JPH03230912A - Prepreg and its manufacture - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is used for molding fiber-reinforced composite materials such as fiber-reinforced plastics using carbon fibers and metal fibers such as boron fibers and titanium fibers. This invention relates to prepreg and its manufacturing method.

[Prior art] Since the fiber diameter of metal fibers such as boron fibers and titanium fibers is much larger than that of carbon fibers, the resin is It cannot be formed like a unidirectional carbon fiber prepreg formed by impregnation. Therefore, metal fibers are arranged in one direction on glass fiber scrim cloth as a carrier and temporarily bonded to form a laminated sheet, or a prepreg is created by impregnating a laminated sheet of scrim cloth and metal fibers with resin. It is intended to be used in the molding of fiber-reinforced composite materials.

[Problems to be Solved by the Invention] However, the use of metal fibers and metal fiber reinforced composite materials as described above have the following problems.

In other words, the most important feature of fiber-reinforced composite materials is that they have high specific strength and specific modulus.

It is known that it is best to use carbon fibers as reinforcing fibers in fishing rods and golf shafts that require particularly high specific strength and specific modulus. Therefore, when it comes to fishing rods and golf shafts made of fiber-reinforced composite materials, apart from the cheap ones, almost all of them are carbon 1.
11iIft is used, but there are some trends in these, and every year there is a demand for something new in terms of appearance, etc., and metal fibers, ceramic fibers, aramid fibers, metal whiskers, etc. are used in combination. Efforts have been made to do this, or change the paint. However, on the other hand, the specific strength and specific modulus must not decrease due to the combined use of other fibers.

By the way, in the conventional method of using metal fibers in combination with glass fiber scrim cloth, the glass fiber scrim cloth is also buried in the fiber reinforced composite material, but glass fiber has poor strength, elastic modulus, etc. This is far inferior to metal fibers and carbon fibers, so when comparing fiber-reinforced composite materials with the same date of reinforcing fiber or fiber-reinforced composite materials of the same weight, those that use metal fibers in combination with carbon fibers are the same as those that use only carbon fibers. Compared to this, the specific strength and specific modulus of elasticity are smaller. Increasing the amount of metal fibers inevitably increases the amount of glass fiber scrim cloth, reducing the weight of the structure.
There is a limit to miniaturization (wall thickness, etc.), and conversely, if you reduce the amount of glass fiber scrim cloth in order to reduce the weight of the structure, you will inevitably also reduce the amount of metal fiber. In other words, glass fiber scrim cloth is not necessary to greatly improve the properties of fiber-reinforced composite materials, and it actually gets in the way of the design of fiber-reinforced composite structures. This is a major constraint in design.

The present invention focuses on the problems in the prior art as described above, and provides a metal fiber prepreg and a method for manufacturing the same that does not use glass fiber scrim cloth, which is not essentially necessary for improving properties, Significantly expands the degree of freedom in the design of fiber-reinforced composite structures.
The purpose is to simultaneously achieve improvements in strength, etc., and reduction in weight.

[Means for Solving the Problems] The prepreg of the present invention that meets this objective comprises a metal fiber sheet formed by aligning metal fibers parallel to each other in one direction in a sea I-shape, and carbon fibers arranged parallel to each other and aligned in a sea I-shape. It consists of prepreg sheets that are aligned in a sheet form and impregnated with resin, which are laminated so that the fibers are aligned in the same direction, and are bonded to each other by the resin of the prepreg sheets.

The most preferred bonding pattern between the metal fiber sheet and the prepreg sheet is a sandwich type in which the metal fiber sheet is sandwiched between two prepreg sheets from both sides. However, if the metal fiber layer is to be placed on the surface of a fiber-reinforced composite material structure to be molded, etc., a two-layer structure pattern of a metal fiber sheet and a prepreg sheet may be used. Good too.

In such prepreg, a pre-formed unidirectional carbon fiber prepreg sheet is used as a carrier for the metal fiber sheet, and the metal fiber sheet and the carbon fiber prepreg sheet are bonded using the resin of the carbon fiber prepreg. be done. Glass fiber scrim cloth is not used at all, and carbon fiber, which has higher strength and modulus of elasticity than glass fiber, is used, so the properties of fiber reinforced composite structures are definitely improved compared to when glass fiber scrim cloth is used. be enhanced.

In addition, we have a large degree of freedom in manufacturing the carbon fiber prepreg sheet itself, the basis weight of the reinforcing fibers and resin, the thickness of the prepreg sheet, etc. Since there is essentially no element that would increase the amount of material (glass fiber scrim cloth) that contradicts weight reduction and strength improvement, the basis weight of metal fibers, the basis weight of carbon fiber of carbon fiber prepreg sheet relative to that, and the resin A large degree of freedom is obtained with respect to the date of , which greatly expands the degree of freedom in the design of fiber-reinforced composite structures.

Such prepreg is manufactured as follows.

The prepreg sheet is made by aligning metal m-fiber sheets and carbon fibers parallel to each other in a sheet shape and impregnating them with resin, and winding the prepreg sheet around a drum so that the direction of alignment of the carbon fibers is in the circumferential direction of the drum. (The drum is rotated, and the metal fibers are sequentially wound adjacent to each other while applying tension on the prepreg sheet on the rotating drum, and are immersed in the resin of the prepreg sheet. This is a method of joining the upper metal fibers to each other.

When the prepreg has a sandwich-type three-layer structure in which carbon fiber prepreg sheets are laminated on both sides of a metal fiber sheet, the first layer is made by aligning the carbon fibers parallel to each other in a sheet shape and impregnating them with resin. The first prepreg sheet is wound around the drum so that the alignment direction of the carbon fibers is in the circumferential direction of the drum, the drum is rotated, and the metal fibers are tensioned onto the first prepreg sheet on the rotating drum. The first prepreg sheet and the metal fibers on the first prepreg sheet are bonded to each other by wrapping them adjacently in sequence and sinking them into the resin of the first prepreg sheet 1. The laminated sheet of the first prepreg sheet and metal fibers obtained in step 1 was removed from the drum, and on the metal fiber side of the laminated sheet, the carbon fibers were aligned parallel to each other in a sheet shape, and the resin was applied. The impregnated second prepreg sheets are superimposed in the same direction as the alignment direction of the carbon fibers or the alignment direction of the metal fibers, and the laminated sheet and the second prepreg sheet are bonded to each other. Consists of methods.

In the manufacturing method according to the present invention, a so-called drum winding method is used. Since metal fibers are basically monofilaments, it is possible to apply a certain amount of high tension when they are sequentially wound onto a carbon fiber prepreg sheet that has been wound on a drum. Since the prepreg sheet on the drum is preferably heated to soften the resin appropriately, the tensioned metal fibers easily sink into the resin of the prepreg sheet and are held by the resin. That is, the carbon fibers and metal fibers aligned in the same direction are efficiently held in a sheet shape by the same resin. Therefore, carbon fibers and metal fibers are formed into a sheet-like prepreg without increasing the basis weight of the resin, and the prepreg is used for molding a fiber-reinforced composite material structure.

U example] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a process for manufacturing a prepreg according to an embodiment of the present invention, FIG. 3 shows a prepreg manufactured by the process shown in FIG. 1, and FIG. 2 shows a process for manufacturing a prepreg according to an embodiment of the present invention. FIG. 4 shows the prepreg manufactured by the steps shown in FIG.

In FIG. 1, reference numeral 1 indicates a first prepreg sheet that has been made into a sheet-like prepreg by impregnating a reinforcing fiber sheet in which fiber bundles of carbon fibers 2 are arranged parallel to each other in a sheet shape, and then impregnated with a resin. and is supported on the release sheet 3. This first prepreg sheet 1 is wound around the outer circumferential surface of the drum 4 by at least one circumference of the drum, with the direction in which the carbon fiber bundles are aligned in the circumferential direction of the drum.

Known methods can be used to manufacture this carbon fiber prepreg sheet 1 and a second carbon fiber prepreg sheet to be described later. For example, carbon fiber reinforced fibers arranged in a sheet between two release sheets each carrying a resin (e.g., a thermosetting resin such as a B-stage epoxy resin or an unsaturated polyester resin) on at least one surface thereof. A prepreg is created by sandwiching the sheets and applying pressure and heat using, for example, press rolls to transfer and impregnate the reinforcing fiber sheet with resin, then peel off one release sheet and roll the prepreg together with the other release sheet. Alternatively, the reinforcing fiber sheet and the support sheet are immersed in a resin solution diluted with an appropriate solvent.
Manufactured by a method that involves lifting and heating to remove the solvent.

The drum 4 on which the prepreg sheet 1 is wound is rotated at low speed in the direction of the arrow by a drive source (motor) 6 via a suitable speed reducer 5. At the same time, the drum surface temperature is controlled by the drum temperature control means 7, and the prepreg sheet 1 is heated to a predetermined temperature through the temperature control. In this embodiment, the drum temperature control means 7 for this heating control circulates a heat medium within the drum 4 using a pump 8, and controls the temperature of the circulating heat medium with a heat medium temperature control means 9. However, for example, a method may be adopted in which a heater is embedded within the drum 4 and the temperature of the heater is controlled.

By heating the prepreg sheet 1, the resin of the prepreg sheet 1 is softened appropriately.

On the prepreg sheet 1 on the drum 4, metal fibers 10 such as boron fibers and ditan fibers are successively wound adjacent to each other while applying tension.

The metal fibers 10 are continuously unwound 2 from the package 11, and the metal 1. There is a moderate amount of tension in @io. The metal fibers 10 being sent out are passed through a guide 13 located between the package 11 and the drum 4. Guide 13
is fixed, for example, to a nut 1 to a means 15 screwed together with a ball screw 14, and is reciprocated in a direction along the drum axis together with the nut means 15 by rotating the ball screw 14 in the normal or reverse direction. The ball screw 14 is rotationally driven at a predetermined low speed by a reversible motor 16 (for example, a reversible gear motor). As the guide 14 moves, the metal edge #1 is wrapped around the prepreg sheet 1.
The metal fibers 10 are sequentially fed in the direction along the drum axis, and the metal fibers 10 are sequentially wound adjacent to each other. The width of the wrapping of the metal fibers 10 on the prepreg 1 may be substantially the same as that of the prepreg sheet 1. The number of layers of metal fiber 10 wrapped around prepreg sheet 1 is as follows:
Any number of layers greater than or equal to one is possible.

3 Appropriate tension is applied to the metal edge 110 being wrapped, and the prepreg sheet 1 on the drum 4 is heated to soften the resin appropriately, so the metal fibers 10 sink into the softened resin. In some cases, it may become buried in the resin. As a result, the wrapping is done after the metal fiber 1
0 is held in a sheet shape by the resin of the prepreg sheet 1.

A laminated sheet of metal fibers 10 and prepreg sheet 1, on which a predetermined amount of metal IIi fibers 10 have been wound, is placed on a drum 4.
When removed from the sheet, a prepreg 17 in the form of a sheet as shown in FIG. 3 is obtained.

This prepreg 17 is made by laminating a metal fiber sheet 18 and a carbon fiber reinforcing fiber sheet 19, and both elastic fiber sheets 18.19 are held together by the same resin used in the prepreg sheet 1. This prepreg is in the form of a laminated sheet.

Such a two-layer prepreg 17 has metal fibers 10
This is suitable when it is desired to arrange the layer at a specific position (for example, on the surface side of the fiber-reinforced composite material structure). Unlike conventional methods, there is no need to use glass fiber scrim cloth 4, so the degree of freedom in designing fiber-reinforced composite materials is greatly expanded, and the amount of resin used in Prepreg Sea 1 to 1 can be reduced to the minimum required amount. Since the carbon fiber 2 has a large degree of freedom in terms of its basis weight, weight reduction can be achieved at the same time.

The prepreg according to the present invention can be made more stable by forming it into a Sandwich-type three-layer structure in which carbon fiber prepreg sheets are laminated on both sides of a metal fiber sheet.

As shown in FIG. 3, a second carbon fiber prepreg sheet 20, which is the same as or equivalent to the prepreg sheet 1, is placed on the metal fiber side surface of the prepreg 17 in FIG. 2 obtained by the method shown in FIG. are superimposed on each other with the direction in which the carbon fiber bundles are drawn in the same direction as the direction in which the metal fibers 10 are drawn. The second prepreg sheet 20 is also supported on the release sheet, and in the superimposed state, the release sheet of the first prepreg sheet 1 and the release sheet of the second repreg sheet 20 are located on both sides. There is. This polymer 21 is
A calender 5 equipped with a heating roll 22 and an h1 pressure roll 23 is passed through a device 24 where it is heated and pressurized from both sides. By this heating and pressurization, the prepreg 17 and the second prepreg sheet 20 are joined, and a three-layered prepreg 25 shown in FIG. 4 is obtained.

This prepreg 25 has a Zandwich structure in which the metal fiber sheet layer 18 of the metal fibers 10 is sandwiched from both sides by the reinforcing fiber sheet layers 19 and 26 of carbon fibers containing resin, so that the metal fibers 10 are further formed in a sheet form. It will be held firmly. Therefore, it goes without saying that the degree of freedom in designing fiber-reinforced composite materials is greatly expanded, and when molding a fiber-reinforced composite material structure, the prepreg 25
This makes it easier to handle when cutting into predetermined dimensions or winding into a predetermined shape, resulting in improved workability. Other operations are similar to those described in FIGS. 1 and 2.

[Effects of the Invention] As explained above, when the prepreg and the manufacturing method thereof of the present invention are used, the prepreg sheet]
The metal fibers are held in a predetermined sheet form using the resin from ~6, and there is no need to use glass fiber scrim cloth as in the past, making it easier to mold metal fiber reinforced composite structures. , while achieving thinner walls, it is possible to greatly expand the degree of freedom in design regarding strength, elastic modulus, etc., and it is possible to simultaneously achieve weight reduction and improvement in strength, etc.

[Brief explanation of drawings]

Fig. 1 is a schematic perspective view of a drum winding device showing a prepreg manufacturing method according to an embodiment of the present invention, and Fig. 2 shows a case where the prepreg obtained by the method shown in Fig. 1 is further made into a three-layer prepreg. 3 is a partially cutaway perspective view of the prepreg obtained by the method shown in FIG. 1; FIG. 4 is a partially cutaway perspective view of the prepreg obtained by the method shown in FIG. 2. Figure, is. 1... First prepreg sheet 7 2... Carbon fiber 3... Release sheet 4... Drum 6... Motor 7. ...Drum temperature control means 9... Heat medium temperature control means 10 ... Metal fiber 11 ... Package 12 ... Brake device 13 ... ... Kite 14 ... Ball screw 16 ... Reversible motor 17 ... Prepreg 18 ... Metal fiber sheet 19.26 ... Carbon fiber reinforced fiber sea 20・
... Second prepreg sheet 21 ... Polymer 22 ... Heating roll 23 ... Pressure roll 24 ... Calender device 8 1 ~ 25・・・Prepreg patent applicant Toshi Co., Ltd. 9

Claims (1)

[Claims] 1. A metal fiber sheet made by aligning metal fibers parallel to each other in one direction in a sheet shape, and a prepreg made by aligning carbon fibers parallel to each other in a sheet shape and impregnated with a resin. A prepreg characterized in that the sheets are laminated so that the fibers are aligned in the same direction, and are bonded to each other by the resin of the prepreg sheet. 2. A prepreg sheet made by aligning carbon fibers parallel to each other in a sheet shape and impregnating them with resin is wrapped around a drum so that the direction in which the carbon fibers are aligned is in the circumferential direction of the drum, and the drum is rotated. The metal fibers are sequentially wound adjacent to each other while applying tension onto the prepreg sheet on the drum, and the metal fibers are immersed in the resin of the prepreg sheet to bond the prepreg sheet and the metal fibers on the prepreg sheet to each other. A method for producing prepreg, characterized by: 3. Wrap the first prepreg sheet, which is made by aligning carbon fibers parallel to each other in a sheet shape and impregnating them with resin, on a drum so that the direction in which the carbon fibers are aligned is in the circumferential direction of the drum. On the first prepreg sheet on the rotating drum, metal fibers are sequentially wound adjacent to each other while applying tension, and the metal fibers are embedded in the resin of the first prepreg sheet to form the first prepreg sheet. and the metal fibers on the first prepreg sheet are mutually bonded, the laminated sheet of the first prepreg sheet and metal fibers obtained by bonding is removed from the drum, and the metal fiber side surface of the laminated sheet is , a second prepreg sheet made by aligning carbon fibers parallel to each other in a sheet shape and impregnating them with a resin is stacked so that the alignment direction of the carbon fibers is the same as the alignment direction of the metal fibers, A method for manufacturing a prepreg, comprising joining the laminated sheet and a second prepreg sheet to each other.