JP2007238885A - Prepreg material and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a prepreg material being free from the lifting or peeling from a release paper of the prepreg and having excellent shape retention stability. <P>SOLUTION: The prepreg material comprises a prepreg which includes a reinforcing fiber and a matrix resin and is carried by a release paper on one or both sides. The release paper has an initial elastic deformation load in the longitudinal direction of ≥90 N/15 mm. A method of manufacturing the prepreg material is also provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a prepreg material obtained by supporting a prepreg, which is an intermediate base material used for molding a fiber-reinforced composite material, on a release paper and a method for producing the prepreg material, and more specifically, floating of a prepreg from a release paper, The present invention relates to a prepreg material having excellent form storage stability without peeling and a method for producing the same.

  Fiber reinforced composite materials are widely used from sports applications to aircraft applications because of their light weight and excellent strength and elastic modulus. The prepreg, which is an intermediate substrate used for molding the fiber-reinforced composite material, is obtained by impregnating a reinforcing fiber with a resin composition. This prepreg is adjusted to a desired shape and then molded into a predetermined shape by heat molding to form a fiber-reinforced composite material. In order to maintain, store or transport the prepreg, a release paper is placed on one side, a protective film such as polyethylene film is placed on the other side, and rolls or sheets with a desired size are laminated in multiple layers. It is normal. In this way, the prepreg material having one side supported by the release paper is in a state where tension is applied during the manufacturing process, and the release paper is stretched, but when released from this tension, the elongation is restored. The prepreg that is pasted cannot follow the change because it tries to float, and the prepreg and the release paper are partially peeled off, and the prepreg is lifted from the release paper so that the diameter exceeds 3 mm. To do. When a prepreg with such a squeak is generated, wrinkles and voids are generated in the molded product, resulting in problems such as poor appearance quality of the molded product and further reduced strength.

The change in the size of the release paper that causes such unevenness is due to large strain, stress, and tension applied to the release paper during the prepreg manufacturing process, and in order to reduce the elongation of the release paper, There is a proposal to reduce the blur by using a release paper having an elastic elongation rate in the direction at 4 kg / 15 mm load (39.2 N / 15 mm) of 0.60% or less (see Patent Document 1). However, even if the technique proposed in Patent Document 1 is used, the expansion and contraction due to the tension applied to the release paper during the prepreg manufacturing process cannot be sufficiently reduced, and a sufficient effect for suppressing unevenness cannot be obtained. is the current situation.
JP 2000-61940 A

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a prepreg material with little unevenness.

In order to achieve the above object, the present invention has one of the following configurations.
(1) A prepreg material in which a prepreg containing reinforcing fibers and a matrix resin is supported on a release paper on at least one surface thereof, and the release paper has a longitudinal initial elastic deformation load of 90 N / 15 mm or more. A prepreg material characterized by
(2) The prepreg material according to (1) above, wherein the peel resistance between the prepreg and the release paper is 0.1 to 2.5 N / 25 mm.
(3) The prepreg material according to the above (1) or (2), wherein the release paper has a lateral initial elastic deformation load of 55 N / 15 mm or more.
(4) The prepreg material according to any one of (1) to (3), wherein the reinforcing fibers are carbon fibers.
(5) The prepreg material according to any one of (1) to (4), wherein the matrix resin is a resin composition containing an epoxy resin.
(6) The prepreg material according to any one of (1) to (5), wherein the reinforcing fibers are reinforcing fiber bundles arranged in one direction.
(7) The prepreg according to any one of (1) to (6), wherein the reinforcing fiber has a tensile elastic modulus of 300 GPa or more, and the prepreg has a reinforcing fiber basis weight of less than 100 g / m ^2. Wood.
(8) The prepreg material according to any one of (1) to (7), wherein the prepreg has a reinforcing fiber weight content of 65% by weight or more.
(9) A method for producing a prepreg material in which a reinforcing fiber is formed into a sheet, and the sheet is impregnated with a resin by pressing a release paper formed by applying a matrix resin from at least one side or both sides of the sheet, The release paper has a longitudinal initial elastic deformation load of 90 N / 15 mm or more, and a method for producing a prepreg material.
(10) The prepreg material according to the above (9), wherein when the sheet is impregnated with the resin, the pressure between the rolls is pressed at a linear pressure of 9.8 to 19.6 kN / 1000 mm width between at least a pair of rolls. Manufacturing method.

  ADVANTAGE OF THE INVENTION According to this invention, the problem of the float from the release paper of a prepreg and a peeling can be solved, and the prepreg material which is excellent in form preservation stability can be provided.

  The prepreg material of the present invention comprises a prepreg containing reinforcing fibers and a matrix resin supported on a release paper on at least one surface. The release paper has a longitudinal initial elastic deformation load of 90 N / 15 mm or more. Here, the longitudinal direction of the release paper is a process direction when a continuous prepreg material is manufactured. In general, the prepreg material carried on the release paper is stretched in the vertical direction due to the tension applied in the process direction during the manufacturing process, but when the release paper is released from this tension, the elongation tends to return. For this reason, the attached prepreg cannot follow the change, resulting in unevenness. In order to suppress this unevenness, it is preferable to use a sheet having a small longitudinal expansion / contraction of the release paper due to the process tension, that is, a higher initial elastic deformation load in the longitudinal direction of the release paper than that of the conventional release paper. The longitudinal initial elastic deformation load of the release paper is preferably 100 N / 15 mm to 200 N / 15 mm, more preferably 100 N / 15 mm to 150 N / 15 mm, and still more preferably 110 N / 15 mm to 130 N / 15 mm. Use paper pattern. If a release paper whose longitudinal initial elastic deformation load is too small is used, the elongation of the release paper due to the tension applied during the process becomes too large, and the prepreg cannot follow the change, resulting in unevenness. On the other hand, if the initial elastic deformation load in the longitudinal direction is too large, the effect of suppressing blurring will be manifested, but if it is too large, the release paper will hardly expand or contract, so the winding form when the prepreg and release paper are wound in a roll shape Since the occurrence of defects and the deterioration of handleability may occur, the longitudinal initial elastic deformation load is preferably 200 N / 15 mm or less.

  Here, the longitudinal initial elastic deformation load of the release paper in the present invention can be measured as follows. The release paper pretreated according to JIS P8111 is cut into strips having a width of 15 mm and a length of 200 mm so that the longitudinal direction is the length direction, and a test piece is obtained. Tighten one end of the test piece firmly to the center of the upper grip of the tensile strength measuring instrument, and then fix and tighten the test piece to the center of the lower grip so that it does not loosen. When this is pulled at a pulling speed of 100 mm / min, the release paper is determined as a load at the time of 1% elongation relative to the initial length. Usually, the release paper is supplied in a roll shape, and it is preferable to measure the initial elastic deformation load in the longitudinal direction using the roll release paper. In Examples to be described later, a Tensilon universal testing machine was used as a tensile strength measuring device.

  The release paper used in the present invention preferably has not only the longitudinal initial elastic deformation load in the specific range but also the lateral initial elastic deformation load of 55 N / 15 mm or more. It is preferable to use a release paper having a lateral initial elastic deformation load within a range of preferably 60 N / 15 mm to 100 N / 15 mm, more preferably 60 N / 15 mm to 80 N / 15 mm. Here, the horizontal direction of the release paper indicates the width direction of the continuous prepreg product. If release paper with too low lateral initial elastic deformation load is used, the reinforcing fiber sheet and release paper formed by applying matrix resin from at least one side or both sides of the sheet are passed through at least a pair of rolls and pressed. When manufacturing a prepreg material by impregnating the resin, the release paper is rolled in the horizontal direction and tries to return to the original state after passing through the roll. It may end up. In addition, even if the initial elastic deformation load in the lateral direction is too large, it does not affect the degree of unevenness, but if it is too large, the release paper is too elastic, so the release paper is rolled up with the prepreg. It may be difficult.

  Here, the initial elastic deformation load in the horizontal direction is the same as the initial initial elastic deformation load obtained by cutting the release paper into strips having a width of 15 mm and a length of 200 mm so that the horizontal direction is the length direction. The method may be measured.

Release paper suitably used in the prepreg of the present invention, for example, wood fibers, sizing agents, eye on at least one surface of the manufactured from aluminum sulfate, the basis weight 50g / m ² ~150g / m ² of substrate It is obtained by providing a stop layer and then applying a release agent to the surface layer of the seal layer. In particular, by using a base material having a specific basis weight, a release paper having an initial elastic deformation load in the specific range described above can be obtained. Here, examples of the base material include high-quality paper, craft paper, glassine paper, parchment paper, supercalendered kraft paper, and the like. In particular, glassine paper, parchment paper, or supercalendered kraft paper is preferably used. The sealing layer is formed by applying clay having good heat resistance and water resistance together with a binder, coating polyvinyl alcohol, carboxymethyl cellulose, starch or the like, or coating them together. Examples of the coating apparatus for providing the sealing layer include an air doctor coater, a size press coater, a gate roll coater, a knife coater, and a reverse coater. The coating amount of the sealing layer is usually 15 to 30 g / m ² per side. If the coating amount of the sealing layer is too small, it becomes difficult to obtain a sufficient barrier property for coating the release material. Moreover, it is preferable to apply the sealing layer on both surfaces of the substrate. The release agent is not particularly limited as long as it has a release effect. For example, a known release agent such as a silicone resin or a long-chain alkyl resin having a functional group at the molecular end or side chain may be used. It is preferable to use a silicone resin because it is excellent in solvent resistance and heat resistance and enables fine control of peeling performance. For example, a gravure coater, a rod coater, an air doctor coater, or the like can be used as the release agent coating apparatus. What is necessary is just to adjust suitably the coating amount of a release agent according to peeling resistance with the prepreg mentioned later, Preferably it is 0.1-20 g / m < ² > per single side | surface. If the coating amount of the release agent is too small, it may cause a peeling failure, and if it is too much, it not only becomes uneconomical but also may cause a curing failure of the release agent.

  In the prepreg material of the present invention, the peel resistance between the prepreg and the release paper is preferably 0.1 to 2.5 N / 25 mm, more preferably 0.3 to 2.5 N / 25 mm. 5 to 2.5 N / 25 mm is more preferable, and 0.7 to 2.5 N / 25 mm is particularly preferable. Moreover, what is necessary is just to adjust the release agent coating amount of a release paper so that it may become these peeling resistance. If the peeling resistance between the prepreg and the release paper is too small, the adhesion between the prepreg and the release paper is weak, so that the prepreg material is likely to be blurred when the size of the release paper changes. When the dimensions of the paper pattern change, the prepreg tends to float or rip off. On the other hand, if the peeling resistance is too large, the adhesion between the prepreg and the release paper is too strong, making it difficult to peel off the prepreg and the release paper during molding, which may reduce the efficiency of the molding operation.

  Here, the peel strength between the prepreg and the release paper is measured as follows. That is, the prepreg material is cut into a strip shape having a width of 25 mm and a length of 300 mm with the release fiber as the release paper and the direction of the reinforcing fiber as the length direction. Next, as shown in FIG. 1, the test piece 1 was covered with a double-sided adhesive tape (for example, a double-sided tape T4000 manufactured by Sony Chemical Co., Ltd., having a width of 50 mm) having a size that can cover the entire test piece. The release paper is pasted on the stainless steel support 2. Next, as shown in FIG. 2, the support 2 is attached to the lower chuck 4 (fixed) of the tensile tester, and the peeled end of the release paper 1b that has been peeled off about 10 mm from the prepreg 1a is attached to the clip 5 and the metal. It is attached to the upper chuck 7 (movable) via the wire 6 and pulled from the prepreg 1a by pulling the release paper 1b at a pulling speed of 100 mm / min in an atmosphere of 23 ° C. and 50% RH. To record. Then, from the chart until peeling is completed, excluding 1 minute at the beginning of peeling and 1 minute at the end of peeling, the top of the load peak is read from the highest five points and the bottom of the load valley is read from the lower five points Then, a simple average value of the loads at these 10 points is obtained and defined as the peel strength. As the tensile tester, an appropriate material tester of a type in which the load measurement error does not exceed ± 1% and the crosshead moving speed can be kept constant is used. For example, a universal tensile testing machine such as Tensilon UTM-4L manufactured by Toyo Seiki Co., Ltd. can be used.

  In the present invention, the matrix resin may contain either a thermoplastic resin or a thermosetting resin, but is preferably a thermosetting resin, and particularly preferably a thermosetting epoxy resin. A thermosetting epoxy resin is a resin composition containing an epoxy resin. Such a resin composition usually contains a curing agent and, if necessary, a curing aid. As the epoxy resin, for example, bisphenol A type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, alicyclic epoxy resin, urethane-modified epoxy resin, brominated bisphenol A type epoxy resin and the like can be used. These epoxy resins can be used singly or in combination of two or more kinds, and can be selected and used conveniently according to the properties required for the prepreg such as tackiness from liquid to solid. it can. Further, it is preferable to attach an appropriate curing agent and curing aid depending on the type of resin and the required characteristics. Furthermore, an appropriate thermoplastic resin or inorganic particles may be added in order to control the peeling resistance between the release paper and the prepreg material and to improve the handleability.

  Examples of the reinforcing fiber used in the present invention include carbon fiber, glass fiber, and aramid fiber, and it is desirable to use carbon fiber exhibiting particularly excellent mechanical properties when formed into a molded body. As such carbon fibers, polyacrylonitrile-based or pitch-based carbon fibers can be used.

  The reinforcing fiber used in the present invention is usually formed in a sheet shape. The sheet is not particularly limited as long as it is in a sheet form, and may be a sheet in which a plurality of reinforcing fiber bundles are aligned in one direction. A woven fabric, a knitted fabric, a nonwoven fabric, other fabrics, or a combination thereof. A thing etc. can also be selected and used suitably.

  In the present invention, when a reinforcing fiber having a high tensile elastic modulus of 300 GPa or more, preferably 300 to 600 GPa, more preferably 350 to 600 GPa, further preferably 450 to 600 GPa, most preferably 550 to 600 GPa is used. It is particularly effective. Here, the tensile elastic modulus of the carbon fiber bundle is determined in accordance with a method defined in JIS R-7601. In general, the higher the elastic modulus of the reinforcing fiber, the more difficult it is to follow the change in the expansion and contraction of the release paper, and the occurrence of blurring tends to occur, but if a release paper with a small amount of expansion and contraction is used like the release paper of the present invention, Further, it becomes difficult to generate unevenness even for a high elastic modulus reinforcing fiber.

Furthermore, the present invention is also effective when producing a low-weight prepreg having a reinforcing fiber basis weight of less than 100 g / m ^{2 in the} prepreg. In general, the production of a low-weight prepreg having a basis weight of reinforcing fiber in the prepreg of less than 100 g / m ² is performed by expanding the reinforcing fiber with a high roll pressure of 9.8 kN / 1000 mm or more in the step of impregnating the reinforcing fiber with a matrix resin. Due to the sheet shape, the release paper is rolled in the width direction and is likely to generate unevenness. However, if a release paper with a small amount of expansion and contraction is used like the release paper of the present invention, the release paper has a high elastic modulus. Is less likely to cause unevenness.

  Further, in the present invention, the reinforcing fiber may be contained in the prepreg in an amount of 65 to 90% by weight, more preferably 70 to 85% by weight, and further preferably 75 to 85% by weight, based on the weight of the prepreg. When the content of the reinforcing fiber is too large, the peeling resistance between the prepreg and the release paper tends to fall below the lower limit described above, and the prepreg material tends to float.

  Next, an example of a method for producing the prepreg material of the present invention will be described. That is, in the method for producing a prepreg material of the present invention, the reinforcing fiber is formed as a sheet as described above, and the release paper formed by applying the matrix resin as described above is pressed from at least one side or both sides of the sheet. Thus, the sheet is impregnated with resin. Here, the specific release paper described above is used as the release paper.

  FIG. 3 is a schematic view showing an example of a prepreg material manufacturing apparatus that can suitably carry out the method of the present invention.

  For example, when manufacturing using a sheet in which a plurality of reinforcing fiber bundles are aligned in one direction, in FIG. 3, the aligning rolls 10 and 11 that freely rotate the reinforcing fiber bundles 9 pulled out from a large number of packages 8. After that, they are led to the comb 12 and are arranged in parallel and in a sheet form to obtain a reinforcing fiber sheet 20. Next, the lower side coated with a matrix resin such as a B-stage thermosetting resin supplied to the reinforcing fiber sheet 20 via the release roll 14 and also supplied via the introduction roll 15. The release paper 16 is superposed so that the resin-coated surface faces the reinforcing fiber sheet 20, the superposed body is heated by the heater 17, and the viscosity of the matrix resin is once lowered. By heating and pressurizing as described above, the reinforcing fiber bundle 20 is expanded and the matrix resin on the release paper 16 is transferred and impregnated into the reinforcing fiber sheet 20. That is, the reinforcing fiber sheet becomes a unidirectional prepreg. After the matrix resin is transferred and impregnated, the upper release paper 14 is peeled off, and the unidirectional prepreg material 21 is rolled up together with the lower release paper 16 to form a roll body 22. Thus, a unidirectional prepreg material in which reinforcing fibers extend in the length direction of the strip-shaped release paper is obtained.

  Here, the above-mentioned specific release paper is used as the release paper carrying the prepreg in the prepreg material, that is, the lower release paper 16 in FIG. In particular, when a release paper whose longitudinal initial elastic deformation load is too small is used, the release paper stretched by the tension applied during the manufacturing process of the prepreg material tends to return to the original state when released from the tension. The attached prepreg cannot follow the change, and the prepreg and the release paper are partly peeled off, and the prepreg is lifted or loosened.

  Further, a release paper in which a resin is applied to both the upper release paper 14 and the lower release paper 16 may be used, or a release paper in which a resin composition is applied to the upper release paper 14 is used. Thus, it is possible to use a release paper to which the resin composition is not applied as the lower release paper 16. Of course, a mechanism may be used in which the upper release paper is rolled up together with the prepreg in a roll shape, and the lower release paper is peeled and collected. In addition, a protective film such as a polyethylene film is attached so as to cover the prepreg side before winding up, so that the prepreg can be protected from moisture absorption or damage due to external force.

  Here, the pressure for impregnating the sheet with the resin by the impregnation rolls 18 and 19 is preferably set to a linear pressure of 9.8 to 19.6 kN / 1000 mm width. By setting the linear pressure within this range, the reinforcing fibers can be pushed out and the reinforcing fiber sheet can be impregnated with the matrix resin, and a prepreg product with good quality can be obtained. If the linear pressure is too high, the resin will protrude beyond the width of the prepreg product, so 19.6 kN / 1000 mm width or less is sufficient.

  The temperature at which the sheet is impregnated with the resin, so-called impregnation temperature is not particularly limited and is selected according to the type of the resin. For example, when a resin composition containing an epoxy resin is used as the matrix resin, etc. Is preferably 70 ° C. or higher, more preferably 80 ° C. to 140 ° C., and still more preferably 90 to 130 ° C. If the impregnation temperature is too low, the resin is not sufficiently spread between the individual fibers of the reinforcing fiber bundle, and voids are generated in the fiber reinforced composite material obtained by molding the prepreg, causing a decrease in mechanical strength. On the other hand, if the impregnation temperature is too high, problems such as a shortened usable period of the prepreg may occur.

Hereinafter, the present invention will be described more specifically with reference to examples.
[Example 1]
Using the prepreg material manufacturing apparatus shown in FIG. 3, 136 carbon fiber bundles 9 are pulled out from the package 8 and are arranged in parallel and in a sheet form with a comb 12 to form a reinforcing fiber sheet 20, and then the reinforcing fiber sheet 20. The release paper 14 and the release paper 16 coated with the epoxy resin composition so that the basis weight is 11 g / m ² are overlapped so that the epoxy resin application surface faces the reinforcing fiber sheet 20 side. While heating to 110 ° C. with a heater 17, the impregnation rolls 18 and 19 are pressed with a linear pressure of 14.7 kN / 1000 mm width to spread the reinforcing fiber bundle 20 and to the reinforcing fiber sheet 20 of the epoxy resin composition on the release paper 16. The unidirectional prepreg material 21 in which the prepreg was supported on the release paper 16 was obtained. This unidirectional prepreg material had a width of 1000 mm, a carbon fiber basis weight of 25 g / m ² , and a carbon fiber content in the prepreg of 70% by weight.

  As the reinforcing fiber, a carbon fiber bundle having a tensile modulus of elasticity: 378 GPa, a fineness: 0.186 g / m, and the number of single fibers: 4500 is used, and as the matrix resin, liquid and solid epoxy resins are respectively used 4: An epoxy resin composition mixed at a ratio of 5 and added with a curing agent was used. As the release paper 16, the following was used.

Base material: fine paper (basis weight 90 g / m ² )
Sealing layer: clay binder (double-sided coating, 15 g / m ² per side)
Release material: Silicone resin (double-sided coating, 1.0 g / m ² per side)
Initial elastic deformation load: 103N / 15mm in the vertical direction, 60N / 15mm in the horizontal direction
With respect to the obtained prepreg material, the peel resistance between the prepreg and the release paper was measured and found to be 0.75 N / 25 mm. Further, the obtained prepreg material is cut into a sheet having a length of 1000 mm × 1000 mm, and left for 1 hour in an environment of 24 ° C. and 50% RH, and then the sheet surface is observed to separate a prepreg material having a major axis of 3 mm or more. When the number of bumps rising from the pattern paper was measured, no bumps were observed on the surface of the prepreg material, and there was no problem in handling.
[Example 2]
The same as Example 1 except that the number of carbon fiber bundles used was changed to 103, the release paper 16 was changed to the following, and the basis weight of the epoxy resin composition applied thereto was changed to 15 g / m ^2. Thus, a unidirectional prepreg material 21 was obtained.

Base material: Fine paper (basis weight 85 g / m ² )
Sealing layer: clay binder (double-sided coating, 5 g / m ² per side)
Release material: Silicone resin (double-sided coating, 1.2 g / m ² per side)
Initial elastic deformation load: longitudinal direction 106N / 15mm, lateral direction 51N / 15mm
This unidirectional prepreg material had a width of 1000 mm, a carbon fiber basis weight of 25 g / m ² , and a carbon fiber content in the prepreg of 63% by weight. With respect to the obtained prepreg material, the peel resistance between the prepreg and the release paper was measured and found to be 0.08 N / 25 mm. Further, when the obtained prepreg material was cut into a sheet having a length of 1000 mm × 1000 mm and observed, the prepreg material had little unevenness of 3 pieces / 1000 mm ² and had no problem in handling.
[Example 3]
The number of carbon fiber bundles used was changed to 103, the release paper 16 was changed to the following, the basis weight of the epoxy resin composition applied to this was changed to 15 g / m ² , and the lines in the impregnating rolls 18 and 19 were changed. A unidirectional prepreg material 21 was obtained in the same manner as in Example 1 except that the pressure was changed to 20.6 kN / 1000 mm width.

Base material: Fine paper (basis weight 85 g / m ² )
Sealing layer: clay binder (double-sided coating, 10 g / m ² per side)
Release material: Silicone resin (double-sided coating, 1.5 g / m ² per side)
Initial elastic deformation load: 103N / 15mm in the vertical direction, 60N / 15mm in the horizontal direction
This unidirectional prepreg material had a width of 1000 mm, a carbon fiber basis weight of 25 g / m ² , and a carbon fiber content in the prepreg of 63% by weight. With respect to the obtained prepreg material, the peel resistance between the prepreg and the release paper was measured and found to be 0.08 N / 25 mm. Moreover, when the obtained prepreg material was cut into a sheet having a length of 1000 mm × 1000 mm and observed, the prepreg material was found to have a small unevenness of 4 pieces / 1000 mm ^2, and there was no problem in handling.
[Comparative Example 1]
The same as Example 1 except that the number of carbon fiber bundles used was changed to 103, the release paper 16 was changed to the following, and the basis weight of the epoxy resin composition applied thereto was changed to 15 g / m ^2. Thus, a unidirectional prepreg material 21 was obtained.

Base material: fine paper (basis weight 48 g / m ² )
Sealing layer: clay binder (double-sided coating, 16 g / m ² per side)
Release material: Silicone resin (double-sided coating, 1.0 g / m ² per side)
Initial elastic deformation load: 80N / 15mm in the vertical direction, 52N / 15mm in the horizontal direction
This unidirectional prepreg material had a width of 1000 mm, a carbon fiber basis weight of 25 g / m ² , and a carbon fiber content in the prepreg of 63% by weight. With respect to the obtained prepreg material, the peel resistance between the prepreg and the release paper was measured and found to be 0.08 N / 25 mm. In addition, when the obtained prepreg material was cut into a sheet having a length of 1000 mm × 1000 mm and observed, the prepreg was found to be bumpy, and the prepreg had a bumpiness of 100/1000 m ² and the appearance was very unsightly. Met.
[Comparative Example 2]
The same as Example 1 except that the number of carbon fiber bundles used was changed to 103, the release paper 16 was changed to the following, and the basis weight of the epoxy resin composition applied thereto was changed to 15 g / m ^2. Thus, a unidirectional prepreg material 21 was obtained.

Base material: fine paper (basis weight 86 g / m ² )
Sealing layer: clay binder (double-sided coating, 5 g / m ² per side)
Release material: Silicone resin (double-sided coating, 1.2 g / m ² per side)
Initial elastic deformation load: longitudinal direction 88N / 15mm, lateral direction 53N / 15mm
This unidirectional prepreg material had a width of 1000 mm, a carbon fiber basis weight of 25 g / m ² , and a carbon fiber content in the prepreg of 63% by weight. The peel resistance between the prepreg and the release paper 16 was 0.75 N / 25 mm. Further, when the obtained prepreg material was cut into a sheet having a length of 1000 mm × 1000 mm and observed, the prepreg was cut off, and after 30 minutes the bokeh was 70 pieces / 1000 m ² , and the appearance was very high. It was unsightly.
[Comparative Example 3]
A unidirectional prepreg material 21 was obtained in the same manner as in Example 1 except that the number of carbon fiber bundles used was changed to 103 and the release paper 16 was changed to the following.

Base material: Fine paper (basis weight 85 g / m ² )
Sealing layer: Clay binder (Coating only on one side 16g / m ² )
Release material: Silicone resin (double-sided coating, 1.0 g / m ² per side)
Initial elastic deformation load: 87N / 15mm in the vertical direction, 58N / 15mm in the horizontal direction
This unidirectional prepreg material had a width of 1000 mm, a carbon fiber basis weight of 25 g / m ² , and a carbon fiber content in the prepreg of 70% by weight. With respect to the obtained prepreg material, the peel resistance between the prepreg and the release paper was measured and found to be 0.56 N / 25 mm. Moreover, when the obtained prepreg material was cut into a sheet having a length of 1000 mm × 1000 mm and observed, the prepreg was cut, and after 30 minutes, the bokeh was 50/1000 m ² , and the appearance was very high. It was unsightly.

  The present invention is suitable as an intermediate base material for producing fiber reinforced composite fiber materials constituting various sports applications such as fishing rods and golf shafts, fiber reinforced composite materials constituting aircraft and aerospace equipment, and other various fiber reinforced composite materials. Used for.

It is a schematic perspective view of the support tool used for the measurement of the prepreg peel strength. It is the schematic which shows a mode that the peeling strength of a prepreg is measured. It is a schematic side view which shows an example of the prepreg material manufacturing apparatus used suitably by this invention.

Explanation of symbols

1: Test piece (prepreg material)
DESCRIPTION OF SYMBOLS 1a: Unidirectional prepreg 1b: Release paper 2: Test piece support 3: Double-sided tape 4: Lower chuck 5: Clip 6: Metal wire 7: Upper chuck 8: Reinforcing fiber bundle package 9: Reinforcing fiber bundle 10: Draw roll 11: Draw roll 12: Comb 13: Introduction roll 14: Upper paper release paper 15: Introduction paper 16: Lower paper release paper 17: Heater 18: Impregnation roll 19: Impregnation roll 20: Reinforcing fiber sheet 21: One Directional prepreg material 22: Roll body of unidirectional prepreg material

Claims (10)

A prepreg material in which a prepreg containing reinforcing fibers and a matrix resin is supported on a release paper on at least one surface, wherein the release paper has a longitudinal initial elastic deformation load of 90 N / 15 mm or more. Prepreg material. The prepreg material according to claim 1, wherein the peeling resistance between the prepreg and the release paper is 0.1 to 2.5 N / 25 mm. The prepreg material according to claim 1 or 2, wherein the release paper has a lateral initial elastic deformation load of 55 N / 15 mm or more. The prepreg material according to any one of claims 1 to 3, wherein the reinforcing fibers are carbon fibers. The prepreg material according to any one of claims 1 to 4, wherein the matrix resin is a resin composition containing an epoxy resin. The prepreg material according to any one of claims 1 to 5, wherein the reinforcing fiber is a sheet in which a plurality of reinforcing fiber bundles are aligned in one direction. The reinforcing fibers, the tensile modulus is at least 300 GPa, and the prepreg, the reinforcing fibers basis weight is less than 100 g / ^{m 2,} the prepreg material according to any one of claims 1 to 6. The prepreg material according to any one of claims 1 to 7, wherein the prepreg has a reinforcing fiber weight content of 65% by weight or more. A method for producing a prepreg material in which a reinforcing fiber is formed into a sheet, and the sheet is impregnated with resin by pressing a release paper formed by applying a matrix resin from at least one side or both sides of the sheet. Is a method for producing a prepreg material, wherein the initial elastic deformation load in the longitudinal direction is 90 N / 15 mm or more. The method for producing a prepreg material according to claim 9, wherein when the sheet is impregnated with the resin, the pressure between the rolls is pressurized as a linear pressure of 9.8 to 19.6 kN / 1000 mm width between at least a pair of rolls.

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