JPS62158727A - Prepreg - Google Patents

Abstract

PURPOSE:To obtain a prepreg of an excellent reinforcing effect, a light weight and a low manufacturing cost, by adhering a specified woven fabric to one surface of a unidirectional prepreg. CONSTITUTION:Strands 1 of reinforcing fibers (e.g., carbon fiber) fed in parallel with each other in the form of a sheet are sandwiched between a 0.05-0.2mm-thick release paper 2 and a resin-coated release paper 3; heated to 50-150 deg.C on a hot plate 4 to increase the flow of the resin; fed between impregnation rolls at least either of which is heated; given a linear pressure of 3-8kg/cm to widen the strands and to impregnate them with the resin; and fed to a take-up roll 6, where the release paper 2 is peeled off to obtain a unidirectional prepreg 7 supported on the release paper 3. A woven fabric 8 in which the wefts consist of reinforcing fibers and the warps consists of low-melting polymer yarns (e.g., nylon yarn) is adhered to the prepreg 7 so that the direction of the warps may coincide with the direction of drawing of the reinforcing fiber of the prepreg and the direction of the wefts may coincide with the direction of width which is transverse to the direction of drawing, and the assemblage is fed between adhesion rolls 9 at least either of which is heated to 60-140 deg.C; given a linear pressure of 3-8kg/cm to effect adhesion; and wound around a core 11 through a take-up roll 10.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a prepreg used as a molding material for fiber reinforced resin (FRP).

Conventional gijutsu prepreg has traditionally been made by applying an ultra-thin reinforcing fiber fabric called scrim cloth to one side of the unidirectional prepreg, which is made by impregnating resin with reinforcing fibers drawn parallel to each other in a sheet shape in one direction. There is generally known a scrim cloth laminated prepreg in which the warp threads are attached in the direction in which the reinforcing fibers are aligned, and the weft threads are bonded in the width direction perpendicular to the direction in which the reinforcing fibers are aligned. . The above-mentioned scrim cloth prevents the arrangement of the reinforcing fibers from being disordered, and also provides a slight reinforcing effect in the width direction perpendicular to the direction in which the reinforcing fibers are arranged due to the weft. For example, when forming an FRP pipe using such a scrim cloth laminated prepreg, the prepreg is wound around a mandrel so that the reinforcing fibers are aligned in the longitudinal direction of the mandrel, and then a wrapping tape is applied. This is done by wrapping and heating the wrapping tape to harden the resin while applying pressure due to the thermal contraction force of the wrapping tape. At this time, as a result of slicing so that the reinforcing fibers are drawn in the longitudinal direction of the mandrel, the weft of the scrim cloth is oriented in the circumferential direction of the mandrel, and the FR
Compressive strength is given to the P pipe.

As mentioned above, the weft of scrim cloth has an important role of providing a reinforcing effect in the direction perpendicular to the direction in which the reinforcing fibers are drawn, but as mentioned above, scrim cloth is extremely thin, and therefore the amount of reinforcing fibers is Since there is little, the reinforcing effect is sometimes insufficient.

On the other hand, the warp threads of scrim cloth extend in the same direction as the reinforcing fibers of the unidirectional prepreg, as shown in (e) above, but the reinforcing effect in that direction is sufficient due to the reinforcing W4 fibers of the unidirectional prepreg. There is no need to expect a reinforcing effect from the warp threads. In other words, when it comes to the reinforcing effect alone, the weft threads are very important, but the warp threads not only play no role, but also hinder weight reduction, considering that the main purpose of FRP is weight reduction. It's even a factor. .

Due to such problems, for example, Japanese Patent Application Laid-Open No. 56-56850
The publication is made by arranging and pasting glass fibers or their prepregs (yarn prepregs) only in the width direction orthogonal to the alignment direction of the carbon taA, m on one surface of a unidirectional prepreg made of carbon fibers. We are proposing prepreg. In other words, this prepreg can be said to be obtained by removing only the warp of the scrim cloth from the above-mentioned scrim cloth laminated prepreg. However, this prepreg is very cumbersome to manufacture because it is necessary to align the glass fibers or their prepregs in one direction and at the desired spacing using a comb-shaped guide or the like prior to pasting. be.

On the other hand, JP-A-56-'1626/12@publication and JP-A-58-
Japanese Patent No. 212936 describes a prepreg formed by adhering two unidirectional prepregs such that the reinforcing fibers of the two unidirectional prepregs are perpendicular to each other, for example. In this laminated prepreg, one of the unidirectional prepregs is thinner than the other, and the reinforcing fibers of the thinner unidirectional prepreg are the wefts of the scrim cloth in the scrim cloth laminated prepreg described above. It plays the role of However, in this bonded prepreg, after preparing two unidirectional prepregs separately, the two unidirectional prepregs must be attached so that their reinforcing fibers are perpendicular to each other, for example. However, there are still problems in that it is not only difficult to manufacture, but also increases manufacturing cost.

This invention solves the above-mentioned drawbacks of conventional prepregs, and has other reinforcing fibers extending in the width direction of the unidirectional prepreg, making it possible to perform moderate, so-called widthwise reinforcement. Moreover, it is possible to provide a prepreg with low manufacturing cost.

4. To solve the problem -1 To achieve the above object, the present invention includes a unidirectional prepreg made by impregnating reinforcing fibers parallel to each other in one direction and in a sheet shape, on one side of the unidirectional prepreg. Weft reinforced IIi
The present invention is characterized by a prepreg made by pasting a woven fabric made of filaments, the warp of which is a low-melting polymer yarn, so that the warp is in the direction in which the reinforcing fibers are aligned.

Next, the prepreg of the present invention will be roughly explained in detail along with its manufacturing method.

In this invention, first, a unidirectional prepreg is prepared by soaking reinforcing fibers, which are aligned parallel to each other in one direction into a sheet shape, with a resin. This unidirectional prepreg itself is not particularly different from conventional prepregs, and can be manufactured by a well-known method.

For example, as shown in the drawing, two strands of reinforcing fibers 1 drawn out parallel to each other in a sheet shape are
Sandwich between sheets of release paper 2.3. At this time, resin is applied and supported on at least the surface of the release paper 3 located on the lower side to form a so-called resin-supported sheet. Next, the above-mentioned polymer is heated to 50 to 150° C., preferably 70 to 150° C., on a hot plate 4 to increase the fluidity of the resin, and then, if necessary, at least one of the immersion rolls 5 is heated. The strand 1 is expanded by applying a linear pressure of 3 to 8 KQ per 10 m, and the resin is transferred and impregnated, and the upper part of the paper 2 is roughly peeled off through a take-up roll 6. Then, the unidirectional prepreg 7 supported on the lower pattern 3 is obtained. The S-impregnated rolls may be provided in multiple stages as required, or the pressure rolls may be arranged in multiple stages on the hot plate without providing the impregnated rolls.

In the above, the reinforcing fibers are high-strength, high-elasticity fibers such as carbon fibers, glass fibers, aramid fibers, boron fibers, silicon carbide fibers, and alumina fibers. In addition, the release paper may be coated with a sealant and have a thickness of 0.05 to
Q: It's like applying a silicone-based or non-silicone-based release agent to the surface of a paper such as kraft paper, roll paper, glassine paper, etc. of about 2 mm. The resin that is coated and supported on the surface is, for example, a thermosetting resin such as epoxy resin, unsaturated polyester resin, phenol resin, or polyimide resin. For resin application and loading,
The resin-containing oil of the unidirectional prepreg that is finally obtained is
The weight should be 20-70,000%, preferably 30-50%.

Next, on the surface of the unidirectional prepreg obtained as described above from which the upper release paper has been peeled off, a fabric whose wefts are made of reinforcing fiber yarns and whose warps are made of low-melting polymer yarns is placed. The prepreg of the present invention is obtained by pasting the directional prepreg in such a way that the reinforcing fibers of the directional prepreg are aligned in the same direction, so that the wefts are in the width direction that intersects with the above-mentioned alignment direction. For example, as shown in the drawing, a fabric 8 whose wefts are made of reinforcing fiber yarns and whose warps are made of low-melting polymer yarns is placed on the peeled surface of the upper release paper 2, and the warp is made of unidirectional prepreg 7. The reinforcing fibers are aligned in the same direction, and the wefts are stacked in the width direction that intersects with the above-mentioned alignment direction.
The unidirectional prepreg 7 is passed through an adhesive roll 9 which has been heated to a temperature of 100°C, and is then applied with pressure to adhere to the peeling surface using the viscosity of the resin of the unidirectional prepreg 7. It may be done by winding it around the winding core 11. Lower release paper 3
is peeled off during molding. Note that the woven fabric may also be impregnated with the same resin as that impregnated into the unidirectional prepreg. In this case, the unidirectional prepreg resin (
6) should be slightly reduced. Further, the linear pressure applied by the adhering roll may be about 3 to 8 Kq per cm.

In the above fabric, the weft yarns are made of the above-mentioned reinforcing fibers, and the warp yarns are made of low melting point polymer yarns. However,
The weft yarns give the unidirectional prepreg a reinforcing effect in the width direction that intersects with the direction in which the reinforcing fibers are drawn.

On the other hand, the warp threads simply maintain the arrangement of the weft threads until they are used for FRP molding, and they melt at the temperature during molding and no longer maintain their thread form.

The low melting point polymer threads constituting the warp threads are, for example, monofilaments, multifilaments, and slit yarns of nylon, copolymerized nylon, polyester, vinylidene chloride, vinyl chloride, and the like. Among them,
Unidirectional prepreg resin, which forms the so-called matrix of FRP, has good adhesion with prepreg resin and can yield high strength and high elasticity FRP. For example, nylon 6 and 12 copolymers, nylon 6 and 66 copolymers, nylon 6.
66 and 610 copolymer, nylon 6.12.66
and 610 copolymers are preferred.

The amount of weft of the woven fabric may be determined depending on the use and the like.

For example, in the case of prepreg used for forming FRP pipes,
Generally speaking, FRP pipes are required to have fewer reinforcing fibers in the circumferential direction than in the longitudinal direction, so the amount of weft yarns should be reduced by weight to 5% between the reinforcing fibers of the unidirectional prepreg.
0% or less, the reinforcing fibers of the unidirectional prepreg are oriented in the longitudinal direction of the tube, and therefore the weft yarns of the fabric are oriented in the circumferential direction of the tube. On the other hand, the warp threads merely maintain the arrangement of the weft threads, as mentioned above, and do not act as reinforcing fibers (), and even if they melt during molding, they are essentially Basically, F
It forms the so-called matrix of RP. Therefore, although the warp thickness varies depending on the weft thickness, arrangement density, weaving structure, etc., the warp thickness should be set to less than one-half, preferably one-quarter or less, of the weft ends. It is also preferable that the thickness be as thin as possible so as not to bend the weft too much. This is because if the weft yarns, which have a reinforcing effect, are bent, when FRP is used, stress will be concentrated at the bent part, which will not only reduce the reinforcing effect, but also reduce the effect of developing elastic modulus. It is from.

The texture of the fabric is not particularly limited. However, a flat weave is most preferred because it is relatively easy to weave, has low manufacturing costs, and can be made thin. The structure may be a so-called orthogonal structure in which the weft and warp threads are orthogonal to each other, or may be a so-called bias structure in which the weft threads extend diagonally with respect to the warp threads. When a woven fabric with an orthogonal structure is used, the weft yarns can be arranged in the width direction perpendicular to the direction in which the reinforcing fibers of the unidirectional prepreg are arranged, and when a bias woven fabric is used, With respect to the above pulling direction,
For example, it can be arranged in any direction such as 45° or 60'.

Effects of the Invention The prepreg of the present invention has a woven fabric on one side of the unidirectional prepreg in which the weft is made of reinforcing fiber yarn and the warp is made of low melting point polymer yarn. By selecting the weft direction and foot, it is possible to obtain the desired reinforcing effect in the width direction of the unidirectional prepreg, which is different from conventional scrims. Unlike cross-laminated prepreg, there is no lack of reinforcing effect in the width direction.

Moreover, since the warp yarns simply maintain the arrangement of the weft yarns until the prepreg is used to form FRP, the number of such phrases can be minimized, and the increase in weight of FRP can be reduced by 1.
Not only does it never occur, but it also melts during molding, so a homogeneous FRP can be obtained.

Therefore, for example, if this is used as a molding material for fishing rods or golf shafts, not only can the strength and modulus of elasticity be improved, but also the condition can be controlled arbitrarily, and the weight can be reduced.

In addition, since a pre-woven fabric with excellent handling properties is attached, it is possible to
Unlike the prepreg described in JP-A-56-162642, there is no need to go through the trouble of arranging reinforcing fibers at arbitrary intervals in the width direction of the unidirectional prepreg. There is no need to prepare two unidirectional prepregs in advance, unlike the prepregs described in Japanese Patent Publication No. 58-212936, so the prepreg of the present invention can be manufactured at low cost.

[Brief explanation of drawings]

The drawing is a schematic front view showing how the prepreg of the present invention is being manufactured. 1: Strand of reinforcing fiber 2: Release paper 3: Release paper 4: Hot plate 5: Impregnated roll 6: Take-up roll 7: Unidirectional prepreg 8: Fabric 9: Adhesive roll 10: Take-up roll 11: Winding core

Claims (1)

[Claims] On one side of the unidirectional prepreg, which is made by impregnating resin with reinforcing fibers drawn parallel to each other in a sheet shape in one direction, a fabric whose wefts are made of reinforcing fiber yarns and whose warps are made of low-melting polymer yarns is attached. The prepreg is formed by adhering the reinforcing fibers in the direction in which they are aligned.