CN113529238B

CN113529238B - Roll-shaped long glass cloth, prepreg, and printed wiring board

Info

Publication number: CN113529238B
Application number: CN202010235385.5A
Authority: CN
Inventors: 远藤正朗; 佐藤滋; 松田一徹; 世古宗泉
Original assignee: Asahi Kasei Corp
Current assignee: Asahi Kasei Corp
Priority date: 2020-03-30
Filing date: 2020-03-30
Publication date: 2022-12-30
Anticipated expiration: 2040-03-30
Also published as: CN113529238A

Abstract

A long roll-shaped glass cloth, a prepreg, and a printed wiring board are provided. Provided is a glass cloth which, even if it is a glass cloth having a small elastic modulus, can suppress deformation of a fabric structure such as wrinkles and can reduce variation in dimensional change when it is produced into a printed wiring board. A long roll glass cloth which is constituted by using glass yarns comprising a plurality of glass filaments as warp yarns and weft yarns and is wound on a winding core tube, and satisfies the following conditions: 1) the thickness of the glass cloth is 8 to 100 μm, 2) the winding hardness is 45 to 70, and 3) the neck-in amount is-0.5 to less than 0.1%.

Description

Roll-shaped long glass cloth, prepreg, and printed wiring board

Technical Field

The present invention relates to a long roll glass cloth, a prepreg, and a printed wiring board.

Background

Printed wiring boards for electronic devices are generally manufactured by the following method: a substrate such as a glass cloth is impregnated with a thermosetting resin such as an epoxy resin or a polyphenylene ether resin, and dried to form a prepreg, one or more sheets of the prepreg are stacked, and a copper foil is stacked as necessary, followed by heating and pressure molding to form a laminate, and then a circuit pattern including a copper foil is formed.

In recent years, with the increase in performance and high-speed communication of information terminals such as smartphones, printed wiring boards have been significantly reduced in dielectric constant and dielectric loss tangent. Various low dielectric glass cloths have also been proposed as glass cloths constituting printed wiring boards (for example, patent documents 1 to 6).

In the low dielectric glass cloth disclosed in patent documents 1 to 6, B in glass is increased as compared with E glass cloth which has been generally used in the past ₂ O ₃ The content ratio of (A) realizes a low dielectric constant and a low dielectric loss tangent.

Documents of the prior art

Patent literature

Patent document 1: japanese patent No. 4269194

Patent document 2: japanese laid-open patent publication No. 2010-508226

Patent document 3: international laid-open publication No. 2016/175248

Patent document 4: U.S. Pat. No. 5,9556060

Patent document 5: international publication No. 2017/187471

Patent document 6: TWI1591041 publication

Disclosure of Invention

Problems to be solved by the invention

However, if B in the glass is increased to make the glass cloth low in dielectric constant ₂ O ₃ The content ratio tends to lower the elastic modulus of the glass and soften the texture of the glass cloth. The elastic modulus of the E glass cloth is about 74GPa, while the elastic modulus of NE glass cloth manufactured by ritnshowa corporation is 64GPa (disclosed in the homepage of ritnshowa corporation), and the elastic modulus of L glass cloth manufactured by asahi chemical corporation is 61GPa by pulse-echo superposition, and the elastic modulus of these low dielectric glass cloths is smaller than that of the E glass cloth.

Here, the glass cloth having a low elastic modulus is likely to be deformed in a fabric structure such as slack, distortion of texture, or wrinkles in a surface treatment process, a fiber opening process, a conveying process, and a winding process in the production of the glass cloth, and the winding quality is deteriorated. In addition, glass cloth having a small elastic modulus has the following problems: the problem of large dimensional variation in the formation of circuit patterns during the heat and pressure molding in the process of manufacturing printed wiring boards.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a glass cloth which, even when the glass cloth has a small elastic modulus, can suppress deformation of a fabric structure such as wrinkles (that is, has excellent roll quality) and has small variations in dimensional changes when the glass cloth is produced into a printed wiring board.

Means for solving the problems

The present inventors have conducted intensive studies to solve the above problems, and as a result, have found that a glass cloth wound around a core tube satisfying specific conditions is excellent in roll quality and the variation in dimensional change when a printed wiring board is produced is suppressed to be small, and have completed the present invention.

Namely, the present invention is as follows.

[1] A long rolled glass cloth which is composed of glass yarns containing a plurality of glass filaments as warp yarns and weft yarns and is wound on a winding tube, and the long rolled glass cloth satisfies the following conditions:

1) The thickness of the glass cloth is 8 to 100 μm,

2) A winding hardness of 45 to 70 inclusive,

3) The shrinkage is more than-0.5% and less than 0.1%.

[2] The long rolled glass cloth according to [1], wherein the glass cloth has an elastic modulus of 50GPa or more and 70GPa or less.

[3] The long rolled glass cloth according to [1], wherein the elastic modulus of the glass cloth is 50GPa or more and 63GPa or less.

[4] The long rolled glass cloth according to any one of [1] to [3], wherein the sum of the boron content and the phosphorus content is 5 mass% or more and 20 mass% or less.

[5] The long rolled glass cloth according to any one of [1] to [3], wherein the sum of the boron content and the phosphorus content is 6.5 mass% or more and 20 mass% or less.

[6] The long rolled glass cloth according to any one of [1] to [5], wherein the glass cloth has a thickness of 35 μm or more and 60 μm or less,

the winding hardness is 45 to 60 inclusive.

[7] The long rolled glass cloth according to any one of [1] to [5], wherein the glass cloth has a thickness of 8 μm or more and less than 35 μm,

the winding hardness is 50 or more and 65 or less.

[8] The rolled long glass cloth according to any one of [1] to [7], wherein a coefficient of variation in winding hardness calculated from each winding hardness measured at the following measurement points is 0.025 or less,

the measurement points are set at a position 80mm inward from one end in the width direction and at 200mm intervals within a range from the measurement point toward the other end to 80mm inward from the other end.

[9] The long rolled glass cloth according to [8], wherein the difference in winding hardness between adjacent measurement points is less than 2.

[10] A prepreg, having:

[1] the long roll-like glass cloth according to any one of [1] to [9], and

a matrix resin composition.

[11] A printed wiring board having the prepreg according to [10 ].

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, even if the elastic modulus of the glass cloth is small, the glass cloth can be suppressed from being deformed in a fabric structure such as wrinkles, and is excellent in winding quality and small in variation in dimensional change in a process of manufacturing a printed wiring board.

Drawings

Fig. 1 is a view schematically showing an example of an apparatus for winding a long roll-shaped glass cloth according to the present embodiment.

Description of the reference numerals

11: winding core pipe

12: roller for rolling

13: expansion roller

14: glass cloth

Detailed Description

An embodiment of the present invention (hereinafter, referred to as "the present embodiment") will be described in detail below, but the present invention is not limited to the embodiment, and various modifications can be made without departing from the scope of the invention.

< roll-shaped long glass cloth >

The glass cloth of the present embodiment is a long rolled glass cloth wound around a winding core tube, which is configured by using glass yarns including a plurality of glass filaments as warp yarns and weft yarns. The rolled long glass cloth is also called a glass cloth roll.

Further, the long rolled glass cloth of the present embodiment satisfies:

1) The thickness of the glass cloth is 8 to 100 μm,

2) The winding hardness is 45-70 inclusive,

3) The shrinkage is more than-0.5% and less than 0.1%.

The long rolled glass cloth of the present embodiment is free from deformation of the fabric structure such as wrinkles occurring at the time of winding, is excellent in winding quality, and can reduce variation in dimensional change in the process of manufacturing a printed wiring board using the glass cloth wound around the glass cloth. The reason is considered to be that the glass cloth roll satisfies the conditions 1) to 3) described above, thereby reducing deformation occurring before the glass cloth roll is rolled, and suppressing deformation occurring at the time of unwinding.

The thickness of the long rolled glass cloth of the present embodiment is 8 μm or more and 100 μm or less, preferably 8 μm or more and 70 μm or less, and more preferably 8 μm or more and 50 μm or less.

In order to realize the reduction in thickness and the increase in density of a printed wiring board due to the high functionality, the size, and the weight reduction of a digital device, it is necessary to reduce the thickness of a glass cloth to 100 μm or less.

The thickness is preferably small from the viewpoint of thinning and densification of the printed wiring board, but the lower limit of the thickness is 8 μm from the viewpoint of strength.

The thickness of the long rolled glass cloth of the present embodiment is: thickness of the glass cloth constituting the layer of the roll.

The neck-in amount of the long rolled glass cloth of the present embodiment is-0.5% or more and less than 0.1%. The neck-in is preferably-0.4% or more and less than 0.1%, more preferably-0.3% or more and 0.05% or less, still more preferably-0.2% or more and 0.05% or less, and still more preferably-0.1% or more and 0% or less.

The necking-in of the glass cloth refers to the following phenomenon: in the step of winding the glass cloth around the winding core tube, the warp yarns are stretched under the winding tension and the weft yarns are contracted under the influence of the stretching, so that the compressive stress acts in the width direction.

Here, the "neck-in amount" in the present embodiment means: width W of glass cloth under no tension _o And the width W of the glass cloth on the take-up shaft _a A value obtained by the following formula (1).

Reduction (%) = (W) _a -W _o )/W _o ×100···(1)

Specifically, the neck-in can be measured by the method described in examples.

When the neck-in amount is less than 0.1%, the weft yarn maintains an original undulated state or a moderately stretched state, and the warp yarn is also restricted by the weft yarn, so that the undulated state is nearly uniform in the width direction, and therefore, a glass cloth excellent in dimensional stability is obtained.

Further, by setting the neck-in amount to-0.5% or more, the warp yarn undulation is not excessively increased and is maintained in a shape close to the original undulated state, so that the glass cloth can be densely laminated and the wound state is easily made tight.

By setting the neck-in amount to-0.5% or more and less than 0.1%, the warp and weft undulations of the glass cloth become uniform, and the wound state becomes a tightly laminated state.

Further, by setting the neck-in amount to-0.5% or more and less than 0.1%, the deformation of the glass cloth before the winding of the glass cloth, for example, in the weaving step, the fiber opening step, the surface treatment step and the like can be eliminated, and therefore, the glass cloth having a uniform fabric structure can be produced.

In a step of impregnating a glass cloth with a thermosetting resin and drying the resin to form a prepreg, forming a laminate using the prepreg, and then forming a circuit pattern including a copper foil, the glass cloth having a uniform fabric structure and a uniform undulation structure can reduce variations in dimensional changes in the step.

Examples of the method for adjusting the neck-in amount of the long rolled glass cloth to-0.5% or more and less than 0.1% include: a method of adjusting a winding method in a step of winding the glass cloth around the winding core tube (specifically, a method of adjusting a winding tension, a method of adjusting a pressing pressure, a method of spreading the glass cloth with a spreader roll or the like immediately before winding, a method of making a material of the roll be a rubber-like elastic body having rubber elasticity, and the like); a method of adjusting the warp and weft relief structure and SS characteristics by adjusting the type of yarn used for the glass cloth, the fabric density, the yarn width, and the like; a method of adjusting the type and amount of the silane coupling agent applied to the glass cloth to adjust the friction coefficient of the glass cloth; a method of adjusting the texture of the glass cloth; and a method of appropriately combining these methods.

The draw-down amount of the long rolled glass cloth of the present embodiment is preferably the same level throughout the entire roll from the inner layer to the outer layer of the roll, that is, from the start portion to the end portion of the roll. The difference between the neck-in amount on the inner layer side and the neck-in amount on the outer layer side is preferably 0.2% or less, more preferably 0.1% or less, and still more preferably 0.05% or less. The lower limit of the difference in the amount of necking-down is preferably 0%, but may be more than 0%.

Here, the inner layer of the roll means: the outer layer of the roll, starting from half the thickness of the layer of the long rolled glass cloth and going to the inside, is: from half the thickness of the layer of the long rolled glass cloth to the outermost layer. More specifically, for example, when the diameter of the core tube of the coil is 100mm and the diameter of the entire coil including the diameter of the core tube is 300mm, the inner layer is formed when the diameter exceeds 100mm and is 200mm or less, and the outer layer is formed when the diameter exceeds 200mm and is 300mm or less.

As a method for measuring the difference in the neck-in amount between the inner layer side and the outer layer side of the long rolled glass cloth, there are methods 1) to 6) below.

1) The length of the outermost layer of the glass cloth roll in the width direction was measured. At this time, the measurement is taken asA length W in the width direction in a direction perpendicular to the longitudinal direction (also referred to as MD direction) _a One end of the measured portion is marked.

2) Measuring the length W in the width direction of the marked position in 1) above without slack at the time of withdrawing about 2m of the glass cloth from the glass cloth roll _o 。

3) The neck-in was obtained by equation (1).

4) The measurements 1) to 3) above were repeated 5 times using the same glass cloth roll, and the average value thereof was defined as the neck-in on the outer layer side.

5) Then, the glass cloth was unwound to a position 1/4 of the thickness of the layer of the first glass cloth roll, and the length in the width direction of the position was measured. The above 1) to 4) were similarly performed as the neck-in amount on the inner layer side.

6) The difference between the inner shrinkage and the outer shrinkage is determined from the outer shrinkage and the inner shrinkage.

In order to prevent a negative value of tensile stress acting in the tangential direction inside the roll, that is, inside the outermost layer of the roll, when the glass cloth is wound, the winding tension is generally decreased as the roll diameter is increased as compared with when the roll diameter at the beginning of winding is small. Therefore, the neck-in amount tends to be different between the inner layer side and the outer layer side, and the undulation state of the warp and weft tends to be different between the inner layer side and the outer layer side.

In particular, glass cloth having a smaller elastic modulus and a softer texture tends to be deformed such as wrinkles due to the influence of negative tensile stress acting inside the roll, and therefore, the difference in winding tension according to the roll diameter needs to be increased, and the difference in the amount of contraction between the inner layer portion and the outer layer portion of the roll tends to be further increased.

However, if the undulation state of the warp and weft is different between the inner layer portion and the outer layer portion of the roll, the printed wiring board manufactured by the inner layer portion of the roll and the printed wiring board manufactured by the outer layer portion of the roll are different in the dimensional stability effect of the glass cloth. That is, the variation in the size of the printed wiring board manufactured from the same roll of glass cloth becomes large.

According to the long roll-shaped glass cloth of the present embodiment, the draw-down amount can be made to be equal from the inner layer to the outer layer of the roll, and the undulation structures of the inner layer portion and the outer layer portion of the roll can be made to be equal and uniform. Therefore, it is possible to reduce the variation in the dimensional change of the printed wiring board manufactured from the same roll.

The winding hardness of the long rolled glass cloth of the present embodiment is 45 or more and 70 or less, preferably 46 or more and 65 or less, more preferably 47 or more and 64 or less, and further preferably 48 or more and 63 or less.

The winding hardness in the present embodiment is as follows: the average value of the winding hardness was determined by measuring 3 points in the width direction using a model SCHMIDT control instruments HP-10 durometer manufactured by Hands Schmidt & Co GmbH Schichhtstr, wherein the 3 points are: 2 points located 80mm inward from both ends and 1 point located at the center in the width direction. The winding hardness in the present embodiment is a value measured on the outermost surface layer surface.

By setting the winding hardness to 45 or more, the glass cloth is densely laminated when wound around the winding core tube, 1) the compressive stress in the radial direction sufficiently acts even on the outer layer side of the roll, 2) the same tensile stress acts on the entire layer in the tangential direction, and 3) the deformation of the fabric structure is less likely to occur in the winding step, the deformation due to the redistribution of stress or the like does not occur in storage, and the generation of the deformation can be suppressed in the normal tensile stress range also in the unwinding step. The reason for the above 3) is assumed to be: the layers of the glass cloth are mutually constrained, so that the glass cloth cannot move in the roll.

Due to the reasons 1) to 3) described above, a glass cloth having a uniform fabric structure can be obtained when the prepreg is coated.

By setting the winding hardness to 70 or less, the difference in tensile stress acting in the tangential direction between the inner layer portion and the outer layer portion of the roll can be suppressed to be small, and a glass cloth excellent in uniformity over the entire length of the long glass cloth in the roll shape can be obtained.

The winding hardness can be adjusted to 45 to 70 inclusive by adjusting the winding tension in the step of winding the glass cloth, adjusting the pressing pressure, expanding the glass cloth with an expanding roller or the like immediately before winding, and winding the glass cloth densely.

The long rolled glass cloth of the present embodiment preferably has a thickness of 8 μm or more and less than 35 μm and a winding hardness of 50 or more and 65 or less.

When the thickness of the glass cloth is 8 μm or more and less than 35 μm, the winding hardness is more preferably 51 or more and 64 or less, and further preferably 52 or more and 63 or less.

Glass cloth having a thickness of 8 μm or more and less than 35 μm tends to be softer than glass cloth having a larger thickness, and the fabric structure is easily deformed by stress relaxation in a rolled state.

It is presumed that by setting the winding hardness to 50 or more, the interlayer pressure in the state of being wound in a roll shape is high, and the glass cloth layers are restrained from each other, and therefore, the occurrence of deformation can be suppressed.

The long rolled glass cloth of the present embodiment preferably has a thickness of 35 μm or more and 60 μm or less and a winding hardness of 45 or more and 60 or less.

When the thickness of the glass cloth is 35 μm or more and 60 μm or less, the winding hardness is more preferably 46 or more and 59 or less, and still more preferably 47 or more and 58 or less.

Since the winding density of the glass cloth having a thickness of 35 μm or more and 60 μm or less tends to be higher than that of a thin glass cloth having a thickness of 8 μm or more and less than 35 μm, the glass cloth is easily deformed by winding in the inner layer portion.

By setting the winding hardness to 60 or less, the internal stress acting in the tangential direction can be maintained even on the tensile side in the roll inner layer portion, and therefore, the glass cloth becomes uniform and does not deform due to wind-up or the like.

The burning weight loss of the long rolled glass cloth according to the present embodiment is preferably 0.1 mass% or more and 2.0 mass% or less, more preferably 0.13 mass% or more and 1.5 mass% or less, still more preferably 0.15 mass% or more and 1.3 mass% or less, and still more preferably 0.16 mass% or more and 1.2 mass% or less.

The burning weight loss of the glass cloth is an index for indirectly determining the amount of the coating layer containing the silane coupling agent applied to the surface of the glass cloth. The "weight loss by burning" referred to herein is a value measured by the method described in JISR 3420.

By setting the burn weight loss to 0.1% or more, sufficient adhesion to the matrix resin can be obtained in the production of the laminate, and moisture absorption resistance and heat resistance tend to be further improved.

Further, when the burn weight loss is 0.1% or more, the frictional force between the glass cloths is reduced, and the glass cloth layers stacked in the form of a take-up roll are easily moved, so that the deformation of the fabric structure at the time of taking-up the glass cloth is easily corrected and the fabric structure is easily made uniform.

When the burning weight loss is 2.0 mass% or less, the penetration of the resin into the glass cloth tends to be good. In addition, the burning weight loss is set to 2.0 mass% or less, so that the following tendency is exhibited: the friction between the glass cloths is suppressed to achieve a proper sliding property, and the deformation such as wrinkles due to shrinkage in the width direction on the glass cloth take-up roll can be suppressed.

The long glass cloth in roll form of the present embodiment is preferably a low dielectric glass cloth having an elastic modulus smaller than that of E glass, which can meet the demand for higher speed signals.

Examples of the glass cloth of the low dielectric glass include L glass cloth (specific elastic modulus 61 GPa), NE glass cloth (elastic modulus 64 GPa) and B ₂ O ₃ 15 to 30 mass% of SiO ₂ 45 to 60 mass% of P ₂ O ₅ Low dielectric glass cloth (elastic modulus 56 GPa) with a content of 2 to 8 mass%, and the like.

The elastic modulus of the long rolled glass cloth of the present embodiment is preferably 50GPa to 70GPa, more preferably 51GPa to 65GPa, still more preferably 52GPa to 63GPa, and yet more preferably 54GPa to 60 GPa.

Since the glass cloth of the low dielectric glass has a smaller elastic modulus than the E glass cloth and is more easily affected by stress from the outside, the deformation of the woven fabric tends to be easily corrected and made uniform by forming the long glass cloth in a roll form according to the present embodiment.

Further, since the above-mentioned low-dielectric and low-elastic-modulus glass cloth is soft and easily deforms the fabric structure such as slackening, twisting of texture, and wrinkling, and there is a large risk that such quality defects impair the performance, reliability, and safety of the printed wiring board, the long rolled glass cloth of the present embodiment is very useful in eliminating the deformation of the fabric structure.

In the long rolled glass cloth of the present embodiment, the sum of the boron content and the phosphorus content in the glass is preferably 5 mass% or more and 20 mass% or less, more preferably 6 mass% or more and 20 mass% or less, still more preferably 6.5 mass% or more and 20 mass% or less, and still more preferably 7 mass% or more and 10 mass% or less. The boron content and the phosphorus content are ratios (mass%) to the total amount of glass constituting the long rolled glass cloth.

The larger the sum of the boron content and the phosphorus content in the glass is, the more the dielectric constant and the dielectric loss tangent of the glass cloth tend to be reduced.

When the sum of the boron content and the phosphorus content is 5 mass% or more, the dielectric constant and the dielectric loss tangent are significantly reduced as compared with those of a laminated plate obtained using a normal E glass cloth, and therefore, the applicability to a large capacity and a high speed of data communication and signal processing is improved. For example, the dielectric constant of E glass is about 7, the dielectric constant when the sum of the boron content and the phosphorus content is 7.4% is about 4.8, and the dielectric constant when the sum of the boron content and the phosphorus content is 9.2% is about 4.4, and thus the dielectric constant tends to be small.

By setting the sum of the boron content and the phosphorus content to 20 mass% or less, the moisture absorption resistance and/or the heat resistance of the glass cloth can be maintained to the same extent as that of E glass having a boron content and a phosphorus content of about 2 mass%.

The sum of the boron content and the phosphorus content in the glass can be adjusted by the feed amount of the glass raw material containing boron and phosphorus in the process of producing the glass strand. In addition, in the step of producing glass yarn, the content of boron and phosphorus in the glass changes in the step of melting the glass raw material, and therefore the amount of feed can be appropriately adjusted in consideration of the amount of change.

The "boron content" and the "phosphorus content" in the glass cloth of the present embodiment are values obtained by ICP emission spectrometry.

Specifically, the boron content is a value obtained as follows: weighing a glass cloth sample, dissolving the glass cloth sample by using sodium carbonate, dissolving the glass cloth sample by using dilute nitric acid, fixing the volume, and measuring boron by using an ICP emission spectrometry to obtain the content of the sample.

The phosphorus content is a value determined as follows: weighing a glass cloth sample, heating and decomposing the glass cloth sample by using sulfuric acid, nitric acid and hydrofluoric acid, heating and dissolving the glass cloth sample by using dilute nitric acid, fixing the volume, and measuring phosphorus by using an ICP emission spectrometry to obtain the content in the sample.

In the examples of the present invention described later, ICP emission spectrum was measured using PS3520VDDI manufactured by Hitachi High-Tech Science Corporation.

The glass cloth of the present embodiment preferably has a coefficient of variation of the winding hardness, which is calculated from the winding hardness measured at a measurement point located 80mm inward from one end portion in the width direction and at a measurement point set at 200mm intervals within a range extending from the measurement point toward the other end portion to 80mm inward from the other end portion, of 0.025 or less

The coefficient of variation of the winding hardness is more preferably 0.021 or less, still more preferably 0.018 or less, and still more preferably 0.016 or less.

By setting the coefficient of variation of the winding hardness to 0.025 or less, the compressive stress acting in the radial direction and the tensile stress acting in the tangential direction of the rolled glass cloth act in the same manner in the width direction. Therefore, the following tendency is exhibited: even a low dielectric glass cloth having a small elastic modulus and a soft texture can be obtained, and a glass cloth having a uniform fabric structure without deformation can be obtained.

The coefficient of variation of the winding hardness is preferably 0 since the fabric structure of the glass cloth becomes uniform when it is small, but may exceed 0.

In the glass cloth of the present embodiment, it is preferable that the difference between adjacent measurement points among the winding hardnesses measured at the measurement points set at 200mm intervals in a range from the measurement point toward the other end portion to an inner side of 80mm from the other end portion in the width direction is less than 2.

The difference in winding hardness between the adjacent measurement points is more preferably less than 1, and still more preferably 0.

By setting the difference in winding hardness between adjacent measurement points to less than 2, it is possible to suppress variation in the longitudinal direction of the rolled glass cloth caused by a local difference in the width direction of tensile stress acting in the tangential direction in the low dielectric glass cloth having a small elastic modulus and a soft texture. Therefore, the following tendency is exhibited: the glass cloth in which wrinkles that easily occur in the roll inner layer portion are suppressed is obtained.

The difference in winding hardness between the adjacent measurement points is preferably 0 because the difference in winding hardness between the adjacent measurement points can make the glass cloth uniform, but may exceed 0.

The length of the long rolled glass cloth of the present embodiment is not particularly limited, and is usually 200m or more and 5,000m or less. When the length of the glass cloth is in the range of 200m to 5,000m, the effect of reducing the deformation of the fabric structure such as sag, distortion of texture, and wrinkles can be sufficiently obtained. A long glass cloth is preferable because it allows a large amount of prepreg to be continuously produced. On the other hand, a short length of the glass cloth is preferable because the size and weight of the rolled glass cloth are small and handling and storage properties are excellent.

The length of the long rolled glass cloth can be appropriately selected from the above range according to the use and processing purpose of the glass cloth.

The width of the glass cloth of the present embodiment is not particularly limited, and may be 500mm or more, 600mm or more, 700mm or more, 800mm or more, 900mm or more, or 1000mm or more, and may be 2000mm or less, 1900mm or less, 1800mm or less, 1700mm or less, 1600mm or less, 1500mm or less, 1400mm or less, or 1300mm or less.

In particular, the width is preferably 800mm or more and 1500mm or less. The width of the glass cloth is more preferably 900mm to 1400mm, and still more preferably 1000mm to 1300 mm.

When the width of the glass cloth is 800mm or more, the glass cloth is likely to be deformed in the uniformity of the fabric structure such as slackening and wrinkling in the weaving step, the opening step, the surface treatment step, and the like, but when the glass cloth is formed into a roll form in the present embodiment, the deformation is eliminated, and the glass cloth having a uniform fabric structure tends to be formed.

Further, by setting the width of the glass cloth to be in the range of 800mm to 1500mm, the effect of reducing the deformation of the fabric structure such as the slack, the distortion of the texture, and the wrinkles tends to be sufficiently obtained, and the prepreg can be produced by being supplied to a resin applicator which is commonly used in the production of a prepreg for a printed wiring board.

The winding core tube around which the long rolled glass cloth of the present embodiment is wound is preferably a winding core tube having a diameter of 100mm to 500mm. The diameter of the winding core tube is more preferably 130mm or more and 350mm or less, and still more preferably 150mm or more and 300mm or less.

When the diameter of the winding core tube is 100mm or more, the difference in stress acting on the glass cloth between the inner layer portion and the outer layer portion of the winding becomes small, and the effect of reducing the deformation of the fabric structure such as the slack, the distortion of the texture, and the wrinkle tends to be obtained more remarkably.

By setting the diameter of the winding core tube to 500mm or less, the diameter and weight of the long glass cloth in a roll shape can be reduced, and the handling property tends to be excellent.

The diameter of the winding tube can be appropriately selected from the above-mentioned diameter range according to the thickness, length, weight, and degree of uniformity required for the glass cloth.

The woven structure of the glass cloth is not particularly limited, and examples thereof include woven structures such as plain weave, basket weave, satin weave, and twill weave. Further, a mixed structure using different kinds of glass yarns may be employed. Among them, a plain weave structure is preferable.

< method for producing long strip rolled glass cloth >

As a method for producing a long glass cloth in a roll form according to the present embodiment, a method of adjusting a winding tension in a step of winding the glass cloth around a winding core tube is preferably mentioned.

In the process of winding the glass cloth around the core tube in the production of the long rolled glass cloth according to the present embodiment, for example, the glass cloth can be produced by using an apparatus in which the spreading roll 13 and the nip roll 12 are disposed immediately before the glass cloth 14 is wound around the core tube 11 as schematically shown in fig. 1.

In the production of rolled glass cloth, it is preferable to dispose an expander roll in the vicinity of the winding core tube or the winding roll immediately before the glass cloth is wound, and to pass the glass cloth through the expander roll. The expander roll can temporarily eliminate the neck-in of the glass cloth, and tends to achieve stable winding without depending on a process located further upstream from the expander roll.

The spreading roller is not particularly limited as long as it has a function of spreading the glass cloth in both end directions by bending the glass cloth and passing the glass cloth through the roller. As the expanding roller, for example: a type having a plurality of grooves inclined in the advancing direction of the web, such as a Zebra ROLLER type C and a Zebra ROLLER type D manufactured by MIYAKAWA ROLLER corporation, on the outer peripheral surface; a type in which rubbers having different friction coefficients and different hardnesses are alternately arranged in a diagonal direction along the advancing direction of the fiber web, such as a Zebra ROLLER type A and a B type manufactured by MIYAKAWA ROLLER, and a Composite firm ROLLER manufactured by Ming and rubber; types in which rubber provided on the outer periphery of the roller expands and contracts with rotation, such as Flat Expander Roll and Miravo Roll manufactured by mitsubishi corporation; a type of bent roll shaft such as KANSEN EXPANDER INDUSTRIAL co., an expanding roll made by LTD, a rubber expanding roll made by jinyang corporation; a type called a medium-high roll, which is a radial medium-high type (radial crown type) manufactured by Katsura Roller mfg.co., ltd. and in which the diameter of the central portion is larger than the diameters of both end portions; and so on.

In the winding of the rolled glass cloth according to the present embodiment, it is preferable to wind the glass cloth while applying a pressing pressure of 10N/m to 500N/m in the center direction of the winding shaft by a nip roll. The pressure applied by the roll is preferably 10 to 500N/m, more preferably 30 to 400N/m, and still more preferably 50 to 300N/m. The roll is not particularly limited as long as it is a roll generally used.

Since the winding is performed while applying a pressure of 10N/m or more by the roll, the entrainment of air into the layers of the wound glass cloth can be reduced, and a proper frictional force acts between the glass cloth on the outermost layer and the glass cloth on the adjacent inner layer side. Therefore, even when a compressive stress due to a winding tension acts on the glass cloth of the outermost layer, the outermost layer is restrained by the glass cloth located adjacent to and inside the outermost layer and is not easily moved, and therefore, the occurrence of winding wrinkles can be suppressed and the winding hardness can be adjusted.

The following is liable to occur by winding while applying a pressure of 500N/m or less by means of a roll: the quality problems such as fuzz generated by the local pressure action of the glass cloth are inhibited.

The material of the roll is preferably a rubber-like elastic body having rubber elasticity, and the rubber-like elastic body contains 1 or more selected from the group consisting of nitrile rubber, chloroprene rubber, ethylene-propylene rubber, silicone rubber, butyl rubber, styrene rubber, urethane rubber, hypalon rubber, fluorine rubber, natural rubber, and the like.

The roll is preferably a type a durometer having a shore a hardness of 30 or more and 80 or less. When the shore a hardness is 80 or less, the area on which the pressure acts becomes large, and therefore the following tendency is exhibited: the glass cloth stretched by the stretching roller can be wound while maintaining the stretched state. Further, by disposing the spreading roll and the rolling roll at a short interval, there is a tendency that: the cloth stretched by the stretching roller can be wound while maintaining the stretched state.

By setting the shore hardness to 30 or more, the roll itself can be suppressed from deforming with time, and therefore stable winding can be performed over a long period of time.

< sheet-like glass cloth >

The long rolled glass cloth of the present embodiment also includes a sheet-like glass cloth formed by unwinding from a rolled glass cloth. Further, the glass cloth may be continuously supplied to the production of the prepreg or the like while being unwound from the rolled glass cloth.

According to the present embodiment, a glass cloth having a low dielectric constant and a low dielectric loss tangent, which is less likely to be deformed such as slack, distortion of texture, or wrinkles, and thus has excellent handling properties and dimensional stability, can be provided.

< prepreg >

One of the embodiments is a prepreg including the long roll-shaped glass cloth of the embodiment and a matrix resin composition. The glass cloth is impregnated with a matrix resin.

By producing a prepreg using at least a part of the long rolled glass cloth of the present embodiment, a prepreg having excellent dimensional stability in a step of forming a laminate by heating and pressing the prepreg and a step of forming a circuit can be provided.

A prepreg manufactured using the long roll-shaped glass cloth of the present embodiment can be manufactured by a conventional method. For example, a resin-impregnated prepreg can be prepared by diluting a matrix resin such as an epoxy resin with an organic solvent to impregnate a glass cloth obtained by unwinding a roll-shaped glass cloth of the present embodiment with a varnish, and then volatilizing the organic solvent in a drying oven to cure the thermosetting resin to a B-stage state (semi-cured state).

As the matrix resin composition, in addition to the above epoxy resin, there can be mentioned: thermosetting resins such as bismaleimide resins, cyanate resins, unsaturated polyester resins, polyimide resins, BT resins, and functionalized polyphenylene ether resins; thermoplastic resins such as polyphenylene ether resins, polyether imide resins, liquid Crystal Polymers (LCP) of wholly aromatic polyesters, polybutadiene, and fluorine resins; and mixed resins thereof. From the viewpoint of improving dielectric characteristics, heat resistance, solvent resistance, and press moldability, a resin obtained by modifying a thermoplastic resin with a thermosetting resin can be used as the matrix resin composition.

As the matrix resin composition, a resin in which an inorganic filler such as silica and aluminum hydroxide is mixed; flame retardants such as bromine, phosphorus, and metal hydroxides; and a silane coupling agent; a heat stabilizer; an antistatic agent; an ultraviolet absorber; a pigment; a colorant; a lubricant, and the like.

< printed wiring board >

One of the embodiments is a printed wiring board manufactured using the prepreg of the embodiment, that is, including the prepreg of the embodiment. By manufacturing a printed wiring board using the prepreg of the present embodiment, a high-quality printed wiring board with an accurate wiring circuit can be provided.

Examples

The present invention will be specifically described below with reference to examples.

In examples and comparative examples, physical properties were measured by the following methods.

(1) Physical Properties of glass cloth

The physical properties of the glass cloth were measured according to JIS R3420, specifically, the thickness of the glass cloth, the mass of the warp and weft, the diameter of the filaments constituting the warp and weft, the number of filaments, and the fabric density of the warp and weft.

(2) Reduction of width of rolled glass cloth

Width W of glass cloth under no tension _o And the width W of the glass cloth on the take-up roll _a The reduction amount is obtained by the following formula (1).

Reduction (%) = (W) _a -W _o )/W _o ×100···(1)

Specifically, the neck-in amount was measured in the following 1) to 4).

1) The length of the outermost layer of the glass cloth roll in the width direction was measured. At this time, the length W in the width direction, which is the direction perpendicular to the MD direction, is measured _a One end of the measured portion is marked.

2) Measuring the marked position in 1) above without slack at the moment of withdrawing about 2m of glass cloth from the rollLength W in width direction _o 。

3) The neck-in was obtained by equation (1).

4) The measurements 1) to 3) above were repeated 5 times using the same roll of glass cloth, and the average value thereof was taken as the neck-in amount.

(3) Winding hardness of rolled glass cloth, variation rate of winding hardness, and difference in winding hardness between adjacent measurement points

Regarding the winding hardness, 3 points were measured in the width direction of the rolled glass cloth using a Schmidt & Co GmbH Schichtstr schhmt model schhmidt HP-10 durometer, and the average value was taken as the winding hardness of the rolled glass cloth, where the 3 points were: 2 points located 80mm inward from both ends and 1 point located at the center in the width direction.

The change rate of the winding hardness and the difference between the winding hardness at adjacent measurement points were also calculated using a model hardness tester model HP-10 of SCHMIDT control instruments manufactured by Hands Schmidt & Co GmbH Schichhtstr.

(4) Evaluation of dimensional stability

(test prepreg production)

The surface layer side 500m of the rolled glass cloth obtained in examples and comparative examples was divided into 3 pieces of glass cloth having a width of 430mm in the same direction as the winding direction, and 3 pieces of glass cloth having a width of 430mm and a length of 500m were obtained as the surface layer side a, the surface layer side b, and the surface layer side c, respectively. Here, the surface layer side 500m means 500m from the winding end point of the outermost surface layer.

The 500m inner layer side of the rolled glass cloth obtained in examples and comparative examples was divided into 3 pieces of glass cloth having a width of 430mm, and the 3 pieces of glass cloth having a width of 430mm and a length of 500m were set as inner layer side a, inner layer side b and inner layer side c, respectively. Here, the inner layer side 500m means: 500m between 550m from the winding start point of the winding core tube and 50m from the winding start point of the winding core tube.

Next, the 6 pieces of glass cloth obtained, that is, the surface layer side a, the surface layer side b, the surface layer side c, the inner layer side a, the inner layer side b, and the inner layer side c were each subjected to coating with a prepreg using an epoxy resin varnish to obtain 6 pieces of test prepregs, that is, the surface layer side a, the surface layer side b, the surface layer side c, the inner layer side a, the inner layer side b, and the inner layer side c. An epoxy varnish was prepared by mixing 80 parts by mass of a low-brominated bisphenol a epoxy resin, 20 parts by mass of a cresol novolac epoxy resin, 2 parts by mass of dicyandiamide, 0.2 part by mass of 2-ethyl-4-methylimidazole, and 100 parts by mass of 2-methoxy-ethanol. The prepreg coating was performed under the following conditions: the glass cloth was immersed in the epoxy varnish while being conveyed at a speed of 3m/min, and the excess varnish was scraped off by passing the glass cloth through a slit with a gap adjusted so that the resin content was 68 mass%, and then dried at a drying temperature of 170 ℃ for 1 minute and 30 seconds.

(test substrate preparation)

Using test prepregs prepared from different portions of a rolled glass cloth, the surface layer side a, the surface layer side b, the surface layer side c, the inner layer side a, the inner layer side b, and the inner layer side c, a test substrate, the surface layer side a, the surface layer side b, the surface layer side c, the inner layer side a, the inner layer side b, and the inner layer side c were prepared in the following manner.

Cutting the prepreg into 340mm × 340mm size, laminating 2 sheets of the prepreg, arranging copper foils with thickness of 12 μm on both surfaces, and heating at 195 deg.C and 40kgf/cm ² The test substrates were obtained by compression molding, i.e., a surface layer side a, a surface layer side b, a surface layer side c, an inner layer side a, an inner layer side b, and an inner layer side c.

(evaluation of dimensional stability)

The test substrate thus obtained was marked at intervals of 125mm at 3 vertical positions × 3 horizontal positions, i.e., at 9 positions in total. Then, the mark interval of the adjacent 2 marks at 6 positions is measured for the longitudinal direction and the lateral direction, respectively, to obtain a measured value α. Then, the copper foil was removed by etching treatment, heated at 170 ℃ for 30 minutes, and the mark interval was measured again to obtain a measured value β. The dimensional change rate value between 6 reference points in the warp direction and the weft direction is obtained by calculating the ratio of the difference between the measured value alpha and the measured value beta to the measured value alpha for the warp direction and the weft direction.

The dimensional change ratios described above were measured for 6 test substrates prepared from different portions of the rolled glass cloth, i.e., the surface layer side a, the surface layer side b, the surface layer side c, the inner layer side a, the inner layer side b, and the inner layer side c, to obtain dimensional change ratio values between a total of 36 reference points in each of the warp direction and the weft direction.

Next, the average value of the dimensional change rate values in the warp direction of 36 pieces obtained from the 6 test substrates, i.e., the surface layer side a, the surface layer side b, the surface layer side c, the inner layer side a, the inner layer side b, and the inner layer side c was obtained as the dimensional change rate in the warp direction. Further, the standard deviation of the 36 dimensional change rate values in the warp direction was obtained as the deviation of the dimensional change rate in the warp direction.

Similarly, the average value of the dimensional change rate values in the weft direction of 36 pieces was obtained as the dimensional change rate in the weft direction. Further, a standard deviation of 36 dimensional change rate values in the weft direction was obtained as a deviation of the dimensional change rate in the weft direction.

(5) Quality of rolled glass cloth and quality of rolled glass cloth at unwinding

Regarding the quality of the rolled glass cloth, appearance inspection was performed at the time of winding and after the end of winding, and the presence or absence of winding wrinkles and loose winding was confirmed. In the table, "o" indicates that there was no winding wrinkle or loose winding during and after winding.

Regarding the quality of the rolled glass cloth at the time of unwinding, appearance inspection of the unwound roll was performed to confirm the presence or absence of winding wrinkles and irregularities due to winding wrinkles. In the table, a circle indicates no winding wrinkle and no unevenness.

< example 1 >

As both the warp and weft, a yarn having an average filament diameter of 4.0. Mu.m, a filament number of 50, a twist number of 1.0Z and a weight per unit length of 1.44X 10 was used ^-6 kg/m glass yarn (elastic modulus 61GPa, boron content 7.35% and phosphorus content 0.02%), and an air jet loom was used to weave glass cloth with a fabric density of 95.0 warps/25 mm and 95.5 wefts/25 mm to obtain a grey cloth with a width of 1,350mm.

Desizing the grey cloth by heating at 400 ℃ for 24 hours, and then soaking the glass cloth in N-beta- (N-vinylbenzylaminoethyl) -gamma-aminopropyltrimethoxysilane serving as a silane coupling agent; SZ6032 (manufactured by Tollio Dow Corning Co., ltd.), followed by pressing, drying at 120 ℃ for 1 minute, splitting by high-pressure water jet, and width-processing to obtain a glass cloth A.

After the glass cloth A was spread by the spreading roll, the glass cloth A was wound around a winding core tube having a diameter of 240mm under conditions of an initial winding tension of 300N and a winding tension of 70% gradient rate (Taper rate) while applying a pressing force uniformly in the width direction to the winding roll by a rubber elastic roll having a Shore hardness of 30, to obtain a rolled glass cloth A having a thickness of 15 μm, a burning weight loss of 0.89%, a width of 1,290mm and a length of 2,000m.

In the above-described winding process step, winding is performed by adjusting the winding tension and the extrusion pressure while checking the change in the winding hardness, and controlling the stress distribution and the winding hardness in the coil.

The rolled glass cloth a had a uniform roll shape without quality defects such as winding wrinkles and unwinding. The draw-in amount of the rolled glass cloth a was 0%, the average value of the winding hardness was 61, the variation rate of the winding hardness was 0.008, and the difference in the winding hardness was 1.

Further, when the glass cloth a in a roll form was unwound for producing a test substrate for evaluating dimensional stability, the glass cloth a was observed to be in a uniform state without winding wrinkles and irregularities in the entire layer up to the inner layer portion of the roll.

< example 2 >

As both the warp and weft, those having an average filament diameter of 5.0. Mu.m, a filament number of 100, a twist number of 1.0Z and a weight per unit length of 4.86X 10 were used ^-6 kg/m glass yarn (elastic modulus 61GPa, boron content 7.35% and phosphorus content 0.02%), and an air jet loom was used to weave glass cloth with a fabric density of 65.0 warps/25 mm and 67.0 wefts/25 mm to obtain a grey cloth with a width of 1,350mm. Desizing the grey cloth by heating at 400 ℃ for 24 hours, and then soaking the glass cloth in N-beta- (N-vinylbenzylaminoethyl) -gamma-aminopropyltrimethoxysilane serving as a silane coupling agent;SZ6032 (manufactured by Tooli Dow Corning Co., ltd.), followed by pressing, drying at 120 ℃ for 1 minute, splitting with high-pressure water jet, and then width-processing to obtain a glass cloth B.

After the glass cloth B was spread by the spreading roll, the glass cloth B was wound up on a winding core tube having a diameter of 240mm under a winding tension condition of an initial winding tension of 300N and a gradient rate of 70% by a rubber elastic roll having a Shore hardness of 30 while uniformly applying a pressing force to the winding roll in the width direction, and a rolled glass cloth B having a thickness of 28 μm, a burning weight loss of 0.60%, a width of 1,290mm, and a length of 2,000m was obtained.

The rolled glass cloth B had a uniform roll shape without quality defects such as winding wrinkles and loose rolls. The neck-in amount of the rolled glass cloth B was-0.08%, the average value of the winding hardness was 56, the fluctuation ratio of the winding hardness was 0.009, and the difference in the winding hardness was 1.

Further, when the glass cloth B in a roll form was unwound to produce a test substrate for evaluating dimensional stability, the observation revealed that the entire layer up to the inner layer portion of the roll was uniform without winding wrinkles or irregularities.

< comparative example 1 >

A glass cloth was produced in the same manner as in example 2 to obtain a glass cloth H.

The glass cloth H was wound around a winding core tube having a diameter of 240mm under a winding tension condition of an initial winding tension of 300N and a gradient rate of 20%, to obtain a rolled glass cloth H having a thickness of 28 μm, a burning weight loss of 0.60%, a width of 1,290mm, and a length of 2,000m.

In the rolled glass cloth H, slight winding wrinkles were generated from 500m to the outermost layer on the core side. The neck-in amount of the rolled glass cloth H was 0.19%, the average value of the winding hardness was 56, the variation rate of the winding hardness was 0.028, and the difference in the winding hardness was 3.

When the glass cloth H in a roll form was unwound to produce a test substrate for evaluating dimensional stability, the observation resulted in the presence of wrinkles, which were accompanied by irregularities and deeper than the winding wrinkles observed during winding, in the inner layer portion of the roll.

< comparative example 2 >

Glass cloth was produced in the same manner as in example 2 to obtain glass cloth I.

The glass cloth I was wound around a winding core tube having a diameter of 240mm under a winding condition of an initial winding tension of 200N and a gradient rate of 20%, to obtain a rolled glass cloth I having a thickness of 28 μm, a burning weight loss of 0.58%, a width of 1,290mm and a length of 2,000m.

The rolled glass cloth I has a uniform roll shape without quality defects such as winding wrinkles and loose rolls. The neck-in amount of the rolled glass cloth I was 0.16%, the average value of the winding hardness was 48, the variation rate of the winding hardness was 0.018, and the winding hardness difference was 2.

When the glass cloth I in a roll form was unwound to produce a test substrate for evaluating dimensional stability, observation was carried out, and as a result, slight winding wrinkles were present in the roll inner layer portion, although they were not observed at the time of winding.

< comparative example 3 >

Glass cloth was produced in the same manner as in example 2 to obtain glass cloth J.

The glass cloth J was wound around a winding core tube having a diameter of 240mm under a winding condition of an initial winding tension of 100N and a gradient rate of 20%, to obtain a rolled glass cloth J having a thickness of 28 μm, a burning weight loss of 0.60%, a width of 1,290mm and a length of 2,000m.

The rolled glass cloth J has a uniform roll shape without quality defects such as winding wrinkles and loose rolls. The draw-in amount of the rolled glass cloth J was 0.08%, the average value of the winding hardness was 43, the variation rate of the winding hardness was 0.009, and the difference in the winding hardness was 3.

When the glass cloth J in a roll form was unwound to produce a test substrate for dimensional stability evaluation, the observation was made that slight winding wrinkles were present in the inner layer portion of the roll, although not observed at the time of winding.

< example 3 >

As the warp and weft, the average filament diameter was 5.0. Mu.m, the number of filaments was 200, the number of twists was 1.0Z, and the weight per unit length was 9.78X 10 ^-6 kg/m glass yarn (elastic modulus 61GPa, boron content 7.35% and phosphorus content 0.02%), and an air-jet loom was used to weave glass cloth with a fabric density of 52.5 warps/25 mm and 52.5 wefts/25 mm to obtain a grey cloth with a width of 1,350mm. Desizing the grey cloth by heating at 400 ℃ for 24 hours, and then soaking the glass cloth in N-beta- (N-vinylbenzylaminoethyl) -gamma-aminopropyltrimethoxysilane serving as a silane coupling agent; SZ6032 (manufactured by Tooli Dow Corning Co., ltd.), followed by pressing, drying at 120 ℃ for 1 minute, splitting with high-pressure water jet, and then width-processing to obtain a glass cloth C.

After the glass cloth C was spread by the spreading roll, the glass cloth C was wound around a winding core tube having a diameter of 240mm under winding tension conditions of an initial winding tension of 240N and a gradient rate of 70% by a rubber elastic roll having a Shore hardness of 30 while uniformly applying a pressing force to the winding roll in the width direction, to obtain a rolled glass cloth C having a thickness of 46 μm, a burning weight loss of 0.56%, a width of 1,290mm, and a length of 2,000m.

The rolled glass cloth C had a uniform roll shape without quality defects such as winding wrinkles and loose rolls. The draw-in amount of the rolled glass cloth C was 0%, the average value of the winding hardness was 48, the variation rate of the winding hardness was 0.009, and the difference in the winding hardness was 1.

Further, when the glass cloth C in a roll form was unwound for producing a test substrate for evaluating dimensional stability, the glass cloth C was observed to be in a uniform state without winding wrinkles and irregularities in the entire layer up to the inner layer portion of the roll.

< example 4 >

Glass cloth was produced in the same manner as in example 3 to obtain glass cloth D.

After the glass cloth D was spread by the spreading roll, the glass cloth D was wound around a winding core tube having a diameter of 240mm under a winding tension condition of an initial winding tension of 400N and a gradient rate of 70% by using a rubber elastic roll having a Shore hardness of 30 to uniformly apply a pressing force to the winding roll in the width direction, and a rolled glass cloth D having a thickness of 46 μm, a burning weight loss of 0.54%, a width of 1,290mm, and a length of 2,000m was obtained.

The rolled glass cloth D had a uniform roll shape without quality defects such as winding wrinkles and loose rolls. The neck-in amount of the rolled glass cloth D was-0.08%, the average value of the winding hardness was 53, the fluctuation ratio of the winding hardness was 0.007, and the difference in the winding hardness was 1.

Further, when the rolled glass cloth D was unwound for producing a test substrate for evaluating dimensional stability, the observation revealed that the entire layer up to the inner layer portion of the roll was uniform without winding wrinkles or irregularities.

< comparative example 4 >

Glass cloth was produced in the same manner as in example 3, and glass cloth K was obtained.

The glass cloth K was wound around a winding core tube having a diameter of 240mm under a winding tension condition of an initial winding tension of 400N and a gradient rate of winding tension of 20%, to obtain a wound glass cloth K having a thickness of 46 μm, a burning weight loss of 0.57%, a width of 1,290mm and a length of 2,000m.

In the rolled glass cloth K, slight winding wrinkles were generated from 200m to the outermost layer on the core side. The neck-in amount of the rolled glass cloth K was 0.23%, the average value of the winding hardness was 53, the variation rate of the winding hardness was 0.022, and the winding hardness difference was 3.

When the glass cloth K in a roll form was unwound to produce a test substrate for evaluating dimensional stability, the observation resulted in the presence of wrinkles having deeper irregularities in the roll inner layer portion than the winding wrinkles observed during winding.

< comparative example 5 >

A glass cloth was produced in the same manner as in example 3 to obtain a glass cloth L.

The glass cloth L was wound around a winding core tube having a diameter of 240mm under a winding tension condition of an initial winding tension of 240N and a gradient rate of winding tension of 20%, to obtain a wound glass cloth L having a thickness of 46 μm, a burning weight loss of 0.56%, a width of 1,290mm and a length of 2,000m.

The rolled glass cloth L has a uniform roll shape without quality defects such as winding wrinkles and loose rolls. The draw-in amount of the rolled glass cloth L was 0.16%, the average value of the winding hardness was 48, the variation rate of the winding hardness was 0.021, and the difference in the winding hardness was 2.

When the glass cloth L in a roll form was unwound to produce a test substrate for dimensional stability evaluation, the observation was made that slight winding wrinkles were present in the inner layer portion of the roll, although they were not observed at the time of winding.

< comparative example 6 >

Glass cloth was produced in the same manner as in example 3 to obtain glass cloth M.

The glass cloth M was wound around a winding core tube having a diameter of 240mm under a winding tension condition of an initial winding tension of 100N and a gradient rate of winding tension of 20%, to obtain a wound glass cloth M having a thickness of 46 μ M, a burning weight loss of 0.56%, a width of 1,290mm and a length of 2,000m.

The rolled glass cloth M has a uniform roll shape without quality defects such as winding wrinkles and loose rolls. The neck-in amount of the rolled glass cloth M was 0.08%, the average value of the winding hardness was 44, the variation rate of the winding hardness was 0.018, and the winding hardness difference was 3.

When the glass cloth M in a roll form was unwound to produce a test substrate for dimensional stability evaluation, the observation was made that slight winding wrinkles were present in the inner layer portion of the roll, although not observed at the time of winding.

< example 5 >

As both the warp and weft, those having an average filament diameter of 5.0. Mu.m, a filament number of 200, a twist number of 1.0Z and a weight per unit length of 9.55X 10 were used ^-6 kg/m glass yarn (elastic modulus 56GPa, boron content 7.35% and phosphorus content 4.00%), and an air jet loom were used to weave glass cloth with a fabric density of 52.5 warps/25 mm and 52.5 wefts/25 mm to obtain a grey cloth with a width of 1,350mm. Desizing the grey cloth by heating at 400 ℃ for 24 hours, and then soaking the glass cloth in N-beta- (N-vinylbenzylaminoethyl) -gamma-aminopropyltrimethoxysilane serving as a silane coupling agent; SZ6032 (manufactured by Tooli Dow Corning Co., ltd.), followed by pressing, drying at 120 ℃ for 1 minute, splitting with high-pressure water jet, and then width-processing to obtain glass cloth E.

After the glass cloth E was spread by the spreading roll, the glass cloth E was wound around a winding core tube having a diameter of 240mm under a winding tension condition of an initial winding tension of 400N and a gradient rate of 70% by using a rubber elastic roll having a Shore hardness of 30 to uniformly apply a pressing force to the winding roll in the width direction, and a rolled glass cloth E having a thickness of 45 μm, a burning weight loss of 0.89%, a width of 1,290mm and a length of 2,000m was obtained.

The rolled glass cloth E had a uniform roll shape without quality defects such as winding wrinkles and loose rolls. The draw-in amount of the rolled glass cloth E was-0.08%, the average value of the winding hardness was 52, the variation rate of the winding hardness was 0.008, and the difference in the winding hardness was 1.

Further, when the rolled glass cloth E was unwound for producing a test substrate for evaluating dimensional stability, the observation revealed that the entire layer up to the inner layer portion of the roll was uniform without winding wrinkles or irregularities.

< example 6 >

As the warp and weft, those having an average filament diameter of 5.0 μm and filaments of the same diameter were usedNumber 100, twist number 1.0Z, weight per unit length 4.71X 10 ^-6 kg/m glass yarn (elastic modulus 56GPa, boron content 7.35% and phosphorus content 4.00%), and an air-jet loom was used to weave glass cloth with a fabric density of 65.0 warps/25 mm and 67.0 wefts/25 mm to obtain a grey cloth with a width of 1,350mm. Desizing the grey cloth by heating at 400 ℃ for 24 hours, and then soaking the glass cloth in N-beta- (N-vinylbenzylaminoethyl) -gamma-aminopropyltrimethoxysilane serving as a silane coupling agent; SZ6032 (manufactured by Tooli Dow Corning Co., ltd.), followed by pressing, drying at 120 ℃ for 1 minute, splitting with high-pressure water jet, and then width-processing to obtain a glass cloth F.

After the glass cloth F was spread by the spreading roll, the glass cloth F was wound up on a winding core tube having a diameter of 240mm under a winding tension condition of an initial winding tension of 300N and a gradient rate of 70% by a rubber elastic roll having a Shore hardness of 30 while applying a pressing force uniformly in the width direction to the winding roll, and a rolled glass cloth F having a thickness of 28 μm, a burning weight loss of 0.91%, a width of 1,290mm and a length of 2,000m was obtained.

The rolled glass cloth F had a uniform roll shape without quality defects such as winding wrinkles and loose rolls. The draw-down amount of the rolled glass cloth F was-0.08%, the average value of the winding hardness was 56, the variation rate of the winding hardness was 0.008, and the difference in the winding hardness was 1.

Further, when the glass cloth F in a roll form was unwound for producing a test substrate for evaluating dimensional stability, the glass cloth F was observed to be in a uniform state without winding wrinkles and irregularities in the entire layer up to the inner layer portion of the roll.

< example 7 >

As the warp and weft, the average filament diameter was 5.0. Mu.m, the number of filaments was 200, the number of twists was 1.0Z, and the weight per unit length was 10.88X 10 ^-6 kg/m glassGlass yarn (elastic modulus 74GPa, boron content 2.1% and phosphorus content 0.01%), and an air jet loom is used for weaving glass cloth with the fabric density of 52.5 warps/25 mm and 52.5 wefts/25 mm to obtain a grey cloth with the width of 1,350mm. Desizing the grey cloth by heating at 400 ℃ for 24 hours, and then soaking the glass cloth in N-beta- (N-vinylbenzylaminoethyl) -gamma-aminopropyltrimethoxysilane serving as a silane coupling agent; SZ6032 (manufactured by Tooli Dow Corning Co., ltd.), followed by pressing, drying at 120 ℃ for 1 minute, splitting by high-pressure water jet, and width-processing to obtain a glass cloth G.

After the glass cloth G was spread by the spreading roll, the glass cloth G was wound up on a winding core tube having a diameter of 240mm under a winding tension condition of an initial winding tension of 400N and a gradient rate of 70% by a rubber elastic roll having a Shore hardness of 30 while applying a pressing force uniformly in the width direction to the winding roll, and a rolled glass cloth G having a thickness of 44 μm, a burning weight loss of 0.17%, a width of 1,290mm and a length of 2,000m was obtained.

The rolled glass cloth G had a uniform roll shape without quality defects such as winding wrinkles and loose rolls. The neck-in amount of the rolled glass cloth G was 0.08%, the average value of the winding hardness was 55, the variation rate of the winding hardness was 0.022, and the winding hardness difference was 2.

Further, when the rolled glass cloth G was unwound for producing a test substrate for evaluating dimensional stability, the observation revealed that the whole layer up to the inner layer portion of the roll was uniform without winding wrinkles and irregularities.

< comparative example 7 >

Glass cloth was produced in the same manner as in example 7 to obtain glass cloth N.

The glass cloth N was wound around a winding core tube having a diameter of 240mm under a winding tension condition of an initial winding tension of 400N and a gradient rate of 20%, to obtain a rolled glass cloth N having a thickness of 44 μm, a burning weight loss of 0.16%, a width of 1,290mm, and a length of 2,000m.

In the rolled glass cloth N, slight winding wrinkles were generated from the core side 100m to the outermost layer. The neck-in amount of the rolled glass cloth N was 0.23%, the average value of the winding hardness was 54, the variation rate of the winding hardness was 0.029, and the winding hardness difference was 3.

When the glass cloth N in a roll form was unwound to produce a test substrate for evaluating dimensional stability, the inside of the roll was observed to have wrinkles with deeper irregularities than the winding wrinkles observed during winding.

[ test examples ]

The dimensional stability of the rolled glass cloths a to G and H to N obtained in examples 1 to 7 and comparative examples 1 to 7 was evaluated by the method described above. The results are shown in Table 1.

[ TABLE 1]

From the results shown in table 1, the rolled glass cloths a to G obtained in examples 1 to 7 exhibited the same dimensional stability in all of the inner layer portion and the outer layer portion of the roll and 3 positions in the width direction, and had small variations in the dimensional change rate.

Example 1A roll of glass cloth having a thickness of 15 μm, a neck-in of 0% and a winding hardness of 61,

Example 2 glass cloth roll B having a thickness of 28 μm, a neck-in of-0.08% and a winding hardness of 56,

Example 3A roll of glass cloth C having a thickness of 46 μm, a neck-in of 0% and a winding hardness of 48,

Example 4 glass cloth roll D having a thickness of 46 μm, a neck-in of-0.08%, and a winding hardness of 53

The dimensional stability was equivalent in all of the inner layer portion, the outer layer portion, and 3 positions in the width direction of the roll, and the variation in the dimensional change rate was small.

The glass cloth roll D of example 4, which had a high winding hardness, had a smaller dimensional change rate and a smaller variation in the dimensional change rate than the glass cloth roll C of example 3.

The dimensional change rate and the dimensional change rate of the glass cloth roll H having a draw-down amount of 0.19% in comparative example 1 and the glass cloth roll I having a draw-down amount of 0.16% in comparative example 2, which had the same thickness as the glass cloth roll B in example 2, were large and defective.

In comparative example 3, the glass cloth roll J having a winding hardness as low as 43 had large variations in the dimensional change rate and dimensional change rate, and was not satisfactory.

The glass cloth rolls K and L having the same thickness as the glass cloth rolls C and D of examples 3 and 4 and the draw-down amounts of 0.23% in comparative example 4 and 0.16% in comparative example 5 were large and poor in both the dimensional change rate and the dimensional change rate as compared with the glass cloth rolls C and D. In comparative example 6, the glass cloth roll M having a winding hardness as low as 44 had a large variation in the dimensional change rate and dimensional change rate, which was not satisfactory.

The glass cloth roll E of example 5 having a thickness of 45 μm, a neck-in of-0.08% and a winding hardness of 52 exhibited a smaller variation in the dimensional change rate than the glass cloth rolls C and D of examples 3 and 4 having the same thickness.

Glass cloth roll F of example 6, which had a thickness of 28 μm, a neck-in of-0.08% and a winding hardness of 56, exhibited less dimensional change rate variation than glass cloth roll B of example 2, which had the same thickness.

The glass cloth roll G of example 7, which had a thickness of 44 μm, a neck-in of 0.08% and a winding hardness of 55, exhibited a slightly larger variation in the dimensional change rate than the glass cloth rolls C, D and E of examples 3, 4 and 5, which had the same thickness.

In the glass cloth roll N having a thickness of 44 μm, a neck-in amount of 0.19% and a winding hardness of 54 in comparative example 7, the dimensional change rate and the dimensional change rate were large and poor compared with the glass cloth roll G having a neck-in amount of 0.08% in example 7.

Claims

1. A long rolled glass cloth which is composed of glass yarns containing a plurality of glass filaments as warp yarns and weft yarns and is wound on a winding tube, and the long rolled glass cloth satisfies the following conditions:

1) The thickness of the glass cloth is 8 μm or more and 100 μm or less,

2) The winding hardness is 45 to 70 inclusive,

3) The shrinkage is more than-0.5% and less than 0.1%.

2. A rolled long glass cloth according to claim 1, wherein a reduction amount of the rolled long glass cloth is-0.1% or more and 0% or less.

3. A long rolled glass cloth according to claim 1, wherein a difference between a draw-in amount on an inner layer side and a draw-in amount on an outer layer side of the long rolled glass cloth is 0% or more and 0.2% or less.

4. The rolled long glass cloth according to claim 1, wherein the burn weight loss of the rolled long glass cloth is 0.1 mass% or more and 2.0 mass% or less.

5. A rolled long glass cloth according to claim 1, wherein the diameter of the core tube is 100 to 500mm.

6. A rolled long glass cloth according to claim 1, wherein the glass cloth has an elastic modulus of 50GPa or more and 70GPa or less.

7. A rolled long glass cloth according to claim 1, wherein the glass cloth has an elastic modulus of 50GPa or more and 63GPa or less.

8. The rolled long glass cloth according to any one of claims 1 to 7, wherein the sum of the boron content and the phosphorus content is 5 mass% or more and 20 mass% or less.

9. The rolled long glass cloth according to any one of claims 1 to 7, wherein the sum of the boron content and the phosphorus content is 6.5 mass% or more and 20 mass% or less.

10. A rolled long glass cloth according to any one of claims 1 to 7,

the thickness of the glass cloth is 35 μm or more and 60 μm or less,

the winding hardness is 45 to 60 inclusive.

11. A rolled long glass cloth according to any one of claims 1 to 7,

the thickness of the glass cloth is more than 8 μm and less than 35 μm,

the winding hardness is 50 or more and 65 or less.

12. The rolled long glass cloth according to any one of claims 1 to 7, wherein a coefficient of variation in winding hardness calculated from each winding hardness measured at the following measurement points is 0.025 or less,

the measurement points are set at 80mm inward from one end in the width direction, and at 200mm intervals within a range from the measurement point toward the other end to 80mm inward from the other end.

13. The rolled long glass cloth according to claim 12, wherein a coefficient of variation of the winding hardness is 0.016 or less.

14. A rolled long glass cloth according to claim 12, wherein a difference in winding hardness between adjacent ones of said measurement points is less than 2.

15. A prepreg, having:

a long glass cloth roll as claimed in any one of claims 1 to 14, and

a matrix resin composition.

16. A printed wiring board having the prepreg of claim 15.