CN115404584B - Glass yarn, glass cloth manufacturing method and glass cloth - Google Patents

Abstract

The purpose of the present invention is to provide a method for manufacturing glass yarn and glass cloth, and to provide a glass cloth with few defects, a method for manufacturing the same, and a glass yarn constituting the same. A glass cloth is obtained by weaving a glass yarn containing a plurality of glass filaments as warp and weft. 500 m in the length direction of the glass cloth is taken as the object, and white LED light is irradiated along the cloth surface. Every 1 m in the length direction is observed. When the number of defects is counted as 1 in the case of the existence of fluff on the entire surface of the above-mentioned cloth surface, the deduction rate expressed by the following formula is 0 to 3.5%. Deduction rate (%) = (total number of defects/500) × 100.

Description

Glass yarn, method for producing glass cloth, and glass cloth

Technical Field

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

Background

With the recent development of information communication society, data communication and/or signal processing is being performed at a high speed with a large capacity. As a result of using a printed circuit board in a high-end server, a high-end router/switch, a supercomputer, a communication device of a base station, a meter, and the like, the dielectric constant of the printed circuit board is being reduced. Accordingly, as for glass cloths constituting printed circuit boards, low dielectric glass cloths have been proposed. For example, patent document 1 discloses that, in a conventionally used E-glass cloth, a large amount of diboron trioxide (B ₂O₃) is mixed with a glass composition, and the mixing amount of other components such as silica (SiO ₂) is adjusted, thereby realizing low dielectric characteristics of the glass cloth.

In recent years, it has been expected that a printed circuit board used for a smart phone application will have a lower dielectric power because of the demand for high-capacity and high-speed communication in a terminal electronic device such as a smart phone. Therefore, there is a strong demand for thin (e.g., 10 to 50 μm thick) low dielectric glass cloths.

Prior art literature

Patent literature

Patent document 1 Japanese patent laid-open No. 11-292567

Patent document 2 Japanese patent application laid-open No. 2013-112917

Patent document 3 Japanese patent application laid-open No. 2004-115351

Patent document 4 Japanese patent application laid-open No. 2011-140721

Patent document 5 International publication No. 2018/216637

Disclosure of Invention

Problems to be solved by the invention

The inventors of the present invention have found that the low dielectric glass cloth described in patent document 1 has a variation in performance and quality as compared with the conventional known E glass cloth. In particular, in a low dielectric glass cloth having a thickness of 10 to 50 μm, a large variation in fluff quality tends to occur, and therefore, it is difficult to stably obtain a glass cloth excellent in fluff quality.

As a method for improving the fluff quality of glass cloth, patent documents 2 and 3 disclose a method in which a specific starch is used as a bundling agent for glass yarns, patent document 4 discloses a method in which bending of yarns in bead rings is alleviated during production of glass yarns, and patent document 5 discloses a method in which a specific composition is used for low dielectric glass.

Patent document 2 discloses that fuzzing of a cloth can be suppressed by producing a glass cloth using glass yarns produced using a sizing agent containing 25 to 100 mass% of starch composed of amylose, and having an average particle diameter of 12 μm or less.

Patent document 3 discloses that the bundling property of glass yarns is improved by producing glass yarns to which 1.5 to 3.0 mass% of a bundling agent containing etherified high amylose starch having an amylose content of 50% or more is attached, whereby fluff can be effectively prevented from occurring.

Patent document 4 discloses that in the yarn twisting step of manufacturing glass yarns, the yarn passing portion of the bead ring is thickened to alleviate the bending of the yarn when passing the bead ring, and quality defects such as fluff, yarn breakage, and knot are less likely to occur.

Patent document 5 discloses a low dielectric glass containing, in terms of weight%, 50 to 20% of SiO ₂≤56、20≤B₂O₃≤30、10≤Al₂O₃, 3.5 to 10% of MgO+CaO, and 0 to 1.0 of R ₂ O (wherein R is at least 1 element selected from Li, na, and K) and further containing Fe ₂O₃, whereby yarn breakage and fuzzing during glass yarn processing can be suppressed.

It is assumed that the low dielectric glass yarn has a strength lower than that of the glass yarn of the E glass used in the past, and that the quality of the nap of the glass cloth produced by using the low dielectric glass yarn which can be obtained in the market is greatly deviated, and therefore, the low dielectric glass yarn of the glass cloth having a high quality has not been obtained stably so far.

For example, by using glass yarns having few defects, improvement in quality of glass cloth is easily achieved. In recent years, in the context of quality improvement required for glass cloths, it is desired to provide glass cloths that can satisfy the expectations for such quality improvement. As an example, low dielectric resins tend to have a high molecular weight or a high volume functional group, and thus, there is a background that a high impregnation property is required for the glass cloth side because the impregnation property of varnish is inferior to that of conventional resins.

The present invention has been made in view of the above-described problems, and an object thereof is to provide a glass yarn having few drawbacks, a glass cloth having high uniformity and good quality using the glass yarn, and a method for producing the glass cloth.

Solution for solving the problem

The present inventors have made intensive studies to solve the above problems, and as a result, have focused on the fact that fine fluff and the like can be detected first by a predetermined visual observation, and have completed the present invention. One mode of the present invention is as follows.

[1] A glass cloth obtained by weaving a glass yarn comprising a plurality of glass filaments with warp yarns and weft yarns,

When the number of defects counted when the entire cloth surface is 1 is observed for every 1m in the longitudinal direction by irradiating the cloth surface with white LED light along 500m in the longitudinal direction of the glass cloth, the percentage of the cut-out represented by the following formula is 0 to 3.5%.

The deduction rate (%) = (total of statistics of defects/500) ×100

[2] The glass cloth according to item 1, wherein the entire pile includes 200 to 1000 μm of fuzzing caused by breakage of the filaments observed on the cloth cover by an optical microscope.

[3] The glass cloth according to item 1 or 2, wherein the glass cloth has a thickness of 10 to 50 μm.

[4] The glass cloth according to any one of items 1 to 3, comprising the glass yarn satisfying the following condition:

(i) TEX is 1-13;

(ii) The breaking strength is 0.50-0.80N/tex, and

(Iii) The number of filaments which slipped to 2 times or more of the average yarn width at 180m was measured was 3 or less.

[5] The glass cloth according to any one of items 1 to 4, which comprises the glass yarn having a twist interval length of 1.8 to 10.0 cm.

[6] The glass cloth according to any one of items 1 to 5, which comprises the glass yarn having a value (twist interval length difference index) of 0.7 or less, which is obtained by dividing a difference between a maximum value of the twist interval length and a minimum value of the twist interval length of the glass yarn by an average value of the twist interval lengths.

[7] The glass cloth according to any of items 1 to 6, wherein,

The glass yarn having a length of 10,000m or more is targeted,

When measuring ranges of 180m in the longitudinal direction are selected at 5 different positions, the number of filaments slipping to 2 times or more of the average value of the yarn width is 3 or less in the measuring ranges at 5 positions.

[8] The glass cloth according to any of items 1 to 6, wherein,

The glass yarn having a length of 50,000m or more is targeted,

When measuring ranges of 180m in the longitudinal direction are selected at 7 different positions, the number of filaments slipping to 2 times or more of the average value of the yarn width is 3 or less at the measuring ranges at 7 positions.

[9] The glass cloth according to any of items 1 to 6, wherein,

The glass yarn having a length of 100,000m or more is targeted,

When measuring ranges of 180m in the longitudinal direction are selected respectively at 10 different positions, the number of filaments slipping to 2 times or more of the average value of the yarn width is 3 or less in the measuring ranges at 10 positions.

[10] A method for producing a glass cloth, comprising a step of weaving a glass yarn comprising a plurality of glass filaments by using warp yarns and weft yarns,

(I) The TEX of the glass yarn is 1-13;

(ii) The breaking strength of the glass yarn is 0.50-0.80N/tex, and

(Iii) The number of filaments which slipped to 2 times or more of the average yarn width at 180m was measured was 3 or less.

[11] The method for producing a glass cloth according to item 10, wherein the glass yarn has a TEX of 1 to 7.

[12] The method for producing a glass cloth according to item 10 or 11, wherein the glass yarn has 30 to 120 glass filaments.

[13] The method for producing a glass cloth according to any one of items 10 to 12, wherein the glass yarn has a twist interval length of 1.8 to 10.0cm.

[14] The method for producing a glass cloth according to any one of items 10 to 13, wherein a difference between a maximum value of the twist interval length and a minimum value of the twist interval length of the glass yarn divided by an average value of the twist interval lengths (twist interval length difference index) is 0.7 or less.

[15] The method for producing a glass cloth according to any one of items 10 to 14, wherein the glass yarn has a density of 2.2g/cm ³ or more and less than 2.5g/cm ³.

[16] The method for producing a glass cloth according to any one of items 10 to 15, wherein the elastic modulus of the glass yarn is 50 to 70GPa.

[17] The method for producing a glass cloth according to any one of items 10 to 16, wherein the elastic modulus of the glass yarn is 50 to 63GPa.

[18] The method for producing a glass cloth according to any one of items 10 to 17, wherein,

The glass yarn having a length of 10,000m or more is targeted,

When measuring ranges of 180m in the longitudinal direction are selected at 5 different positions, the number of filaments slipping to 2 times or more of the average value of the yarn width is 3 or less in the measuring ranges at 5 positions.

[19] The method for producing a glass cloth according to any one of items 10 to 17, wherein,

The glass yarn having a length of 50,000m or more is targeted,

When measuring ranges of 180m in the longitudinal direction are selected at 7 different positions, the number of filaments slipping to 2 times or more of the average value of the yarn width is 3 or less at the measuring ranges at 7 positions.

[20] The method for producing a glass cloth according to any one of items 10 to 17, wherein,

The glass yarn having a length of 100,000m or more is targeted,

When measuring ranges of 180m in the longitudinal direction are selected respectively at 10 different positions, the number of filaments slipping to 2 times or more of the average value of the yarn width is 3 or less in the measuring ranges at 10 positions.

[21] A glass yarn, wherein,

(I) TEX is 1-13;

(ii) The breaking strength is 0.50-0.80N/tex, and

(Iii) The number of filaments which slipped to 2 times or more of the average yarn width at 180m was measured was 3 or less.

[22] The glass yarn of item 21, wherein the TEX is 1-7.

[23] The glass yarn according to item 21 or 22, wherein the number of glass filaments constituting the glass yarn is 30 to 120.

[24] The glass yarn of any of items 21 to 23, wherein the twist interval length is 1.8 to 10.0cm.

[25] The glass yarn according to any one of items 21 to 24, wherein a value obtained by dividing a difference between a maximum value of the twist interval length and a minimum value of the twist interval length by an average value of the twist interval lengths (twist interval length difference index) is 0.7 or less.

[26] The glass yarn of any of items 21 to 25, having a density of 2.2g/cm ³ or more and less than 2.5g/cm ³.

[27] The glass yarn of any one of items 21 to 26, which has an elastic modulus of 50 to 70GPa.

[28] The glass yarn of any one of items 21 to 27, which has an elastic modulus of 50 to 63GPa.

[29] The glass yarn as in any of items 21-28, wherein,

The glass yarn having a length of 10,000m or more is targeted,

When measuring ranges of 180m in the longitudinal direction are selected at 5 different positions, the number of filaments slipping to 2 times or more of the average value of the yarn width is 3 or less in the measuring ranges at 5 positions.

[30] The glass yarn as in any of items 21-28, wherein,

The glass yarn having a length of 50,000m or more is targeted,

When measuring ranges of 180m in the longitudinal direction are selected at 7 different positions, the number of filaments slipping to 2 times or more of the average value of the yarn width is 3 or less at the measuring ranges at 7 positions.

[31] The glass yarn as in any of items 21-28, wherein,

The glass yarn having a length of 100,000m or more is targeted,

When measuring ranges of 180m in the longitudinal direction are selected respectively at 10 different positions, the number of filaments slipping to 2 times or more of the average value of the yarn width is 3 or less in the measuring ranges at 10 positions.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, there can be provided a glass yarn having few defects, and a glass cloth having high uniformity and good quality can be provided by using the glass yarn, and further, a method for producing the glass cloth can be provided.

Detailed Description

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

[ Glass cloth ]

A first embodiment of the present invention is a glass cloth.

The glass cloth of the present embodiment is:

A glass yarn comprising a plurality of glass filaments (hereinafter also simply referred to as "filaments") is woven by using warp yarns and weft yarns, and the white LED light is irradiated along the cloth cover for every 1m of the cloth cover in the longitudinal direction, and when the number of defects in the whole cloth cover is counted to be 1 in the presence of nap of the whole cloth cover, the percentage of the buckle represented by the following formula is 0 to 3.5%.

The deduction rate (%) =total of statistics of whole pile/500 (m) ×100

In this embodiment, by irradiating white LED light along the cloth cover and observing the cloth cover, filament breakage (hereinafter also referred to as "fine fluff") having a length of less than 1mm can be detected with good sensitivity as compared with conventional observation achieved by irradiating light in the vertical direction to the cloth cover. Further, since the deduction rate derived from this detection method is 0 to 3.5%, the glass cloth has few drawbacks and is excellent in various characteristics. From the same point of view, the buckling rate is preferably 3.0% or less, more preferably 2.9% or less.

The conventional observation (conventional observation performed by irradiating the cloth surface with light in the vertical direction) does not contemplate observation of fine naps. Therefore, in the case of using the conventional observation method, it is impossible to detect fine fluff as assumed in the present embodiment with good sensitivity, and further, it is not easy to control the buckling rate to the numerical range as assumed in the present embodiment.

The calculation method of the "percent (%)" is described in detail in examples.

The whole fluff includes 200-1000 μm fluff caused by filament breakage observed on a cloth cover by an optical microscope. As shown in the present embodiment, the white LED light is irradiated along the cloth cover, and the whole fluff is easily observed by observing the cloth cover.

The glass cloth of the present embodiment preferably has a thickness as described later. The glass yarn used to obtain the glass cloth according to the present embodiment preferably has the following structure.

(Dielectric constant of glass cloth)

The dielectric constant of the glass cloth is preferably 5.0 or less, more preferably 4.9 or less, further preferably 4.8 or less, particularly preferably 4.6 or less at a frequency of 10 GHz. The dielectric constant of the glass cloth can be measured by a cavity resonance method. In the present specification, the dielectric constant of the glass cloth means the dielectric constant at a frequency of 10GHz unless otherwise specified.

[ Glass yarn ]

A second embodiment of the present invention is a glass yarn.

With respect to the glass yarn of the second embodiment,

(I) TEX is 1-13;

(ii) The breaking strength is 0.50-0.80N/tex, and

(Iii) The number of filaments which slipped to the average value of the yarn width at 180m was measured and was 2 times or more (hereinafter, the "number of filaments which slipped to the average value of the yarn width at 180m was 2 times or more" simply referred to as "slipped filaments") was 3 or less.

The quality of the glass cloth manufactured by using the low dielectric glass yarn is different from that of the conventional E glass cloth. Therefore, it is known that it is difficult to stably obtain a high-quality low-dielectric glass cloth. In particular, when a glass cloth having a poor quality was studied in detail, in a low dielectric glass cloth produced from a low dielectric glass yarn having a number of slipped filaments deviated from a specific range, it was confirmed that a large amount of fluff was densely present in a longitudinal direction in a ribbon-like shape. In contrast, the present embodiment is based on the insight that the use of a low dielectric glass yarn in which the falling off of filaments falls within a specific range can reduce the drawbacks of the low dielectric glass cloth. While not being bound by theory, it is believed that when glass yarns having a yarn fall-off of more than a specific value (for example, a number of slipped yarns of more than 3) are pulled out from a spool (bobbin) in a weaving process and then passed through a loom member such as a loop guide, the yarn fall-off is likely to be increased or broken when the yarn is subjected to interference with the loom member.

In particular, the weft yarn is carried along with the movement of the balloon (ballooning) in the yarn path until the weft yarn is pulled out from the spool and ejected. Therefore, it is considered that the filament slipping portion is likely to receive a shearing stress to be broken, and the broken filament piece is likely to be entangled by a rotational movement to grow into coarse fluff. For the purpose of improving productivity, the weft yarn is preferably woven in at a higher speed, but it is considered that the higher the weft yarn carrying speed is, the more the filament fall-off or the filament breakage is likely to become larger.

The E glass yarn used up to now has a higher density and a higher strength than the low dielectric glass yarn. Therefore, the glass yarn is also stably transported, and the degree of interference with the loom member is small, so that damage to the loom member caused by the interference is limited. On the other hand, in a low dielectric glass yarn which is lighter and has lower strength, there is a tendency that the variation is increased due to tension fluctuation or the like when the glass yarn is conveyed. Therefore, the interference with the loom member is liable to occur, and even when the interference with the loom member occurs, the loom member is liable to be more damaged. Thus, it is believed that it is easy to promote the aggravation of filament fall-off or filament breakage.

In addition, when the glass yarn having a filament falling off more than a specific range is subjected to a physical load such as high-pressure spray water in the opening step, the falling-off portion is liable to move. Therefore, it is considered that the detached portion is liable to receive a load such as interference with the conveyance member of the glass cloth, and fuzzing of the nap or the broken portion caused by breakage of the filaments is liable to occur with the detached portion as a starting point. In order to improve the in-plane uniformity and impregnation property of the glass cloth, a strong opening force is preferable, but it is considered that the stronger the opening force is, the more fluff defects due to breakage of filaments or coarse fluff defects due to entanglement of filaments are more likely to occur.

Further, the low dielectric glass yarn having a lower density and lower strength than E glass significantly reduces the glass strength in the heat cleaning step. Therefore, it is considered that, when the opening step is performed after the heat cleaning step, the fiber is strongly damaged by physical load such as high-pressure water spray, and fluff due to breakage of filaments or fuzzing of broken filaments is more likely to occur. It is believed that these effects are manifested in the form of the quality of the glass cloth.

On the other hand, by using the glass yarn according to the present embodiment, even when a glass yarn having a low dielectric strength and a low weight is used, damage to the loom member such as a loop guide, which is received when the glass yarn is pulled out and then passed through the loom member, can be reduced. In addition, when the glass yarn according to the present embodiment is used, the degree of interference between the detached portion and the conveying member and the damage received during the interference can be reduced in the fiber opening step. By using the glass yarn according to the present embodiment, generation of fluff due to filament breakage in the weaving step and the opening step can be suppressed, and a glass cloth having good and uniform quality can be obtained. Further, the use of the glass yarn is preferable because the weaving speed (the weaving speed of the glass yarn) and/or the opening processing force in the opening step tend to be improved.

When the glass yarn according to the present embodiment is used, it is preferable to use a creel (creel) because, in a process of pulling out the glass yarn (for example, warp yarn) from the bobbin base yarn and straightening the glass yarn, defects such as fluff can be prevented from occurring when the glass yarn is rubbed by a yarn path guide or the like, and therefore, the quality is good and stable production is possible. In addition, the use of the glass yarn is preferable because it tends to increase the warp speed.

(TEX of glass yarn)

The TEX of the glass yarn is1 to 13, preferably 1.5 to 12, more preferably 2.0 to 11, still more preferably 2.5 to 10 or 1 to 7. If the TEX of the glass yarn is 13 or less, the strength of the glass yarn is low, and thus there is a tendency that the glass yarn interferes with a loom member such as a loop guide when the glass yarn is pulled out in a weaving process and then passes through the loom member, and interferes with a carrying member of a glass cloth in a fiber opening process, whereby fluff is likely to occur. On the other hand, by adjusting the degree of falling of the filaments within the specific range of the present embodiment, the degree of interference or damage received during interference can be reduced, and as a result, a high-quality glass cloth can be stably obtained. When the TEX of the glass yarn is1 or more, it is possible to suppress breakage of the filaments when the glass yarn is pulled out in the weaving step and then passed through a loom member such as a loop guide, or when the glass yarn is interfered with a transport member of the glass cloth in the opening step, when the degree of yarn fall falls within the specific range of the present embodiment.

(Breaking Strength of glass yarn)

The breaking strength of the glass yarn is 0.50-0.80N/tex. The preferable range of breaking strength is 0.53 to 0.79N/tex, more preferable range is 0.57 to 0.78N/tex, and still more preferable range is 0.60 to 0.77N/tex. If the breaking strength of the glass yarn is not less than the lower limit, the filaments are less likely to break and fluff is less likely to occur when the glass yarn interferes with a loom member such as a loop guide after being pulled out in a weaving process and interferes with a carrying member of the glass cloth in a fiber opening process to receive a shearing stress. On the other hand, if the breaking strength of the glass yarn is equal to or lower than the upper limit, yarn deviation and balloon movement during yarn conveyance until the glass yarn is pulled out from the spool and ejected tend to be small, and as a result, the progress of filament fall-off and fluff failure due to filament breakage are less likely to occur. This is presumed to be based on the effect of the ductility of the glass yarn.

(Number of slipped filaments of glass yarn)

The number of the slip filaments of the glass yarn is 3 or less. The number of the slip filaments is preferably 2 or less, more preferably 1 or less, and still more preferably 0.

The above "180m" may be any one of the following lengths:

1) A length having an end (one end or the other end) in the longitudinal direction of the glass yarn as a starting point;

2) The length of any portion other than the end portion.

Specific examples of the above 2) include:

2-1) a length set from a position 2 to 6m (for example, 5 m) from the end in the longitudinal direction as a starting point.

If 2-1) is used, the number of slipped filaments is easily and accurately measured according to the gist of the present invention without being affected by "loose" which is easily generated at the end of the glass yarn.

In the case of a state where the glass yarn is wound onto the spool, "180m" may be any one of the following lengths:

3) A length comprising at least a portion of the outermost circumference or the innermost circumference of the spool;

4) Length of any portion other than the outermost periphery and the innermost periphery.

Specific examples of the above 4) include, from the viewpoint of the ease of observation:

4-1) a length set with a start portion of the second turn at the time of the first turn of the outermost Zhou Wei as a start point;

4-2) a length set with a start portion of the second turn at the time of the first turn at the innermost Zhou Wei as a start point.

Wherein, can be:

4-3) a length set at an arbitrary position other than the above-mentioned starting point.

When a measuring range of 180m in the longitudinal direction is selected for glass yarns having a length of 10,000m or more at 5 points different from each other, the number of slipped filaments is preferably 3 or less, more preferably 2 or less, still more preferably 1 or less, and most preferably 0 in the measuring range of 5 points.

Further, when a measuring range of 180m in the longitudinal direction is selected for glass yarns having a length of 50,000m or more at 7 points different from each other, the number of slipped filaments is preferably 3 or less, more preferably 2 or less, still more preferably 1 or less, and most preferably 0 in the measuring range at 7 points.

Further, when a measurement range of 180m in the longitudinal direction is selected for glass yarns having a length of 100,000m or more at 10 points different from each other, the number of slipped filaments is preferably 3 or less, more preferably 2 or less, still more preferably 1 or less, and most preferably 0 in the measurement range of 10 points.

The conveyance speed of the glass yarn can be increased when the number of the slipped filaments is measured. In order to keep the same as the weft yarn ejection in the weaving process, the glass yarn may be pulled out of the spool by air and measured while being carried (in this case, a yarn path guide is appropriately provided to prevent the ejected glass yarn from being out of control).

The number of slipped filaments was measured by the method described in the examples.

By setting the number of the slipped filaments to be equal to or less than the above range and the breaking strength to be equal to or less than the above range, coarse fluff caused by the progress of the falling-off of the grown filaments, the broken filaments, or the entanglement of the broken filaments is less likely to occur during the conveyance from the pulling-out of the glass yarn from the spool to the ejection. Thus, a high-quality glass cloth with less fluff-dense portions can be stably obtained. It is assumed that this is because the degree and frequency of slippage of the filaments are small within a certain range, and therefore the degree of interference between the slippage and the loom member such as the loop guide or the resistance caused by the interference is small, and therefore damage caused by the interference with the loom member can be suppressed to be small.

In particular, as described above, the weft yarn is easily broken, and furthermore, broken filament pieces are easily entangled by balloon movement. On the other hand, it is presumed that breakage of filaments or entanglement of broken filaments is suppressed by adjusting the number of detached filaments to be within the above range. Further, it is presumed that the degree and frequency of filament slippage are small within a certain range, and therefore the degree of interference with the conveyance member of the glass cloth or the resistance due to the interference becomes small in the opening step, and thus damage due to the interference with the conveyance member can be suppressed to be small.

The number of slipped filaments can be adjusted by the following methods alone or in combination:

In the spinning step of producing glass yarns, when filaments ejected from a plurality of sleeve nozzles (polishing nozzles) are collected into 1 yarn bundle, a sleeve nozzle arrangement method is designed such that distances from the plurality of sleeve nozzles to a collection point are equal;

A method of adjusting the nozzle shape of the sleeve nozzle based on the difference in distance from the sleeve nozzle to the bundling point;

a method of adjusting the temperature of the sleeve nozzle based on the difference in distance from the sleeve nozzle to the bundling point;

A method of adjusting the cooling temperature in the spinning step of producing the glass yarn;

a method of adjusting the cake (cake) take-up tension;

A method of adjusting the take-up speed of the cake;

A method of adjusting the threading distance (transition) at the time of winding the cake;

In the aging step of producing a cake of glass yarn, the cake winding method and the aging condition are adjusted so that the moisture content of the glass yarn and the amount of sizing agent deposited are more uniform over the entire length of the glass yarn;

in the yarn twisting step of manufacturing the glass yarn, the shape and weight of the bead ring are adjusted so that the load when the glass yarn is bent becomes small;

a method of adjusting the fluctuation range of the number of twists per unit length to a specific range;

A method of adjusting the tension fluctuation during the period in which the glass yarn is pulled out from the yarn cake and wound on the spool;

method for adjusting balloon during twisting and

A method of adjusting the winding angle of the glass yarn on the spool.

(Density of glass yarn)

The glass yarn preferably has a density of 2.2g/cm ³ or more and less than 2.5g/cm ³, more preferably 2.2g/cm ³ or more and less than 2.45g/cm ³, still more preferably 2.2g/cm ³ or more and 2.40g/cm ³ or less, still more preferably 2.25g/cm ³ or more and 2.4g/cm ³ or less.

If the density of the glass yarn is less than 2.5g/cm ³, there is a tendency that the deviation in the direction perpendicular to the conveying direction or the balloon movement tends to be large during the conveyance from the time when the glass yarn is pulled out from the spool and ejected, and fluff is likely to be generated by interference with the loom members. However, by adjusting the number of slipping filaments to be within the specific range described in this embodiment, generation of fluff due to interference with the loom members is suppressed, and thus, a high-quality glass cloth can be stably obtained.

If the glass yarn density is less than 2.5g/cm ³, there is a tendency that the glass cloth tends to be loose and easily interfere with the carrying member and the lint Mao Buliang tends to be generated by the interference with the carrying member when a physical load such as high-pressure water spray pressure is applied during the opening step. However, by adjusting the number of slipping filaments to be within the specific range in the present embodiment, generation of fluff due to interference with the conveyance member is suppressed, and thus, a high-quality glass cloth can be stably obtained.

On the other hand, by setting the density of the glass yarn to 2.2g/cm ³ or more, the conveyance track of the glass yarn can be kept stable. Further, by setting the density of the glass yarn to 2.2g/cm ³ or more, the relaxation of the glass cloth can be reduced. The density of the glass yarn can be determined as the density of 1cm ³ of bulk glass.

(Filament and diameter)

Glass yarns are obtained by bundling a plurality of filaments and twisting the filaments as necessary. In this case, the glass yarn is classified as glass multifilament, and filaments (glass filaments) contained in the glass yarn are classified as glass monofilament, respectively.

The "slipping" of the filaments herein means not only slipping of the glass filaments in units of 1 filament, slipping of the glass filaments in units of several filaments, but also breaking of the filaments. The number of slipped filaments was measured by the method described in the examples.

The glass yarn is preferably a glass yarn obtained by bundling 40 to 240 glass filaments having an average diameter of 3.5 to 5.5 μm or a glass yarn having 30 to 120 glass filaments. Glass yarns having average diameters and filament numbers in the above-described ranges are used, whereby glass cloths (IPC standard (IPC-4412B): style1000, 1017, 1015, 1012, 1027, 1024, 1020, 1035, 106, 1067, 1078) having thicknesses equivalent to those of conventional E glass cloths are easily produced.

(Modulus of elasticity of glass yarn)

The elastic modulus of the glass yarn is preferably 50 to 70GPa, more preferably 50 to 63GPa, and even more preferably 53 to 63GPa. When the elastic modulus is 50GPa or more, the rigidity of the glass yarn is improved, and fluff is less likely to be generated in the manufacturing process. Further, when the modulus of elasticity is 70GPa or less, the glass yarn tends to be improved in brittleness resistance and less prone to fluff during the production process. Further, when the elastic modulus is in the above range, the glass yarn tends to have flexibility, and when a mechanical load is applied, breakage of filaments and the like are not easily generated, and fluff and weaving defects are not easily generated.

(Composition of glass yarn component)

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

The Si content of the glass yarn is preferably 40 to 60 mass%, more preferably 45 to 55 mass%, further preferably 47 to 53 mass%, further preferably 48 to 52 mass%, based on SiO ₂ conversion.

Si is a component forming the skeleton structure of the glass yarn, and the strength of the glass yarn is more easily improved by making the Si content 40 mass% or more. Accordingly, breakage of the glass cloth tends to be further suppressed in the subsequent steps such as the glass cloth manufacturing step and the prepreg manufacturing step using the glass cloth. Further, when the Si content is 40 mass% or more, the dielectric constant of the glass cloth tends to be further lowered. 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 process of producing filaments, and thus glass fibers having a more uniform glass composition tend to be obtained. Therefore, the obtained filaments are less likely to generate a part that is locally likely to be devitrified or a part that is locally difficult to remove bubbles, and therefore, the filaments are less likely to generate a part that is locally low in strength, and as a result, the glass cloth made of the glass yarn obtained by using the filaments is less likely to break. The Si content can be adjusted according to the amount of raw materials used to make the filaments.

The B content of the glass yarn is preferably 15 to 40 mass%, more preferably 17 to 30 mass% or 20 to 40 mass%, further preferably 18 to 28 mass%, further preferably 19 to 26 mass%, still further preferably 20 to 25 mass%, and most preferably 20.5 to 24 mass%, based on the B ₂O₃ conversion.

When the B content is 15 mass% or more, the dielectric constant tends to be further lowered. Further, when the B content is 15 mass% or more, the brittleness resistance of the glass cloth is improved and moderate flexibility and ductility are provided, so that fluff tends not to be generated when the glass yarn contacts loom members such as yarn guides and reed. On the other hand, the B content is preferably 40 mass% or less in order to maintain the strength of the glass yarn. Further, the moisture absorption resistance is improved by setting the B content to 40 mass% or less. The B content can be adjusted according to the amount of raw materials used to make the filaments. In the production of the filament, under the condition that conditions, amounts or contents may vary, the filament may be estimated in advance, and the amount of the raw material to be fed may be adjusted.

The Al content of the glass yarn is preferably 11 to 18 mass%, more preferably 11 to 16 mass%, and still more preferably 12 to 16 mass% in terms of alumina (Al ₂O₃) conversion. When the Al content is in the above range, the electrical characteristics and strength tend to be further improved. The Al content can be adjusted according to the amount of raw materials used to make the filaments.

The Ca content of the glass yarn is preferably 5 to 10 mass%, more preferably 5 to 9 mass%, and still more preferably 5 to 8.5 mass% in terms of calcium oxide (CaO) conversion. When the Ca content is 5 mass% or more, the viscosity at the time of melting tends to be further lowered during the production of the filaments, and glass fibers having a more uniform glass composition tend to be obtained. Further, the Ca content is set to 10 mass% or less, so that the dielectric constant tends to be further improved. The Ca content can be adjusted according to the amount of raw materials used to make the filaments.

The glass yarn may have various excellent characteristics by containing predetermined amounts of Mg, P, na, K, ti, zn, fe and F. These levels can be adjusted depending on the amount of raw materials used to make the filaments.

The above-mentioned contents can be measured by ICP emission spectrometry. Specifically, the Si content and the B content can be obtained by melting a weighed glass cloth sample with sodium carbonate, then dissolving the glass cloth sample with dilute nitric acid, and measuring the resultant sample by ICP emission spectrometry. The Fe content can be obtained by dissolving a weighed glass cloth sample by an alkali dissolution method, fixing the volume, and measuring the obtained sample by an ICP emission spectrometry method. Further, the Al content, ca content and Mg content can be obtained by subjecting a weighed glass cloth sample to thermal decomposition with sulfuric acid, nitric acid and hydrogen fluoride, then dissolving with dilute nitric acid, and then fixing the volume, and measuring the obtained sample by ICP emission spectrometry. As the ICP emission spectroscopic analyzer, PS3520VDD II manufactured by hitachi high tech company can be used.

(Dielectric constant of glass yarn)

The glass yarn preferably has a dielectric constant of 5.0 or less, more preferably 4.9 or less, still more preferably 4.8 or less, and particularly preferably 4.6 or less at a frequency of 10 GHz. The dielectric constant of the glass yarn can be measured by, for example, a cavity resonance method. In the present specification, the dielectric constant of the glass yarn means the dielectric constant at a frequency of 10GHz unless otherwise specified.

(Index of difference between the twist interval length and the twist interval length of glass yarn)

The glass yarn is preferably 1.8 to 10.0cm, more preferably 1.9 to 9.9cm, still more preferably 1.95 to 4.0cm, and most preferably 2.0 to 3.5cm in twist interval length. The minimum value of the twist lay length is preferably 1.8cm, more preferably 1.9cm, further preferably 1.95cm, and most preferably 2.0cm. The maximum value of the twist interval length is preferably 10.0cm, more preferably 9.9cm, further preferably 4.0cm, and most preferably 3.5cm.

The difference between the maximum value and the minimum value of the twist interval length of the glass yarn and the average value of the twist interval length (twist interval length difference index) is preferably 0.7 or less, more preferably 0.6 or less, still more preferably 0.5 or less, most preferably 0.4 or less, and may exceed 0. If the glass yarn has a twist interval length and/or a twist interval length difference index within the above numerical ranges, the number of the slip filaments evaluated at the outer layer portion of the bobbin tends to be3 or less and/or the number of slip filaments over the entire length of the bobbin tends to be small when the glass yarn is wound around the bobbin. Although not wishing to be bound by theory, three reasons for the reduced number of slipping filaments may be considered:

(i) If the twisting gap length is greater than the lower limit value, the torsional shear stress is suppressed to be small, and thus slipping of the filaments is less likely to occur;

(ii) If the twisting space length is smaller than the upper limit value, the binding force between filaments constituting the glass yarn is increased, so that slipping of the filaments is less likely to occur;

(iii) If the twist interval length difference index is smaller than the upper limit value, the fluctuation of the twist angle in the longitudinal direction of the glass yarn is suppressed to be small, and thus the slipping of the filaments is less likely to occur.

The standard deviation of the number of glass yarns is preferably 0.05 to 0.20, more preferably 0.09 to 0.18.

[ Method for producing glass cloth ]

A third embodiment of the present invention is a method for manufacturing a glass cloth.

The present embodiment is a method for producing a glass cloth, which includes a step of weaving a glass yarn including a plurality of filaments by using the warp yarn and the weft yarn.

The glass yarn used was as described above.

(I) TEX is 1-13;

(ii) The breaking strength is 0.50-0.80N/tex, and

(Iii) The number of slipped filaments (the number of filaments from slipping to the average value of yarn width at 180m was 2 times or more, which was 3 or less.

Specifically, the production method includes a glass yarn adjustment step of adjusting glass yarns so that the number of slipped filaments is equal to or less than a specific number, a weaving step of weaving the adjusted glass yarns to obtain a glass cloth, and a fiber opening step of opening the glass yarns of the glass cloth. The method for producing a glass cloth may include a degluing step of removing a sizing agent attached to glass yarns of the glass cloth, and a surface treatment step using a silane coupling agent, if necessary.

Hereinafter, each step in the method for producing a glass cloth will be described in more detail.

(Glass yarn adjustment step)

The glass yarn adjustment step is a step of adjusting the glass yarn so that the number of slipped filaments becomes 3 or less. More specifically, in the glass yarn adjustment step, if the number of slipped filaments is within the above range, the glass yarn is then used in the weaving step, and if it is out of the range, the use of the glass yarn in the glass yarn is inhibited.

Examples of the method for measuring the number of slipped filaments include a method for observing the yarn width and slipped filaments by a displacement meter using an optical projection system such as laser and LED light while carrying the glass yarn, and a method for observing the yarn width and slipped filaments while carrying the glass yarn and observing the shape of the glass yarn in an image.

(Weaving Process)

The weaving step is a step of weaving glass yarns to obtain glass cloth. Examples of the woven structure of the glass cloth include a woven structure such as a plain weave, a basket weave, a satin weave, and a twill weave. Of these, a plain weave structure is more preferable.

In an example of the weaving process in the manufacturing method of the present embodiment, the warp yarn drawn in parallel is opened up and down by an air jet loom, and the yarn discharged from the weft yarn storage device is fed out as weft yarn by jet flow of a nozzle and passed through the opening, whereby weaving can be performed.

In the weaving process, the glass yarn serving as the weft yarn is reeled out from the spool, and in the glass yarn spraying process of spraying the weft yarn by the storage device,

The glass yarn is carried with the movement of the balloon movement and the like in a direction different from the advancing direction and with the interference with the loom members such as the yarn guides, or

Since the ejection and stopping of the weft yarn are repeated for 1 length of the weft yarn, the weft yarn is carried along with the fluctuation of the tension and the interference with the loom members such as the yarn guides;

therefore, it is difficult to suppress the damage caused by the interference to a small extent by the weft yarn having a large number of slipped filaments, and the resultant glass cloth may have fluff or weaving defects.

In contrast, in the present embodiment, the use of glass yarns having the number of slip filaments within a specific range suppresses the generation of fluff or weaving defects during weft knitting, and can thereby improve the in-plane uniformity and the batch-to-batch uniformity of the quality of the glass cloth. 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 weft count of warp yarns and weft yarns constituting the glass cloth is preferably 30 to 120 yarns/25 mm, more preferably 40 to 110 yarns/25 mm, and even more preferably 45 to 105 yarns/25 mm. The beat-up density of the warp yarns can be controlled by adjusting the interval of the warp yarns drawn side by side and the beat-up density of the weft yarns can be controlled by the number of jets per unit time of the weft yarns from the nozzles and the flow rate of the warp yarns.

(Open fiber procedure)

The opening step is a step of opening glass yarns of the glass cloth. As the fiber opening method, for example, a method of opening fiber by using spray water (high-pressure water opening), a vibration washer, ultrasonic water, a calender, or the like is mentioned.

The thickness of the glass cloth finally obtained by the fiber opening step is preferably 5 to 60. Mu.m, more preferably 7 to 55. Mu.m, still more preferably 9 to 50. Mu.m, or 10 to 50. Mu.m. By setting the thickness of the glass cloth within the above range, a glass cloth having a thin and high strength tends to be obtained. The cloth weight (weight per unit area) of the glass cloth finally obtained through the opening step or the like is preferably 5 to 55g/m ², more preferably 6 to 50g/m ², still more preferably 7 to 48g/m ².

(Degumming Process)

The degumming step is a step of removing a sizing agent attached to glass yarns of the glass cloth. As the degumming method, for example, a method of removing the sizing agent by heating is mentioned.

(Surface treatment step)

The surface treatment step is a step of treating the surface of the glass cloth with a silane coupling agent. The surface treatment method includes a method of bringing a surface treatment agent containing a silane coupling agent into contact with a glass cloth and drying the same. The contact between the surface treatment agent and the glass cloth includes a method of impregnating the glass cloth with the surface treatment agent, a method of applying the surface treatment agent to the glass cloth by using a roll coater, a die coater, a gravure coater, or the like, and the like. The method of drying the surface treatment agent is not particularly limited, and examples thereof include a hot air drying method and a drying method using electromagnetic waves.

[ Prepreg ]

The prepreg includes the glass cloth obtained by the above-described operation and the base resin composition impregnated into the glass cloth. The prepreg having the glass cloth has little quality deviation, and the yield of the final product is high.

The prepreg may be manufactured according to a conventional method. For example, the glass cloth is impregnated with a varnish obtained by diluting a base resin such as an epoxy resin with an organic solvent, and then the organic solvent is volatilized in a drying oven, whereby the thermosetting resin is cured to a B-stage state (semi-cured state).

Examples of the base resin composition include thermosetting resins such as bismaleimide resin, cyanate ester resin, unsaturated polyester resin, polyimide resin, BT resin, and functionalized polyphenylene ether resin, thermoplastic resins such as polyphenylene ether resin, polyetherimide resin, liquid Crystal Polymer (LCP) of wholly aromatic polyester, polybutadiene, and fluororesin, and mixed resins thereof, in addition to the epoxy resin. From the viewpoint of improving dielectric characteristics, heat resistance, solvent resistance and press formability, a resin obtained by modifying a thermoplastic resin with a thermosetting resin can be used as the base resin composition.

The base resin composition may contain inorganic fillers such as silica and aluminum hydroxide, flame retardants such as bromine-based, phosphorus-based and metal hydroxides, silane coupling agents, heat stabilizers, antistatic agents, ultraviolet absorbers, pigments, colorants, lubricants, and the like.

[ Printed Circuit Board ]

The printed circuit board preferably includes the prepreg. The printed wiring board provided with the prepreg has little quality deviation, and the yield of the final product is high. The printed wiring board provided with the prepreg has the advantage that the influence of the use environment, particularly the fluctuation of the dielectric constant in a high humidity environment, is small because the prepreg is excellent in dielectric characteristics and moisture absorption resistance.

Examples

Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples.

[ Properties of glass yarn and glass cloth ]

Physical properties of the glass yarn and the glass cloth, specifically, thickness of the glass cloth, average diameter of filaments constituting the glass yarn, TEX of the glass yarn, breaking strength (tensile strength) of the glass yarn, and beat-up density (weaving density) of warp and weft were measured in accordance with JIS R3420.

[ Twist interval Length, twist interval Length Difference index ]

The number of turns of the glass yarn of 50cm was measured using a twist tester (TEKNOS Co.) and the length of each 1 interval of the turns was calculated by dividing the measured length of 50cm by the number of turns obtained. With this method, 30 points are repeatedly measured for each 50cm number of twists, the length of each 1 interval of the twists is calculated, and the length data of each 1 interval of the twists is calculated at 30 points. The length data of each 1 interval of the 30 twists obtained were averaged to obtain a twist interval length.

Further, using the average value, the maximum value, and the minimum value of the obtained 30-point twist interval length data, the twist interval length difference index is obtained by the following formula (1) as the ratio of the difference between the maximum value and the minimum value of the twist interval length to the average value of the twist interval length.

Twist interval length difference exponent = { (maximum value of twist interval length-twist interval) minimum length)/twist interval length mean }. Times.100. 16 (1)

[ Standard deviation of twist number ]

The number of turns of the glass yarn of 50cm was measured using a twist tester (TEKNOS Co., ltd.) and converted into the number of turns per 25 mm. By this method, the number of turns per 25mm at 30 was repeatedly measured, and the standard deviation of the number of turns data at 30 was obtained.

[ Coefficient of elasticity ]

The elastic modulus of the glass yarn was measured by a pulse-echo-overlap method (pulse-echo-overlap method) using a glass block obtained by melting and cooling the glass yarn as a test piece.

[ Number of slipped filaments ]

The yarn width was measured continuously by observing the projected shape of the glass yarn with a monitor while the glass yarn was conveyed at a speed of 1 m/min by using an LED camera type size measuring instrument (HIGH ACCURACY CMOS MICROMETER LS-9006 MR/kenshi). The yarn width of the glass yarn was measured by 180m, and the average value of the yarn width of the glass yarn was calculated from the obtained yarn width data. The filament slippage was counted up at a position 2 times or more the yarn width from the center of the yarn width, and the total was taken as the "slippage filament number", that is, the "number of filaments slipping to 2 times or more the average value of the yarn width at 180m measurement".

Here, the yarn width measurement by the LED camera type size measuring instrument was performed under the condition that 1934 measured values were obtained every 1m, and when errors occurred due to focusing failure of the LED or the like (a value of-9999 was displayed), the measured values were deleted, and the average yarn width and/or the number of slipped filaments were calculated.

The tension applied to the glass yarn during conveyance of the glass yarn is a tension measured by a tensiometer (Conrol instruments ETPB-100-C0585, manufactured by SCHMIT Co.) and is 0.12 to 0.18N.

[ Inspection of spool appearance (fluff inspection) ]

The appearance of the spool wound with the glass yarn was visually inspected, and the number of fluffs (fluff number) detected was counted. This test was performed 50 times, and the average value of the number of fluff strips was calculated.

[ Fluff examination of glass yarn for evaluation by applying a load to the glass yarn ]

The yarn was passed through a model reed having a reed blade spacing distance of 0.35mm for 1 minute round-trip 450 times while being conveyed at a speed of 1 m/min by using a fluff inspection device manufactured by NIHON KAGAKU ENG, and after hairiness was given, the number of fluff generation per 180m was counted by a sensor. The round-trip speed of the model reed was set to 100 rounds/min, and the number of fluff produced per 180m was counted by the same sensor.

[ Evaluation of fluff quality of glass cloth ]

The effect of glass yarn quality (e.g., the number of slipped filaments) on the fluff quality of the glass cloth was examined. As standard conditions for glass cloth production, the loom rotation speed was set to 450rpm, and the fiber-opening treatment was performed by high-pressure water spraying. Further, the rotational speed of the loom (550, 600 rpm) was increased in order to improve productivity, and the high-pressure water spray strength was increased in order to improve characteristics.

The fluff quality of the glass cloths obtained in examples, comparative examples and reference examples was evaluated by visual inspection of the cloths. The quality of the nap of the glass cloth was evaluated visually while conveying the glass cloth at a speed of 10 m/min using a cloth inspecting machine for glass cloth. In the conventional visual inspection, the fluff and the weaving defect were observed at a portion where the glass cloth was irradiated with halogen lamp light in a right angle direction and reflected. However, in order to observe the filament broken nap with a length of less than 1mm with good sensitivity, white LED light was irradiated from the end side of the glass cloth in a direction parallel to the glass cloth face, and visual inspection was performed. Since the entire surface of the glass cloth on the cloth inspecting plate is scattered with the naps, the nap generation state observed by the light emission on the entire surface of the glass cloth is regarded as the entire surface nap defect. The entire fluff generation site was observed by an optical microscope, and as a result, a large amount of fluff due to filament breakage of about 200 μm to 1000 μm was generated.

Regarding the measurement length of 500m, when the entire fluff is present within 1m in the longitudinal direction of the glass cloth, the number of defects is counted as 1, and the score is calculated according to the following formula:

The deduction rate (%) = (total of statistics of drawbacks/500) ×100.

[ Evaluation of impregnation Property of glass cloth ]

A bisphenol A type epoxy resin was dissolved in benzyl alcohol at 23.+ -. 2 ℃ to prepare a varnish for evaluating impregnation property having a viscosity of 230.+ -.5 mPas. Next, the glass cloth test piece was immersed in the impregnating varnish, and the state in which the glass cloth was impregnated with the impregnating varnish was observed by an optical microscope while light was irradiated from the lateral direction. The number of voids (portions not impregnated with the varnish for evaluating the impregnation property) after 5 minutes from the impregnation of the glass cloth test piece with the varnish for evaluating the impregnation property was counted. In this case, the visual field of the glass cloth observed by an optical microscope was set to be about 6.5mm in the warp direction and about 9mm in the weft direction.

[ Examples and comparative examples; glass yarn ]

[ Test example 1]

Glass yarns A to N (low dielectric glass yarn, density of 2.3g/cm ³, elastic coefficient of 61 GPa), O to Q (low dielectric glass yarn, density of 2.3g/cm ³, elastic coefficient of 56 GPa) and R (E glass yarn, density of 2.6g/cm ³, elastic coefficient of 74 GPa) which were in a state of being wound around the spool were pulled out from the outermost layer of the spool, and a portion 5m apart from the end in the longitudinal direction was used as a starting point T ₀, and the number of slipped filaments was measured.

[ Test example 2]

Next, the number of slipped filaments was measured using a position where the 500m glass yarn was pulled out from the spool, that is, a position 500m apart from the starting point T ₀ in the longitudinal direction, as the starting point T ₅₀₀.

[ Test example 3]

According to the above test examples 1 and 2, the glass yarn was pulled further from the spool,

A portion which is 1,000m from the start point T ₀ in the longitudinal direction is set as a start point T _1,000;

A portion which is 2,000m from the start point T ₀ in the longitudinal direction is set as a start point T _2,000;

a portion which is 5,000m from the start point T ₀ in the longitudinal direction is set as a start point T _5,000;

A portion which is 7,000m from the start point T ₀ in the longitudinal direction is set as a start point T _7,000;

A portion which is 9,000m from the start point T ₀ in the longitudinal direction is set as a start point T _9,000;

a portion which is 10,000m from the start point T ₀ in the longitudinal direction is set as a start point T _10,000;

a portion which is 20,000m from the start point T ₀ in the longitudinal direction is set as a start point T _20,000;

A portion which is 30,000m from the start point T ₀ in the longitudinal direction is set as a start point T _30,000;

A portion which is 40,000m from the start point T ₀ in the longitudinal direction is set as a start point T _40,000;

a portion which is 50,000m from the start point T ₀ in the longitudinal direction is set as a start point T _50,000;

a portion which is 60,000m from the start point T ₀ in the longitudinal direction is set as a start point T _60,000;

a portion which is 70,000m from the start point T ₀ in the longitudinal direction is set as a start point T _70,000;

A portion distant from the start point T ₀ by 80,000m in the longitudinal direction is set as a start point T _80,000;

A portion which is 100,000m from the start point T ₀ in the longitudinal direction is set as a start point T _100,000;

A portion distant from the start point T ₀ by 120,000m in the longitudinal direction is set as a start point T _120,000;

the number of slipped filaments was measured. The results obtained are shown in Table 1.

[ Table 1-1]

[ Tables 1-2]

The glass yarns A-C, G, H, J, K, O, P of the examples having small twist interval length difference index and being twisted uniformly and gently have the number of slip filaments evaluated at the outer layer of the spool of 3 or less.

When any of the starting points T ₀, T ₅₀₀, T _1,000, T _2,000, T _5,000, T _7,000, and T _9,000 is measured, the number of slipped filaments is 3 or less. It was confirmed that, when the measurement ranges of 180m in the longitudinal direction were selected at 5 different points with respect to glass yarns having a length of 10,000m or more, the number of slipped filaments was 3 or less within the measurement ranges at 5 points.

Even if glass yarns having a length of 50,000m or more are used, if the measurement ranges of 180m in the longitudinal direction are selected at 7 different points from each other, the number of slipped filaments is 3 or less within the measurement ranges at 7 points.

It was confirmed that even when a glass yarn having a length of 100,000m or more was used, the number of slipped filaments was 3 or less in the measurement range at 10 points, when the measurement range of 180m in the longitudinal direction was selected at 10 points different from each other, based on the same principle as described above.

On the other hand, the number of slip filaments in the predetermined measurement range of the glass yarns D to F, I, L to N, Q, R of the comparative examples having a large difference in the twist interval length index was 4 or more.

[ Example 1]

A glass cloth fabric having a warp yarn weaving density of 65 pieces/25 mm and a weft yarn weaving density of 67 pieces/25 mm was obtained by using low dielectric glass yarns (TEX: 4.9, number of filaments: 100, elastic modulus: 61GPa, glass composition: 51.2% by mass of SiO ₂, 14.3% by mass of Al ₂O₃, 8.1% by mass of CaO, 0.3% by mass of MgO, 23.3% by mass of B ₂O₃, and 0.1% by mass of P ₂O₃) described in the following table for warp yarns and weft yarns, and using an air jet loom at a loom speed of 450rpm (weft yarn weaving speed: 450 pieces/min).

In the table, as shown in the item "number of slipped filaments measured at the starting point T ₀", in example 1, glass yarn having 0 number of filaments slipped to 2 times or more of the average yarn width value when measured 180m from the starting point T ₀ was used.

Then, the glass cloth was degummed by heating the glass cloth, and high-pressure water-jet-break was performed by spraying water pressure was adjusted to 5.0.+ -. 0.1kg/cm ², followed by surface treatment with a silane coupling agent to produce a glass cloth having a thickness of 29. Mu.m.

[ Example 2]

A glass cloth having a thickness of 29 μm was produced in the same manner as in example 1, except that the low dielectric glass yarns (TEX: 4.9, the number of filaments: 100, the elastic modulus: 61GPa, the glass composition: siO ₂: 51.2% by mass, al ₂O₃: 14.3% by mass, caO: 8.1% by mass, mgO: 0.3% by mass, B ₂O₃: 23.3% by mass, and P ₂O₃: 0.1% by mass) described in the following table were used.

[ Example 3]

A glass cloth having a thickness of 29 μm was produced in the same manner as in example 1, except that the low dielectric glass yarns (TEX: 4.9, the number of filaments: 100, the elastic modulus: 61GPa, the glass composition: siO ₂: 51.2% by mass, al ₂O₃: 14.3% by mass, caO: 8.1% by mass, mgO: 0.3% by mass, B ₂O₃: 23.3% by mass, and P ₂O₃: 0.1% by mass) described in the following table were used.

[ Example 4]

A glass cloth having a thickness of 29 μm was produced in the same manner as in example 1, except that the low dielectric glass yarns (TEX: 4.9, the number of filaments: 100, the elastic modulus: 61GPa, the glass composition: siO ₂: 51.2% by mass, al ₂O₃: 14.3% by mass, caO: 8.1% by mass, mgO: 0.3% by mass, B ₂O₃: 23.3% by mass, and P ₂O₃: 0.1% by mass) described in the following table were used.

Comparative example 1

A glass cloth having a thickness of 29 μm was produced in the same manner as in example 1, except that the low dielectric glass yarns (TEX: 4.9, the number of filaments: 100, the elastic modulus: 61GPa, the glass composition: siO ₂: 51.2% by mass, al ₂O₃: 14.3% by mass, caO: 8.1% by mass, mgO: 0.3% by mass, B ₂O₃: 23.3% by mass, and P ₂O₃: 0.1% by mass) described in the following table were used.

Comparative example 2

A glass cloth having a thickness of 29 μm was produced in the same manner as in example 1, except that the low dielectric glass yarns (TEX: 4.9, the number of filaments: 100, the elastic modulus: 61GPa, the glass composition: siO ₂: 51.2% by mass, al ₂O₃: 14.3% by mass, caO: 8.1% by mass, mgO: 0.3% by mass, B ₂O₃: 23.3% by mass, and P ₂O₃: 0.1% by mass) described in the following table were used.

[ Comparative example 3]

A glass cloth having a thickness of 29 μm was produced in the same manner as in example 1, except that the low dielectric glass yarns (TEX: 4.9, the number of filaments: 100, the elastic modulus: 61GPa, the glass composition: siO ₂: 51.2% by mass, al ₂O₃: 14.3% by mass, caO: 8.1% by mass, mgO: 0.3% by mass, B ₂O₃: 23.3% by mass, and P ₂O₃: 0.1% by mass) described in the following table were used.

[ Example 5]

A glass cloth having a thickness of 29 μm was produced in the same manner as in example 1, except that the rotational speed of the air jet loom was set to 550 rpm.

[ Example 6]

A glass cloth having a thickness of 29 μm was produced in the same manner as in example 3, except that the rotational speed of the air jet loom was set to 550 rpm.

[ Comparative example 4]

Glass cloth having a thickness of 29 μm was produced in the same manner as in comparative example 1 except that the rotational speed of the air jet loom was set to 550 rpm.

Example 7

A glass cloth having a thickness of 29 μm was produced in the same manner as in example 1, except that the rotational speed of the air jet loom was changed to 600 rpm.

Example 8

A glass cloth having a thickness of 29 μm was produced in the same manner as in example 3, except that the rotational speed of the air jet loom was changed to 600 rpm.

[ Comparative example 5]

Glass cloth having a thickness of 29 μm was produced in the same manner as in comparative example 1 except that the rotational speed of the air jet loom was changed to 600 rpm.

[ Example 9]

A glass cloth having a thickness of 29 μm was produced in the same manner as in example 1, except that the water pressure of the high-pressure water spray during the fiber opening treatment was increased to 12.0±0.1kg/cm ² to increase the fiber opening strength.

[ Example 10 ]

A glass cloth having a thickness of 29 μm was produced in the same manner as in example 3, except that the water pressure of the high-pressure water spray during the fiber opening treatment was increased to 12.0±0.1kg/cm ² to increase the fiber opening strength.

[ Comparative example 6]

A glass cloth having a thickness of 29 μm was produced in the same manner as in comparative example 1, except that the water pressure of the high-pressure water spray during the fiber opening treatment was increased to 12.0±0.1kg/cm ² to increase the fiber opening strength.

Comparative example 7

A glass cloth having a thickness of 29 μm was produced in the same manner as in comparative example 2, except that the water pressure of the high-pressure water spray during the fiber opening treatment was increased to 12.0±0.1kg/cm ² to increase the fiber opening strength.

Comparative example 8

A glass cloth having a thickness of 29 μm was produced in the same manner as in comparative example 3, except that the water pressure of the high-pressure water spray during the fiber opening treatment was increased to 12.0±0.1kg/cm ² to increase the fiber opening strength.

[ Example 11]

The low dielectric glass yarn (TEX: 2.9, filament count: 100, elastic modulus: 61GPa, glass composition: siO ₂: 51.2 mass%, al ₂O₃: 14.3 mass%, caO: 8.1 mass%, mgO: 0.3 mass%, B ₂O₃: 23.3 mass%, P ₂O₃: 0.1 mass%) described in the following table was used for warp and weft, and a glass cloth fabric having a warp weaving density of 74 pieces/25 mm and a weft weaving density of 74 pieces/25 mm was obtained under the condition that the loom rotational speed of an air jet loom was 450rpm (weft weaving-in speed: 450 pieces/min).

Then, the glass cloth was degummed by heating the glass cloth, high-pressure water-splitting was performed by spraying water pressure was adjusted to 4.0.+ -. 0.1kg/cm ², and then surface treatment was performed using a silane coupling agent to prepare a glass cloth having a thickness of 21. Mu.m.

[ Example 12]

A glass cloth having a thickness of 21 μm was produced in the same manner as in example 11, except that the low dielectric glass yarns (TEX: 2.9, the number of filaments: 100, the elastic modulus: 61GPa, the glass composition: siO ₂: 51.2% by mass, al ₂O₃: 14.3% by mass, caO: 8.1% by mass, mgO: 0.3% by mass, B ₂O₃: 23.3% by mass, and P ₂O₃: 0.1% by mass) described in the following table were used.

Comparative example 9

A glass cloth having a thickness of 21 μm was produced in the same manner as in example 11, except that the low dielectric glass yarns (TEX: 2.9, the number of filaments: 100, the elastic modulus: 61GPa, the glass composition: siO ₂: 51.2% by mass, al ₂O₃: 14.3% by mass, caO: 8.1% by mass, mgO: 0.3% by mass, B ₂O₃: 23.3% by mass, and P ₂O₃: 0.1% by mass) described in the following table were used.

[ Example 13]

A glass cloth having a thickness of 21 μm was produced in the same manner as in example 11, except that the water pressure of the high-pressure water spray during the fiber opening treatment was increased to 10.0±0.1kg/cm ² to increase the fiber opening strength.

[ Comparative example 10 ]

A glass cloth having a thickness of 21 μm was produced in the same manner as in comparative example 9, except that the water pressure of the high-pressure water spray during the fiber opening treatment was increased to 10.0±0.1kg/cm ² to increase the fiber opening strength.

[ Example 14]

A low dielectric glass yarn (TEX 9.8, filament count 200, elastic modulus 61GPa, glass composition: siO ₂ was converted to 51.2 mass%, al ₂O₃ was converted to 14.3 mass%, caO was converted to 8.1 mass%, mgO was converted to 0.3 mass%, B ₂O₃ was converted to 23.3 mass%, and P ₂O₃ was converted to 0.1 mass%) described in the following table was used for warp and weft, and a glass cloth fabric having a warp weaving density of 52.5 pieces/25 mm and a weft weaving density of 52.5 pieces/25 mm was obtained under the condition that the loom rotational speed of an air jet loom was 450rpm (weft weaving speed was 450 pieces/min).

Then, the glass cloth was degummed by heating the glass cloth, high-pressure water-splitting was performed by spraying water pressure was adjusted to 6.0.+ -. 0.1kg/cm ², and then surface treatment was performed using a silane coupling agent to prepare a glass cloth having a thickness of 46. Mu.m.

[ Example 15]

A glass cloth having a thickness of 46 μm was produced in the same manner as in example 14, except that the low dielectric glass yarns (TEX 9.8, filament count 200, elastic modulus 61GPa, glass composition: siO ₂ was 51.2% by mass, al ₂O₃ was 14.3% by mass, caO was 8.1% by mass, mgO was 0.3% by mass, B ₂O₃ was 23.3% by mass, and P ₂O₃ was 0.1% by mass) described in the following table were used.

Comparative example 11

A glass cloth having a thickness of 46 μm was produced in the same manner as in example 14, except that the low dielectric glass yarns (TEX 9.8, filament count 200, elastic modulus 61GPa, glass composition: siO ₂ was 51.2% by mass, al ₂O₃ was 14.3% by mass, caO was 8.1% by mass, mgO was 0.3% by mass, B ₂O₃ was 23.3% by mass, and P ₂O₃ was 0.1% by mass) described in the following table were used.

[ Example 16]

A glass cloth having a thickness of 46 μm was produced in the same manner as in example 14, except that the water pressure of the high-pressure water spray during the fiber opening treatment was increased to 12.0±0.1kg/cm ² to increase the fiber opening strength.

[ Comparative example 12]

A glass cloth having a thickness of 46 μm was produced in the same manner as in comparative example 11, except that the water pressure of the high-pressure water spray during the fiber opening treatment was increased to 12.0±0.1kg/cm ² to increase the fiber opening strength.

[ Example 17]

A low dielectric glass yarn (TEX: 4.8, number of filaments: 100, elastic modulus: 56GPa, glass composition: 49.8% by mass of SiO ₂, 16.8% by mass of Al ₂O₃, 3.1% by mass of CaO, 0.1% by mass of MgO, 23.9% by mass of B ₂O₃, and 4.0% by mass of P ₂O₃) described in the following table was used for warp and weft, and a glass cloth fabric having a warp weaving density of 65/25mm and a weft weaving density of 67/25 mm was obtained under the condition that the rotational speed of a jet loom was 450rpm (weft weaving speed was 450 pieces/min).

Then, the glass cloth was degummed by heating the glass cloth, high-pressure water-splitting was performed by spraying water pressure was adjusted to 5.0.+ -. 0.1kg/cm ², and then surface treatment was performed using a silane coupling agent to prepare a glass cloth having a thickness of 31. Mu.m.

[ Example 18]

A glass cloth having a thickness of 31 μm was produced in the same manner as in example 17, except that the low dielectric glass yarns (TEX: 4.8, the number of filaments: 100, the elastic modulus: 56GPa, the glass composition: 49.8% by mass of SiO ₂, 16.8% by mass of Al ₂O₃, 3.1% by mass of CaO, 0.1% by mass of MgO, 23.9% by mass of B ₂O₃, and 4.0% by mass of P ₂O₃) described in the following table were used.

[ Comparative example 13]

A glass cloth having a thickness of 31 μm was produced in the same manner as in example 15, except that the low dielectric glass yarns (TEX: 4.8, the number of filaments: 100, the elastic modulus: 56GPa, the glass composition: 49.8% by mass of SiO ₂, 16.8% by mass of Al ₂O₃, 3.1% by mass of CaO, 0.1% by mass of MgO, 23.9% by mass of B ₂O₃, and 4.0% by mass of P ₂O₃) described in the following table were used.

[ Example 19 ]

A glass cloth having a thickness of 31 μm was produced in the same manner as in example 17, except that the water pressure of the high-pressure water spray during the fiber opening treatment was increased to 12.0±0.1kg/cm ² to increase the fiber opening strength.

[ Comparative example 14]

A glass cloth having a thickness of 31 μm was produced in the same manner as in comparative example 13, except that the water pressure of the high-pressure water spray during the fiber opening treatment was increased to 12.0±0.1kg/cm ² to increase the fiber opening strength.

[ Reference example 1a ]

A low dielectric glass yarn (TEX: 14.6, filament count: 200, elastic modulus: 61GPa, glass composition: siO ₂: 51.2 mass%, al ₂O₃: 14.3 mass%, caO: 8.1 mass%, mgO: 0.3 mass%, B ₂O₃: 23.3 mass%, P ₂O₃: 0.1 mass%) having a number of slip filaments was used for warp and weft yarns, and a glass cloth fabric having a warp weaving density of 59 pieces/25 mm and a weft weaving density of 61 pieces/25 mm was obtained under the condition that the loom rotational speed of an air jet loom was 450rpm (weft weaving speed was 450 pieces/min).

Then, the glass cloth was degummed by heating the glass cloth, high-pressure water-splitting was performed by spraying water pressure was adjusted to 7.0.+ -. 0.1kg/cm ², and then surface treatment was performed using a silane coupling agent to prepare a glass cloth having a thickness of 73. Mu.m.

[ Reference example 1b ]

A glass cloth having a thickness of 73 μm was produced in the same manner as in reference example 1a, except that the water pressure of the high-pressure water spray during the fiber opening treatment was increased to 12.0±0.1kg/cm ² to increase the fiber opening strength.

[ Reference example 2a ]

A low dielectric glass yarn (TEX: 19.4, filament count: 200, elastic modulus: 61GPa, glass composition: siO ₂: 51.2 mass%, al ₂O₃: 14.3 mass%, caO: 8.1 mass%, mgO: 0.3 mass%, B ₂O₃: 23.3 mass%, P ₂O₃: 0.1 mass%) having a number of slip filaments was used for warp and weft yarns, and a glass cloth fabric having a warp weaving density of 60 pieces/25 mm and a weft weaving density of 57 pieces/25 mm was obtained under the condition that the loom rotational speed of an air jet loom was 450rpm (weft weaving speed was 450 pieces/min).

Then, the glass cloth was degummed by heating the glass cloth, high-pressure water-splitting was performed by spraying water pressure was adjusted to 7.0.+ -. 0.1kg/cm ², and then surface treatment was performed using a silane coupling agent to prepare a glass cloth having a thickness of 89. Mu.m.

[ Reference example 2b ]

A glass cloth having a thickness of 89 μm was produced in the same manner as in reference example 2a, except that the water pressure of the high-pressure water spray during the fiber-opening treatment was increased to 12.0±0.1kg/cm ² to increase the fiber-opening strength.

[ Reference example 3a ]

An E glass yarn (TEX: 5.5, filament count: 100, elastic modulus: 74GPa, glass composition: 53.1 mass% SiO ₂, 15.3 mass% Al ₂O₃, 21.0 mass% CaO, 1.9 mass% MgO, 8.0 mass% B ₂O₃, and <0.1 mass%) having a number of slipping filaments was used for warp and weft yarns, and a glass cloth fabric having a warp weaving density of 65 yarns/25 mm and a weft weaving density of 67 yarns/25 mm was obtained under the condition that the loom speed of an air jet loom was 450rpm (weft weaving speed was 450 yarns/min).

Then, the glass cloth was degummed by heating the glass cloth, high-pressure water-splitting was performed by spraying water pressure was adjusted to 5.0.+ -. 0.1kg/cm ², and then surface treatment was performed using a silane coupling agent to prepare a glass cloth having a thickness of 29. Mu.m.

[ Reference example 3b ]

A glass cloth having a thickness of 89 μm was produced in the same manner as in reference example 3a, except that the water pressure of the high-pressure water spray during the fiber-opening treatment was increased to 12.0±0.1kg/cm ² to increase the fiber-opening strength.

The results of the evaluation of the glass yarns and glass cloths in the above examples, comparative examples and reference examples are shown in the following table. In the table, the expression "±0.1 (kg/cm ²)" is omitted from the item of "water pressure at the time of opening fiber with high-pressure water (kg/cm ²)".

[ Table 2-1]

TABLE 2-1

[ Table 2-2]

TABLE 2-2

[ Tables 2 to 3]

Tables 2 to 3

[ Tables 2 to 4]

Tables 2 to 4

[ Tables 2 to 5]

Tables 2 to 5

[ Tables 2 to 6]

Tables 2 to 6

[ Tables 2 to 7]

Tables 2 to 7

[ Tables 2 to 8]

Tables 2 to 8

[ Tables 2 to 9]

Tables 2 to 9

Examples 1 to 4, examples 11 to 12, examples 14 to 15, and examples 17 to 18 can give glass cloths excellent in pile quality. Since the glass yarn used in these examples had 3 or less slipped filaments measured from the starting point T ₀, it was estimated that the glass yarn wound around the spool had a small slipped filaments. It was confirmed that using such glass yarn can provide a glass cloth excellent in fluff quality.

In examples 5 to 8, even if the loom rotation speed was increased from 450rpm to 550rpm or 600rpm in order to increase productivity in the weaving process, the nap quality was not significantly deteriorated, and a glass cloth having relatively good nap quality could be obtained.

Examples 9, 10, 13, 16, and 19 obtained low dielectric glass cloths with improved impregnation properties while maintaining relatively good fluff quality by increasing the water pressure of high-pressure water spray.

On the other hand, the glass cloths obtained in comparative examples 1 to 3, comparative example 9, comparative example 11, and comparative example 13 were poor in fluff quality.

Further, in comparative examples 4 to 8, 10, 12 and 14, when the rotational speed of the loom was increased from 450rpm to 550rpm or 600rpm in the weaving step or the water pressure of the high-pressure water spray was increased in the opening step, glass cloths having significantly deteriorated fluff quality were obtained.

In reference examples 1 (a, b) and 2 (a, b), the thicknesses were 73 μm and 89 μm, respectively, and the glass cloths of examples 1 to 16 were not thin.

In reference examples 3 (a and b) using E glass yarns, a glass cloth having relatively good fluff quality was obtained. In the low dielectric glass yarn having the same TEX, if the number of slipped filaments is large, the fluff quality tends to be deteriorated due to the increase of the spray pressure of the high-pressure water spray (comparative examples 1 to 3, 6 to 8), whereas in the case of the result of reference example 3, such a tendency was not confirmed in the E glass yarn.

In examples 1 to 4 and comparative examples 1 to 3, the results of "slipping filament number" reflected the nap quality of the glass cloth more than "spool appearance inspection" and "nap generation number due to the load applied to the glass yarn".

Claims (46)

1. A glass cloth obtained by weaving glass yarns containing a plurality of glass filaments as warp yarns and weft yarns, The glass cloth comprises the glass yarn that meets the following conditions: (i) TEX is 1 to 13; (ii) a breaking strength of 0.50 to 0.80 N/tex; and (iii) the number of filaments slipping to more than twice the average yarn width when measuring 180 m is 3 or less, The dielectric constant of the glass yarn is less than 5.0 at a frequency of 10 GHz, Taking 500 m of the glass cloth in the longitudinal direction as the object, irradiate the white LED light along the cloth surface, observe every 1 m in the longitudinal direction, and when the number of defects is counted as 1 in the case where there is fluff on the entire surface of the cloth surface, the deduction rate expressed by the following formula is 0 to 3.5%, Deduction rate % = (total number of defects/500) × 100%, The whole-surface fluff includes 200-1000 μm of fluff observed on the surface of the fabric using an optical microscope and caused by the breakage of the filaments. 2 . The glass cloth according to claim 1 , wherein the deduction rate is 3.0% or less. The glass cloth according to claim 1 , wherein the deduction rate is 2.9% or less. 4 . The glass cloth according to claim 1 , wherein the glass cloth has a thickness of 10 to 50 μm. 5. The glass cloth according to claim 1, comprising the glass yarn satisfying the following conditions: (i) TEX is 1.5 to 12; (ii) a breaking strength of 0.53 to 0.79 N/tex; and (iii) The number of filaments which slipped to twice or more of the average yarn width when measuring 180 m is 2 or less. 6. The glass cloth according to claim 1, comprising the glass yarn satisfying the following conditions: (i) TEX is 2.0 to 11; (ii) a breaking strength of 0.57 to 0.78 N/tex; and (iii) The number of filaments which slipped to twice or more of the average yarn width when measuring 180 m was 1 or less. 7. The glass cloth according to claim 1, comprising the glass yarn satisfying the following conditions: (i) TEX is 1 to 7; (ii) a breaking strength of 0.60 to 0.77 N/tex; and (iii) The number of filaments which slipped to twice or more of the average yarn width when measuring 180 m was 0. 8 . The glass cloth according to claim 1 , comprising the glass yarn having a twist interval length of 1.8 to 10.0 cm. 9. The glass cloth according to claim 1, comprising the glass yarn having a twist interval length difference index of 0.7 or less, wherein the twist interval length difference index is a value obtained by dividing the difference between the maximum twist interval length and the minimum twist interval length of the glass yarn by the average twist interval length. 10 . The glass cloth according to claim 9 , wherein the twist interval length difference index is 0.6 or less. The glass cloth according to claim 9 , wherein the twist interval length difference index is 0.5 or less. 12 . The glass cloth according to claim 9 , wherein the twist interval length difference index is 0.4 or less. 13. The glass cloth according to any one of claims 1 to 12, wherein the glass yarn has a length of 10,000 m or more. When a measurement range of 180 m in the longitudinal direction is selected at five different locations, the number of filaments that slipped to twice or more of the average yarn width is 3 or less in each of the five measurement ranges. 14. The glass cloth according to any one of claims 1 to 12, wherein the glass yarn has a length of 50,000 m or more. When a measurement range of 180 m in the longitudinal direction is selected at seven different locations, the number of filaments that slipped to twice or more of the average yarn width is three or less in each of the seven measurement ranges. 15. The glass cloth according to any one of claims 1 to 12, wherein the glass yarn has a length of 100,000 m or more. When a measurement range of 180 m in the longitudinal direction is selected at 10 different locations, the number of filaments that slipped to more than twice the average yarn width is 3 or less in each of the 10 measurement ranges. 16. A method for producing glass cloth, comprising the steps of using glass yarns containing a plurality of glass filaments as warp yarns and weft yarns and weaving them, (i) the TEX of the glass yarn is 1 to 13; (ii) the breaking strength of the glass yarn is 0.50 to 0.80 N/tex; and (iii) the number of filaments slipping to more than twice the average yarn width when measuring 180 m is 3 or less, The dielectric constant of the glass yarn is less than 5.0 at a frequency of 10 GHz, The twist interval length of the glass yarn is 1.8 to 10.0 cm, and The glass yarn has a twist interval length difference index of 0.7 or less, wherein the twist interval length difference index is a value obtained by dividing the difference between the maximum twist interval length and the minimum twist interval length by the average twist interval length. 17. The method for manufacturing glass cloth according to claim 16, wherein the glass cloth comprises the glass yarn satisfying the following conditions: (i) TEX is 1.5 to 12; (ii) a breaking strength of 0.53 to 0.79 N/tex; and (iii) The number of filaments which slipped to twice or more of the average yarn width when measuring 180 m is 2 or less. 18. The method for manufacturing glass cloth according to claim 16, wherein the glass cloth comprises the glass yarn satisfying the following conditions: (i) TEX is 2.0 to 11; (ii) a breaking strength of 0.57 to 0.78 N/tex; and (iii) The number of filaments which slipped to twice or more of the average yarn width when measuring 180 m was 1 or less. 19. The method for manufacturing glass cloth according to claim 16, wherein the glass cloth comprises the glass yarn satisfying the following conditions: (i) TEX is 1 to 7; (ii) a breaking strength of 0.60 to 0.77 N/tex; and (iii) The number of filaments which slipped to twice or more of the average yarn width when measuring 180 m was 0. 20 . The method for producing glass cloth according to claim 16 , wherein the glass yarn has a TEX of 1 to 7. 21 . The method for producing glass cloth according to claim 16 , wherein the number of glass filaments constituting the glass yarn is 30 to 120. 22 . The method for producing glass cloth according to claim 16 , wherein the twist interval length difference index is 0.6 or less. 23 . The method for producing glass cloth according to claim 16 , wherein the twist interval length difference index is 0.5 or less. 24 . The method for producing glass cloth according to claim 16 , wherein the twist interval length difference index is 0.4 or less. 25 . The method for producing glass cloth according to claim 16 , wherein the glass yarn has a density of 2.2 g/cm ³ or more and less than 2.5 g/cm ³ . 26 . The method for producing glass cloth according to claim 25 , wherein the density of the glass yarn is 2.25 g/cm ³ or more and 2.4 g/cm ³ or less. 27 . The method for producing glass cloth according to claim 16 , wherein the elastic modulus of the glass yarn is 50 to 70 GPa. 28 . The method for producing glass cloth according to claim 16 , wherein the elastic modulus of the glass yarn is 50 to 63 GPa. 29. The method for producing glass cloth according to any one of claims 16 to 19, wherein the glass yarn having a length of 10,000 m or more is used as a target, When a measurement range of 180 m in the longitudinal direction is selected at five different locations, the number of filaments that slipped to twice or more of the average yarn width is 3 or less in each of the five measurement ranges. 30. The method for producing glass cloth according to any one of claims 16 to 19, wherein the glass yarn having a length of 50,000 m or more is used as a target, When a measurement range of 180 m in the longitudinal direction is selected at seven different locations, the number of filaments that slipped to twice or more of the average yarn width is three or less in each of the seven measurement ranges. 31. The method for producing glass cloth according to any one of claims 16 to 19, wherein the glass yarn having a length of 100,000 m or more is used as a target, When a measurement range of 180 m in the longitudinal direction is selected at 10 different locations, the number of filaments that slipped to more than twice the average yarn width is 3 or less in each of the 10 measurement ranges. 32. A glass yarn, wherein: (i) TEX is 1 to 13; (ii) a breaking strength of 0.50 to 0.80 N/tex; and (iii) the number of filaments slipping to more than twice the average yarn width when measuring 180 m is 3 or less, The dielectric constant of the glass yarn is less than 5.0 at a frequency of 10 GHz, The twist interval length of the glass yarn is 1.8 to 10.0 cm, and The glass yarn has a twist interval length difference index of 0.7 or less, wherein the twist interval length difference index is a value obtained by dividing the difference between the maximum twist interval length and the minimum twist interval length by the average twist interval length. 33. The glass yarn according to claim 32, wherein: (i) TEX is 1.5 to 12; (ii) a breaking strength of 0.53 to 0.79 N/tex; and (iii) The number of filaments which slipped to twice or more of the average yarn width when measuring 180 m is 2 or less. 34. The glass yarn according to claim 32, wherein (i) TEX is 2.0 to 11; (ii) a breaking strength of 0.57 to 0.78 N/tex; and (iii) The number of filaments which slipped to twice or more of the average yarn width when measuring 180 m was 1 or less. 35. The glass yarn according to claim 32, wherein (i) TEX is 1 to 7; (ii) a breaking strength of 0.60 to 0.77 N/tex; and (iii) The number of filaments which slipped to twice or more of the average yarn width when measuring 180 m was 0. The glass yarn according to any one of claims 32 to 35, wherein the TEX is 1 to 7. 37. The glass yarn according to any one of claims 32 to 35, wherein the number of glass monofilaments constituting the glass yarn is 30 to 120. The glass yarn according to claim 32 , wherein the twist interval length difference index is 0.6 or less. The glass yarn according to claim 32 , wherein the twist interval length difference index is 0.5 or less. 40. The glass yarn according to claim 32, wherein the twist interval length difference index is 0.4 or less. The glass yarn according to any one of claims 32 to 35, which has a density of 2.2 g/cm ³ or more and less than 2.5 g/cm ³ . 42. The glass yarn according to any one of claims 32 to 35, which has an elastic modulus of 50 to 70 GPa. 43. The glass yarn according to any one of claims 32 to 35, which has an elastic modulus of 50 to 63 GPa. 44. The glass yarn according to any one of claims 32 to 35, wherein the glass yarn has a length of 10,000 m or more. When a measurement range of 180 m in the longitudinal direction is selected at five different locations, the number of filaments that slipped to twice or more of the average yarn width is 3 or less in each of the five measurement ranges. 45. The glass yarn according to any one of claims 32 to 35, wherein the glass yarn has a length of 50,000 m or more. When a measurement range of 180 m in the longitudinal direction is selected at seven different locations, the number of filaments that slipped to twice or more of the average yarn width is three or less in each of the seven measurement ranges. 46. The glass yarn according to any one of claims 32 to 35, wherein the glass yarn has a length of 100,000 m or more. When a measurement range of 180 m in the longitudinal direction is selected at 10 different locations, the number of filaments that slipped to more than twice the average yarn width is 3 or less in each of the 10 measurement ranges.