JPH04219213A - Fiber-reinforced resin sheet, and method and device for manufacturing same - Google Patents

Abstract

PURPOSE:To provide a fiber-reinforced resin sheet for a molding material, which has the low content (voids) of bubbles, from which small bubbles are also generated and which has excellent strength, manufacture thereof and a production device. CONSTITUTION:In a fiber-reinforced resin sheet, a fiber-reinforced material (b) is impregnated with a thermoplastic resin (a), the content of bubbles is brought to 1% or less and the major axis of bubbles is 100mum or less. The thermoplastic resin (a) is given to one surface of the fiber-reinforced material (b), said thermoplastic resin (a) is sucked from said fiber-reinforced material (b) side, said fiber-reinforced material (b) is pre-impregnated with the thermoplastic resin (a) and a first material (d) is prepared, and the first material (d) is heated under the state, in which it is pressed from the thickness direction, and the fiber-reinforced material (b) is impregnated with the thermoplastic resin (a), thus manufacturing the fiber-reinforced resin sheet. Uniform impregnation is conducted by said pre-impregnation, and the total impregnation time is shortened, and the performance and productivity of products are improved.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a molding material used for molding various products that require excellent heat resistance and creep properties, such as automobile parts, electrical parts, and daily necessities. The present invention relates to a fiber-reinforced resin sheet whose material side is impregnated with a thermoplastic resin (hereinafter sometimes simply referred to as resin), and a method and apparatus for manufacturing the same.

0002

BACKGROUND OF THE INVENTION These fiber-reinforced resin sheets can have improved strength properties by distributing fiber reinforcing materials with long fiber lengths, leading to an expansion of their uses.

[0003] Conventional methods for manufacturing fiber-reinforced resin sheets include laminating fiber reinforcing material and thermoplastic resin, heating the sheet under pressure from the thickness direction, and impregnating the fiber reinforcing material with thermoplastic resin. Thereafter, a method of cooling under pressure (see, for example, Japanese Unexamined Patent Publication No. 55-77525), a method in which a molten thermoplastic resin is supplied between the fiber reinforcing materials and superimposed in layers, and an additional layer of thermoplastic resin is added as the outermost layer of the laminate. There is a method in which a resin sheet or film is supplied and the fiber reinforcing material is impregnated with a thermoplastic resin using a belt impregnation machine equipped with a heating device, a pressure device, and a cooling device.

[0004] Regarding the latter method using a belt impregnation machine, the following two methods are known depending on the type of thermoplastic resin used. One of them is a method in which a polyester resin such as polyethylene terephthalate (hereinafter referred to as PET), which has excellent heat resistance and creep properties, is used as a thermoplastic resin, and this method is schematically shown in FIG. .

In FIG. 14, a PET sheet a and a fiber reinforcing material b formed into a mat shape are stacked in layers with the PET sheet a positioned on the outside, and the layered laminate c is dried and then molded into a roller mold. Place in impregnating machine 7. This impregnating machine 7 includes a pair of upper and lower heat-resistant metal belt conveyors 1A and 1 that convey the layered laminate c while applying pressure from its thickness direction.
B, and a plurality of heating rollers 3 that are heated via heaters 2 in the middle of the conveyance path of the pair of metal belt conveyors 1A and 1B, and the pair of metal belt conveyors 1A and 1B are
, layered laminate c in a state of being pressurized from the thickness direction by 1B
A heating and pressing device 4 that melts the PET sheet a and impregnates it into the fiber reinforcing material b by heating the PET sheet a, and a plurality of cooling rollers 5 that are configured to circulate a coolant such as water or oil into the hollow part. It is equipped with a cooling device 6 that cools and solidifies the layered laminate c heated by the heating and pressing device 4 while keeping it in a pressurized state from the thickness direction.

[0006] Furthermore, the pair of metal belt conveyors 1A mentioned above
, 1B are interlocked via a transmission device such as a gear (not shown), and are also connected to a motor 8, and are connected to the arrow x.
It is driven and rotated at the same speed in the direction.

The other method is suitable when using thermoplastic resins that do not require drying, such as polyolefin resins such as polypropylene and polymethylpentene, polyacetal resins, and ABS resins. This method is shown in Figure 15.
As schematically shown in , the thermoplastic resin a and the fiber reinforcing material b are both rolled into a roll, and the rolled thermoplastic resin a and the fiber reinforcing material b are sequentially and continuously fed out to overlap each other in a layered manner. This continuous layered laminate c is passed through a roller type impregnation machine 7 having the same configuration as that shown in FIG. 14 to continuously produce a reinforced resin material (
For example, see Japanese Unexamined Patent Publication No. 61-279518).

[0008]

[Problems to be Solved by the Invention] However, conventional fiber-reinforced resin sheets have a problem of low strength because they have a high content of air bubbles and the air bubbles are also large.

[0009] In addition, in the case of the conventional manufacturing method using the belt impregnation machine, the thermoplastic resin and the fiber reinforcing material superimposed in layers are supplied to the roller type impregnation machine 7 and pressurized from the thickness direction. Because heating starts in the state of heating and heating is mainly done through rollers, it takes a long time to fully impregnate the thermoplastic resin into the fiber reinforcement material. Not only is the productivity of the molding material low, but since the resin is heated for a long time, it tends to suffer from thermal deterioration such as thermal decomposition, which can easily impair product performance.

Moreover, since impregnation is carried out by pressing from above and below with rollers, the mechanical pressure may cause the fiber reinforcing material to shift, or the thermoplastic resin may be instantaneously, that is, locally subjected to mechanical pressure, causing the fiber reinforcing material to become impregnated. On the other hand, there was a drawback that the quality of the product became unstable due to uneven impregnation.

[0011] Accordingly, an object of the present invention is to provide a fiber-reinforced resin sheet with low cell content (porosity), small bubbles, and excellent strength. Another object of the present invention is to shorten the impregnation time to improve product performance and productivity, and furthermore, even if a thermoplastic resin having a relatively high viscosity in a molten state is used, the resin is added to the fiber reinforcement material. An object of the present invention is to provide a method and apparatus for manufacturing a fiber-reinforced resin sheet that can be uniformly impregnated with.

0012

[Means for Solving the Problems] The fiber-reinforced resin sheet according to the present invention has a cell content (porosity) of 1% or less and a cell length of 100μ or less, preferably 50μ or less. In addition, when polyester resin is used as the thermoplastic resin, the viscosity retention rate, which indicates the degree of thermal deterioration of the resin, is 80.
% or more, preferably 85% or more, and the tensile strength of the fiber reinforced resin sheet is 13.5 Kg/mm2 or more, preferably 15 Kg/mm2 or more. On the other hand, when a polyolefin resin is used, the retention rate of the melt index indicating the degree of thermal deterioration of the resin is 75% or more, preferably 80% or more, and the tensile strength of the fiber reinforced resin sheet is 10 kg/m
m2 or more.

Further, in the manufacturing method according to the present invention, after applying a thermoplastic resin to one side of the fiber reinforcing material, the thermoplastic resin is sucked from the fiber reinforcing material side, and the thermoplastic resin is applied to the fiber reinforcing material. A first material is prepared by impregnating the fiber reinforcing material with the thermoplastic resin, and then this first material is heated under pressure in the thickness direction to impregnate the fiber reinforcement material with the thermoplastic resin. In another manufacturing method according to the present invention, a thermoplastic resin is applied to the upper surface of the fiber reinforcing material with the fiber reinforcing material facing down, and then the thermoplastic resin is sucked from the fiber reinforcing material side, and the thermoplastic resin is applied to the fiber reinforcing material. A first material is made by partially impregnating the thermoplastic resin, which is then turned over so that the fiber reinforcement is on the upper side, and then heated under pressure from the thickness direction to infuse the fiber reinforcement with the thermoplastic resin. is impregnated with.

[0014] In these manufacturing methods, preferably, after producing the first material and before impregnating it, at least a thermoplastic resin of the thermoplastic resin and the fiber reinforcing material is added to the fiber reinforcing material side of the first material. A second material having a second material is applied.

[0015] The manufacturing device according to the present invention includes a first supply device that continuously supplies a thermoplastic resin on the upper side and a fiber reinforcement material on the lower side in a layered manner, and A drum mechanism that transports the fiber reinforcement material and thermoplastic resin by the rotation of a rotating drum, turns it around, and transports it out from the bottom, a heating means that heats the fiber reinforcement material and thermoplastic resin, and suction from the inside of the rotating drum during the transportation. A pre-impregnating machine equipped with a suction means to partially impregnate the inner fiber reinforcing material near the outer peripheral surface of the rotating drum with the outer thermoplastic resin to produce a first material; The fiber reinforcing material is equipped with an impregnating machine that impregnates the fiber reinforcing material with a thermoplastic resin by heating the fiber reinforcing material under pressure while being conveyed.

[0016] In the above manufacturing apparatus, before the first material is carried into the impregnating machine, a second material containing at least a thermoplastic resin of a thermoplastic resin and a fiber reinforcement material is supplied above the first material. A second supply device may also be provided.

[0017]

[Function] The fiber-reinforced resin sheet of the present invention contains almost no air bubbles, and even if it does contain air bubbles, the content is extremely low and the air bubbles are extremely small, so it has excellent strength.

Further, according to the manufacturing method and manufacturing apparatus of the present invention, the sheet is manufactured by further impregnating the fiber reinforcing material with the first material pre-impregnated with resin while suctioning. Since this pre-impregnation is quickly carried out by suction, the total impregnation time including the pre-impregnation is shorter than in conventional methods that do not involve pre-impregnation. Furthermore, by performing the impregnation by suction, the resin can be made to flow without applying pressure, and the resin can be sufficiently impregnated between the fibers of the fiber reinforcing material, thereby reducing uneven impregnation of the fiber reinforcing material.

[0019] Further, the first material after preliminary impregnation was turned over so that the fiber reinforcing material was on the upper side, and then heated under pressure from the thickness direction to impregnate the fiber reinforcing material with the thermoplastic resin. In this case, since the fiber reinforcing material is on the upper side, even if the binder fixing the fibers is melted by heating during pre-impregnation, the fibers will not fall or scatter unexpectedly.

Furthermore, after making the first material and before impregnating it, a second material containing at least a thermoplastic resin of a thermoplastic resin and a fiber reinforcing material is applied to the fiber reinforcing material side of the first material. When applied, there is no fear that the fibers will stand out on the surface of the final sheet.

[0021]

[Example] A manufacturing method according to an example of the present invention will be explained. First, a thermoplastic resin in a molten or film form is applied to one side of the fiber reinforcing material, and then the thermoplastic resin is sucked from the fiber reinforcing material side to partially impregnate it.
A first material is made by pre-impregnation. Thereafter, this first material is heated under pressure from the thickness direction using the same impregnating machine as the conventional one to impregnate the fiber reinforcing material with the thermoplastic resin.

[0022] In order to apply a thermoplastic resin to one side of the fiber reinforcing material, for example, a sheet or film made of a thermoplastic resin is laminated on one side of the fiber reinforcing material, and the thermoplastic resin is melted or softened by heating. , by a method that uniformly supplies the thermoplastic resin at a predetermined ratio to the fiber reinforcement material, such as by supplying the thermoplastic resin in a molten or softened state from an extruder through a die to one side of the fiber reinforcement material. I can do it.

[0023] Next, the above-mentioned laminate is introduced into a roll-shaped guide having a vacuum suction area, for example, and suction is applied from the fiber reinforcement side of the laminate at preferably 50 to 700 torr, more preferably 100 to 600 torr. , impregnating the fiber reinforcement with thermoplastic resin.

[0024] There is no particular restriction on the size or number of openings for sucking the thermoplastic resin in the vacuum suction area, and the degree of impregnation of the thermoplastic resin into the fiber reinforcement material is 30% or more, preferably 50% or more. It is set as follows. There is no particular restriction on the upper limit of the degree of impregnation. In order to uniformly impregnate the fiber reinforcing material with the thermoplastic resin, the number of suction openings is preferably two or more. Further, in order to prevent cooling of the thermoplastic resin during impregnation, it is preferable that the depressurized region has heat retention equipment such as a far-infrared radiant heating device. The heating temperature may be any temperature at which the thermoplastic resin used melts or softens and flows. Furthermore, in order to prevent thermal deterioration of the thermoplastic resin, the pre-impregnation time is 5 to 120 seconds, usually 10 to 120 seconds.
A range of 60 seconds is preferred.

[0025] As the above-mentioned roll-shaped guide, a mesh-shaped guide or a punched metal guide is preferably used in order to enhance the effect of impregnating the fiber reinforcing material with the thermoplastic resin. The opening of the mesh guide is the suction resistance when being suctioned,
In consideration of falling fibers of the fiber reinforcing material, the mesh size is preferably in the range of 10 to 300 mesh. Further, the hole diameter and the aperture ratio of the punching metal guide are also set in consideration of the above-mentioned points. It is preferable that these roll-shaped guides be coated with a mold release agent or that their surfaces be subjected to mold release treatment (such as coating with ceramic or fluoropolymer).

The first material, in which the fiber reinforcement is impregnated to some extent with the thermoplastic resin, undergoes this preliminary impregnation step and is then led to the same belt impregnation machine as in the prior art. As mentioned above, such a belt impregnating machine is constructed by stretching a flat belt between a plurality of rolls, for example, between two rolls, and these flat belts are arranged in pairs, one above the other. Further, it has a heat retention (heating and pressurizing) area on the side where the above-mentioned laminate is introduced, and a cooling area on the opposite side. The heat retention region is maintained at a temperature at which the thermoplastic resin melts or softens and flows, and the upper limit is, of course, a temperature at which the thermoplastic resin does not decompose. In the heat retention area, the thermoplastic resin flows in a molten or softened state, and is completely impregnated into the fiber reinforcement by the pressing force applied by the pressure roll, and air bubbles are removed.

At this time, if the amount of thermoplastic resin is small, the fibers of the fiber reinforcing material will stand out on the surface of the final fiber-reinforced resin sheet, so at the same time, the first material is introduced into the belt impregnation machine. A sheet or film made of the same type of thermoplastic resin is supplied as the second material to the non-impregnated side of the thermoplastic resin in the first material, or the same type of thermoplastic resin is melted from an extractor through a die. Alternatively, it is preferable to supply it in a softened state. As the second material, a laminate of the above-mentioned thermoplastic resin and fiber reinforcing material may be used.

On the other hand, the cooling zone is maintained below the glass transition temperature or softening point temperature of the thermoplastic resin. Therefore, the thermoplastic resin that has flowed in a molten or softened state in the heat retention area is solidified. At that time, there is no particular restriction on the degree of crystallinity when a crystalline thermoplastic resin is used.

The fiber-reinforced resin sheet thus obtained is pulled out from the conveyance section using a take-up roll or the like. The drawn fiber-reinforced resin sheet can be directly transported to a molding process or the like, or can be cut into a predetermined size and stored.

[0030] The fiber reinforcing material used in the present invention includes fibers made of inorganic compounds such as glass fibers, carbon fibers, metal fibers, and ceramic fibers, or fibers made of organic compounds such as polyvinyl alcohol fibers, polyarylate fibers, and aramid fibers. Fibers, various whiskers, etc. are used. These fibers can be used alone or in combination of two or more. From the viewpoint of heat resistance, fibers made of inorganic compounds such as glass fibers, carbon fibers, metal fibers, and ceramic fibers are preferred, and glass fibers are more economical. Further, the surface of the fiber used is preferably treated with a treatment agent that provides adhesiveness to the thermoplastic resin, such as a silane coupling agent.

[0031] There are no particular restrictions on the fiber length and fiber diameter of the fiber reinforcing material, but in order to enhance the reinforcing effect, the fiber length should be 5 mm or more.
Furthermore, 10 mm or more is preferable. In addition, the fiber diameter is preferably 2 to 50 μm from the viewpoint of good manufacturability of the fiber itself.

The forms of the fiber reinforcing material used in the present invention include woven fabrics such as plain weave, satin weave, and twill weave, knitted fabrics, unidirectionally aligned fibers, chopped strand mats, continuous strand mats, filament mats, and fibers. Any material may be used as long as it has a form such as a mat whose spaces are fixed by a binder, or a mat whose intertwining is provided to a certain degree by needling. Furthermore, these mats can also be used in combination.

[0033]Fiber reinforcing materials include fibrous substances such as short glass fibers, flaky fillers such as talc, mica, and glass flakes, glass beads, glass microballoons, granular fillers such as calcium carbonate, and wollastonite. It is also possible to appropriately mix acicular filler.

The thermoplastic resin of the present invention may also include polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polyamide resins such as nylon 6, nylon 66, and nylon 12, polycarbonate resins, and polyolefins such as polyethylene, polypropylene, and polymethylpentene. Resin, polyacetal resin, AB
S resin, polystyrene resin, polyvinyl chloride, polyvinylidene chloride, styrene-butadiene-acrylonitrile copolymer, styrene-acrylonitrile copolymer, polysulfone, polyacetal, polymethyl methacrylate, polyarylate, polyetheretherketone, polyphenylene Resins such as oxides and thermoplastic polyurethanes can be used. Among these, polyester resins, polyamide resins, and polyolefin resins are preferably used from the viewpoint of heat resistance and creep properties.

These resins may be modified and may be used alone or in combination of two or more. moreover,
Various additives for the purpose of imparting other properties, such as antioxidants, flame retardants, hydrolysis inhibitors, ultraviolet absorbers, colorants,
A crystallization nucleating agent, an internal mold release agent, a lubricant, and fillers such as flake fillers, granular fillers, and acicular fillers can be appropriately blended.

Next, a manufacturing apparatus according to an embodiment of the present invention will be explained. In FIG. 1, this manufacturing apparatus includes a first supply device 10 that continuously supplies a thermoplastic resin a on the upper side and a fiber reinforcing material b on the lower side in a layered manner;
While rotating and transporting the fiber reinforcing material b and the thermoplastic resin a supplied by the supplying device 10, heating them from both sides in the thickness direction at a temperature at which the resins melt or soften;
A pre-impregnating machine 11 that applies suction force from the side of the fiber reinforcing material b in the heated state to partially impregnate the thermoplastic resin a into the fiber reinforcing material b to produce a first material d;
a second supply device 12 for supplying a thermoplastic resin e as a second material onto the upper side of the first material d made of the first material d;
While material d and second material e are laminated and conveyed, the thermoplastic resin a is heated at a temperature at which the resin melts or softens while being pressurized from the thickness direction, so that the thermoplastic resin a is not impregnated into the fiber reinforcing material b.
and a roller type impregnator 7 for impregnating e.

The first supply device 10 includes an extrusion molding machine 1 that extrudes the melted or softened thermoplastic resin a into a sheet shape.
A mat unwinding device 10 that continuously unwinds a 0A die (only the die is shown in the drawing) and a fiber reinforcing material b wound into a roll downward from a position above the side of the die 10A.
It is composed of B.

As clearly shown in FIG. 2, the pre-impregnating machine 11 has a large number of suction holes 13a extending in the radial direction around the entire circumference of the circumferential wall, and the outer circumference of the circumferential wall is covered with a wire mesh or the like as necessary. A hollow rotating drum (roll-shaped guide) 13 protected by a mesh-like material or a punch-like material and moved and rotated in the direction of arrow R via a motor 22;
A fixed drum 23 that rotatably supports the
This drum mechanism 14 allows the mat to be unwound from the mat unwinding device 10B via the drive roller 24 on one side (right side in the drawing) of the upper part of the rotary drum 13. The fiber reinforcing material b that is supplied by Then, after preliminary impregnation is performed by suction, it is turned over and carried out from the lower part.

The pre-impregnating machine 11 is arranged around the outside of the rotating drum 13 so as to heat the fiber reinforcing material b and the thermoplastic resin a that are supplied and conveyed to the rotating drum 13 of the drum mechanism 14. , an electric heater 15 such as a far-infrared heater, and a suction device 19 for suctioning from the side of the fiber reinforcing material b. This suction device 19
These include a suction box 16 mounted on the fixed drum 23, located inside the rotating drum 13, and opening radially outward; and a vacuum pump connected to the bottom of the suction box 16 via a suction pipe 17. The pump 18 applies a suction force from the side of the fiber reinforcing material b heated by the electric heater 15 during conveyance by the rotating drum 13 to partially transfer the thermoplastic resin a to the fiber reinforcing material b. to prepare the first material d.

FIG. 3 shows details of the drum mechanism 14. In FIG. 3(A), which is a vertical cross-sectional view, a hollow fixed shaft 4
A rotating shaft 43 is rotatably supported on the outside of the rotating shaft 43 via a bearing 42, and the motor 22 (FIG. 2), the rotating shaft 43 is driven. A base end (right end) of the rotating drum 13 is fixed to the rotating shaft 43 . A fixed drum 23 is attached to the fixed shaft 41, and the distal end of the rotary drum 13 is rotatably supported by a support shaft 23a at the distal end of the fixed drum 23 via a bearing 45.

The fixed drum 23 has a through hole 46 provided only in a part of its peripheral wall, and the other part is closed. The fixed drum 23 is located opposite to the portion where the through hole 46 is provided.
A suction box 16 is attached to the suction box 1.
A suction pipe 17 is fixed to 6. Suction pipe 17
is connected to the vacuum pump 18. In this way, suction force is applied to the through hole 46.

Dual seal members 47 and 48 made of carbon seals, for example, are attached to the four sides of the suction box 16. These seal members 47,
48 is pressed against the inner surface of the rotating drum 13 by a spring member 50 pressed by the adjustment bolt 49, thereby sealing between the rotating drum 13 and the fixed drum 23. A suction hole 51 is provided in the peripheral wall of the fixed drum 23 between the seals 47 and 48, and an inner space 52 of the fixed drum 23 is provided in an inner passage 53 of the fixed shaft 41 and in the peripheral wall of the fixed shaft 41. communication hole 5
4, it is connected to a vacuum pump 18.

The suction pipe 17 is held inside the fixed shaft 41 via a holding member 55. As shown in FIG. 3(B), this holding member 55 has an axial penetrating portion 56.
The inner space 5 is
2 and the inner passage 53 are in communication.

Therefore, when the pressure inside the suction box 16 is reduced by the decompression pump 18, the air outside the suction box 16 also passes through the suction hole 51, the inner space 52, and the inner passage 53, as shown by arrow A. Therefore, air is effectively prevented from being sucked into the suction box 16 from outside, that is, from outside the through hole 46.

The fixed shaft 41 is attached to brackets 58 and 59.
It is fixed to the base 60 via.

[0046] The above-mentioned seal structure does not have to be double-layered; for example, as shown in FIG. 4, a single-layer sealing member 62 may surround the through-hole 46. In the example of FIG. 4, the suction box is also omitted, so the sealing member 62 is attached to the fixed drum 23. Air is pumped through the through holes 13a and 4 as shown by arrow B by the decompression pump 18.
6 to the inner space 52 of the fixed drum 23 and the fixed shaft 41
is suctioned and discharged through the inner passage 63.

[0047] The opening of the suction box 16 is
The suction time is 10 to 6 depending on the rotation speed of the rotating drum 13.
0 seconds, and the pre-impregnating machine 1 in Fig. 2
The preliminary impregnation rate according to No. 1 is controlled and set to be 30% or more. Further, although this pre-impregnation machine 11 is mounted on a trolley 25 and configured to be mobile, it may be a stationary type. Furthermore, the drum mechanism 14 and electric heater 15 in this pre-impregnation machine 11 are set within a furnace 26.

The second feeding device 12 is a sheet feeding device that holds the thermoplastic resin e that is formed into a sheet by an extrusion molding machine (not shown) and wound into a roll so that it can be continuously fed out. It consists of a feeding roll device.

The roller type impregnating machine 7 has the same structure as the conventional impregnating machine, in which the first material d and the thermoplastic resin e, which is the second material, are laminated, and from the thickness direction A pair of upper and lower heat-resistant metal belt conveyors 1A and 1B, such as stainless steel, which clamp, pressurize, and convey the material are provided to perform the final impregnation.

It should be noted that instead of the electric heater 15 in the preliminary impregnation machine 11, heating means such as hot air heating or high frequency heating may be used. Further, a transfer guide 27 and an electric heater 15A as shown in FIG. 2 may be provided at the connection portion for transferring the first material d from the preliminary impregnation machine 11 to the roller type impregnation machine 7.

Next, the operation of the apparatus shown in the embodiment shown in FIGS. 1 to 3 will be explained. The thermoplastic resin a extruded from the die 10A of the extrusion molding machine in the first supply device 10 and the fiber reinforcement material b continuously unwound from the unwinding device 10B are transferred to the drum mechanism 1 in the pre-impregnation machine 11.
It is continuously supplied to the top of the rotary drum 13 of No. 4 in a layered manner up and down, and as the rotary drum 13 rotates, it moves inside the furnace 26 in the direction of arrow R.
It is transported in the opposite direction, turned over, and then transported out from the bottom.

During the above-mentioned transportation, first, the electric heater 15
The fiber reinforcing material b and the thermoplastic resin a are heated, and in the heated state and above the horizontal plane including the rotation center of the rotating drum 13, the vacuum pump 18
A suction force is applied from the fiber reinforcement material b side through the through hole 13a of the rotating drum 13 via a suction device 19 consisting of a suction box 16, and the thermoplastic resin a is heated to a temperature at which it melts or softens. Due to the suction force, the fiber reinforcing material b is partially and uniformly impregnated to form the first material d. The preliminary impregnation rate at this time is preferably 30% or more. Here, since the suction position is above the horizontal plane including the rotation center of the rotary drum 13, the resin does not drip down.

Further, the first material d is inverted by the rotating drum 13, that is, the fiber reinforcing material b is layered on the upper side and the thermoplastic resin a is layered on the lower side. For example, if a mat in which the fibers are fixed with a binder is used as the fiber reinforcement material b, even if the binder melts due to heating, the fibers of the fiber reinforcement material b may fall and scatter. do not have.

Next, the drum mechanism 14 of the preliminary impregnation machine 11
The first material d carried out from the roller type impregnation machine 7 is fed between a pair of upper and lower metal belt conveyors 1A and 1B via a transfer guide 27, and at the same time is fed to a second feeding device consisting of a sheet feeding roller device. A second material, that is, a thermoplastic resin e, continuously fed out from the second material 12 is fed between the pair of upper and lower metal belt conveyors 1A and 1B so as to be superimposed on the first material d. The first material d and the thermoplastic resin e laminated in this way are conveyed by a pair of metal belt conveyors 1A and 1B and are heated by a far-infrared radiant heating device and hot air heating while being pressurized from the thickness direction. The thermoplastic resin a of the first material d and the thermoplastic resin e of the second material e in FIG. A and e are impregnated into the fiber reinforcing material b and integrated.

Here, the first material d is passed through the preliminary impregnating machine 11.
Since pre-impregnation of 30% or more has been performed in advance, the impregnation speed by the roller type impregnator 7 can be significantly increased compared to the case without pre-impregnation, and the total impregnation time including the pre-impregnation time can be shortened. I can do it. Further, since the heating time is accordingly shortened, thermal deterioration of the resins a and e can be reduced. Thereafter, the material is cooled and solidified by the cooling roller 5 while being kept in the pressurized state, and a predetermined reinforced resin molding material (fiber reinforced resin sheet) is manufactured.

In this embodiment, if the thermoplastic resin e supplied from the second supply device 12 is a resin that dislikes moisture, such as polyethylene terephthalate, a resin treated to prevent moisture absorption is used.

FIG. 5 is a schematic longitudinal sectional view showing another embodiment of the fiber reinforced resin sheet manufacturing apparatus according to the present invention. This embodiment is different from the embodiments shown in FIGS. 1 to 3 above in that the thermoplastic resin e in the second supply device 12 is
As a feeding means, a die 12A of an extrusion molding machine is provided in place of the feed roll device, and the other configurations are the same as in FIGS. 1 to 3, so the same reference numerals are given to the corresponding parts. Therefore, detailed explanation thereof will be omitted.

In the case of the embodiment shown in FIG. 5, the above-mentioned FIG.
~Compared to the embodiment shown in Figure 3, there is no need to set up a separate manufacturing line for the thermoplastic resin e film or sheet, and there is no need to take the time and effort to manufacture the sheet, resulting in lower equipment costs and manufacturing efficiency. It is more advantageous in terms of

In addition, for thermoplastic resins such as PET that require moisture removal, it is difficult to dry a film or sheet wound into a roll, and the drying equipment is generally large-scale. Moreover, the productivity of the reinforced resin molding material deteriorates due to the required drying time. From this point of view, in the case of the embodiment shown in FIG. 5, it is possible to extrude the thermoplastic resin e thinly through the die 12A, making impregnation advantageous.

FIG. 6 is a schematic vertical cross-sectional view showing an embodiment of the fiber reinforced resin sheet manufacturing apparatus according to the present invention in which a thermoplastic resin having a high melting point or softening point is used. When the film-like thermoplastic resin a is fed from the feed roll 10C and supplied onto the fiber reinforcement material b, the resin a is heated to melt or soften on the rotating drum of the drum mechanism 14 in the pre-impregnation machine 11. In order to do this, sufficient heating time must be allowed. Therefore, the drum mechanism 14 becomes large-scale, and it becomes difficult to control the viscosity of the resin.

Therefore, in order to achieve the same conveying speed as the circumferential speed of the rotary drum 13, a perforated belt mechanism 28, such as a mesh or punched belt, is used, which is wound around the outer periphery of the rotary drum 13 and uses the rotary drum 13 as a driving source. , drum mechanism 1
The rotary drum 13 and the free roller 29 are provided on the upstream side of the
By heating the resin a on the perforated belt 30 stretched between the two, sufficient heating time is ensured to promote melting or softening of the resin a, and to control its temperature or viscosity.

That is, the laminate obtained by laminating the thermoplastic resin a and the fiber reinforcing material b supplied from the supply device 10 is heated on the porous belt 30 by the electric heater 15 to a temperature sufficient to melt or soften the resin. After being heated to
The fiber reinforcing material b is partially impregnated with the resin a. In this way, when using a film-like thermoplastic resin a, by incorporating the above-mentioned perforated belt mechanism 28, there is no need to increase the heating temperature of the resin on the rotating drum 13, and as a result, deterioration of the resin can be prevented. , the quality of fiber-reinforced resin sheets is also stable.

FIG. 7 is a schematic vertical sectional view showing another embodiment of the fiber reinforced resin sheet manufacturing apparatus according to the present invention. In this embodiment, two pre-impregnation machines 11L, 1
1R is the rotating drum 13 of each drum mechanism 14L, 14R.
The rotating drums 13L, 13 of these two left and right pre-impregnation machines 11L, 11R are arranged side by side on the left and right so that they are driven and rotated in opposite directions as shown by arrows LR, RR.
A pair of drive rollers 28,
The structure is such that four layers are laminated via a roller 28, and the four-layer laminate is supplied to a roller type impregnation machine 7 via a guide roller 29. In this embodiment, the right pre-impregnation machine 11R becomes the second feeding device 12;
The material Rd is pre-impregnated with the thermoplastic resin e and the fiber reinforcing material b.

In the embodiment shown in FIG. 7, each component of the right-hand pre-impregnation machine 11R, which is the second supply device 12, and all other components are as shown in FIGS. 1 to 3. R is added to the corresponding symbol, and each component of the pre-impregnation machine 11L on the left side and the first supply device 10 are shown.
Similarly, all of the constituent elements are shown with L added thereto.

The embodiment shown in FIG. 7 has two upper and lower parts.
Two layers of fiber reinforcement b, upper and lower, between sheets of thermoplastic resin a and e
It is used in a manufacturing device for a fiber-reinforced resin sheet with a four-layer structure in which the first material Ld and the second material Rd are both pre-impregnated and then laminated.
Although the fiber reinforcement material has a four-layer structure in which no thermoplastic resin is present, the total time required for impregnation can be shortened. When the melting point or softening point of the resin extruded from the dies 10AL and 10AR is high, or when a film-like resin is used, a porous belt is installed in the preliminary impregnation machines 11L and 11R in FIG. 7 for the purpose of controlling the temperature or viscosity of the resin. A pre-impregnation machine 11 shown in FIG. 6 incorporating a mechanism may be employed.

In the embodiments shown in FIGS. 1 to 3 and the embodiments shown in FIGS. 5 and 6, the upper and lower thermoplastic resins a and e and the fiber reinforcement b interposed between them are I explained about the three-layer structure, but there are three layers in the vertical direction.
The present invention can also be implemented in a five-layer structure in which two sheets of thermoplastic resin are used and a fiber reinforcing material is interposed between each adjacent thermoplastic resin. For example, as the second material supplied from the second supply device 12 to the belt-type impregnating machine 7, two sheets of thermoplastic resin, upper and lower, and a fiber reinforcing material between them may be rolled in advance, or , they may be rolled up separately and fed out individually. Moreover, in the embodiment shown in FIG. 7, on the first material Ld conveyed from the pre-impregnation machine 11L,
A resin sheet material extruded from a die or wound into a roll and continuously fed out is laminated, and on top of that, a second material Rd conveyed from the pre-impregnation machine 11R is added.
All you have to do is laminate them. Moreover, in FIGS. 1-6, it is also possible to omit the second material e.

The fiber-reinforced resin sheet according to the embodiment of the present invention can be produced using the above-mentioned materials, for example, according to the above-mentioned production method, and by the above-mentioned production apparatus. This fiber-reinforced resin sheet has excellent strength because the thermoplastic resin is sufficiently impregnated into the fiber reinforcing material, so the cell ratio is low and the air bubbles are small.

In fact, this fiber-reinforced resin sheet has a porosity, that is, a bubble content of 1% or less, and a long diameter of the voids (bubbles) of 100μ or less, which is higher than the porosity of conventional fiber-reinforced resin sheets. 1.7% or more, the long diameter of the void is 150μ
Compared to the above, both the porosity and pore size are improved, and the strength is significantly improved.

[0069] The present invention will be specifically explained below with reference to Examples, but the present invention is not limited to these Examples in any way. In addition, the physical property values in Examples were measured by the following method. Impregnation degree (%) = {(weight of impregnated part - weight of thermoplastic resin) / weight of fiber reinforcement} x 100 Here, the weight of fiber reinforcement indicates the weight of the reinforcement used in the sample, The weight of the impregnated portion indicates the weight of the remaining portion after removing the fiber reinforcing material that is not impregnated with resin.

Viscosity retention: The thermoplastic polyester resin and the thermoplastic polyester resin in the molded article were dissolved in phenol/tetrachloroethane (weight ratio 1/1), and their intrinsic viscosity was measured using a viscometer. The value obtained by dividing the intrinsic viscosity of the thermoplastic polyester resin in the molded article by the intrinsic viscosity of the thermoplastic polyester resin was expressed as a percentage, and the degree of deterioration of the thermoplastic polyester resin was evaluated. Melt index retention rate: Calculated using the following formula from the melt index (MIo) of the polyolefin resin before molding and the melt index (MI) after molding. Melt index retention rate (%) = [1-(MI-MIo)/M
Io]×100The melt index is JIS-
It was determined according to K-7210.

Porosity (bubble content): Calculated by the following method. (1) Apply a thin layer of silicone grease to the entire surface of the test piece cut into a strip to prevent water from entering the test piece, and measure the specific gravity using the underwater displacement method. The specific gravity [A] is calculated using the following formula. [A]=(Wo×dm)/[
(Wo-Ws1)+m+(Ws-Wo)×(1-dm
/dg)] Wo: Weight of sample in air Ws: Weight of sample with silicone grease in air Ws1:
Weight of sample with silicone grease in water m: Weight of sample holding wire immersed in liquid dm: Specific gravity of water dg: Specific gravity of silicone grease (2) After measuring the specific gravity, place the test piece in a 650°C electric furnace and heat the resin. After burning and removing, the content of the fiber reinforcing material in the test piece is measured gravimetrically, and the theoretical specific gravity [B] of the test piece is calculated from the content of the obtained fiber reinforcing material. (3) Obtained above specific gravity [A] and theoretical specific gravity [B]
Therefore, the porosity is calculated using the following formula. Porosity (%) = {[B]-[A])/[B]}×100

Tensile strength: Tested in accordance with JIS-K-6911.

Size of voids (pore diameter of bubbles): Observe the cross section of the test piece using a scanning electron microscope, and measure the length of the major axis of the voids.

Examples 1 to 5 Fiber diameter 11μ, fiber length 50m
m glass fibers with an unsaturated polyester binder (
A glass chopped strand mat with a basis weight of 2,700 g/m2 was bound with
A softened resin with a thickness of 2.5 mm made of polyethylene terephthalate (PET) with a unit of deciliter/g (unit: deciliter/g) of 0.70 is supplied from an extruder, and is soaked at 300 to 310° using the pre-impregnation machine 11 shown in FIG. Table 1 while heating to C.
A first material d was prepared by partially impregnating the mat with the resin at the suction degree and suction time described in . This pre-impregnated first material d is introduced into the belt impregnating machine 7 in FIG.
While supplying the film of m as the second material e, 310
The mat was heated to 0.degree. C. to completely impregnate the mat with the resin. Next, the resin was solidified in the cooling area of the belt impregnation machine 7 to obtain a fiber-reinforced resin sheet.

The fiber reinforced resin sheet obtained had a glass chopped strand mat content of 40% by weight. In order to obtain a fiber-reinforced resin sheet having satisfactory tensile strength and resin deterioration resistance, the impregnation time in the area of the belt impregnation machine was measured and is shown in Table 1 along with the pre-impregnation degree and resin viscosity retention. The tensile strength of the sheet is 16kg/m
m2 or more, the viscosity retention rate of the resin was good at 87% or more.

Example 6 A glass chopped strand mat with a basis weight of 1800 g/m2, which was made by binding glass fibers with a fiber diameter of 11 μm and a fiber length of 50 mm with an unsaturated polyester binder (3% by weight), was coated with polypropylene (PP).
) was supplied from an extruder with a thickness of 2.5 mm, and using the pre-impregnation machine 11 shown in FIG.
The mat was partially impregnated with the above resin at the suction degree and suction time listed in Table 1 while heating at 0 to 280°C to prepare a first material d. The first material d subjected to this pre-impregnation is shown in Figure 1.
While supplying a 0.5 mm thick film made of the same type of resin as the second material e to the matte side that is not impregnated with resin, the resin is heated to 280°C to completely turn the resin into a matte. Impregnated with. Next, the resin was solidified in the cooling area of the belt impregnation machine to obtain a fiber-reinforced resin sheet. The resulting sheet had a glass chopped strand mat content of 40% by weight. In order to obtain a fiber-reinforced resin sheet having satisfactory tensile strength and resin deterioration resistance, the impregnation time in the area of the belt impregnation machine was measured and is shown in Table 1 along with the pre-impregnation degree and resin viscosity retention. The tensile strength of the sheet was 12.1 kg/mm2, and the melt index retention rate was 85%, both of which were good.

Comparative Examples 1 and 2 Fiber-reinforced resin sheets were obtained in the same manner as in Examples 1 and 6, except that the preliminary impregnation step was not performed. In order to obtain a fiber-reinforced resin sheet with a satisfactory tensile strength of 10 kg/mm2, the impregnation time in the heat retention area of the belt impregnation machine took more than 12 minutes, and the viscosity and melt index of the resin were significantly reduced. Moreover, the tensile strength of the sheet is also low.

For reference, Examples 3 and 6 and Comparative Example 1
Electron micrographs (200x magnification) of the cross section of the sheet are shown in FIGS. 8, 10, and 12, and schematic diagrams showing the main voids (bubbles) are shown in FIGS. 9, 11, and 13, respectively. As is clear from FIGS. 9 and 11, in Examples 3 and 6 of the present invention, the porosity is low and the long diameter L of the voids is also 25μ or less, whereas as is clear from FIG. In No. 1, the porosity is high, and the long diameter L of the voids also reaches 140μ.

[0079]

[Table 1]

[0080]

Effects of the Invention: The fiber-reinforced resin sheet of the present invention contains almost no air bubbles, and even if it contains air bubbles, the size of the air bubbles is extremely small, so it has higher strength than conventional fiber-reinforced resin sheets. is high. Therefore, it has become possible to apply it to applications where conventional fiber-reinforced sheets cannot be applied. Further, as explained above, according to the manufacturing method and manufacturing apparatus of the present invention, by providing a preliminary impregnation step in which the fiber reinforcing material is partially impregnated with the thermoplastic resin, the conventional fiber reinforcing material can be heated. Compared to the case of impregnating with plastic resin,
The impregnation time can be shortened, and a fiber-reinforced resin sheet with high productivity can be manufactured. In addition, since the impregnation speed is faster, the heating and keeping time of the thermoplastic resin is shortened, and the resin is not subject to thermal deterioration such as thermal decomposition, making it possible to produce a fiber-reinforced resin sheet with stable quality. In addition, pre-impregnation using suction power suppresses the generation of voids caused by residual air, etc., and makes it possible to uniformly impregnate the fiber reinforcing material with resin. , it is possible to achieve improvement in strength, that is, improvement in product performance and stabilization of quality.

[0081] Furthermore, when the vertical positional relationship of the thermoplastic resin and the fiber reinforcing material is reversed after preliminary impregnation and the fiber reinforcing material is placed on the upper side, a mat in which the fibers are fixed with a binder is used as the fiber reinforcing material. In this case, even if the binder melts due to heating and insulation, the fiber reinforcing material can be prevented from accidentally falling and scattering. From this point of view as well, stabilization of product performance and quality can be promoted.

Furthermore, after the first material is prepared by preliminary impregnation and before impregnation, if a second material containing at least a thermoplastic resin is applied to the fiber reinforcement side of the first material, the final product can be improved. This eliminates the risk of fibers standing out on the surface of the sheet, further improving the quality of the sheet.

[0083] If an extrusion molding machine is appropriately used as a feeding device to the pre-impregnating machine, sheet manufacturing equipment and manufacturing labor can be eliminated, and furthermore, in thermoplastic resins such as polyester resins that are deteriorated by moisture, This eliminates the need for resin drying equipment and drying time, and has the advantage of reducing equipment costs and further improving manufacturing efficiency.

[0084]

[Brief explanation of the drawing]

FIG. 1 is a schematic vertical sectional view showing a manufacturing apparatus according to an embodiment of the present invention.

FIG. 2 is an enlarged longitudinal sectional view of the pre-impregnation machine of FIG. 1;

FIG. 3 is a sectional view showing the drum mechanism of the pre-impregnation machine of FIG. 1;

FIG. 4 is a sectional view showing a modification of the drum mechanism of the pre-impregnation machine of FIG. 1;

FIG. 5 is a schematic longitudinal sectional view showing a manufacturing apparatus according to another embodiment of the present invention.

FIG. 6 is a schematic vertical sectional view showing a manufacturing apparatus according to still another embodiment of the present invention.

FIG. 7 is a schematic vertical sectional view showing a manufacturing apparatus according to still another embodiment of the present invention.

FIG. 8 is a microscopic photograph of a cross section showing an example of a fiber-reinforced resin sheet according to the present invention.

FIG. 9 is a schematic diagram showing the void in FIG. 8;

FIG. 10 is a micrograph of a cross section showing another example of a fiber-reinforced resin sheet according to the present invention.

FIG. 11 is a schematic diagram showing the void in FIG. 10;

FIG. 12 is a micrograph of a cross section showing still another example of a fiber-reinforced resin sheet according to the present invention.

FIG. 13 is a schematic diagram showing the void in FIG. 12;

FIG. 14 is a schematic longitudinal sectional view showing an example of a conventional manufacturing apparatus.

FIG. 15 is a schematic longitudinal sectional view showing another example of a conventional manufacturing apparatus.

[Explanation of symbols]

4...Heating and pressing device, 7...Roller type impregnation machine, 10...First supply device, 11...Preliminary impregnation machine, 12...Second supply device,
13... Rotating drum, 14... Drum mechanism, 15... Electric heater (heating means), 19... Suction device (suction means), 26...
Furnace (heating and heat retention means), 28... Porous belt mechanism, a, e...
Thermoplastic resin, b...fiber reinforcement material, d...first material, e, R
d...Second material.

Claims (8)

[Claims] 1. A fiber-reinforced resin sheet comprising a fiber reinforcing material impregnated with a thermoplastic resin, the content of bubbles being 1% or less, and the long diameter of the bubbles being 100 μm or less. 2. In claim 1, the thermoplastic resin is a polyester resin, and the tensile strength of the fiber reinforced resin sheet is 13.5 kg/mm2 or more, and the viscosity retention is 80.
% or more fiber reinforced resin sheet. 3. The fiber-reinforced resin sheet according to claim 1, wherein the thermoplastic resin is a polyolefin resin, the fiber-reinforced resin sheet has a tensile strength of 10 kg/mm2 or more, and a melt index retention rate of 75% or more. . 4. After applying a thermoplastic resin to one side of the fiber reinforcement material, the thermoplastic resin is sucked from the fiber reinforcement side to impregnate the fiber reinforcement material with the thermoplastic resin to form the first material. A method for producing a fiber-reinforced resin sheet, in which the first material is heated under pressure from the thickness direction to impregnate the fiber reinforcement with a thermoplastic resin. 5. After applying a thermoplastic resin to the upper surface of the fiber reinforcement material with the fiber reinforcement material facing down, the thermoplastic resin is sucked from the fiber reinforcement side to impregnate the fiber reinforcement material with the thermoplastic resin. A method for manufacturing a fiber-reinforced resin sheet in which a first material is prepared, the material is turned over so that the fiber reinforcement material is on the upper side, and then heated under pressure from the thickness direction to impregnate the fiber reinforcement material with a thermoplastic resin. . 6. In claim 4 or 5, after producing the first material and before impregnating it, at least a thermoplastic resin of the thermoplastic resin and the fiber reinforcement is added to the fiber reinforcement side of the first material. A method for manufacturing a fiber-reinforced resin sheet, which includes applying a second material containing resin. 7. A first supply device that continuously supplies a thermoplastic resin on the upper side and a fiber reinforcement material on the lower side thereof in a layered manner, and a first supply device that continuously supplies the thermoplastic resin in layers on the upper side and the fiber reinforcement material and the thermoplastic resin on the upper side of the rotating drum. A drum mechanism that transports the resin by rotation of the rotating drum, reverses it, and carries it out from the bottom, a heating means that heats the fiber reinforcement material and the thermoplastic resin, and a rotating drum that uses suction from the inside of the rotating drum during the above-mentioned transport. a pre-impregnation machine equipped with a suction means for impregnating the inner fiber reinforcing material near the outer peripheral surface with the outer thermoplastic resin to form a first material; and pressurizing the first material from the thickness direction while conveying the first material. An apparatus for producing a fiber-reinforced resin sheet, comprising: an impregnating machine that impregnates a fiber reinforcing material with a thermoplastic resin by heating it in a heated state. 8. In claim 7, before the first material is carried into the impregnating machine, a second material having at least a thermoplastic resin of a thermoplastic resin and a fiber reinforcement material is placed on top of the first material. A fiber-reinforced resin sheet manufacturing device including a second feeding device.