JP2021123041A - preform - Google Patents

Abstract

To provide a preform of an effective prepreg having good mechanical characteristics at molding end part and excellent deburring property.SOLUTION: A preform involves a reinforcement fiber and a thermosetting resin and comprises a laminate of two pieces or more of prepreg cut bodies having prescribed shapes, wherein the unidirectional prepreg comprises a continuous fiber as the reinforcement fiber and is a cut prepreg including a plurality of cuts crossing the continuous fiber; the preform includes a laminate body including one or more pieces of the prepreg cut body, and one or more pieces of an extending cut body comprising the unidirectional prepreg including a folded extending part covering at least a part of an outer peripheral end part of the laminate body over the whole body in its laminate thickness direction, and the thickness of the laminate body is larger than or equal to the thickness of the extending cut body.SELECTED DRAWING: Figure 1

Description

The present invention relates to a laminate made of a prepreg mainly composed of reinforcing fibers and a thermosetting resin, which can be used for compression molding such as press molding. More specifically, the present invention can be suitably used for automobile structural materials, aircraft members, sports equipment, etc., which can obtain a molded product having excellent mechanical properties at the end of the molded product and further excellent deburring property. , It is about preform by prepreg.

Since fiber reinforced plastics are lightweight, have high strength, and have high rigidity, they are used in a wide range of fields such as sports / leisure applications such as fishing rods and golf shafts, and industrial applications such as automobiles and aircraft. A method of using a prepreg, which is an intermediate material obtained by impregnating a fiber reinforcing material made of long fibers such as reinforcing fibers with a resin, is preferably used for producing a fiber reinforced resin. A molded product made of a fiber reinforced resin can be obtained by cutting the prepreg into a desired shape, laminating and shaping the prepreg, and heat-curing the prepreg in a mold. (For example, Patent Document 1)

In addition, there is also a method for manufacturing fiber reinforced plastics that exhibits excellent mechanical properties and low variation while having good fluidity and complex shape followability by using a notched prepreg with a notch inserted in the prepreg. do. (For example, Patent Document 2)

JP 2015-143343 Japanese Unexamined Patent Publication No. 2010-30193

However, in a method in which a prepreg is cut into a desired shape as illustrated in Patent Document 1, then laminated and shaped to form a preform, and compression molded in a die, the prepreg is simply laminated in a plane and pressed. In the conventional method of molding, the reinforcing fibers invade the parting line of the mold together with the resin, and hard burrs containing the fibers are generated at the outer peripheral end of the molded product. Mechanical post-processing is required to remove this burr, which requires labor and time, and may require skillful techniques. Further, especially when the end shape of the molded product has a change in wall thickness, prepregs cut into different shapes may be laminated in a stepped shape and press-molded, but when the prepreg does not flow, the stepped portion is rich in resin. There was a problem that it was generated and the mechanical properties and design were deteriorated.

On the other hand, in the same compression molding method, the method of Patent Document 2 using a cut prepreg having excellent fluidity is aimed at achieving both mechanical properties, fluidity, and low variability, and is an outer peripheral end portion of a molded product. There is no focus on post-processing of burrs that occur in. Further, although the resin richness is eliminated by the fiber flow to the stepped portion of the preform, the mechanical properties are excellent, but there is room for improvement in the fiber alignment at the stepped portion.

Therefore, with the prior art, it has been extremely difficult to obtain a fiber-reinforced resin molded product having both good mechanical properties at the end of the molded product and excellent deburring property.

Therefore, an object of the present invention is to pay attention to the above-mentioned problems and to provide a prepreg preform which is effective for good mechanical properties and excellent deburring property at the end of a molded product.

The present invention for solving the above problems has any of the following configurations.
(1) A preform in which two or more prepreg cut bodies composed of a unidirectional prepreg having a predetermined shape containing reinforcing fibers and a thermosetting resin are laminated, and the unidirectional prepreg is a continuous fiber. It is a cut prepreg having a plurality of cuts that cross the continuous fiber, and the preform is a laminate having one or more prepreg cut bodies and an outer peripheral end portion of the laminate in the thickness direction of the laminate. It has one or more extended cutting bodies made of the one-way prepreg having at least a part of the folded extending portion covering the whole, and the thickness of the laminated body is equal to or larger than the thickness of the extending cutting body. A preform that features.
(2) It is characterized in that at least a part of the outer peripheral end portion of the laminated body is covered over the entire area in the thickness direction of the laminated body, and a part of one surface of the laminated body is covered. The listed preform.
(3) The preform according to (2), wherein the laminated body has a stepped portion, and at least a part of the stepped portion is covered with the folded-back extending portion.
(4) 2. The preform described in either.
(5) The preform according to any one of (1) to (3), wherein the extended cut body is arranged on the other surface of the laminated body.
(6) A cover cut body having a fiber direction equal to the fiber direction of the folded extending portion is arranged on the surface of the folded extending portion or between the folded extending portion and the laminated body. , (1) to (5).
(7) A cover cut body having a fiber direction equal to the fiber direction of the folded extending portion covers the surface of the folded extending portion or one of the surfaces between the folded extending portion and the laminated body. The preform according to any one of (2) to (5), wherein the preform is arranged over a region and a region covering the laminated thickness direction of the laminated body.

According to the preform according to the present invention, even when a fiber-reinforced resin molded product is obtained by press molding, the laminated structure and fiber alignment of the end portion of the molded product can be maintained, and the deburring of the molded product after press molding can be maintained. Deburring can be done easily in a short time.

It is a figure which shows an example of the unidirectional prepreg, the prepreg sheet, and the extended cutting body used in this invention. It is a figure which shows an example of the prepreg sheet, the laminated body, the extended cutting body, and the preform of this invention, and the manufacturing process thereof. It is a figure which shows an example of the extended cutting body of this invention. It is a figure which shows an example of the positional relationship between the folded-out extending portion and the laminated body of this invention. It is a figure which shows another example of the positional relationship between the folded-out extending portion and the laminated body of this invention. It is a figure which shows an example of the positional relationship of the cover cut body of this invention, a laminated body, and a folded-out extending portion. It is a figure which shows another example of the positional relationship of the cover cut body, the laminated body, and the folded-out extending portion of this invention. It is a figure which shows an example of the prepreg sheet of this invention, the laminated body which has a step part, the extended cut body, and the preform, and the manufacturing method thereof.

When a three-dimensional complex shape is desired as a molded product using a fiber reinforced resin, generally, a plurality of prepreg sheets cut into the desired shape are laminated to prepare a preform suitable for the product shape. A molded product is obtained under predetermined molding conditions. The preform of the present invention is a product obtained by laminating two or more prepreg cut bodies made of a unidirectional prepreg having a predetermined shape, including reinforcing fibers and a thermosetting resin, which are used in manufacturing a molded product in this way. A reform, the unidirectional prepreg is a cut prepreg in which the reinforcing fibers are continuous fibers and has a plurality of cuts across the continuous fibers, and the preform is a laminate having one or more prepreg cut pieces. And one or more extended cutting bodies made of a unidirectional prepreg having at least a part of a folded extending portion that covers the outer peripheral end portion of the laminated body over the entire thickness direction of the laminated body, and the thickness of the laminated body. Is a preform characterized by having a thickness equal to or greater than the thickness of the extended cutting body.

Next, the details of the embodiment of the present invention will be described.

[One-way prepreg]
The unidirectional prepreg used as a material for obtaining the prepreg cut body used in the present invention is composed of reinforcing fibers and a thermosetting resin. As the form of the prepreg, for example, a wide sheet-like material as shown in FIG. 1 or a narrow tape-like material can be mentioned as a preferable example.

As the reinforcing fibers constituting the unidirectional prepreg, continuous fibers arranged in the same direction can be used.

In a unidirectional prepreg using continuous fibers as reinforcing fibers, it is also preferable to make a plurality of cuts 154 so as to cross the continuous fibers (hereinafter, such a unidirectional prepreg is referred to as a cut prepreg). Further, the cut prepreg can be used in combination with a normal unidirectional prepreg having no cut, which is simply a continuous fiber of the reinforcing fiber.

When a pressing force is applied when forming the cut prepreg, the cut prepreg is likely to be opened or displaced at the cut insertion portion, and the extensibility of the cut prepreg in the reinforcing fiber direction is improved. Further, the cut insertion portion is opened by the flow during compression molding, and the fiber bundles of the reinforcing fibers are separated from each other, so that the cut prepreg becomes flexible and the fluidity is enhanced. By making the cut prepreg flowable in this way, the reinforcing fibers reach the end of the molded product, the area where the resin is rich is reduced, and a molded product having excellent mechanical properties and appearance can be obtained. can. From the viewpoint of fluidity, it is preferable that the cut is made in the entire area in the thickness direction of the cut prepreg.

The cutting pitch is preferably 3 mm or more and 100 mm or less, more preferably 5 mm or more and 75 mm or less, and further preferably 10 mm or more and 50 mm or less. By setting the length of the reinforcing fiber to the lower limit of the above preferable range or more, the molded product exhibits sufficient mechanical properties. On the other hand, by setting the length of the reinforcing fibers to be equal to or less than the upper limit of the above preferable range, each component of the laminated body can obtain sufficient fluidity at the time of molding.

The cut length varies depending on the cutting direction and the angle formed by the main axis direction of the reinforcing fibers of the cut prepreg, but the projected length of the reinforcing fibers in the fiber orthogonal direction is preferably 0.05 mm or more and 25 mm or less. It is more preferably 0.1 mm or more and 10 mm or less, and further preferably 0.15 mm or more and 5 mm or less. By setting the cut length to be equal to or greater than the lower limit of the above preferable range, the opening amount of the cut insertion portion is increased, and the components of the laminated body exhibit sufficient fluidity. On the other hand, when the cut length is set to be equal to or less than the upper limit of the above preferable range, the opening of the cut insertion portion is suppressed, and a molded product having excellent appearance quality and mechanical properties can be obtained.

The volume content of the reinforcing fiber preferably as a unidirectional prepreg is preferably 40% or more and less than 80%, more preferably 45% or more and less than 75%, and further preferably 50% or more and less than 70%. As described above, the unidirectional prepreg and the cut prepreg are excellent in filling efficiency of the reinforcing fibers, and are therefore suitable for drawing out the reinforcing effect of the reinforcing fibers, and are effective in improving the rigidity of the molded product. ..

The amount of reinforcing fibers contained in the unidirectional prepreg, a basis weight of the reinforcing fibers in the case of the sheet is preferably less than 50 g / m ² or more 1000 g / m ^2. In a cut prepreg using a small piece of a reinforcing fiber bundle impregnated with a thermosetting resin or a chopped fiber bundle as a precursor, if the amount of graining is too small, pores in the surface of the cut prepreg in which the reinforcing fiber does not exist are generated. In some cases. By setting the basis weight to be equal to or higher than the lower limit of the above preferable range, it becomes possible to eliminate pores that are weak parts in the fiber reinforced resin. Further, if the basis weight is less than the upper limit of the above preferable range, heat can be uniformly transferred to the inside in the preheating of molding. ^{The basis weight is more preferably 100 g / m 2} or more and less than 600 g / m ² , and further preferably 150 g / m ² or more and less than 400 g / m ² in order to achieve both structural uniformity and heat transfer uniformity. be. To measure the basis weight of the reinforcing fibers, a region of 10 cm square is cut out from the sheet-like material of the reinforcing fibers, the mass thereof is measured, and the weight of the region is divided by the area to derive the basis weight of the region. This measurement is performed 10 times for different regions of the sheet-like material of the reinforcing fibers, and the average value is adopted as the basis weight of the reinforcing fibers.

As the unidirectional prepreg, a unidirectional prepreg containing a portion where the thermosetting resin is not impregnated in the reinforcing fiber can also be used. Here, the unimpregnated portion is a portion where the thermosetting resin does not adhere to one or both of the surface and the inside of the reinforcing fiber. The resin-unimpregnated portion of the unidirectional prepreg is impregnated with the thermosetting resin that has flowed from another portion through compression molding such as press molding, and can exhibit desired characteristics as a healthy portion.

As the reinforcing fiber used for the unidirectional prepreg, for example, carbon fiber, glass fiber, aramid fiber, alumina fiber, silicon carbide fiber, boron fiber, metal fiber, natural fiber, mineral fiber and the like can be used, and these can be used. Can be used alone or in combination of two or more. Among them, carbon fibers such as PAN-based, pitch-based and rayon-based are preferably used from the viewpoint of high specific strength and specific rigidity and weight reduction effect. Further, from the viewpoint of increasing the conductivity of the obtained molded product, reinforcing fibers coated with a metal such as nickel, copper or ytterbium can also be used.

Examples of the thermosetting resin used for the unidirectional prepreg include unsaturated polyester resin, vinyl ester resin, epoxy resin, phenol resin, urea-melamine resin, maleimide resin, polyimide resin and other resins, and copolymers thereof. , Modified products, and resins blended with at least two of these. Of these, epoxy resins are preferably used from the viewpoint of the mechanical properties of the obtained molded product. Further, since the unidirectional prepreg is cured in the molding step, the glass transition temperature of the thermosetting resin used in the uncured state is preferably 80 ° C. or lower, more preferably 70 ° C. or lower, and further preferably 60 ° C. It is below ° C.

[Prepreg cut body]
The prepreg cutting bodies 111 to 113 used in the present invention are a sheet-shaped unidirectional prepreg cut into a predetermined shape, and a sheet-shaped unidirectional prepreg cut into a tape shape and then arranged in a predetermined shape. A tape-shaped unidirectional prepreg that has been cut or cut into a predetermined shape. Further, a prepreg cut body obtained by laminating a plurality of layers of the sheet-shaped unidirectional prepreg shown in FIG. 1 and then cutting the prepreg into a desired shape can also be used. When laminating in a plurality of layers, at least one unidirectional prepreg is laminated in different fiber directions to be reinforced as a fiber reinforced resin in a plurality of directions, so that preferable mechanical properties can be exhibited.

[Laminate]
The laminate used in the present invention is a laminate of prepreg cut bodies. When the fiber directions of the layers of the prepreg cut body constituting the laminated body are different from each other, the fiber-reinforced resin is reinforced in a plurality of directions, which is preferable in terms of mechanical properties. Therefore, it is also preferable that the layers of the plurality of prepregs are arranged so that the fiber orientations of the two adjacent prepregs are different from each other, at least in part. Among them, since the fiber-reinforced resin usually has better mechanical properties in the fiber direction than the mechanical properties in the fiber orthogonal direction, for example, the fiber orientations of the two adjacent unidirectional prepregs may be arranged so as to be orthogonal to each other. preferable. If, for example, the fiber directions of the unidirectional prepregs of two adjacent layers of the prepreg layers composed of a plurality of layers are arranged so as to be orthogonal to each other, the fiber orthogonal directions of one layer and the fiber directions of the other layer become the same direction. Therefore, good mechanical properties can be efficiently exhibited.

The thickness of the laminate used in the present invention is preferably 0.4 mm or more and 50 mm or less in the thickest portion, more preferably 0.8 mm or more and 25 mm or less, and further preferably 1.6 mm or more 12 It is 5.5 mm or less. When the thickness is within the above preferable range, it becomes easy to uniformly transfer heat to the inside of the laminate, and by extension, a molded product having an excellent appearance can be obtained.

[Deferred cutting body]
The extended cutting body 120 used in the present invention is a sheet-shaped unidirectional prepreg cut into a predetermined shape, or a tape-shaped unidirectional prepreg arranged in a predetermined shape. Further, those obtained by laminating a plurality of layers and then cutting them into a desired shape can also be used.

The extended cutting body has a folded extending portion 121 extending in the normal direction from the bending line 124 of the extending cutting body which is the outer peripheral end portion 105 of the preform shown in FIG. That is, the folded extending portion is a region of the extended cutting body that is folded around the outer peripheral end portion 105 of the final preform as a boundary. The angle 300 formed by the fiber direction 1520 of the folded extending portion and the extending direction 1210 of the folded extending portion is shown in FIG.

When the end of the preform has a curved shape, the extending portion extends in the normal direction from the bending line 124 of the extending cut body which is the outer peripheral end of the curved preform shown in FIG. It has a part 121. That is, in such an extended cutting body, the extending direction of the folded extending portion changes depending on the position, and the angle 300 formed by the fiber direction 1520 of the folded extending portion and the extending direction 1210 of the folded extending portion is also distributed. have.

Further, the folded-back extending portion can be folded back at a position other than the position corresponding to the end portion 115 of the laminated body. For example, even when the end portion of the laminated body has a curved shape, it can be folded back so that the end portion shape of the preform has a linear shape, and vice versa.

The extending length of the folded-back extending portion varies depending on the size of the final preform and the number of laminated preforms, but when the folded-back portion is folded, the outer peripheral end portion of the laminated body is covered over the entire thickness in the laminated thickness direction. In addition, it is preferable that the length is equal to or larger than the thickness of the end portion of the laminated body with respect to the extending direction.

The extended cut body has at least a part of a folded extended portion that covers the outer peripheral end portion of the laminated body over the entire thickness direction of the laminated body in the final preform. In particular, it is preferable to have a position corresponding to a region of a product having a complicated shape and difficult to deburr, or a position desired to suppress disturbance of fiber alignment from the viewpoint of deburring property and mechanical properties of the end of the molded product.

[preform]
The preform of the present invention is composed of a laminated body and a stretched cut body.

In the preform that is not folded back at the extending part (called a conventional preform), the preform is deformed according to the shape of the mold cavity due to the pressure during compression molding, and the fibers and resin at the end of the preform are removed. It is filled in the mold cavity. When the conventional preform is formed of layers of unidirectional prepregs laminated so as to be oriented in a plurality of fiber directions, the unidirectional prepreg has a flow anisotropy that facilitates flow in the fiber orthogonal direction rather than the fiber direction. Therefore, first, the flow of the unidirectional prepreg layer is generated in the fiber orthogonal direction, and then the flow of the unidirectional prepreg layer is dragged by the shearing force between the layers and the prepreg layer flows in the direction other than the fiber orthogonal direction. Although it depends on the resin viscosity at the time of pressurization and the resin viscosity distribution in the stacking thickness direction of the preform, a plurality of prepreg layers extend or flow from the outer peripheral end of the conventional preform, and the fibers and the resin in the multiple fiber directions. Outflows from the parting line of the mold cavity, forming burrs consisting of fibers and resins in multiple fiber directions.

Further, although it depends on the amount of burrs flowing out of the mold cavity, in the conventional preform, the outer peripheral end portion of the preform flows locally to the parting line of the mold cavity, so that the preform end portion The fiber alignment in the vicinity may be disturbed.

On the other hand, in the preform of the present invention, since the outer peripheral end portion of the laminated body is covered with the folded extending portion, the region other than the folded extending portion and the folded extending portion of the extended cutting body is gold during compression molding. It is pressed by the mold cavity to give resistance to the end of the laminate and suppress the outflow of the end of the laminate to the outside of the mold cavity. In particular, if the folding boundary side of the folding extension portion of the preform is arranged on the parting line side of the mold cavity, the tip of the folding extension portion is separated from the parting line of the mold cavity, so that friction during pressing is performed. This is preferable because resistance increases and burrs are suppressed. In addition, since the degree of flow of the prepreg layer in each direction changes depending on the resin viscosity during pressurization and the resin viscosity distribution in the stacking thickness direction, it is important to cover the end of the laminate over the entire stacking thickness direction. be.

Further, even when the preform flows out of the mold cavity due to compression molding, the folded-back extending portion closer to the parting line of the mold cavity flows out earlier than the end portion of the laminate to form burrs. do. As a result, most of the fibers of the burr are in the fiber direction of the folded and extended portion. Since the fiber-reinforced resin has anisotropy that the strength in the fiber direction is higher than that in the fiber orthogonal direction, the resistance applied to the tool during post-machining becomes constant due to the single fiber direction of the burr. Vibration is suppressed, and not only workability is improved, but also tool life is improved. Further, even when the outer peripheral end portion of the preform flows locally to the parting line of the mold cavity, the folded-back extending portion serves as a buffer, and the fiber alignment at the end portion of the laminate is less likely to be disturbed.

In the preform of the present invention, it is important that the thickness of the laminated body is equal to or larger than the thickness of the extended cut body. The extended cutting body of the present invention suppresses the disorder of the fiber alignment of the laminated body. However, with such a configuration, the region where the disorder of the fiber alignment is suppressed occupies more than half of the preform end portion. It is preferable that the mechanical properties are kept good.

The preform of the present invention as described above may be shaped into a three-dimensional shape such as a curved surface shape according to the shape of the molded product as long as the laminated structure is maintained.

As shown in FIG. 4, the preform of the present invention further covers at least a part of the outer peripheral end portion 115 of the laminated body over the entire area in the laminated thickness direction, and one of the surfaces 117 of the laminated body. It is preferable to cover the portion. Here, the one surface of the laminated body means a surface on which the regions other than the folded and extended portion of the extended cutting body are not laminated. At this time, the end portion 125 of the folded-back extending portion reaches one surface 117. With such a configuration, during compression molding, the region other than the folded overhanging portion and the folded over extending portion of the extended cutting body is pressed by the mold cavity to give resistance to the end of the laminate, and the end of the laminate Can be suppressed from flowing out of the mold cavity.

In the preform of the present invention, as shown in FIG. 5, it is preferable that the laminated body further has a stepped portion, and at least a part of the stepped portion is covered with a folded extending portion. When the laminated body has a step on the surface where the region other than the folded and extended portion of the extended cut body is not laminated, the surface of each step becomes one surface 117 of the laminated body.

With such a configuration, the stepped portion is deformed according to the shape of the mold cavity, so that the thickness in each region of the laminated body can be brought close to the thickness of each region of the desired molded product, and compression can be performed. Depending on the pressurization during molding, the entire laminate can be pressed evenly. As a result, extensibility can be exhibited not only in the fiber orthogonal direction of the unidirectional prepreg but also in the fiber direction, and the laminate can be made to follow the desired shape of the molded product with a small amount of flow.

The stepped portion is preferably at least two steps or more, and more preferably four steps or more, from the viewpoint of evenly pressurizing the entire laminated body, although it depends on the shape of the molded product.

Further, in the preform of the present invention, it is preferable that the angle 300 formed by the fiber direction of the folded extending portion and the extending direction of the folded extending portion is 75 degrees or more and 90 degrees or less in absolute value. The angle referred to here means an acute angle (that is, less than 90 degrees) out of an obtuse angle and an acute angle formed by two straight lines, and when the two straight lines form a right angle, it means 90 degrees.

With such a configuration, the portion corresponding to the folded and extended portion of the preform becomes a burr in the fiber direction of 75 degrees or more and 90 degrees or less in absolute value by compression molding. In addition to the above-mentioned effect of having a single fiber direction of the burr, the anisotropy that the strength in the fiber orthogonal direction is smaller than that in the fiber direction reduces the tool resistance during post-machining. Further, since the one-way prepreg used in the present invention is a notched prepreg, the possibility that burrs will get caught in the surrounding product part and damage the end portion of the molded product at the time of deburring is reduced.

Further, with such a configuration, it is possible to suppress the disorder of the alignment of the fibers of the laminated body due to the invasion of the fibers of the folded extending portion into the stepped portion.

In the preform of the present invention, it is preferable that the extended cutting body is further arranged on the other surface of the laminated body. Here, the other surface of the laminated body means a surface on which regions other than the folded and extended portion of the extended cutting body are laminated. With such a configuration, it becomes possible to cover the end portion of the laminated body with one extended cutting body.

The laminate used in the present invention may also have a step on the other surface. With such a configuration, since the step on the other surface is covered with the extended cutting body laminated on the other surface, it is possible to obtain a molded product having a smooth and good design surface.

The laminate used in the present invention may be bent out of the plane or shaped into a three-dimensional shape according to the shape of the mold cavity. At this time, since the laminated thickness direction 1000 changes depending on the position of the laminated body, the laminated thickness direction of the end portion of the laminated body may differ depending on the position.

In the preform of the present invention, as shown in FIG. 6, a cover cut body having a fiber direction equal to the fiber direction of the folded extending portion is further placed on the surface of the folded extending portion or between the folded extending portion and the laminated body. It is preferable to be arranged in. The fiber direction of the folded-back extending portion as used herein refers to the fiber direction after the folded-back extending portion is folded back and preformed.

With such a configuration, even if the preform flows out of the mold cavity due to compression molding, the same direction exists in a region closer to the parting line of the mold cavity than the end of the laminate. It is more preferable for the above-mentioned reasons because it has more fibers. From the viewpoint of increasing the number of fibers in the same direction, the cover cutting portion may be arranged on the surface of the folded extending portion or between the folded extending portion and the laminate, but the design required for the molded product. It may be changed as appropriate depending on the properties and the state of occurrence of burrs during molding.

The cover cut body used in the present invention can be arranged so as to continuously cover one surface of the laminated body. With such a configuration, the surface of the molded product is covered with a single layer in the fiber direction, so that the molded product has high mechanical properties in the fiber direction due to its mechanical anisotropy and is excellent in designability. A molded product can be obtained.

The cover cut body used in the present invention can be arranged so as to discontinuously cover one surface of the laminated body. When discontinuously arranged, for example, it can be arranged so as to cover the stepped portion on one surface of the laminated body. With such a configuration, the fibers of the cover cut body invade the step, and the surface of the laminated body has a smooth and good design while suppressing the disorder of the alignment of the fibers and maintaining good mechanical properties. Molded products can be obtained.

In the preform of the present invention, as shown in FIG. 7, a cover cut body having a fiber direction equal to the fiber direction of the folded extending portion is further placed on the surface of the folded extending portion or between the folded extending portion and the laminated body. It is preferable that the layers are arranged over a region covering one surface and a region covering the laminated thickness direction of the laminated body. The fiber direction of the folded-back extending portion as used herein refers to the fiber direction after the folded-back extending portion is folded back and preformed.

With such a configuration, even if the preform flows out of the mold cavity due to compression molding, the same direction exists in a region closer to the parting line of the mold cavity than the end of the laminate. It is more preferable for the above-mentioned reasons because it has more fibers. Further, during compression molding, a region other than the folded extending portion and the folded extending portion of the extended cutting body is pressed by the mold cavity to give resistance to the end portion of the laminate, and the end portion of the laminate is moved out of the mold cavity. The outflow can be suppressed.

From the viewpoint of increasing the number of fibers in the same direction, the cover cutting portion may be arranged on the surface of the folded extending portion or between the folded extending portion and the laminate, but the design required for the molded product. It may be changed as appropriate depending on the properties and the state of occurrence of burrs during molding.

The cover cut body used in the present invention can be arranged so as to continuously cover one surface of the laminated body. With such a configuration, the surface of the molded product is covered with a single layer in the fiber direction, so that the molded product has high mechanical properties in the fiber direction due to its mechanical anisotropy and is excellent in designability. A molded product can be obtained.

The cover cut body used in the present invention can be arranged so as to discontinuously cover one surface of the laminated body. When discontinuously arranged, for example, it can be arranged so as to cover the stepped portion on one surface of the laminated body. With such a configuration, the fibers of the cover cut body invade the step, and the surface of the laminated body has a smooth and good design while suppressing the disorder of the alignment of the fibers and maintaining good mechanical properties. Molded products can be obtained.

[Production method]
Subsequently, the method for producing the preform of the present invention will be described, but the production method is not limited thereto.

The method for producing the preform of the present invention shown in FIG. 2C will be described.

First, the cutting process is carried out. The prepreg cutting bodies 111, 112, 113 and the extended cutting body 120 are obtained by the method of cutting the sheet-shaped cut prepreg shown in FIG. 1 into a predetermined shape. Alternatively, the prepreg cut bodies 111, 112, 113 and the extended cut body 120 may be obtained by arranging the cut tape-shaped cut prepregs in a predetermined shape. When the release paper or release film is attached to one side or both sides of the cut prepreg, which is the material, the release paper or release film on one side of the prepreg cut body and the extended cut body is not peeled off from the viewpoint of handleability. It is preferable to leave it. It is preferable that the surface of the extended cutting body that leaves the release paper or the release film without peeling off is a surface that does not come into contact with the laminated body in the laminating step described later.
Examples of the cutting method in the cutting process include a method using an automatic cutting machine and a method of manually cutting using a cutter or scissors. In addition, as a method of arrangement in the cutting process,
Examples include a method using an automatic tape layup machine and an automatic laminating machine, and a method of manually arranging tapes cut to a predetermined length to form a predetermined shape.

Next, a laminating step is carried out. Here, the prepreg cut body and the extended cut body are laminated in a state where the folded and extended portion is not folded back, but it may be laminated in a laminated structure that finally exhibits the desired mechanical properties, and each prepreg cut body and the extended cut body may be laminated. The work order of laminating the extended cut pieces is not important. Since the surface of the cut prepreg has tackiness (adhesiveness) at room temperature or a temperature lower than the molding temperature, it is possible to obtain an integrated laminated body by laminating and pressing each prepreg sheet. When laminating, the above-mentioned release paper or release film is peeled off and laminated, but from the viewpoint of handleability, the release paper or release film on the surface of the extended cutting body that does not come into contact with the laminate is not peeled off. It is preferable to leave it. After laminating the laminated body in advance, it may be laminated on the extended cutting body. The prepreg cut body and the extended cut body may be laminated in a plane as shown in FIG. 2 (b), or when the molded product has a three-dimensional shape, the prepreg cut body and the extended cut body are three-dimensionally laminated according to the shape. You may.

Examples of the laminating method in the laminating step include a method using a laminating automatic machine and a method of manually laminating. In the case of manually laminating, since the laminated body is laminated at a predetermined position on the extended cutting body, it is efficient and preferable to laminate while aligning with a paper pattern or a ruler.

As a subsequent step, a turn-back step is carried out. Here, the folded-back extending portion 121 is folded back along the folded-back line 124 shown in FIG. 2 (b), and the outer peripheral end portion of the laminated body is covered with the folded-back extending portion over the entire thickness of the laminated body, so that FIG. 2 (c) shows. Produce the preform shown.

As a folding method in the folding step, a method of manually folding the folded extending portion at the position of the folding line 124 is exemplified. At that time, even if it is folded back by eye measurement, there is no big effect because the material flows when the preform is press-molded. You can get the preform of. Further, it is preferable to bend the jig corresponding to the shape of the folding line 124 while pressing it against the extending cutting body so that the shape of the outer peripheral end portion is less likely to vary.

In addition, if the release paper or release film on the surface of the extended cut body is folded back with the release paper or release film attached, and the release paper or release film is peeled off after the shape is fixed, the tack folded back can be folded back while maintaining the shape of the extended part. preferable. On the other hand, if the release paper or the release film on the surface of the extended cutting body is peeled off and then folded back, the folding resistance and the in-plane deformation resistance are reduced, so that it is easy to fold back while following the shape, which is preferable. In particular, this method is preferable when the folding line 124 is a curved line or when the laminated body described later has a stepped portion.

The preform of the present invention produced as described above can be processed by press molding using, for example, a mold having a cavity shape of a molded product, and has excellent mechanical properties at the end and excellent deburring property. A molded product can be obtained.

Next, at least a part of the outer peripheral end portion of the laminate illustrated in FIG. 4B is covered over the entire thickness direction of the laminate, and a part of one surface of the laminate is covered. The method for producing the preform of the present invention will be described.

After performing the cutting step and the laminating step by the same method as described above, the folding step is carried out. The folded-back extending portion is folded back along the folding line 124 by the same method as described above to cover the outer peripheral end portion 115 of the laminated body over the entire thickness direction of the laminated body, and then the remaining folded-back extended portion is applied along the surface of the laminated body. , The tip 125 of the folded-back extending portion is laminated so as to be located on one surface 117 of the laminated body.

Next, the manufacturing process of the preform having the stepped portion exemplified in FIG. 8C will be described.

First, a cutting step is carried out in the same manner as described above to obtain prepreg cutting bodies 111, 112, 113 and extended cutting bodies 120 having different shapes as shown in FIG. 8 (a).

Next, the laminating step is carried out by the same method as described above.

Further, a turn-back process is carried out. By the same method as described above, the folded-back extending portion is folded back along the folded-back line 124 to cover the outer peripheral end portion 115 of the laminated body over the entire laminated thickness direction. Subsequently, the remaining folded-back extending portion may be laminated along the surface of the stepped portion of the laminated body, or may be floated from the stepped portion and attached. The method of laminating along the surface of the stepped portion is preferable because no gap is generated between the folded-back extending portion and the stepped portion of the laminated body, so that air bubbles are less likely to be generated inside the molded product. On the other hand, the method of floating and pasting from the stepped portion does not require time for pasting the folded-back extending portion, and even if the length of the folded-back extending portion is short, the stepped portion can be covered, so less work is required. This is a preferable form in which a preform can be efficiently produced in time.

Further, the relationship between the fiber direction of the folded-extended portion and the angle formed by the extended direction of the folded extended portion and the method of manufacturing the preform will be described.

In the folding process, if the angle between the fiber direction of the folded extending part and the extending direction of the folded extending part is 75 degrees or more and 90 degrees or less in absolute value, the resistance of folding is small, so the folding is folded back at room temperature and extended. It is preferable that the shape can be fixed by pressing the portion. On the other hand, when the angle formed by the fiber direction of the folded and extended portion and the extended direction of the folded and extended portion is less than 75 degrees in absolute value, especially when it is 0 degrees, the resistance of the folded back is large and the extended cutting body is formed. It may try to return to the original planar shape. In such a case, by heating to a temperature lower than the molding temperature in a dryer, an electric heater, or an oven and then folding back, it is possible to increase the tackiness of the cut prepreg surface while reducing the folding resistance. , It becomes easy to fix the shape.

Further, the manufacturing process of the preform having the cover cut body 130 illustrated in FIGS. 6 (b) and 6 (c) will be described.

In the cutting process, the cover cutting body 130 is manufactured by the same method as the prepreg cutting body and the extending cutting body.

As illustrated in FIG. 6B, when the cover cutting body 130 is arranged between the folded extending portion and the laminated body, the cover cutting body 130 corresponds to the laminated body or the extending cutting body in the laminating step. It is preferable to stack at the position. Following this, a folding step is carried out to obtain a preform having the cover cut body 130 of the present invention.

Further, as illustrated in FIG. 6 (c), when the cover cutting body 130 is arranged on the surface of the folded extending portion, a laminating step and a folding step are performed to obtain a preform that does not include the cover cutting body 130. After that, it is preferable to stack the cover cutting body 130 at the corresponding position. Thereby, a preform having the cover cut body of the present invention can be obtained.

Further, if necessary, the cover cut body 130 may be partially arranged between the folded-back extending portion and the laminated body, or may be arranged on the surface of the folded-back extending portion, or these may be used in combination.

Further, the cover cutting body 130 illustrated in FIGS. 7B and 7C is arranged over a region covering one surface of the laminated body and a region covering the laminated thickness direction of the laminated body. The remodeling manufacturing process will be described.

As illustrated in FIG. 7B, when the cover cutting body 130 is arranged between the folded extending portion and the laminated body, the cover cutting body 130 corresponds to the laminated body or the extending cutting body in the laminating step. It is preferable to stack at the position. When the cover cut body 130 is laminated particularly along the stepped portion of the laminated body, the cover cut body 130 may be laminated along the surface of the stepped portion of the laminated body, or may be floated from the stepped portion and attached. The method of laminating along the surface of the stepped portion is preferable because no gap is generated between the folded-back extending portion and the stepped portion of the laminated body, so that air bubbles are less likely to be generated inside the molded product. On the other hand, the method of floating and pasting from the stepped portion does not require time for pasting the folded-back extending portion, and even if the length of the folded-back extending portion is short, the stepped portion can be covered, so less work is required. This is a preferable form in which a preform can be efficiently produced in time. Following this, a folding step is carried out to obtain a preform having the cover cut body of the present invention.

Further, as illustrated in FIG. 7 (c), when the cover cutting body 130 is arranged on the surface of the folded extending portion, a laminating step and a folding step are carried out to obtain a preform that does not include the cover cutting body. Later, it is preferable to stack the cover cutting bodies at the corresponding positions. Thereby, a preform having the cover cut body of the present invention can be obtained.

Further, if necessary, the cover cut body 130 may be partially arranged between the folded-back extending portion and the laminated body, or may be arranged on the surface of the folded-back extending portion, or these may be used in combination.

[Use]
Applications of the molded product obtained by using the preform of the present invention include, for example, electrical and electronic equipment parts, civil engineering, building material parts, automobiles, motorcycle structural parts, and aircraft parts.

Further, from the viewpoint of mechanical properties, it is preferably used for housings for electric and electronic devices, civil engineering, panels for building materials, structural parts for automobiles, and parts for aircraft.

100: Preform 105: Preform end 1000: Laminated thickness direction 110: Laminated body 111, 112, 113: Prepreg cut body 115: Outer peripheral end of the laminated body 116: The other surface of the laminated body 117: One of the laminated bodies Surface 120: Extended cutting body 121: Extended portion 1210: Extended direction 124: Folded line 125: Extended portion end 130: Cover cut body 150: One-way prepreg 152: Reinforcing fiber 153: Thermosetting resin 154: Notch 1520: Fiber direction 300: Angle formed by the fiber direction of the folded extension portion and the extending direction of the folded extension portion

Claims (7)

A preform in which two or more prepreg cut bodies composed of a unidirectional prepreg having a predetermined shape containing reinforcing fibers and a thermosetting resin are laminated, and the unidirectional prepreg is a continuous fiber and the reinforcing fibers are continuous fibers. , A cut prepreg having a plurality of cuts across the continuous fiber, the preform covers a laminate having one or more prepreg cut bodies and an outer peripheral end portion of the laminate over the entire thickness direction of the laminate. It is characterized in that it has one or more extended cutting bodies made of the one-way prepreg having at least a part of the folded extending portion to be covered with the laminated body, and the thickness of the laminated body is equal to or larger than the thickness of the extended cutting body. Preform. The device according to claim 1, wherein at least a part of the outer peripheral end portion of the laminated body is covered over the entire area in the thickness direction of the laminated body, and a part of one surface of the laminated body is covered. Remodeling. The preform according to claim 2, wherein the laminated body has a stepped portion, and at least a part of the stepped portion is covered with the folded-back extending portion. The invention according to any one of claims 1 to 3, wherein the angle formed by the fiber direction of the folded-back extending portion and the extending direction of the folded-back extending portion is 75 degrees or more and 90 degrees or less in absolute value. preform. The preform according to any one of claims 1 to 3, wherein the extended cutting body is arranged on the other surface of the laminated body. The claim is characterized in that a cover cut body having a fiber direction equal to the fiber direction of the folded extending portion is arranged on the surface of the folded extending portion or between the folded extending portion and the laminated body. The preform according to any one of 1 to 5. The cover cutting body having a fiber direction equal to the fiber direction of the folded extending portion covers the surface of the folded extending portion or between the folded extending portion and the laminated body and the region covering the one surface. The preform according to any one of claims 2 to 5, wherein the preform is arranged over a region covering the laminated thickness direction of the laminated body.

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