JP2012046635A - Method for manufacturing prepreg and apparatus for manufacturing prepreg - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing prepreg which reduces a void or an unimpregnated portion remaining inside the prepreg than ever before without reduction of productivity and cost rise.SOLUTION: There is provided the method for manufacturing prepreg by impregnating a varnish 4 in a base material 3 which is woven with warp yarns 1 and weft yarns 2 then by drying the varnish. The varnish 4 is impregnated into the base material 3 by being contacted to the base material 3 so as to avoid the varnish being parallelled with either the warp yarns 1 or the weft yarns 2.

Description

  The present invention relates to a method for producing a prepreg used as a material for a printed wiring board or the like, and an apparatus for producing a prepreg.

  Conventionally, a prepreg used as a material for a printed wiring board or the like is manufactured by impregnating a base material such as a glass cloth with a varnish and then drying it to make it a semi-cured state (B stage state). And when impregnating a base material with a varnish, the construction method which combined pre-impregnation and immersion (dipping) is generally employ | adopted. That is, in this construction method, varnish is applied to one side of the base material, pre-impregnation is performed by impregnating the varnish into the base material from one side of the base material, and then the base material is immersed in the varnish. The base material is impregnated with varnish.

  However, in the construction method that combines pre-impregnation and immersion, a lot of voids and unimpregnated portions remain inside the prepreg, so voids and the like also remain inside printed wiring boards manufactured using such a prepreg. There is a problem.

  Therefore, as a method for improving the impregnating property of the varnish, a method of impregnating the varnish after impregnating the base material with a solvent has been developed (for example, see Patent Document 1).

  However, in the above-mentioned construction method, the solvent must be degassed in advance or the base material must be impregnated with only the solvent in advance, leading to a decrease in prepreg productivity (production speed) and an increase in cost. There's a problem.

Japanese Patent Publication No. 7-55501

  The present invention has been made in view of the above points, and is a prepreg capable of reducing voids remaining in the prepreg and non-impregnated portions as compared with conventional prepregs without lowering productivity or increasing costs. An object of the present invention is to provide a manufacturing method and a prepreg manufacturing apparatus.

  In the prepreg manufacturing method according to the present invention, when a prepreg is manufactured by impregnating a base material woven with warp and weft and then drying the varnish, neither the warp nor the weft is parallel. Thus, the varnish is brought into contact with the base material and impregnated.

  The apparatus for producing a prepreg according to the present invention produces a prepreg by impregnating a varnish into a base material while conveying the long base material woven with warp and weft in the longitudinal direction, and then drying the base material. The apparatus further comprises a curtain coating device formed by providing a nozzle for flowing down the varnish in a curtain shape, and the curtain coating device causes the curtain shape from the nozzle so that neither the warp yarn nor the weft yarn is parallel. The varnish flowing down is brought into contact with the substrate and impregnated.

  The apparatus for producing a prepreg according to the present invention produces a prepreg by impregnating a varnish into a base material while conveying the long base material woven with warp and weft in the longitudinal direction, and then drying the base material. The apparatus comprises a roll coating device formed by providing a roll to which the varnish is supplied to the outer peripheral surface, and the roll coating device allows the outer periphery of the roll to be in parallel with neither the warp yarn nor the weft yarn. The varnish supplied to the surface is brought into contact with the substrate and impregnated.

  The apparatus for producing a prepreg according to the present invention produces a prepreg by impregnating a varnish into a base material while conveying the long base material woven with warp and weft in the longitudinal direction, and then drying the base material. The apparatus includes a die coating device formed by providing a slit-shaped nozzle for discharging the varnish, and the slit-shaped nozzle is prevented from being parallel to either the warp or the weft by the die coating device. The varnish discharged from is brought into contact with the substrate and impregnated.

  According to the present invention, by contacting and impregnating the base material so that the varnish is not parallel to either the warp or the weft, the varnish penetrates in the fiber direction by capillary action for both the warp and the weft, and the warp and Air in the fiber of the weft can be pushed out to the outside, and the voids remaining in the interior of the prepreg and the unimpregnated portion can be reduced more than before without lowering the productivity or increasing the cost. .

It is a schematic perspective view which shows an example of the manufacturing apparatus of the prepreg which concerns on this invention. It is a schematic perspective view which shows another example of the manufacturing apparatus of the prepreg which concerns on this invention. It is a schematic perspective view which shows another example of the manufacturing apparatus of the prepreg which concerns on this invention. (A) is explanatory drawing which shows a mode that a varnish contacts and impregnates a base material so that neither a warp nor a weft is parallel, (b) is so that a varnish becomes perpendicular | vertical to a warp and becomes parallel with a weft It is explanatory drawing which shows a mode that it contacts and impregnates a base material.

  Embodiments of the present invention will be described below.

  FIG. 1 shows an example of a prepreg manufacturing apparatus according to the present invention. This prepreg manufacturing apparatus includes a curtain coating apparatus 6 (curtain coater), a dip pan 11, and a dryer (not shown). It is formed in preparation. In addition, although the dip pan 11 may not be provided, what provided the dip pan 11 is demonstrated below.

  The curtain coating apparatus 6 impregnates the base material 3 with the varnish 4, and is formed by providing a nozzle 5 that flows down the varnish 4 in a curtain shape. Although the flow rate of the varnish 4 is not specifically limited, For example, it is preferable that it is 10-100 mm / sec.

  Here, as the base material 3, as shown in FIG. 4, the long thing woven with the warp 1 and the weft 2 is used. The warp 1 and the weft 2 may be formed with inorganic fibers such as glass fibers, or may be formed with organic fibers such as aramid fibers. Therefore, as the base material 3, for example, a glass cloth (glass woven fabric) or an aramid woven fabric can be used. Moreover, the weaving method of the base material 3 is not particularly limited, and may be plain weave or twill weave. The warp 1 of the base 3 is parallel to the longitudinal direction of the base 3, and the weft 2 of the base 3 is parallel to the width of the base 3.

  As the varnish 4, the same varnish can be used. For example, the varnish 4 can be prepared by dissolving a thermosetting resin such as an epoxy resin or a melamine resin in a solvent such as methyl ethyl ketone (MEK) or dimethylformamide (DMF). Although the viscosity of the varnish 4 is not specifically limited, For example, it is preferable that it is 0.1-100 mPa * s.

  The long base 3 is transported in the longitudinal direction under the nozzle 5 of the curtain coating apparatus 6, but the curtain is arranged in the bias direction so that the width direction of the base 3 and the nozzle 5 do not become parallel. A coating device 6 is installed. Of course, the longitudinal direction of the substrate 3 and the nozzle 5 are not parallel. At this time, the angle θ formed by the straight line 12 in the width direction of the substrate 3 and the straight line 13 formed by projecting the nozzle 5 onto the substrate 3 in the vertical direction is preferably 10 to 70 °, and 40 More preferably, it is ˜50 °.

  The dip pan 11 is for impregnating the base material 3 impregnated with the varnish 4 with the curtain coating device 6 again, and is formed by opening the upper surface and providing the guide roll 14 therein. The varnish 4 is stored inside the dip pan 11 so that the guide roll 14 sinks. This varnish 4 may be the same as or different from the varnish 4 flowing down from the nozzle 5 of the curtain coating apparatus 6.

  Moreover, a dryer will not be specifically limited if the base material 3 which the varnish 4 was impregnated with the dip pan 11 is heated and dried at the temperature of 100-240 degreeC, for example.

  The prepreg can be manufactured as follows using the prepreg manufacturing apparatus shown in FIG.

  First, the base material 3 is impregnated with the varnish 4 by the curtain coating device 6 while the long base material 3 is conveyed in the longitudinal direction at a speed of, for example, 1 to 20 m / min. At this time, the varnish 4 flowing in a curtain form from the nozzle 5 of the curtain coating device 6 contacts the base material 3 so as not to be parallel to either the warp 1 or the weft 2 as shown in FIG. Impregnation. Then, in both the warp 1 and the weft 2, the varnish 4 penetrates in the fiber direction (the arrow direction in FIG. 4A) by the capillary phenomenon and pushes the air 15 in the fibers of the warp 1 and the weft 2 to the outside. It can be done. On the other hand, as shown in FIG. 4B, when the varnish 4 is in contact with the base material 3 so as to be parallel to the weft 2, the varnish 4 is in the fiber direction (FIG. The air 15 in the fibers of the warp 1 can be pushed out by penetrating in the direction of arrow b). However, as for the weft yarn 2, the varnish 4 does not penetrate in the fiber direction and traps the air 15 in the fiber of the weft yarn 2 as it is, which remains inside the prepreg as voids or unimpregnated portions.

  Then, as shown in FIG. 1, the base material 3 is impregnated with the varnish 4 by the curtain coating device 6, and then the base material 3 is immersed in the varnish 4 of the dip pan 11 so that the varnish 4 is again applied to the base material 3. Impregnate. Prior to this impregnation, the air 15 in the fibers of the base material 3 has already been pushed out, so even if the base material 3 is impregnated with the varnish 4 again by the dip pan 11, voids or non-impregnated inside the prepreg The part is difficult to remain.

  After that, the prepreg is continuously changed by changing the direction with the guide roll 14 and heating and drying the base material 3 coming out of the varnish 4 of the dip pan 11 by a drier to make a semi-cured state (B stage state). Can be manufactured. As described above, according to the prepreg manufacturing apparatus shown in FIG. 1, since it is not necessary to previously depressurize the solvent under reduced pressure or impregnate the base material 3 with only the solvent in advance, the productivity can be improved. The voids and unimpregnated portions remaining inside the prepreg can be reduced as compared with the prior art without lowering and cost increase.

  FIG. 2 shows another example of the prepreg manufacturing apparatus according to the present invention. The prepreg manufacturing apparatus includes a roll coating apparatus 8 (roll coater), a dip pan 11, and a dryer (not shown). And is formed. In addition, although the dip pan 11 may not be provided, what provided the dip pan 11 is demonstrated below.

The roll coating apparatus 8 impregnates the base material 3 with the varnish 4 and is formed by providing a roll 7 to which the varnish 4 is supplied to the outer peripheral surface. The method for supplying the varnish 4 to the outer peripheral surface of the roll 7 is not particularly limited, but the coating amount of the varnish 4 on the substrate 3 is preferably ¹ to 100 mL / m ² .

  Here, as the substrate 3 and the varnish 4, those described above can be used.

  And although the elongate base material 3 is conveyed in a longitudinal direction so that the roll 7 of the roll coating apparatus 8 may contact, the width direction of the base material 3 and the rotating shaft of the roll 7 are not parallel, That is, the roll coating apparatus 8 is installed in the bias direction. Of course, the longitudinal direction of the substrate 3 and the rotation axis of the roll 7 are not parallel. At this time, the angle θ formed by the straight line 12 in the width direction of the substrate 3 and the ridge line 16 of the roll 7 in contact with the substrate 3 is preferably 10 to 70 °, and more preferably 40 to 50 °. preferable.

  As the dip pan 11 and the dryer, those described above can be used.

  The prepreg can be manufactured as follows using the prepreg manufacturing apparatus shown in FIG.

  First, the base material 3 is impregnated with the varnish 4 by the roll coating device 8 while transporting the long base material 3 in the longitudinal direction at a speed of 1 to 20 m / min, for example. At this time, the varnish 4 supplied to the outer peripheral surface of the roll 7 of the roll coating apparatus 8 contacts the base material 3 so as not to be parallel to either the warp 1 or the weft 2 as shown in FIG. Impregnation. Then, in both the warp 1 and the weft 2, the varnish 4 penetrates in the fiber direction (the arrow direction in FIG. 4A) by the capillary phenomenon and pushes the air 15 in the fibers of the warp 1 and the weft 2 to the outside. It can be done. On the other hand, as shown in FIG. 4B, when the varnish 4 is in contact with the base material 3 so as to be parallel to the weft 2, the varnish 4 is in the fiber direction (FIG. The air 15 in the fibers of the warp 1 can be pushed out by penetrating in the direction of arrow b). However, as for the weft yarn 2, the varnish 4 does not penetrate in the fiber direction and traps the air 15 in the fiber of the weft yarn 2 as it is, which remains inside the prepreg as voids or unimpregnated portions.

  And after making the base material 3 impregnate the base material 3 with the roll coating apparatus 8 as shown in FIG. 2, this base material 3 is immersed in the varnish 4 of the dip pan 11, and the varnish 4 is made into the base material 3 again. Impregnate. Prior to this impregnation, the air 15 in the fibers of the base material 3 has already been pushed out, so even if the base material 3 is impregnated with the varnish 4 again by the dip pan 11, voids or non-impregnated inside the prepreg The part is difficult to remain.

  After that, the prepreg is continuously changed by changing the direction with the guide roll 14 and heating and drying the base material 3 coming out of the varnish 4 of the dip pan 11 by a drier to make a semi-cured state (B stage state). Can be manufactured. As described above, according to the prepreg manufacturing apparatus shown in FIG. 2, it is not necessary to preliminarily depressurize the solvent in advance or impregnate the base material 3 with only the solvent in the conventional manner. The voids and unimpregnated portions remaining inside the prepreg can be reduced as compared with the prior art without lowering and cost increase.

  FIG. 3 shows another example of the prepreg manufacturing apparatus according to the present invention. This prepreg manufacturing apparatus includes a die coating apparatus 10 (die coater) and a dryer (not shown). Has been.

The die coating apparatus 10 impregnates the base material 3 with the varnish 4 and is formed by providing a slit-like nozzle 9 for discharging the varnish 4. Although the application quantity to the base material 3 of the varnish 4 is not specifically limited, For example, it is preferable that it is 1-100 mL / m < ² >.

  Here, as the substrate 3 and the varnish 4, those described above can be used.

  And the elongate base material 3 is conveyed in a longitudinal direction so as to oppose the nozzle 9 of the die coating apparatus 10, but the width direction of the base material 3 and the nozzle 9 are not parallel, that is, the bias direction. The die coating apparatus 10 is installed in the above. Of course, the longitudinal direction of the base material 3 and the nozzle 9 are not parallel. At this time, the angle θ formed by the straight line 12 in the width direction of the substrate 3 and the straight line 17 formed by projecting the nozzle 9 onto the substrate 3 in the vertical direction is preferably 10 to 70 °, More preferably, it is ˜50 °.

  As the dip pan 11 and the dryer, those described above can be used.

  The prepreg can be manufactured as follows using the prepreg manufacturing apparatus shown in FIG.

  First, the varnish is applied to the base material 3 by the die coating apparatus 10 while transporting the long base material 3 in the longitudinal direction at a speed of 1 to 20 m / min by changing the direction of the long base material 3 with a guide roll 14 as necessary. 4 is impregnated. At this time, the varnish 4 discharged from the slit-like nozzle 9 of the die coating apparatus 10 contacts the base material 3 so as not to be parallel to either the warp 1 or the weft 2 as shown in FIG. Impregnation. Then, in both the warp 1 and the weft 2, the varnish 4 penetrates in the fiber direction (the arrow direction in FIG. 4A) by the capillary phenomenon and pushes the air 15 in the fibers of the warp 1 and the weft 2 to the outside. It can be done. On the other hand, as shown in FIG. 4B, when the varnish 4 is in contact with the base material 3 so as to be parallel to the weft 2, the varnish 4 is in the fiber direction (FIG. The air 15 in the fibers of the warp 1 can be pushed out by penetrating in the direction of arrow b). However, as for the weft yarn 2, the varnish 4 does not penetrate in the fiber direction and traps the air 15 in the fiber of the weft yarn 2 as it is, which remains inside the prepreg as voids or unimpregnated portions.

  And after making the base material 3 impregnate the base material 3 with the die coating apparatus 10 as shown in FIG. 3, this base material 3 is heated and dried with a dryer, and it is set as a semi-hardened state (B stage state). Thus, the prepreg can be continuously produced. Thus, according to the prepreg manufacturing apparatus shown in FIG. 3, it is not necessary to preliminarily depressurize the solvent in advance or impregnate the base material 3 with only the solvent in the conventional manner. The voids and unimpregnated portions remaining inside the prepreg can be reduced as compared with the prior art without lowering and cost increase.

  Hereinafter, the present invention will be specifically described by way of examples.

Example 1
As the base material 3, a long glass cloth having a thickness of 0.1 mm was used.

  Moreover, as a varnish 4, an epoxy resin (tetrabromobisphenol A type epoxy resin [manufactured by Toto Kasei Co., Ltd., trade name YDB-500]) as a solid content is 80 parts by mass, a curing agent (dicyandiamide [manufactured by Nippon Carbide Industries, Ltd.]). 3 parts by mass, a curing accelerator (2-ethyl-4-methylimidazole [manufactured by Shikoku Kasei Kogyo Co., Ltd.]) 0.2 parts by mass, and a solvent (methyl ethyl ketone (MEK)) was prepared. A resin composition was used.

  And using the prepreg manufacturing apparatus shown in FIG. 1, the prepreg was manufactured as follows. First, the varnish 4 was impregnated into the base material 3 at a flow rate of 10 mm / sec by the curtain coating device 6 while the long base material 3 was conveyed in the longitudinal direction at a speed of 10 m / min. Then, this base material 3 was immersed in the varnish 4 of the dip pan 11 (the same as what flows down from the nozzle 5 of the curtain coating apparatus 6), and the base material 3 was impregnated with the varnish 4 again. And the prepreg was continuously manufactured by changing the direction with the guide roll 14, and heating the base material 3 which came out from the varnish 4 of the dip pan 11 at the temperature of 150 degreeC with a dryer.

  However, the viscosity of the varnish 4 is changed to 1 mPa · s, 50 mPa · s, and 100 mPa · s by adjusting the amount of the solvent, and the straight line 12 in the width direction of the substrate 3 and the nozzle 5 are vertically placed on the substrate 3. A prepreg was manufactured by changing the angle θ formed with the straight line 13 formed by projecting in the direction to 10 °, 45 °, and 70 °.

(Example 2)
As the base material 3 and the varnish 4, the same materials as in Example 1 were used.

Then, using the prepreg manufacturing apparatus shown in FIG. 2, a prepreg was manufactured as follows. First, the base material 3 was impregnated with the varnish 4 at a coating amount of 20 mL / m ² by the roll coating device 8 while transporting the long base material 3 in the longitudinal direction at a speed of 10 m / min. Then, this base material 3 was immersed in the varnish 4 of the dip pan 11 (same as what is supplied to the outer peripheral surface of the roll 7 of the roll coating apparatus 8), and the base material 3 was impregnated again. And the prepreg was continuously manufactured by changing the direction with the guide roll 14, and heating the base material 3 which came out from the varnish 4 of the dip pan 11 at the temperature of 150 degreeC with a dryer.

  However, the amount of the solvent is adjusted to change the viscosity of the varnish 4 to 1 mPa · s, 50 mPa · s, and 100 mPa · s, and the straight line 12 in the width direction of the substrate 3 and the roll 7 that contacts the substrate 3 A prepreg was manufactured by changing the angle θ formed with the ridge line 16 to 10 °, 45 °, and 70 °.

(Example 3)
As the base material 3 and the varnish 4, the same materials as in Example 1 were used.

And using the prepreg manufacturing apparatus shown in FIG. 3, the prepreg was manufactured as follows. First, the substrate 3 was impregnated with the varnish 4 at a coating amount of 20 mL / m ² by the die coating apparatus 10 while the long substrate 3 was conveyed in the longitudinal direction at a speed of 10 m / min. Then, the prepreg was continuously manufactured by heating and drying this base material 3 at a temperature of 150 ° C. with a dryer.

  However, the viscosity of the varnish 4 is changed to 1 mPa · s, 50 mPa · s, and 100 mPa · s by adjusting the amount of the solvent, and the straight line 12 in the width direction of the base material 3 and the nozzle 9 are perpendicular to the base material 3. A prepreg was manufactured by changing the angle θ formed with the straight line 17 formed by projecting in the direction to 10 °, 45 °, and 70 °.

(Comparative Example 1)
In Example 1, the angle θ formed by the straight line 12 in the width direction of the substrate 3 and the straight line 13 formed by projecting the nozzle 5 onto the substrate 3 in the vertical direction is changed to 0 °, and the prepreg is changed. Manufactured.

(Comparative Example 2)
In Example 2, the angle θ formed by the straight line 12 in the width direction of the base material 3 and the ridge line 16 of the roll 7 in contact with the base material 3 was changed to 0 ° to produce a prepreg.

(Comparative Example 3)
In Example 3, the angle θ formed by the straight line 12 in the width direction of the substrate 3 and the straight line 17 formed by projecting the nozzle 9 onto the substrate 3 in the vertical direction is changed to 0 °, and the prepreg is changed. Manufactured.

  And about each said prepreg, using the transmission electron microscope (TEM) with which an electron beam is irradiated to thickness direction, the area | region where a bubble remains and another area | region are divided, and it binarizes, The former area | region The ratio (%) of the bubble remaining area to the total area (total area impregnated with varnish 4) was determined by taking the ratio of the area to the total area. The results are shown in Table 1.

表１から明らかなように、ワニス４が縦糸１と横糸２のいずれとも平行とならないように基材３に接触して含浸すると、プリプレグの内部に残留するボイドや未含浸部を従来よりも減少させることができることが確認された。

As is apparent from Table 1, when the base material 3 is impregnated so that the varnish 4 is not parallel to either the warp yarn 1 or the weft yarn 2, the voids remaining in the prepreg and the non-impregnated portion are reduced as compared with the conventional case. It was confirmed that it can be made.

  It was also confirmed that voids and unimpregnated portions can be further reduced as the viscosity of the varnish 4 is lower and the angle between the varnish 4 and the warp yarn 1 and the weft yarn 2 is closer to 45 °.

DESCRIPTION OF SYMBOLS 1 Warp yarn 2 Weft 3 Base material 4 Varnish 5 Nozzle 6 Curtain coating device 7 Roll 8 Roll coating device 9 Nozzle 10 Die coating device

Claims (4)

  When a prepreg is produced by impregnating a base material woven with warp and weft yarns and then drying the varnish, the varnish is brought into contact with the base material so that neither the warp yarn nor the weft yarn is parallel. A method for producing a prepreg characterized by being impregnated.   In an apparatus for manufacturing a prepreg by impregnating a varnish with a long base material woven with warps and wefts in the longitudinal direction, the varnish flows down in a curtain shape. The curtain coating device is provided with a nozzle for forming a varnish, and the curtain coating device contacts the base material with a varnish that flows down from the nozzle in a curtain shape so that neither the warp yarn nor the weft yarn is parallel. An apparatus for producing a prepreg characterized by being impregnated.   In an apparatus for manufacturing a prepreg by impregnating the base material with a varnish while conveying a long base material woven with warp and weft in the longitudinal direction, the varnish is supplied to the outer peripheral surface by drying it. A varnish supplied to the outer peripheral surface of the roll so as not to be parallel to any of the warp and the weft by the roll coating device. An apparatus for producing a prepreg, which is impregnated by being brought into contact with a prepreg.   A slit-like shape for discharging the varnish in an apparatus for manufacturing a prepreg by impregnating the base material with a varnish while conveying a long base material woven with warps and wefts in the longitudinal direction. A die coating device formed by providing the nozzle, and the die coating device contacts the base material with the varnish discharged from the slit-like nozzle so that neither the warp yarn nor the weft yarn is parallel. An apparatus for producing a prepreg characterized by being impregnated.

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