JP5029072B2 - Reinforced fiber substrate laminate and method for producing the same - Google Patents

Description

  The present invention relates to a reinforced fiber substrate laminate for producing a preform as an intermediate substrate when a reinforced fiber plastic is produced by a resin injection molding method, particularly a resin transfer molding method (hereinafter referred to as RTM method), and its production. Regarding the method.

  Composite materials using carbon fibers and the like as reinforcing fibers have been used mainly for aviation, space, and sports applications because they have excellent mechanical properties and light weight properties. A typical example of these production methods is a resin injection molding method such as the RTM method, and a large member having a complicated shape can be molded in a short time.

  In this RTM molding method, a preform made of reinforcing fibers is placed in a mold, and a liquid matrix resin is injected to impregnate the reinforcing fibers with the matrix resin. Can be obtained.

  A preform applied to a resin injection molding method such as the RTM method conventionally conforms to a final shape of a reinforcing fiber substrate laminate in which reinforcing fiber substrates in which flat reinforcing fibers are arranged are arranged one by one in the thickness direction. It was created by transporting and placing it on a shaped shaping mold. However, when a preform is produced using the reinforcing fiber base laminate, the laminated layers of the reinforcing fiber base laminate are not joined. The reinforcing fiber base laminate is misaligned during transport to the fiber, and the reinforcing fiber base slips down when placed in a mold. There was a problem that it was difficult to obtain plastic.

  Therefore, an attempt has been made to produce a reinforcing fiber base laminate in which the layers between the reinforcing fiber base laminates are bonded in advance by some means. For example, a reinforcing fiber base laminate in which laminated layers are joined by a resin material containing a thermoplastic resin has been proposed (Patent Document 1). Since the reinforcing fiber base laminate has a bonding strength in the thickness direction between the reinforcing fiber base laminate layers of a certain value or more, the reinforcing fiber base may slide down even when arranged in a three-dimensional mold. In addition, since the resin material is arranged between the reinforcing fiber base laminate layers, a highly reliable reinforcing fiber plastic such as excellent mechanical properties such as compressive strength after application of impact can be obtained. However, when the reinforcing fiber base laminate is placed along a portion having a small radius of curvature, there is a problem that wrinkles occur because sliding between the laminated layers does not occur smoothly.

  As another example, there has been proposed one in which reinforcing fibers are raised by needle punching and the reinforcing fiber base laminates are bridged together (Patent Document 2). The reinforcing fiber substrate laminate also has a problem that wrinkles are generated when it is along a portion having a small curvature radius.

On the other hand, a reinforcing fiber base laminate in which only end portions are joined with a thermoplastic resin has been proposed as a reinforcing fiber base laminate in which sliding between laminated layers smoothly occurs (Patent Document 3). When the reinforcing fiber base laminate is shaped into a three-dimensional shape, each laminated layer slides with the joint portion at the end as a base point, so that a preform without wrinkles can be produced. However, the reinforcing fiber base laminate is not joined except at the end, and the reinforcing fiber base is turned up or the orientation angle is shifted when being conveyed to a mold or when it is shaped. However, it was insufficient in that a three-dimensional shape preform was accurately and efficiently produced.
JP 2004-114586 A JP 2004-60058 A Japanese Patent Laid-Open No. 5-185539

An object of the present invention is to provide a reinforced fiber base laminate that solves such problems, has excellent handleability, can be shaped without difficulty even in a three-dimensional shape, and provides a reinforced fiber plastic having excellent mechanical properties. There is to do.

The present invention adopts the following configuration in order to solve such a problem. That is,
(1) A planar reinforcing fiber substrate laminate formed by laminating a plurality of reinforcing fiber substrates, wherein joints are distributed over the entire surface between the laminated layers of the reinforcing fiber substrates, , a glass transition temperature Tg resin containing a thermoplastic resin is 2g / m ² ~40g / m ² are attached is a 0 ° C. to 95 ° C., and the both reinforcing fiber substrates forming the laminated layers In addition to being formed by fusing, the stacked layers are formed from a high bonding region having a bonding force of 500 to 1000 N / m ² and a low bonding region in which the density of distribution of bonding portions is lower than that of the high bonding region. Reinforced fiber base laminate characterized by being made.

  (2) The reinforcing fiber substrate laminate according to (1), wherein a ratio of the highly bonded region between the laminated layers is 1 to 10%.

  (3) The reinforcing fiber base laminate according to (1) or (2), wherein the high bonding region is a region having a width of 1 to 5 cm from an end of the reinforcing fiber base laminate.

  (4) The reinforcing fiber group according to any one of (1) to (3), wherein a bonding force between the layers in the high bonding region is 1.5 to 5 times a bonding force between the layers in the low bonding region. Material laminate.

  (5) A preform having a reinforcing fiber volume fraction Vpf of 40% to 62% obtained by shaping the reinforcing fiber substrate laminate according to any one of (1) to (4).

  (6) The preform according to (5), wherein the preform is bonded to the entire surface between the reinforcing fiber base layers with a resin containing the thermoplastic resin.

  (7) Fiber reinforced plastic molding in which the reinforcing fiber volume fraction Vf obtained by injecting, impregnating and curing the matrix resin into the preform described in (5) or (6) is in the range of 35% to 72%. Goods.

(8) on at least one surface of the reinforcing fiber substrate, resin containing a thermoplastic resin having a glass transition temperature Tg of 0 ° C. to 95 ° C. ^is deposited within a range of 2g / ^{m 2} ~40g / m 2 A method for producing a fiber reinforced substrate laminate, comprising producing a reinforced fiber substrate laminate through at least the following steps (A) to (F) using the reinforcing fiber substrate.
(A) A cutting step of cutting the reinforcing fiber base into a predetermined shape.
(B) A laminating process in which the reinforcing fiber base material cut into the predetermined shape is sequentially transported and arranged on a plane based on a predetermined laminating configuration.
(C) The conveyance process which conveys the laminated body obtained by (B) intermittently to a heating process.
(D) The heating process which heats the conveyed laminated body.
(E) The surface of the reinforcing fiber substrate is pressed using a pressing jig having a region where the area ratio of the pressing part having a high area per fixed area of the pressing jig is 1 to 10%. A pressure bonding step in which the reinforcing fiber bases of the pressure portion are bonded in the thickness direction with the resin containing the thermoplastic resin adhering to the surface.
(F) A cooling step for cooling the laminate.

  (9) The area ratio of the pressurizing unit per fixed area of the pressurizing jig that pressurizes the end region having a width of 1 to 5 cm from the end portion of the reinforcing fiber base laminate is other than the end region. The method for producing a fiber-reinforced substrate laminate according to (8), which is 1.5 to 5 times the area ratio of the pressing portion per fixed area of the pressing jig to be pressed.

  The reinforcing fiber base laminate of the present invention has good handleability, excellent shapeability even in a three-dimensional shape, and a molded article using the reinforcing fiber base laminate of the present invention is excellent. Has mechanical properties.

  Hereinafter, the present invention will be specifically described with reference to the drawings.

  FIG. 1 is a perspective view showing an example of a reinforcing fiber base laminate of the present invention, and FIG. 2 is an example of a highly bonded region in the reinforcing fiber base laminate of the present invention. FIG. 3 is a cross-sectional view showing an example of the reinforcing fiber base laminate of the present invention.

  The reinforcing fiber substrate laminate 2 of the present invention is formed by laminating a plurality of sheet-like reinforcing fiber substrates 1.

  Examples of the form of the reinforcing fiber base 1 include woven fabric (unidirectional, multiaxial) and knitted fabric. Among them, a unidirectional or 2- to 4-axis woven fabric is preferable because a molded product having high mechanical properties can be obtained. In addition, it is preferable to use a biaxial plain weave as a multiaxial woven fabric because it can be used for various industrial applications including automotive applications where design demands are strong.

The basis weight of the reinforcing fiber substrate 1 is preferably 100 to less than 1000 g / m ² because the handleability is good and the manufacturing cost can be reduced. Moreover, as long as the desired mechanical characteristics of the molded article made with the reinforcing fiber base laminate 2 can be obtained, the reinforcing fiber bases 1 having different basis weights may be appropriately combined.

  The reinforcing fiber of the reinforcing fiber base 1 is a multifilament, and the type thereof is not particularly limited. For example, glass fiber, alumina fiber, silicon carbide fiber, metal fiber, organic (polyaramid, PBO, liquid crystal polymer fiber, PVA, PE polyphenylene sulfide fiber, etc.) fiber or carbon fiber can be preferably used. Among these, carbon fibers are particularly preferred as reinforcing fibers for structural materials such as aircraft and automobiles because carbon fibers are excellent in specific strength and specific elastic modulus and excellent in water absorption resistance. Among them, when the tough carbon fiber is used, the impact-absorbing energy of the reinforced fiber plastic to be molded becomes large, so that it can be applied not only to various industrial uses but also as an aircraft primary structural material.

  Moreover, it is preferable that the reinforcing fiber base laminate 2 of the present invention has a planar shape. The flat shape here is defined as a flat shape if it is wound around a paper tube or the like and then returns to a flat shape when unwound. As described above, when the reinforcing fiber base laminate is wound around a paper tube and then unwound, some curl may remain and may not be a strict flat surface. If the material laminate has a primary curved surface shape and the radius of curvature is 50 cm or more in a portion of 50% or more, it is regarded as a flat surface.

  Further, the reinforcing fiber base laminate 2 of the present invention has joints distributed over the entire surface of the laminated layer 3. The joint means that the reinforcing fiber base 1 and the reinforcing fiber base 1 constituting each interlayer 3 are fixed. As a means, adhesion by resin, entanglement of raised fibers, fixing by stitch yarn Etc. Among them, the adhesion by the resin is preferable because it can be joined again by mechanically removing the joining or heating and pressing. Also, the fact that the joints are distributed over the entire surface means that the entire surface is not joined without a gap, but the joints and non-joint parts are mixed on the entire surface. As such distribution form, non-joined portions may be interspersed while the joined portions are continuous, or joint portions may be interspersed while the non-joined portions are continuous. For example, since the ratio of the connection portion between the layers can be easily controlled, a high bonding region and a low bonding region described later can be easily set.

The reinforcing fiber base laminate 2 of the present invention includes a high bonding region having a bonding force of 500 to 1000 N / m ² and a low bonding region in which the density of distribution of bonding portions is lower than that of the high bonding region as the bonding form between the layers. Formed from. By comprising such two regions, it is possible to achieve both the following property to the shape when forming into a preform and the handling property that it is difficult to disconnect the layers during handling such as carrying. That is, when the high-bond region 5 is transported with a hand, a tool, a machine, or the like, or when it is set on a mold, the high-bonding region 5 is easily peeled off (such as the end of the reinforcing fiber base 1 or It is preferable to set the base material to the base material joining portion 7 shown in FIG. 2 because the handling property can be particularly improved. Further, in the subsequent preforming step, if the high bonding region 5 is set at a location where the reinforcing fiber base laminate 2 is cut into a desired shape, peeling of the base material can be prevented even after the shape cut. The bonding force in such a high bonding area needs to be 500 to 1000 N / m ² . When the bonding force of the high bonding region 5 is less than 500 N / m ² , the reinforcing fiber base material 2 is peeled from the end of the reinforcing fiber base material 1 during transportation or handling, resulting in 1000 N / m ^2. This is because slipping along the bent portion is less likely to occur during shaping and wrinkles occur.

  The term “bonding force” as used herein refers to the stress required to peel off the laminated layer 3. Hereinafter, a method of measuring the bonding force will be described with reference to FIG.

  First, a test piece (N number 5, standard 100 mm square, but can be changed as appropriate) is cut out from the reinforcing fiber base laminate 2 and a SUS plate 27 (test piece) having sufficient rigidity on both upper and lower surfaces of the test piece. The test body 29 is manufactured by adhering the entire surface with an adhesive such as a double-sided tape 28. The adhesive strength of the double-sided tape 28 is not particularly limited as long as it can be adhered so that the test piece and the upper and lower double-sided plates are not peeled off before the interlayer of the reinforcing fiber base laminate 2 during the test. It is preferable that it is 30 N / 25mm or more by the measuring method based on 0237 (2000) (90 degree | times adhesive force, SUS board).

Next, the lower surface of the test body 29 is fixed to the pedestal 30 of the tensile tester with the double-sided tape 28, and the tensile tester mounting jig 31 is bonded to the center of the upper surface with the double-sided tape 28. Here, care is taken that the central axes of the test body 29 and the mounting jig 31 are aligned.
Finally, the mounting jig 31 is set in a tensile testing machine, a load is applied parallel to the central axis at a speed of 25 mm / min, and the maximum load (N) when the interlayer 3 is peeled is read.

  The test result is calculated from the following calculation formula to obtain the bonding force.

  How to distinguish the high junction region 5 and the low junction region 6 will be described as follows with reference to FIG.

  First, the longitudinal direction 32 of the reinforcing fiber base laminate 2 (that is, the longest direction in the reinforcing fiber base laminate 2, for example, in the case of a rectangle means the direction of the long side, but in the case of a square Specifies the direction of any side, the direction of the longest side in the case of a polygon, the direction of the major axis in the case of an ellipse, and the direction that can be evaluated as the longitudinal direction in the case of a circle) A direction perpendicular to the direction is defined as a width direction 33. At a location having a distance of at least 10 mm or more from the end in the length direction and the largest number of test pieces being cut out in the width direction 33, the reinforcing fiber base laminate 2 extends in the width direction 33, and the width is 50 mm and the length is 150 mm. The test pieces 34 are cut out at equal intervals, and the distribution of the bonding force in the width direction 33 is obtained based on the measurement method. If the width is such that ten or more test pieces 34 cannot be created, a test piece 34 (the length is three times the width) is created so that the number of test pieces is ten.

Thereafter, the number of test pieces 34 (high bonding region 5) having a bonding force of 500 to 1000 N / m ² , which is obtained by measuring the area of the reinforcing fiber base laminate 2 based on the measurement method using these test pieces 34, And the density (namely, the area or number of the junction part per unit area) which the junction part 4 contained in the test piece 34 distributes is calculated | required.

In the present invention, as a result of the above measurement, the density of the joints 4 included in the other test pieces 34 (that is, the density of the joints 4 included in the other test pieces 34 (ie, the density of the joints 4 included in the test pieces 34 of 500 to 1000 N / m ² )). The area or the number of joints per unit area) only needs to be low. In this case, the joint strength is 500 to 1000 N / m ² and the density of joints distributed from the high joint area 5 is high. It can be evaluated that the low low junction region 4 is formed.

It is preferable that the high junction region 5 is 1 to 10% in the laminated layer 3. If the range of the high bonding region 5 is less than 1%, the effect of preventing the peeling of the base material is small, and if it is above 10%, it is difficult for slippage between the laminated layers along the bent portion to occur during shaping. Therefore, if the conditions are not set strictly, there is a case where wrinkles occur. In addition, the ratio between the lamination | stacking layers of the high junction area | region 5 said here shall be the ratio which remove | divided the number of the test pieces (high junction area | region 5) whose joining force is 500-1000 N / m < ² > by the total number of test pieces.

The distribution of the joint portions 4 between the laminated layers 3 of the reinforcing fiber base laminate 2 is particularly limited as long as the above-described effects are obtained and the joint strength of the high joint region 5 is 500 to 1000 N / m ^2. However, it is preferable that it is distributed with a certain interval over the entire surface between the layers. Since the joints are distributed at a certain interval, the joints between the layers 3 are also partially made, and a degree of freedom is created. As a result, slipping between the laminated layers that easily follows the bent part is likely to occur during shaping.

  The interval between the joining portions 4 is preferably 1 to 30 mm, more preferably 3 to 10 mm in the high joining region 5 because workability at the time of joining is good and a desired joining force is easily obtained. Moreover, in the low joining area | region 6, the space | interval of the junction part 4 has preferable 15-100 mm. If the distance between the joining portions 4 is larger than 100 mm, the joining distance is too wide, so that the effect of partial joining cannot be obtained, and the interlayer of the base material slips during conveyance, which is not preferable.

The individual shape of the joint portion 4 is not particularly limited as long as a desired joining force can be obtained, and a spherical shape or a rectangular shape with chamfered corners is preferable. If the area of the joint is too large, the degree of freedom between the layers will be reduced and it will be difficult for slippage between layers to prevent wrinkles. If the area of the joint is too small, the desired bonding strength will be obtained. Since it is necessary to increase a pressurizing part, 1-100 mm < ² > is preferable and if it is 1-50 mm < ² >, it is more preferable.

FIG. 3 is a cross-sectional view showing the case where the joint in FIG. In such an embodiment, the above-described resin for bonding the laminated layers is preferably a resin containing a thermoplastic resin having a glass transition temperature Tg of 0 to 95 ° C. (hereinafter sometimes referred to as an adhesive resin). Resin 8 having a glass transition temperature Tg over the whole surface of the stacked layers 3 of reinforcing fiber base material contains a thermoplastic resin is 0 to 95 ° C. are attached within the ^{2g / m 2 ~40g / m 2} , In addition, the bonded portion is made to be in a softened or melted state by applying heat to the resin 8 in the interlayer 3 and then pressure-bonded or fused to both the reinforcing fiber base 1 and the reinforcing fiber base 1. It is formed by.

Further, the reinforcing fiber base material 1 of the present invention, on at least one side surface, the resin 8 containing a thermoplastic resin having a glass transition temperature Tg of 0 ° C. to 95 ° C. ^is at 2g / ^{m 2} ~40g / m 2 It is characterized by being attached. By arranging the resin containing such a thermoplastic resin, not only the mechanical properties described later can be improved, but also the laminated layers between the reinforcing fiber bases can be adhesively bonded with the resin containing the thermoplastic resin. When the Tg of the resin 8 containing the thermoplastic resin is less than 0 ° C., the resin 8 is sticky at room temperature, resulting in a reinforced fiber substrate 1 that is difficult to handle. On the other hand, when the Tg of the resin exceeds 95 ° C., there is no stickiness at room temperature, but it is necessary to increase the heating temperature for joining the reinforcing fiber bases 1 to each other, which makes it difficult to join. Here, Tg refers to a value measured by a differential scanning calorimeter DSC (Differential scanning calorimetry). Specifically, according to JIS-K7121 (1987), the measurement is performed using a Pyris1 DSC (manufactured by Perkin Elmer) at a heating rate of 40 ° C./min in a nitrogen atmosphere.

  In particular, the material for the primary structural material of the aircraft is preferably subjected to a compression after impact (Compression After Impact), so that it is not easily affected by the impact of the flying object or the damage of the tool during the repair. (Hereinafter referred to as CAI) is required to be high.

  Since the resin 8 containing the thermoplastic resin adheres to the surface of the reinforcing fiber base 1, it is contained between the layers of the reinforcing fiber base 1 constituting the FRP even after molding of the FRP. It is easier to form the interlayer 3 than in the case where no is used. Since the interlayer 3 includes the resin 8 in addition to the matrix resin, when a high-toughness thermoplastic resin is used, the interlayer can be selectively made tough. By increasing the toughness between layers, energy can be absorbed by deformation or destruction of the layers when an impact is applied to the FRP, so that CAI can be improved. Therefore, by optimizing the resin 8 to be attached to the surface of the reinforcing fiber base 1, not only the bondability but also the impact resistance absorption characteristics can be improved.

When the adhesion amount of the resin 8 containing the thermoplastic resin is less than 2 g / m ² , the adhesion amount is too small and sufficient adhesive bonding is not exhibited. On the other hand, when the adhesion amount is more than 40 g / m ² , the adhesion amount is too large, the weight of FRP increases, and the weight reduction is impaired. As the resin 8 containing a thermoplastic resin adhering to the surface of the reinforcing fiber base 1, a mixture with a thermosetting resin can be used. In the case where only adhesive bonding between the reinforcing fiber bases is required, a thermoplastic resin may be used alone as the resin 8, but in the case where impact resistance such as CAI is required, toughness When using a mixture of an excellent thermoplastic resin and a thermosetting resin that is easily reduced in viscosity and easy to adhere to the reinforcing fiber base, it has adhesiveness to the reinforcing fiber base 1 while having appropriate toughness be able to.

  As such a thermosetting resin, an epoxy resin, an unsaturated polyester resin, a vinyl ester resin, a phenol resin, or the like can be used. The thermoplastic resins include polyvinyl acetate, polycarbonate, polyacetal, polyphenylene oxide, polyphenylene sulfide, polyarylate, polyester, polyamide, polyamideimide, polyimide, polyetherimide, polysulfone, polyethersulfone, polyetheretherketone, polyaramid. Polybenzimidazole, polyethylene, polypropylene, cellulose acetate and the like can be used.

  Examples of the form of the resin 8 containing a thermoplastic resin include particles, fibers, and films. Especially, the form of particle | grains is preferable from the point which can make the reinforcement fiber volume ratio in a preform high. If the average diameter (average short diameter in the case of an ellipse) is small, the particles can be uniformly dispersed on the surface of the reinforcing fiber base laminate 2, and therefore, the diameter is preferably 1 mm or less, preferably 250 μm or less. Is more preferable, and 50 μm or less is more preferable. As the diameter of the particles arranged on the surface of the reinforcing fiber base laminate 2 increases, the surface unevenness increases and the reinforcing fibers may be bent. Therefore, the surface of the reinforcing fiber base laminate 2 on which the reinforcing fibers are arranged The average thickness of the particles is preferably in the range of 5 to 250 μm.

  The high bonding region 5 preferably has a width of 1 to 5 cm from the end of the reinforcing fiber base laminate. If the width from the edge is higher than 5 cm, slipping along the bent part may not occur easily during shaping, and if it is less than 1 cm, it is difficult to obtain the effect of preventing peeling of the substrate edge. There is.

  The term “end portion” as used herein refers to an end portion in the longitudinal direction or the width direction, and can be appropriately selected within a range in which a desired effect can be obtained. Further, when the preform has a width of 1 to 5 cm at the end region, workability is good when the vicinity of the center of the end region is cut.

  In addition, the bonding strength of the end region having a width of 1 to 5 cm of the reinforcing fiber substrate laminate 2 is 1.5 to 5 times that of the low bonding region, so that the end of the substrate is not peeled and the handleability is good. In particular, it is preferable because slippage between the laminated layers is likely to occur along the bent portion at the time of shaping.

  The joining over the entire surface of the laminated layers of the reinforcing fiber base laminate 2 is not particularly limited as long as a desired joining force can be obtained, and stitching integration with stitch yarns is also possible. When the stitches are stitched together with stitch yarns, there is a degree of freedom for slippage between the respective layers. Therefore, the reinforcing fiber yarns are not locally bent even if they are along the curved surface.

Examples of the stitch structure formed by the stitch yarn upon the stitching integration include single ring stitching and tricot stitching. In addition, if the stitching density of the stitch yarn is made larger in the high bonding area 5 than in other areas, it is easy to obtain a desired bonding force. The stitch yarn driving density here refers to the number of stitch yarns driven per unit area, and is defined by the driving pitch in the length direction and the driving pitch in the width direction.
In the high bonding region 5, since the base material does not peel during handling and the shapeability is not impaired, the driving pitch in the length direction is preferably 1 to 6 mm, and the driving pitch in the width direction is preferably 2 to 10 mm. In the other regions, the stitching yarn is loosely restrained between the layers of the reinforcing fiber base laminate 2 and the form becomes unstable, and the layer is displaced during transportation, so the driving pitch in the length direction is 3 to 10 mm. The driving pitch in the width direction is preferably 3 to 40 mm.

In addition, even in the case of joining between laminated layers by stitching integration with stitch yarn, a resin 8 containing a thermoplastic resin having a glass transition temperature Tg of 0 to 95 ° C. over the entire surface of the laminated layers 3 of the reinforcing fiber base is it allows for form fixed after preform of which will be described later adhered within the ^{2g / m 2 ~40g / m 2} .

It is preferable that the reinforcing fiber base laminate 2 of the present invention has a laminated configuration that constitutes the FRP. However, when the number of laminates constituting the FRP is very large, the reinforcing fiber substrate laminate is provided. 2 may be a laminated structure constituting a part of the laminated structure constituting the FRP. For example, when the laminated structure constituting the FRP is [(45/0 / −45 / 90) _x ] _s (X is an arbitrary integer), it is a repetitive laminated unit (45/0 / −45 / 90) You may laminate | stack the reinforcement fiber base material laminated body 2 which has a laminated structure only for a required part.

  Thus, since the reinforcing fiber base laminate 2 of the present invention is excellent in formability and handleability, a high-quality preform can be obtained. In the present invention, the preform is not a flat reinforcing fiber base material laminate, but an intermediate that is shaped like the shape of the final product or a shape close to it using a shaping die or a similar die. Means that.

  In the method of molding the FRP by injecting the matrix resin into the preform as in the present invention, it is not an exaggeration to say that the quality of the FRP is determined by the preform, so a high quality preform is obtained. The reinforcing fiber base laminate 2 that can be used is very important.

  The preform of the present invention is preferably obtained by shaping the reinforcing fiber substrate laminate 2 of the present invention, and the reinforcing fiber volume fraction Vpf is preferably in the range of 40% to 62%.

  If the reinforcing fiber volume fraction Vpf is less than 40%, the preform becomes bulky, and the reinforcing fiber volume fraction of the FRP that is a molded product may be lowered. On the other hand, when the reinforcing fiber volume fraction Vpf is larger than 62%, it is difficult to impregnate the matrix resin, and defects such as non-impregnation and voids are likely to occur. The volume ratio of the reinforcing fiber in the preform is such that, after the reinforcing fiber base laminate 2 is shaped using a shaping mold or the like, it is heated at a temperature higher than the glass transition temperature of the resin containing the thermoplastic resin, It can be improved by applying pressure such as pressing pressure for a certain period of time. In this case, the higher the heating temperature and pressure and the longer the heating / pressurizing time, the higher the reinforcing fiber volume fraction can be improved. By appropriately controlling the heating temperature, pressure, and heating and pressing time, it is possible to control the reinforcing fiber volume fraction of the preform.

  Further, the preform of the present invention will be described below with reference to an example of a specific method for producing such a preform in which the reinforcing fiber base layer is preferably bonded substantially over the entire surface.

  First, the reinforcing fiber base laminate 2 is cut into a desired shape. At this time, if the region including the shape cut portion is set as the high bonding region 5 in advance, the base material is not peeled after the shape cut, and the handling property can be prevented from being lowered. Next, the reinforcing fiber base laminate 2 after the shape cut is placed in a shaping mold, and then the entire reinforcing fiber base laminate is covered with a bagging film (or rubber sheet) to laminate the bagging film and the reinforcing fiber base. A vacuum is drawn between the body and the whole of the reinforcing fiber base laminate is made to be in close contact with the shaping mold by applying atmospheric pressure. Alternatively, a preform can be produced by applying pressure to the reinforcing fiber base laminate using a shaping mold and a press. Thus, since the preform is adjusted to a final product or a shape close thereto, after the shape is adjusted, it is necessary to maintain the shape until the matrix resin is injected and molded into FRP. Therefore, the reinforcing fiber base material 1 or the reinforcing fiber base material laminate 2 is shaped into a shaping mold or the like and arranged into a preform shape, and then the reinforcing fiber base material layers are bonded substantially over the entire surface. This is preferable because the shape of the preform is easily retained.

  Next, in the FRP production method of the present invention, a matrix resin is injected into a preform having a reinforcing fiber volume ratio of 40% to 62% that is preferably used in the present invention, and the matrix resin is discharged from the vacuum suction port. If the injection of the matrix resin from the inlet is stopped and the discharge amount of the matrix resin from the vacuum suction port is adjusted, the FRP reinforcing fiber volume fraction Vf can be molded to 35% to 72%.

  There is no particular limitation on the reinforcing fiber volume fraction Vf of the FRP to be obtained, but if it is lower than 35%, the strength and elastic modulus of the FRP tend to be low, and a thickness is required to express the predetermined mechanical properties. As a result, there is a concern that the effect of weight reduction is reduced.

  On the other hand, if the reinforcing fiber volume fraction Vf is higher than 72%, defects such as voids may easily occur due to the amount of the matrix resin being too small.

  In addition, when molding FRP with a large number of laminated sheets, such as the number of laminated reinforcing fiber bases constituting the FRP, more than 20 sheets, ensuring the injection time into the preform in consideration of the curing characteristics of the matrix resin In addition, it is also preferable to inject the matrix resin while heating and reducing the viscosity. It is also preferable to heat the preform into which the matrix resin is injected at the same time. When a preform having a high reinforcing fiber volume fraction Vf is used to form an FRP having a relatively high reinforcing fiber volume fraction Vf, the reinforcing fiber density of the preform increases, and the impregnation property of the matrix resin tends to decrease. It is in. Even in this case, it is preferable to lower the viscosity by heating the matrix resin, and to inject and impregnate it.

  More preferably, after stopping the injection of the matrix resin from the injection port, the injection port is vacuumed, the matrix resin is sucked and discharged from both the injection port and the conventional vacuum suction port, and the discharge amount of the matrix resin To adjust the FRP reinforcing fiber volume fraction Vf to 35% to 72%.

  When discharging the matrix resin from the injection port and / or the vacuum suction port, it is also preferable to pressurize the preform from the outside and discharge the matrix resin in a shorter time.

  Further, the reinforcing fiber volume fraction Vf of FRP is preferably adjusted to the reinforcing fiber volume fraction Vpf−5% to Vpf + 20% of the preform. The reinforcing fiber volume fraction of FRP is determined by the time and temperature at which the matrix resin is sucked from the suction port and / or the vacuum suction port after injecting the matrix resin into the preform, and further the external pressurization to the preform. It is possible to control the discharge amount of the matrix resin.

  The reinforcing fiber base 1 used in the present invention has a resin 8 containing a thermoplastic resin attached to the surface, and the resin adheres the reinforcing fiber bases to each other, and the reinforcing fiber base laminate 2 and the plug. In addition to the function of improving the handleability such as the shape retention of the reform, the function of improving the impact resistance performance such as CAI is developed. When such an adhesive resin is expected to have improved impact resistance, it is preferable that a layer containing the adhesive resin is formed between the reinforcing fiber layers after molding the FRP.

  On the other hand, the FRP reinforcing fiber volume fraction Vf can be improved by increasing the discharge amount of the matrix resin at the time of manufacturing the FRP. However, when the matrix resin is injected, the matrix resin and / or the plug as described above are used. The reform may be heated and poured. When the heating temperature exceeds the glass transition temperature of the resin containing the thermoplastic resin adhering to the surface of the reinforcing fiber base 1, the resin softens and falls off from the surface of the reinforcing fiber base 1 and strengthens. In some cases, it is disposed in a matrix resin that forms the interlayer 3 of the fiber substrate 1.

  In such a case, if the discharge amount of the matrix resin is increased in order to make the reinforcing fiber volume fraction Vf of the FRP higher than that of the preform reinforcing fiber volume fraction Vpf + 20%, If the adhesive resin attached to the surface of the resin falls off and is placed in the matrix resin or is compatible with the matrix resin, it is contained in the matrix resin. There is a concern that a resin containing a thermoplastic resin may also be discharged. The discharge of the resin 8 containing the thermoplastic resin accompanying the discharge of the matrix resin is such that the function of the resin 8 improves the handling of the reinforcing fiber base laminate 2 and / or the preform until the FRP is molded. However, there is no problem when there is no function as an element constituting FRP, but when a resin containing a thermoplastic resin is expected to exhibit functions such as improving the impact resistance characteristics of FRP. It is not preferable.

  On the other hand, the function of the resin 8 containing the thermoplastic resin only improves the handleability of the reinforcing fiber base and / or preform until the FRP is molded, and does not expect a function as an element constituting the FRP. In such a case, the matrix resin and the preform are heated, and the resin 8 is removed from the surface of the reinforced fiber base material or is dissolved in the matrix resin. It is also a preferable aspect to discharge the water. As described above, since the resin 8 easily forms the interlayer 3 of the reinforcing fiber base 1 constituting the FRP, the impact resistance characteristic of the FRP is improved, but there is a concern that the improvement of the reinforcing fiber volume fraction Vf of the FRP is hindered. Yes, there is a concern that the compression and / or tensile property improvement due to the high reinforcing fiber volume fraction Vf of FRP is hindered. For this reason, it is possible to improve the compression and / or tensile properties by positively discharging the adhesive resin to suppress an increase in the thickness between the layers and obtaining a high reinforcing fiber volume fraction Vf.

  In addition, after the matrix resin is injected into the preform and the matrix resin is discharged from the vacuum suction port, the injection of the matrix resin is stopped from the injection port, and the injection port is also vacuumed, so that the injection port and the vacuum suction port It is also preferable to adjust the discharge amount of the matrix resin so that the reinforcing fiber volume fraction Vf of the FRP is 35% to 72%.

The “preform reinforcing fiber volume fraction Vpf” in the present invention is a value defined and measured as follows, and the preform refers to a state before the matrix resin is injected.
That is, the reinforcing fiber volume fraction Vpf of the preform can be expressed by using the following formula from the thickness (t) of the preform in a state where a pressure equivalent to atmospheric pressure of 0.1 MPa is applied to the preform.

Preform reinforcing fiber volume fraction Vpf = F × p / ρ / t / 10 (%)
here,
F: Base material weight (g / m ² )
p: Number of laminated substrates (sheets)
ρ: Density of reinforcing fiber (g / cm ³ )
t: Preform thickness (mm).

  As a specific method for measuring the thickness of the preform, the pressure should be changed to 0.1 MPa by the thickness measuring method described in the carbon fiber fabric test method described in JIS R 7602 (1995). Can be obtained. In the VaRTM molding method using vacuum pressure, the preform reinforcing fiber when pressure of 0.1 MPa corresponding to atmospheric pressure is applied to inject and impregnate the matrix resin in a state where atmospheric pressure is applied to the preform. It is preferable to control the volume ratio. When the preform has a complicated shape and cannot be measured based on JIS R 7602 (1995), a sample may be cut out from the preform and measured. In this case, it is necessary to cut out the sample with care so that the thickness of the preform does not change by cutting out. In addition, if it is impossible to cut out the sample, the preform and mold are placed under a pressure applied to the preform by vacuum bagging with a bagging film together with the mold shaped preform. It is also possible to measure the thickness of the preform by measuring the total thickness of the bagging film and subtracting the thickness of the mold and bagging film from the total thickness.

The “FRP reinforcing fiber volume fraction Vf” in the present invention is a value defined and measured by the following, and refers to a state after the matrix resin is injected into the preform and cured. That is, the measurement of the reinforcing fiber volume fraction Vf of FRP can be expressed from the thickness (t) of the FRP using the following formula in the same manner as described above.
Reinforced fiber volume fraction of FRP Vf = F × p / ρ / t / 10 (%)
Here, t is the thickness (mm) of the FRP, but the other parameters are the same as the parameter values for obtaining the reinforcing fiber volume fraction Vpf of the preform.
F: Base material weight (g / m ² )
p: Number of laminated substrates (sheets)
ρ: Density of reinforcing fiber (g / cm ³ )
t: FRP thickness (mm).

  If the basis weight F, the number of laminated base materials, and the density of the reinforcing fibers are not clear, the FRP reinforcing fibers can be obtained by either the combustion method based on JIS K 7075 (1991), the nitric acid decomposition method, or the sulfuric acid decomposition method. The volume ratio is measured. As the density of the reinforcing fiber used in this case, a value measured based on JIS R 7603 (1999) is used.

  A specific method for measuring the thickness of FRP is not particularly limited as long as it can correctly measure the thickness of FRP. However, as described in JIS K 7072 (1991), JIS B 7502 ( It is preferable to measure with a micrometer specified in 1994) or with a precision equivalent to or better than that. If the FRP has a complicated shape and cannot be measured, a sample (a sample having a certain shape and size for measurement) may be cut out from the FRP and measured.

  In addition to the conventional vacuum suction port, suction and discharge of the matrix resin from the injection port is preferable because the discharge time of the matrix resin can be shortened.

  In addition, when the matrix resin is sucked and discharged only from the vacuum suction port, it is easy to suck the matrix resin impregnated in the preform near the vacuum suction port, but it is impregnated in the preform near the injection port. Since the matrix resin is difficult to suck, it is difficult to discharge. Therefore, as a result, there is a concern that the reinforcing fiber volume ratio of the FRP near the inlet is lower than the reinforcing fiber volume ratio of the FRP near the vacuum suction port. For this reason, after the matrix resin is injected into the preform, the matrix resin is sucked and discharged also from the injection port, so that the variation in the reinforcing fiber volume ratio in each part of the FRP can be improved.

In the method for producing a reinforcing fiber base of the present invention, a resin containing a thermoplastic resin having a glass transition temperature Tg of 0 ° C. to 95 ° C. on the surface of at least one side of the reinforcing fiber base is 2 g / m ^{2 to} 40 g / The reinforcing fiber base laminate adhered within the range of m ² is manufactured.
The method for producing a reinforcing fiber base laminate is characterized by producing at least the following steps (A) to (F).
(A) A cutting step of cutting the reinforcing fiber base into a predetermined shape.
(B) A laminating process in which the reinforcing fiber base material cut into the predetermined shape is sequentially transported and arranged on a plane based on a predetermined laminating configuration.
(C) The conveyance process which conveys the laminated body obtained by (B) intermittently to a heating process.
(D) The heating process which heats the conveyed laminated body.
(E) The surface of the reinforcing fiber substrate is pressed using a pressing jig having a region where the area ratio of the pressing part having a high area per fixed area of the pressing jig is 1 to 10%. A pressure bonding step in which the reinforcing fiber bases of the pressure portion are bonded in the thickness direction with the resin containing the thermoplastic resin adhering to the surface.
(F) A cooling step for cooling the laminate.

  The predetermined shape of the reinforcing fiber base referred to in (A) is a shape in which the reinforcing fiber base 1 has fiber orientation at a lamination angle of each layer, and has a constant width and a continuous length. By obtaining the reinforcing fiber base laminate 2 having a constant width and a continuous length, the obtained reinforcing fiber base laminate 2 can be wound around a paper tube and efficiently stored, and a member to be applied later This is because, when the width is within the width of the reinforcing fiber base laminate, it can be applied to any member by cutting according to the shape of the member.

  In addition, the predetermined laminated structure referred to in (B) means a laminated structure common to the respective members to which the reinforcing fiber base laminate 2 is applied. By manufacturing a laminate having a common laminate configuration, the reinforcing fiber base laminate 2 can be used for more members.

  Next, FIG. 4 shows an embodiment of the manufacturing apparatus of the present invention, and the manufacturing method will be described.

That is, in FIG. 4, as an example, an example of an apparatus for producing the reinforcing fiber base laminate 2 having a laminated configuration [45/0 / −45 / 90] _s (where S means mirror symmetry) is shown.

  A commercially available automatic cutting machine can be used for cutting the reinforcing fiber base in the cutting step (A).

  In the lamination step (B), it is preferable that the cut reinforcing fiber base material 1 is transported and arranged at a predetermined position of the conveyor 10 by using the robot arm 9. A hand device 11 that can hold the reinforcing fiber base 1 is attached to the tip of the robot arm 9. The hand apparatus 11 will not be specifically limited if it has the function which can be conveyed and arrange | positioned, without impairing the quality of the said reinforced fiber base material 1. FIG. For example, a method of holding the reinforcing fiber substrate 1 by suction by connecting a vacuum suction device or a blower device to a hand device, a method of hooking and holding the reinforcing fiber substrate 1 by a pin, and these two methods A combined method or the like is applicable.

  In particular, the hand device 11 using a vacuum suction device or a blower device is preferable because the reinforcing fiber base material is not caught by a pin or the like, and there is no fear of reducing the quality of the reinforcing fiber base material.

After the reinforcing fiber base material 14 having a lamination angle of 45 ° cut by the automatic cutter 13 is disposed at a predetermined position of the conveyor 10, the conveyor 10 is operated and moved in the traveling direction, and the previously disposed lamination angle 45 is disposed. Similarly, the reinforcing fiber base material 14 having a lamination angle of 45 ° is arranged in a space adjacent to the reinforcing fiber base material 14. A reinforcing fiber substrate having a lamination angle of 0 ° is arranged on the reinforcing fiber substrate 14 having a lamination angle of 45 ° based on the lamination configuration. The 0 ° reinforcing fiber substrate is preferably arranged and laminated directly from the raw material roll 12 without cutting. After laminating the 0 ° reinforcing fiber base material, the conveyor 10 was operated in the same manner, and the 45 ° / 0 ° reinforcing fiber base material was laminated, and was cut by the automatic cutter 17 at −45 °. The reinforcing fiber substrate 18 is conveyed and laminated. Similarly, the 90 ° reinforcing fiber base material 16 cut by the automatic cutter 15, the −45 ° reinforcing fiber base material 18 cut by the automatic cutter 17, and the 0 ° reinforcing fiber base material are laminated. Laminate based on.
In this way, the reinforcing fiber base material constituting each layer is arranged, and the reinforcing fiber base material is moved intermittently, which is moved by a conveyor. Moreover, in order to arrange the reinforcing fiber base material to be further laminated on the moved destination, the robot arm 9 is installed on the slider 19 that can move in the same direction as the conveyor 10 advances, It is preferable that each reinforcing fiber substrate can be conveyed to a predetermined position on the conveyor.

  Although all the reinforcing fiber bases may be cut by a single automatic cutting machine, by cutting the reinforcing fiber bases of each lamination angle using a plurality of automatic cutting machines as shown in FIG. This is preferable because the time required for the cutting process can be shortened.

  In this way, the reinforcing fiber base based on a predetermined laminated configuration is automatically and accurately reinforced continuously by repeating cutting with an automatic cutting machine, transportation and placement with a robot arm, and movement with a conveyor 10. Since a fiber base material can be laminated | stacked, it is preferable. As such accuracy, the orientation angle of the reinforcing fiber base is preferably within ± 1 °, and the gap when the next reinforcing fiber base is placed next to the previously placed reinforcing fiber base is 0 to 0. It is preferably 1 mm.

  (C) In a conveyance process, the laminated body obtained at the lamination process of (B) is conveyed to the heating process of (D). In FIG. 5, the reinforcing fiber base laminate 2 having a predetermined laminated configuration arranged on the conveyor 10 is conveyed into the oven 20 by operating the conveyor 10 in the traveling direction intermittently. . Since the laminated bodies laminated in a predetermined laminated structure are not yet integrated, it is difficult to carry a laminated body having a continuous length without shifting the lamination angle. After laminating the materials, it is preferable to continuously convey the materials to an oven. By adopting such means, it is possible to transfer to the heating step and the pressure bonding step without shifting the stacking angle.

  If there is a concern that the stacking angle may shift due to movement on the conveyor before the adhesive integration in the pressure bonding process of (E), temporarily sew the end part with a sewing machine, etc. Stopping is also one of the preferred modes. In the case of temporary stitching, after adhering a predetermined portion over the entire surface of the laminate in the subsequent pressure bonding step, the end portion of the temporary stitching is cut off and removed, whereby the reinforcing fiber base laminate of the present invention is removed. Obtainable.

  In the heating step (D), the laminated body obtained in the laminating step (B) is heated at a predetermined temperature to be described later. As the heating device, a hot air oven is preferable because it can heat the reinforcing fiber base without contact.

  In the subsequent pressure bonding step (E), the range to be bonded may be selectively heated using an oven 20 as described in FIG. By using such an oven 20 to selectively heat the area to be bonded, not only the heating efficiency is improved, it is easy to control the heating conditions, the heating equipment is downsized, and the conveyor 10 is attached. Is preferable because it has advantages such as ease. Moreover, if the heat generating function is provided in the pressure bonding jig 21 described later, the oven 20 may not be used. By directly heating the laminate with the pressure bonding jig 21 having a heat generating function, it can be efficiently heated. It is preferable that the heating is uniformly performed in the entire pressure bonding portion of the laminate. In particular, it is preferable to heat to a uniform temperature in the thickness direction of the part to be pressure bonded. If the temperature is not uniform in the thickness direction, the heating of the resin 8 adhering to the surface of the reinforcing fiber base 1 is not uniform, and the bonding force in the thickness direction varies, which is not preferable. Here, uniform means within ± 5 ° C. More preferably, it is within ± 3 ° C. The measuring method is not particularly limited, but by placing a thermocouple between the surface layer and the interlayer of the laminate at a representative heating location of the laminate, performing a heat treatment, and monitoring the overheating state of the laminate. Can be measured.

  Moreover, it is preferable that the predetermined temperature at the time of heating is higher than the glass transition temperature Tg of the resin adhering to the surface of the reinforcing fiber substrate 1. By making the heating temperature higher than the glass transition temperature of the resin, the resin 8 is softened. Therefore, in the pressure bonding step (F), it is possible to bond more reliably at a lower pressure, which is preferable. More preferably, it is glass transition temperature Tg + 5-20 degreeC.

  In the pressure bonding step (E), pressurization is performed using a pressure jig having 1 to 10% of a region having a high area ratio of the pressure part per fixed area of the pressure jig, It is necessary to adhere the reinforcing fiber bases of the pressurizing part in the thickness direction with the resin 8 containing the thermoplastic resin adhering to the surface. As the area where the area ratio of the pressurizing part is high, the part corresponding to the part where the base material is easily peeled is preferable. The part etc. which correspond to the shape cut part in a process can be mentioned.

  Here, FIG. 5 is used to show an example of a pressure bonding process of a pressure jig having a high area ratio of the pressure jig part that pressurizes the end region of the base material. That is, FIG. 5 shows a cross section of the pressure bonding jig 21, the reinforcing fiber base laminate 2, and the conveyor 10 installed in the oven 20 shown in FIG. 4.

The reinforcing fiber base laminate 2 on the conveyor 10 is transported to the pressure bonding jig 21 installed in the oven by operating the conveyor 10. The pressure bonding jig 21 includes an upper bonding jig 22 and a lower bonding jig 23, and the pressure bonding jig upper 22 has, for example, a convex independent pressure portion. The area of the pressing part is the area ratio of the pressing part per fixed area of the pressing jig that pressurizes the end region that is the width W (1 to 5 cm) from the end of the reinforcing fiber base laminate. It is preferable that it is 1.5-5 times or more with respect to the area ratio of the pressurization part per fixed area of the pressurization jig which pressurizes other than the said edge part area | region. The cross-sectional shape of the pressure unit 24 is preferably one that does not damage the reinforcing fiber substrate, and is preferably spherical or a rectangular shape with chamfered corners. If the area of the pressurizing part is too large, the degree of freedom between the layers will be reduced and it will be difficult for slippage between layers to prevent wrinkles. If the area of the crimping part is too small, the desired bonding strength will be obtained. 1 to 100 mm ² is preferable, and 1 to 50 mm ² is more preferable. The pressure bonding jig 21 is preferably made of metal and has a heat generating function. The heating method is not particularly limited, and examples thereof include a method in which an electric heater, hot water, or hot oil line is provided in the pressure bonding jig 21. It is preferable to make the pressure bonding jig 21 made of metal since the heating method or the temperature rising efficiency by the oven 20 can be improved.
Moreover, it is preferable that the pressurization part 24 can be removed from a viewpoint, such as adjusting maintenance, a change of pressurization conditions, etc.

  (F) In the cooling step, (D) heating step and (E) the adhesive resin bonding the reinforcing fiber substrates heated in the pressure bonding step is cooled to complete the bonding. In FIG. 5, by providing a cooling space 26 for cooling the reinforcing fiber base laminate at room temperature between the oven 20 and the winding roll 25, cooling is performed at room temperature to complete the bonding. After that, it is a step of winding with a roll 25 for winding. The roll 25 for winding is not particularly limited as long as it can wind up the reinforcing fiber base laminate, and a paper tube having an appropriate diameter can be used, but if the diameter is 50 to 150 cm. It is preferable. In addition, before winding up the reinforcing fiber base laminate as necessary, the reinforcing fiber base laminate is separated by deformation during winding by sewing the end of the laminate using a sewing machine or the like. This can be suppressed. In this case, the reinforcing fiber base laminate can exhibit a predetermined shaping performance by removing the sewn end as necessary.

  Further, without winding up the laminated body that has been bonded, it may be cut into a slit shape having a certain width or a cut shape used in a preform and stored in a stock shelf or the like. These steps (A) to (F) are preferably performed continuously by using the conveyor 10 because a reinforced fiber base material laminate having a continuous length can be produced.

  Hereinafter, the present invention will be described in more detail with reference to examples. In addition, this invention is not limited to the invention as described in an Example. In addition, the value of each parameter is obtained by the following method.

(1) Bonding force between laminated layers Determined by the method described in the text.

(2) Ratio between the laminated layers of the high-bonding region The width from the reinforcing fiber base laminate 2 is a portion having a distance of at least 10 mm from the end in the length direction and the largest number of test pieces in the width direction. A test piece having a width of 50 mm and a length of 150 mm was cut out at equal intervals in the direction, and the distribution of bonding force in the width direction was determined based on the measurement method described in the text. When the width was such that ten or more test pieces could not be produced, a test piece having a size that would result in ten test pieces (the length was three times the width) was produced. Then, the number of test pieces (high bonding region 5) having a bonding force of 500 to 1000 N / m ² measured based on the measurement method using these test pieces and the area of the reinforcing fiber substrate laminate 2, The density of the joints 4 included in the test piece (that is, the area or number of joints per unit area) was determined. Finally, the ratio between the laminated layers in the high bonding area was determined by dividing the number of test pieces (high bonding area 5) having a bonding force of 500 to 1000 N / m ² by the total number of test pieces.

(3) Glass transition temperature of resin Obtained by the method described in the text.

(4) Amount of resin adhesion The amount of resin adhesion was measured as follows. First, at least 1 ply of the reinforcing fiber base material is taken out from the reinforcing fiber base material laminate 2, and the base material is cut into 125 × 125 mm. The weight of the cut-out sample base material is measured to the 0.1 g unit with an electronic balance, and the base material total weight W (g / m ² ) = W 0 (g) / (0.125 × 0.125 (m ² )) is obtained. Asked.

Next, the sample substrate was placed in a container containing methylene chloride and immersed in methylene chloride to dissolve and remove the adhesive resin adhering to the substrate. After dissolving and removing the adhesive resin, the substrate was dried in a dryer at 110 ° C. ± 5 ° C. for 1 hour and cooled to room temperature in a desiccator. The cooled substrate was measured with an electronic balance, and the weight W1 (g) was measured to a unit of 0.1 g, and the substrate weight per unit area F (g / m ² ) = W1 (g) / (0.125 × 0.125 (m ² )). Finally, the resin adhesion amount was determined as resin adhesion amount (g / m ² ) = base material total weight W (g / m ² ) −base material weight F (g / m ² ).

(5) Preform reinforcing fiber volume fraction Vpf
The sample size was 300 × 300 mm, a preform was prepared as described in each example, and the reinforcing fiber volume fraction Vpf of the preform was determined as follows.

The density ρ (g / cm ³ ) of the reinforcing fiber is the density of the reinforcing fiber yarn used for the base material, and is measured in accordance with the method A of JIS R 7603 (1999).

  The thickness t (mm) of the preform is determined by placing the preform in a shaping mold, sealing it with a bag film, vacuuming the sealed space, and applying atmospheric pressure to the preform. Was used to measure 5 thickness gauges at the center and 4 corners of the preform up to 0.01 mm. The thickness of the center of the preform is measured by measuring the height of the center position of the preform from the top of the bag film with atmospheric pressure applied to the above preform. Measured by subtracting height and bag film thickness. The thickness of the four corners of the preform is measured in advance by measuring the combined thickness of the shaping mold, the preform, and the bag film with a micrometer in a state where atmospheric pressure is applied to the preform. It was measured by subtracting the thickness of the shaped mold and the thickness of the bag film.

Reinforcing fiber volume fraction Vpf of the preform is the base material weight F (g / m ² ), the number of laminated base materials p (sheet), the density of reinforcing fibers ρ (g / cm ³ ) Using the thickness t (mm) of the preform, the Vpf at which the thickness of the preform was measured was determined as Vpf = F × p / ρ / t / 10 (%), and the average value at the five locations was determined as the reinforcing fiber of the preform. It calculated | required as volume ratio Vpf.

(6) Reinforced fiber volume fraction Vf of FRP
FRP was produced as described in the Examples, and the reinforcing fiber volume fraction Vf of FRP was determined as follows. The base weight F and the density ρ of the reinforcing fibers are the same as described above.

  After removing the FRP from the mold, the thickness t (mm) of the FRP was measured at three locations around the epoxy resin injection port and the vacuum suction work center and between the injection port and the vacuum suction port using a micrometer. The thickness was measured up to 0.01 mm.

The reinforcing fiber volume fraction Vf of the FRP is the base material weight F (g / m ² ), the number of laminated base materials p (sheets), the density ρ (g / cm ³ ) of the reinforcing fibers, and the thickness of the FRP measured by the above method. Using t (mm), Vf = F × p / ρ / t / 10 (%).

Example 1
Below, the Example in the case of producing a preform using the reinforcing fiber base laminate 2 will be described.

First, a base material having a carbon fiber basis weight of 200 g / m ² was woven using carbon fibers having a tensile strength of 5800 MPa and a tensile modulus of 290 GPa and a filament number of 24,000. Next, 27 g / m ² is uniformly sprayed on the upper surface of the base material, containing thermoplastic resin having an average diameter of 120 μm and a glass transition temperature of 70 ° C. as an adhesive resin, and heated to 200 ° C. A reinforcing fiber substrate 1 was prepared by adhering to the surface.

  The reinforcing fiber substrate 1 is cut into a reinforcing fiber substrate 1 having a width of 1 m and a length of 1 m having a fiber direction angle of 45 ° direction, 0 ° direction, −45 ° direction and 90 ° direction. Direction, 0 ° direction, −45 ° direction, 90 ° direction, 90 ° direction, −45 ° direction, 0 ° direction, and 45 ° direction were sequentially laminated to prepare a laminate. This laminate was placed on a flat plate made of aluminum alloy and heated in an oven having an ambient temperature of 85 ° C. Moreover, the area | region 5 cm from the edge part of the base material was set to the edge part area | region as the high joining area | region 5. FIG.

After sufficiently heating the laminate, as shown in FIG. 5, the cross-sectional area of one pressing portion 24 is 1 mm ² , and the pitch of the pressing portions 24 that pressurize the high bonding area 5 is the width direction / length. A pressure bonding jig 21 having a pressure of 5 mm in both directions and a pressure of the pressure members 24 for pressing the low bonding area 6 in the width direction and the length direction of 20 mm is arranged on the laminate, and further pressure bonding treatment is performed. Pressurize the laminate for 10 minutes so that the pressure applied to one pressing part 24 on the tool 21 is 0.1 MPa, and bond the reinforcing fiber bases 1 to each other with the adhesive resin on the surface of the reinforcing fiber base 1. It joined partially over the thickness direction. Thereafter, the laminate was taken out of the oven and left to cool at room temperature to obtain a laminate of reinforcing fiber substrates. Here, a test piece having a width of 5 cm and a length of 15 cm was cut out from the high bonding region 5 (end region) of the laminate, and the bonding force was measured. As a result, it was 550 N / m ² .

  Next, a laminate having a width of 150 mm and a length of 1000 mm is cut out from the laminate, and the laminate is cut into a C-shaped shaping die (width 100 mm × length 800 mm × height 60 mm, corner R5 mm). , Longitudinal section: C type), vacuuming the space formed by the bagging film with the shaping mold and the bagging film with a vacuum pump, and pressurizing the laminate to the shaping mold And shaped.

  The laminated body is put into an oven in a state where it is pressed into a shaping mold, and heated at a temperature of 80 ° C. for 2 hours to join the reinforcing fiber bases of the laminated body, and then removed from the oven at room temperature. When a C-shaped preform was produced by cooling at a temperature, a wrinkle-free preform was obtained. When the reinforcing fiber volume fraction Vpf of the preform was measured, the Vpf was 53%.

(Example 2)
The preform produced in Example 1 was placed in a mold, an epoxy resin was injected, and vacuum bag molding was performed.
The injection of the epoxy resin was performed until the entire epoxy resin was impregnated with the epoxy resin. After the epoxy resin was discharged from the vacuum suction port, the injection port was closed and the injection of the epoxy resin was stopped. A vacuum suction line was connected to the inlet, and vacuum suction was performed together with the original vacuum suction port, and the epoxy resin that had been injected in excess was discharged.

  The discharge of the epoxy resin from the vacuum suction port prepared by connecting the original vacuum suction port and the injection port to the new vacuum suction line is performed by measuring the thickness of the preform impregnated with the epoxy resin, and the reinforcing fiber volume after molding. The process was performed until the rate Vf reached a thickness corresponding to 55%. The thickness of the preform impregnated with the epoxy resin was measured at three locations around the injection port and the vacuum suction port and at the center between the injection port and the vacuum suction port.

After discharging the epoxy resin, the epoxy resin impregnated in the preform was primarily cured at a temperature of 130 ° C. for 2 hours, and then secondarily cured at a temperature of 180 ° C. for 2 hours to form a vacuum bag.
When the reinforcing fiber volume fraction Vf of the obtained FRP was measured, Vf was 56%. Further, as a result of observing the surface appearance of the FRP, no remarkable wrinkles or fiber meandering was observed, and the surface quality was excellent.

(Comparative Example 1)
A laminated body of reinforced fiber base materials was obtained in the same manner as in Example 1 except that the pressure was applied with a joining jig in which the pitch of the pressure parts for pressing the end region was 20 mm. Here, a test piece having a width of 5 cm and a length of 15 cm was cut out from the end region of the laminated body, and the bonding force was measured. As a result, it was 300 N / m ^{2 From the} laminated body, 150 mm in the width direction and 1000 mm in the length direction. When it was cut out and placed on a C-shaped shaping mold, the end of the substrate was peeled off, and workability was poor.

(Comparative Example 2)
A laminated body of reinforcing fiber substrates was obtained in the same manner as in Example 1 except that the heating conditions were 95 ° C. and the pressing time was 15 minutes. Here, a test piece having a width of 5 cm and a length of 15 cm was cut out from the end region of the laminated body, and the bonding force was measured. As a result, it was 1200 N / m ^{2 From the} laminated body, 150 mm in the width direction and 1000 mm in the length direction. When a C-shaped preform was produced, a C-shaped preform with wrinkles was obtained.

(Example 3)
A reinforcing fiber substrate laminate (8ply [45/0 / −45 / 90] s, width 500 mm × length 5000 mm) is prepared using the reinforcing fiber substrate 1 of Example 1.

  (A) In the cutting step, the base material in the 45 ° direction, 90 ° direction, and −45 ° direction is cut with an automatic cutting machine. In the (B) lamination step, the cut base material 1 is cut using a robot arm. It was conveyed and arranged at a predetermined position on the conveyor 10. The 0 ° base material was directly arranged and laminated from the raw material roll 9 to prepare the above laminate (8ply [45/0 / −45 / 90] s, width 500 mm × length 5000 mm).

  (C) In the transport process, the laminate was transported to the heating process by a conveyor. In the heating step (D), the pressure bonding jig 21 having a function of generating heat with hot water was heated to 70 ± 5 ° C. without using an oven, and the laminate was directly heated. The laminate was efficiently heated by directly heating the laminate with the upper and lower bonding jigs.

(E) In the pressure bonding step, as shown in FIG. 7, the central portion 50 mm in the width direction is set as a high bonding region, the cross-sectional area of the pressure portion 24 corresponding to the region is 400 mm ² , and the cross-sectional shape is a 20 mm square rectangle. The shape was set, and the pitch was set to 30 mm in both the width direction and the length direction. Further, the pressurizing unit 24 corresponding to the low bonding region has a cross-sectional area of 4 mm ² , a 2 mm square shape, and a pitch of 10 mm in the width direction and 40 mm in the length direction.

The laminated body is pressurized for 5 minutes so that the pressure of one pressing part 24 is 0.05 MPa, and the reinforcing fiber bases 1 are partially bonded across the thickness direction by the adhesive resin on the surface of the reinforcing fiber base 1. Joined.
Thereafter, the laminate was allowed to stand at room temperature and cooled to obtain a laminate 2 of reinforcing fiber substrate. Here, in order to obtain the ratio of the high bonding area 5 of the laminate, ten test pieces having a width of 50 mm and a length of 150 mm were cut out from the laminate and the bonding force was measured. As a result, the high bonding area corresponding to the center portion was obtained. The bonding force of 900 was N / m ² , and the other nine bonding forces were less than 500 N / m ² (the ratio of the high bonding region between the laminated layers was 10%).

  Next, eight laminates having a width of 500 mm and a length of 600 mm are cut out from the laminate 2, and the eight laminates are formed into a C-shaped shaping die (width 300 mm × length 700 mm × height 150 mm, corner R10 mm, longitudinal Cross section in the direction: C type, longitudinal radius of curvature 2000 mm), and the space formed by the rubber sheet and the rubber sheet is vacuumed by a vacuum pump to form the laminate. Pressurized to form.

  Next, the laminate is put in an oven in a state where it is pressed into a shaping mold, and the laminate is heated at a temperature of 90 ° C. for 3 hours to join the laminates, then taken out of the oven and brought to room temperature. As a result, a C-type preform was produced, and a high-quality preform with no deviation in wrinkles and fiber orientation was obtained.

It is a perspective view which shows an example of the reinforced fiber base material laminated body of this invention. It is a perspective view which shows an example of the high joining area | region in the reinforced fiber base material laminated body of this invention. It is sectional drawing which shows an example of the reinforced fiber base material laminated body of this invention. It is the schematic which shows the manufacturing method of the reinforced fiber base-material laminated body of this invention. It is a schematic sectional drawing which shows the pressure bonding process in the manufacturing method of this invention. It is a schematic sectional drawing explaining the joining force measuring method in this invention. It is a schematic sectional drawing which shows the pressure bonding process in the manufacturing method of this invention. It is a figure used for description of the method of distinguishing the high joining area | region and low joining area | region of the reinforced fiber base material laminated body of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reinforcement fiber base material 2 Reinforcement fiber base material laminated body 3 Interlayer 4 Joint part 5 High joint area 6 Low joint area 7 Joint part 8 Resin 9 Robot arm 10 Conveyor 11 Hand apparatus 12 Roll 13 45 degree reinforcement fiber base material Automatic cutting machine 14 for cutting 14 45 ° reinforcing fiber substrate 15 Automatic cutting machine for cutting 90 ° reinforcing fiber substrate 16 90 ° reinforcing fiber substrate 17 Automatic cutting machine for cutting 45 ° reinforcing fiber substrate 18-45 ° Reinforcing Fiber Base 19 Slider 20 Oven 21 Pressure Bonding Jig 22 Bonding Jig Top 23 Bonding Jig Bottom 24 Pressure Unit 25 Winding Roll 26 Cooling Space 27 SUS Plate 28 Double-Sided Tape 29 Specimen 30 Base 31 Mounting jig 32 Longitudinal direction 33 Width direction 34 Test piece

Claims (9)

A planar reinforcing fiber substrate laminate formed by laminating a plurality of reinforcing fiber substrates, wherein joints are distributed over the entire surface between the laminated layers of the reinforcing fiber substrates, and the joints are formed by glass transition. temperature Tg has a resin containing a thermoplastic resin is adhered 2g / m ² ~40g / m ² is 0 ° C. to 95 ° C., and fused to the both reinforcing fiber substrates forming the laminated layers In addition, the stacked layers are formed from a high bonding region having a bonding force of 500 to 1000 N / m ² and a low bonding region in which the density of bonding portions is lower than that of the high bonding region. Reinforced fiber base laminate characterized by the above. The reinforcing fiber substrate laminate according to claim 1, wherein a ratio of the high bonding region between the laminated layers is 1 to 10%. The reinforcing fiber base laminate according to claim 1 or 2, wherein the high bonding region is a region having a width of 1 to 5 cm from an end of the reinforcing fiber base laminate. The reinforcing fiber substrate laminate according to any one of claims 1 to 3, wherein a bonding force between the layers in the high bonding region is 1.5 to 5 times as large as a bonding force between the layers in the low bonding region. A preform having a reinforcing fiber volume fraction Vpf of 40% to 62% obtained by shaping the reinforcing fiber substrate laminate according to any one of claims 1 to 4. The preform according to claim 5, wherein the preform is bonded to the entire surface between the reinforcing fiber base layers with a resin containing the thermoplastic resin. A fiber-reinforced plastic molded article having a reinforcing fiber volume fraction Vf in the range of 35% to 72% obtained by injecting, impregnating, and curing a matrix resin into the preform according to claim 5 or 6. Strengthening reinforcement on at least one surface of the fibrous substrate, a resin containing a thermoplastic resin having a glass transition temperature Tg of 0 ° C. to 95 ° C. is being deposited within the 2g / m ² ~40g / m ² A method for producing a reinforced fiber substrate laminate, comprising using a fiber substrate and producing a reinforced fiber substrate laminate through at least the following steps (A) to (F).
(A) A cutting step of cutting the reinforcing fiber base into a predetermined shape.
(B) A laminating process in which the reinforcing fiber base material cut into the predetermined shape is sequentially transported and arranged on a plane based on a predetermined laminating configuration.
(C) The conveyance process which conveys the laminated body obtained by (B) intermittently to a heating process.
(D) The heating process which heats the conveyed laminated body.
(E) The surface of the reinforcing fiber substrate is pressed using a pressing jig having a region where the area ratio of the pressing part having a high area per fixed area of the pressing jig is 1 to 10%. A pressure bonding step in which the reinforcing fiber bases of the pressure portion are bonded in the thickness direction with the resin containing the thermoplastic resin adhering to the surface.
(F) A cooling step for cooling the laminate. Pressurization in which the area ratio of the pressurizing unit per fixed area of the pressurizing jig pressurizing the end region having a width of 1 to 5 cm from the end of the reinforcing fiber base laminate presses other than the end region The method for producing a reinforced fiber base laminate according to claim 8, wherein the ratio is 1.5 to 5 times the area ratio of the pressing portion per fixed area of the jig.

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