JP3279049B2 - Unidirectional reinforced fabric and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a unidirectional reinforced fabric exhibiting excellent properties for use in a fiber-reinforced composite material and a method for producing the same, and particularly to a general structure, an elevated road pier and a floor slab. The present invention relates to a reinforcing base material optimal for reinforcing pillars, walls, etc. of a building, and a method of manufacturing the same.

[0002]

2. Description of the Related Art In recent years, the brittleness and durability of cement-based structures such as the destruction of bridges due to earthquakes, the generation of rust in reinforcement bars due to the neutralization of concrete, and the fatigue of reinforcing steel bars due to the rapid increase in traffic volume have been increasing in society. It is a problem. Of course, it is only necessary to update to a new one, but there is a problem that requires an enormous cost.

[0003] As a countermeasure, for example, in the case of a bridge slab, a reinforcing method of bonding a steel plate with an adhesive under a concrete slab or a fiber reinforced resin containing a carbon fiber base material is bonded. The method of making it reinforced is adopted. In particular, the latter method has been widely adopted because the reinforcing effect is high, the durability is excellent, and the reinforcing work is simple. As a carbon fiber substrate for reinforcement,
Carbon fiber yarns are unidirectionally oriented unidirectional fabrics, as most are reinforcements for longitudinal tensile fields. For this reason, unidirectional carbon fiber fabrics are used in which ordinary carbon fiber yarns are arranged as warp yarns and inexpensive glass yarns are used as the weft yarns.

[0004] In such a woven fabric, the surface of the woven carbon fiber yarn is uneven because the cross section of the woven carbon fiber yarn is elliptical, and the reinforcing fiber yarn of the warp yarn is bent by the tightening of the weft yarn. When reinforced with such a woven fabric, the surface of the woven fabric is uneven, so that the bonding area with the reinforcing body is small, so that sufficient adhesive strength cannot be obtained, and since the reinforcing fiber yarn is bent, the high carbon fiber has Tensile strength and elastic modulus are not sufficiently exhibited. Furthermore, when the tensile stress acts due to the resin-rich dents in the concave and convex portions, the fracture precedes with a low stress from that portion, and the resin impregnation is poor because the carbon fibers are gathered in an elliptical shape. In addition, there is a problem that there is a possibility that the whole is broken by a low tensile stress.

For the purpose of solving such problems, the present applicant has previously proposed a unidirectional carbon fiber flat yarn woven fabric (Japanese Patent Application No. 5-77967). According to the previous proposal, the use of flat carbon fiber yarns makes the woven fabric surface smooth, and the carbon fibers are uniformly present, so that a high adhesive effect can be obtained, and a resin-rich portion or a void portion can be obtained. Since there are no weak points, a high reinforcing effect can be obtained.

[0006] However, although the carbon fiber flat yarn constituting the woven fabric is a non-twisted yarn, the impregnating property of the resin is impaired by the adhesion of the fibers by the sizing agent, and the strength is caused by the orientation disorder due to the entanglement of the carbon fibers. There is a possibility that the carbon fiber may decrease, and the high strength and elastic modulus of the carbon fiber may not be sufficiently exhibited.

[0007] Further, since the woven fabric proposed in the preceding proposal is a very loose woven fabric having a low weaving density, when one warp yarn is alternately moved up and down by a heddle, a tension is applied to the weft yarn that has already been driven. As a result, there is a problem that the weft yarn is largely bent, and the weft yarn orientation is disturbed in the woven state, and at the same time, the warp yarn orientation cannot be maintained.

In addition, apart from the above proposal, two reinforcing fiber yarn groups aligned in a sheet shape are overlapped with each other so that the yarns of each sheet cross each other, and the two sheets are laid using auxiliary yarns. A so-called non-crimp woven fabric held together is known (for example, Japanese Patent Publication No. 57-52221, U.S. Pat. No. 4,906,506).

[0009] However, such a reinforcing woven fabric has very small surface irregularities due to the fact that the reinforcing fiber yarn does not have a bend, but is mainly a bidirectional woven fabric. The reinforcing fiber yarns are oriented. Therefore, the efficiency of reinforcement with respect to the used amount is not always high, and the reinforcing base material may be unnecessarily thick, which may deteriorate the handleability.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems in a unidirectional reinforcing fabric,
Another object of the present invention is to provide a unidirectional reinforced fabric suitable for reinforcing a cement-based structure and the like, in addition to a general structure, and a method for producing the same.

[0011]

In order to achieve the above object, the unidirectional reinforcing fabric of the present invention comprises a flat reinforcing fiber multifilament yarn which does not have a bend such that stress is concentrated and is parallel to each other in one direction. In addition, a weft direction auxiliary yarn group that intersects with the reinforcing fiber multifilament yarn is located on both sides of the sheet surface of the yarn group aligned in a sheet shape, and the weft direction auxiliary yarn group and the warp parallel to the reinforcing fiber multifilament yarn. The direction-assisting yarn group forms a woven structure and integrally holds the yarn group, and the reinforcing fiber multifilament yarn has a fineness of 7,200 to 20,000 denier and a bunching property.
Is in the range of 100-1,000mm in hook drop value
And a yarn width / yarn thickness ratio of 30 or more.

[0012] In the unidirectional reinforcing fabric of the present invention, the reinforcing fiber multifilament yarn has a yarn width / yarn thickness ratio of 30 or more and is kept in a very flat state. The flat reinforcing fiber multifilament yarns are aligned in one direction in parallel with each other, in a sheet shape, and in a state having no bend such that stress is concentrated. The direction auxiliary yarn group is arranged, and the weft direction auxiliary yarn group and the warp direction auxiliary yarn group parallel to the reinforcing fiber multifilament yarn are woven, and the reinforcing fiber multifilament yarn group is held integrally. Since the reinforcing fiber multifilament yarn group is sandwiched and integrated by two intersecting weft direction auxiliary yarn groups, almost no force acts to sandwich the width of the reinforcing fiber multifilament yarn. A wide yarn width and a flat state are stably maintained, and the surface of the fabric is flat and uniform with very few surface irregularities.

When a cement-based structure or the like is reinforced with a woven fabric substrate, if the bonding surface of the woven fabric substrate is uneven, a large amount of the adhesive is present in the adhesive structure and the concave portion of the woven fabric substrate. Also, there is a problem that a large amount of adhesive is used, and when a stress is applied, the stress is concentrated on a portion where a large amount of the adhesive is present, and cracks are generated from the portion. In particular, when repetitive stress acts on a highway, there is a problem that the cracks proceed and the adhesive surface is peeled off, and the surface of the woven fabric substrate needs to be uniform. Since the unidirectional reinforcing fabric of the present invention becomes a substrate having an extremely uniform surface as described above, such a requirement can be satisfied exactly.

Further, since the reinforcing fiber multifilament yarn does not have a bend such that stress is concentrated, almost all of the reinforcing fibers are oriented in a predetermined reinforcing direction when formed into FRP, so that the target is extremely efficiently targeted. Can exhibit strength characteristics. Moreover, the reinforcing fiber multifilament yarn has a yarn width /
Because the yarn thickness ratio is 30 or more and the flatness is large,
A thin and smooth woven fabric substrate can be obtained, and the resin impregnating property and the uniformity of the distribution of the reinforcing fibers can be maintained extremely well. Therefore, generation of voids and resin-rich portions can be suppressed, and more uniform and high-strength characteristics of the FRP molded product and the FRP structure can be realized.

A specific embodiment of the unidirectional reinforcing fabric according to the present invention will be described with reference to the drawings. FIG. 1 shows a unidirectional reinforcing fabric according to an embodiment of the present invention. In the drawing, reference numeral 1 denotes a flat reinforcing fiber multifilament yarn having no bending so that stress is concentrated. The reinforcing fiber multifilament yarns 1 are aligned in a direction parallel to each other and in a sheet form to form one yarn group. Then, two weft direction auxiliary yarn groups 2 and 3 intersecting the reinforcing fiber multifilament yarn 1 on both upper and lower surfaces of the sheet and one warp direction auxiliary yarn group 4 parallel to the reinforcing fiber multifilament yarn 1 are woven. And are held together.

FIG. 2 shows a cross section of a unidirectional reinforcing fabric according to another embodiment of the present invention, in which a plurality of (in this embodiment, two layers) multifilamentary reinforcing fiber yarns 1 are laminated. The laminated reinforcing fiber multifilament yarns 1 are aligned in one direction parallel to each other and in a sheet shape in the same manner as shown in FIG. 1 to form one yarn group. Then, two weft direction auxiliary yarn groups 2 and 3 intersecting the reinforcing fiber multifilament yarn 1 on both sides of the sheet and one warp direction auxiliary yarn group 4 parallel to the reinforcing fiber multifilament yarn 1 are woven and integrated. Is held in.

In the embodiment shown in FIGS. 1 and 2, the warp direction assisting yarns 4 are located on both sides of the sheet surface.
3, but may be interleaved every few lines. Further, the warp direction assisting yarns 4 are arranged at respective positions between the adjacent reinforcing fiber multifilament yarns, but may be arranged every several reinforcing fiber multifilament yarns.

It is preferable that the weft direction auxiliary yarns 2 and 3 have higher rigidity than the warp direction auxiliary yarn 4, so that the weft direction auxiliary yarns 2 and 3 do not need to sink, and the reinforcing fiber multifilament yarn is used. A large gap can be prevented from being generated between the two. Therefore, a high cover factor of the reinforced multifilament yarn 1 can be realized. It is preferable that the weft direction auxiliary yarns 2 and 3 extend substantially straight. Thus, similarly, it is possible to prevent a large gap from being generated between the reinforcing fiber multifilament yarns 1 and to realize a high cover factor of the reinforcing fiber multifilament yarn 1.

The cover factor of the fabric is preferably 90% or more, more preferably 95% or more.

Here, the cover factor (Cf) is
When a region having an area S1 is set in the woven fabric base material, the following formula is obtained from the area S1 and the area S2 occupied by a portion other than the fiber material existing in the region: / S1] × 100.

As described above, the surface of the woven fabric is smooth because one or more layers of the flat reinforcing fiber multifilament yarns are aligned in one direction in parallel with each other and in a sheet shape. . However, if there is a gap between the parallel yarns, the portion becomes a resin-rich portion, which is disadvantageous in terms of characteristics, and requires extra resin, which is not economically preferable. Therefore, the gap is preferably as small as possible, and as described above, the cover factor of the woven fabric is preferably 90% or more, and more preferably 95% or more.

In order to achieve such a high cover factor, the reinforcing fiber multifilament yarn is flat as described above, and at the same time, the convergence of the reinforcing fiber multifilament yarn is 100 to 1,000 in terms of hook drop value.
It is preferable that the multifilament yarn group is easy to spread and widen in the range of mm and has substantially no twist.

Here, the hook drop value is a factor related to the convergence of the reinforcing fiber multifilament yarn, and is a value of the free fall distance of the hook measured by the measuring method shown in FIG. First, the reinforcing fiber multifilament yarn 101
Was analyzed without twisting and untwisting the woven fabric, and a flat reinforcing fiber multifilament yarn 101 having a length of 120 cm was twisted at both ends of the yarn under an initial load of 50 mg / denier. Is fixed in the vertical direction so that the flat state is not collapsed. Next, at a position of 10 cm from the upper fixing portion of the fixed reinforcing fiber multifilament yarn, a metal wire diameter of 1 mm and a radius of 5 mm are connected to a hook 102 having a diameter of 3 cm at approximately the center of the width of the reinforcing fiber multifilament yarn. Weight 103 with cotton thread
Is attached, and the free fall distance of the hook 102 is measured. In the case of a thread, 10 bobbins are randomly extracted from the bobbins to be used, and 10 measurements are performed for each bobbin.
N = 7 which is the value obtained by deleting three large values from the 0 measurement values
The average value of 0 is defined as the hook drop value. In the case of a woven fabric, three 1.3-m-long woven fabrics are extracted in the length direction, and the warp or weft is loosened from each woven fabric so that fluff does not occur and twisting does not occur. 10 measurements of warp or weft for the woven fabric
N = 2 of the value obtained by deleting three large values from the zero measurement values
The average value of 1 is defined as the warp or weft hook drop value. In addition, the weight of the wire and the cotton yarn is made as small as possible, and the total weight of the wire, the cotton yarn and the weight is set to 30 g.

The larger the hook drop value, the easier the reinforcing fiber multifilament yarn is opened and widened. However, if the size is too large, the shape retention of the multifilament yarn is lost, and it becomes difficult to weave a woven fabric. By setting the convergence in the above range with the hook drop value, an optimum flat state of the woven yarn in the form of a woven fabric is obtained and the flat state is maintained.

For example, in the case of a reinforced woven fabric using carbon fiber yarns, in general, air is blown to the fiber bundle of the precursor in the manufacturing process of the carbon fiber in order to prevent a process trouble due to winding of the cut filament around a roller in the manufacturing process. The filaments are entangled with each other to give the carbon fiber yarn a sizing property. In addition, the sizing agent is attached to the carbon fiber yarns by the amount of the sizing agent and the adhesion between the carbon fiber filaments. The degree of convergence is determined by the degree of entanglement between filaments, the amount of sizing agent attached, and the degree of adhesion by the sizing agent. However, if the hook drop value is 100 mm or less, and the degree of convergence is too large, the convergence of carbon fiber When hand lay-up molding or prepreg processing is performed, the width of the warp and weft yarns of the woven fabric does not increase, and voids of the resin are intensively generated in the voids formed between the carbon fiber yarns. In addition, when processed into a prepreg, the impregnating property of the resin deteriorates, and a high-performance FRP cannot be obtained. On the other hand, if the hook drop value is 1,000 mm or more, the convergence of the carbon fiber yarn is deteriorated, fuzzing occurs during weaving, and not only the working environment is deteriorated, but also the strength of the FRP is reduced.

The hook drop value is determined by various factors such as the hardness of the sizing agent, the amount of adhesion, the number of twists, and the entangled state of the reinforcing fibers, and this value depends on the performance of the woven fabric and the impregnation of the resin. I found that it was closely related. In other words, the thing with a high hook trop value means that the orientation of the reinforcing fibers is uniform and the adhesion between the fibers by the sizing agent is small, so that the resin is easily impregnated by hand lay-up and the fiber orientation is uniform. Therefore, it can be said that it is a high-performance reinforcing fabric. In particular, in reinforcing a bridge pier on an elevated road, the resin is impregnated by hand lay-up on site, and therefore, it is essential that the resin impregnating property is high in view of work efficiency and the like. In addition, a woven fabric having a high hook drop value of a group of reinforcing fiber yarns has an advantage that the woven yarn width can be easily expanded by hand lay-up, and a high-performance fiber reinforced resin having a uniform fiber filling density can be obtained.

Further, it is necessary that the woven yarn composed of the above-mentioned reinforcing fiber multifilament yarn has substantially no twist. Here, "substantially no twist" refers to a state in which there is no twist of one or more turns per 1 m of yarn length. That is, it is a state in which there is no twist.

If the woven yarn is twisted, the yarn width becomes narrow and converges at the twisted portion to increase the thickness, and irregularities are generated on the surface of the woven fabric. For this reason, in the woven fabric, when an external force acts, stress concentrates on the twisted portion, and the FRP
When formed into a uniform shape, the strength characteristics become non-uniform.

A reinforcing woven fabric made of such an optimally flat woven yarn having substantially no twist can be used as a reinforcing fiber multifilament even if the fineness of the woven yarn is increased or the fiber density is increased. Since the yarn is maintained in a state where it is straightened in one direction while being kept in a flat state, high strength characteristics can be obtained when FRP or CFRP is used. Further, since the fineness of the woven yarn can be increased, the woven yarn and, eventually, the reinforcing woven fabric can be manufactured at lower cost.

Further, the fabric weight can be easily set high, and the cover factor can be set close to 100% in a state where the flat state of the yarn is secured. Therefore, in the FRP or the like, the fiber content can be set high, and the resin-rich portion between the woven yarns can be extremely small, so that a composite material having high strength and uniform strength characteristics can be obtained.

Furthermore, since each reinforcing fiber multifilament yarn is maintained in a flat state in the form of a woven fabric, the impregnating property of the resin is extremely good. Therefore, a composite material having more uniform characteristics can be obtained, and a desired strength characteristic can be easily obtained.

The number of layers of the reinforcing fiber multifilament yarns is determined by the required fabric weight. If a fabric having a high fabric weight is required, a low fabric weight fabric can be used while being superposed. However, since the work on site becomes complicated or the number of laminations is incorrect, a woven fabric in which a plurality of reinforcing fiber multifilament yarns are laminated, that is, FIG.
It is preferable to make the fabric as shown in FIG.

In such a unidirectional reinforcing fabric according to the present invention, the reinforcing fiber multifilament yarn preferably has a yarn thickness of 0.07 to 0.2 mm. If the yarn thickness is less than the above range, it is difficult to maintain the shape of the flat yarn because it is too thin, and if it exceeds the above range, the resin impregnation property and the like may be reduced. On the other hand, if the yarn width / yarn thickness ratio is less than 30, it is difficult to achieve the hook drop value as described above. Although the upper limit of the yarn width / yarn thickness ratio is not particularly limited, the upper limit is about 150 in consideration of the hook drop value and the easiness of the actual weaving process. In addition, the yarn width is preferably in the range of about 4 to 16 mm for easy weaving.

The unidirectional reinforcing fabric according to the present invention has a fabric thickness of 0.1 to 0.3 mm and a fabric weight of 100 to 320 g / m2 in the case of the fabric shown in FIG.
It is preferably ² . In uni-directional woven fabric according to the present invention, fiber <br/> of the yarns reinforcing fibers multifilament is in the range of 7,200 to 20,000 deniers
You. In particular, the lower limit of this range, 7,200 denier,
This is a value in the embodiment described later.

When the reinforcing fiber multifilament yarn is a carbon fiber yarn, the basis weight of the woven fabric viewed from the carbon fiber yarn and the fineness of the carbon fiber yarn satisfy the following relationship:
It is preferable that the cover factor is 95% or more. W = k · D ^1/2 where, W: fabric basis weight (g / m ²⁾ k: proportional constant (0.9-2.0) D: fineness of the carbon fiber yarns (deniers)

In the case where a woven fabric of a multi-filament reinforced fiber multi-filament yarn as shown in FIG. 2 is used,
The fabric thickness is 0.2 to 0.6 mm and the fabric weight is 200 to 5
It is preferably 00 g / m ² . Since it is a reinforced fiber multifilament yarn having a large yarn width / yarn thickness ratio, even when woven in such a state that a plurality of layers are laminated, the woven yarn can still maintain a flat state, and has a flat surface and a good resin. The impregnating property and the like can be maintained. Lamination can increase the fiber density of the woven fabric.

Here, the fiber density of the fabric means a value defined by the following equation. Fiber density of fabric (g / m ³ ) = [weight of fabric (g / m ³ )
m ² )] / [fabric thickness (mm)] The fabric weight (g / m ² ) and the fabric thickness (mm)
Is a value measured according to JIS R7602.

[0038]

When the reinforcing fiber multifilament yarn is made of carbon fiber yarn, the basis weight of the carbon fiber yarn and the fineness of the carbon fiber yarn satisfy the following formula, and the cover factor is 95% or more. It is preferred that W = k · D ^1/2 where, W: fabric basis weight (g / m ²⁾ k: proportional constant (from 2.0 to 4.2) D: fineness of the carbon fiber yarns (deniers)

When the reinforcing fiber yarn is a carbon fiber yarn, it is necessary that the carbon fiber flat yarn used has a large tensile elongation at break and a high tensile elongation at break, and the tensile elongation at break is 1.5%. As described above, the tensile breaking strength is 200 kg · f / mm ²
As described above, the tensile modulus is desirably 20,000 kg · f / mm ² or more.

Further, as a method for producing the flat yarn itself as described above, for example, in the production process of the reinforcing fiber yarn,
A fiber bundle composed of a plurality of reinforcing fibers may be spread to a predetermined width by a roll or the like, and may be held in a flat shape or may be held in a sizing agent or the like so as not to return to the original shape. In particular, to maintain the flat shape well,
It is preferable that a small amount of about 0.5 to 2.0% by weight of a sizing agent is adhered to the flat yarn.

As the auxiliary yarn in the unidirectional reinforcing fabric of the present invention, it is preferable to use a woven yarn composed of fine fibers having a fineness of 2,000 denier or less, more preferably 50 to 600 denier. If the fineness of the auxiliary yarn is large, the crimp becomes large, and if the fineness is small, it is easy to cut in weaving and handling. This auxiliary yarn is used for the purpose of holding parallel flat reinforcing fiber multifilament yarns together, and uses inorganic fibers such as carbon fiber and glass fiber, and organic fibers such as polyaramid fiber, vinylon fiber and polyester fiber. Yes, there is no particular limitation on the type.

It is preferable that the auxiliary yarn in the warp direction and / or the weft direction has a tensile elongation at break larger than that of the multifilament yarn of the reinforcing fiber. Thereby, the role of the auxiliary yarn for holding the reinforcing fiber multifilament yarn group together more reliably is achieved.

When the reinforcing fiber multifilament yarn is a carbon fiber yarn, the auxiliary yarn for holding the carbon fiber yarn integrally is a glass fiber yarn or a glass fiber yarn having a high elongation at break with high strength and high elasticity. Aramid fiber yarn is preferred. Further, the fineness of the auxiliary yarn is preferably about 1/5 to 1/20 of the fineness of the flat carbon fiber yarn. By doing so, the integrated auxiliary yarn is bent as necessary, and the carbon fiber flat yarn can be maintained straight.

In the unidirectional reinforcing fabric of the present invention, the reinforcing fiber multifilament yarn and the auxiliary yarn are formed by including a low-melting polymer extending in a linear or dot shape as an adhesive in the reinforcing fiber multifilament yarn or the auxiliary yarn. Alternatively, the auxiliary yarns can be sealed by bonding. As a result, the predetermined weaving structure is more reliably maintained, and the reinforcing fiber multifilament yarn group aligned in one direction is surely maintained in a predetermined form.

As the low melting point polymer used, nylon, copolymerized nylon, polyester, vinylidene chloride,
Examples include vinyl chloride and polyurethane. Among them, copolymerized nylon, for example, copolymerized nylon of nylon 6, 66 and 610, and copolymerized nylon of nylon 6, 12, 66 and 610 are preferable because of good adhesion to the thermosetting resin.

For example, as shown in FIG. 4, an adhesive 5 of a low-melting polymer is linearly or dot-like (dotted in the illustrated example) at the center of the reinforcing fiber multifilament yarn 1 in the longitudinal direction of the reinforcing fiber multifilament yarn 1. ), And the reinforcing yarn multifilament yarn 1 and the intersecting weft direction auxiliary yarns 2 and / or 3 are bonded. The preferred amount of adhesive 5 is 0.1-5% by weight of the fabric weight. However, since the adhesive 5 is different from the matrix resin, it is preferable that the adhesive 5 is as small as possible if it can be bonded.

As described above, since the adhesive 5 is linearly arranged at the center of the reinforcing fiber multifilament yarn 1, the reinforcing fiber multifilament yarn 1 and the auxiliary yarns 2 and / or 3 are securely bonded. Thus, the fabric can be easily handled without disturbing the fiber orientation in actual use. When several woven fabrics of the present invention are used by laminating them, the fabrics can be adhered to each other by applying heat with an iron or the like while laminating, and there is an advantage that work is easy. At this time, if the adhesive is arranged only on one side of the fabric, the fabric can be bonded without the adhesive being attached to the iron.

The adhesive made of the low melting point polymer may be arranged as shown in FIG. In FIG. 5, the auxiliary yarns in the warp direction and / or the weft direction (the warp direction auxiliary yarns 4 in the illustrated example) include an adhesive 5, and the adhesive 5
The warp direction auxiliary yarn 4 and the weft direction auxiliary yarns 2 and 3 are adhered to each other at their intersections. The adhesive 5 extends linearly or in a point (in this embodiment, linear). This adhesive 5 may extend spirally with respect to the auxiliary yarn.

Further, although not shown, the weft direction auxiliary yarn located on at least one side of the reinforcing fiber multifilament yarn sheet contains a low melting point polymer, and the polymer is crossed at the intersection with the warp direction auxiliary yarn. It is good also as an aspect which has adhere | attached to the warp direction auxiliary | assistant yarn, and also adheres to a reinforced fiber multifilament yarn.

By arranging the low-melting polymer in both the warp direction and the weft direction auxiliary yarn, the reinforcing fiber multifilament yarn and the auxiliary yarn, and the intersections between the auxiliary yarns can be more securely adhered to each other, and a stronger sealing is achieved. It can be carried out.

Using the unidirectional reinforcing fabric of the present invention as described above , a prepreg, an FRP according to the present invention, and a structure reinforced using the FRP can be obtained.

[0053] If you want to create a Oite prepreg to the present invention
It is assumed that the above-described unidirectional reinforcing fabric of the present invention is impregnated with 30 to 70% by weight of a matrix resin . A more preferred resin amount is 35 to 45% by weight.

Examples of the matrix resin used include thermosetting resins such as epoxy resin, unsaturated polyester resin, polyimide resin, and phenol resin. These thermosetting resins are in the B stage when impregnated in the fabric. Also, as the matrix resin, nylon resin,
Polyester resin, polybutylene terephthalate resin,
Thermoplastic resins such as polyetheretherketone (PEEK) resin and bismaleimide resin can also be used.

In order to prevent the occurrence of microcracks in a fiber-reinforced composite material using such a prepreg, the tensile elongation at break in the cured or solidified state of the matrix resin is determined by the elongation at break of the reinforcing fiber multifilament yarn of the reinforcing fabric. It is effective to make it larger than the degree. For example, the matrix resin is preferably a thermosetting resin having a tensile elongation at break of 3.5 to 10% or a thermoplastic resin having a tensile elongation at break of 8 to 200% in a solidified state.

The FRP according to the present invention contains the above-described unidirectional reinforcing fabric of the present invention and contains 30 to 70% by weight.
Comprising a matrix resin. As the matrix resin, the same thermosetting resin or thermoplastic resin as described above can be used. In addition, the tensile elongation at break of the matrix resin is preferably larger than the tensile elongation at break of the reinforcing fiber multifilament yarn of the reinforcing fabric, and the tensile elongation at break is 3.
5 to 10% thermosetting resin or tensile elongation at break of 8 to 2
It is preferred to use 00% thermoplastic resin.

An FRP molded product using the above prepreg can be molded by a known method. A predetermined number of prepregs are laminated in a predetermined direction, and when the matrix resin is a thermosetting resin, 4 to 10
By curing the resin under pressure of kg / cm ² ,
In the case of a thermoplastic resin, it can be molded by heating above the melting point of the resin under a pressure of 7 to 30 kg / cm ² to melt and cool the resin.

The structure reinforced by using the FRP according to the present invention can be obtained, for example, by winding a predetermined number of the above-described prepregs around the object to be reinforced and, for example, heat-curing the prepreg. Further, if possible, a predetermined number of wraps may be wound around the object to be reinforced in the form of a woven fabric or a preform, and the resin may be impregnated with pressure and cured.

The unidirectional reinforcing woven fabric according to the present invention has very little unevenness and is flat, and is excellent in handleability and resin impregnating property, so that it can have a large adhesion area with the object to be reinforced. It is easy to apply, and the molded FRP can be uniform and have high physical properties without resin-rich portions and voids. Therefore, it is optimally used for reinforcing cement-based structures.

The unidirectional reinforcing fabric of the present invention is manufactured, for example, as follows. That is, in the method for producing a unidirectional reinforcing fabric according to the present invention, the fineness is 7,200 to 2,000.
0 denier, convergence is 100 ~ 1, hook drop value
The flat reinforcing fiber multifilament yarns having substantially no twist in the range of 000 mm are aligned in one direction in parallel with each other in a sheet form, and the reinforcing fiber multifilament yarns are laid in parallel between the reinforcing fiber multifilament yarns. A method comprising supplying a direction assisting yarn, drawing and aligning it in a sheet form, opening and closing a sheet of a reinforcing fiber multifilament yarn and a sheet of a warp direction assisting yarn, and supplying a weft direction assisting yarn between the two sheets. Consists of

More specifically, referring to the drawings, as shown in FIGS. 6 and 7, the flat reinforcing fiber multifilament yarn 11 is formed by the mails 12a, 12a.
, And passes the warp direction auxiliary thread 13 through the mail 12a, 1
The mails 12b, 12b,... Between 2a,. 6 and 7, between the sheet composed of the yarn group of the reinforcing fiber multifilament yarn 11 to be opened and closed and the warp direction auxiliary yarn group 13.
As shown in (1), the weft direction auxiliary yarns 15 are sequentially supplied to weave the unidirectional reinforcing fabric according to the present invention. The weft direction auxiliary yarns 15 are alternately arranged on both sides of the reinforcing fiber multifilament yarn sheet, and the weft direction auxiliary yarns 15 and the warp direction auxiliary yarns 13 are woven to form a reinforcing fiber multifilament yarn group. Are held together. As the loom, a known rapier loom or the like can be used.

[0062]

【Example】

Example 1 Tensile breaking strength was 500 kgf / mm ² and tensile modulus was 2
Carbon fiber with 3,500 kgf / mm ² and elongation at break of 2.1% (trade card T700SC-12K manufactured by Toray Industries, Inc.)
(Fineness: 7,200 denier), the carbon fiber is spread flat with a yarn width of 6.5 mm, and the shape is maintained with a sizing agent. In the subsequent steps, the flat yarn is kept in the same heald frame. Two healds are stacked on each heddle, and each heald of another heald frame is made of glass fiber yarn (Nittobo Co., Ltd.)
ECE225-1 / 2) is supplied so that the carbon fiber yarn and the glass fiber yarn are alternately arranged one by one.

Then, the heald frame through which the carbon fiber yarn and the glass fiber yarn are passed is alternately moved up and down as shown in FIGS. 6 and 7, and a glass fiber yarn (Nitto Weaving was performed by inserting ECG75-1 / 2 (manufactured by Spinning Co., Ltd.). Further, the hook drop value of the carbon fiber yarn constituting the woven fabric was 220 mm, and the cover factor of the woven fabric was 95%. The density of the warp yarns composed of carbon fiber yarns is 1.25 yarns / c in a unit of a laminated state.
m, the weft density was 0.5 yarn / cm, and the basis weight of the carbon fiber was 200 g / m ² .

The surface of the obtained woven fabric was very flat and uniform, and the carbon fiber yarns were straight and maintained in a flat state. The woven fabric was impregnated with an unsaturated polyester resin by hand lay-up, four sheets were laminated in the same direction, and cured at room temperature to prepare a cured plate. When a hardened plate was prepared, it could be easily impregnated with the resin, and the obtained hardened plate had no voids and a uniform surface. The tensile strength of the cured plate was measured according to the CFRP tensile test method of JIS-K7073. The results are shown in Table 1 together with the carbon fiber volume content and tensile modulus.

Comparative Example 1 The same yarn as the carbon fiber yarn used in Example 1 was used as a warp yarn.
Weft to glass fiber yarn (ECE22 manufactured by Nittobo Co., Ltd.)
5-1 / 2) and woven by a conventional weaving method with a plain weave structure. The weaving density of the carbon fiber yarn of the warp yarn is 2.5
Yarn / cm, weaving density of weft glass fiber yarn is 0.5 yarn / cm
cm, and the basis weight of the carbon fiber is 200 g / m as in Example 1.
^{And 2} .

In the obtained woven fabric, the flat carbon fiber yarns are folded in the width direction, bundled and interlaced with the weft yarns, so that the woven fabric surface is uneven. Also, since the thickness of the weft yarn is too thin compared to the warp yarn thickness, high tension of the warp yarn is applied to the weft yarn that has already been driven in at the time of opening the warp yarn. There was a problem that the warp yarn arrangement was disturbed.

From this fabric, a cured plate was prepared in the same manner as in Example 1. In the resin impregnation operation, the same amount of resin as in Example 1 was prepared due to the unevenness of the woven fabric. In the obtained cured plate, the unevenness of the fabric appeared as it was, and the surface was uneven. The tensile strength of the cured plate was measured in the same manner as in Example 1. The results are shown in Table 1 together with the carbon fiber volume content and tensile modulus.

[0068]

[Table 1]

[0069]

As described above, according to the unidirectional reinforced fabric and the method for producing the same of the present invention, the fineness is 7,200 to 2,000 , which does not have a bend such that stress is concentrated.
0 denier, convergence is 100 ~ 1, hook drop value
A flat reinforcing fiber multifilament yarn having a yarn width / yarn thickness ratio of 30 or more in a range of 000 mm is drawn in parallel in one direction and in a sheet form, and is reinforced with a weft direction auxiliary yarn group arranged on both sides of the sheet surface. Since it is woven by the fiber multifilament yarn and the warp direction auxiliary yarn group in parallel, it is a reinforcing fiber multifilament yarn having a large fineness.
Even though the fibers are oriented straight in a predetermined direction, and the reinforcing fiber multifilament yarn is uniformly dispersed at a high fiber density without being bundled by the tightening of the weft direction auxiliary yarn, so the high tensile strength and elasticity of the reinforcing fiber have The rate is fully demonstrated.

Also, since the hook drop value of the reinforcing fiber multifilament yarn is increased , each single fiber can be oriented more uniformly, and the adhesion of the single fiber by the sizing agent can be reduced. It can be easily impregnated, and can be an optimal woven fabric as a reinforcing substrate.

Further, since the surface of the woven fabric is smooth, for example, in the case where the woven fabric is bonded to a cement structure for reinforcement, a high bonding effect can be obtained since the bonding agent is uniformly present on the bonding surface.
In particular, a high effect can be obtained for those on which repeated stress acts, such as a highway.

Further, if the low melting point polymer is provided and sealed, a desired woven fabric form can be more stably maintained, and one having a high form retention property that can sufficiently withstand outdoor work. A directional reinforcing fabric is obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view of a unidirectional reinforcing fabric according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a unidirectional reinforcing fabric according to another embodiment of the present invention.

FIG. 3 is a perspective view of an apparatus for measuring a hook drop value.

FIG. 4 is a perspective view of a unidirectional reinforcing fabric according to still another embodiment of the present invention.

FIG. 5 is a perspective view of a unidirectional reinforcing fabric according to still another embodiment of the present invention.

FIG. 6 is a partial perspective view of a loom illustrating a method for producing a unidirectional reinforcing fabric of the present invention.

FIG. 7 is a perspective view showing another operation state of the loom of FIG. 6;

[Explanation of symbols]

 1,11,101 Reinforcing fiber multifilament yarn 2,3,15 Weft direction auxiliary yarn 4,11 Warp direction auxiliary yarn 5 Low melting polymer

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-58-191244 (JP, A) JP-A-1-40632 (JP, A) JP-A-62-276053 (JP, A) JP-A-4- 281037 (JP, A) JP-A-61-138743 (JP, A) JP-A-10-331047 (JP, A) JP-A-11-1840 (JP, A) JP-A-7-243147 (JP, A) Patent 2955145 (JP, B2) Patent 2836457 (JP, B2) Patent 3089894 (JP, B2) Patent 3094835 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) D03D 1/00-27 / 18 B29B 11/16 C08J 5/24

Claims (24)

(57) [Claims] 1. A reinforcing fiber multifilament yarn on both sides of a sheet surface of a group of yarns in which flat reinforcing fiber multifilament yarns having no bending so as to concentrate stress are aligned in one direction in parallel with each other in a sheet shape. And a weft direction auxiliary yarn group that intersects with them, the weft direction auxiliary yarn group and the warp direction auxiliary yarn group parallel to the reinforcing fiber multifilament yarn form a woven structure and integrally hold the yarn group, and ,
The reinforcing fiber multifilament yarn has a fineness of 7,20.
0-20,000 denier, focusing ability is hook drop value
And a yarn width / yarn thickness ratio of 30 or more. 2. The multifilament yarn of claim 1, wherein the reinforcing fiber multifilament comprises a low-melting polymer extending linearly or dotwise in a length direction thereof, and the low-melting polymer is bonded to a weft-direction auxiliary yarn. 1 unidirectional reinforcing fabric. 3. The warp-direction and / or weft-direction auxiliary yarns comprise a low-melting polymer, wherein the warp-direction auxiliary yarns and the weft-direction auxiliary yarns are bonded to each other at their intersections. 1 or 2 unidirectional reinforced fabrics. 4. The weft direction assisting yarn located on at least one side of the sheet surface includes a low melting point polymer, and the polymer adheres to the warp direction assisting yarn at an intersection with the warp direction assisting yarn. The unidirectional reinforced fabric according to claim 1 or 2, wherein the woven fabric is bonded to the reinforcing fiber multifilament yarn. 5. The unidirectional reinforcing fabric according to claim 2, wherein the low melting point polymer is selected from nylon, copolymerized nylon, polyester, vinylidene chloride, vinyl chloride, and polyurethane. . 6. The unidirectional reinforcing fabric according to claim 1, wherein the warp direction assist yarns are alternately crossed with the weft direction assist yarns located on both sides of the sheet surface. 7. The unidirectional reinforcing fabric according to claim 1, wherein the weft direction assisting yarn has higher rigidity than the warp direction assisting yarn. 8. The unidirectional reinforced fabric according to claim 1, wherein the weft direction assisting yarn extends substantially straight. 9. The method according to claim 9, wherein the cover factor is 90% or more.
The unidirectional reinforcing fabric according to any one of claims 1 to 8. 10. The unidirectional reinforcing fabric according to claim 1, wherein the reinforcing fiber multifilament yarn is a carbon fiber yarn. 11. The multifilament yarn of the reinforcing fiber is a multifilament yarn having substantially no twist.
The unidirectional reinforcing fabric according to any one of claims 1 to 10. 12. The unidirectional reinforcing fabric according to claim 1, wherein a thickness of the reinforcing fiber multifilament yarn is 0.07 to 0.2 mm. 13. The unidirectional reinforcing fabric according to claim 1, wherein the fabric thickness is 0.1 to 0.3 mm and the fabric weight is 100 to 320 g / m ² . 14. The multi-filament yarn of a reinforcing fiber is made of a carbon fiber yarn, and has a fabric weight as viewed from the carbon fiber yarn.
The fineness of the carbon fiber yarn satisfies the following relationship, and
The unidirectional reinforcing fabric according to any one of claims 1 to 13, wherein the cover factor is 95% or more . W = k · D ^1/2 where, W: fabric basis weight (g / m ²⁾ k: proportional constant (0.9-2.0) D: fineness of the carbon fiber yarns (deniers) 15. The multi-filament reinforced fiber yarn
13. The method according to claim 1, wherein a plurality of the layers are stacked.
The reinforced fabric according to the above. 16. A woven fabric having a woven fabric thickness of 0.2 to 0.6 mm.
Basis weight is 200-500 g / m ^2, reinforcing fabric of claim 15. 17. The method according to claim 17, wherein the reinforcing fiber multifilament yarn is
It is made of carbon fiber yarn, and has a fabric weight per unit area as seen with the carbon fiber yarn.
The fineness of the carbon fiber yarn satisfies the following relationship, and
The cover factor is not less than 95%,
Is 16 reinforced fabrics. W = k · D ^1/2 where, W: fabric basis weight (g / m ²⁾ k: proportional constant (from 2.0 to 4.2) D: fineness of the carbon fiber yarns (deniers) 18. The vertical direction and / or the horizontal direction.
The tensile elongation at break of the auxiliary yarn of the above is the reinforcing fiber multifilament.
2. The tensile elongation at break is greater than the tensile elongation at break of the thread.
8. The unidirectional reinforcing fabric according to any one of 7 above . 19. The auxiliary yarn is a carbon fiber yarn or a glass fiber.
Yarn, polyaramid fiber yarn, vinylon fiber yarn, polyester
19. A fiber yarn selected from the group consisting of:
The unidirectional reinforcing fabric according to any one of the above . 20. A method according to claim 1, wherein
And comprises 30 to 70% by weight of a unidirectional reinforcing fabric.
Fiber reinforced plastic containing matrix resin. 21. The method according to claim 20, wherein the matrix resin is a thermosetting resin.
21. The fiber reinforced plus according to claim 20, which is a thermoplastic resin.
Chick. 22. The tensile elongation at break of the matrix resin is
Tensile elongation at break of reinforced multifilament yarn of reinforced fabric
22. The fiber reinforced plastic according to claim 20, wherein
Stick. 23. The method according to claim 20, wherein
Structure reinforced using the fiber-reinforced plastic described above. 24. A fineness of 7,200 to 20,000 deni.
And convergence are 100 to 1,000 hook drop values
mm, a substantially non-twisted flat reinforcing fiber multifilament yarn is aligned in one direction in parallel with each other and in a sheet form, and the reinforcing fiber multifilament yarn is set in parallel between the reinforcing fiber multifilament yarns. Feeding the direction assisting yarn, drawing and aligning it in a sheet form, opening and closing the sheet of the reinforcing fiber multifilament yarn and the sheet of the warp direction assisting yarn, and supplying the weft direction assisting yarn between the two sheets, A method for producing a unidirectional reinforced fabric.