-glass, are impregnated with thermoplastic resins such as fluororesins and polyphenylene ethers, or thermosetting resins such as low-dielectric epoxy resins and low-dielectric maleimide resins, and then laminated and cured under heat and pressure. While glass cloths with improved dielectric properties, such as D-glass, NE-glass, and L-glass, have been proposed, the dielectric loss tangents of all of these glasses are high (approximately 0.002–0.005) in the high-frequency range above 10 GHz. This results in significant transmission loss and inaccurate transmission of information when using high-frequency waves, such as millimeter waves, for communications. Furthermore, it is known that signal transmission loss is improved with materials having lower dielectric constants (ε) and dielectric loss tangents (tanδ), as shown by the Edward A. Wolff equation: transmission loss ∝√ε × tanδ.

[0004] As an even lower dielectric glass cloth, silica glass cloth is generally known to have very good dielectric properties, and Patent Document 1 states that its dielectric loss tangent is 0.0020 or less at 10 GHz. Its use in future high-speed communication substrates and antenna substrates such as 5G will enable reduction in transmission loss.

[0005] On the other hand, it is known that glass cloth, which is mainly used as a laminate for printed wiring boards, is subjected to a fiber-opening treatment in order to improve the resin impregnation property and surface smoothness of the glass cloth.

[0006] As a method for this opening treatment, a method using ultrasonic waves has been disclosed. Patent Documents 2 and 3 specifically describe opening treatment of glass cloth by ultrasonic treatment.

[0007] Patent Document 4 describes a method in which a high-pressure water jet is sprayed onto a glass cloth to open glass filaments with high concentration. This conventional method uses a small diameter of about 0.1 to 0.2 mm and a pressure of 4.9 to 14.7 MPa (50 to 150 kg / cm). 2 ) is sprayed onto the glass cloth in a high-pressure columnar water jet, which separates and opens the glass filaments at the joints, allowing them to be impregnated with resin well.

[0008] With the recent trend toward smaller electronic devices, there is an increasing demand for thinner laminates. To achieve this, a glass cloth with a small mass and a small thickness is used. Furthermore, it is preferable that the glass fiber yarns in such a glass cloth be widened, the glass fibers be uniformly distributed in the laminate, and the glass cloth be smoothed. Furthermore, as printed wiring boards become denser and thinner, CAF (Conductive Anodic Filament: copper migration) in printed wiring boards becomes a problem. Therefore, it is necessary to improve CAF resistance by further enhancing resin impregnation. In these respects, further improvements in the above-mentioned fiber-spreading technology are desired.

[0009] The above is also required for silica glass cloth with good dielectric tangent, and ultra-thin silica glass cloth that has been subjected to fiber opening treatment is most suitable for organic resin substrates such as printed wiring boards for high-speed communications such as 5G.

[0010] However, when continuous ultrasonic treatment is used to open a long fiber woven fabric such as glass cloth, ultrasonic waves are generally applied through the medium while the glass cloth is running through the medium. Therefore, the opening process is performed under conditions where tension acts in the running direction (warp direction) and almost no tension acts in the width direction (weft direction). Therefore, the method of immersing a long fiber woven fabric such as glass cloth in a medium has the problem that wrinkles are likely to occur due to distortion caused by the weft threads shrinking in the width direction.

[0011] With the fiber-opening method using ultrasound, it is currently difficult to achieve uniform fiber-opening processing for reasons such as the fact that ultrasound is a compressional wave and the strength of the pressure acting on it varies depending on the location in the medium, and that the propagation of ultrasound is hindered in areas where bubbles generated from dissolved air in the medium are present.

[0012] The ultrasonic fiber-opening method has the problem that it is difficult to adjust the degree of opening to match the resin to be impregnated, and there is also the problem that thin cloth is prone to bending and filament breakage. If bending occurs, it may lead to uneven resin impregnation and reduced insulation reliability.

[0013] In the glass cloth spreading method using a high-pressure columnar water jet described in Patent Document 4, the high-pressure columnar water jet is blown onto the glass cloth, which causes problems such as roughening of the weave of the glass cloth and damage to some of the glass filaments, resulting in increased generation of fluff. This fluffing is likely to cause irregularities on the surface of the prepreg, and in printed wiring boards, this can damage the copper foil layered on the prepreg, potentially resulting in circuit defects. These problems are particularly pronounced in the case of rigid silica glass cloth. Furthermore, this method requires high jetting pressure and requires drying to remove moisture after treatment, resulting in high energy and equipment costs, and there is also the risk of the glass filaments re-adhering to each other during drying.

[0014] Furthermore, Patent Document 5 describes a method of spreading fibers by spraying a diffusion spray into the atmosphere. This spreading method by spraying water has almost no spreading effect on the warp yarns, so the warp yarns are not sufficiently spread, and it is considered preferable to adjust the positions of adjacent diffusion sprays in the width direction so that they overlap, which poses a problem that a uniform spreading effect cannot be obtained in the width direction of the glass cloth.

[0015] The problems associated with the above-mentioned fiber-spreading method are more pronounced with rigid silica glass cloth, and further methods are desired for preventing wrinkles, twisting, and fluffing due to filament breakage in the above-mentioned conventional fiber-spreading method for silica glass cloth.

[0016] Furthermore, as in conventional fiber-opening processes, the tension applied to the warp yarns during the process causes the warp yarns to bunch up, making it difficult to open them.Furthermore, there is a problem that the warp yarns are not sufficiently opened, making it impossible to sufficiently thin the silica glass cloth. [Prior art documents] [Patent documents]

[0017] [Patent Document 1] Patent Publication No. 2021-063320 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-241515 [Patent Document 3] Japanese Patent Application Laid-Open No. 2014-070325 [Patent Document 4] Japanese Patent Application Laid-Open No. 1996-127959 [Patent Document 5] Japanese Patent Application Laid-Open No. 2003-171864 Summary of the Invention [Problem to be solved by the invention]

[0018] The present invention has been made in view of the above problems, and aims to provide a method for producing an opened silica glass cloth which is rigid and suppresses wrinkles and fluffing due to broken silica glass filaments, and which also allows sufficient opening of warp yarns, and which has uniform smoothness and excellent resin impregnation properties. [Means for solving the problem]

[0019] As a result of intensive research into achieving the above object, the present inventors have found that it is possible to provide a method for producing spread silica glass cloth, which involves spreading silica glass cloth while winding and transporting the silica glass cloth in the form of a roll, by setting the ignition loss of the silica glass cloth and the spray irradiation angle from the spray header to the plane of the silica glass cloth on a support member within specific ranges, and further by deflecting the direction in which the spray width from the spray nozzle is maximum within a specific range with respect to the width direction of the silica glass cloth, so that the rigid silica glass cloth can suppress wrinkles and fluffing due to breakage of silica glass filaments, has a high warp occupancy rate, can fully spread the warp, has a small standard deviation of air permeability, is excellent in uniform smoothness, has low air permeability, has high warp and weft occupancy rates, and is excellent in resin impregnation, thereby solving the above problems and leading to the present invention.

[0020] Therefore, the present invention provides a method for producing an opened silica glass cloth. 1. A method for producing an opened silica glass cloth, comprising weaving warp and weft yarns made of glass filaments having an SiO2 composition of 96.0 to 100.0 mass %, and opening the resulting silica glass cloth, A silica glass cloth having an ignition loss of 0.1% or more as measured by the method described in JIS R 3420:2013 was wound into a roll and transported. From a spray header with multiple spray nozzles connected in the width direction, The spray irradiation angle (θ1) relative to the surface of the silica glass cloth on the support member is 5 to 175°. the water-based liquid W1 is sprayed in a state where the direction in which the spray width is maximum when sprayed from the spray nozzle is deflected by 1° or more with respect to the width direction of the silica glass cloth; The method includes a fiber-opening process in which the silica glass cloth is wound into a roll. Manufacturing method for open-fiber silica glass cloth. 2. The method for producing an open-fiber silica glass cloth according to 1, wherein the spray distribution sprayed from the spray nozzle is fan-shaped or full cone-shaped, and the spray angle (θ2) at which the spray diameter sprayed from the spray nozzle is maximum is 15° or more. 3. The method for producing an opened-fiber silica glass cloth according to 2, wherein the spray angle (θ2) is 15 to 175°. 4. The method for producing spread fiber silica glass cloth according to any one of 1 to 3, wherein the spray headers are arranged in two or more rows, and the distance between the spray headers in the conveying direction of the silica glass cloth is 5 mm or more. 5. The method for producing a spread-fiber silica glass cloth according to any one of 1 to 4, wherein the average spray particle size of the water-based liquid W1 is 10 to 500 μm. 6. The method for producing a spread-fiber silica glass cloth according to any one of 1 to 5, wherein the temperature of the water-based liquid W1 sprayed from the spray nozzle is 20 to 90°C. 7. The method for producing spread fiber silica glass cloth according to any one of 1 to 6, wherein the transport speed of the silica glass cloth is 0.2 m / min or more. 8. The method for producing spread fiber silica glass cloth according to any one of 1 to 7, wherein the thickness of the silica glass cloth is 100 μm or less. 9. The mass per unit area of the silica glass cloth is 4 to 100 g / m 2 9. The method for producing a spread silica glass cloth according to any one of 1 to 8, wherein 10. The method for producing an open-fiber silica glass cloth according to any one of 1 to 9, wherein the silica glass cloth is subjected to a tassel treatment in the width direction of the fabric. 11. The method for producing an opened silica glass cloth according to any one of 1 to 10, further comprising a pressing step of pressing the opened silica glass cloth in the thickness direction after the opening step. 12. A method for producing an opened silica glass cloth according to any one of 1 to 11, further comprising a step of blowing compressed air or heating and drying the opened silica glass cloth after the opening treatment step or the opened silica glass cloth after the pressing treatment step. [Effects of the Invention]

[0021] According to the present invention, a manufacturing method can be provided for producing an opened silica glass cloth which is rigid, suppresses wrinkles and fluffing due to broken silica glass filaments, and allows sufficient opening of warp yarns, has good smoothness, and is particularly excellent in resin impregnation. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a diagram showing an overview of a method for manufacturing opened silica glass cloth according to an embodiment of the present invention; [Figure 2] FIG. 2 is a side view of the schematic overview of the method for producing opened silica glass cloth shown in FIG. 1. [Figure 3] 2 is a view of the spray header M of the opened silica glass cloth manufacturing method shown in FIG. 1, viewed from the spray nozzle mounting surface. [Figure 4] FIG. 10 is a diagram showing the flow rate distribution (spray cross section) of the spray flow along the diffusion direction for different types of spray nozzle m, and droplets W2 that break up into droplets due to the diffusion. [Figure 5] FIG. 10 is a diagram showing the flow rate distribution at the diameter at which the spray distribution width is maximum for the type of spray nozzle m. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, an embodiment of the method for producing an opened silica glass cloth according to the present invention will be described in detail with reference to the drawings, but the present invention is not limited to this. In addition, the same or corresponding parts in all the drawings will be designated by the same reference numerals.

[0024] [Silica glass cloth] The silica glass cloth 200 to be subjected to the fiber-opening treatment is a silica glass cloth formed by weaving warp and weft yarns made of glass filaments having an SiO2 composition of 96.0 to 100.0 mass %. The silica glass cloth is obtained by weaving glass fiber bundles made of a plurality of silica glass filaments, and is formed by weaving warp and weft yarns, for example.

[0025] The SiO2 composition amount is 96.0 to 100.0 mass%, preferably 98.0 to 100.0 mass%. The diameter of the glass filaments is preferably 3.0 to 9.0 μm. The weave density of the warp and weft of the silica glass cloth is preferably 40 to 120 threads / 25 mm.

[0026] To perform the opening treatment step effectively, the thickness of the silica glass cloth 200 is preferably 100 μm or less, more preferably 5 to 100 μm, and even more preferably 5 to 70 μm. With such a silica glass loss, the opening treatment effect is significantly exhibited, and it is possible to meet the demand for lighter, thinner, shorter, and smaller printed wiring boards used in the electronic and electrical fields these days. A thickness of 5 μm or more is preferable because it has high rigidity and is less likely to bend or wrinkle.

[0027] In this embodiment, the width of the silica glass cloth 200 is 1,270 mm, but this width is not particularly limited. The mass per unit area is 4 to 100 g / m 2 is preferable, and 4 to 50 g / m 2 It is more preferable that the silica glass cloth is subjected to selvedge treatment in the width direction of the fabric. Such a silica glass loss can prevent fraying of the width direction end of the silica glass cloth when the above-mentioned fiber-opening treatment step is carried out.

[0028] The ignition loss of the silica glass cloth is 0.1% or more, preferably 0.1 to 5.0% by mass, and more preferably 0.2 to 4.0% by mass. The ignition loss is a value measured by the method described in JIS R 3420:2013. By setting the ignition loss to 0.1% or more for a rigid silica glass cloth, the silica glass filaments are protected, and the spray opening process is then carried out under an adjusted spray pressure. Therefore, for a rigid silica glass cloth that has not been able to sufficiently suppress fluffing and wrinkling using conventional techniques, it is now possible to perform fiber opening while conveying the cloth in the longitudinal direction while suppressing fluffing and wrinkling.

[0029] The method for producing the silica glass filaments that make up the silica glass cloth 200 is not particularly limited, but an example is a method in which 230 μm quartz threads drawn from a quartz ingot in an electric furnace are spun using an oxyhydrogen burner. The thickness of the silica glass filaments is preferably in the range of 3 to 25 μm. The silica glass filament strand is produced by bundling multiple glass filaments with a sizing agent. This sizing agent is, for example, a starch-based or PVA (polyvinyl alcohol)-based sizing agent containing a film-forming agent component.

[0030] The count of the silica glass filaments is preferably in the range of 0.5 to 20 tex. The count (tex) of the glass fiber bundle corresponds to the mass (grams) of the glass fiber per 1,000 m. The weave of the silica glass cloth 200 may be plain weave or twill weave, with plain weave being preferred.

[0031] As described above, it is preferable that the ignition loss of the silica glass cloth 200 is 0.1% or more and that 0.1% or more of organic matter is attached to the silica glass cloth. Examples of organic matter include sizing agents used to improve convergence during spinning of silica glass filaments, to protect the silica glass yarn during weaving, and to improve its flight characteristics, and silane coupling agents used to improve affinity with resins after weaving the silica glass cloth. Among these, it is preferable that the attached organic matter in the opening treatment of the silica glass cloth 200 is a sizing agent. If the attached organic matter is a sizing agent, the opening treatment softens the sizing agent by applying spray vibrations in an aqueous liquid, making the opening of the fiber bundles more likely to occur. On the other hand, after the deoiling process in which the sizing agent is heat-treated in a heating furnace or the like to remove the sizing agent, the sizing agent in the silica glass cloth solidifies due to heat, a so-called heat-setting phenomenon occurs, which may result in insufficient opening. Therefore, it is more preferable to perform the opening treatment before the deoiling process.

[0032] In the embodiment, when the organic matter attached to the silica glass cloth 200 is the sizing agent, the opening treatment step is carried out before the silica glass cloth raw material is subjected to the deoiling treatment. On the other hand, a suitable example of another organic matter in the silica glass cloth opening method of the present invention is a silane coupling agent. That is, the silica glass cloth 200 may be subjected to the deoiling treatment, and then further subjected to the silane treatment at an adhesion rate of 0.1% or more, followed by the opening treatment step. The silane coupling agent used in the silane treatment is a silane compound having a hydrolyzable group and a hydrophobic group (organic group). Examples of such compounds include silane coupling agents having an unsaturated double bond, such as vinyltriethoxysilane, vinyltrimethoxysilane, and γ-(methacryloyloxypropyl)trimethoxysilane; silane coupling agents having an epoxy group, such as β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidyloxypropyltrimethoxysilane, and γ-glycidyloxypropylmethyldiethoxysilane; silane coupling agents having a mercapto group, such as γ-mercaptopropyltrimethoxysilane; and silane coupling agents having an amino group, such as γ-aminopropyltriethoxysilane, N-β(aminoethyl)γ-aminopropyltrimethoxysilane, and N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane.

[0033] [Opening process] The fiber-opening process is performed by the fiber-opening device S1. The fiber-opening process includes a spray header M (spraying device) consisting of multiple spray nozzles m in the width direction that supply and spray an aqueous liquid W1 (e.g., water), a support member 100, and rotors 11-14. As a result, while the silica glass cloth 200 wound in a roll is transported, the spraying device consisting of multiple spray nozzles m in the width direction sprays the aqueous liquid W1 onto the surface of the silica glass cloth 200 transported over the support member 100, causing the silica glass cloth 200 to break into droplets, and the opening process is performed in that state, and the silica glass cloth 200 is wound into a roll by a roller 15. The tension in the warp direction on the silica glass cloth 200 can be adjusted as appropriate, but it is sufficient to use a normal tension required for transportation. Therefore, the method of transporting the silica glass cloth in this embodiment is not limited as long as it is possible to unwind and rewind the silica glass wound in a roll and it is possible to provide a fiber-opening device S1.

[0034] The spray header M is preferably designed so that each spray nozzle m can be arranged in a straight line parallel to the width direction of the silica glass cloth. The spray header M is designed so that the spray irradiation angle θ1 formed by the conveying direction V1 of the silica glass cloth and the spray direction V2 of the nozzle center of each attached spray nozzle m can be appropriately adjusted to a range of 5 to 175° while maintaining parallelism with the width direction of the silica glass cloth 200 being conveyed. θ1 is preferably 45 to 85°, or 95 to 135°.

[0035] In the fiber-opening process of the present invention, the spray irradiation angle (θ1) is adjusted relative to the plane of the silica glass cloth, and the direction in which the nozzle spray width is maximized is not parallel to the width direction of the silica glass cloth. The direction in which the spray width from the spray nozzle is maximized is deflected by 1° or more relative to the width direction of the silica glass cloth, and the directions in which the spray width from adjacent spray nozzles is maximized do not directly overlap. As a result, when the conveying direction of the silica glass cloth is the warp direction and the width direction is the weft direction, the vector of the spray force from the spray nozzle propagates not only in the weft direction but also in the warp direction. This reduces the force that the weft undulation exerts on the warp, resulting in sufficient warp opening. Furthermore, by performing the fiber-opening process by spraying an aqueous liquid, the binding force of the surface treatment agent and binder attached to the glass single fibers is relaxed, resulting in good warp opening.

[0036] Typically, adjacent spray nozzles are installed so that the angle between the direction in which the spray distribution width of each nozzle is greatest and the weft direction of the silica glass cloth is 1° or less, and the sprays in the direction in which the spray distribution width is greatest directly overlap with adjacent sprays connected to the same header. In this case, collisions and overlaps between adjacent sprays inevitably impair the uniformity of the spray impact (strike force) in the nozzle connection direction, preventing sufficiently uniform fiber-spreading. Furthermore, because the direction in which the spray distribution width is greatest is perpendicular to the warp direction, sufficiently uniform fiber-spreading of the warp yarns is also impossible. On the other hand, in the fiber-spreading process of this manufacturing method, the spray distribution is angled relative to the weft direction to prevent overlap in the width direction in which the spray distribution of adjacent spray nozzles is greatest. Meanwhile, the difference in flow rate between the end and center of the spray area of each spray nozzle is considered in the conveying direction of the silica glass cloth as shown in Figure 1. The distance between adjacent spray nozzles is adjusted so that the final flow rate of the spray received at each position in the width direction of the silica glass cloth is approximately equal at every position. Furthermore, by spraying while conveying, the impact of the spray collision acts to make the hitting force uniform at all points in the width direction of the silica glass cloth, thereby achieving a uniform fiber-opening process in the width direction.

[0037] In the fiber-opening treatment step of the present invention, the spray headers may be arranged in two or more rows at intervals of 5 mm or more in the conveying direction as the number of spray stages in the conveying direction of the silica glass cloth. In this case, by increasing the number of stages of spray headers, it is possible to increase the conveying speed of the silica glass cloth.

[0038] When the number of spray stages in the conveying direction is increased as described above, it is more preferable to install the spray nozzles of the next spray header to be connected so that they do not overlap with the spray nozzles attached to the previous spray header in the width direction of the silica glass cloth. This makes the spray action under the above conditions more effective and allows for a uniform fiber-opening process.

[0039] For example, in two or more rows of spray headers, the positions of the spray nozzles in each row may be shifted by 5 mm or more in the width direction of the silica glass cloth being transported. By installing and spraying adjacent spray headers of spray headers M that are connected in the width direction with a shift of 5 mm or more, more uniform spraying can be achieved in the width direction of the silica glass cloth 200. As shown in Figure 3, it is more preferable that the spray nozzle m of the connected spray header M is located in the center of the spray nozzles m connected to adjacent spray headers M.

[0040] Furthermore, the spray distribution of the spray from the spray nozzle m is preferably fan-shaped or full cone-shaped, and at least in the spray distribution, the spray angle (θ2) in the direction of maximum diameter is preferably 15° or more, more preferably 15 to 175°, and even more preferably 50 to 150°. The difference in spray distribution depending on the type of spray nozzle is shown in Figure 4. There are other types of spray nozzles that are classified according to the spray distribution, such as hollow cone nozzles. In all of these types of spray nozzles, adjusting the spray angle (θ2) can reduce the number of nozzles attached to one row of a nozzle header to ensure that the spray distribution covers the entire width of the silica glass cloth, thereby reducing energy and water costs.

[0041] The flow rate distribution at this time may be a mountain-shaped distribution in which the flow rate at the periphery is smaller than the flow rate at the center, or an even distribution in which the difference in flow rate between the periphery and the center is small except at the ends. All of these different types of spray nozzles classified according to the difference in flow rate between the center of the flow rate distribution and its periphery can be used in this embodiment.

[0042] Each spray nozzle m can be fixed to the spray header M and rotated around a fixed axis, allowing for free adjustment of the angle of the direction in which the spray distribution of the spray nozzle reaches its maximum diameter relative to the cloth conveying direction. As shown in Figures 1 and 3, the spray nozzles m are arranged along the width direction of the silica glass cloth. The spacing (pitch) between the spray nozzles m attached to one spray header M and the angle θ3 of the diameter direction in which the spray width of each spray nozzle m reaches its maximum relative to the silica glass cloth conveying direction are adjusted so that the spray streams from adjacent spray nozzles m do not substantially overlap and impinge as sprays on the surface of the silica glass cloth 200 on the support member 100. That is, a design is used in which the direction in which the spray width of the spray from each spray nozzle m reaches its maximum is deflected by 1° or more relative to the cloth width direction, with a deviation of 3 to 30° being preferred, 4 to 20° being more preferred, and 5 to 20° being even more preferred. The process by which the spray stream breaks into droplets will be described in detail in the section below on the action of the spray stream in opening the silica glass cloth 200.

[0043] The support member 100 is installed on the opposite side of the surface on which the spray header M of the silica glass cloth 200 is attached. With the spray surface facing upward, it serves to support the silica glass cloth 200 as it is sprayed from above and to transmit the energy generated by the droplets W2 sprayed from the spray nozzle m colliding on the support member to the silica glass cloth 200, thereby further enhancing the opening effect. Because the support member 100 is pressed against the support member during transport due to the impact of the droplets W2 from the spray header M on the support member, it is preferable to select a material with minimal irregularities or a non-lattice-like shape to ensure smooth transport. Examples of suitable materials include a plate with fine pores, such as aluminum porous material, which allows liquid to pass through, or a plate made of fluororesin. The support member 100 is installed above the post-spray treatment liquid tank 101.

[0044] The type of the aqueous liquid W1 used in the spray nozzle m for spreading the silica glass cloth 200 is not particularly limited as long as it contains water, and it is preferable that water be the main component (the component with the largest amount). For example, tap water or industrial water may be used as the water. Furthermore, the sizing agent attached to the glass fiber bundle may be dissolved in the water, and particles such as colloidal silica may be contained.

[0045] The colloidal silica-containing aqueous liquid is a colloidal solution of fine particles made of ultrahigh molecular weight silicic anhydride. More specifically, the volume-average particle diameter of these fine particles is preferably 5 to 500 μm, more preferably 70 to 100 μm. The volume-average particle diameter can be measured using a laser diffraction particle size distribution analyzer, and can be calculated as the mass average value D50 (i.e., the particle diameter or median diameter at which the cumulative mass is 50%) in particle size distribution measurement using a laser diffraction method.

[0046] The content of colloidal silica in the colloidal silica-containing aqueous liquid is preferably 0.01 to 5 mass %, more preferably 0.1 to 2 mass %. When the silica glass cloth 200 is immersed in the colloidal silica-containing aqueous liquid to perform the fiber-opening treatment, the colloidal silica particles penetrate sufficiently between the glass filaments, and these particles secure gaps between the silica glass filaments, thereby obtaining a silica glass cloth with even better resin impregnation properties.

[0047] The average spray particle diameter of the aqueous liquid W1 is preferably 10 to 500 μm. By setting it within this range, a scattered hitting force is applied to the glass cloth, resulting in fiber spreading. The average spray particle diameter is more preferably 50 to 400 μm, and even more preferably 50 to 300 μm. By setting the average particle diameter to 50 μm or more, the droplets are given appropriate energy against the rigid silica glass filament bundle, thereby improving the hitting force when colliding with the glass cloth, while also mitigating the impact caused by the droplets colliding with the glass fiber bundle, further suppressing misalignment and fluffing, resulting in more efficient fiber spreading. The average spray particle diameter is measured using a laser Doppler method to calculate the Sauter mean particle diameter (SMD) (hereinafter referred to as "droplet diameter").

[0048] The water temperature of the aqueous liquid W1 is preferably 20 to 90° C., more preferably 40 to 70° C. By setting the water temperature of the aqueous liquid W1 within the above range, the softening of the sizing agent attached to the glass fiber bundles is promoted, and the opening effect of the opening device S1 in the silica glass cloth 200 can be improved. If the water temperature is less than 20° C., the softening of the sizing agent is likely to be insufficient, and even if the water temperature is higher than 90° C., the softening of the sizing agent is not promoted.

[0049] Furthermore, the moving speed when the silica glass cloth 200 is conveyed by the rollers 11 to 15 during the opening treatment process and the spraying time during the spraying of the aqueous liquid W1 are not particularly limited, and can be appropriately changed depending on the thickness of the silica glass cloth 200 and the count of the glass fiber bundle. When increasing the moving speed, it is preferable to increase the number of nozzle spray stages to maintain a constant spray amount per unit area. From the viewpoint of productivity, the conveying speed is preferably 0.2 m / min or more, more preferably 0.2 to 100 m / min, and even more preferably 2.0 to 100 m / min.

[0050] In addition to the spray opening treatment of the present invention, the silica glass cloth 200 can be subjected to other opening treatments to flatten the fibers that make up the silica glass cloth 200. Examples of other opening treatments include opening by water flow pressure, opening by high-frequency vibration using a liquid as a medium, processing by the pressure of a fluid with surface pressure, and processing by pressing with a roll. Among these opening treatment methods, processing by the pressure of a fluid with surface pressure and processing by pressing with a roll are more preferred because they can align the uniformity and fiber direction of the fibers and prevent misalignment. Furthermore, in order to enhance the effect of the flattening treatment, it is preferable to carry out the other opening treatments described above while reducing the tension applied to the glass cloth for transportation.

[0051] Next, the action of the spray stream sprayed from the spray nozzle m to open the silica glass cloth 200 will be explained. Figure 4 is a diagram showing the diffusion of the spray stream sprayed from the spray nozzle m. Figure 4 shows a cross section of the spray distribution at the position where the spray diameter from the spray nozzle m is maximum. The high-pressure liquid sprayed into the atmosphere from the nozzle of the spray nozzle m diffuses in a direction determined by the type of the spray nozzle m to form a spray stream. The spray stream sprayed from the spray nozzle m diffuses in a linear shape that spreads downward. The linearly diffused spray stream is split into upper and lower parts due to the vibration and diffusion of the spray angle, and further becomes multiple droplets W2 due to the surface tension of the liquid.

[0052] These effects cause droplets W2 to collide with each other, exerting scattered pressure on the surfaces of the warp and weft yarns (silica glass strands) made of multiple silica filaments, which allows the silica glass strands to be efficiently opened.

[0053] The size of the droplets W2 can be appropriately set by adjusting factors such as the type of spray nozzle m, the spray pressure, and the distance between the spray nozzle m and the support member 100. The type of spray nozzle m here refers to differences in spray flow rate, spray angle range, and spray distribution depending on the size of the spray nozzle m when the same spray pressure is applied. From the viewpoint of not applying excessive pressure to the silica glass filaments and achieving a balance between fiber-spreading and preventing misalignment and fluffing of the silica glass strands, the droplet diameter of the droplets W2 is preferably 10 to 500 μm, more preferably 50 to 400 μm, and even more preferably 50 to 300 μm.

[0054] The spray pressure is preferably adjusted within the range of 0.1 to 1.0 MPa so as to satisfy the above average spray particle diameter, and each nozzle m used in the treatment step is preferably selected to have a shape that can achieve this condition.

[0055] Fig. 4 is a diagram showing the diffusion pattern of the spray stream as viewed along the spray direction. Fig. 5 is a diagram showing the flow rate distribution of the spray stream along the diffusion direction of the spray nozzle, which diffuses in a fan-shaped distribution. As shown in Fig. 5, the flow rate of the spray stream is high at the center and decreases from the center to both ends. In the silica glass cloth spreading method of this embodiment, multiple spray nozzles m are arranged along the width direction of the silica glass cloth being transported, and the ends of the spray streams sprayed from each spray nozzle m are set at an angle θ3 with respect to the axis of the spray nozzle, so that the ends of the spray streams sprayed from adjacent spray nozzles m hardly overlap each other directly. Meanwhile, as the silica glass cloth is transported, the flow rate received in the width direction is ultimately equal at any position, and it is possible to uniformly distribute the hitting force in the width direction of the silica glass cloth, thereby achieving a uniform spreading process without unevenness in the width direction.

[0056] In this embodiment, by setting the spray irradiation angle θ1 in the range of 5 to 175° with respect to the plane of the glass cloth, it is possible to set a spray angle not only in the vertical direction, and by setting the above-mentioned oscillation angle θ3 to the spray nozzle m that sprays, the vector of the spray's hitting force from the spray nozzle propagates not only in the width direction of the silica glass cloth but also in the conveying direction, so that the opening action of the spray described above also works in the warp direction, and the force that the waviness of the weft yarns exerts on the warp yarns is reduced, resulting in sufficient opening of the warp yarns. It is preferable to spray θ1 in the range of 45 to 85° or 95 to 135° and the oscillation angle θ3 in the range of 5 to 20° from the viewpoints of water cost and sufficient opening effect of the warp and weft yarns.

[0057] Since the support member 100 supports the silica glass cloth 200, the impact of the droplets W2 colliding with the silica glass cloth 200 is increased, making it easier to open the fibers. In addition, the portion of the silica glass strand opposite the side hit by the spray stream, i.e., the portion in contact with the surface of the support member 100, is also pressed against the surface of the support member 100, opening the silica glass strand. The spray stream may also be sprayed onto both sides of the silica glass cloth to open it. There are various types of spray nozzles, such as those that spray only liquid, those that spray a mixture of liquid and gas, and those that spray a water stream that has been ultrasonically vibrated. However, there are no particular restrictions on the spray nozzle that can be used in the present invention, as long as the desired droplet diameter can be achieved.

[0058] At this time, the silica glass filaments are protected in advance by an organic substance, and the measured loss on ignition is 0.1% or more. This gives flexibility to the rigid silica glass strand, and the filaments are in a state where they can move easily without becoming frayed by the blowing force of the spray. As a result, the filaments separate and open simultaneously with the impact of the blowing force of the droplets.

[0059] Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and various modifications can be made. For example, the arrangement of the spray header M is not limited to the above embodiments. Specifically, the conveying direction of the silica glass cloth 200 may be vertical rather than horizontal to save space in the spreading device, or may be configured to convey along a direction at a predetermined angle to the horizontal. However, considering the uniformity and quality of the spreading of the silica glass cloth 200, it is preferable that the sprayed aqueous liquid does not pass through to the end of the conveying direction of the silica glass cloth 200 (the winding side), but rather flows down. Furthermore, a mechanism for repeating spreading by spraying and drying may be used as a process for connecting multiple spreading processes. Furthermore, the method for conveying the silica glass cloth 200 wound into a roll is not limited, and the diameter, number, and position of the rollers can be appropriately changed depending on the thickness, weight, and other physical properties of the silica glass cloth 200.

[0060] [Pressing process] The method for producing an opened silica glass cloth of the present invention preferably further comprises a pressing step of pressing the opened silica glass cloth in the thickness direction after the opening treatment. By pressing the silica glass cloth 200 in the thickness direction, it is possible to prevent misalignment while further opening the weft yarns.

[0061] [Air blowing with compressed air or heat drying process] The method for producing an open-fiber silica glass cloth of the present invention preferably further comprises a step of drying the open-fiber silica glass cloth by air blowing with compressed air or by a heat drying step, and then winding up the dried and open-fiber treated silica glass cloth. For example, a mechanism for passing the open-fiber treated silica glass cloth through a hot air drying oven at 120°C for 10 minutes after the open-fiber treatment step can be mentioned. By providing such a post-treatment step, it is possible to prevent the glass cloth after the open-fiber treatment step from meandering during winding and the layers of the cloth from sticking together after winding.

[0062] [Open-fiber silica glass cloth] The "open-fiber silica glass cloth" obtained by the manufacturing method of the present invention preferably has the following evaluation values. The evaluation methods are those used in the Examples. The thickness (μm) is preferably 5 to 100 μm, more preferably 5 to 70 μm. The warp occupancy (%) can be 55 to 90%, preferably 70 to 90%. The weft occupancy (%) can be 70 to 100%, preferably 80 to 100%. Air permeability (cm 3 / cm 2 / sec) is 5 to 80 (cm 3 / cm 2 / sec), and the speed can be set to 5 to 50 (cm 3 / cm 2 / sec) is preferable. The standard deviation of the air permeability is 1 to 12 cm 3 / cm 2 / sec is preferred, 1 to 8cm 3 / cm 2 / sec is more preferable. The suitable ranges of the air permeability, warp occupancy rate, and weft occupancy rate are appropriately selected depending on the thickness and weaving density of the glass cloth. [Example]

[0063] EXAMPLES The present invention will be specifically explained below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[0064] [Silica glass cloth manufacturing example] SQ11: The quartz fiber is stretched at high temperature while being coated with a sizing agent for silica glass fiber, and the quartz fiber is then stretched to a diameter of 5.3 μm with an SiO2 content of 99.9 μm. mass A silica glass strand consisting of 200 silica glass filaments was prepared. The resulting silica glass strand was then twisted 0.4 times per 25 mm to prepare a silica glass yarn.

[0065] The obtained silica glass yarn was set in an air jet loom to weave a plain weave silica glass cloth (SQ11) with a warp density of 54 / 25 mm and a weft density of 54 / 25 mm. SQ11 had tassel selvage treatment, a thickness of 63 μm, and a cloth mass of 49.7 g / m. 2The organic matter adhesion rate of SQ11 was 2.3% when measured for loss on ignition. The ignition loss measurement conditions were based on JIS R 3420:2013, and were 625°C for 2 hours.

[0066] SQ12: Comparison product The SQ11 fabricated above, measuring 1,270 mm in width and 2,000 m in length, was placed in an electric furnace set at 400°C and heated for 72 hours to deoil. After heating, it was cooled to room temperature over 24 hours. This silica glass cloth was designated SQ12. The SQ12 had a thickness of 62 μm and a cloth mass of 48.6 g / m. 2 The organic matter adhesion rate measured by ignition loss was 0.0%.

[0067] Next, the SQ12 fabricated above, measuring 1,270 mm in width and 2,000 m in length, was surface-treated with a silane coupling agent KBM-903 (product name: 3-aminopropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.) in the following process and wound into a roll. This silica glass cloth was named SQ13. The thickness of SQ13 was 63 μm, and the cloth mass was 48.7 g / m. 2 The organic matter adhesion rate measured by ignition loss was 0.2%.

[0068] [Example 1] The 1,270 mm-wide SQ11 was subjected to a fiber-spreading process using the fiber-spreading device S1 (see FIG. 1) described in the embodiment. Specifically, in the fiber-spreading process, as shown in FIG. 1, tap water at 25°C was used as the aqueous liquid W1, and nine VVP-115-19 spray nozzles m (manufactured by Ikeuchi Co., Ltd., spray pattern: fan-shaped, spray angle θ2 = 115°) were arranged at 150 mm intervals in the width direction to form a spray header M1. The spray headers M1 were arranged in four tiers at 50 mm intervals, the spray pressure was 0.5 MPa, and the average spray particle size was 250 μm. The swing angle θ3 of each nozzle was set to 5° to prevent sprays from adjacent nozzles from directly overlapping each other, and the spray width in the same direction as the width of the SQ11 was adjusted to 1,320 mm. The nozzle height from SQ11, which is the direction perpendicular to the width, was 100 mm, and the spray angle θ1 was 110°. The support member 100 was made of a SUS304 plate with countless fine holes of 100 μm in size.

[0069] In addition, the conveying speed of the silica glass cloth 200 by rollers 11 to 15 was 5 m / min, and the tension in the warp yarn direction, which is the silica glass cloth conveying direction, was 20 N / m.After the fiber-opening process, a drying process was performed using air blowing, and then the silica glass cloth was obtained by winding it up by roller 15.

[0070] [Example 2] A silica glass cloth was obtained by carrying out the opening treatment in the same manner as in Example 1, except that the silica glass cloth used was a silica glass cloth that had been subjected to a deoiling process and a silane treatment, namely SQ13.

[0071] [Example 3] The opening treatment was carried out in the same manner as in Example 1, except that the spray irradiation angle θ1 of the spray header was set to 5°, to obtain a silica glass cloth.

[0072] [Example 4] The opening treatment was carried out in the same manner as in Example 1, except that the spray irradiation angle θ1 of the spray header was set to 45°, to obtain a silica glass cloth.

[0073] [Example 5] The opening treatment was carried out in the same manner as in Example 1 except that the spray irradiation angle θ1 of the spray header was set to 80°, to obtain a silica glass cloth.

[0074] [Example 6] The opening treatment was carried out in the same manner as in Example 1 except that the spray irradiation angle θ1 of the spray header was set to 85°, to obtain a silica glass cloth.

[0075] [Example 7] The opening treatment was carried out in the same manner as in Example 1 except that the spray irradiation angle θ1 of the spray header was set to 90°, to obtain a silica glass cloth.

[0076] [Example 8] The opening treatment was carried out in the same manner as in Example 1 except that the spray irradiation angle θ1 of the spray header was set to 95°, to obtain a silica glass cloth.

[0077] [Example 9] The opening treatment was carried out in the same manner as in Example 1 except that the spray irradiation angle θ1 of the spray header was set to 135°, to obtain a silica glass cloth.

[0078] [Example 10] The opening treatment was carried out in the same manner as in Example 1 except that the spray irradiation angle θ1 of the spray header was set to 175°, to obtain a silica glass cloth.

[0079] [Example 11] The opening treatment was carried out in the same manner as in Example 1 except that the swing angle θ3 of each nozzle was set to 1°, to obtain a silica glass cloth.

[0080] [Example 12] The opening treatment was carried out in the same manner as in Example 1 except that the swing angle θ3 of each nozzle was set to 15°, to obtain a silica glass cloth.

[0081] [Example 13] The opening treatment was carried out in the same manner as in Example 1 except that the swing angle θ3 of each nozzle was set to 20°, to obtain a silica glass cloth.

[0082] [Example 14] The fiber-opening treatment was carried out in the same manner as in Example 1, except that a nozzle with an average spray particle size of 50 μm was used, to obtain a silica glass cloth.

[0083] [Example 15] The fiber-opening treatment was carried out in the same manner as in Example 1, except that a nozzle with an average spray particle size of 300 μm was used, to obtain a silica glass cloth.

[0084] [Example 16] The fiber-opening treatment was carried out in the same manner as in Example 1, except that a nozzle with an average spray particle size of 400 μm was used, to obtain a silica glass cloth.

[0085] [Example 17] The opening treatment was carried out in the same manner as in Example 1, except that the temperature of the aqueous liquid W1 was set to 60°C, to obtain a silica glass cloth.

[0086] [Example 18] A fiber-opening treatment was carried out in the same manner as in Example 1, except that a spray nozzle m was used that had a spray pressure of 0.5 MPa, an average spray particle size of 250 μm, and a spray pattern that formed a full cone as shown in Figure 4, to obtain a silica glass cloth.

[0087] [Example 19] A silica glass cloth was obtained by carrying out the same fiber-opening treatment as in Example 1, except that a colloidal silica-containing aqueous liquid was used instead of tap water as the aqueous liquid W1. The colloidal silica used had a particle size of 70 μm and a concentration of 0.2 mass% relative to the colloidal silica-containing aqueous liquid.

[0088] [Comparative Example 1] After the deoiling process in Example 1, the silica glass cloth according to Comparative Example 1 was obtained by carrying out the fiber-opening process in the same manner as in Example 1, except that a silica glass cloth with an ignition loss of 0% that had not been silane-treated, i.e., SQ12, was used.

[0089] Comparative Example 2 The opening treatment was carried out in the same manner as in Example 1 except that the spray irradiation angle θ1 of the spray header was set to 3°, to obtain a silica glass cloth.

[0090] Comparative Example 3 The opening treatment was carried out in the same manner as in Example 1 except that the spray irradiation angle θ1 of the spray header was set to 180°, to obtain a silica glass cloth.

[0091] Comparative Example 4 In Example 1, the opening process was carried out in the same manner as in Example 1, except that the swing angle θ3 of the spray nozzle m was set to 0° and the distance between adjacent nozzles was set to 80 mm so that the sprays overlapped with each other, thereby obtaining a silica glass cloth.

[0092] Comparative Example 5 In Comparative Example 2, a silica glass cloth was obtained by carrying out the same fiber-opening treatment as in Example 1, except that the spray irradiation angle θ1 of the spray header was set to 90°, the swing angle θ3 of the spray nozzle m was set to 0°, and the distance between adjacent nozzles was set to 80 mm so that the sprays overlapped each other.

[0093] Comparative Example 6 A fiber-opening treatment was carried out in the same manner as in Example 1, except that a fiber-opening treatment step using an ultrasonic treatment tank was provided instead of the fiber-opening treatment step, and a silica glass cloth according to Comparative Example 6 was obtained. Specifically, an ultrasonic generator vibrator was placed inside a single-tank treatment tank, and aqueous liquid W2 was stored therein. The silica glass cloth was transported inside the treatment tank using rollers, so that the silica glass cloth was immersed in the aqueous liquid W2 and subjected to ultrasonic treatment, thereby obtaining a silica glass cloth. The size of one side of the vibrator was 200 mm, the output frequency was 100 kHz, and the ultrasonic power density was 1.2 kW.

[0094] Comparative Example 7 A silica glass cloth was obtained by carrying out the fiber-opening treatment in the same manner as in Example 1, except that a high-pressure water jet was used instead of the fiber-opening treatment step. Conventionally known techniques can be used for the high-pressure water jet treatment step, and in this comparative example, a method was used in which a plurality of nozzles with a diameter of 0.1 to 0.2 mm were arranged in the width direction of the running woven fabric, and the nozzles were moved at high speed to spray very thin columnar streams.

[0095] (Evaluation method and results) Samples measuring 1,270 mm wide x 50 mm long were taken from the silica glass cloths of the examples and comparative examples, and 20 samples were taken at equal intervals in the width direction, and 3 rows were taken in the length direction, for a total of 60 samples. The thickness (μm), warp occupancy (%), weft occupancy (%), and air permeability (cm 3 / cm 2 / sec) was measured. Measurements were made at 60 locations in each of the examples and comparative examples, and the average value was calculated for each value. In addition, the standard deviation for the air permeability was also calculated.

[0096] The warp occupancy rate and the weft occupancy rate were calculated as follows based on the numerical values of the glass fibers constituting the glass cloth. Warp occupancy rate = A1 / A x 100 (%) Weft occupancy rate = B1 / B x 100 (%) A: Warp spacing, A1: Warp width, B: Weft spacing, B1: Weft width The appearance of the silica glass cloth was also observed under a microscope to check for defects that could become drawbacks. Those without defects were rated as ◯. The treatment conditions and evaluation results of the opened silica glass cloths of the examples and comparative examples are shown in the table below.

[0097] In the example, the air permeability of the silica glass cloth is 38.5 cm 3 / cm 2 / sec or less, and the weft occupancy rate is also high at 83% or more. The warp occupancy rate is also high at 70% or more, which shows that the warp yarns are also sufficiently opened. The standard deviation of the air permeability is 6.1cm 3 / cm 2 / sec or less, and it has uniform smoothness. By subjecting silica glass cloth to the method for manufacturing spread silica glass cloth of the present invention, spread silica glass cloth was obtained that was well packed and had excellent uniform resin impregnation, compared to comparative examples in which the spreading conditions were outside the scope of the present invention. Furthermore, when the glass cloth was observed under a microscope, no misalignment or fluffing was found in the examples.

[0098] On the other hand, the opened silica glass cloths (Comparative Examples 1 to 6) outside the scope of the present invention were unable to achieve both an excellent opening effect with high uniformity in the width direction and glass cloth quality without defects such as misalignment and fluff that would cause substrate defects.

[0099] As shown in Table 1, from the results of Examples 1 and 2, it was confirmed that a greater opening effect was achieved when this opening treatment step was performed on a raw silica glass cloth roll to which a sizing agent had been attached before the deoiling step.

[0100] In this way, by using the method for manufacturing an open-fiber silica glass cloth of the present invention, it is possible to suppress misalignment and fluffing in a rigid silica glass cloth, and also to sufficiently open the weft and warp yarns, thereby producing an open-fiber silica glass cloth that has good smoothness and is particularly excellent in resin impregnation.

[0101] Furthermore, by using the open-fiber silica glass cloth of the present invention and performing a deoiling process using heat treatment and surface treatments such as silane treatment, the dielectric tangent is low, making it suitable for use in high-speed communication substrates and antenna substrates with low transmission loss even when using high frequencies such as millimeter waves.It can also be used to achieve high-density packaging and ultra-thinning of wiring boards, making it highly useful in the field of high-speed communications such as 5G.

[0102] The present invention is not limited to the above-described embodiments. The above-described embodiments are merely examples, and anything that has substantially the same configuration as the technical idea described in the claims of the present invention and that exhibits similar effects is included within the technical scope of the present invention.

[0103] [Table 1]

[0104] [Table 2]

[0105] [Table 3]

[0106] [Table 4] [Explanation of symbols]

[0107] W1 Water-based liquid W2 droplet 11~15 Laura S1 Fiber opening processing equipment M spray header m Spray nozzle 100 Support member 101 Post-spray treatment liquid tank 200 Silica glass cloth

Claims

1. SiO 2 A method for producing an opened silica glass cloth, comprising weaving warp yarns and weft yarns made of glass filaments having a composition amount of 96.0 to 100.0 mass % to form a silica glass cloth, and opening the resulting cloth, A silica glass cloth having an ignition loss of 0.1% or more as measured by the method described in JIS R 3420:2013 is wound into a roll and transported. From a spray header with multiple spray nozzles connected in the width direction, The spray irradiation angle (θ1) relative to the surface of the silica glass cloth on the support member is 5 to 175°. the direction in which the spray width from the spray nozzle is maximized is deflected by 1° or more with respect to the width direction of the silica glass cloth, and the aqueous liquid W1 is sprayed in such a state that the sprays from adjacent spray nozzles do not directly overlap each other; The method includes a fiber-opening process in which the silica glass cloth is wound into a roll. Manufacturing method for open-fiber silica glass cloth.

2. 2. The method for producing an open-fiber silica glass cloth according to claim 1, wherein the spray distribution from the spray nozzle is fan-shaped or full cone-shaped, and the spray angle (θ2) at which the spray diameter from the spray nozzle is maximum is 15° or more.

3. 3. The method for producing spread fiber silica glass cloth according to claim 2, wherein the spray angle (θ2) is 15 to 175°.

4. 4. The method for producing spread fiber silica glass cloth according to claim 1, wherein the spray headers are arranged in two or more rows, and the distance between the spray headers in the conveying direction of the silica glass cloth is 5 mm or more.

5. 5. The method for producing an opened-fiber silica glass cloth according to claim 1, wherein the average atomized particle size of the aqueous liquid W1 is 10 to 500 μm.

6. The method for producing spread fiber silica glass cloth according to any one of claims 1 to 5, wherein the temperature of the water-based liquid W1 sprayed from the spray nozzle is 20 to 90°C.

7. 7. The method for producing an opened silica glass cloth according to claim 1, wherein the conveying speed of the silica glass cloth is 0.2 m / min or more.

8. The method for producing an opened silica glass cloth according to any one of claims 1 to 7, wherein the thickness of the silica glass cloth is 100 µm or less.

9. The mass per unit area of the silica glass cloth is 4 to 100 g / m 2 The method for producing the opened silica glass cloth according to any one of claims 1 to 8, wherein

10. The method for producing an open-fiber silica glass cloth according to any one of claims 1 to 9, wherein the silica glass cloth is subjected to a tufted selvedge treatment in the width direction of the fabric.

11. The method for producing an opened silica glass cloth according to any one of claims 1 to 10, further comprising a pressing step of pressing the opened silica glass cloth in the thickness direction after the opening step.

12. The method for producing an opened silica glass cloth according to any one of claims 1 to 11, further comprising a step of blowing compressed air or heating and drying the opened silica glass cloth after the opening treatment step or the opened silica glass cloth after the pressing treatment step.

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