JP7515300B2 - Glass yarn, glass cloth manufacturing method, and glass cloth - Google Patents

Description

The present invention relates to glass yarn, a method for producing glass cloth, and glass cloth.

With the recent development of the information and communications society, data communication and/or signal processing has become large-volume and high-speed, and the dielectric constant of printed wiring boards used in electronic devices has been significantly reduced. For this reason, many low-dielectric glass cloths have been proposed for use in glass cloths that make up printed wiring boards.

For example, the low dielectric glass cloth disclosed in Patent Document 1 realizes a low dielectric constant by blending a large amount _{of B2O3} in the glass composition, as compared to the E-glass cloth that has been generally used in the past, and at the same time adjusting the blending amounts of other components such as _SiO2 .

Japanese Patent Application Laid-Open No. 11-292567

The inventors have conducted research and found that low-dielectric glass cloth made using low-dielectric glass yarn as described in Patent Document 1 has a large variation in performance or quality compared to the E-glass cloth that has been used conventionally. Such variation in the performance or quality of glass cloth also affects the quality of prepregs, laminates for printed wiring boards, and the like obtained using the same.

The present invention was made in consideration of the above problems, and aims to provide a method for producing low dielectric glass cloth with uniform, high quality, and glass yarn suitable for producing low dielectric glass cloth.

As a result of intensive research into solving the above problems, the present inventors have found that the above problems can be solved by producing a glass cloth using glass yarns having density, breaking strength and yarn width distribution within specific ranges, and have thus completed the present invention. One aspect of the present invention is listed below.
[1]
A glass yarn in which 92 to 108 glass filaments having an average diameter of 4.5 μm to 5.5 μm are bundled together,
The density is 2.2 g/ ^cm3 or more and less than 2.5 g/ ^cm3 ,
The breaking strength is 0.50 N/tex or more and 0.80 N/tex or less,
The average yarn width when measured over 50 m is 95 μm or more and 125 μm or less,
When measured over 50 m, 98.0% or more of the length is composed of yarn widths of 220 μm or less.
Glass thread.
[2]
2. The glass yarn according to item 1, wherein, when measured for 50 m, 95.0% or more of the length has a yarn width of 190 μm or less.
[3]
The silicon (Si) content is 40 to 60 mass% calculated as _SiO2 , and the boron (B) content is 15 to 40 mass% calculated _{as B2O3} .
3. The glass thread according to item 1 or 2.
[4]
4. The glass yarn according to item 3, wherein the B content is 20 to 40 mass% calculated as B ₂ O ₃ .
[5]
5. The glass yarn according to any one of items 1 to 4, having an elastic modulus of 50 GPa or more and 70 Pa or less.
[6]
Item 6. The glass yarn according to item 5, having an elastic modulus of 50 GPa or more and 63 GPa or less.
[7]
7. The glass yarn according to any one of the preceding claims, having a dielectric constant of 5.0 or less at a frequency of 1 GHz.
[8]
Item 8. A method for producing a glass cloth, comprising a step of weaving the glass yarn according to any one of items 1 to 7 as a weft yarn.
[9]
8. A glass cloth comprising the glass yarn according to any one of items 1 to 7 as a weft yarn.
[10]
10. The glass cloth according to item 9, having a dielectric constant of 5.0 or less at a frequency of 1 GHz.

The present invention provides a method for producing uniform, high-quality low dielectric glass cloth, uniform, high-quality low dielectric glass cloth, and glass yarn suitable for producing uniform, high-quality low dielectric glass cloth.

The following describes in detail an embodiment of the present invention (hereinafter referred to as the "present embodiment"); however, the present invention is not limited to this embodiment, and various modifications are possible without departing from the gist of the present invention.

[Glass thread]
The glass yarn of this embodiment is a glass yarn in which 92 to 108 glass filaments having an average diameter of 4.5 μm to 5.5 μm are bundled together, the density of the glass yarn is 2.2 g/ ^cm3 or more and less than 2.5 g/ ^cm3 , the breaking strength of the glass yarn is 0.50 N/tex or more and 0.80 N/tex or less, the average yarn width of the glass yarn when 50 m of the glass yarn is measured is 95 μm or more and 125 μm or less, and 98.0% or more of the glass yarn in the longitudinal direction when 50 m of the glass yarn is measured has a yarn width of 220 μm or less.

It has become clear that glass cloth manufactured using low-dielectric glass yarns varies in quality compared to conventional E-glass cloth, making it difficult to obtain consistently high-quality glass cloth. When glass cloth of relatively poor quality was examined in detail, it was found that glass cloth manufactured from glass yarns containing many areas with wide yarn widths in the yarn width distribution in the length direction had many coarse fluff defects in which the filaments that make up the glass yarns were broken and tangled in groups of 1 to 10 filaments.

This embodiment is based on the knowledge that the above drawbacks can be reduced by using glass yarns that have characteristics such as a relatively small distribution of yarn width and relatively few wide yarn width areas. The reason for this is that, without being bound by theory, glass yarns (weft yarns) that locally include wide yarn width areas tend to have large resistance to air or resistance due to interference with loom parts, so that the weft yarns tend to have large vibrations or ballooning motions in the direction perpendicular to the conveying direction between when they are unwound from the bobbin and when they are ejected, and it is believed that shear stress acts on the glass yarns due to friction when the weft yarn passes through loom parts such as loop guides, which makes it easy for filament breakage to occur. In addition, weft yarns that locally include wide yarn width areas are greatly affected by fluctuations in unwinding tension when unwound from the bobbin, or by the on/off of the air jet pressure that ejects the weft yarn, and therefore tend to have large tension fluctuations during the weft yarn conveying process, and it is believed that the above-mentioned vibrations or ballooning motions during the weft yarn conveying process are also likely to be large.

Furthermore, the E-glass glass yarns used up until now have a larger mass per unit length and are stronger than low-dielectric glass yarns, so the transport of the weft yarn is stable, there is less interference with loom parts, and damage sustained when interference occurs is limited. On the other hand, low-dielectric glass yarns, which are lighter and weaker in strength, tend to have larger vibrations when the weft yarn is transported due to tension fluctuations, etc., making them more susceptible to interference with loom parts and more susceptible to greater damage when they interfere with loom parts, which is thought to encourage the occurrence of filament breakage. It is thought that these effects are reflected in the quality of the woven glass cloth.

In contrast, in the present embodiment, the weft yarn is made of glass yarn having a density of 2.2 g/cm3 or ^more and less than 2.5 g/ ^cm3 , an average yarn width of 95 μm or more and 125 μm or less, and 98.0% or more of the yarn width distribution in the length direction is 220 μm or less. This reduces the degree of interference with loom components or damage caused by interference, even when a relatively light and weak glass yarn with low dielectric properties is used. This suppresses the generation of coarse fluff caused by filament breakage in the yarn path, and allows a uniform glass cloth of good quality to be obtained. When the above glass yarn is used for the warp yarn, defects such as the generation of fluff can be prevented when the warp yarn is rubbed against a yarn path guide or the like in the process of unwinding the raw yarn from the bobbin in the creel and aligning the warp yarns, and this tends to lead to stable production of good quality, which is preferable. In addition, the use of the above glass yarn for the warp yarn tends to increase the warping speed, which is preferable.

(Glass yarn density)
The density of the glass yarn is 2.2 g/cm3 or ^more and less than 2.5 g/ ^cm3 , preferably 2.2 g/ ^cm3 or more and less than 2.45 g/ ^cm3 , more preferably 2.2 g/ ^cm3 or more and 2.40 g/ ^cm3 or less, and even more preferably 2.25 g/ ^cm3 or more and 2.4 g/ ^cm3 or less.

If the density of a normal glass yarn is less than 2.5 g/ ^cm3 , when it is used as a weft yarn, the vibration or ballooning motion in the direction perpendicular to the conveying direction is likely to become large during the conveying process from when it is unwound from the bobbin to when it is sprayed out, and poor fluffing is likely to occur due to interference with loom components. However, by setting the yarn width distribution within the specific range of the present invention, the conveying trajectory of the weft yarn can be stabilized, and a high-quality glass cloth can be stably obtained.

When the glass yarn has a density of 2.2 g/ ^cm3 or more, the conveying trajectory of the weft yarn can be stabilized when the yarn width distribution is within the specific range of the present invention. The density of the glass yarn can be calculated as the density of a lump of glass per ^cm3 .

(Glass yarn width)
The average width of the glass yarn is 95 μm or more and 125 μm or less when the length of the glass yarn is 50 m. The average width is preferably 96 μm or more, more preferably 97 μm or more, and even more preferably 98 μm or more. The average width is preferably less than 125 μm, more preferably 122 μm or less, and even more preferably 120 μm or less.

In addition, in the longitudinal width distribution of the glass yarn, 98.0% or more of the yarn has a width of 220 μm or less. The preferred range of the yarn width distribution is 98.0% or more in the longitudinal direction and 210 μm or less, a more preferred range is 97.0% or more in the longitudinal direction and 200 μm or less, an even more preferred range is 97.0% or more in the longitudinal direction and 190 μm or less, and a most preferred range is 95.0% or more in the longitudinal direction and 190 μm or less.

When the average width of the glass yarn is equal to or greater than the above lower limit, the glass yarn can be used as a weft yarn and can be woven with good productivity without short picks or other defects because it properly receives the injected air during weft insertion. In addition, when the average width of the glass yarn is equal to or greater than the above lower limit, the weft yarn can be blown with a relatively gentle injection pressure, which tends to suppress the occurrence of fuzz or weaving defects in the resulting glass cloth.

In addition, since the average width of the glass yarn is equal to or less than the above upper limit, and 98.0% or more of the glass yarn has a width of 220 μm or less in the longitudinal direction of the glass yarn, when the glass yarn is used as a weft yarn, filament breakage does not occur during the transport process from when the weft yarn is unwound from the bobbin to when it is ejected, and a high-quality glass cloth with few fluff defects can be stably obtained. This is presumably because, during the transport process of the weft yarn, resistance to air or resistance due to interference with loom parts is reduced, so that the vibration or ballooning movement of the weft yarn in the direction perpendicular to the transport direction is reduced, and as a result, damage due to interference with loom parts, particularly damage sustained when the weft yarn passes while being rubbed against loop guides, etc., is reduced.

In addition, if the average width of the glass yarn is equal to or less than the upper limit value, and 98.0% or more of the glass yarn's width distribution in the length direction is 220 μm or less, the unwinding tension when unwinding the weft yarn from the bobbin tends to be kept stable, and it is presumed that the small fluctuation in tension of the transported weft yarn also works in a positive direction by minimizing the vibration or ballooning motion of the weft yarn and reducing damage to the weft yarn.

In addition, by having the average width of the glass yarn be equal to or less than the upper limit value, when the glass yarn is used as a warp yarn, it is possible to prevent defects such as the generation of fuzz when the warp yarn is rubbed against a yarn guide or the like during the process of unwinding the raw yarn from the bobbin in a creel and pulling the warp yarns together, which is preferable and tends to lead to stable production of good quality. In addition, by using the above glass yarn as a warp yarn, it is preferable that the warping speed can be increased.

(Breaking strength of glass yarn)
The breaking strength of the glass yarn is 0.50 N/tex or more and 0.80 N/tex or less. The breaking strength is preferably in the range of 0.55 N/tex or more and 0.78 N/tex or less, more preferably in the range of 0.60 N/tex or more and 0.76 N/tex or less, and even more preferably in the range of 0.65 N/tex or more and 0.75 N/tex or less.

If the breaking strength of the glass yarn is 0.50 N/tex or more, when it is used as a weft yarn, the filament is less likely to break and fuzz is less likely to occur when the weft yarn comes into contact with loom parts such as a yarn guide and is subjected to shear stress during the yarn transport process from when it is unwound from the bobbin to when it is sprayed out, or when the sprayed yarn comes into contact with loom parts such as a reed and is subjected to shear stress during the flight process.

If the breaking strength of the glass yarn is 0.80 N/tex or less, it is presumed that due to the flexibility of the glass yarn when used as a weft yarn, the vibration or balloon movement of the yarn during the yarn transport process from when the weft yarn is unwound from the bobbin to when it is ejected tends to be kept small, and fuzzing due to filament breakage is less likely to occur.

(Constitution of glass yarn)
Glass yarn is obtained by bundling a plurality of glass filaments and twisting them as necessary. In this case, glass yarn is classified as multifilament, and glass filament is classified as monofilament.

The glass yarns constituting the warp and weft threads are glass yarns consisting of 92 to 108 monofilaments with an average particle size of 4.5 to 5.5 μm. By using glass yarns with an average particle size and number of filaments within the above ranges, it is possible to manufacture glass cloth with thicknesses equivalent to the 106, 1035, and 1067 styles of conventional E-glass cloth (IPC standard (IPC-4412A): Styles 106, 1035, and 1067).

The elastic modulus of the glass yarn is preferably 50 to 70 GPa, more preferably 50 to 63 GPa, and even more preferably 53 to 63 GPa. When the elastic modulus is 50 GPa or more, the rigidity of the glass yarn is improved, and fluffing tends to be less likely to occur during the manufacturing process. Furthermore, when the elastic modulus is 70 GPa or less, the brittleness resistance of the glass yarn is improved, and fluffing tends to be less likely to occur during the manufacturing process. Furthermore, when the elastic modulus is within the above range, the glass yarn has appropriate flexibility, and when a mechanical load is applied, filament breakage and the like are less likely to occur, and fluffing and weaving defects tend to be less likely to occur.

(Composition of glass yarn components)
Elements constituting the glass yarn include Si, B, Al, Ca, Mg, P, Na, K, Ti, Zn, Fe, F, and the like.

The silicon (Si) content of the glass yarn is preferably 40 to 60 mass%, more preferably 45 to 55 mass%, even more preferably 47 to 53 mass%, and even more preferably 48 to 52 mass%, calculated as _SiO2 . Si is a component that forms the skeletal structure of the glass yarn, and when the Si content is 40 mass% or more, the strength of the glass yarn is further improved, and the breakage of the glass cloth tends to be further suppressed in the manufacturing process of the glass cloth and in the post-process such as the manufacturing of the prepreg using the glass cloth. In addition, when the Si content is 40 mass% or more, the dielectric constant of the glass cloth tends to be further reduced. On the other hand, when the Si content is 60 mass% or less, the viscosity at the time of melting is further reduced in the manufacturing process of the glass filament, and glass fibers with a more homogeneous glass composition tend to be obtained. Therefore, the obtained glass filaments are less likely to have portions that are easily devitrified or portions where bubbles are difficult to escape, and therefore the glass filaments are less likely to have portions with locally weak strength, and as a result, the glass cloth made of the glass yarn obtained by using the same is less likely to break. The Si content can be adjusted according to the amount of raw material used in producing the glass filaments.

The boron (B) content of the glass yarn, calculated as _B2O3 , is preferably 15 to ₄₀ mass%, more preferably 17 to 30 mass%, or 20 to 40 mass%, even more preferably 18 to 28 mass%, still more preferably 19 to 26 mass%, even more preferably 20 to 25 mass%, and most preferably 20.5 mass% or more and 24 mass% or less.

With a B content of 15% by mass or more, the dielectric constant tends to be lower. In addition, with a B content of 15% by mass or more, the glass cloth is improved in brittleness resistance and is given appropriate flexibility and suppleness, so that the glass yarns tend to be less likely to generate fluff when they come into contact with loom components such as the yarn guide and reed.

On the other hand, in order to maintain the strength of the glass yarn, it is preferable that the B content is 40% by mass or less. In addition, by having a B content of 40% by mass or less, the moisture absorption resistance is improved and the stability of the glass yarn surface characteristics described below is properly maintained.

The B content can be adjusted according to the amount of raw materials used in producing the glass filaments. If the conditions, amounts used, or contents may change during the production of the glass filaments, the amount of raw materials charged can be adjusted in advance in anticipation of this.

The aluminum (Al) content of the glass filament is preferably 11 to 18 mass%, more preferably 11 to 16 mass%, and even more preferably 12 to 16 mass%, calculated as Al ₂ O _3. When the Al content is within the above range, the electrical properties and strength tend to be further improved. The Al content can be adjusted according to the amount of raw material used to produce the glass filament.

The calcium (Ca) content of the glass yarn is preferably 5 to 10 mass %, preferably 5 to 9 mass %, and more preferably 5 to 8.5 mass %, calculated as CaO. When the Ca content is 5 mass % or more, the viscosity at the time of melting tends to be lower during the glass filament manufacturing process, and glass fibers with a more homogeneous glass composition tend to be obtained. Furthermore, when the Ca content is 10 mass % or less, the dielectric constant tends to be improved. The Ca content can be adjusted according to the amount of raw material used to manufacture the glass filaments.

The above contents can be measured by ICP optical emission spectroscopy. Specifically, the Si content and B content can be obtained by melting a weighed glass cloth sample with sodium carbonate, dissolving it in dilute nitric acid to a constant volume, and measuring the obtained sample by ICP optical emission spectroscopy. The Fe content can be obtained by dissolving a weighed glass cloth sample by an alkaline dissolution method to a constant volume, and measuring the obtained sample by ICP optical emission spectroscopy. Furthermore, the Al content, Ca content, P content, and Mg content can be obtained by decomposing a weighed glass cloth sample with perchloric acid, sulfuric acid, nitric acid, and hydrogen fluoride, dissolving it in dilute nitric acid to a constant volume, and measuring the obtained sample by ICP optical emission spectroscopy. The ICP optical emission spectroscopy device can be PS3520VDD II manufactured by Hitachi High-Tech Science Corporation.

(Dielectric constant of glass yarn)
The dielectric constant of the glass yarn is preferably 5.0 or less, more preferably 4.9 or less, even more preferably 4.8 or less, and particularly preferably 4.6 or less at a frequency of 1 GHz. The dielectric constant can be measured, for example, by a cavity resonance method. In this embodiment, the dielectric constant refers to the dielectric constant at a frequency of 1 GHz unless otherwise specified.

[Method of manufacturing glass cloth]
The method for producing the glass cloth of the present embodiment is not particularly limited as long as it includes a step of weaving the above glass yarn as a weft. The above glass yarn may be woven as a weft and a warp. Specifically, the method includes a yarn width adjustment step of adjusting the weft so that 98.0% or more of the yarn width distribution in the length direction of the glass yarn is 220 μm or less, a weaving step of weaving the glass yarn to obtain a glass cloth, and a fiber opening step of opening the glass yarn of the glass cloth. In addition, the method for producing the glass cloth may include a desizing step of removing the sizing agent attached to the glass yarn of the glass cloth and a surface treatment step with a silane coupling agent, as necessary. Each step of the present embodiment will be described in more detail below.

[Glass yarn adjustment process]
The glass thread adjustment process is a process of adjusting the weft thread used so that the average thread width is 95 μm or more and 130 μm or less, and 98.0% or more is 220 μm or less in the thread width distribution in the length direction. More specifically, in the thread width adjustment process, if the weft thread is within the above range in the thread width distribution in the length direction, the thread is used in the subsequent weaving process, and if it is outside the range, the thread is discarded and the glass thread itself is replaced, or the glass thread is adjusted to be within the above range by rewinding or the like. Alternatively, it is possible to provide feedback to the glass thread manufacturing process and adjust the thread manufacturing conditions. Since the wide thread width of the glass thread is likely to occur in a portion where the tension acts locally weakly when the glass thread is wound or in a portion where the twist density is low, there is a possibility that the thread width distribution of the glass thread to be used in the weaving process can be adjusted by rewinding the glass thread or the like. When it is difficult to adjust by rewinding the glass thread or the like, or from the viewpoint of production efficiency, the glass thread itself can also be replaced.

[Weaving process]
The weaving process is a process of weaving glass yarns to obtain glass cloth. The weaving method is not particularly limited as long as it is a method of weaving warp and weft yarns to obtain a predetermined weaving structure. The weaving structure of the glass cloth is not particularly limited, but examples thereof include plain weave, sash weave, satin weave, twill weave, etc. Among these, the plain weave structure is more preferable.

In one aspect of the weaving process in the manufacturing method of this embodiment, the air jet loom method is used to open the warp threads drawn in parallel at the top and bottom, and weaving can be performed by passing the weft threads fed from the weft storage device through the openings using a nozzle jet flow.

In this weaving process, during the glass yarn ejection process in which the glass yarn that will become the weft is unwound from a bobbin and ejected through a storage device, the glass yarn is transported while interfering with loom components such as yarn guides, while moving in a direction different from the direction of travel, such as ballooning, or while interfering with loom components such as yarn guides, while the tension fluctuates as the weft yarn is repeatedly ejected and stopped in units of the length of a single weft yarn. Therefore, it is difficult to minimize the above interference with weft yarns that have wide yarn widths, and the resulting glass cloth may have fuzz or weaving defects.

In contrast, in this embodiment, by using weft yarns in which 98.0% or more of the yarn width distribution in the length direction is 220 μm or less through the above-mentioned yarn width adjustment process, the occurrence of fuzz or weaving defects is suppressed when the weft yarns are woven. This makes it possible to improve the in-plane uniformity and lot-to-lot uniformity of the quality of the glass cloth. Note that the weaving method is not limited to the air jet loom method, and may be a water jet loom method or a shuttle method.

The weaving density of the warp and weft threads that make up the glass cloth is preferably 30 to 90 threads/inch, more preferably 40 to 80 threads/inch, and even more preferably 50 to 75 threads/inch. The weaving density of the warp threads can be controlled by adjusting the spacing between the warp threads drawn in parallel, and the weft thread weaving density can be controlled by the number of times the weft threads are sprayed from the nozzle per unit time and the flow speed of the warp threads. Note that since 1 inch is 25.4 mm, the weaving density per inch can be converted to a weaving density on the order of millimeters.

The thickness of the glass cloth finally obtained after the fiber opening process and the like is preferably 20 to 40 μm, more preferably 22 to 38 μm, and even more preferably 24 to 34 μm. By having the thickness of the glass cloth within the above range, a thin glass cloth that is relatively strong tends to be obtained.

The fabric weight (basis weight) of the glass cloth is preferably 14 to 40 g/ ^m2 , more preferably 16 to 34 g/ ^m2 , further preferably 18 to 32 g/ ^m2 , and particularly preferably 20 to 30 g/ ^m2 .

[Opening process]
The opening step is a step of opening the glass yarns of the glass cloth. The opening method is not particularly limited, but examples thereof include opening processing methods using spray water (high pressure water opening), a vibro washer, ultrasonic water, a mangle, etc.

[Desizing process]
The desizing step is a step of removing the sizing agent attached to the glass yarn of the glass cloth. The desizing method is not particularly limited, but may be, for example, a method of removing the sizing agent by heating.

[Surface treatment process]
The surface treatment step is a step of performing surface treatment of the glass cloth with a silane coupling agent. In addition, examples of the surface treatment method include a method of contacting a surface treatment agent containing a silane coupling agent with the glass cloth and drying it. In addition, examples of the contact of the surface treatment agent with the glass cloth include a method of permeating the glass cloth into the surface treatment agent, and a method of applying the surface treatment agent to the glass cloth using a roll coater, a die coater, a gravure coater, or the like. The method of drying the surface treatment agent is not particularly limited, and examples thereof include hot air drying and a drying method using electromagnetic waves.

(surface treatment)
The glass cloth may be surface-treated with a surface treatment agent. The surface treatment agent is not particularly limited, but may be, for example, a silane coupling agent, and may be used in combination with water, an organic solvent, an acid, a dye, a pigment, a surfactant, or the like, as necessary.

The silane coupling agent is not particularly limited, but examples thereof include a silane coupling agent represented by the following formula (1):
X(R) _{3- nSiYn} ... (1)
(In formula (1), X is an organic functional group having at least one of an amino group and an unsaturated double bond group, each Y is independently an alkoxy group, n is an integer of 1 to 3, and each R is independently a group selected from the group consisting of a methyl group, an ethyl group, and a phenyl group.)
In formula (1), X is preferably an organic functional group having at least three or more of amino groups and unsaturated double bond groups, and more preferably an organic functional group having at least four or more of amino groups and unsaturated double bond groups.

The alkoxy group in the above formula (1) can be in any form, but from the viewpoint of stabilizing the treatment of the glass cloth, an alkoxy group having 5 or less carbon atoms is preferred.

Specific examples of silane coupling agents include N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane and its hydrochloride, N-β-(N-vinylbenzylaminoethyl)-γ-aminopropylmethyldimethoxysilane and its hydrochloride, N-β-(N-di(vinylbenzyl)aminoethyl)-γ-aminopropyltrimethoxysilane and its hydrochloride, N-β-(N-di(vinylbenzyl)aminoethyl)-N-γ-(N-vinylbenzyl)-γ-aminopropyltrimethoxysilane and its hydrochloride, N-β Examples of known simple substances, such as -(N-benzylaminoethyl)-γ-aminopropyltrimethoxysilane and its hydrochloride, N-β-(N-benzylaminoethyl)-γ-aminopropyltriethoxysilane and its hydrochloride, γ-(2-aminoethyl)aminopropyltrimethoxysilane, γ-(2-aminoethyl)aminopropyltriethoxysilane, aminopropyltrimethoxysilane, vinyltrimethoxysilane, methacryloxypropyltrimethoxysilane, and acryloxypropyltrimethoxysilane, or mixtures thereof, are included.

The molecular weight of the silane coupling agent is preferably 100 to 600, more preferably 150 to 500, and even more preferably 200 to 450. Among these, it is preferable to use two or more types of silane coupling agents with different molecular weights. By treating the surface of the glass yarn with two or more types of silane coupling agents with different molecular weights, the density of the surface treatment agent on the surface of the glass cloth tends to increase, and the reactivity with the matrix resin tends to be further improved.

〔Glass cloth〕
The glass cloth of the present embodiment is a glass cloth containing the above-mentioned glass yarn as a weft. In another embodiment, the glass cloth may contain the above-mentioned glass yarn as a weft and a warp. The method for producing the glass cloth is not particularly limited, but may be the one obtained by the above-mentioned production method, and has at least a step of weaving the above-mentioned glass yarn as a weft.

(Dielectric constant of glass cloth)
The dielectric constant of the obtained glass cloth is preferably 5.0 or less, more preferably 4.9 or less, even more preferably 4.8 or less, and particularly preferably 4.6 or less at a frequency of 1 GHz. The dielectric constant can be measured, for example, by a cavity resonance method. In this embodiment, the dielectric constant refers to the dielectric constant at a frequency of 1 GHz unless otherwise specified.

[Prepreg]
The prepreg of this embodiment has the glass cloth obtained as described above and the matrix resin composition impregnated into the glass cloth. The prepreg having the glass cloth has little variation in quality and high yield of the final product. In addition, the prepreg has excellent dielectric properties and excellent moisture absorption resistance, so that it is possible to provide a printed wiring board with little variation in dielectric constant due to the influence of the usage environment, especially in a high humidity environment.

The prepreg of this embodiment can be manufactured according to a conventional method. For example, the prepreg can be manufactured by impregnating the glass cloth of this embodiment with a varnish in which a matrix resin such as an epoxy resin is diluted with an organic solvent, volatilizing the organic solvent in a drying oven, and curing the thermosetting resin to a B-stage state (semi-cured state).

In addition to the above-mentioned epoxy resins, examples of the matrix resin composition include thermosetting resins such as bismaleimide resins, cyanate ester resins, unsaturated polyester resins, polyimide resins, BT resins, and functionalized polyphenylene ether resins; thermoplastic resins such as polyphenylene ether resins, polyetherimide resins, liquid crystal polymers (LCPs) of wholly aromatic polyesters, polybutadiene, and fluororesins; and mixed resins thereof. From the viewpoint of improving the dielectric properties, heat resistance, solvent resistance, and press moldability, the matrix resin composition may be a resin obtained by modifying a thermoplastic resin with a thermosetting resin.

The matrix resin composition may also contain inorganic fillers such as silica and aluminum hydroxide; flame retardants such as bromine-based, phosphorus-based, and metal hydroxide; other silane coupling agents; heat stabilizers; antistatic agents; ultraviolet absorbers; pigments; colorants; lubricants, etc.

[Printed Wiring Board]
The printed wiring board of this embodiment includes the prepreg. The printed wiring board including the prepreg of this embodiment has less variation in quality and a high yield of the final product. In addition, since the prepreg has excellent dielectric properties and excellent moisture absorption resistance, it has the effect of being less susceptible to the influence of the usage environment, particularly in a high humidity environment, and thus has little variation in the dielectric constant.

The present invention will be described in more detail below using examples and comparative examples. The present invention is not limited in any way by the following examples.

[Physical properties of glass yarn and glass cloth]
The physical properties of the glass yarn and the glass cloth, specifically, the thickness of the glass cloth, the diameter or average diameter of the filaments constituting the glass yarn, the number of filaments, the breaking strength (tensile strength) of the glass yarn, and the weaving density (weaving density) of the warp yarn and the weft yarn were measured in accordance with JIS R3420.

[Elastic modulus]
The elastic modulus of the glass filament was measured by the pulse-echo overlap method using a glass bulk obtained by melting and cooling the glass filament as a test piece.

[Glass yarn composition]
The composition of the glass yarn was measured by ICP emission spectrometry. Specifically, the Si content and the B content were measured as follows.
The weighed glass cloth sample was decomposed under pressure with sodium hydroxide, dissolved in dilute nitric acid, and filtered. The insoluble portion was melted with sodium carbonate, dissolved in dilute nitric acid, and mixed with the filtrate to obtain a constant volume. The obtained sample was measured by ICP emission spectrometry to obtain the Si content and B content in terms of _{SiO2 and B2O3} , respectively.

The Al content, Ca content, Mg content, and P content were measured as follows. The weighed glass cloth sample was decomposed by heating with perchloric acid, sulfuric acid, nitric acid, and hydrogen fluoride, then dissolved by heating with dilute aqua regia, and filtered. The filtrate was made to a constant volume. The insoluble matter was decomposed by heating with sulfuric acid, nitric acid, hydrochloric acid, and hydrogen fluoride, then dissolved by heating with dilute aqua regia, and made to a constant volume. These solutions were measured by ICP atomic emission spectrometry to determine the content in the sample, and converted into the oxide value corresponding to the target metal element. The ICP atomic emission spectrometry device used was PS3520VDD II manufactured by Hitachi High-Tech Science Corporation.

[Measurement of yarn width distribution]
While conveying the glass yarn at a speed of 1 m/min, the yarn width of 50 m of the glass yarn was measured using an LED projection type transmission type dimension measuring instrument (HIGH ACCURACY CMOS MICROMETER LS-9006MR / manufactured by Keyence Corporation), and the standard deviation of the yarn width of the glass yarn (yarn width standard deviation A) and the average value of the yarn width were calculated from the obtained yarn width data.

Yarn width measurements using a LED projection type transmissive dimension measuring instrument were performed under conditions that would obtain 1,934 measurement values per meter. If an error occurred due to LED focus issues or other reasons (a value of -9999 was displayed), the measurement was deleted and the average yarn width and/or yarn width distribution was calculated.

The tension acting on the glass yarn as it was being transported was 0.12 to 0.18 N, as measured with a tension meter (Control instruments ETPB-100-C0585, manufactured by SCHMIDT).

[Evaluation 1: Weaving property (short pick)]
In the weaving process using the air jet loom in the Examples and Comparative Examples, the number of times that weaving was stopped during the weaving of 2100 m of glass cloth was counted, and the weaving properties were evaluated according to the following evaluation criteria.
5: 0 stops.
4: Stop 1 to 2 times.
3: Stop 3 to 4 times.
2: Stop 5 to 7 times.
1: 8 or more stops.

[Evaluation 2: Cloth quality (coarse fluff)]
From the glass cloth rolls obtained in the Examples and Comparative Examples, 2000 m of glass cloth was unwound, and the presence or absence of fluff and weaving defects was checked, and the quality was evaluated according to the following evaluation criteria.
5: No coarse fuzz measuring 1 mm or more was observed.
4: One or two coarse fibers measuring 1 mm or more were found,
No coarse fuzz measuring 2 mm or more was observed.
3: 3 to 7 coarse fuzz pieces measuring 2 mm or more were observed.
2: 8 or more but less than 30 coarse fuzz pieces measuring 2 mm or more were found.
1: 30 or more coarse fibers measuring 2 mm or more were found.

[Evaluation 3: Electrical characteristics (dielectric tangent) of evaluation board]
Using the glass cloths obtained in the Examples and Comparative Examples, evaluation test pieces for measuring electrical properties were prepared under the following conditions, and the dielectric loss tangents were measured.

The glass cloth obtained in the examples and comparative examples was continuously drawn out and conveyed while impregnating the glass cloth with varnish, passing it through a slit to adjust the amount of varnish applied, and then passing it through a drying oven at 120°C to dry it and obtain a prepreg. The varnish used contained 65 parts by mass of methacrylated polyphenylene ether, 35 parts by mass of triallyl isocyanurate, 10 parts by mass of hydrogenated styrene-based thermoplastic elastomer, 25 parts by mass of bromine-based flame retardant, 65 parts by mass of spherical silica, 1 part by mass of organic peroxide, and 210 parts by mass of toluene, and was adjusted so that the resin content was 73% by mass.

A predetermined number of the obtained prepregs were stacked, and copper foil (GTS-MP foil, 18 μm thick, manufactured by Furukawa Electric Co., Ltd.) was placed on both sides of the stacked prepregs, and the resulting laminate was vacuum pressed to obtain a copper-clad laminate. Next, the copper foil was removed from the copper-clad laminate by etching to obtain a laminate.

A test piece having a length of about 50 mm and a width of about 1.5 mm was cut out from the obtained laminate so that the warp yarns of the glass cloth were the long side, and placed in an oven at 105°C ± 2°C and dried for 2 hours. Then, the dielectric loss tangent at 10 GHz was measured under the conditions shown below.
Standard conditions: The test piece is left to stand in a constant temperature room at 23±2° C. and a relative humidity of 50±5% for 96 hours, and then the measurement is performed.

The measurement was performed using a network analyzer (N5230A, manufactured by Agilent Technologies) and a cavity resonator (Cavity Resonator CP series) manufactured by Kanto Electronics Application Development Co., Ltd., in an environment of 23±2°C and relative humidity of 50±5%. Each measurement was performed on five cut-out test pieces, and the average value was taken as the dielectric tangent value.

[Examples 1 to 7, Comparative Examples 1 to 3, Reference Examples 1 and 2]
<Weaving test>
Glass yarns having the composition shown in Table 1 (average diameter of glass filaments: 5.0 μm, number of filaments: 100) were used as warp and weft yarns and woven in an air jet loom to obtain a glass cloth greige machine having a warp weaving density of 65/25 mm, a weft weaving density of 67/25 mm, and a thickness of 30 μm. Next, a desizing treatment was performed by heating, and a fiber opening process was performed with a high-pressure water spray, followed by a surface treatment using a silane coupling agent to produce a glass cloth.

The breaking strength of the glass yarn used in the weaving test, the weaving evaluation results during weaving, the glass cloth quality, and the electrical properties are shown in Tables 1 to 3.

Examples 1 to 7 produced glass cloths with excellent weaving properties and cloth quality. Among them, Examples 1, 2, 5, and 7, which have few wide weft yarns, produced the most excellent glass cloth quality.

In Example 6, there were few areas with a wide yarn width, but there was a tendency for a slightly larger amount of coarse fuzz to be generated, possibly due to the larger elastic modulus compared to Examples 1, 2, and 5.

In Example 7, a glass yarn with many wide areas was used for the warp thread, but a glass yarn with few wide areas was used for the weft thread, resulting in a good glass cloth.

In contrast, Examples 3 and 4, which had a slightly higher proportion of wide yarn width areas, had good weaving properties but tended to produce a slightly higher amount of coarse fuzz.

The glass cloths produced in Comparative Examples 1 and 2 had good flying properties because the glass yarns had many areas with a wide yarn width, but they produced a lot of coarse fuzz and were of poor quality.

The glass cloth produced in Comparative Example 3 had poor weaving properties due to the overall narrow width of the glass yarn, which resulted in insufficient flight properties and many short picks.

Reference Examples 1 and 2 show the production of glass cloth using conventional E-glass yarn. A glass cloth with excellent weaving properties and quality was obtained, but its electrical properties were inferior to those of the glass cloths of Examples 1 to 7.

Claims (17)

A yarn width adjusting step of adjusting the yarn width distribution of the glass yarn to a range in which the average yarn width is 95 μm or more and 130 μm or less and 98.0% or more is 220 μm or less when the average yarn width is outside the range of 95 μm or more and 130 μm or less and 98.0% or more is 220 μm or less in the yarn width distribution in the length direction of the glass yarn; and
The glass yarn is
The glass filaments having an average diameter of 4.5 μm or more and 5.5 μm or less are bundled together in a number of 92 to 108 pieces ,
The density is 2.2 g/ ^cm3 or more and less than 2.5 g/ ^cm3 ,
The breaking strength is 0.50 N/tex or more and 0.80 N/tex or less,
The average yarn width when measured over 50 m is 95 μm or more and 125 μm or less,
a step of weaving a fabric using the glass yarn as a weft , the weaving being such that 98.0% or more of the fabric in the length direction has a yarn width of 220 μm or less when measured over 50 m ;
A method for producing a glass cloth comprising the steps of: 2. The method for producing a glass cloth according to claim 1 , wherein, when 50 m of the glass yarn is measured, 95.0% or more of the glass yarn in the length direction has a yarn width of 190 μm or less. The glass yarn is
The silicon (Si) content is SiO ₂ 40 to 60 mass% in terms of mass conversion, and
The boron (B) content is B ₂ O ₃ Converted to 15 to 40% by mass.
The method for producing the glass cloth according to claim 1 or 2. The B content is ₂ O ₃ The method for producing glass cloth according to claim 3, wherein the content of the polyvinyl chloride in the glass fiber is 20 to 40 mass % in terms of the total mass of the glass fiber. The method for producing a glass cloth according to any one of claims 1 to 4, wherein the glass yarn has an elastic modulus of 50 GPa or more and 70 Pa or less. The method for producing a glass cloth according to claim 5, wherein the elastic modulus is 50 GPa or more and 63 GPa or less. The method for producing a glass cloth according to any one of claims 1 to 6, wherein the glass yarn has a dielectric constant of 5.0 or less at a frequency of 1 GHz. The method for producing a glass cloth according to any one of claims 1 to 7, wherein the glass cloth has a dielectric constant of 5.0 or less at a frequency of 1 GHz. The method for producing a glass cloth according to any one of claims 1 to 8, wherein in the yarn width adjustment step, the glass yarn itself is replaced or the glass yarn is rewound. A method for producing a glass yarn in which 92 to 108 glass filaments having an average diameter of 4.5 μm to 5.5 μm are bundled together, the method comprising the steps of:
When the average width of the glass yarn is outside the range of 95 μm or more and 130 μm or less and 98.0% or more is 220 μm or less in the yarn width distribution in the length direction of the glass yarn, the yarn width distribution of the glass yarn is adjusted to be within the range of 95 μm or more and 130 μm or less and 98.0% or more is 220 μm or less,
The glass yarn comprises:
The density is 2.2 g/ ^cm3 or more and less than 2.5 g/ ^cm3 ,
The breaking strength is 0.50 N/tex or more and 0.80 N/tex or less,
The average yarn width when measured over 50 m is 95 μm or more and 125 μm or less, and when measured over 50 m, 98.0% or more of the yarn in the length direction has a yarn width of 220 μm or less.
A method for manufacturing glass yarn. The method for producing a glass yarn according to claim 10 , wherein, when 50 m of the glass yarn is measured, 95.0% or more of the length of the glass yarn has a yarn width of 190 μm or less. The glass yarn is
The silicon (Si) content is SiO ₂ 40 to 60 mass% in terms of mass conversion, and
The boron (B) content is B ₂ O ₃ Converted to 15 to 40% by mass.
The method for producing a glass filament according to claim 10 or 11. The B content is ₂ O ₃ The method for producing a glass yarn according to claim 12, wherein the content is 20 to 40 mass% in terms of the total mass of the glass yarn. The method for producing a glass yarn according to any one of claims 10 to 13, wherein the glass yarn has an elastic modulus of 50 GPa or more and 70 Pa or less. The method for producing a glass filament according to claim 14, wherein the elastic modulus is 50 GPa or more and 63 GPa or less. The method for producing a glass yarn according to any one of claims 10 to 15, wherein the glass yarn has a dielectric constant of 5.0 or less at a frequency of 1 GHz. The method for producing a glass yarn according to any one of claims 10 to 16, wherein in the yarn width adjustment step, the glass yarn itself is replaced or the glass yarn is rewound.