KR20230159386A - glass cloth - Google Patents

Abstract

The object of the present invention is that the residual curvature 2HB/B, which is the ratio of the bending hysteresis 2hb in the weft direction to the bending stress B in the weft direction, is 0.5 (cm ^-1 ) or less and the shear stress in the weft direction G (gf/cm/deg) To provide a glass cloth having a shear hysteresis ratio of 2HG (gf/cm) in the weft direction and a residual shear deflection rate 2HG/G of 1.4 (deg ^-1 ) or less. A glass cloth composed of warp and weft yarns made of a plurality of long glass fibers, and comprising (A) polyoxyalkylene bisphenol A ether, and (B) an acrylic group or methacryl group on at least a portion of the surface of the glass long fibers. A glass cloth containing a silane coupling agent, wherein the warp density and weft density of the glass cloth are 70 pieces/25 mm or more, and the carbon content of the glass cloth is 0.4 to 1.5% by mass.

Description

glass cloth

The present invention relates to glass cloth and prepreg.

A laminated board such as a printed wiring board includes an insulating layer and a conductor layer formed thereon. As an insulating layer, glass fiber reinforced resin reinforced with a glass fiber base material such as glass cloth is commonly used.

Recently, the demand for miniaturization and high performance of electronic components has become significant, and further miniaturization is also required for laminated boards. In order to meet these demands, thin printed wiring boards and multilayer printed wiring boards are being developed, and thin glass cloth is being developed as the glass fiber used for these.

For example, in Patent Document 1, even if the average number of stages is less than 3.00, the occurrence of pinholes can be suppressed in a prepreg using glass cloth, and the excellent appearance quality of the prepreg can be maintained because the glass cloth has little fluff. It describes a glass cloth that can be maintained. Specifically, in Patent Document 1, the composition of the glass cloth is composed of warp and weft yarns in which 14 to 55 glass long fibers with a diameter in the range of 3.0 to 4.2 μm are concentrated, and the warp and weft yarns are The weave density is in the range of 86 to 140 pieces/25mm, the thickness is in the range of 7.5 to 12.0㎛, and the weave density is in the range of 6.0 per ^1m2 . It has a mass in the range of ~ 10.0 g, and the thickness of the glass cloth is divided by the average value of the diameter of the warp glass long fibers and the diameter of the weft glass long fibers (thickness of the glass cloth / {(of the warp glass long fibers A glass cloth with an average number of stages expressed as diameter + diameter of the glass long fiber of the weft)/2}) in the range of 2.00 to 3.00, wherein the openness of the warp yarn (the actual width of the warp yarn / (of the glass long fiber constituting the warp yarn) is in the range of 2.00 to less than 3.00. The geometric mean (diameter The average openness expressed as (openness of the warp × fineness of the weft) is in the range of 1.000 to 1.300, and the ratio of the yarn width of the warp to the yarn width of the weft (yarn width of the warp / yarn width of the weft) A glass cloth having a real width ratio expressed in the range of 0.720 to 0.960 is described.

On the other hand, the glass cloth is surface treated with a silane coupling agent in order to increase the impregnation and adhesion of the prepreg and the matrix resin in the printed wiring board obtained from the prepreg to the glass cloth. The surface-treated glass cloth includes a glass fiber fabric and a treatment agent attached to the glass fiber fabric, wherein the treatment agent is a surface-treated glass fiber fabric containing a silane compound and a water-soluble polyurethane. It is known (for example, see Patent Document 2). According to the surface-treated glass fiber fabric, it is said that it is possible to provide a surface-treated glass fiber fabric that has sufficient rigidity and a surface-treated glass fiber fabric that has sufficient rigidity even when the thickness is reduced.

Patent Document 1: Japanese Patent Publication No. 2018-21274 Patent Document 2: Japanese Patent Publication No. 2006-342445

In recent years, in order to meet the demand for miniaturization of electronic devices and the demand for high-performance printed wiring boards for high functionality, prepregs and printed wiring boards are becoming thinner. In order to reduce the thickness of prepreg and printed wiring boards, thin glass cloth is required. In addition, for reasons such as the rapidly increasing demand for transmitting and processing large amounts of data at high speeds, low dielectric constant is required for glass fibers used in prepregs and printed wiring boards.

In order to form a thin glass cloth, it is necessary to weave using warp and weft yarns made of glass fibers with smaller fiber diameters, and flatten the warp and weft yarns through an opening treatment.

In order to reduce the dielectric constant of glass fiber, low dielectric constant glass (for example, NE glass, L glass, Unity Chemical Company brand name LU glass, etc.) is used as a glass material constituting the glass fiber.

Glass cloth using thin glass cloth or low-dielectric constant glass has a problem of low tensile strength and easy breakage compared to glass cloth using relatively thick and general-purpose E glass.

Here, the glass cloth used for prepreg and printed wiring boards is surface treated with a surface treatment agent containing a silane coupling agent. The surface treatment process is carried out in the final process of glass cloth. Surface treatment is performed by impregnating a glass cloth continuous in the diagonal direction with a surface treatment agent containing a silane coupling agent, adjusting the adhesion amount of the surface treatment agent using a nip roll, and drying it. The dried glass cloth is wound to form a glass cloth roll, and the glass cloth roll is rewound and impregnated with a matrix resin to form a prepreg.

And, as studied by the present inventors, when manufacturing a glass cloth with a relatively low tensile strength, such as a thin glass cloth or a glass cloth using low dielectric constant glass, using the techniques of Patent Documents 1 and 2, the glass cloth In order to prevent breakage, etc., if the warp direction tension applied to the glass cloth in the final surface treatment process is set to be relatively low, vertical stripes (stripes extending in the longitudinal direction of the warp of the glass cloth) will be formed on the wound glass cloth. I realized that there is a problem that is more likely to occur. Specifically, by lowering the tension in the warp direction, a bend or wave shape occurs in the weft direction (width direction) of the glass cloth during the surface treatment process, and when it passes through the nip roll with the bend or wave shape formed, the glass cloth bends in the width direction. It was discovered that they overlap, causing vertical stripes to form. If vertical stripes occur in the surface treatment process, which is the final process, the vertical stripes may be carried into the prepreg manufacturing process as is, and may affect the quality of the prepreg.

In addition, as studied by the present inventors, when manufacturing glass cloth with relatively low tensile strength, such as thin glass cloth or glass cloth using low dielectric constant glass, using the techniques of Patent Documents 1 and 2, when winding Partially skewed (a state in which the weft yarn is not perpendicular to the warp yarn) occurs in the glass cloth, and stress is concentrated in the skewed part, causing diagonal wrinkles (non-parallel to the longitudinal direction of the warp yarn) during winding. It was found that there are cases where wrinkles (wrinkles extending in a direction that is parallel to the length direction of the weft thread) occur. This phenomenon does not normally occur, for example, in the case of relatively thick glass cloth using E glass material. And, if diagonal wrinkles occur during winding in the surface treatment process, which is the final process, there is a risk that the diagonal wrinkles will be carried into the prepreg manufacturing process as is and affect the quality of the prepreg.

After further investigation by the present inventors, in order to suppress the above-mentioned vertical stripes, the "bending hysteresis 2hb in the weft direction with respect to the bending stress in the weft direction is determined by using a pure bending tester, which is a type of feel measuring instrument, under the conditions described below. It was learned that it is important to keep the residual curvature 2HB/B" below 0.5 (cm ^-1 ). The residual curvature 2HB/B is calculated from the bending hysteresis (2HB) and bending rigidity (B) obtained from the hysteresis curve in bending characteristics measured with a pure bending tester, and is calculated from the energy loss in the recovery deformation process from bending deformation. This is determined by the amount of residual bending, and the restoring force is quantified as a value of 2HB/B. In other words, the residual curvature 2HB/B can be understood as residual bending in the recovery deformation process from bending deformation, and the smaller this residual bending is, the higher the restoring force is. The present inventors set the residual curvature 2HB/B to 0.5 (cm ^-1 ) or less to make it difficult for bending or wavy shapes to occur during the glass cloth manufacturing process, and to prevent vertical stripes from occurring when passing the nip roll during the process. I found that it was easy to do.

In addition, as studied by the present inventors, in order to suppress the above-mentioned diagonal wrinkles, the "shear stress G (gf/cm/deg) in the weft direction" is determined by using a tensile shear tester, which is a type of feel measuring instrument, under the conditions described later. It was found that it is important to keep the residual shear deflection rate 2HG/G", which is the ratio of the shear hysteresis 2HG (gf/cm) in the weft direction, to 1.4 (deg ^-1 ) or less. The residual shear deflection rate 2HG/G is calculated from the shear hysteresis 2HG and the shear stress G obtained from the hysteresis curve in the shear characteristics measured with a tensile shear tester, and the energy loss in the recovery deformation process from shear deformation is calculated as the residual deflection amount. By understanding this, the resilience is quantified as a value of 2HG/G. In other words, this value can be understood as residual bending in the recovery deformation process from shear deformation, and the smaller the residual bending, the higher the restoring force. The present inventors found that by setting the residual shear bending rate to 1.4 (deg ^-1 ) or less, the bending inherent in the glass cloth is likely to be alleviated during passage of the cloth in the surface treatment process, making it easier to prevent the occurrence of diagonal wrinkles during winding. did.

Therefore, the present invention solves the above problem, and the residual curvature 2HB/B, which is the ratio of the bending hysteresis 2hb in the weft direction to the bending stress B in the weft direction, is 0.5 (cm ^-1 ) or less and the shear stress in the weft direction G (gf The main task is to provide a glass cloth with a residual shear deflection rate 2HG/G, which is the ratio of the shear hysteresis 2HG (gf/cm) in the weft direction to /cm/deg), of 1.4 (deg ^-1 ) or less. In addition, another object of the present invention is to provide a glass cloth in which the occurrence of vertical stripes and diagonal wrinkles is suppressed.

The present inventors studied the above problem. In order to reduce the residual curvature 2HB/B, it is necessary to increase the bending rigidity B while reducing the bending hysteresis 2HB in the weft direction. In order to reduce the bending hysteresis 2HB in the weft direction of the glass cloth, in the surface treatment process, a surface containing (A) polyoxyalkylene bisphenol A ether, and (B) a silane coupling agent having an acrylic group or methacryl group is used. We have learned that it is important to apply a treatment agent to the glass cloth. In addition, it was found that in order to increase the bending rigidity B, it is effective to increase the amount of adhesion of the surface treatment agent.

Additionally, in order to reduce the residual shear deflection rate in the weft direction, it is necessary to increase the shear stress G in the weft direction while reducing the shear hysteresis 2HG in the weft direction. In order to reduce the shear hysteresis 2HG in the weft direction of the glass cloth, in the surface treatment process, a surface treatment agent containing (A) polyoxyalkylene bisphenol A ether, and (B) a silane coupling agent having an acrylic group or methacryl group. I realized that it is important to give the glass cloth. In addition, in order to increase the shear stress G in the weft direction, it was found that it is important to set the warp density and weft density of the glass cloth above a certain value and increase the friction force due to the movement of the interwoven points accompanying shear deformation.

In addition, the present inventors, in a glass cloth composed of warp and weft yarns made of a plurality of glass long fibers, (A) polyoxyalkylene bisphenol A ether, and (B) on at least part of the surface of the glass long fibers. By containing a silane coupling agent having an acrylic group or a methacryl group, setting the warp density and weft density of the glass cloth to 70 pieces/25 mm or more, and setting the carbon content of the glass cloth to 0.4 to 1.5 mass%, the residual curvature It was found that when 2HB/B is 0.5 (cm ^-1 ) or less and the residual shear bending rate 2HG/G is 1.4 (deg ^-1 ) or less, the occurrence of vertical stripes and diagonal wrinkles can be suppressed.

The present invention is an invention that was completed through repeated careful studies based on such knowledge.

That is, the present invention provides the invention of the aspects listed below.

Clause 1. A glass cloth composed of warp and weft yarns made of a plurality of glass long fibers,

At least a portion of the surface of the glass long fiber includes (A) polyoxyalkylene bisphenol A ether, and (B) a silane coupling agent having an acrylic group or methacryl group,

The warp density and weft density of the glass cloth are 70 pieces/25mm or more,

A glass cloth wherein the carbon content of the glass cloth is 0.4 to 1.5 mass%.

Item 2. The glass cloth according to Item 1, wherein the tensile strength in the warp direction is 20 to 120 N/25 mm.

Item 3. The glass cloth according to item 1 or 2, having a thickness of 5 to 30 μm.

Item 4. The glass cloth according to any one of items 1 to 3, which is a roll-shaped long glass cloth formed by winding a glass cloth around a core.

Item 5. A prepreg comprising the glass cloth according to any one of items 1 to 4, and a thermosetting resin impregnated in the glass cloth.

According to the glass cloth of the present invention, the weaving density and carbon content of the glass cloth are set to a specific range by performing surface treatment with a specific surface treatment agent, so that the residual curvature 2HB/B is 0.5 (cm ^-1 ) or less and the residual shear bending rate 2HG is achieved. /G can satisfy 1.4 (deg ^-1 ) or less, and the occurrence of vertical stripes and diagonal wrinkles can be effectively suppressed.

Figure 1(a) shows a schematic diagram when measuring the residual curvature 2HB/B using a pure bending tester, and (b) shows an example of a bending hysteresis curve obtained using a pure bending tester.
Figure 2(a) shows a schematic diagram when measuring the residual shear deflection rate 2HG/G using a tensile shear tester, and (b) shows an example of a shear hysteresis curve obtained using a tensile shear tester.

1. Glass cloth

The glass cloth of the present invention is a glass cloth composed of warp and weft yarns made of a plurality of glass long fibers, and (A) polyoxyalkylene bisphenol A ether and (B) on at least a portion of the surface of the glass long fibers. ) A silane coupling agent having an acrylic group or a methacryl group is included, the weaving density of the glass cloth is 70 pieces/25 mm or more, and the carbon content of the glass cloth is 0.4 to 1.5% by mass. Below, the glass cloth of the present invention will be described in detail.

[Glass yarn that makes up glass cloth]

In the glass cloth of the present invention, glass yarn made of a plurality of long glass fibers is used as the warp and weft yarns.

In the glass cloth of the present invention, the glass material constituting the long glass fiber is not particularly limited. For example, E glass, T glass, S glass, UT glass, D glass, NE glass, L glass, Unity Chemical Company brand name LU glass, C glass, or AR glass.

From the viewpoint of versatility, it is preferable to use glass yarn with an E glass composition. The E glass composition includes SIO ₂ in the range of 52 to 56% by mass, B ₂ O ₃ in the range of 5 to 10% by mass, and Al ₂ O in the range of 12 to 16% by mass, based on the total amount of glass fibers. ₃ , CaO and MgO in a total range of 20 to 25% by mass, and Li ₂ O, K ₂ O and Na ₂ O in a total range of 0 to 1% by mass.

In addition, from the viewpoint of further increasing the strength of the prepreg and printed wiring board, the glass yarn contains SiO ₂ in the range of 60 to 66% by mass and Al ₂ O ₃ in the range of 20 to 26% by mass relative to the total amount of glass fibers. It is preferably made of a glass material having a composition containing MgO in the range of 10 to 15 mass%.

Furthermore, from the viewpoint of reducing the dielectric constant and dielectric loss tangent of prepreg and printed wiring boards, the glass yarns include SiO ₂ in the range of 45 to 60% by mass and B in the range of 15 to 35% by mass based on the total amount of glass fibers. It is preferably made of a glass material containing ₂ O ₃ , Al ₂ O ₃ in the range of 10 to 20 mass %, and CaO in the range of 1 to 15 mass %, and the amount is 45 to 55 mass % relative to the total amount of glass fibers. A glass material containing SiO ₂ in the range of % by mass, B ₂ O ₃ in the range of 20 to 35 mass %, Al ₂ O ₃ in the range of 10 to 20 mass %, and CaO in the range of 3 to 10 mass % It is more preferable to consist of

In addition, in the present invention, the glass composition is measured by ICP emission spectrometry. Specifically, the Si content and B content are obtained by dissolving a weighed and collected glass cloth sample with sodium carbonate and then dissolving it with dilute nitric acid to determine the volume, and measuring the resulting sample by ICP emission spectroscopy. In addition, the Fe content is determined by dissolving a weighed and collected glass cloth sample by an alkaline dissolution method, and measuring the obtained sample by ICP emission spectroscopy. In addition, the Al content, Ca content, and Mg content were measured by heating and decomposing the glass cloth sample collected by weighing it with sulfuric acid, nitric acid, and hydrogen fluoride, then dissolving it with dilute nitric acid, and measuring the obtained sample by ICP emission spectrometry. and get it Additionally, iCAP 6300 Duo manufactured by Thermo Fisher Company can be used as an ICP emission spectroscopic analysis device.

In the glass cloth of the present invention, the average fiber diameter of the glass long fibers is not particularly limited. The average fiber diameter of the glass long fiber is, for example, 2 to 7 μm, and from the viewpoint of making it easier to achieve the effect of the present invention, 2.5 to 5.5 μm is preferable, and 3 to 5 μm is more preferable. It can be heard.

Additionally, in the glass cloth of the present invention, the number of long glass fibers constituting the glass yarn is not particularly limited. For example, the number is 20 to 200, and from the viewpoint of making it easier to achieve the effect of the present invention, the number is preferably 20 to 100, and more preferably 20 to 50 or 30 to 50. .

The average fiber diameter and number of glass long fibers are measured and calculated as follows. That is, prepare two pieces of glass cloth to be measured, cut into 30cm squares, one side for oblique observation and the other for weft observation, and each is embedded in epoxy-based cold embedding resin and hardened. . Next, the glass cloth embedded in the epoxy-based cold embedding resin was polished to the extent that the warp or weft threads could be observed, and the average fiber diameter was measured using SEM (trade name: JSM-6390A, manufactured by Nippon Electronics Co., Ltd.) at a magnification of 2000. The number is observed at a magnification of 500 times.

(1) Average fiber diameter of glass yarn (㎛)

30 pieces are randomly selected for each of the warp and weft yarns, the diameters are measured by observing the cross-section of the long fibers included in each of the 30 glass yarns, and the average value is calculated to obtain the average fiber diameter of the glass long fibers of the warp and weft yarns. Do it as

(2) Number (pieces)

30 each of the warp and weft yarns are randomly selected, the number of long fibers contained in each of the 30 glass yarns is measured, the average value is calculated, and this is taken as the number of warp and weft yarns.

Additionally, in the glass cloth of the present invention, the number of glass yarns is not particularly limited. For example, it is 0.5 to 25 tex, and from the viewpoint of making it easier to exhibit the effect of the present invention, 0.5 to 12 tex is preferable, 0.5 to 5 tex is more preferable, and 0.8 to 3.2 tex is still more preferable. You can. In addition, in the present invention, the count of glass thread is a value measured and calculated according to the method specified in "7.1 Count" of Japanese Industrial Standard JIS R 3420 2013 "General Test Method for Glass Fiber".

[Density and texture of glass cloth]

The glass cloth of the present invention has a warp density and a weft density of 70 pieces/25 mm or more. As a result, the shear stress G in the weft direction of the glass cloth can be increased, making it easier for the residual shear bending rate 2HG/G to satisfy 1.4 (deg ^-1 ) or less. From the same viewpoint, the warp density and weft density are preferably 85 pieces/25 mm or more. The upper limit of the warp density and weft density is not particularly limited, but from the viewpoint of reducing the mass of the glass cloth, it is preferably 130 pieces/25 mm or less, and more preferably 120 pieces/25 mm or less. The warp density and weft density are specifically 70 to 130 pieces/25 mm, preferably 85 to 120 pieces/25 mm. In addition, in the present invention, the warp density and weft density are values measured and calculated according to the method specified in "7.9 Density (Weaving Density)" of the Japanese Industrial Standard JIS R 3420 2013 "General Test Method for Glass Fiber" am.

Additionally, glass cloth is manufactured with more tension applied to the warp yarn than to the weft yarn during manufacture. Accordingly, since the weft thread of the glass cloth is manufactured with relatively weak tension, the unevenness of the thread width when viewed from the plane direction of the glass cloth becomes larger than that of the warp thread. Therefore, in the present invention, the weft yarn can also be defined as the glass yarn whose yarn width is more uneven when viewed in a planar direction among warp yarns and weft yarns.

The weaving structure of the glass cloth is not particularly limited, and examples include plain weave, weave weave, twill weave, square weave, and plain weave. Among them, plain weave is preferable.

[Surface treatment of glass cloth]

The glass cloth of the present invention contains (A) polyoxyalkylene bisphenol A ether, and (B) a silane coupling agent having an acrylic group or methacryl group on at least a portion of the surface of the glass long fiber. By including these, the bending hysteresis 2HB in the weft direction of the glass cloth can be reduced, and the residual curvature 2HB/B can be set to 0.5 (cm ^-1 ) or less. Furthermore, by including these, the shear hysteresis 2HG in the weft direction of the glass cloth can be reduced, and the residual shear deflection rate 2HG/G can be set to 1.4 (deg ^-1 ) or less.

Polyoxyalkylene bisphenol A ether is a compound represented by the following general formula (1).

In General Formula (1), R ¹ and R ² are the same or different and represent an alkylene group. The number of carbon atoms in the alkylene group is, for example, 2 to 4, preferably 2 or 3, and more preferably 2. In General Formula (1), n ¹ and n ² represent the average added mole number of alkylene oxide. As n ¹ and n ² , for example, they are 2 to 50, preferably 4 to 30, and more preferably 6 to 20. n ¹ and n ² may each be different values, but may be approximately the same value. As one aspect of polyoxyalkylene bisphenol A ether, in General Formula (1), R ¹ and R ² are the same alkylene group, and n ¹ and n ² have substantially the same numerical value.

Preferred examples of the polyoxyalkylene bisphenol A ether used in the present invention include polyoxyethylene bisphenol A ether or polyoxypropylene bisphenol A ether. Among them, polyoxyethylene bisphenol A ether is more preferable from the viewpoint of excellent lubricity and making it easier to reduce fluffing of the glass cloth. The average added mole number of alkylene oxide in the polyoxyalkylene bisphenol A ether used in the present invention is, for example, 2 to 40, preferably 4 to 30, and more preferably 6 to 20. Here, the average added mole number of alkylene oxide in polyoxyalkylene bisphenol A ether is the average value of the total number of alkylene oxides contained in the two polyalkylene oxide chains constituting polyoxyalkylene bisphenol A ether. .

As a silane coupling agent having an acrylic group or a methacryl group, a compound represented by the following general formula (2) can be mentioned.

In General Formula (2), R ³ represents a hydrogen atom or a methyl group. In general formula (2), R ⁴ is It is an alkylene group having 1 to 6 carbon atoms. R ⁴ is preferably an alkylene group with 1 to 4 carbon atoms, more preferably an alkylene group with 2 to 4 carbon atoms, and even more preferably an alkylene group with 3 carbon atoms. The alkylene group for R ⁴ may be linear or branched, but is preferably branched. In General Formula (2), R ⁵ and R ⁶ each independently represent an alkyl group having 1 to 5 carbon atoms. R ⁵ and R ⁶ are preferably an alkyl group with 1 to 3 carbon atoms, more preferably an alkyl group with 1 or 2 carbon atoms, and even more preferably a methyl group. In General Formula (2), m represents an integer of 0 or more and 2 or less. As m, preferably 0 or 1, more preferably 0.

A silane coupling agent having an acrylic group or a methacryl group, specifically, 3-acryloxypropyltrimethoxysilane (in General Formula (2), R ³ is H, R ⁴ is -C ₃ H ₆ -, m 0, a compound where R ⁶ is -CH ₃ ), 3-methacryloxypropyltrimethoxysilane (in General Formula (2), R ³ is -CH ₃ , R ⁴ is -C ₃ H ₆ -, m 0, a compound where R ⁶ is -CH ₃ ), 3-acryloxypropylmethyldimethoxysilane (in General Formula (2), R ³ is H, R ⁴ is -C ₃ H ₆ -, m is 1, Compound where R ⁵ and R ⁶ are -CH ₃ ), 3-methacryloxypropylmethyldimethoxysilane (in General Formula (2), R ³ is -CH ₃ , R ⁴ is -C ₃ H ₆ -, m 1, R ⁵ and R ⁶ are -CH ₃ compounds), 3-acryloxypropyltriethoxysilane (in general formula (2), R ³ is H, R ⁴ is -C ₃ H ₆ -, m 0, a compound where R ⁶ is -C ₂ H ₅ ), 3-methacryloxypropyltriethoxysilane (in General Formula (2), R ³ is -CH ₃ and R ⁴ is -C ₃ H ₆ - , m is 0, and R ⁶ is -C ₂ H ₅ ), etc. are exemplified. Among these, 3-acryloxypropyltrimethoxysilane and 3-methacryloxypropyltrimethoxysilane are preferable.

In the glass cloth of the present invention, the ratio of (A) polyoxyalkylene bisphenol A ether and (B) silane coupling agent having an acrylic group or methacryl group is, for example, (A) polyoxyalkylene bisphenol A ether. The total amount of (B) silane coupling agent having an acrylic group or methacryl group may be 1 to 1000 parts by mass, preferably 10 to 500 parts by mass, more preferably 50 to 400 parts by mass. .

In addition, in the glass cloth of the present invention, the mass ratio of (A) polyoxyalkylene bisphenol A ether per 100 mass parts of the total amount of components adhering to the surface of the glass long fiber is, for example, 10 to 90 mass parts, Preferably it is 10 to 80 parts by mass, more preferably 10 to 50 parts by mass, and even more preferably 15 to 45 parts by mass.

In addition, in the glass cloth of the present invention, the mass ratio of the silane coupling agent having an acrylic group or methacryl group (B) per 100 parts by mass of the total amount of components adhering to the surface of the glass long fiber is, for example, 10 to 90. Parts by mass, preferably 20 to 80 parts by mass.

In the glass cloth of the present invention, at least a portion of the surface of the glass long fiber may contain a silane coupling agent other than (B) a silane coupling agent having an acrylic group or a methacryl group. (B) Silane coupling agents other than the silane coupling agent having an acrylic group or methacryl group include a silane coupling agent having an amino group, a silane coupling agent having a vinyl group, a silane coupling agent having a phenyl group, a silane coupling agent having a glycidoxy group, A silane coupling agent having an isocyanate group, a silane coupling agent having a mercapto group, a silane coupling agent having a styryl group, a silane coupling agent having a ureide group, etc. can be mentioned. In particular, the combined use of (B) a silane coupling agent having an acrylic group or methacryl group and a silane coupling agent having an amino group or vinyl group is preferable because the adhesion to the matrix resin when used as a prepreg is likely to be improved more easily.

Examples of the silane coupling agent having an organic functional group containing an amino group include compounds represented by the following general formula (3) and salts thereof.

In General Formula (3), X represents an organic functional group having one or more amino groups. In General Formula (3), p represents an integer of 0 or more and 2 or less. As p, it is preferably 0 or 1, and more preferably 0. In General Formula (3), R ⁷ and R ⁸ each independently represent an alkyl group having 1 to 5 carbon atoms. R ⁷ and R ⁸ are preferably an alkyl group having 1 to 3 carbon atoms, and more preferably an alkyl group having 1 or 2 carbon atoms.

As a silane coupling agent having an amino group, specifically, N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane and its hydrochloride salt, N-β-(N-vinylbenzylaminoethyl)- γ-Aminopropyltriethoxysilane and its hydrochloride salt, N-β-(N-benzylaminoethyl)-γ-aminopropyltrimethoxysilane and its hydrochloride salt, N-β-(N-benzylaminoethyl)-γ- Aminopropyltriethoxysilane and its hydrochloride salt, γ-(2-aminoethyl)aminopropyltrimethoxysilane, γ-(2-aminoethyl)aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, γ -Single compounds such as (2-aminoethyl)aminopropyltriethoxysilane, or mixtures thereof can be mentioned. Among these, N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane and its hydrochloride salt, N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltriethoxysilane, and Its hydrochloride salt, N-β-(N-benzylaminoethyl)-γ-aminopropyltrimethoxysilane and its hydrochloride salt, N-β-(N-benzylaminoethyl)-γ-aminopropyltriethoxysilane and its hydrochloride salt This is more preferable.

Examples of the silane coupling agent having a vinyl group or a styryl group include a compound represented by the following general formula (4).

In General Formula (4), Y represents an organic functional group containing one or more vinyl groups or styryl groups. In general formula (4), R ⁹ is an alkyl group having 1 to 8 carbon atoms, and is preferably a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, or t-butyl group. Additionally, in general formula (4), OR ¹⁰ is It is an alkoxy group having 1 to 8 carbon atoms which may have a substituent, and is preferably a methoxy group, an ethoxy group, or a methoxyethoxy group. In General Formula (4), q is an integer of 0 to 2, and is preferably 0.

Specific examples of silane coupling agents having a vinyl or styryl group include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane, and styryltrimethoxysilane.

In the glass cloth of the present invention, the mass ratio of the total amount of the silane coupling agent to the total amount of 100 parts by mass of the components adhering to the surface of the glass long fiber is, for example, 10 to 90 parts by mass, preferably 40 to 90 parts by mass. , more preferably 45 to 85 parts by mass. Here, the total amount of the silane coupling agent is the total mass of (B) the silane coupling agent having an acrylic group or methacryl group and other silane coupling agents included as necessary.

In addition, in the glass cloth of the present invention, the mass ratio of the silane coupling agent having an acrylic group or methacryl group (B) per 100 parts by mass of the total amount of the silane coupling agent adhering to the surface of the glass long fiber is, for example, 10. to 100 parts by mass, preferably 30 to 100 parts by mass, more preferably 50 to 100 parts by mass. Here, the total amount of the silane coupling agent is the total mass of (B) the silane coupling agent having an acrylic group or methacryl group and other silane coupling agents included as necessary.

Additionally, in the glass cloth of the present invention, at least a portion of the surface of the long glass fiber may contain a softener, antistatic agent, or surfactant as needed. The softener, antistatic agent, and surfactant can be selected appropriately depending on the type of surface treatment agent used.

[Physical properties of glass cloth, etc.]

The glass cloth of the present invention has a carbon content of 0.4 to 1.5 mass%. The carbon amount serves as an indicator of the adhesion amount of the surface treatment agent containing (A) polyoxyalkylene bisphenol A ether and (B) a silane coupling agent having an acrylic group or methacryl group. By setting the carbon amount within the above range, the bending rigidity B can be effectively increased, and the residual curvature 2HB/B becomes possible to be 0.5 (cm ^-1 ) or less. The amount of carbon is more preferably 0.5 to 1.2% by mass, and even more preferably 0.6 to 1.1% by mass, from the viewpoint that the adhesion to the matrix resin when used as a prepreg is easily improved. In the present invention, the carbon amount is a value measured in the following procedure. First, using a total carbon measurement device, glass cloth was burned and reduced under oxygen circulation at a reaction temperature of 850°C and a reduction temperature of 600°C, and the total organic carbon, which was chromatographically separated by a porous polymer bead packed column, was detected by a thermal conductivity detector (TCD). Quantify. Next, the carbon content of the glass cloth is calculated from a calibration curve prepared using the elemental quantitative standard sample acetanilide as a standard sample.

In the glass cloth of the present invention, the loss on ignition is not particularly limited, but includes, for example, 0.2 to 1.5 mass%, preferably 0.5 to 1.5 mass%, more preferably 1.0 to 1.4 mass%, 1.05 to 1.3 mass% is more preferable. In the present invention, the loss on ignition is a value measured according to the method specified in "7.3.2 Loss on ignition" of the Japanese Industrial Standard JIS R 3420:2013 "General test methods for glass fibers".

The mass of the glass cloth of the present invention is not particularly limited, but examples include 5 to 50 g/m2, preferably 5 to 30 g/m2, and 5 to 20 g/m2. It is more desirable. In the present invention, the mass of the glass cloth is measured and is a value according to the method specified in "7.2 Mass (mass) of cloth and mat" of Japanese Industrial Standard JIS R 3420:2013 "General test method for glass fiber".

The thickness (μm) of the glass cloth of the present invention is not particularly limited, but examples include 5 to 50 μm, preferably 5 to 30 μm, and more preferably 9 to 25 μm. In the present invention, the thickness of the glass cloth is determined according to “7.10.1 Cloth Thickness” of Japanese Industrial Standard JIS R 3420:2013 “General Test Method for Glass Fiber” using an electronic micrometer with a minimum display value of 0.001 mm. This is a value measured in accordance with the prescribed method B.

In the glass cloth of the present invention, the tensile strength in the diagonal direction includes 20 to 120 N/25 mm, preferably 25 to 110 N/25 mm, and more preferably 30 to 100 N/25 mm. In addition, the above tensile strength was determined by measuring the length of the test piece using a constant-speed extension type tensile tester in accordance with the method specified in "7.4.2 Cross Case" of Japanese Industrial Standard JIS R 3420:2013 "General Test Methods for Glass Fibers". 25 cm, the width of the test piece (width before unwinding the thread from both ends) is 30 mm, the holding interval is 15 cm, the width of the test piece (width after unwinding the thread from both ends) is 25 mm, the constant tensile speed is 200 mm/min, and the glass cloth This is a value obtained by measuring five times each in the warp direction and taking the average value as the tensile strength in the warp direction of the glass cloth (N/25 mm).

Additionally, in the production of glass cloth, deoiling treatment of the binding agent and adhesive necessary for weaving the warp and weft yarns is performed. This deoiling treatment is called thermal cleaning treatment. The tensile strength of the glass cloth subjected to the heat cleaning treatment is reduced to less than half compared to that before the heat cleaning treatment. In addition, the above-described appropriate range of tensile strength of 20 to 120 N/25 mm represents the tensile strength of the glass cloth that has been heat cleaned, and is significantly different from the glass cloth that has not been heat cleaned.

The glass cloth of the present invention is a glass cloth composed of glass yarns made of a plurality of glass long fibers as warp and weft yarns, and (A) polyoxyalkylene bisphenol A ether and (B) on at least a portion of the surface of the glass long fibers. ) It contains a silane coupling agent having an acrylic group or a methacryl group, and the weaving density of the glass cloth is 70 pieces/25 mm or more, and the carbon content of the glass cloth is 0.4 to 1.5% by mass, the residual curvature is 2HB/B. is 0.5cm- ¹ or less, and the residual shear deflection rate 2HG/G can be satisfied at 1.4 (deg ^-1 ) or less. A more appropriate range of the residual curvature 2HB/B provided by the glass cloth of the present invention includes 0.1 cm ^-1 or more and 0.5 cm ^-1 or less, and 0.2 cm ^-1 or more and 0.45 cm ^-1 or less is more preferable. In addition, as a more appropriate range of the residual shear deflection rate 2HG/G provided by the glass cloth of the present invention, 0.1 deg ^-1 or more and 1.4 deg ^-1 or less are preferable, and 0.5 deg ^-1 or more and 1.2 deg ^-1 or less are more preferable. , 0.7deg ^-1 or more and 1.1deg ^-1 or less are more preferable.

In the present invention, the residual curvature 2HB/B of the glass cloth is a value measured using a KES-FB2 pure bending tester manufactured by Kato Tech Co., Ltd. Below, a method for measuring the residual curvature 2HB/B of glass cloth will be described with reference to FIG. 1. The left drawing of Figure 1(a) is a schematic diagram of a glass cloth bent into an arc shape using a pure bending tester, and the right drawing of Figure 1(a) is a schematic diagram of a state in which a glass cloth is bent into an arc shape using a pure bending tester. This is a diagram schematically showing the bending moment (M). Figure 1(b) is an example of a bending hysteresis curve obtained using a pure bending tester. First, prepare two sheets of glass cloth cut into 20 cm x 20 cm, and overlap the two sheets so that each warp and weft are in the same direction to serve as a test sample. In addition, if it is not possible to immediately distinguish between the warp and weft yarns in the glass cloth, as described above, it can be judged that the one with the larger uneven yarn width when viewed in the planar direction corresponds to the weft yarn. Fix the test sample so that the distance between the chucks is 1cm. When fixing, the weft of the test sample is evenly wound on the chuck from both ends in the longitudinal direction (i.e., the direction in which the weft thread continues). Next, as shown in Figure 1(a), the weft yarn is bent into an arc shape at a constant speed (strain speed (0.5 ^-1 /sec)) until the curvature K = +2.5cm- ¹ , and then the weft yarn has a maximum curvature of -2.5cm. A bending test is performed by bending the material into an arc shape to the opposite side at a constant speed (strain rate (0.5 ^-1 /sec)) until ^-1 and then returning it to its original state, and measuring the bending moment that occurs along with the change in curvature ( Figure 1(a)). The bending test is performed for one cycle, and a bending hysteresis curve (vertical axis: bending moment, horizontal axis: curvature) as shown in Fig. 1(b) is obtained as a bending characteristic value. From the bending hysteresis curve, the bending rigidity B per unit length (gf·cm ² /cm) and the hysteresis width 2HB (gf·cm/cm) are obtained. This measurement is conducted in an environment of 23℃ and 50%RH. In addition, in the present invention, the bending stiffness B per unit length is the average slope of the derivative value of the bending moment (M) measured between curvature K = +0.5cm ^-1 and +1.5cm ^-1 , and the hysteresis width 2HB is the curvature Calculated as the width of hysteresis at K = +1.0cm ^-1 (see Figure 1(b)). For this measurement, for example, the measurement is performed using the KES-FB SYSTEM (Ver. 7.18WJ) data measurement program, and B and 2HB are calculated using the KES-FB CALC (Ver. 7.07J) data calculation program. You can. The above measurement is performed five times using 10 different glass cloth samples, and the average value of the residual shear bending rate 2HB/B, which is the ratio of the bending hysteresis 2hb in the weft direction to the bending stress B in the weft direction, is obtained.

In addition, in the present invention, the residual shear deflection rate of the glass cloth, 2HG/G, is a value measured using a KES-FB1 tensile shear tester manufactured by Kato Tech Co., Ltd. Below, a method for measuring the residual shear deflection rate 2HG/G of glass cloth will be described with reference to FIG. 2. Figure 2(a) is a schematic diagram of a state in which glass cloth has been sheared and deformed to a shear angle ϕ using a tensile shear tester, and Figure 2(b) is an example of a shear hysteresis curve obtained using a tensile shear tester. First, prepare two pieces of glass cloth cut into 20cm x 20cm, and overlap the two pieces so that the warp and weft threads are in the same direction to serve as a test sample. In addition, if it is not possible to immediately distinguish between the warp and weft yarns in the glass cloth, as described above, it can be judged that the one with the larger uneven yarn width when viewed in the planar direction corresponds to the weft yarn. Fix the test sample so that the distance between the chucks is 5cm. When fixing, the weft of the test sample is evenly wound on the chuck from both ends in the longitudinal direction (i.e., the direction in which the weft thread continues). Next, as shown in Figure 2, with a forced load (W) of 10 gf/cm applied in the longitudinal direction of the weft (i.e., the direction in which the weft is continuous), the shear angle ϕ is applied in the longitudinal direction of the warp (i.e., in the direction in which the warp is continuous). = +8° at a constant speed (0.00834°/sec), then deformed in the reverse direction to a shear angle ϕ = -8°, then returned again, and the shear force that occurs with the change in shear angle is measured (Figure 2 (see (a)). The shear test is performed for one cycle, and the shear hysteresis curve (vertical axis: shear force, horizontal axis: shear angle) as shown in Fig. 2(b) is obtained as the shear characteristic value. From the shear hysteresis curve, the shear stress G (gf/cm/deg) in the weft direction and the hysteresis width 2HG (gf/cm) are determined. This measurement is conducted in an environment of 23℃ and 50%RH. In addition, the shear stress per unit length G is the average slope of the differential value of the shear force (Fs) measured between shear angle ϕ = +0.5 and +2.5, and the width of hysteresis 2HG is the width of hysteresis at shear angle ϕ = +0.5 ( It is calculated as (see Figure 2(b)). For this measurement, for example, the measurement is performed using the KES-FB SYSTEM (Ver. 7.18WJ) data measurement program, and G and 2HG are calculated using the KES-FB CALC (Ver. 7.07J) data calculation program. You can. The above measurements were performed five times using 10 different glass cloth samples, and the residual shear deflection rate 2HG was obtained, which is the ratio of the shear hysteresis 2HG (gf/cm) in the weft direction to the shear stress in the weft direction G (gf/cm/deg). /Find the average value of G.

[Method of manufacturing glass cloth]

Next, an example of the method for manufacturing the glass cloth of the present invention will be described. First, a glass cloth is woven using glass yarns made of a plurality of long glass fibers as warp and weft yarns. The weaving method may be any conventionally known method. For example, after subjecting the warp yarn to a warping process and an adhesion process, the weft yarn is woven through a jet loom (e.g., an air jet loom, a water jet loom). etc.), sludge loom, rapier loom, etc.

And, if necessary, opening treatment and/or heat cleaning treatment may be performed. Methods for the opening treatment include, for example, opening the obtained glass cloth using the pressure of a water stream, using water (e.g. degassed water, ion exchanged water, deionized water, electrolyzed cationic water or electrolyzed anionic water, etc.) as a medium. Examples include card-opening treatment using high-frequency vibration and processing using pressure using a roll. This opening treatment may be performed simultaneously with weaving, or may be performed after weaving. In addition, the opening treatment may be performed before or after the heat cleaning treatment, or may be performed simultaneously with the heat cleaning treatment, and may be performed simultaneously with the surface treatment described later or after the surface treatment described later. In addition, as a method of adjusting the degree of opening of the warp and weft threads, a known method can be adopted, including a method of adjusting the warp tension, a pinch expander in the horizontal direction, a curved rubber roller, a rotating rolling roller, a Mirabo roller, or a tenter. A method of performing opening while adjusting and providing tension balance in the warp direction and the weft direction by employing a method such as, or a method of combining these methods, can be mentioned.

If a substance (e.g., bundling agent, etc.) that impairs the adhesion or impregnation of the matrix resin when used as a prepreg or printed wiring board is attached to the woven glass cloth, it may be subjected to heat cleaning treatment, for example. It is desirable to remove the above substances. Additionally, heat cleaning treatment may be omitted for glass cloth woven from glass yarn to which a surface treatment agent described later has been applied to the primary and secondary adhesives. The temperature conditions for the heat cleaning treatment are preferably 350°C or higher, more preferably 350 to 500°C, and even more preferably 380 to 450°C. In addition, the time of heat cleaning treatment can be set appropriately according to the temperature conditions to be adopted. For example, in the case where the glass cloth is made into a roll product (a product with glass cloth wound around a core), the heat cleaning process is performed as is on the roll product. In some cases, it is 20 to 60 hours, preferably 24 to 48 hours, and more preferably 24 to 36 hours.

Then, in the method for producing a glass cloth of the present invention, surface treatment is performed on the prepared glass cloth. For surface treatment, first, prepare a treatment agent.

The treatment agent to be prepared includes a component and a solvent that adhere to the surface of the glass long fiber, and specifically, (A) polyoxyalkylene bisphenol A ether and/or (B) a silane coupling agent having an acrylic group or methacryl group. , and a solvent. There is no particular limitation on the type of solvent, but examples include water.

The content of (A) polyoxyalkylene bisphenol A ether in the treatment agent is not particularly limited, but is, for example, 1 to 30 g/L, preferably 2 to 20 g/L, more preferably 3 to 15 g. /L can be mentioned. In addition, the content of the silane coupling agent (B) having an acrylic group or methacryl group in the treatment agent is not particularly limited, but is, for example, 3 to 40 g/L, preferably 5 to 35 g/L, more preferably. Examples include 10 to 30 g/L.

The ratio of the mass of (A) polyoxyalkylene bisphenol A ether to the mass of all non-volatile components contained in the treatment agent is not particularly limited, but examples include 10 to 90 mass%, and 20% by mass. The range is preferably from 10 to 80 mass%, more preferably from 10 to 50 mass%, and more preferably from 15 to 45 mass%. The ratio of the mass of the silane coupling agent (B) having an acrylic group or a methacryl group to the mass of all non-volatile components contained in the treatment agent is not particularly limited, and examples include 10 to 90 mass%. and is preferably 20 to 80 mass%. In addition, the ratio of the mass of all silane coupling agents to the mass of all non-volatile components contained in the treatment agent is not particularly limited, but examples include 10 to 90 mass%, and 40 to 90 mass%. is preferably mentioned, and 45 to 85 mass% is more preferably mentioned. In addition, the ratio of the total mass of the silane coupling agent having an acrylic group or methacryl group to the total 100 parts by mass of all silane coupling agents contained in the treatment agent is not particularly limited, but can be, for example, 10 to 100 parts by mass, 30 to 100 parts by mass is preferable, and 50 to 100 parts by mass is more preferable. In addition, in the present invention, the "non-volatile component" is an absolutely dried component that is heat-treated at 110°C under normal pressure to remove the solvent, etc. and reaches a constant weight, and is ultimately used as a glass sheet in the glass cloth of the present invention. It is a component that remains attached to the surface of the fiber.

The glass cloth can be surface treated by applying the treatment agent to the glass cloth by impregnating, applying, or spraying the prepared treatment agent onto the glass cloth, and then drying it. In the surface treatment process, the surface may be treated by applying a mixture of (A) and (B) to the prepared glass cloth and drying it, or the (A) and (B) may be used as separate treatment agents in two steps. The surface may be treated by dividing and drying.

[Form/Use of Glass Cloth]

In one embodiment of the glass cloth of the present invention, it is provided as a roll-shaped elongated glass cloth with a glass cloth wound around a core. When the glass cloth of the present invention is a roll-shaped long glass cloth, the length and width of the glass cloth are not particularly limited, but for example, the length is 10 to 4000 m, preferably 50 to 3000 m, more preferably 100 to 4000 m. Examples include 2000 m, and the width is 10 to 200 cm, preferably 30 to 150 cm, and more preferably 50 to 130 cm.

The glass cloth of the present invention is suitably used as a fiber substrate for prepreg. In particular, the glass cloth of the present invention is particularly suitable as a fiber base material for prepreg for printed wiring boards. The prepreg using the glass cloth of the present invention will be described later.

2. Prepreg

The prepreg of the present invention includes the glass cloth and a thermosetting resin impregnated in the glass cloth.

The thermosetting resin is not particularly limited as long as it is a resin that hardens by heat, but examples include phenol resin, epoxy resin, halogen-free epoxy resin, cyanate resin, maleimide resin, bismaleimide resin, modified bismaleimide resin, Isocyanate resin, benzocyclobutene resin, vinyl resin, bismaleimide triazine resin, phenol resin, thermosetting polyphenylene ether resin, etc. are mentioned. Thermosetting resins may be used individually, or two or more types may be used together.

Additionally, the prepreg of the present invention may contain an inorganic filler. Examples of the inorganic filler include silica such as natural silica, fused silica, amorphous silica, and hollow silica; boehmite; Molybdenum compounds such as molybdenum oxide and zinc molybdate; Glass fillers such as alumina, talc, calcined talc, mica, short glass fibers, and spherical glass (glass fillers made of E glass, T glass, UT glass, S glass, D glass, NE glass, L glass, LU glass, etc.) ), etc.

The prepreg of the present invention can be suitably used as a constituent material of a printed wiring board.

Example

Below, the present invention will be described in detail by showing examples and comparative examples. However, the present invention is not limited to the examples.

1. Measurement and evaluation methods

1-1. Average fiber diameter and number of long glass fibers

The average fiber diameter of the long glass fiber and the number of long glass fibers constituting the glass yarn were measured as follows. That is, two sheets of the obtained glass cloth were prepared by cutting them into 30 cm squares, one side was used for warp observation, the other side was used for weft observation, and each was coated with epoxy-based cold embedding resin (trade name: epoxy resin cloth manufactured by Storuas Co., Ltd.) It was embedded in Cifix-40 and cured. Next, the glass cloth embedded in the epoxy-based cold embedding resin was polished to the extent that the warp or weft threads could be observed, and the average was obtained using a scanning electron microscope (SEM) (trade name: JSM-6390A, manufactured by Nippon Electronics Co., Ltd.). The fiber diameter was measured by observing at a magnification of 2000 times and the number of fibers was measured at a magnification of 500 times.

(1) Average fiber diameter of long glass fiber (㎛)

30 pieces were randomly selected for each of the warp and weft yarns, the diameters were measured by observing the cross-section of the long fibers included in each of the 30 glass yarns, and the average value was calculated to obtain the average fiber diameter of the glass long fibers of the warp and weft yarns. I did it.

(2) Number of long glass fibers (pieces)

Thirty pieces were randomly selected for each of the warp and weft yarns, and the total number of long fibers included in each of the 30 glass yarns was measured and the average value was calculated, which was taken as the number of glass long fibers of the warp and weft yarns.

1-2. Weave density of glass cloth

The weave density of the glass cloth was measured according to the method specified in "7.9 Density (Weave Density)" of the Japanese Industrial Standard JIS R 3420:2013 "General Test Methods for Glass Fibers". Specifically, the measurement target was a position 50 mm or more away from the edge and edge of the glass cloth, the measurement interval was set to 10 mm or more and 200 mm or less, and the number of all threads within the set measurement interval was measured. This was done as a single measurement, moved to another location that did not contain the previously measured threads, and all thread counts within the measurement interval were measured two additional times in the same manner. For each of the three measurements, the number of threads per 25 mm was calculated according to the formula below, and the average value of the three measurements was calculated.

1-3. Number of glass yarns

The count of the glass thread in the glass cloth was measured according to the method specified in "7.1 Count" of the Japanese Industrial Standard JIS R 3420 2013 "General Test Method for Glass Fiber". Specifically, first, 500 m of glass yarn was collected from the yarn winding device, and this was used as a test piece. The test piece was placed flat, placed in a muffle furnace, fired at 625°C for 25 minutes, left to cool in a desiccator, and the mass of the test piece was measured. The count was calculated according to the formula below.

1-4. mass of glass cloth

The mass of the glass cloth was measured according to the method specified in "7.2 Mass of cloth and mat (mass)" of Japanese Industrial Standard JIS R 3420:2013 "General test method for glass fiber". Specifically, a square test piece with an area of 100 cm ² is taken at a distance of 50 mm or more from the edge width of the glass cloth, the test piece is dried at 105°C for 1 hour, the mass of the test piece is measured, and 1 is obtained according to the formula below. The mass per m2 was calculated.

1-5. thickness of glass cloth

The thickness of the glass cloth was measured according to Method B specified in “7.10.1 Cloth Thickness” of the Japanese Industrial Standard JIS R 3420:2013 “General Test Methods for Glass Fibers”. Specifically, the thickness at both ends and at a location 50 mm or more inside from the side width was measured using an electronic micrometer with a minimum display value of 0.001 mm.

1-6. Ignition loss of glass cloth

The ignition loss of the glass cloth was measured according to the method specified in "7.3.2 Ignition loss" of the Japanese Industrial Standard JIS R 3420:2013 "General test methods for glass fibers". Specifically, a test piece of 100 cm ² or more was cut from a portion 10 mm or more inside from a corner or end, placed in a dryer at 105°C, and dried for 30 minutes. After drying, the test piece was moved into a desiccator, allowed to cool to room temperature, and the mass was measured. Drying, cooling, and measurement were repeated until the mass became constant, and the mass of the dried test piece was determined. Next, the dried test piece was placed in a muffle furnace adjusted to 625°C and heated for more than 10 minutes. After taking out the test piece from the muffle furnace, it was moved to a desiccator, left to cool, and the mass of the test piece was measured. Heating, cooling, and measurement were repeated until the mass became constant, and the mass of the test piece after drying and heating was determined. The loss on ignition (%) was calculated according to the formula below.

1-7. Tensile Strength of Glass Cloth

The tensile strength of the glass cloth was determined in accordance with the method specified in “7.4.2 Cloth Case” of Japanese Industrial Standard JIS R 3420:2013 “General Test Methods for Glass Fibers” using a constant-speed extension type tensile tester (Intesco Co., Ltd.) Using a test piece (made by Kaisha), the length of the test piece is 25 cm, the width of the test piece (width before unwinding the thread from both ends) is 30 mm, the holding interval is 15 cm, the width of the test piece (width after unraveling the thread from both ends) is 25 mm, and the constant tensile speed is set. was set to 200 mm/min, the breaking strength was measured five times in the inclination direction of the glass cloth, and the average value of the measured values was taken as the tensile strength of the glass cloth (N/25 mm).

1-8. Carbon content of glass cloth

Using a total carbon measuring device (SUMIGRAPH (registered trademark) NCH-22F manufactured by Sumika Bunseki Center), the glass cloth was burned and reduced under oxygen circulation at a reaction temperature of 850°C and a reduction temperature of 600°C, and then transferred to a porous polymer bead packed column. The chromatographically separated total organic carbon was quantified using a thermal conductivity detector (TCD). The carbon content of the glass cloth was calculated from a calibration curve prepared using the elemental quantification standard sample acetanilide as a standard sample.

1-9. Non-uniformity of yarn width of warp and weft yarns

To determine the unevenness of thread width, cut the glass cloth into 20cm Measure the yarn width at a point, repeat the remaining 18 measurements every 1 cm in the longitudinal direction of the glass yarn from that point, measure the yarn width at a total of 19 points, and calculate the coefficient of variation CV value (=standard deviation/ average value) was obtained. This measurement was performed on the three glass yarns constituting the warp yarn, and the average value of the CV values of the three warp yarns was obtained. Additionally, the CV value of the yarn width of the glass yarn constituting the weft yarn was obtained in the same manner. It is determined that the larger the CV value, the greater the non-uniformity of the actual width.

1-10. Residual curvature 2HB/B

The residual curvature 2HB/B was measured using a KES-FB2 pure bending tester manufactured by Kato Tech Co., Ltd. as a bending measurement tester. Specifically, two sheets of glass cloth were prepared by cutting them into 20 cm x 20 cm, and the two sheets were overlapped so that the warp and weft yarns were in the same direction to serve as test samples. The test sample was fixed so that the distance between the chucks was 1 cm. At the time of fixing, the weft thread of the test sample was evenly wound around the chuck from both ends in the longitudinal direction. Next, as shown in Figure 1(a), the weft is bent into an arc shape at a constant speed (strain speed (0.5 ^-1 /sec)) until the curvature K = +2.5cm ^-1 , and then the weft has a maximum curvature of -2.5cm. A bending test was performed by bending the material into an arc shape to the opposite side at a constant speed (strain rate (0.5 ^-1 /sec)) until ^-1 and then returning it to its original state, and the bending moment that occurred with the change in curvature was measured ( Figure 1(a)). The bending test was performed for one cycle, and a bending hysteresis curve as shown in Fig. 1(b) was obtained as a bending characteristic value, and the bending rigidity per unit length B (gf·cm ² /cm) and the hysteresis width 2HB (gf·cm/ cm) was obtained. This measurement was conducted in an environment of 23°C and 50%RH. In addition, in the present invention, B is the average slope of the differential value of the bending moment (M) measured between curvature K = +0.5cm ^-1 and +1.5cm ^-1 , and 2HB is the curvature K = +1.0cm ^-1 It was calculated as the width of hysteresis (see Fig. 1(b)). In this test, measurements were made using the KES-FB SYSTEM (Ver. 7.18WJ) data measurement program, and B and 2HB were calculated using the KES-FB CALC (Ver. 7.07J) data calculation program. The above measurement was performed 5 times using 10 different glass cloth samples, and the average value of the residual shear deflection rate of 2HB/B was obtained.

1-11. Residual shear deflection rate 2HG/G

The residual shear deflection rate 2HG/G was measured using KES-FB1 manufactured by Kato Tech Co., Ltd. as a tensile shear tester. Specifically, two sheets of glass cloth were prepared by cutting them into 20 cm x 20 cm, and the two sheets were overlapped so that each warp and weft were in the same direction to serve as a test sample. The test sample was fixed so that the distance between the chucks was 5 cm. At the time of fixing, the weft thread of the test sample was evenly wound around the chuck from both ends in the longitudinal direction. Next, as shown in Figure 2, with a forced load (W) of 10 gf/cm applied to the longitudinal direction of the weft (i.e., the direction in which the weft continues), the shear angle ϕ is applied in the longitudinal direction of the warp (i.e., in the direction in which the warp is continuous). = +8° at a constant speed (0.00834°/sec), then deformed in the reverse direction to a shear angle ϕ = -8°, then returned again, and the shear force that occurred with the change in shear angle was measured (Figure 2 (see (a)). The shear test was performed for one cycle, and a shear hysteresis curve as shown in Fig. 2(b) was obtained as a shear characteristic value, and the shear stress in the weft direction G (gf/cm/deg) and the hysteresis width 2HG (gf/cm) were obtained. Saved. This measurement was conducted in an environment of 23°C and 50%RH. In addition, G is the average slope of the differential value of the shear force (Fs) measured between shear angle ϕ = +0.5 and +2.5, and 2HG is the width of hysteresis at shear angle ϕ = +0.5 (see Figure 2(b)). calculated. In this measurement, measurements were made using the KES-FB SYSTEM (Ver. 7.18WJ) data measurement program, and G and 2HG were calculated using the KES-FB CALC (Ver. 7.07J) data calculation program. The above measurement was performed 5 times using 10 different glass cloth samples, and the average value of the residual shear deflection rate of 2HG/G was obtained.

1-12. Evaluation of the level of occurrence of vertical stripes in glass cloth

The obtained glass cloth was visually inspected at random for a length of 1000 m to observe the number of vertical stripes, the number of vertical stripes per 100 m in length was calculated, and evaluated according to the following criteria. Additionally, vertical stripes measuring more than 100 cm in length were counted.

A: The number of vertical stripes was 0.0 per 100m.

B: The number of vertical stripes was 0.1 to 0.5 per 100 m.

C: The number of vertical stripes exceeded 0.6/100m.

1-13. Evaluation of the presence or absence of diagonal wrinkles in glass cloth

The obtained glass cloth was visually inspected at random for a length of 1000 m, the number of diagonal wrinkles was observed, and the presence or absence of diagonal wrinkles was evaluated. Additionally, diagonal wrinkles that were 10 cm or longer in length were counted.

A: The number of diagonal wrinkles was not observed.

B: The number of diagonal wrinkles was observed.

2. Manufacturing of glass cloth

Example 1

As warp and weft yarns, Composition: Composed of low dielectric constant/low dielectric loss tangent glass material containing SiO ₂ : 51 mass%, Al ₂ O ₃ : 13 mass%, CaO: 8 mass%, B ₂ O ₃ : 23 mass%, and the balance 5 mass%. and glass yarn consisting of glass long fibers with an average fiber diameter of 4.0 μm and a number of 100 was used. The glass yarn was woven on an air jet loom to obtain a plain weave glass cloth roll (a long glass cloth in a roll wound around a core) with a warp density of 75/25mm and a weft density of 76/25mm. Next, a heat cleaning treatment was performed on the obtained glass cloth roll by heating it for 30 hours under conditions of an atmospheric temperature of 400°C. There were no vertical stripes or diagonal wrinkles in the glass cloth after heat cleaning.

Next, the treatment agent of Formulation 1 was prepared as a surface treatment agent. The composition ratio of the non-volatile component of the treatment agent is shown in Table 1.

(Prescription 1)

N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane hydrochloride (trade name Cyra Ace (registered trademark) S-350, manufactured by JNC Corporation, non-volatile component 30%): 9.0 g /L

3-Methacryloxypropyltrimethoxysilane (trade name: Cyra Ace (registered trademark) S-710, manufactured by JNC Corporation, non-volatile component 98%): 13.5 g/L

Polyoxyethylene bisphenol A ether (product name GF690 manufactured by Yoshimura Yuka Chemical Co., Ltd., non-volatile component 70%): 5.2 g/L

Balance: pure

Glass cloth that had been subjected to heat cleaning treatment was impregnated with the treatment agent of Formulation 1 while applying a tension of 150 N/m in the longitudinal direction of the warp (the direction in which the warp continues), and a nip pressure of 35 N/cm ² was applied. It was squeezed into a roll and dried at a temperature of 120°C. Next, after performing an opening treatment with a high-pressure spray, it was impregnated again with the treatment agent of Formulation 1, squeezed with a nip roll with a nip pressure of 35 N/cm ² , and dried at a temperature of 120°C to obtain a glass cloth.

The obtained glass cloth has a larger yarn width unevenness in the weft than the warp, a tensile strength in the warp direction of 96N/25mm, a residual curvature in the weft direction of 2HB/B of 0.41 (cm ^-1 ), and a residual shear bending ratio in the weft direction of 2HG/G. It was 0.99 (deg ^-1 ), the loss on ignition was 1.16 mass%, and the carbon amount was 0.72 mass%.

[Example 2]

As warp and weft yarns, low dielectric constant/low dielectric constant containing composition: SiO ₂ : 51 mass%, Al ₂ O ₃ : 13 mass%, CaO: 8 mass%, B ₂ O ₃ : 23 mass%, and balance 5 mass%. Glass yarn made of a tangent glass material, with an average fiber diameter of 4.0 μm, and 100 long glass fibers was used. Glass yarn was woven on an air jet loom to obtain a plain weave glass cloth roll with a warp density of 75/25mm and a weft density of 76/25mm. Next, a heat cleaning treatment was performed on the obtained glass cloth roll by heating it for 30 hours under conditions of an atmospheric temperature of 400°C. There were no vertical stripes or diagonal wrinkles in the glass cloth after heat cleaning.

Next, the treatment agent of Formulation 2 was prepared as a surface treatment agent. The composition ratio of the non-volatile component of the treatment agent is shown in Table 1.

(Prescription 2)

3-Methacryloxypropyltrimethoxysilane (trade name: Cyra Ace (registered trademark) S710, manufactured by JNC Corporation, non-volatile component 98%): 6.75 g/L

Vinyltrimethoxysilane (product name Cyra Ace (registered trademark) S210, manufactured by JNC Corporation, non-volatile component 99%): 6.0 g/L

Polyoxyethylene bisphenol A ether (product name GF690 manufactured by Yoshimura Yuka Chemical Co., Ltd., non-volatile component 70%): 15.7 g/L

Polyalkylene polyamine fatty acid amide (trade name KSK-2240, manufactured by Lion Specialty Chemicals Co., Ltd., non-volatile component 30%): 5.0 g/L

Balance: pure

The glass cloth that had been subjected to the heat cleaning treatment was impregnated with the treatment agent of Formulation 2 while applying a tension of 150 N/m in the longitudinal direction of the warp, squeezed out with a nip roll with a nip pressure of 35 N/cm ² , and dried at a temperature of 120°C. Next, after performing an opening treatment with a high-pressure spray, it was impregnated again with the treatment agent of Formulation 2, squeezed with a nip roll with a nip pressure of 35 N/cm ² , and dried at a temperature of 120°C to obtain a glass cloth.

The obtained glass cloth has a larger yarn width unevenness in the weft than the warp, a tensile strength in the warp direction of 81N/25mm, a residual curvature in the weft direction of 2HB/B of 0.36 (cm ^-1 ), and a residual shear bending ratio in the weft direction of 2HG/G. It was 0.94 (deg ^-1 ), the loss on ignition was 1.25 mass%, and the carbon amount was 0.96 mass%.

[Example 3]

Composition as warp and weft: low dielectric constant/low dielectric loss tangent containing SiO ₂ : 51 mass%, Al ₂ O ₃ : 13 mass%, CaO: 8 mass%, B ₂ O ₃ : 23 mass%, balance 5 mass% Glass yarn made of glass material, with an average fiber diameter of 4.0 μm, and 100 glass long fibers was used. Glass yarn was woven on an air jet loom to obtain a plain weave glass cloth roll with a warp density of 75/25mm and a weft density of 76/25mm. Next, a heat cleaning treatment was performed on the obtained glass cloth roll by heating it for 30 hours under conditions of an atmospheric temperature of 400°C. There were no vertical stripes or diagonal wrinkles in the glass cloth after heat cleaning.

Next, the treatment agent of Formulation 3 was prepared as a surface treatment agent. The composition ratio of the non-volatile component of the treatment agent is shown in Table 1.

(Prescription 3)

3-Methacryloxypropyltrimethoxysilane (trade name: Cyra Ace (registered trademark) S-710, manufactured by JNC Corporation, non-volatile component 98%): 13.5 g/L

Polyoxyethylene bisphenol A ether (product name GF690 manufactured by Yoshimura Yuka Chemical Co., Ltd., non-volatile component 70%): 5.2 g/L

Balance: pure

The glass cloth subjected to the heat cleaning treatment was impregnated with the treatment agent of Formulation 3 while applying a tension of 150 N/m in the longitudinal direction of the warp, squeezed with a nip roll with a nip pressure of 35 N/cm ² , and dried at a temperature of 120°C. Next, after performing an opening treatment with a high-pressure spray, it was impregnated again with the treatment agent of Formulation 3, squeezed with a nip roll with a nip pressure of 35 N/cm ² , and dried at a temperature of 120°C to obtain a glass cloth.

The obtained glass cloth has a larger yarn width unevenness in the weft than the warp, a tensile strength in the warp direction of 84N/25mm, a residual curvature in the weft direction of 2HB/B of 0.34 (cm ^-1 ), and a residual shear bending ratio in the weft direction of 2HG/G. It was 1.02 (deg ^-1 ), the loss on ignition was 1.10 mass%, and the carbon amount was 0.65 mass%.

[Example 4]

Composition as warp and weft: SiO ₂ : 49% by mass, Al ₂ O ₃ : 14% by mass, CaO: 6% by mass, B ₂ O ₃ : 28% by mass, Glass yarn made of a low-dielectric constant/low-dielectric loss tangent glass material containing the balance of 3% by mass, and made of glass long fibers with an average fiber diameter of 4.0 μm and a number of 50 was used. Glass yarn was woven on an air jet loom to obtain a plain weave glass cloth roll with a warp density of 95/25mm and a weft density of 95/25mm. Next, a heat cleaning treatment was performed on the obtained glass cloth roll by heating it for 30 hours under conditions of an atmospheric temperature of 400°C. There were no vertical stripes or diagonal wrinkles in the glass cloth after heat cleaning.

Next, the treatment agent of Formulation 1 above was prepared as a surface treatment agent. The composition ratio of the non-volatile component of the treatment agent is shown in Table 1.

The glass cloth that had been subjected to the heat cleaning treatment was impregnated with the treatment agent of Formulation 1 while applying a tension of 150 N/m in the longitudinal direction of the warp, squeezed out with a nip roll with a nip pressure of 35 N/cm ² , and dried at a temperature of 120°C. Next, after performing an opening treatment with a high-pressure spray, it was impregnated again with the treatment agent of Formulation 1, squeezed with a nip roll with a nip pressure of 35 N/cm ² , and dried at a temperature of 120°C to obtain a glass cloth.

The obtained glass cloth has a larger yarn width unevenness in the weft than the warp, a tensile strength in the warp direction of 49N/25mm, a residual curvature in the weft direction of 2HB/B of 0.40 (cm ^-1 ), and a residual shear bending ratio in the weft direction of 2HG/G. It was 0.96 (deg ^-1 ), the loss on ignition was 1.13 mass%, and the carbon amount was 0.64 mass%.

[Example 5]

Composition as warp and weft: SiO ₂ : 49% by mass, Al ₂ O ₃ : 14% by mass, CaO: 6% by mass, B ₂ O ₃ : 28% by mass, Glass yarn made of a low-dielectric constant/low-dielectric loss tangent glass material containing the balance of 3% by mass, and made of glass long fibers with an average fiber diameter of 4.0 μm and a number of 50 was used. Glass yarn was woven on an air jet loom to obtain a plain weave glass cloth roll with a warp density of 95/25mm and a weft density of 95/25mm. Next, a heat cleaning treatment was performed on the obtained glass cloth roll by heating it for 30 hours under conditions of an atmospheric temperature of 400°C. There were no vertical stripes or diagonal wrinkles in the glass cloth after heat cleaning.

Next, the treatment agent of Formulation 2 above was prepared as a surface treatment agent. In addition, the composition ratio of the non-volatile component of the processing agent is shown in Table 1.

The glass cloth that had been subjected to the heat cleaning treatment was impregnated with the treatment agent of Formulation 2 while applying a tension of 150 N/m in the longitudinal direction of the warp, squeezed out with a nip roll with a nip pressure of 35 N/cm ² , and dried at a temperature of 120°C. Next, after performing an opening treatment with a high-pressure spray, it was impregnated again with the treatment agent of Formulation 2, squeezed with a nip roll with a nip pressure of 35 N/cm ² , and dried at a temperature of 120°C to obtain a glass cloth.

The obtained glass cloth has a larger yarn width unevenness in the weft than the warp, a tensile strength in the warp direction of 50N/25mm, a residual curvature in the weft direction of 2HB/B of 0.43 (cm ^-1 ), and a residual shear bending ratio in the weft direction of 2HG/G. It was 0.93 (deg ^-1 ), the loss on ignition was 1.35 mass%, and the carbon amount was 1.06 mass%.

[Example 6]

Composition as warp and weft: SiO ₂ : 49% by mass, Al ₂ O ₃ : 14% by mass, CaO: 6% by mass, B ₂ O ₃ : 28% by mass, low dielectric constant/low dielectric loss tangent containing 3% by mass. Glass yarn made of glass material, with an average fiber diameter of 4.0 μm, and 50 glass long fibers was used. Glass yarn was woven on an air jet loom to obtain a plain weave glass cloth roll with a warp density of 95/25mm and a weft density of 95/25mm. Next, a heat cleaning treatment was performed on the obtained glass cloth roll by heating it for 30 hours under conditions of an atmospheric temperature of 400°C. There were no vertical stripes or diagonal wrinkles in the glass cloth after heat cleaning.

Next, the treatment agent of Formulation 3 above was prepared as a surface treatment agent. The composition ratio of the non-volatile component of the treatment agent is shown in Table 2.

The glass cloth subjected to the heat cleaning treatment was impregnated with the treatment agent of Formulation 3 while applying a tension of 150 N/m in the longitudinal direction of the warp, squeezed with a nip roll with a nip pressure of 35 N/cm ² , and dried at a temperature of 120°C. Next, after performing an opening treatment with a high-pressure spray, it was impregnated again with the treatment agent of Formulation 3, squeezed with a nip roll with a nip pressure of 35 N/cm ² , and dried at a temperature of 120°C to obtain a glass cloth.

The obtained glass cloth has greater unevenness in thread width than the warp yarn, the tensile strength in the warp direction is 52N/25mm, the residual curvature in the weft direction is 2HB/B of 0.41 (cm ^-1 ), and the residual shear bending rate in the weft direction is 2HG/G. It was 1.07 (deg ^-1 ), the loss on ignition was 1.06 mass%, and the carbon amount was 0.70 mass%.

[Example 7]

Composition as warp and weft: SiO ₂ : 50% by mass, Al ₂ O ₃ : 15% by mass, CaO: 5% by mass, B ₂ O ₃ : 27% by mass, Glass yarn made of a low-dielectric constant/low-dielectric loss tangent glass material containing 3% by mass of the balance, and made of glass long fibers with an average fiber diameter of 4.0 μm and a number of 40 was used. Glass yarn was woven on an air jet loom to obtain a plain weave glass cloth roll with a warp density of 95/25mm and a weft density of 95/25mm. Next, a heat cleaning treatment was performed on the obtained glass cloth roll by heating it for 30 hours under conditions of an atmospheric temperature of 400°C. There were no vertical stripes or diagonal wrinkles in the glass cloth after heat cleaning.

Next, the treatment agent of Formulation 1 above was prepared as a surface treatment agent. In addition, the composition ratio of the non-volatile component of the processing agent is shown in Table 2.

The glass cloth that had been subjected to the heat cleaning treatment was impregnated with the treatment agent of Formulation 1 while applying a tension of 150 N/m in the longitudinal direction of the warp, squeezed out with a nip roll with a nip pressure of 35 N/cm ² , and dried at a temperature of 120°C. Next, after performing an opening treatment with a high-pressure spray, it was impregnated again with the treatment agent of Formulation 1, squeezed with a nip roll with a nip pressure of 35 N/cm ² , and dried at a temperature of 120°C to obtain a glass cloth.

The obtained glass cloth has a larger yarn width unevenness in the weft than the warp, a tensile strength in the warp direction of 36N/25mm, a residual curvature in the weft direction of 2HB/B of 0.44 (cm ^-1 ), and a residual shear bending ratio in the weft direction of 2HG/G. It was 0.89 (deg ^-1 ), the loss on ignition was 1.17 mass%, and the carbon amount was 0.80 mass%.

[Example 8]

Composition as warp and weft: SiO ₂ : 50% by mass, Al ₂ O ₃ : 15% by mass, CaO: 5% by mass, B ₂ O ₃ : 27% by mass, Glass yarn made of a low-dielectric constant/low-dielectric loss tangent glass material containing 3% by mass of the balance, and made of glass long fibers with an average fiber diameter of 4.0 μm and a number of 40 was used. Glass yarn was woven on an air jet loom to obtain a plain weave glass cloth roll with a warp density of 95/25mm and a weft density of 95/25mm. Next, a heat cleaning treatment was performed on the obtained glass cloth roll by heating it for 30 hours under conditions of an atmospheric temperature of 400°C. There were no vertical stripes or diagonal wrinkles in the glass cloth after heat cleaning.

Next, the treatment agent of Formulation 2 above was prepared as a surface treatment agent. The composition ratio of the non-volatile component of the treatment agent is shown in Table 2.

The glass cloth that had been subjected to the heat cleaning treatment was impregnated with the treatment agent of Formulation 2 while applying a tension of 150 N/m in the longitudinal direction of the warp, squeezed out with a nip roll with a nip pressure of 35 N/cm ² , and dried at a temperature of 120°C. Next, after performing an opening treatment with a high-pressure spray, it was impregnated again with the treatment agent of Formulation 2, squeezed with a nip roll with a nip pressure of 35 N/cm ² , and dried at a temperature of 120°C to obtain a glass cloth.

The obtained glass cloth has a larger yarn width unevenness in the weft than the warp, a tensile strength in the warp direction of 36N/25mm, a residual curvature in the weft direction of 2HB/B of 0.49 (cm ^-1 ), and a residual shear bending ratio in the weft direction of 2HG/G. It was 0.89 (deg ^-1 ), the loss on ignition was 1.30 mass%, and the carbon amount was 0.92 mass%.

[Example 9]

Composition as warp and weft: SiO ₂ : 50% by mass, Al ₂ O ₃ : 15% by mass, CaO: 5% by mass, B ₂ O ₃ : 27% by mass, Glass yarn made of a low-dielectric constant/low-dielectric loss tangent glass material containing 3% by mass of the balance, and made of glass long fibers with an average fiber diameter of 4.0 μm and a number of 40 was used. Glass yarn was woven on an air jet loom to obtain a plain weave glass cloth roll with a warp density of 95/25mm and a weft density of 95/25mm. Next, a heat cleaning treatment was performed on the obtained glass cloth roll by heating it for 30 hours under conditions of an atmospheric temperature of 400°C. There were no vertical stripes or diagonal wrinkles in the glass cloth after heat cleaning.

Next, the treatment agent of Formulation 3 above was prepared as a surface treatment agent. In addition, the composition ratio of the non-volatile component of the processing agent is shown in Table 2.

The glass cloth subjected to the heat cleaning treatment was impregnated with the treatment agent of Formulation 3 while applying a tension of 150 N/m in the longitudinal direction of the warp, squeezed with a nip roll with a nip pressure of 35 N/cm ² , and dried at a temperature of 120°C. Next, after performing an opening treatment with a high-pressure spray, it was impregnated again with the treatment agent of Formulation 3, squeezed with a nip roll with a nip pressure of 35 N/cm ² , and dried at a temperature of 120°C to obtain a glass cloth.

The obtained glass cloth has a larger yarn width unevenness in the weft than the warp, a tensile strength in the warp direction of 39N/25mm, a residual curvature in the weft direction of 2HB/B of 0.49 (cm ^-1 ), and a residual shear bending ratio in the weft direction of 2HG/G. It was 1.01 (deg ^-1 ), the loss on ignition was 1.18 mass%, and the carbon amount was 0.66 mass%.

[Example 10]

As warp and weft yarns, composition: SiO ₂ : It is composed of E glass containing 54% by mass, Al ₂ O ₃ : 14% by mass, CaO: 23% by mass, MgO: 1% by mass, B ₂ O ₃ : 6% by mass, and the remainder is 2% by mass, and the average fiber diameter is Glass yarn consisting of 3.6 ㎛ long glass fibers with a number of 38 was used. Glass yarn was woven on an air jet loom to obtain a plain weave glass cloth roll with a warp density of 105/25mm and a weft density of 110/25mm. Next, a heat cleaning treatment was performed on the obtained glass cloth roll by heating it for 30 hours under conditions of an atmospheric temperature of 400°C. There were no vertical stripes or diagonal wrinkles in the glass cloth after heat cleaning.

Next, the treatment agent of Formulation 1 above was prepared as a surface treatment agent. In addition, the composition ratio of the non-volatile component of the processing agent is shown in Table 2.

The glass cloth that had been subjected to the heat cleaning treatment was impregnated with the treatment agent of Formulation 1 while applying a tension of 150 N/m in the longitudinal direction of the warp, squeezed out with a nip roll with a nip pressure of 35 N/cm ² , and dried at a temperature of 120°C. Next, after performing an opening treatment with a high-pressure spray, it was impregnated again with the treatment agent of Formulation 1, squeezed with a nip roll with a nip pressure of 35 N/cm ² , and dried at a temperature of 120°C to obtain a glass cloth.

The obtained glass cloth has greater unevenness in thread width than the warp yarn, the tensile strength in the warp direction is 51N/25mm, the residual curvature in the weft direction is 2HB/B is 0.48 (cm ^-1 ), and the residual shear bending rate in the weft direction is 2HG/G. It was 1.03 (deg ^-1 ), the loss on ignition was 0.61 mass%, and the carbon amount was 0.73 mass%.

[Comparative Example 1]

Composition as warp and weft: low dielectric constant/low dielectric loss tangent containing SiO ₂ : 51 mass%, Al ₂ O ₃ : 13 mass%, CaO: 8 mass%, B ₂ O ₃ : 23 mass%, balance 5 mass% Glass yarn made of glass material, with an average fiber diameter of 4.0 μm, and 100 glass long fibers was used. Glass yarn was woven on an air jet loom to obtain a plain weave glass cloth roll with a warp density of 75/25mm and a weft density of 76/25mm. Next, a heat cleaning treatment was performed on the obtained glass cloth roll by heating it for 30 hours under conditions of an atmospheric temperature of 400°C. There were no vertical stripes or diagonal wrinkles in the glass cloth after heat cleaning.

Next, the treatment agent of Formulation 4 was prepared as a surface treatment agent. The composition ratio of the non-volatile component of the treatment agent is shown in Table 3.

(Prescription 4)

N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane hydrochloride (trade name Cyra Ace (registered trademark) S-350, manufactured by JNC Corporation, non-volatile component 30%): 9.0 g /L

Trimethoxyphenylsilane (product name Z6124 manufactured by DuPont, Toray, Specialty, Materials Co., Ltd., non-volatile component 90%): 14.7 g/L

Balance: pure

The glass cloth subjected to the heat cleaning treatment was impregnated with the treatment agent of Formulation 4 while applying a tension of 150 N/m in the longitudinal direction of the warp, squeezed with a nip roll with a nip pressure of 35 N/cm ² , and dried at a temperature of 120°C. Next, after performing an opening treatment with a high-pressure spray, it was impregnated again with the treatment agent of Formulation 4, squeezed with a nip roll with a nip pressure of 35 N/cm ² , and dried at a temperature of 120°C to obtain a glass cloth.

The obtained glass cloth has a larger yarn width unevenness in the weft than the warp, a tensile strength in the warp direction of 96N/25mm, a residual curvature in the weft direction of 2HB/B of 0.34 (cm ^-1 ), and a residual shear bending ratio in the weft direction of 2HG/G. It was 2.96 (deg ^-1 ), the loss on ignition was 0.99 mass%, and the carbon amount was 0.43 mass%.

[Comparative Example 2]

Composition as warp and weft: SiO ₂ : 51% by mass, Al ₂ O ₃ : 13% by mass, CaO: 8% by mass, B ₂ O ₃ : 23% by mass, Glass yarn made of a low-dielectric constant/low-dielectric loss tangent glass material containing the balance of 5% by mass, and made of glass long fibers with an average fiber diameter of 4.0 μm and a number of 100 was used. Glass yarn was woven on an air jet loom to obtain a plain weave glass cloth roll with a warp density of 75/25mm and a weft density of 76/25mm. Next, a heat cleaning treatment was performed on the obtained glass cloth roll by heating it for 30 hours under conditions of an atmospheric temperature of 400°C. There were no vertical stripes or diagonal wrinkles in the glass cloth after heat cleaning.

Next, a treatment agent of Formulation 5 was prepared as a surface treatment agent. The composition ratio of the non-volatile component of the treatment agent is shown in Table 3.

(Prescription 5)

N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane hydrochloride (trade name Cyra Ace (registered trademark) S-350, manufactured by JNC Corporation, non-volatile component 30%): 9.0 g /L

Balance: pure

The glass cloth subjected to the heat cleaning treatment was impregnated with the treatment agent of Formulation 5 while applying a tension of 150 N/m in the longitudinal direction of the warp, squeezed with a nip roll with a nip pressure of 35 N/cm ² , and dried at a temperature of 120°C. Next, after performing an opening treatment with a high-pressure spray, it was impregnated again with the treatment agent of Formulation 5, squeezed with a nip roll with a nip pressure of 35 N/cm ² , and dried at a temperature of 120°C to obtain a glass cloth.

The obtained glass cloth has greater unevenness in yarn width than the warp yarn, the tensile strength in the warp direction is 78N/25mm, the residual curvature in the weft direction is 2HB/B of 0.62 (cm ^-1 ), and the residual shear bending ratio in the weft direction is 2HG/G. It was 1.83 (deg ^-1 ), the loss on ignition was 0.63 mass%, and the carbon amount was 0.14 mass%.

[Comparative Example 3]

Composition as warp and weft: low dielectric constant/low dielectric loss tangent containing SiO ₂ : 51 mass%, Al ₂ O ₃ : 13 mass%, CaO: 8 mass%, B ₂ O ₃ : 23 mass%, balance 5 mass% Glass yarn made of glass material, with an average fiber diameter of 4.0 μm, and 100 glass long fibers was used. Glass yarn was woven on an air jet loom to obtain a plain weave glass cloth roll with a warp density of 75/25mm and a weft density of 76/25mm. Next, a heat cleaning treatment was performed on the obtained glass cloth roll by heating it for 30 hours under conditions of an atmospheric temperature of 400°C. There were no vertical stripes or diagonal wrinkles in the glass cloth after heat cleaning.

Next, a treatment agent of Formulation 6 was prepared as a surface treatment agent. The composition ratio of the non-volatile component of the treatment agent is shown in Table 3.

(Prescription 6)

N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane hydrochloride (trade name Cyra Ace (registered trademark) S-350, manufactured by JNC Corporation, non-volatile component 30%): 3. 0 g /L

Polyoxyethylene bisphenol A ether (product name GF690 manufactured by Yoshimura Yuka Chemical Co., Ltd., non-volatile component 70%): 5.2 g/L

Balance: pure

The glass cloth that had been subjected to the heat cleaning treatment was impregnated with the treatment agent of Formulation 6 while applying a tension of 150 N/m in the longitudinal direction of the warp, squeezed with a nip roll with a nip pressure of 35 N/cm ² , and dried at a temperature of 120°C. Next, after performing an opening treatment with a high-pressure spray, it was impregnated again with the treatment agent of Formulation 6, squeezed with a nip roll with a nip pressure of 35 N/cm ² , and dried at a temperature of 120°C to obtain a glass cloth.

The obtained glass cloth has a larger yarn width unevenness in the weft than the warp, a tensile strength in the warp direction of 92N/25mm, a residual curvature in the weft direction of 2HB/B of 1.42 (cm ^-1 ), and a residual shear bending ratio in the weft direction of 2HG/G. It was 1.09 (deg ^-1 ), the loss on ignition was 0.85 mass%, and the carbon amount was 0.24 mass%.

[Comparative Example 4]

As warp and weft yarns, composition: SiO ₂ : It is composed of a low-dielectric constant/low-dielectric loss tangent glass material containing 49% by mass, Al ₂ O ₃ : 14% by mass, CaO: 6% by mass, B ₂ O ₃ : 28% by mass, and the balance 3% by mass, and has an average fiber diameter of Glass yarn consisting of 4.0 μm long glass fibers with a number of 50 was used. Glass yarn was woven on an air jet loom to obtain a plain weave glass cloth roll with a warp density of 95/25mm and a weft density of 95/25mm. Next, a heat cleaning treatment was performed on the obtained glass cloth roll by heating it for 30 hours under conditions of an atmospheric temperature of 400°C. There were no vertical stripes or diagonal wrinkles in the glass cloth after heat cleaning.

Next, the treatment agent of Formulation 5 above was prepared as a surface treatment agent. In addition, the composition ratio of the non-volatile component of the processing agent is shown in Table 3.

The glass cloth subjected to the heat cleaning treatment was impregnated with the treatment agent of Formulation 5 while applying a tension of 150 N/m in the longitudinal direction of the warp, squeezed with a nip roll with a nip pressure of 35 N/cm ² , and dried at a temperature of 120°C. Next, after performing an opening treatment with a high-pressure spray, it was impregnated again with the treatment agent of Formulation 5, squeezed with a nip roll with a nip pressure of 35 N/cm ² , and dried at a temperature of 120°C to obtain a glass cloth.

The obtained glass cloth has a larger yarn width unevenness in the weft than the warp, a tensile strength in the warp direction of 53N/25mm, a residual curvature in the weft direction of 2HB/B of 0.58 (cm ^-1 ), and a residual shear bending ratio in the weft direction of 2HG/G. It was 1.79 (deg ^-1 ), the loss on ignition was 0.65 mass%, and the carbon amount was 0.12 mass%.

[Comparative Example 5]

Composition as warp and weft: SiO ₂ : It is composed of a low-dielectric constant/low-dielectric loss tangent glass material containing 50% by mass, Al ₂ O ₃ : 15% by mass, CaO: 5% by mass, B ₂ O ₃ : 27% by mass, and the balance 3% by mass, and has an average fiber diameter of Glass yarn consisting of 4.0 μm long glass fibers with a number of 40 was used. Glass yarn was woven on an air jet loom to obtain a plain weave glass cloth roll with a warp density of 95/25mm and a weft density of 95/25mm. Next, a heat cleaning treatment was performed on the obtained glass cloth roll by heating it for 30 hours under conditions of an atmospheric temperature of 400°C. There were no vertical stripes or diagonal wrinkles in the glass cloth after heat cleaning.

Next, the treatment agent of Formulation 5 above was prepared as a surface treatment agent. The composition ratio of the non-volatile component of the treatment agent is shown in Table 3.

The glass cloth subjected to the heat cleaning treatment was impregnated with the treatment agent of Formulation 5 while applying a tension of 150 N/m in the longitudinal direction of the warp, squeezed with a nip roll with a nip pressure of 35 N/cm ² , and dried at a temperature of 120°C. Next, after performing an opening treatment with a high-pressure spray, it was impregnated again with the treatment agent of Formulation 5, squeezed with a nip roll with a nip pressure of 35 N/cm ² , and dried at a temperature of 120°C to obtain a glass cloth.

The obtained glass cloth has a larger yarn width unevenness in the weft than the warp, a tensile strength in the warp direction of 30N/25mm, a residual curvature in the weft direction of 2HB/B of 0.56 (cm ^-1 ), and a residual shear bending ratio in the weft direction of 2HG/G. It was 1.63 (deg ^-1 ), the loss on ignition was 0.65 mass%, and the carbon amount was 0.12 mass%.

[Comparative Example 6]

As warp and weft yarns, composition: SiO ₂ : It is composed of E glass containing 54% by mass, Al ₂ O ₃ : 14% by mass, CaO: 23% by mass, MgO: 1% by mass, B ₂ O ₃ : 6% by mass, and the remainder is 2% by mass, and the average fiber diameter is Glass yarn consisting of 3.6 ㎛ long glass fibers with a number of 38 was used. Glass yarn was woven on an air jet loom to obtain a plain weave glass cloth roll with a warp density of 105/25mm and a weft density of 110/25mm. Next, a heat cleaning treatment was performed on the obtained glass cloth roll by heating it for 30 hours under conditions of an atmospheric temperature of 400°C. There were no vertical stripes or diagonal wrinkles in the glass cloth after heat cleaning.

Next, the treatment agent of Formulation 5 above was prepared as a surface treatment agent. In addition, the composition ratio of the non-volatile component of the processing agent is shown in Table 3.

The glass cloth subjected to the heat cleaning treatment was impregnated with the treatment agent of Formulation 5 while applying a tension of 150 N/m in the longitudinal direction of the warp, squeezed with a nip roll with a nip pressure of 35 N/cm ² , and dried at a temperature of 120°C. Next, after performing an opening treatment with a high-pressure spray, it was impregnated again with the treatment agent of Formulation 5, squeezed with a nip roll with a nip pressure of 35 N/cm ² , and dried at a temperature of 120°C to obtain a glass cloth.

The obtained glass cloth has a larger yarn width unevenness in the weft than the warp, a tensile strength in the warp direction of 43N/25mm, a residual curvature in the weft direction of 2HB/B of 0.79 (cm ^-1 ), and a residual shear bending ratio in the weft direction of 2HG/G. It was 1.59 (deg ^-1 ), the loss on ignition was 0.23 mass%, and the carbon amount was 0.21 mass%.

3. Results

For each glass cloth, the average fiber diameter and number of glass long fibers contained in the glass yarn used, weaving density, number of glass yarns used, mass, thickness, loss on ignition, tensile strength and carbon content, residual curvature 2HB/B, residual The shear deflection rate of 2HG/G, the occurrence of longitudinal stripes, and the occurrence of diagonal wrinkles were evaluated. The evaluation results are shown in Table 1, Table 2, and Table 3.

The glass cloth of Examples 1 to 10 is a glass cloth composed of glass yarns made of a plurality of glass long fibers as warp and weft yarns, and at least a portion of the surface of the glass long fibers is coated with (A) polyoxyalkylene bisphenol A ether, and (B) A silane coupling agent having an acrylic group or a methacryl group, the weaving density of the glass cloth is 70 pieces/25 mm or more, the carbon content of the glass cloth is 0.4 to 1.5 mass%, and the residual curvature is 2HB/B. It was possible to obtain a glass cloth with a residual shear deflection rate of 2HG/G of 1.4 (deg ^-1 ) or less and 0.5 (cm ^-1 ) or less. And, the glass cloths of Examples 1 to 10 were able to suppress the generation of vertical wrinkles and diagonal wrinkles.

On the other hand, the glass cloth of Comparative Example 1 had a carbon content of 0.4% by mass or more, but at least a portion of the surface of the glass long fiber contained (A) polyoxyalkylene bisphenol A ether and (B) a silane coupling agent having an acrylic group or methacryl group. Because it did not include , the residual shear deflection rate 2HG/G exceeded 1.4 (deg ^-1 ). And, the glass cloth of Comparative Example 1 was unable to suppress the generation of diagonal wrinkles.

In addition, the glass cloths of Comparative Examples 2, 4 to 6 have a carbon content of less than 0.4% by mass, and (A) polyoxyalkylene bisphenol A ether and (B) acrylic or methacrylic groups are present on at least a portion of the surface of the glass long fiber. Since it did not contain a silane coupling agent having a group, the residual curvature 2HB/B exceeded 0.5 (cm ^-1 ) and the residual shear bending ratio 2HG/G exceeded 1.4 (deg ^-1 ). And, the glass cloths of Comparative Examples 2 and 4 to 6 were unable to suppress the generation of vertical stripes and diagonal wrinkles.

The glass cloth of Comparative Example 3 had a carbon content of less than 0.4% by mass and did not contain a silane coupling agent having an acrylic or methacrylic group (B) on at least part of the surface of the long glass fiber, so the residual shear deflection rate was 2HG/ G exceeded 1.4(deg ^-1 ). And, the glass cloth of Comparative Example 3 was unable to suppress the generation of vertical stripes.

Claims (5)

A glass cloth composed of warp and weft yarns made of a plurality of long glass fibers,
At least a portion of the surface of the glass long fiber includes (A) polyoxyalkylene bisphenol A ether, and (B) a silane coupling agent having an acrylic group or methacryl group,
The warp density and weft density of the glass cloth are 70 pieces/25mm or more,
A glass cloth wherein the carbon content of the glass cloth is 0.4 to 1.5 mass%. According to claim 1,
Glass cloth with a tensile strength in the warp direction of 20 to 120 N/25 mm. The method of claim 1 or 2,
Glass cloth with a thickness of 5 to 30㎛. The method according to any one of claims 1 to 3,
Glass cloth, which is a roll-shaped long glass cloth made by winding glass cloth around a winding core. A prepreg comprising the glass cloth according to any one of claims 1 to 4 and a thermosetting resin impregnated in the glass cloth.