JPH08281645A - Method and apparatus for making prepreg - Google Patents

Abstract

PURPOSE: To provide a method for making a prepreg which has good thickness uniformity and resin impregnation irrespective of the basis weight of a fiber reinforcing base material sheet to be used and eliminates the generation of voids and in which the surface smoothness of both sides and the uniformity of a resin are excellent, and further provide an apparatus for the method. CONSTITUTION: A fiber reinforcing base material A sheet is supplied continuously, and one side of the material A sheet is coated uniformly with a matrix resin using the first die coater 7. Next, the reinforcing base material B is impregnated with the matrix resin on the base material B by a heating unit 9. The other side of the base material B is coated uniformly with the matrix resin using the second die coater 7'. The reinforcing base material C is heated by a heating unit 10 so that the matrix resin is semi-cured to obtain a prepreg sheet.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for producing a prepreg obtained by impregnating a sheet-shaped reinforcing substrate made of fibers with a matrix resin made of a thermosetting resin, and particularly to a sheet such as glass cloth. The present invention relates to a method and a manufacturing apparatus for manufacturing a prepreg by impregnating a filamentous fiber-reinforced substrate with a thermosetting resin without using a solvent.

[0002]

2. Description of the Related Art As a method for producing a prepreg, a hot melt method and a solvent method, which will be described below, have been conventionally known.

The hot-melt method is a two-step process in which a solvent-free resin is used, coated paper having good releasability from the resin is once coated, and then laminated on a sheet-shaped fiber-reinforced substrate. Cost is high because
Further, when the sheet-shaped fiber-reinforced base material has a heavy weight, the resin impregnation property was not good.

Further, the solvent method is disclosed in JP-A-5-320.
As disclosed in Japanese Patent No. 382, No. 382, a solvent is used to reduce the viscosity of a resin, for example, in the case of manufacturing a glass cloth epoxy prepreg for a printed circuit board used for an electric insulating material, The glass cloth is dipped in the resin, the resin is impregnated by a capillary phenomenon, and then the resin-impregnated glass cloth is dried and semi-cured.

Explaining further with reference to FIG. 5, a continuous glass cloth 102 is impregnated with a thermosetting resin in a resin tank 103, and dried and semi-cured (B) in a drying oven 105.
-Stage formation) to form the prepreg 102a, which is uniformly pressed by the pressure rolls 108 to crush the convex portions on the surface, and after crushing, radiant heating is performed by the far-infrared furnace 110, and the crushed portion and its vicinity are crushed. The prepreg is obtained by smoothing the cracked portion and the whitened portion and immediately thereafter smoothing the surface with the cooling roll 109.

However, since the solvent method uses a flammable solvent, equipment such as solvent recovery equipment and explosion-proof equipment is required. Therefore, the equipment cost is high and a small amount of solvent remains in the prepreg. There was also a quality problem due to the occurrence.

[0007]

In order to solve such a problem, a prepreg manufacturing method as described in Japanese Patent Laid-Open No. 5-200748 has been proposed. As shown in FIG. 6 and FIG. 7, the apparatus for carrying out this manufacturing method comprises a compound belt press 201.
A feeding unit 202 and an extruder 203 are provided in front of the inlet 01. In the feeding unit 202, a storage roll 204 having a glass fiber woven web not impregnated with a resin and a storage roll 205 for taking over are located. Behind the compound belt press 201, a winding unit 209 having a roll 207 for the prepreg web 206 and a take-up roll 208 is provided.

In the above apparatus, the glass fiber woven web not impregnated with resin is continuously drawn out from the storage roll 204 and supplied to the multiple belt press 201 via the deflecting roller 210. The pay-out unit 202 is further provided with another storage roll 205, and when the glass fiber woven web of the storage roll 204 is finished,
The other storage roll 205 unwinds a woven glass fiber web. In the extruder 203, the epoxy resin is melted,
The melt is passed through the wide slit nozzle of the extruder 203,
It is applied as a film to a woven glass fiber web near the diverting roller 210.

The layered product comprising the glass fiber woven web and the epoxy resin film is then introduced into the double belt press 201 and heated while being subjected to surface pressure. At this time, the epoxy resin melt penetrates the woven glass fiber web and further cures to the B-stage. At the exit of the double belt press 201, the prepreg web impregnated with the epoxy resin and pre-cured to the B-stage is cooled without adhering to the double belt press 201, and is sent out, and the roll 207 of the winding unit 209 is fed.
Or, it is continuously wound around 208.

The extruder 203 is, as shown in FIG.
It has an elongated cylinder 218 in which a screw 221 driven by a motor 220 via a reduction gear transmission 219 is located. Screw 2
The rear part of 21 is a spiral recess, which contains the mixture to be melted, which consists of flakes or powders. The hopper 222 of the extruder 203 is filled with this mixture. The epoxy resin is further conveyed by the screw 221 and melted during this conveyance. For this purpose, a plurality of heating sleeves 223 are installed so as to surround the cylinder 218. As the epoxy resin is conveyed through the cylinder 218, the epoxy resin is heated, melted and compressed so that it forms a homogeneous, viscoelastic melt at the front end of the screw 221. The epoxy resin melt flows out as a flat film having a substantially rectangular cross section through a wide slit nozzle 224 flanged to the front portion of the cylinder 218. Then, as described above, the glass fiber woven web is applied to the web near the deflecting roller 210 and introduced into the multiple belt press 201.

However, in the above apparatus, the melt residence time of the epoxy resin in the extruder 203 is long, which may cause curing troubles in the extruder. Further, the epoxy resin has a large share in the melted state, heat is generated due to the share, and moreover, there is a problem that the film forming property is not good. Further, the above apparatus required a dual belt press 201 to impregnate the glass fiber woven web with the epoxy resin melt applied to the glass fiber woven web and further cure to the B-stage. The double belt press 201 has a complicated structure, is expensive, and requires frequent maintenance and management, which eventually increases the price of the prepreg to be manufactured. Further, in the double-belt press 201, there is a problem that bubbles contained in the base material are difficult to escape to the outside because the belt is pressed from both sides of the base material coated with the resin, and voids are likely to remain in the prepreg.

On the other hand, Japanese Unexamined Patent Publication No. 57-125018
In the publication, instead of using the double belt press 201, both surfaces of a base material coated with an epoxy resin are covered with protective films so that the resin does not adhere to the base material, and a heating roll group is heated and pressed from above. Proposes a method for manufacturing a prepreg in which the base material is impregnated with the resin and the resin is cured up to the B-stage. However, this manufacturing method requires a structure in which protective films such as release paper are continuously supplied to both the front and back surfaces of the base material, and is wound up, which makes the structure of the entire manufacturing apparatus complicated and expensive. However, the protective film itself is expensive, and in the end, the manufacturing cost of the prepreg manufactured by this method must be high.

In the process of studying the above conventional manufacturing method, the present inventors have selected a matrix resin to be used, thereby using a die coater unit equipped with a backup roll and a die coater to produce a sheet-like reinforcing fiber base material. Matrix resin can be applied effectively from the front and back, stable coating work with good impregnation can be achieved regardless of the basis weight of the sheet-shaped fiber-reinforced base material, and as a result a prepreg of constant quality can be produced. I found that. The present invention is based on such a new finding.

Therefore, an object of the present invention is to shorten the melt residence time, eliminate the problem of resin curing in an extruder, have a low melt state share to prevent heat generation due to the share, and have a good film forming property. It is an object of the present invention to provide a method and an apparatus for producing a prepreg, which is capable of obtaining a composite material having uniform resin impregnation and having a constant quality continuously and at low cost.

Another object of the present invention is that, regardless of the basis weight of the sheet-shaped fiber-reinforced substrate used, the thickness uniformity and the resin impregnation property are good, voids are eliminated, and the sheet is It is an object of the present invention to provide a method and an apparatus for producing a prepreg in which the smoothness of the front and back surfaces of the reinforcing base material and the uniformity of the resin are extremely good.

[0016]

The above object can be achieved by the method of manufacturing a prepreg according to the present invention. In summary, the present invention is a method for continuously producing a prepreg in which a thermosetting matrix resin is applied and impregnated on a sheet-like reinforcing base material made of fiber, and (a) a die coater is used to substantially A first coating step in which a thermosetting matrix resin containing no solvent is uniformly applied to one surface of the sheet-like reinforcing base material in a molten state, (b) the sheet-like reinforcing base coated with the matrix resin The material is heated by a non-contact type heating unit to impregnate the sheet-like reinforcing base material with the matrix resin, and (c) the sheet-like reinforcing base material impregnated with the matrix resin is subjected to the first coating step. A second coating step in which the same thermosetting matrix resin as the above matrix resin is applied from the surface opposite to the resin coated surface, (d) the matrix resin is applied and impregnated. Heating the sheet-like reinforcing base material by a non-contact type heating unit to semi-cure the matrix resin to form a sheet-like prepreg, and (c) cutting the sheet-like prepreg into a predetermined length, or Alternatively, it is a method for producing a prepreg, which has a step of winding without cutting, and each step is continuous.

Preferably, the thermosetting matrix resin is an epoxy resin composition (A) containing an epoxy resin composed of one or more components as a main component, and an epoxy resin composition containing at least a curing agent ( B) and B) are kept in a fluid state, respectively weighed, and then uniformly mixed to prepare, and the matrix resin obtained by this mixing is supplied to the first and second die coaters. To be done. In addition, the epoxy resin composition (A) and the epoxy resin composition (B) are introduced into the hoppers of the first and second die coaters from the outlet of the composition of each storage tank, respectively. Viscosity of each resin, individually or after mixing, 1000 centipoise to 50
It is filtered at 0000 centipoise.

The above-described production method of the present invention comprises a unit for unwinding a sheet-like reinforcing base material made of fibers, an accumulator unit that operates when the sheet-like reinforcing base material is switched to enable continuous operation, and a thermosetting type. A unit for melting and continuously supplying a matrix resin, a first die coater unit having a heat-controllable hopper for coating the matrix resin on one surface of the sheet-like reinforcing base material, and the matrix A non-contact type heating unit for heating a resin-coated sheet-shaped reinforcing base material to impregnate the sheet-shaped reinforcing base material with a matrix resin, and the sheet-shaped reinforcing base material impregnated with the matrix resin, The first
And a second die coater unit having a heat-controllable hopper for coating the same thermosetting matrix resin as the matrix resin from a surface opposite to the resin coating surface by the die coater unit. A non-contact type heating unit for heating and semi-curing to form a sheet-like prepreg, and a cutter unit for laterally cutting the sheet-like prepreg into a constant length or a winding unit for winding into a roll. It is preferably manufactured by a manufacturing apparatus characterized by having.

In the above manufacturing method and apparatus of the present invention,
According to a preferred embodiment, (1) the sheet-like reinforcing base material made of fiber is a glass cloth (woven fabric), and its basis weight is 50 g / m ^{2 to} 500 g /
m ² .

(2) The matrix resin contains a bisphenol type epoxy resin containing bromine, an epoxy resin containing a small amount of a polyfunctional epoxy resin, a curing agent and a curing accelerator.

(3) The matrix resin is applied at 60% to 80% in the first coating step, and is applied at 40% to 20% in the second coating step.

(4) The viscosity of the matrix resin containing substantially no solvent is 1000 centipoise to 5000 when applied.
It is 00 centipoise.

(5) When the resin compositions (A) and (B) are mixed in a mixer and coated with a coater, the average residence time of the resin from the mixer inlet to the coater outlet is less than 20 minutes. is there.

(6) The die coater unit is a gear pump-in-die type coater in which a gear pump for measuring resin is provided in the coater, and the ratio of the resin flow line in the gear pump to the resin flow line in the coating portion is less than 3. is there.

(7) The non-contact type heating unit in the impregnation step may be an infrared heater having a wavelength of about 1 μm to 10 μm, a floating dryer for jetting a heating fluid from a plurality of nozzles above and below the substrate, or both. It is a combination type.

(8) The non-contact type heating unit in the semi-curing step is a floating dryer that jets a heating fluid from above and below the substrate through a plurality of nozzles.

(9) The heating fluid is air or nitrogen.

(10) In the floating dryer, the impregnation step is performed in the first half and the semi-curing step is performed in the second half.

(11) In the impregnation step using a non-contact type heating unit, heating is performed at an ambient temperature of 120 to 400 ° C. and a treatment time of 5 to 60 seconds.

(12) In the semi-curing step using a non-contact type heating unit, heating is performed at an ambient temperature of 120 to 200 ° C. and a treatment time of 20 seconds to 300 seconds.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The composite material manufacturing method and apparatus according to the present invention will now be described in more detail with reference to the drawings. In the following description, a glass cloth base material is used as the sheet-shaped reinforcing base material made of fibers, an epoxy resin is used as the thermosetting matrix resin, and a fiber-reinforced sheet-shaped composite material, that is, a prepreg is continuously formed. Shall be manufactured on a regular basis.

Referring to FIG. 1, there is shown a schematic configuration of an embodiment of a manufacturing apparatus for continuously manufacturing a prepreg according to the present invention.

In this embodiment, the glass cloth base material A is supplied from the unwinding device 1 into the manufacturing device. Unwinding device 1
Is provided with a roller 1'having a glass cloth base material A and a take-up roller 1 ", and an accumulator 2 is provided adjacent to the unwinding device 1. The accumulator 2 is provided between the roller 1'and the take-up roller 1". This is to operate at the time of switching and to enable continuous operation of the manufacturing apparatus. Further, a backup roller 8 is arranged next to the accumulator 2. Therefore, the glass cloth substrate A is continuously supplied to the first backup roller 8 at a constant speed by the unwinding device 1 and the accumulator 2.

A first gear pump-in-die type coater, that is, a first die coater is provided on one surface of the glass cloth substrate A which has been supplied from the accumulator 2 to the backup roller 8 at a constant speed. By 7, the epoxy resin containing the curing agent, that is, the matrix resin in the molten state which does not substantially contain the solvent is applied with a uniform thickness.

According to the present invention, a heating unit 9 is provided on the downstream side of the first backup roller 8 along the feeding path of the glass cloth base material A, and further on the downstream side thereof.
A second backup roller 8'is arranged.

The heating unit 9 is for further promoting the impregnation of the glass cloth base material B with the matrix resin applied by the first die coater 7. A floating dryer can be used as the heating unit 9. The floating dryer is a non-contact type heating unit, and as shown in FIG. 2, the heating fluid is jetted from above and below the glass cloth base material B from a plurality of nozzles 9a to float the base material B. It heats with. Further, air or nitrogen gas is preferable as the heating fluid. Further, as the heating unit 9, a so-called non-contact type heater in which infrared heaters are provided in the upper and lower portions instead of the above floating dryer, and the material to be heated, that is, the glass cloth base material B is passed through the middle portion thereof You can also do it. Infrared heater
The wavelength is preferably about 1 μm to 10 μm.
The infrared heater 9 is preferably provided with a hot air circulation device so as to increase the uniformity of the ambient temperature.

As described above, since the matrix resin is impregnated into the glass cloth base material B while passing through the heating unit 9, the ambient temperature in the heating unit 9 is 120.
The permissible range is from 0 ° C to 400 ° C and the treatment time is from 5 seconds to 60 seconds.

The second die coater 7'is a gear pump-in-die type coater similar to the first die coater 7, and has been supplied to the second backup roller 8'position at a constant speed. From the other surface of the glass cloth substrate B, that is, from the surface opposite to the surface coated with the resin by the first die coater, an epoxy resin containing a curing agent, that is, substantially no solvent in a molten state is contained. Apply the matrix resin to a uniform thickness.

The first and second backup rollers 8, 8'may be the same and, for example, SU
The surface of the metal roller made of S is made of polytetrafluoroethylene (PTF) in order to improve releasability from the resin.
E), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), hexafluoropropylene-tetrafluoroethylene copolymer (FE
It is preferable to coat with a fluorine resin typified by P) or silicone rubber, but not limited to these.
Further, it is preferable that the backup rollers 8 and 8 ′ be of a jacket type and control a constant temperature by circulating a predetermined liquid medium in the jacket, but the present invention is not limited to these.

On the other hand, in the apparatus of this embodiment, the main storage tank 3 for storing the main agent of the epoxy resin and the sub storage tank 3'for storing the resin containing the curing agent and the curing accelerator are provided.
Metering pumps 4, 4'for metering the main agent and the curing agent are connected to the respective tanks 3, 3 '. The metering pumps 4 and 4 ′ are, for example, a static mixer having a 24-stage static mixer for uniformly mixing a composition containing an epoxy resin main agent and a curing agent to obtain a desired matrix resin. 5 is connected.

As described above, according to the present invention, since the first and second die coaters 7 and 7'are arranged along the feeding path of the glass cloth base material A, the mixer. 5
Is connected to the first die coater 7 via the hopper 6 and at the same time to the second die coater 7'via the hopper 6'and the metering pump 4 ". The metering pump 4".
Limits the amount of matrix resin fed to the second die coater 7 ', and normally the amount of matrix resin from the mixer 5 is about 60 to 80% in the first die coater 7.
Preferably about 40-20% feed to the second die coater 7 '.

If the amount of resin in the first die coater is less than 60%, it becomes difficult to replace the bubbles in the base material with the resin during impregnation to remove it, and if the amount of resin exceeds 80%, the second die coater has Since the resin amount is less than 20%, it becomes difficult to apply the resin uniformly and obtain a prepreg having a smooth surface.

Therefore, according to this embodiment, first, the main resin of the epoxy resin, that is, the epoxy resin composition (A) is first stored in the main storage tank 3, and the resin containing the curing agent and the curing accelerator is stored in the sub storage tank 3 '. That is, the epoxy resin composition (B) is housed in a fluidized state, and a predetermined amount is measured by the metering pumps 4 and 4 ′ connected to the main storage tank 3 and the sub-storage tank 3 ′ respectively, and then the static mixer 5 is used. To obtain a molten matrix resin containing substantially no solvent. The matrix resin is further supplied to the first and second die coaters 7, 7'through the hoppers 6, 6 ', but preferably the epoxy resin composition (A) and the epoxy resin composition (B). Is the first from the composition outlet of each storage tank.
And during the introduction into the hoppers 6, 6'of the second die coater 7, 7 ', individually or after mixing,
Viscosity of each resin 1000 centipoise ~ 5000
It is filtered at 00 centipoise.

Further, the first and second die coaters 7,
The lip portions 7A and 7'A of 7'are arranged in close proximity to the backup rollers 8 and 8 ', and the mixer 5
The same matrix resin supplied from
A and 7'A are applied to both the front and back surfaces of the glass cloth base material, respectively.

Alternatively, instead of the mixer 5, melting,
After supplying a matrix resin composed of an epoxy resin, a curing agent, a curing accelerator, etc. to an extruder type device having a mixing function and performing operations such as melting, mixing and defoaming, the first and second die coaters 7, It can also be supplied to 7 '.

As described above, according to the present invention, the first surface of the glass cloth base material A, which is supplied from the accumulator 2 to the backup roller 8 at a constant speed, has the first surface.
With the die coater 7 of, an epoxy resin containing a curing agent,
That is, a substantially solvent-free matrix resin in a molten state is applied with a uniform thickness, and this matrix resin is impregnated into the glass cloth base material B by the infrared heater 9, and then the From the other surface of the glass cloth base material B that has been supplied to the position of the backup roller 8'of No. 2 at a constant speed, that is, from the surface opposite to the resin coated surface by the first die coater. The epoxy resin containing the curing agent, that is, the matrix resin in the molten state, which is substantially free of the solvent, is applied with a uniform thickness using the target 7 '.

Also, the first and second die coaters 7, 7'of the gear pump in die type adopted in this embodiment.
As shown in FIG. 3, the coater lip portions 7A, 7'A
Resin flow line L ₂ and the resin flow line L ₁ of the built-in gear pump
It is preferable that the ratio (L ₂ / L ₁ ) is set to 1 <L ₂ / L ₁ <3.

As a result, the flow of the resin in the width direction inside the die can be eliminated, and the discharge at the lip portions 7A, 7'A can be made uniform. Further, since the gear pump is arranged very close to the lip portions 7A and 7'A, the internal pressure of the resin rises quickly and the coating can be quickly started up. Compared to the conventional die coater, the substrate loss required for startup is about 1 /
It is 3 to 1/5. Further, the coating material ahead of the pump cannot be discharged, resulting in all loss, but the loss of the coating material is also small. Further, since it has an integrated structure, it has many advantages such as easy uniform heating by a heating medium or the like.

After mixing the main component of the epoxy resin with the resin containing the curing agent, the curing accelerator, etc., the mixture is mixed with the lip portions 7A of the first and second die coaters 7, 7 '.
The residence time until discharged from 7'A is preferably less than 20 minutes. This is because if it exceeds 20 minutes, the curing reaction partially proceeds, and it becomes difficult to make the quality uniform and stable production, and more preferably it is less than 15 minutes.

The resin viscosity at the time of coating by the first and second die coaters 7 and 7'is 1000.
It is preferably from cP (centipoise) to 500,000 cP. If the viscosity is 1000 cP or less, the metering stability of the resin by the gear pump will be poor, and the viscosity will be too low to impregnate the glass cloth base material A so much that it will penetrate into the back surface and the resin will adhere to the backup roller 8 and become stable. This is because traveling becomes difficult. Also, 500,000 cP
This is because the resin spreadability deteriorates when the value exceeds the above range, and it becomes difficult to uniformly coat the glass cloth base material A.

As the glass cloth base material A, 50 g
It is possible to apply a fabric weight of / m ^{2 to} 500 g / m ² ,
The coating amount of the matrix resin, that is, the resin amount is usually 40
It is ^{g / m 2 ~500g / m 2} . Further, as described above, the amount of the matrix resin from the mixer 5 is about 70% in the first die coater 7 and about 30% in the second die coater 7 '.
%, So that in the first coating step by the first die coater 7, the glass cloth substrate A is coated with 28% on one side.
^{g / m 2 ~350g / m 2} , usually, 35g / m ² ~32
0 g / m ^{2 is} applied, and in the second coating step by the second die coater 7 ′, 12 g / m ^{2 to} 150 g / m ² , usually 15 g / m ² to the other surface of the glass cloth base material B.
120 g / m ^{2 is} applied.

As described above, according to the present invention, since the first and second coating steps by the first and second die coaters 7 and 7'are carried out, the matrix resin is uniformly applied from the front and back of the glass cloth base material. In addition, it is applied very well without containing voids.

In the above embodiment, the first and second die coaters 7, 7'used in the present invention are designed so that the resin is discharged from the lip portions 7A, 7'A in a uniform distribution state. It is preferable that it can be controlled, and for that reason, a gear pump-in-die type die coater is used, but an ultra coat die type die coater may be used.

In this ultra coat die type coater, the lip surface of the die lip and the material to be coated (glass cloth base material) are extremely close to each other but are not in contact with each other, and the coating liquid (matrix It is characterized by the fact that resin) intervenes and flows. The matrix resin discharged from the lip slot flows out between the lip surface and the glass cloth base material. At this time, since the glass cloth base material always moves in a fixed direction at a constant speed, the matrix resin practically passes between the lip surface and the glass cloth base material. That is, the matrix resin is subjected to a large shear stress when passing through the gap between the lip surface and the glass cloth base material at a certain flow rate, causing a rapid change in viscosity to give a constant film-forming force to the glass cloth. Smoothly applied on the substrate. At this time, the flow rate of the matrix resin is determined by the pumping amount and the speed of the glass cloth base material.

Further, the glass cloth base material C coated and impregnated with the matrix resin as described above is then transferred to the floating dryer 10 via the direction changing roller 13 arranged adjacent to the backup roller 8 '. Sent. In the floating dryer 10, the matrix resin is further impregnated into the inside of the glass cloth base material B,
Then, the impregnated matrix resin is B-staged, that is, semi-cured.

Preferably, nip rollers 11, 11 'may be arranged between the direction changing roller 13 and the floating dryer 10 as shown.
The nip rollers 11 and 11 ′ are held at a constant temperature, sandwich the glass cloth base material C from above and below, and feed the glass cloth base material C coated and impregnated with the matrix resin into the floating dryer 10. Make up.
Normally, the nip rollers 11 and 11 'are 50 to 150 ° C.
And the glass cloth substrate C is 0.2 to ² kg / cm ²
Sandwich in.

It should be noted that the nip rollers 11 and 11 'are required to suppress the resin adhesion to the rollers 11 and 11', and it is preferable that the roller surface is subjected to special processing such as Teflon coating or silicone rubber covering. .

The floating dryer 10 is also used.
2 is a non-contact type, similar to the heating unit 9, as shown in FIG. 2, the heating fluid is jetted from above and below the glass cloth substrate C from a plurality of nozzles 10a, and the substrate C
Is heated in a floating state. Air or nitrogen gas is preferable as the heating fluid.

In this way, the floating dryer 1
While passing through 0, the matrix resin is semi-cured, that is, B
-Because it is staged, floating dryer 1
The ambient temperature at 0 is 120 ° C. to 200 ° C., and the processing time is 20 seconds to 300 seconds.

As described above, the glass cloth base material in which the impregnated resin is B-staged, that is, the sheet-like prepreg D is then made into a predetermined size by the sheet cutting device 20 as shown in FIG. Be disconnected. That is, the sheet-like prepreg D is cut by the slitter 21 in the width direction and 22 by the shirring in the length direction, and is stacked on the stocker 23 as a cut sheet prepreg. If desired, it can be wound without cutting with a winding device (not shown).

In the above description, the epoxy resin is used as the matrix resin, but various epoxy resins can be used as the epoxy resin, and, for example, a bisphenol type epoxy resin containing bromine as a main component is used as a polyfunctional epoxy resin. Those containing two or more kinds of epoxy resins such as those containing a small amount of resin are also preferably used, and thermosetting resins such as unsaturated polyester resins, polyurethane resins, vinyl ester resins and the like can be used in addition to epoxy resins.

Further, as the sheet-like reinforcing base material A made of fibers, in addition to the above-mentioned glass fiber cloth (glass cloth), organic fiber cloth such as aromatic polyamide fiber and aromatic polyester fiber, and carbon fiber. Similarly, a unidirectionally arranged fiber sheet of these fibers, a randomly arranged non-woven fabric sheet, or the like can also be used. Further, according to the present invention, it is possible to achieve good thickness uniformity and resin impregnability regardless of the basis weight of the sheet-shaped fiber-reinforced base material to be used. Substrate A can be used.

In the above embodiment shown in FIG. 1, the glass cloth base material C coated and impregnated with the matrix resin is arranged horizontally through the direction changing roller 13 arranged adjacent to the backup roller 8 '. Although it is configured to be fed to the horizontal floating dryer 10, as shown in FIG. 4, it is also possible to use a vertical non-contact type heating unit 10 ′ arranged in the vertical direction, and the same action and effect can be obtained. Can be achieved.

That is, the glass cloth base material C coated and impregnated with the matrix resin has one side of the heating unit 10 'arranged vertically by the nip rollers 11 and 11' arranged adjacent to the backup roller 8 '. Is introduced upward into the heating chamber 10A of the
The other heating chamber 10B of the heating unit 10 'by 15
After being introduced into the heating chamber 10B and fed downward in the heating chamber 10B, it is led out from the heating unit 10 'to the outside.
The matrix resin of the glass cloth base material C is semi-cured, that is, B-staged, while passing through the heating unit 10 '. The glass cloth base material in which the impregnated resin is B-staged, that is, the sheet-like prepreg D is fed to the sheet cutting device 20 by the direction changing roller 13 and cut into a predetermined size.

The vertical heating unit 10 'of this embodiment also has the horizontal floating dryer 10 described above.
A floating dryer similar to the above can be used, or a non-contact type heater including a heating medium heating type non-contact type heater or an infrared heater can also be used.

Also in this embodiment, the heating unit 1
While passing through 0 ', the matrix resin is semi-cured, that is,
Since it is B-staged, the ambient temperature in the heating unit 10 ′ is 120 ° C. to 200 ° C., and the processing time is 20 seconds to 300 seconds.

Next, the present invention will be described in more detail with reference to Examples.

Example 1 A composite material (prepreg) was manufactured using the manufacturing apparatus having the structure shown in FIG.

In this embodiment, the sheet-shaped reinforcing base material A made of fibers has a thickness of 180 μm and a basis weight of 205 g / m 2.
² glass cloth base materials (WE-1 manufactured by Nitto Boseki Co., Ltd.)
8K-BY-58), and was fed from the unwinding device 1 through the accumulator 2 to the backup roller 8 for coating the coater. The backup roller 8 has a roll diameter of 300 mm and is a jacket type in which a hexafluoropropylene-tetrafluoroethylene copolymer (FEP) is coated on the surface of a metal roller made of SUS in order to improve releasability from the resin. The surface temperature of the backup roller 8 was controlled to be constant by circulating a liquid medium of 35 ° C. in the jacket.

On the other hand, the composition (A) containing a bisphenol type epoxy resin containing bromine held in a liquid state at 105 ° C. in the main storage tank 3 as a main component and a small amount of a polyfunctional epoxy resin was measured by a measuring pump 4. And an epoxy resin composition containing a curing agent dicyandiamide (DICY) and an epoxy resin composition containing an imidazole-based curing accelerator (B) held at 50 ° C. in a sub-storage tank 3 ′ measured by a metering pump 4 ′. In the mixer 5, the residence time in the mixer was mixed for 1 minute to prepare a matrix resin, which was supplied to the hopper 6 kept at 105 ° C.

The resin supplied to the hopper 6 is fed to the first gear pump in die coater (L ₂ / L ₁ = 1.1) 7
Measured with the lip portion 7A of the coater, the resin viscosity is 6000 cP and the resin amount is 102 g / m on one side of the glass cloth base material A.
² was applied to a uniform thickness.

At this time, the residence time of the resin from the inlet of the mixer 5 to the outlet of the coater 7 was 10 minutes.

The glass cloth base material B coated with a resin on one surface is then provided with a plurality of nozzles 9a for injecting a heated gas up and down as shown in FIG.
The resin coated on the upper surface of the glass cloth base material B was impregnated from the inside to the lower surface of the glass cloth base material B by running for 20 seconds in the floating dryer 9 controlled at ± 2 ° C. Subsequently, the glass cloth base material B was supplied to the second backup roller 8 ′ which is the same as the first backup roller 8.

On the other hand, the same matrix resin as the one coated by the first die coater 7 was supplied to the hopper 6'while being measured by the gear pump 4 ". The resin supplied to the hopper 6'is the first one. Using a second die coater 7'which is the same gear pump-in-die coater as the die coater 7, a resin viscosity of 6000 cP and a resin amount are provided on the lower surface of the glass cloth base material B at the position of the second backup roller 8 '. Four
It was coated at a uniform thickness of 6 g / m ² .

After coating, the glass cloth base material C was sent to the floating dryer 10 via the direction changing roller 13 and the nip rollers 11 and 11 '. The surfaces of the nip rollers 11 and 11 'are covered with a hard silicone rubber, the temperature is maintained at 80 ± 1 ° C by liquid medium circulation, and the holding pressure between the nip rollers 11 and 11' is 1 kg.
Was / cm ² .

The floating dryer 10 has a plurality of nozzles 1 for injecting warmed gas up and down as shown in FIG.
The glass cloth base material C coated and impregnated with the matrix resin was run for 60 seconds in the floating dryer 10 in which 0a was provided and the ambient temperature was controlled to 180 ± 1 ° C., and the semi-curing step was carried out.

Thus, a fiber-reinforced sheet-like composite material, so-called prepreg D, in which the glass cloth base material C was completely impregnated with the thermosetting resin, was obtained and cut into a predetermined size by the sheet cutting device 20.

In the apparatus used in this example, the epoxy resin main component and the composition containing the curing agent were separately weighed and supplied, and rapidly mixed by the static mixer 5, so that the melt residence time was shortened. As a result, it was possible to prevent curing troubles in the first and second die coaters 7, 7 '.

Since the first and second die coaters 7 and 7'used are gear pump-in-die type coaters which do not have the conventional elongated cylinder and screw, the share in the melt state Was low, there was no heat generation due to shear, and the film formability was good.

Further, the obtained sheet-like prepreg D is
The thickness uniformity, resin uniformity on the front and back surfaces, smoothness, and resin impregnation property on the glass cloth base material were good, and the number of voids was 5 pieces / in ² or less when observed by magnifying 30 times. It was Further, the curing reaction rate, which indicates the degree of semi-curing, was 47%, showed no tackiness, and was excellent in handleability in the subsequent process.

Comparative Example 1 Next, the manufacturing apparatus of Example 1 (FIG. 1) was used except that the second die coater 7 ′ was not used in the manufacturing apparatus shown in the above Example 1, and the same manufacturing conditions were used. And in Example 1
A prepreg was manufactured using the same sheet-like reinforcing base material and matrix resin. However, the resin coating amount of the first die coater 7 was 148 g / m ² .

The obtained sheet-like prepreg D had good thickness uniformity and good resin impregnation property on the glass cloth base material, but the resin uniformity on the front and back surfaces was rather poor, and the smoothness on the back surface was somewhat poor. Both ends of the prepreg were slightly warped.

[0083]

As is apparent from the above description, according to the method and apparatus for producing a composite material of the present invention, the melt residence time is short, the curing trouble of the resin in the extruder is eliminated, and the share of the melt state is eliminated. Is low, heat generation due to shearing is prevented, film forming properties are good, uniform resin impregnation is performed, and a prepreg of constant quality can be continuously obtained. Furthermore, according to the present invention, regardless of the basis weight of the sheet-shaped fiber-reinforced base material used, the uniformity of thickness and the resin impregnability are good, and the occurrence of voids is eliminated, and
It is possible to continuously obtain a prepreg in which the smoothness of both surfaces and the uniformity of the resin are extremely good.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a manufacturing apparatus according to an embodiment for carrying out a method of manufacturing a prepreg according to the present invention.

FIG. 2 is a cross-sectional view showing a schematic configuration of a floating dryer.

FIG. 3 is an explanatory diagram showing a ratio of a resin streamline in a gear pump of a die coater and a resin streamline in a coating portion.

FIG. 4 is a schematic configuration diagram of a manufacturing apparatus according to another embodiment for carrying out the prepreg manufacturing method according to the present invention.

FIG. 5 is a schematic configuration diagram showing a first example of a conventional manufacturing apparatus.

FIG. 6 is a perspective view showing a second example of a conventional manufacturing apparatus.

FIG. 7 is a cross-sectional view of main parts of the manufacturing apparatus in FIG.

[Explanation of symbols]

1 unwinding unit 2 accumulator unit 3 main storage tank 3'auxiliary storage tank 4, 4 ', 4 "metering pump (metering device) 5 mixer (mixing unit) 6 hopper 7, 7'gear pump in die type coater (die coater ) 8,8 'Backup roller (decompression / suction unit) 9 Impregnation heater (heating unit) 10 Floating dryer (heating unit) 20 Sheet cutting device

Front Page Continuation (72) Inventor Hiroshi Tojima 1-3-1 Nishitsurugaoka, Oi-cho, Iruma-gun, Saitama Tonen Research Institute

Claims (4)

[Claims] 1. A method for continuously producing a prepreg in which a thermosetting matrix resin is applied and impregnated on a sheet-like reinforcing base material made of fiber, and (a) a die coater is used to substantially remove a solvent. A first coating step in which a thermosetting matrix resin not containing is uniformly applied to one surface of the sheet-like reinforcing base material in a molten state, (b) a sheet-like reinforcing base material coated with the matrix resin, A step of impregnating the sheet-like reinforcing base material with the matrix resin by heating with a non-contact type heating unit; (c) a resin-coated surface by the first coating step on the sheet-like reinforcing base material impregnated with the matrix resin. A second coating step of applying the same thermosetting matrix resin as the matrix resin from the surface opposite to the above, (d) matrix resin coated and impregnated sheet The base material is heated by a non-contact type heating unit to semi-cure the matrix resin,
Manufacture of a prepreg, which comprises a step of forming a sheet-like prepreg, and (c) a step of cutting the sheet-like prepreg into a certain length or winding without cutting Method. 2. The thermosetting matrix resin comprises an epoxy resin composition (A) containing an epoxy resin composed of one or more components as a main component, and an epoxy resin composition (B) containing at least a curing agent. And (2) and (3) are kept in a fluidized state, each is weighed, and then uniformly mixed to prepare, and the matrix resin obtained by this mixing is supplied to the first and second die coaters. The method for producing a prepreg according to claim 1, wherein 3. The epoxy resin composition (A) and the epoxy resin composition (B) are introduced into the hoppers of the first and second die coaters from the outlet of the composition of each storage tank. , Individually or after mixing, the viscosity of each resin is from 1000 centipoise to 50.
The method for producing a prepreg according to claim 3, which comprises filtering at 0000 centipoise. 4. An unwinding unit of a sheet-like reinforcing base material made of fiber, and an accumulator unit that operates at the time of switching the sheet-like reinforcing base material to enable continuous operation.
A unit for melting and continuously supplying a thermosetting matrix resin, and a first die coater unit having a heat-controllable hopper for coating the matrix resin on one surface of the sheet-like reinforcing base material. A non-contact type heating unit for heating the sheet-shaped reinforcing base material coated with the matrix resin to impregnate the sheet-shaped reinforcing base material with the matrix resin; and a sheet-shaped reinforcing base impregnated with the matrix resin. A second die coater unit having a heat controllable hopper for coating the material with the same thermosetting matrix resin as the matrix resin from a surface opposite to the surface coated with the resin by the first die coater unit. And a non-contact type heating unit for heating and semi-curing the matrix resin to form a sheet-like prepreg, and the sheet. Continuously producing an apparatus for composite material, comprising a winding unit for winding the cutter unit or a roll to transversely cut the prepreg constant length, a.