JPH08127959A - Inorganic fiber woven fabric for reinforcing - Google Patents

Abstract

PURPOSE: To obtain inorganic fiber woven fabric for reinforcing suitable as various inorganic fiber woven fabrics for reinforcing resins, especially printed wiring boards. CONSTITUTION: This inorganic fiber woven fabric for reinforcing is obtained by weaving warp and weft yarns comprising continuous inorganic filaments. The warp and weft yarns forming the woven fabric are uniformly opened and flattened without fuzzing and interstices among the respective warp and weft yarns forming the woven fabric are closed. Otherwise, the warp and weft yarns forming the woven fabric are uniformly opened, flattened and respectively napped to uniformly and thickly raise fine fuzz. Many traces of opened fibers caused by jetting high-pressure water jets are continuously formed along jetting loci of the high-pressure water jets covering the whole surface of the inorganic fiber woven fabric.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to various reinforcing inorganic fiber woven fabrics, and to provide a reinforcing inorganic fiber woven fabric suitable for reinforcing various resins and for printed wiring boards. is there.

[0002]

2. Description of the Related Art Inorganic fiber woven fabrics currently used are woven fabrics made of inorganic fibers such as glass fibers, carbon fibers or alumina fibers. In particular, glass fiber woven fabrics are widely used for resin reinforcement, but in recent years, they have been highly utilized for printed wiring boards. The inorganic fiber woven fabric as described above has an advantage that it has an excellent reinforcing effect because the content of the inorganic fibers is high.

However, when a printed wiring board is prepared by laminating an inorganic fiber woven fabric, there are drawbacks that delamination is likely to occur and the surface smoothness thereof is poor. That is, the fibers forming the woven fabric are, for example, glass fibers, which are usually composed of several hundred monofilaments having a filament diameter of 5 to 9 μ, and are made of continuous long fibers lightly twisted to maintain the yarn form. It is a weaving of warp and weft. Therefore, the degree of freedom of the inorganic fiber filaments forming the woven fabric is significantly restricted by twisting and weaving.

Further, in particular, the woven glass fiber cloth has a sizing agent mainly composed of starch and an oil agent applied at the time of spinning the glass fiber in a woven state. Therefore, in order to remove the sizing agent, heating deoiling is usually performed by heating at a temperature of about 400 ° C. for several tens of hours. Further, the surface of the glass fiber from which the sizing agent has been removed is subjected to a surface treatment such as various silane coupling agents in order to have an affinity with the resin used.

Therefore, the glass fiber filament in which the degree of freedom is remarkably restricted by twisting and weaving is attached to the surface though the heat setting effect by heating at high temperature for a long time and a very small amount. Due to the adhesion effect of the silane coupling agent, the filament bundles forming the warp and the weft are in a very good state of focusing.

As a result, the content of the inorganic fiber as the reinforcing material is high, and an excellent reinforcing effect can be obtained, but on the other hand, the inorganic fiber filaments forming the warp and the weft are mutually restrained, so that the warp and the weft are mixed with each other. There is a drawback that the surface rises at the crossing portion, and therefore when the substrate is impregnated with this resin, unevenness is caused on the surface due to the woven cloth, and the surface smoothness is not sufficient.

The above-mentioned problem of surface smoothness is important in a laminated board on which inorganic fiber woven fabrics are laminated. Particularly in the case of a printed wiring board, improvement of wiring density and miniaturization of patterns improve surface smoothness. Has become an important factor in the electronic component industry, and the surface smoothness of the current standard double-sided plate (1.6 mm thickness) is about 7 to 9 μ, but there is a growing demand to make it even smaller, about 3 μ. There is.

Not only that, but the warp threads and the weft threads forming the woven fabric are springs made by twisting hundreds of inorganic fibers, so that impregnation of the resin is difficult to proceed. This difficulty in impregnating the resin not only directly affects the production rate of the substrate on which the inorganic fibers are laminated, but also the mechanical and thermal characteristics It also affects the characteristics and is therefore not always sufficient for use in printed wiring boards and the like.

Furthermore, when the inorganic fiber woven fabrics are laminated, since the inorganic fibers are not oriented between the inorganic fiber woven fabrics to be laminated on each other, the adhesion between the two woven fabrics may be insufficient, and delamination may occur. .

Further, hole forming workability is an important characteristic required for a printed wiring board. This drilling process is an important step for forming holes for fixing components to be mounted on the board and holes for connecting circuits of each layer.
There are two methods of drilling, a punching process and a drilling process by drilling, and the punching process is naturally cheaper. The former is mainly carried out on a paper-phenolic board, but a board made of glass fiber woven cloth causes severe wear of the mold and the inner wall surface of the punched hole does not finish cleanly. It is being drilled.

However, even with the above-mentioned drilling process, abnormal cracks and chips may occur during drilling. That is, in the glass fiber woven cloth that has been conventionally used for reinforcement, the filament is not opened, and since the intersecting portions of the wefts and the gaps of the yarns between the intersecting portions are alternately present, the impregnation of the resin is prevented. Since the composition becomes non-uniform and the composition of the glass fiber woven fabric of the laminated plate and the resin is non-uniform, it is not always suitable for drilling, and the resistance is different between the warp and the weft crossing portion and the yarn gap portion, so the drilling The drilling speed at that time cannot be increased, cracks and chips easily occur, and the wall surface of the hole cannot be finished neatly.

The abnormality of the hole wall surface causes the incompleteness of the through hole portion, resulting in a decrease in the reliability of the circuit.
In this way, the drilling workability in the printed wiring board is
Depending on the printed wiring board, it is an important factor in the reliability of the circuit and also has a great influence on the productivity.

Further, in recent years, surface mounting technology (SMT) is becoming popular in electronic equipment mounting technology.
One of the greatest features of printed wiring boards for MT is that they have a large number of small-diameter (0.3 mm or less) via holes, and these via holes have a large plate thickness, that is, a large aspect ratio, and are highly accurate. An important issue is how to secure highly reliable and highly efficient drilling.

However, in the case of a conventional printed wiring board using a glass fiber woven cloth, in the case of drilling with a drill having a small diameter, due to the difference in resistance between the warp and the weft crossing portion and the thread gap portion between the crossing portions, There is a difficulty in positional accuracy and dimensional change, and it is necessary to improve the glass fiber. That is, when drilling a hole having a large aspect ratio with a small-diameter drill, the tip of the drill collides with the glass fiber, the hole on the back surface is displaced, and it is difficult to form a vertical via hole. Even if the via hole can be accurately formed, the substrate may undergo a dimensional change after the post-treatment such as etching and heat treatment, and as a result, the precise via hole may be deformed.

Conventionally, in order to improve the above-mentioned surface smoothness, delamination property, drill workability, hole position accuracy and dimensional stability of a small diameter drill, one of the constituent threads of the woven cloth is bulky processed. Alternatively, it has been attempted to use a non-woven fabric, and further to nip the woven fabric with rollers having different rotation speeds so as to exert a shearing force in the surface direction, and to improve the delamination of the inorganic fiber woven fabric, A method of raising a cloth by needle-punching the cloth (JP-A-57-10675).
No. 8), various methods have been tried.

When a non-woven fabric is used, it is effective in terms of surface smoothness and delamination, but the non-woven fabric is not constrained by the filaments being entangled with each other, and the form of the non-woven fabric is maintained by an adhesive, The adhesive must be compatible with the resin that impregnates the non-woven fabric, and since the non-woven fabric does not bind each other with filaments or threads, the content of inorganic fibers is less than half that of woven fabric (about 30%). Naturally, the reinforcing effect is also reduced, and in the case of non-woven fabrics, there is a drawback that the dimensional stability is poor, and in the case of using bulky processed yarn, uniform fluffing is not obtained and surface smoothness due to partial fluffing Is also impaired, and means for applying a shearing force in the surface direction with a roller is insufficient in terms of the effect to solve the above problems.

Further, when needle-punching is applied to the woven fabric in order to improve delamination, the difference between the weaving density of the woven fabric and the density of needle punching, the large difference between the needle punch shape and the woven fabric structure, and Due to the punching method, the constituent yarns are completely cut and broken, misalignment occurs, and many parts of the woven fabric that are not needle punched remain, so that uniform raising and fluff densification are practically impossible. Moreover, the breaking of the constituent yarns causes nonuniformity of the woven structure.
Further, in the needle punching process, the surface smoothness may be deteriorated because it consists of a punched portion and a non-punched portion.

[0018]

DISCLOSURE OF THE INVENTION The present invention can improve the lack of surface smoothness in a laminate using the above-mentioned conventional inorganic fiber woven cloth and the drawbacks of impregnating the woven cloth with a resin, and can also improve the inorganic fiber woven cloth. An object of the present invention is to provide an inorganic fiber woven fabric which can improve the delamination property when the fabric is a laminated plate, and at the same time, can improve the mechanical strength and the dimensional stability.

[0019]

According to a first aspect of the present invention, in a woven fabric obtained by weaving warp and weft yarns made of continuous long fibers, the warp yarns and the weft yarns forming the woven fabric do not fluff. Reinforcing inorganic fiber woven fabric that is uniformly opened and flattened, and that a large number of opened marks caused by the injection of the high-pressure water jet are formed continuously covering the entire surface of the woven fabric. Is.

According to a second aspect of the present invention, in a woven fabric obtained by weaving warp and wefts made of continuous long fibers, the warp and weft forming the woven fabric are uniformly spread and flattened. And the warps and wefts are raised individually, and minute fluff is densely densely formed, and there are many opened traces that cover the entire surface of the woven fabric and are caused by the jetting of the high-pressure water jet. It is a reinforced inorganic fiber woven fabric that is formed continuously.

[0021]

[Function] The inorganic fiber woven fabric of the present invention has a filament diameter of 5
Or 9 μ of an inorganic fiber monofilament having a size of 9 μm is woven as a constituent yarn, and various kinds of inorganic fibers such as glass fiber, carbon fiber or alumina fiber can be used.

The method for producing the reinforcing inorganic fiber woven fabric of the present invention will now be described. The inorganic fiber woven fabric is provided with a plurality of small rotary nozzles having a diameter of about 0.1 to 0.2 mm in the width direction of the woven fabric. Using high-pressure water jets arranged at equal intervals, the plurality of rotating nozzles are rotated (2000 to 3000 rpm) while being eccentric about 10 mm from the shaft center (pitch is within about 20 mm), and the plurality of nozzles are woven. Injection is performed by reciprocating 50 to 500 times per minute, preferably 100 to 300 times per minute in the width direction in the range of 10 to 20 mm.

The high-pressure water jet used in the present invention is preferably the one obtained by the "ultra-high-pressure water processing device" described in Japanese Patent Publication No. 57-22692, and its injection pressure can be adjusted appropriately. It has become. The high-pressure water jet described in the publication is a very thin high-pressure columnar jet flow jetted from a nozzle having a diameter of 0.1 to 0.4 mm,
It cuts stone and plastic.

If the nozzle pitch is larger than 20 mm, the radius of gyration of the nozzle becomes large, so that high-speed rotation becomes difficult due to the mechanical engineering characteristics, the injection density tends to be rough, and a uniform injection surface cannot be obtained. .

FIG. 3 is an enlarged view of the surface of the inorganic fiber woven fabric when the high pressure water jet is not applied. The warp and the weft forming the woven fabric are densely composed of a plurality of filaments. A void P is formed at the intersection of the warp and the weft.

On the other hand, FIG. 1 is an enlarged view of the surface of a woven inorganic fiber cloth subjected to a high-pressure water jet. The warp threads and the weft threads constituting the woven cloth are loosened and opened. Is recognized. Since the warp yarn and the weft yarn are loosened and opened, the yarn width is widened, and the void P shown in the intersection of the warp yarn and the weft yarn shown in FIG. 3 is eliminated.

Although not shown in FIG. 1 because the yarn width is widened and flattened, there are very few irregularities on the woven fabric surface due to the intersections of the warp yarns and the weft yarns, and therefore the smoothness of the woven fabric surface. Is also significantly improved. In order to open the warp and weft as shown in FIG. 1 and improve the surface smoothness, it is necessary to set the injection pressure of the high-pressure water jet to about 50 to 150 kg / cm ² . However, if the injection pressure is less than 50 kg / cm ² , sufficient opening cannot be obtained.

This high-pressure water jet has a diameter of 0.1 to
Since it is a very thin columnar flow that is jetted from a 0.2 mm nodule, the jetting energy is not diffused but is efficiently transmitted to the woven fabric surface as impact energy. Also, since the injection surface of the high-pressure water jet is a very small point,
In order to spray the woven cloth uniformly over the entire surface, it is necessary to arrange a plurality of nozzles in the width direction of the running woven cloth and move the nozzles at high speed.

Although FIG. 1 is not shown because it is an enlarged view, when the entire woven fabric is viewed, the traces of opening of the woven fabric due to the jetting of the high pressure water jet show the jet trajectory of the high pressure water jet. It is recognized that a large number are continuously formed along. This indicates that the surface of the woven fabric receives high impact energy of the high-pressure water jet, and it is understood that the entire woven fabric is uniformly spread. On the contrary, unless the impact energy is high enough to leave the jet trajectory of the high-pressure water jet, the good open state as shown by the inorganic fiber woven fabric of the present invention cannot be obtained. The high-pressure water jet has a plurality of jet loci, which are formed by continuously and regularly intersecting the entire surface of the woven fabric at a constant pitch.

FIG. 2 shows that the injection pressure of the high-pressure water jet is 150 to 1000 Kg / cm ² , preferably 200 to 500 Kg / cm ^2.
FIG. 4 is an enlarged view of the surface of the inorganic fiber woven fabric in the case of, where it can be seen that the woven fabric surface is uniformly raised, and that the warp and the weft are each loosened and opened.

As shown in FIGS. 1 and 2, when the warp yarns and the weft yarns constituting the inorganic fiber woven fabric are loosened to form an opened state, the yarns are flattened. Therefore, when this is impregnated with a resin liquid, the impregnation rate can be remarkably improved as compared with the prior art, and the impregnation resin can be made uniform. The impregnating property of the inorganic fiber woven fabric of the present invention is greatly improved as compared with the conventional product as shown in Examples. For example, in the case of a general-purpose product type of glass fiber woven fabric (WE18W type), Compared with, the impregnation time is shortened to less than 1/2, and in the case of the thin type (WE116E type), it is shortened to less than 1/4.

As described above, the glass fiber woven cloth having excellent impregnating properties while retaining the characteristics as a woven cloth has very excellent characteristics as a reinforcing material of resin as compared with the conventional product. Therefore, when the inorganic fiber woven fabric obtained as described above is used as a resin reinforcing material, since the woven fabric is not impaired in any way, it is excellent not only in mechanical strength but also in dimensional stability. At the same time, the surface can have a surface smoothness that has not been found in the past.

Further, as shown in FIG. 2, by increasing the injection pressure of the high-pressure water jet, the warp threads and the weft threads constituting the woven fabric can be loosened and opened, and the surfaces of the warp threads and the weft threads are made uniform. When the prepreg sheet is laminated by impregnating a resin on the woven inorganic fiber woven fabric that can be raised, the uniformly raised fibers exert an anchoring effect on the laminated sheet, and the peeling resistance effect is significantly improved. . In addition, the surface of the woven fabric is increased by the raised fibers to increase the resin impregnation rate, and the surface smoothness can be further improved by curing and molding.

Further, when the inorganic fiber woven fabric of the present invention is used for a printed wiring board, the resin impregnated into the woven fabric is good and uniform, so that the resin is filled even in the yarns constituting the inorganic fiber woven fabric. As a result, the filaments come into contact with each other, so that the adhesive strength at the interface between the inorganic fibers and the resin is increased, and the reinforcing effect of the inorganic fibers is improved. As a result, the dimensional stability of the laminated plate is improved. improves.

Further, since the internal structure of the laminated plate is homogenized, the shear stress does not change depending on the location and is uniform, the wall surface of the hole formed by drilling is also clean, and the rotation speed and feed of drilling There is also the advantage that the speed can be increased. Further, since the internal structure of the laminated plate is homogenized, it is possible to improve the hole position accuracy during drilling of the small-diameter via hole.

In the case of a glass fiber woven cloth, a high-pressure water jet is sprayed after heat deoiling for removing the sizing agent applied at the time of spinning, preferably after surface treatment with a silane coupling agent. A fine state is obtained. Further, the inorganic fiber woven fabric of the present invention is a simple operation of injecting a high-pressure water jet onto the inorganic fiber woven fabric, so that the work is also smooth, the impregnation rate of the resin into the inorganic fiber woven fabric is fast, and the prepreg is uniform. It is possible to improve the work efficiency of the process and the pressing process.

Further, according to the present invention, by adjusting the injection pressure of the high-pressure water jet, a woven fabric in which warp and weft yarns are opened or a woven fabric in which the surface of the warp yarns and weft yarns is raised in addition to the opened fabric Since it can be appropriately selected and obtained, it can be arbitrarily selected and manufactured according to the purpose and use of the inorganic fiber woven fabric.

[0038]

EXAMPLES In order to show the characteristics of various glass fiber woven fabrics according to the present invention, changes in the state of the woven fabric due to high-pressure water jet pressure, and surface smoothness and delaminating property of a laminate using the woven fabric are described. explain. The high-pressure water jet used in the examples was obtained by the "ultra-high pressure water processing device" described in Japanese Patent Publication No. 57-22692, and the injection conditions are as shown in Table 1.

[0039]

[Table 1]

The glass fiber woven fabrics used in the examples are all commercially available products "WE18WBZ ₂ " from Nitto Boseki Co., Ltd.
"WE116EBZ ₂ " (These woven glass fiber fabrics are surface-treated with epoxysilane after normal heat deoiling)
Table 2 shows these specifications.

[0041]

[Table 2]

Incidentally, the used yarn ECG7 of "WE18WBZ ₂ " shown in Table 2
5 1/0 and "WE116EBZ ₂ " use yarn ECE225 1/0 has the following specifications. The number of twists is 1Z (twist in the Z direction is once / 25m
m)

Next, the state change of the woven fabric of the glass fiber woven fabric according to the present invention due to the injection pressure of the high-pressure water jet (1)
Breathability test, (2) Tensile strength test, (3) Resin impregnation test,
(4) The data are shown by a resin content test, and further, the characteristics of a laminated plate prepared by using the glass fiber woven fabric are shown (5) the surface smoothness of the laminated plate, and (6) the delamination property of the laminated plate. (1) Breathability test Table 3 shows the breathability of a high-pressure water jet uniformly jetted from the surface of the woven glass fiber fabric.

[0044]

[Table 3]

As is clear from Table 3, the high-pressure water jet is applied to the woven cloth to loosen and open the warp and weft, thereby changing the air permeability. When the injection pressure is 200 Kg / cm ² or less, the voids are reduced due to the opening of the warp and the weft, and the air permeability is reduced. On the other hand, when it is 300 Kg / cm ² or more, the warp and the weft are raised, and high-pressure water passes between the warp and the weft to form a slight gap, thereby increasing the air permeability.

(2) Tensile Strength Test Table 4 shows the tensile strength of the glass fiber woven fabrics obtained in Examples 1 to 5.

[0047]

[Table 4]

As shown in Table 4, the woven fabric injected with the high-pressure water jet has a reduced tensile strength and an injection pressure of 500K.
In the case of g / cm ² , WE18WBZ ₂ is about 20% lower and WE116EBZ ₂ is about 15% lower than in the comparative example. It is considered that the filament is damaged and the filament itself is damaged by the injection of the high-pressure water jet, and the filament itself is broken in some cases.However, the high-pressure water jet of 500 kg / cm ² is used. The fact that it retains about 80% of the strength even after being jetted can be said to still sufficiently retain the characteristics as a woven fabric.

(3) Test of resin impregnation property The resin impregnation rate when a high-pressure water jet was applied to the same woven glass fiber cloth as above was measured, and the results shown in Table 5 were obtained. The resin used here is an epoxy resin having the following composition. Epicoat 1001 (Epoxy resin manufactured by Shell Chemical Co., Ltd.) 100 parts by weight Dicyandiamide 2 parts by weight Benzyldimethylamine 0.2 parts by weight Methyloxitol About 100 parts by weight

[0050]

[Table 5]

Incidentally, the resin impregnating property test method is a fixed area (10
cm × 10 cm) on a woven cloth, hang a certain amount (10 cc) of resin,
The time until the bubbles in the strands escape is measured. As is clear from Table 5, by injecting a high-pressure water jet, the warp and weft are opened, and the impregnation speed of the resin can be remarkably improved, and in particular, the impregnation speed can be significantly improved as the injection pressure is increased. To be Therefore, when the inorganic fiber woven fabric obtained by the high-pressure water jet treatment is used as a reinforcing material for the laminated plate, its production efficiency can be improved, and at the same production speed, the laminated plate having excellent characteristics due to the large impregnation speed. Can be obtained.

(4) Resin Content Test The resin content of a prepreg sheet obtained by impregnating a woven fabric with a resin when a high-pressure water jet was sprayed was tested, and the results shown in Table 6 were obtained. The woven cloth and resin are
It is the same as (1) and (3). In addition, the resin content is 39% of the blank resin content of the woven fabric “WE18WBZ ₂ ”.
The prepreg sheet shall be created under the same conditions as. The test method is according to JIS-R3420 / 5-3 "General test method for glass fiber".

[0053]

[Table 6]

As is clear from Table 6, the resin content is increased by increasing the injection pressure, and especially when the injection pressure is 200 Kg / cm ² or more, the warp and weft surfaces are raised, and therefore the resin content is higher than that of the blank. It is recognized that it will be even higher.

(5) Test of Surface Smoothness of Laminated Plate The laminated plate has a glass fiber woven cloth (WE18WB) on both sides.
Z ₂ ) is a high-pressure water jet treated prepreg, and six prepreg sheets made of glass fiber woven cloth that are not subjected to high-pressure water jet treatment are laminated inside, and copper foils ( The thickness is 18μ). The resin used for the prepreg sheet here is the same as the resin used in the (3) resin impregnation test, and the molding conditions for the laminate are a pressing pressure of 50 Kg / cm ² , a press cure temperature of 170 ° C., Prescure time is 90 minutes.

The surface smoothness conforms to JIS B0601 "Surface roughness measuring method". As shown in FIG. 4, 10 points on each dotted line in the 100 cm square sample surface (60 points in total)
Then, the length was set to 10 mm at one location, and measurement was performed using a universal shape measuring machine (Kosaka Laboratory Ltd., trade name SEF-IA type), and the results in Table 7 were obtained. For comparison, the results of the conventional product in which eight glass fiber woven fabrics similar to the above which are not subjected to the high pressure water jet treatment are laminated are also shown.

[0057]

[Table 7]

As is clear from Table 7, the injection pressure is 300 Kg /
In the case of using the glass fiber woven cloth of cm ^2, the average surface smoothness of the laminated plate is 3 μm or less, which is significantly less than half of the conventional product.

(6) Delamination test As the glass fiber woven fabric (WE18WBZ ₂ ), the glass fiber woven fabrics of Comparative Example and Examples 1 to 5 in the above (1) Breathability test were used. The prepreg sheets impregnated with the epoxy resin used in the resin impregnation test were laminated,
The laminated plate is formed under the same molding conditions as the above (5) Surface smoothness test of laminated plate. The delamination test was performed by supporting a short beam at three points according to ASTM D-2344, and the results shown in Table 8 were obtained.

[0060]

[Table 8]

The measuring method and sample size are as follows. Measuring method Span 12mm Load speed 2mm / min Sample size Thickness about 3.0mm Width about 10mm Length about 40mm

As is clear from Table 8, the injection pressure is 100 Kg / cm.
^When woven fabric of ² is used, it is about 5% compared to the conventional product, 300 to 500
The woven fabric of Kg / cm ² has an improved interlaminar shear force of about 30-40%, and it is recognized that the fibers raised by the injection of the high-pressure water jet contribute to the peelability.

[0063]

EFFECT OF THE INVENTION The reinforced inorganic fiber woven fabric of the present invention has a significantly improved impregnation with resin because the constituent yarns of the woven fabric are opened and flattened while the original properties of the woven fabric are retained. ,
In addition, the surface smoothness can be improved by crushing the intersecting portion of the warp and the weft. Furthermore, the constituent yarns of the woven fabric are opened, and the fluff that is uniformly raised is densely formed, whereby the impregnation property of the resin and the surface smoothness are further improved.

Further, the surface smoothness and delamination of the laminate using the woven fabric of the present invention can be remarkably improved as compared with the conventional products, and the resin can be sufficiently and uniformly impregnated into the inorganic fiber. Therefore, the internal structure of the laminated plate can be homogenized, processability during drilling and hole position accuracy of small diameter drills,
Furthermore, it is possible to improve the characteristics such as dimensional stability of the laminated plate.

[Brief description of drawings]

FIG. 1 is an enlarged view of a surface of an embodiment of the first invention.

FIG. 2 is an enlarged view of the surface of an embodiment of the second invention.

FIG. 3 is an enlarged view of the surface of a conventional product.

FIG. 4 is an explanatory diagram of a measuring method in a surface smoothness test.

Claims (2)

[Claims] 1. A woven fabric obtained by weaving a warp yarn and a weft yarn made of continuous inorganic long fibers, wherein the warp yarn and the weft yarn forming the woven fabric are uniformly spread and flattened without fluffing, In addition, a reinforcing inorganic fiber woven fabric is characterized in that a large number of opened marks due to the injection of a high-pressure water jet are continuously formed to cover the entire surface of the woven fabric. 2. A woven fabric obtained by weaving a warp yarn and a weft yarn made of continuous inorganic long fibers, wherein the warp yarn and the weft yarn forming the woven fabric are uniformly spread and flattened, and The weft and the weft are raised, respectively, and the minute fluff is uniformly densely formed, and a large number of open marks caused by the injection of the high-pressure water jet are formed continuously covering the entire surface of the woven cloth. Reinforcing inorganic fiber woven fabric characterized by being