JP4404080B2 - Manufacturing method of prepreg - Google Patents

Description

  The present invention relates to a method for producing a prepreg used for producing a laminated board.

  Conventionally, a prepreg is manufactured by impregnating a base material such as a glass nonwoven fabric with varnish, drying it, and then curing the resin in the base material to a semi-cured state (B stage state). In order to impregnate a base material with a varnish, generally, a construction method combining pre-impregnation and dipping (dipping) is employed. That is, after applying the varnish to one side of the substrate and pre-impregnating the varnish into the substrate from one side of the substrate, the substrate is immersed in the varnish, Impregnated with varnish. And by this pre-impregnation in this construction method, the air in the substrate can be pushed out from the other side where the varnish of the substrate is not applied, and thereby, the non-impregnated part of voids and varnishes A small number of prepregs can be formed.

However, even with a method that combines pre-impregnation and immersion, only prepregs with a large amount of voids or unimpregnated portions remaining inside the base material can be produced. Even if molded using this prepreg, There has been a problem that voids and scraps are generated in the laminated plate, resulting in molding defects. Therefore, as a method for improving the impregnation property of the varnish, as described in Patent Document 1, it is effective to impregnate the base material with the solvent before impregnating the base material with the varnish. Since the impregnation or the solvent must be dried, there is a problem that the productivity (production rate) of the prepreg is lowered and the cost is increased.
Japanese Patent Publication No. 7-55501

  The present invention has been made in view of the above points, and provides a method for producing a prepreg capable of producing a prepreg having almost no unimpregnated portions of voids and varnishes without lowering productivity or increasing costs. It is intended to provide.

The prepreg manufacturing method according to claim 1 of the present invention is a prepreg manufacturing method in which the base material 2 is impregnated with the varnish 1. The guide roll 16 is disposed above the varnish 1 stored in the flow generator tank 14. A reversing roll 15 is disposed in the varnish 1 stored in the flow generator tank 14, and a nozzle 4 for ejecting or sucking the varnish 1 is disposed between the guide roll 16 and the reversing roll 15. It arrange | positions so that it may face toward the single side | surface of the material 2, and arrange | positions the ejection suction port 17 of the nozzle 4 so that it may adjoin or contact the single side | surface of the base material 2, and it is the base material 2 between the guide roll 16 and the inversion roll 15. allowed to proceed at 2 to 20 m / min while immersed in varnish 1 viscosity 1～300Cps, ejecting the varnish 1 to the substrate 2 between the guide roller 16 and reversing roller 15 in the nozzle 4 or Suction or by flowing the varnish 1 Repeat these at a flow rate of 10 to 100 mm / sec, the substrate 2 outside the bubble B of passed through a varnish 1 in the base material 2 in the thickness direction to the substrate 2, the It is characterized by being extruded.

  The prepreg manufacturing method according to claim 2 of the present invention is the prepreg manufacturing method according to claim 1, wherein the reversing roll 15 is formed as a roll for generating the flow of the varnish 1, and remains on the base material 2 by the flow of the varnish 1. The air bubbles B are pushed out of the substrate 2.

  According to the first aspect of the present invention, a guide roll is disposed above the varnish stored in the flow generator tank, and a reversing roll is disposed in the varnish stored in the flow generator tank. By immersing the substrate in the varnish between the rolls and jetting or sucking the varnish to the substrate between the guide roll and the reversing roll with a nozzle, or by repeating these to flow the varnish Since the varnish is passed through the base material in the thickness direction and the bubbles in the base material are pushed out of the base material, the air bubbles in the base material can be removed, so that there is almost no void or varnish unimpregnated part. Is something that can be done. Moreover, since no unnecessary solvent is used in the prepreg for removing bubbles in the base material, the prepreg is not impregnated with the solvent or dried, so that the productivity is not lowered and the cost is not increased. Is. In addition, the varnish is jetted or sucked against the base material, or these are repeated to cause the varnish to flow, so that air bubbles in the base material can be removed by the flow of the varnish, and there are almost no unimpregnated portions of voids and varnish. There is something that can be done.

  Hereinafter, the best mode for carrying out the present invention will be described.

  FIG. 1 shows an example of an apparatus used in the prepreg manufacturing method of the present invention. The manufacturing apparatus includes a pre-impregnation machine 10, a varnish flow generator 3, and an immersion machine (dip machine) 20.

  The pre-impregnating machine 10 is arranged above the pre-impregnating machine tank 11, a pre-impregnating machine tank 11 for storing the pre-impregnating varnish 1, an application roll (kiss roll) 12 disposed in the pre-impregnating machine tank 11, and the pre-impregnating machine tank 11. And a pair of transport rolls 13. The coating roll 12 and the transport roll 13 are formed so as to be freely rotatable by a drive device such as a motor with a direction orthogonal to the transport direction of the substrate 2 described later as a rotation axis. Moreover, the lower half of the coating roll 12 is immersed in the varnish 1 stored in the pre-impregnation machine tank 11. Further, the application roll 12 is disposed between the pair of transport rolls 13 and below the transport roll 13.

  The varnish flow generator 3 includes a flow generator tank 14 for storing the flow varnish 1, a reversing roll 15 disposed in the flow generator tank 14, and a pair of guides disposed above the flow generator tank 14. A roll 16 and a nozzle 4 arranged in the flow generator tank 14 are provided. The reversing roll 15 and the guide roll 16 are formed so as to be rotatable and driven by a driving device such as a motor with a direction orthogonal to the conveyance direction of the substrate 2 described later as a rotation axis. Further, the entire reverse roll 15 is immersed in the varnish 1 stored in the flow generator tank 14. The reverse roll 15 is disposed between the pair of guide rolls 16 and below the guide rolls 16. The nozzle 4 is entirely immersed in the varnish 1 stored in the fluid generator tank 14, and a jet suction port 17 for jetting and sucking the varnish 1 is provided in the nozzle 4. Further, a pump or the like serving as a drive source for ejecting or sucking the varnish 1 from the ejection suction port 17 of the nozzle 4 is connected to the nozzle 4 via a connection pipe 18.

  The dipping machine 20 has a dipping machine tank 21 for storing the varnish 1 for dipping, a dip roll 22 arranged in the dipping machine tank 21, and a pair of removal rolls arranged above the dipping machine tank 21 and the dip roll 22. 23. The dip roll 22 and the removal roll 23 are formed so as to be freely rotatable by a driving device such as a motor with a direction orthogonal to the conveyance direction of the substrate 2 described later as a rotation axis. Further, the dip roll 22 is entirely immersed in the varnish 1 stored in the immersion machine tank 21.

As said varnish 1, what was conventionally used for manufacture of a prepreg can be used as it is, for example, thermosetting resins, such as an epoxy resin and a melamine resin, methyl ethyl ketone (MEK), dimethylformamide (DMF), etc. The varnish 1 can be prepared by dissolving in a solvent. Viscosity of the varnish 1 1～300Cps, resin concentration can be set respectively to 50 to 70 mass%. Moreover, the same thing may be used as the varnish 1 for pre-impregnation, the varnish 1 for a flow, and the varnish 1 for immersion, and the thing from which a viscosity, resin concentration, and the kind of resin differ may be used. The varnish 1 (particularly the varnish 1 for flow) is preferably defoamed before being supplied to the substrate 2. The defoaming method can be performed, for example, by putting varnish into a tank whose internal pressure is evacuated. By defoaming the varnish 1 in this manner, the bubbles in the varnish 1 are not supplied to the base material 2, and the occurrence of voids and unimpregnated portions of the varnish 1 in the prepreg is reduced. It is something that can be done.

The base material 2 used in the present invention is formed in a long shape, and those conventionally used for the production of prepregs can be used as they are, for example, glass nonwoven fabric, glass woven fabric, polyester fiber, Nonwoven fabrics and woven fabrics using synthetic fibers such as polyamide fibers can be used. Further, the thickness and basis weight of the base material 2 are not particularly limited, but in order to make it easier to remove the bubbles B from the base material 2, the thickness of the base material 2 is 0.06 to 0.20 mm, and the basis weight is 28. It is preferable to set each to ˜120 g / m ² .

  When the base material 2 is impregnated with the varnish 1 using the above-described prepreg manufacturing apparatus, it is performed as follows. First, the base material 2 is set as shown in FIG. 1 so that the long base material 2 continuously passes through the pre-impregnation machine 10, the varnish flow generator 3 and the dipping machine 20 in this order. To do. When the base material 2 is set in this manner, in the pre-impregnation machine 10, the upper surface (surface) of the base material 2 is in contact with the lower peripheral surface of the pair of transport rolls 13, and the upper peripheral surface of the coating roll 12 is the base material 2, and the lower surface of the substrate 2 is in contact with the upper peripheral surface of the pair of guide rolls 16 and the lower peripheral surface of the reversing roll 15. In addition, in the dipping machine 20, the upper surface of the substrate 2 contacts the lower peripheral surface of the dip roll 22, and the substrate 2 passes between the pair of removal rolls 23. It will be in the state. Further, in the varnish flow generator 3, the nozzle 4 is arranged so that the ejection suction port 17 faces the base material 2. That is, the nozzle 4 is arranged so that the ejection suction port 17 faces the one surface (back surface) of the substrate 2 between the one (introduction side) guide roll 16 and the reverse roll 15. In addition, the nozzle 4 is arranged such that its ejection suction port 17 is close to or in contact with one surface of the base material 2.

  And while maintaining the state which set the base material 2 as mentioned above, the conveyance roll 13, the application | coating roll 12, the guide roll 16, the reverse roll 15, the dip roll 22, and the removal roll 23 are rotationally driven, and it is long. The base material 2 is continuously advanced in the longitudinal direction, and the base material 2 is impregnated with the varnish 1.

  That is, first, the base material 2 is pre-impregnated with the varnish 1 by the pre-impregnation machine 10. In the pre-impregnation, the upper surface of the coating roll 12 is brought into contact with the lower surface of the base material 2 to apply the varnish 1 attached to the peripheral surface of the coating roll 12 to the lower surface of the base material 2. The upper surface is impregnated with the varnish 1, whereby the air in the base material 2 is pushed by the impregnation of the varnish 1 and moves from the lower surface side to the upper surface side of the base material 2. It is pushed out of the substrate 2 and discharged.

  Next, the pre-impregnated base material 2 is introduced into the varnish flow generator 3, where air bubbles (voids) B remaining between the fibers of the base material 2 are pushed out of the base material 2 by the flow of the varnish 1. And remove it. That is, air cannot be sufficiently removed from the base material 2 only by pre-impregnation, and air remains as a large number of bubbles B in the pre-impregnated base material 2 as shown in FIG. . Therefore, in the present invention, in the varnish flow generator 3 as shown by an arrow in FIG. 2 (b), by flowing the varnish 1 so that the varnish 1 passes through the substrate 2 in the thickness direction (front and back direction), The bubbles B in the substrate 2 are forced out of the substrate 2 by the flow of the varnish 1, and the varnish 1 is forcibly supplied into the substrate 2 to be impregnated. ), It is possible to prevent bubbles from being present in the substrate 2. In the embodiment shown in FIG. 1, the varnish 1 is continuously ejected from the ejection suction port 17 of the nozzle 4 toward the substrate 2, or the varnish 1 is continuously suctioned from the ejection suction port 17 of the nozzle 4. Alternatively, the flow of the varnish 1 is generated by oscillating the varnish 1 by alternately repeating and continuously ejecting and sucking the varnish 1 from the ejection suction port 17 of the nozzle 4. At this time, the flow rate of the varnish 1 varies depending on the traveling speed of the base material 2 and the like, but when the traveling speed of the base material 2 is 2 m / min, the flow speed of the varnish 1 is preferably 10 mm / second or more. In addition, since the advancing speed of the base material 2 is 2-20 m / min normally, the flow rate of the varnish 1 can be set to 10-100 mm / sec.

  Next, the base material 2 from which the bubbles B have been almost removed by the varnish flow generator 3 is introduced into the immersion machine 20 where the base material 2 is immersed in the varnish 1. As described above, almost no bubbles B remain in the substrate 2, but the bubbles B are more completely removed from the substrate 2 by immersing the substrate 2 in the varnish 1 with the dipping machine 20. Further, since the varnish 1 is unevenly distributed in the substrate 2 due to the flow of the varnish 1 in the varnish flow generator 3, an unimpregnated portion of the varnish 1 may be generated. The base material 2 is uniformly impregnated with the varnish 1 by dipping. And after the base material 2 is immersed in the varnish 1, it will be pulled up through between a pair of removal rolls 23, When the removal roll 23 contacts between both surfaces of the base material 2 when passing between a pair of removal rolls 23, it is. Yes, thereby removing the excess varnish 1 adhering to both surfaces of the substrate 2.

  In this way, the base material 2 impregnated with the varnish 1 is dried by the pre-impregnation machine 10, the varnish flow generator 3 and the dipping machine 20, and then the resin in the base material 2 is cured to a semi-cured state by heating or the like. By doing so, a prepreg can be formed. This prepreg is formed by forcibly extruding and removing the bubbles B in the base material 2 out of the base material 2 by the flow of the varnish 1, so that there is almost no void or varnish unimpregnated portion. is there. Moreover, since the prepreg is impregnated with the varnish 1 necessary for removing the air bubbles B in the substrate 2, the prepreg is impregnated with an unnecessary solvent as in the prior art. And the solvent is not dried, and the productivity is not lowered and the cost is not increased.

  FIG. 3 shows a reference example. In this prepreg manufacturing apparatus, the pre-impregnation machine 10 and the dipping machine 20 are formed in the same manner as described above, and the varnish flow generator 3 is formed of a different one from the above. That is, the varnish flow generator 3 does not include the nozzle 4, but as shown in FIG. 4, the flow generator tank 14 for storing the flow varnish 1 and the reversing roll disposed in the flow generator tank 14. 15 and a pair of guide rolls 16 disposed above the flow generator tank 14. The reversing roll 15 and the guide roll 16 are formed so as to be rotatable and driven with a direction orthogonal to the conveyance direction of the substrate 2 described later as a rotation axis. Further, the entire reverse roll 15 is immersed in the varnish 1 stored in the flow generator tank 14. The reverse roll 15 is disposed between the pair of guide rolls 16 and below the guide rolls 16. And this inversion roll 15 is a vibration apparatus, Comprising: It forms as the roll 5 for vibrating a varnish and making it flow.

  As shown in FIGS. 5 (a) and 5 (b), the reversing roll 15 includes a vibration generating rotating body 30 having an uneven surface and an inner cylinder 32 provided with a large number of small holes 31 over the entire surface. And an outer cylindrical body 34 provided with a large number of large holes 33 over the entire surface. The small hole 31 is formed so as to penetrate the inner cylinder 32, and the large hole 33 is formed so as to penetrate the outer cylinder 34. And the inversion roll 15 is formed by inserting and arrange | positioning the inner side cylinder 32 inside the outer side cylinder 34, and inserting and arrange | positioning the vibration generation | occurrence | production rotary body 30 inside the inner side cylinder 32, thereby. The substrate contact surface of the reversing roll 15 (the outer peripheral surface of the reversing roll 15) is formed in a porous structure. The vibration generating rotator 30, the inner cylinder 32, and the outer cylinder 34 are formed to be rotatable with respect to each other. Further, the vibration generating rotator 30, the inner cylinder 32, and the outer cylinder 34 are formed so as to be freely rotatable by a driving device such as a motor with a direction orthogonal to the conveying direction of the substrate 2 as a rotation axis. The generating rotator 30 is set to rotate in the opposite direction to the inner cylinder 32 and the outer cylinder 34. That is, the inner cylindrical body 32 and the outer cylindrical body 34 are rotationally driven so that the lower part thereof is in the same direction as the traveling direction of the substrate 2, and the vibration generating rotator 30 has a lower part opposite to the traveling direction of the substrate 2. It is rotationally driven so that

  When the base material 2 is impregnated with the varnish 1 using such a prepreg manufacturing apparatus, it is performed as follows. First, the long base material 2 is set in the pre-impregnation machine 10, the varnish flow generator 3, and the dipping machine 20 in the same manner as described above shown in FIG. 1. Next, while maintaining the state in which the base material 2 is set as described above, the transport roll 13, the coating roll 12, the guide roll 16, the reverse roll 15, the dip roll 22, and the removal roll 23 are rotationally driven, thereby increasing the length. The scale substrate 2 is continuously advanced in the longitudinal direction thereof, and the substrate 2 is impregnated with the varnish 1.

  That is, first, the base material 2 is pre-impregnated with the varnish 1 by the pre-impregnation machine 10 as described above. Next, the pre-impregnated base material 2 is introduced into the varnish flow generator 3, and air bubbles (voids) B remaining on the base material 2 due to the flow of the varnish 1 are moved out of the base material 2 as described above. Extrude and remove. In the reference example shown in FIG. 3, by rotating the vibration generating rotator 30 of the reversing roll 15, the varnish 1 continuously vibrates and the varnish 1 passes through the base material 2 in the thickness direction (front and back direction). Thus, the varnish 1 is made to flow. That is, when the vibration generating rotator 30 is rotated with respect to the inner cylinder 32 and the outer cylinder 34, the varnish 1 that has flowed into the inner cylinder 32 by the action of the irregular shape on the peripheral surface of the vibration generating rotator 30 is illustrated in FIG. 5 (b), as indicated by an arrow, is continuously ejected from the reversing roll 15 through the small hole 31 and the large hole 33, sucked into the reversing roll 15, or repeatedly ejected and sucked. Thereby, the varnish 1 is continuously vibrated to generate a flow of the varnish 1. Then, the flow of the varnish 1 causes the same action as shown in FIGS. 2A to 2C, and the bubbles B remaining on the base material 2 can be pushed out of the base material 2 and removed. Is. The frequency of vibration of the varnish 1 varies depending on the traveling speed of the base material 2 and the like, but when the traveling speed of the base material 2 is 2 m / min, the frequency of vibration of the varnish 1 is preferably 80 to 120 Hz. In addition, since the advancing speed of the base material 2 is 2-20 m / min normally, the frequency of the vibration of the varnish 1 can be set to 80-1200 Hz. Further, the outer cylinder 34 may have the same rotational speed as the traveling speed of the base material 2, or may have a different rotational speed. The different rotational speeds cause the base material 33 to move as the position of the large hole 33 progresses. 2 can be changed, which is preferable because the varnish 1 can be uniformly impregnated into the substrate 2.

  Next, the base material 2 from which the bubbles B have been almost removed by the varnish flow generator 3 is introduced into the immersion machine 20, where the base material 2 is immersed in the varnish 1 in the same manner as described above. Then, after drying the base material 2 in the same manner as described above, the prepreg can be formed by curing the resin in the base material 2 to a semi-cured state by heating or the like. And also in this prepreg, it is formed by forcibly extruding and removing the bubbles B in the base material 2 out of the base material 2 by the flow of the varnish 1, so that there is almost no void or varnish unimpregnated portion. It is. Moreover, since the prepreg is impregnated with the varnish 1 necessary for removing the bubbles B in the base material 2, the prepreg is impregnated with an unnecessary solvent as in the prior art. And the solvent is not dried, and the productivity is not lowered and the cost is not increased.

  In the reference example shown in FIG. 3, only the varnish 1 is ejected from the reversing roll 15 through the varnish supply ports connected to both ends of the inner cylinder 32 of the reversing roll 15 or only the varnish 1 is sucked into the reversing roll 15. This allows the varnish 1 to flow so that the varnish 1 passes through the substrate 2 in the thickness direction (front and back direction) by ejecting or sucking the varnish 1 with respect to the substrate 2. A reversing roll 15 can be formed as the roll 5. In this case, as shown in FIGS. 6 and 7A and 7B, the reversing roll 15 has an inner cylindrical body 32 provided with a large number of small holes 31 on the substantially lower half surface and a large number of large holes 33. The outer cylindrical body 34 provided over the entire surface is provided. The small hole 31 is formed so as to penetrate the inner cylinder 32, and the large hole 33 is formed so as to penetrate the outer cylinder 34. And the inversion roll 15 is formed by inserting and arrange | positioning the inner side cylinder 32 inside the outer side cylinder 34, Thereby, the base-material contact surface (outer peripheral surface of the inversion roll 15) of the inversion roll 15 is formed. It is formed in a porous structure. In the reversing roll 15, the inner cylinder 32 is fixed and only the outer cylinder 34 is rotated. Furthermore, varnish supply ports 40 communicating with the inside of the inner cylinder 32 are provided at both ends of the inner cylinder 32.

  In such a reversing roll 15, the varnish 1 is supplied from the varnish supply port 40 to the inside of the inner cylinder 32 using a pump or the like, and the varnish 1 supplied to the inside of the inner cylinder 32 is supplied to the small holes 31 and the outer cylinder. By ejecting through the 34 large holes 33, the varnish 1 can be caused to flow so that the varnish 1 passes through the substrate 2 in the thickness direction (front and back direction). In the reversing roll 15, the varnish 1 is sucked from the varnish supply port 40 to the inside of the inner cylinder 32 using a pump or the like, so that the varnish 1 passes through the small hole 31 and the large hole 33 of the outer cylinder 34. By sucking the varnish 1 into the body 32, the varnish 1 can be flowed so that the varnish 1 passes through the substrate 2 in the thickness direction (front and back direction). Then, the flow of the varnish 1 causes the same action as shown in FIGS. 2A to 2C, and the bubbles B remaining on the base material 2 can be pushed out of the base material 2 and removed. Is. The outer cylinder 34 may have the same rotational speed as the traveling speed of the base material 2 or may have a different rotational speed. The different rotational speeds cause the base material 33 to move as the position of the large hole 33 progresses. 2 can be changed, which is preferable because the varnish 1 can be uniformly impregnated into the substrate 2. Moreover, in the inversion roll 15 shown in FIG.6 and FIG.7 (a) (b), the flow of said varnish 1 is made to vibrate by oscillating the varnish 1 by alternately repeating and ejecting the varnish 1 continuously. It may be generated.

  FIG. 8 shows another embodiment. This prepreg manufacturing apparatus uses the varnish flow generator 3 shown in FIG. 1 using the reversing roll 15 formed as the vibration device of FIG. 3, and other configurations are the other embodiments and reference. It is formed in the same way as the example. In this prepreg manufacturing apparatus, the flow of the varnish 1 is generated by both the nozzle 4 and the reverse roll 15.

  And compared with the manufacture of the conventional prepreg using only the pre-impregnation machine 10 and the immersion machine 20, in this invention, the area of the non-impregnation part of the void and the varnish 1 was able to be reduced by 80%.

It is the schematic which shows an example of the manufacturing apparatus used by embodiment of this invention. The base material same as the above is shown, and (a) to (c) are schematic cross-sectional views. It is the schematic which shows an example of the manufacturing apparatus of a reference example same as the above. It is the schematic which shows an example of a varnish flow generator same as the above. (A) is a perspective view in which a part of the reversing roll is partially broken, and (b) is an enlarged sectional view of a part. It is the schematic which shows the other example of a varnish flow generator same as the above. (A) is a perspective view in which a part of the reversing roll is partially broken, and (b) is a partially enlarged sectional view. It is the schematic which shows an example of the manufacturing apparatus used by other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Varnish 2 Base material 3 Varnish flow generator 4 Nozzle 5 Roll 14 Flow generator tank 15 Inversion roll 16 Guide roll 17 Ejection suction port B Bubble

Claims (2)

In a method for producing a prepreg in which a base material is impregnated with a varnish, a guide roll is disposed above the varnish stored in the flow generator tank, and a reverse roll is disposed in the varnish stored in the flow generator tank. The nozzle for jetting or sucking the nozzle is arranged so that the jet suction port faces the one side of the substrate between the guide roll and the reverse roll, and the nozzle jet suction port is close to or in contact with one side of the substrate. The substrate is moved at a rate of 2 to 20 m / min while being immersed in a varnish having a viscosity of 1 to 300 cps between the guide roll and the reverse roll. varnish was ejected or sucked by a nozzle, or by flowing in the varnish Repeat these flow rate 10 to 100 mm / sec, varnishes its thickness direction to the substrate Method for producing a prepreg, characterized by extruding by passing air bubbles in the substrate outside the substrate. 2. The method for producing a prepreg according to claim 1, wherein the reversing roll is formed as a roll for generating a flow of varnish, and air bubbles remaining on the base material are pushed out of the base material by the flow of the varnish. .

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